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DFA is a standalone monitoring device installed in the circuit substations of medium and high voltage distribution overhead lines and cables. It is designed to provide direct, real-time line condition information to aid field maintenance, refurbishment and replacement decision-making, safety and bushfire risk assessment, in the event of developing issues with the circuit components and what the nature of that issue is. Warnings are passed to the asset owner accordingly, whilst the captured information may be reviewed in greater depth by the system operator to assist with managing the event as efficiently as possible. A characteristic of this technology is that it can determine the occurrence of developing issues prior to these being known to the asset owner by conventional means.

The DFA Technology System consists of two main components, DFA Devices and DFA Master Station, both necessary to the basic use of the DFA Technology System. The following high-level schematic illustrates the relationship between these components. Customer is responsible for all items shown in the diagram other than the DFA Master Station and DFA Devices. Each DFA device carries out full assessment of detected disturbances and provides buffered storage of the incoming data. The DFA Devices are connected via the internet to the Master Station. The Master Station is currently a cloud-based device which provides the secure conduit and main data repository between the DFA and the customer.

dfa faq01

High-Level Schematic of the DFA Technology System

DFA has been about for about 20 years and has established many thousands of circuit years of both normal and abnormal operational condition experience over this period.

DFA technology was commissioned by the USA power industry to specifically address the real issues of fire risk reduction and a desired improvement in MV line management. The technology was never simply a research project with no end use identified at the outset. DFA was developed by the electrical engineering department of Texas A&M University (‘TAMU’) in Texas USA. Research and field demonstration have been done over the years by TAMU and EPRI (Electrical Power and Research Institute, USA), in close cooperation with multiple utility companies. Some seven patents apply to the technology.

DFA has been field demonstrated for over a thousand circuit-years. There are currently several hundred units deployed into the USA market with 66 specifically dedicated to the Texas Wildfire Mitigation Project. In addition Lord Consulting have units deployed across a number of utilities within Australia and New Zealand. Deployment projects are also undergoing planning for Australia, New Zealand and the UK. Approximately 20 distribution utilities in the USA have DFA systems in active operational duty.

This is a very important question. The DFA was conceived in its fundamental system architecture to be a field device that could always be updated as refinements were to hand based on new learning’s and field experience. DFA technology embodies over 20 years of field-proven performance based upon field-sourced events correlated with actual issues. No part of the development occurred by simple ‘theoretical’ assumptions on how real-world circuit events might look electrically. Thus, the DFA was developed with the fullest of customer cooperation and this model, as the technology is now being deployed internationally on an exponential numerical basis, will be enhanced and refined for its lifetime by regular algorithm and data assessment technology as this comes to hand from the exponential accumulation of field-verified real-world events.

In other words, DFA technology is mature but by design, will continue to evolve in sophistication via its totally unique concept of the planned and systematic integration of international deployment experiences. This concept is causing huge excitement internationally as it is an unprecedented embodiment of Industry co-cooperation on this key asset management requirement.

No other manufacturer is offering a technology which delivers the same breadth of capability and outcomes as DFA and it remains a unique concept in the market.

Yes…A full suite of detailed papers and case studies on the DFA technology in operation are available at

No technology is a panacea for all line issues, but DFA technology provides a paradigm shift in performance management for MV and HV systems. It can detect a variety of circuit failures, cable failures pre-failures, and other events. It has documented electrical signatures related to all the events outlined in TABLE 1. It features automated, mature algorithms for characterising some types of failures. Other algorithms continue to be developed and deployed.  A positive improvement in cumulative line reliability statistics (‘SAIDI’ and ‘SAIFI’) and reduction in bushfire risk is likely from the technology.

TABLE 1 Issues documented by DFA/HiZ

  • Switch and clamp failures
  • Tree/vegetation contacts
    • Contacts with primary
    • Contacts with secondary services
  • Animal induced outages
  • Fault-induced conductor slap detection
  • Voltage regulator failure
  • LTC controller maloperation
  • Recloser failures
  • Cable failures
    • Main substation cable
    • URD primary cables
    • URD secondary cables
    • Overhead secondary cables
  • Lightning arrestor failures
  • Repetitive over-current faults
  • Pole-top transformer bushing failure
  • Pole-top transformer winding failure
  • URD pad mount transformer failure
  • Bus capacitor bushing failure
  • Capacitor problems
    •  Controller maloperation
    •  Blown fuses
    •  Switch restrike
    •  Switch sticking
    •  Switch burn-ups
    •  Switch bounce
    •  Pack failure

Yes, things like recording operation and associated high resolution waveforms of reclosers that are not SCADA connected, motor starts, normal operation of switches and capacitor banks, power quality data (V, I, real / reactive power, power factor). The DFA essentially reports what is happening on the circuit, whether this is a developing fault which has not yet tripped a recloser, circuit breaker or other protection systems, or whether this is a full blown fault which has tripped the circuit. The DFA is most effective when it has been an integral part of both the engineering and operational fault management process.

Yes, there are many levels of contribution offered by the DFA:

  1. Firstly within engineering for developing issues which are identifiable by the DFA, e.g. clamps, insulators, vegetation, animal, etc. The information provided (if gathered in a timely manner) may be used to proactively locate and repair the failure prior to the issue causing a system outage.
  2. Secondly, for system issues which are not yet fully identifiable, but require monitoring should they escalate (i.e. repetitive insipient events), so that it is possible to react quickly should the event escalate or to identify that it has been cleared by some proactive maintenance work.
  3. Thirdly in operations once an event has become a full blown fault,. The locational, magnitudinal and characteristic information that is gained from the DFA during an event is used by the Operational Engineers and Fault Teams to drive the decision making process for the management of that fault.
  4. Fourthly, as an asset management tool alongside visual inspection data to identify the most optimised maintenance expenditure approach for the circuit and to confirm that system performance has been successfully improved as a result of that work being carried out.

The DFA technology is unique and unlike any other technology in current use so should not be viewed as similar to any other technology. DFA connects to conventional CTs and VTs, as do traditional monitoring devices, but it senses these inputs much more sensitively and then applies proprietary analysis to the sampled data to detect subtle events that may indicate developing problems that are not even recorded by conventional technologies. Also for this reason, data recorded by other technologies is not adequate for specialized DFA analysis. Because DFA records even subtle anomalies, it necessarily records much more data than conventional technologies. The large data volume can be managed because DFA relies on automated algorithms, rather than human effort, to report system events and health. DFA also offers selective and customer-specified reporting of events noted, be they determined by the DFA to be ‘normal’ or ‘abnormal’ events.

It should be noted that the DFA system is also capable of providing numerous conventional functions, such as logging of conventional power system quantities and other functions. Whilst certain functions may be covered by myriad discrete technologies, the DFA system advantageously provides these multiple functions in a single, unified platform and database. The integration of so many unique processing and data assembly capabilities in the DFA system make its contribution unrivaled.

No. It is not conceived as SCADA per se and was purposefully intended to run outside SCADA but as an adjunct to it. It operates as an independent web-accessed intelligent MV line monitoring system with alarms being activated by assessed line condition abnormalities and passed to the network and operation team via email, SMS, or web. DFA reports operations of station breakers, as does SCADA, but DFA also reports operations of remote reclosers and capacitors, including those without communications, by using sophisticated digital techniques to detect these operations from waveforms it measures from conventional CTs and VTs. The customer may of course choose to import DFA-acquired data into SCADA for statistical record if one wishes.

The DFA is not conceived as a standalone power quality analyser but embraces that function as a subset of its fuller capabilities. Power quality analysers primarily focus their interest upon voltage irregularities, often have set points for triggering recording or alarms, and do not make interpretations of the issues, simply recording data for later analysis by those trained in the art. The DFA technology, by converse, focuses primarily on intelligent real-time assessments of incoming circuit data of which current signatures predominate as that is where the majority of circuit abnormalities are noted, but certainly it also assesses voltage in its determinations.. DFA technology diagnoses line events via proprietary digital signal processing and reports actual interpreted findings only. The technology allows ‘high fidelity’ recordings showing minor signatures, that not being possible with a power quality device. DFA devices will record virtually all disturbances recorded by PQ devices but also will record issues that initially cause too little variation to be detected by PQ devices. The Thus, whilst appearing to be related devices, the principle of analysing and characterising waveforms is quite different.

No. DFA was conceived to work alongside protection systems but has a totally different focus and intent and nor does it offer trip functionality. Whilst sophisticated in their operation, modern protection relays still function primarily to clear present faults. Conversely, DFA reports assessed and qualified data, sometimes with probability functions attached.

The technology has not yet been tested on SWER circuits as they are not used in the USA. The designers believe the basic concepts are universal but that peculiarities of SWER circuits likely will require adaptation to detection algorithms. It is critical to note that the system design of the DFA system provides for the ability to update algorithms seamlessly, via Internet, as needed.

The DFA, unlike other proprietary fault management systems such as GFN (which actively stress the network past the normal point of failure to prove asset fitness), does not initiate faults or defects. It only reports what is actually determined to be happening with the installed network, and particularly what might be viewed as matters of actual or pending concern. The DFA merely monitors the system for the earliest signs of a developing electrical defect or fault and reports back to the utility in plain English. The defect or fault is typically on a natural glideslope to failure and left un-actioned (as with a circuit without DFA technology installed), will result in the eventual failure of the asset and system, possibly the loss of customer supplies, wildfire ignition or other hazardous situation. The DFA in no way affects the speed at which this defect or fault deteriorates, not does it prevent the defect from directly failing. The DFA assists the utility by either providing an early warning that there is an escalating defect, or providing valuable information to locate a system fault more quickly following failure. The DFA also identifies when defects or events are of a repetitive nature, allowing the utility to gauge whether the defect is escalating or stable.

DFA, similar to passive and injection Resonant Earthing systems detect the initial onset of fault currents. The principle of Resonant Earthing Systems (RES) however is that it is a reactive fault management system, operating after the fault has reached a level at which on-going normal circuit operation is not possible. In many cases, conventional protection systems are required to be de-sensitised to allow for the triggering and successful operation of RES systems prior to circuit trip / lockout. RES are also only effective on Phase to earth faults, with most Phase to Phase faults resulting in an immediate circuit trip / lockout.

DFA however operates at a much more sensitive level, detecting both phase to phase and earth faults significantly earlier than any of these other technologies. Although no single technology can be the panacea for all electrical failure events, it is the predictive ability of DFA which aligns so uniquely well with the reactive management capabilities of RES. In particular, for wild fire prone areas, a mix of both DFA and RES provides the optimal capability for the earliest detection of developing Phase to Phase and Phase to Earth electrical breakdown, whilst the RES provides security in managing those failures which develop at a rate which is too rapid to manage within the pre-failure window.

Port Hills Bush Fire 680

From the high level, to be compatible with DFA processing and algorithms, the external equipment would need to write files indefinitely at 24bits of resolution, record 200A of fault current at the device and be able to trigger on changes in magnitude of 0.5A (primary) earth fault current. 

We understand and appreciate the attractiveness of using data from existing devices, rather than adding another box to each circuit. On the surface it sounds like a great question, “We have all of these fantastic new relays and PQ meters on the system, just not the intelligence of the DFA. So why can’t we just take the DFA intelligence and use it with the equipment that we’ve got?” In answering the question, one needs to really understand what the problem is, and it comes down to the fundamental purpose of what each instrument is designed to do. Basically, although they use the same VT’s and CT inputs, PQ Meters and Relays are designed to operate in a fundamentally different fashion from DFA. The waveforms they produce are not compatible with DFA parameters, processes or algorithms. 

Specifically, PQ meters are typically designed and programmed to trigger only on large changes in voltage (e.g., a sag to 95%). Protection relays typically only record events which produce a relatively high magnitude of current (e.g., initiate their protection cycle, even if the device ultimately does not operate). Almost without exception, and by design, this produces a relatively small number of events, as measured at the substation. These events are typically limited to a few core causes, most notably conventional faults and perhaps capacitor switching events. Invariably these devices do not pickup subtle waveforms that may indicate a device is entering an incipient failure state – for example series and shunt arcing events. DFA however is designed to meet achieve the above specifications and then to be able to triage the large number of recordings to identify those events which are abnormal, repetitive or important. All of this is achieved in a matter of seconds.

This distinction is critically important, because it means that in most cases, PQ and Relay devices used as an input for waveform analysis either do not trigger at the thresholds required for detecting incipient or series arcing events, or do not record the specific information that the DFA uses to analyse the waveforms to predict the failures. The important point to stress here, because it is essential for successful waveform analytics, is that if your existing devices aren't capturing ALL events of interest (generally because they are not designed to, and are not able to be programmed to do so), then it doesn't matter what framework you use, DFA or any other platform. If you don't have the recordings, you cannot, by definition, run any waveform analysis on them.

There is also a misconception that all devices record a given waveform in more-or-less the same way. We are often asked if it were indeed possible to reprogram a Relay or PQ meter sensitivity to capture the specific waveforms required for DFA analysis, could they then be used by DFA for this purpose?   Unfortunately the answer is generally “no” and Power Solutions personnel have authored an academic research paper on this topic, which is available through the link below

Fundamentally, each waveform recording device has its own “fingerprint” associated with its recordings, based on its analogue and digital hardware, and its software programming. We often are asked for parameters such as sample rates and bits of resolution as you have asked in this case. Those are both part of a device’s “fingerprint” but many additional factors come into play e.g. analogue or digital filtering applied in the device, the maximum record length of the device, the amount of noise introduced by the electronics in the device, etc.

The critical point is that the design of algorithms and waveform analytics, particularly of the kind required for advanced event analysis and classification, requires an understanding of the specific analogue and digital processing parameters of the device which captured the original waveform being classified. Said differently, if the same event were recorded by two separate devices (e.g., an SEL-351 and a Dranetz 61000), and the same analysis algorithms were run on the outputs from those two devices, there is no guarantee that the outputs would match. This means that using signals from a variety of devices will probably work sufficiently well for analysing and locating large conventional faults, but analysing and characterizing more subtle events, series arcing, repeat events and those events which the DFA can identify to a particular source, requires knowing and accounting for the peculiarities of individual waveform recording devices. This is important to understand, because it fundamentally affects the accuracy and operation of the DFA outputs. This is why we do not allow for the import of other device waveform recordings into the DFA for analysis.

One final point. Even if all of the above could be overcome to allow for the DFA algorithms to operate to a satisfactory level of accuracy from multiple device sources, the DFA has been physically designed to take established analogue inputs and then to analyse, record and transmit relevant information to the Master Station. The design of the DFA does not facilitate the separation of the data capture, recording and analysis functions. Essentially, in its current form the DFA does not have the capability to import waveforms from other devices in isolation from its existing hardware. Such a change would be major design revision and not something which could be undertaken easily, cheaply or quickly.

FAQ Relay Paper ...

DFA devices, applied on a per-circuit basis at substation, continuously digitize waveforms from conventional CT’s and VT’s. Waveforms are recorded when anomalies are detected, even small anomalies that are ignored by conventional technologies. Advanced digital processing and patented analytical techniques, prepared from a library of over 1 million referenced issues recorded to date, are applied to each recorded waveform, with the intent of determining the power system event that caused the waveform anomaly. The techniques employed are biased so as to minimize false alarms. The substation DFA device then reports diagnosed events to a central master station, which then makes the information available to personnel, thus increasing their situational intelligence regarding the condition of the power system. The system architecture is inherently adaptable and upgradable as refinements are implemented.

Sampling rate is often asked about, sometimes in conjunction with the order of harmonics that can be resolved. The DFA sample rate is 256 points per cycle, which equates to 12,800 samples per second per channel on 50Hz systems, and is sufficient to capture the waveform data and characteristics of interest, although sample rate is not considered the most important aspect of the DFA’s data.

Also often asked is the number of bits of the DFA’s A/D converters. To answer this question properly, one must distinguish the A/D converter’s raw number of bits from its number of effective bits. An A/D converter can have a high raw bit count but, if its associated analogue circuitry is electrically noisy, a substantially smaller effective bit count, after the noise bits are considered and discarded.

Unfortunately most waveform recorders’ spec sheets provide only raw A/D bit counts and do not consider or reveal effective bits. Effective bits, also referred to as small-signal resolution, is necessary for detecting certain incipient failures, and DFA provides 18+ effective bits of resolution to make this possible. It should be noted that systems claiming to remove noise digitally, after conversion from analogue form to digital, may improve effective resolution for steady-state signals but cannot improve effective bits for transient signals, such as those important to detection of certain incipient faults and other transient conditions.

Results have been successfully recorded on line lengths of at least 200 km from the connection point to the line.

dfa faq02

Each circuit will produce a certain level of normal and abnormal ‘disturbance data’, which varies immensely from circuit to circuit. Some can produce a dozen disturbances a month, whilst others can produce several hundred. This has no direct bearing on circuit performance as some disturbances are perfectly normal operational occurrences (switching, capacitors, motor starts, etc.). In times of storms, these numbers of disturbances can increase to several thousand over a matter of days, especially if there are instances of vegetation being blown intermittently into circuits. The DFA can typically store an average of 4-6 weeks of normal data, which over a storm event can drop to a matter of days. Whilst the DFA is connected data is transmitted and then overwritten. In the event of a communications failure, data is likewise overwritten oldest to newest first. No situations have yet been encountered whereby the comms has been down for long enough to present a loss of recorded event data.

The DFA technology will typically report findings quickly in a simply-read code of characterised issues, along with associated timings. Reports are simply-read and decoded to allow a clear understanding of the issue(s) immediately. Through the decoding process and the use of the network’s own line modeling software one can determine the likely site of many reported events. If one so wishes to view it, associated waveform data is also saved with abnormal events and can be retrieved, although it is important to comment that this data generally is NOT required for a normal assessment or response to a reported event.

The DFA does not provide specific distance to fault, but for some events, does provide system event parameters such as recloser timings, magnitude, phase/ground identification, kVa and load information, as well as probable equipment details which can be used to determine the most likely location of an event on the circuit. It is also planned that an impedance to fault calculation will be included within the DFA’s capabilities within the near future.

Within an electricity system, there are no such things as a ‘false positive or negative’. There are only normal operational conditions and abnormal operational conditions which develop in amplitude and intensity at differing rates over differing periods of time. The speed of which these events develop from first indications to the point at which the circuit can no longer support normal operations (circuit protection trip event or fault) is dependent on loading, weather, mechanical and other local factors).

The DFA was designed at the outset not to report ‘false positives’…i.e. information suggesting there is an issue of concern when in fact there was no such issue occurring on the circuit. It has achieved this outcome in its many years of field-proven deployment and has done so by way of the rigour of its algorithm and signal processing technology based on these also being designed from accumulated examples of actual real-world events. In order to report an event the DFA must see a signal above a minimum level of activity and this will vary depending on several factors, but suffice it to say that its design and field experience to date has determined that below such levels of determined/reported activities, the events have not been found to have been significant. This also begs the question of the DFA’s history at missing events/information that were significant. This is a circular argument as one never would know what one did not know but the reality is that no reports have yet been made that the DFA did not see something that was patently occurring with demonstrable electrical signals and which had been determined by other means to have been the case. One final point has to be made is that the sensitivity of the DFA is typically in the 1-2 amp area of adverse modulation on circuits which can be carrying hundreds of amps of load current (which of course precludes any claims of the DFA being a partial discharge monitor or the like) but the warnings of issues, when seen, have been found to be suitably timely.

As part of the offered support for the DFA-Plus Devices, a consultant, skilled in the power distribution industry asset management field, will be selected from the LORD Consulting team and allocated to a given client by way of a formal assignment and introduction. Fundamentally, the consultant is intended to deliver the outcome of an effective implementation of the technology, such as to ensure it stays relevant to the client’s business and is expanded progressively in its implementation as a direct result.

Lord Consulting Services include:

  1. Articulate as practicable the client’s current and historic circuit issues, patterns of circuit expenditure & reliability (such things as Reliability (annual Quality of Supply spend], % Opex spent on faults, fires started, and associated statistics (including line and overall SAIDI and SAIFI).
  2. Form an agreed basis with the client as to what are the expectations for the DFA technology
  3. Agree basis for later comparison measurement of DFA contribution over historical line performances
  1. Assess operationalising requirements including (in no set order of priority):
    • change management
    • operational processes
    • training needs at all levels of the organization
    • deployment profile at the outset
    • technical matters relating to deployment (site by site, but including verification that CT ratios are suitable for permitting optimal low level signal detection by the DFA)
    • planning and agreeing monitoring and associated operational response strategies for the installed devices
    • defining and agreeing role and input methodology of PSI and LORD Consulting team in the process
    • agreeing all perceived and likely requirements for the DFA and its wider capabilities, including any special applications or contributions (e.g.: line design verification, reliability of components, and suitability of components to special environmental matters like salt spray or dust).
    • agreeing processes for maintaining operational and firmware currency of devices
    • determination and agreement of manner by which data from DFA may be integrated to all relevant areas of the client’s business
    • determination and agreement on first year (and later years) milestones & how they will be measured. This will certainly include things like line SAIDI and SAIFI on monitored circuits, comparison with earlier results, and a parallel quantified ‘balance sheet’ of ‘unlost SAIDI minutes’ and prevented SAIFI events.
  2. Work alongside client to implement the Year One plan based on the above assessment criteria, including: focus on the processes; contributions of the DFA to the operational, asset management, and commercial sides of the client’s business; training needs and responses; interpretation of DFA by client and via LORD/PSLLC interfaces; and the quality, degree, and contribution of the direct PSLLC USA interface with the client, including on any special research areas sought by the client.
  1. Continue to work with each client to hone the agreed plan for the technology rollout as it evolves in cultural, uptake, and contribution levels. This is felt to best be done annually in a formal meeting with the client at an interval agreed at the outset, most likely at the time of budgeting for the client’s next financial year, to:
    • Verify that the commitment to DFA by the client remains strong in principle and practice.
    • Confirm that the intended applications of, and expectations for, the technology have been met, to what degree (refer 8,11 above)
    • Review the documented contributions of the technology over the year (refer [e] above).
    • Document general satisfaction levels and areas of attention required
    • Review levels of training in DFA operation and response by client and assess any training or support needs in that respect
    • Consider action points to address any matters arising from the above meeting
    • Plan for the on-going utilization and implementation of the technology as it evolves in cultural, commercial, and uptake levels at each client. This would include the assessment of new applications or dynamics of the Industry (e.g.: directions set by AER, commercial fortunes of client et al) not previously considered or adopted but which might now be worth reconsideration, requirement and associated budget for more devices for coming year, and commercial business case required for the latter.
    • Assist client with possible additional business case requirements to support a more extensive DFA implementation in the coming year
  2. Convey agreed findings of the above review [h] (with timelines or any actions) to client in writing and arrange client sign off of the outcomes and action points arising by the start of each calendar year.
  3. Review relevant content of annual client review with the LORD Consulting and product supply team leaders and PSLLC in a timely manner so as to ensure client requirements are delivered and scheduled as practicable in a continuous improvement manner.

Liaise with the LORD and PSLLC product support team to address any more basic matters that might be handed to them, such as installation, commissioning, first line support, and training. The interface will also assess improvements to present levels of service.

LORD Consulting and PSLLC, offer as part of the purchase price a uniquely-conceived package of support to ensure the technology continues to remain a viable and relevant asset management tool. This support includes general on-going monitoring of the unit remotely with comment passed back promptly on pertinent issues being encountered, liaison across the operational team to the engineering team to the asset management team as to outcomes and contribution of the technology, regular generic updates as to interesting results observed from various clients, and a review of the continued contribution being made by the technology.  

Importantly, whilst the DFA itself is a continuous monitor of circuit events in near real time, Lord Consulting/PSLLC does not provide the above additional contributions via a 24hr/365 system monitoring and operational alert service.

Customers may wish to purchase additional ad-hoc support through the DFA Analysis Service on a case by case basis. The DFA Analysis Service is a fee-based service under which Lord Consulting/PSLLC assist the Customer in analysing and understanding specific DFA Data and related Circuit events and doing so more fully than provided by the propriety, automated DFA Technology software alone.

Typically not, but the DFA offers a range of capabilities and complexities of data presentation which the customer can choose to access and interact with. The data is simply interpreted by operational teams with minimal is the express policy of LORD and PSLLC that customers be trained and assisted to a level of understanding and utilization of the device as befits their expertise and interest. Optimal contribution from the DFA technology will be enjoyed by customers who make good effort to understand for themselves how to assess and interpret the contributions from the DFA.

Reports of abnormal events are displayed on a dedicated web page, which can be viewed through a secure login by a System Controller or Engineering staff. User-configurable emailed reports may also be chosen by the customer.

No. Indeed, not having to do such a thing was one of the key design parameters from the outset. The line to which it is connected can be configured or reconfigured at will with no impact on the outcomes. One can also elect to move the DFA to different circuits at will and they will work immediately they have been given the circuit name and CT/VT details, a very simple and quick process if the use of relay test blocks for connection to CT and VT is permitted.

The DFA operates as a single-ended device with very good results and very acceptable accuracy of site identification being possible. That said, customers will typically collate DFA inputs with other available data inputs from their system, such as SCADA records, customer feedback/inputs, and AMR data

One unit is required per circuit, connecting to the CT’s and VT’s in place for the line. The unit is rack mounted and purposefully powered from battery-backed 12 volts DC, typically obtained from station batteries. A high bandwidth continuously-available web connection is required.

DFA Installation Manual ...

None, apart from connection to a DC supply, connection to broadband and connection to the CT’s and VT’s, DFA does not require any specific setup. Network configuration and construction has no bearing on the determination/anticipation of faults. The DFA does not require any specific time to ‘learn’ a system, although the first month following commissioning is usually used to determine the normal operating parameters of the circuit against the nominal events that are identified. This facilitates the optimization of the DFA for the system.

DFA Installation Manual ...

No. Standard CT’s and VT’s that are currently used for the circuit protection are fine; there are no other special installation requirements. The units are designed not provide an excessive burden on these CT’s and VT’s for this very purpose. Indeed, not having to install special such equipment was one of the key design parameters from the outset. Ratio details are entered but the unit performs with a wide range of normally-used such transformers.

A ‘Master Station’ server-class PC is employed in the architecture of an installation and typically in the currently-deployed installations, the Master Station resides in the USA as a ‘cloud-based’ server. The Master Station is responsible for managing the utility company’s entire fleet of DFA devices, including collection of data, aggregation of information from multiple circuits and dissemination of reports to utility personnel. It contains both software for communicating to circuit devices in substations, as well as all website-related software, and SMS messaging functionality. For large utility companies, with large circuit counts, the “Master Station” may be split across multiple physical computers (e.g. one web server, combined with a DB server, combined with a communication server, etc.).

Each substation-based circuit device continuously connects to the central Master Station via broadband Internet. Should the data line be lost temporarily, the DFA unit has a generous buffering capability to ensure data collected during the communication downtime is not lost.

12 – 60VDC, battery-backed, typically derived from station batteries.

The DFA Master Station (whether it be a cloud-based or stand-alone server) performs a variety of functions, including the following:

  1. It provides DFA Fleet Management functions for Customer’s fleet of DFA Devices. DFA Fleet Management relies upon a properly functioning, Customer-provided network connection between each of the Customer’s DFA Devices and the DFA Master Station. DFA Fleet Management functions include:
    • Enabling the Customer to monitor the health of its fleet of DFA Devices, including detection of various problems with those DFA Devices and with Customer-provided network connections (e.g., lack of communications between a particular DFA Device and the DFA Master Station in the past week, which could indicate a problem with network service or with the DFA Device itself).
    • Deploying updated DFA Device Software to each DFA Device in the fleet, as such software updates become available.
  2. It retrieves DFA Data from Customer’s fleet of DFA Devices.
  3. It makes Customer’s DFA Data available to Customer via browser-based login, protected by Customer-specific usernames and passwords. Where Power Solutions provides Customer with DFA Master Station Service, it also makes Customer’s DFA Data available to Power Solutions personnel. Browser-based sessions between users (Customers and Power Solutions personnel) and the DFA Master Station are encrypted using https.

4. It retains DFA backup data.

Importantly the master Station does not contribute data analysis functions, that taking place entirely in the field-based DFA devices themselves

This question arises from the observation that DFA and other devices both take their inputs from CTs and VTs. That is where the commonality ends, however, as non-DFA devices do not monitor or record waveform data with the sensitivity or fidelity that the DFA employs. Further, to bring data streams of the sampling frequency and noise-free resolution needed by the DFA to a remote assessment point is not practicable, cost-effective, or sensible. For further detail, the reader is urged to review the companion discussion question, “How does the DFA technology differ from other industry technologies?”

There is no need to poll the unit manually for normal reporting and alerting to take place, with the Master Station handling that function. Events are communicated to a pre-set list of names via SMS or email. Data may be accessed at any time via the web should the user wish to interrogate the unit. Waveforms downloaded are brought in low resolution firstly and then in high resolution if sought.

The key to the conversation would be understanding specifically “What information or data” would like to be seen within SCADA? Fundamentally, the kind of data collected, analysed and supplied by the DFA isn’t SCADA data, or even typically data that is compatible with a SCADA system. That’s not just file type compatibility, moreover the physical operational process of what DFA collects, how it analyses it and then how it reports it. This aspect, as far as we are aware, is not physically or philosophically compatible with what SCADA systems require or how they work, so DNP3 compliancy may not even be viable or even possible. The  protocols mentioned above are typically used for RTUs and other SCADA devices and do not meet the needs of the DFA in operation or philosophy. The DFA is designed primarily as a ‘stand alone’ system which communicates within its own dedicated structure. It is not designed to interact with any other system, or provide outputs for SCADA, and there are no plans for this functionality at this stage.

DNP3 / MODBUS were designed, primarily, to be used by industrial control systems, and as such they are generally good solutions for the kinds of communication these devices do (i.e.: SCADA - polling, synchronous, relatively low data rate, etc.). They are not designed and aren't suitable for the kinds of communication the DFA requires: asynchronous, interrupt-driven, high data rates (by RTU standards), file transfers, etc.).

IEC 61850 was designed primarily as a protocol to allow various substation devices to talk to each other in a producer / consumer multicast fashion. Again, IEC 61850 is good for what it's designed to do, but its structure tends to be geared around applications very different from DFA: primarily relaying and synchro-phasors. 

DFA devices communicate using standard protocols, but protocols that are more directly suited to the kinds of communication required by DFA functionality. Specifically, DFA communication between units and the master station uses HTTPS (using TLS 1.2 for transport, with messages further encrypted by JWT where authenticity is enforced with a public / private key pair unique to each unit) and SFTP (for files). Both of these can be further tunnelled through IPSec (see the current working group in IEEE SA SO/P2030.102.1)

The makers prefer to have remote web access to data from the system but it is not essential. They offer associated support to users and it has been a popular service. Such support is included in the unit price of the DFA device.

Yes. The manufacturers include this as part of the standard support, if granted web access to do so.

Initial implementation will be followed by a training and orientation service primarily delivered by LORD Consulting with contribution also from Power Solutions LLC USA. It will include scenario modelling and training on how to turn the information provided into efficient responses on the network. It is expected that those trained will include the field operations team through to the senior engineering team. Over time, it is expected that the utility itself would develop their own experience and ability supported by Lord Consulting to monitor and interrogate the DFA data at an increasing level. A vital training contribution is via User Groups and these are being established in each country of deployment.

As the unit will uniquely inform of issues and in many cases well ahead of any other corroborating data from conventional technology or customer complaints or the like, it will facilitate a greatly enhanced level of operational response. Given the increased level of event detail supplied by the DFA, this is also the case even if an event occurs that may not have been foreseeable (such as a storm-induced issue). In addition, experience to date has shown responses often can be made in a more timely and cost-effective manner (ahead of an actual failure to follow), in daylight hours, and in a much safer manner. The improvement in line failure and outage statistics as a result of the technology can be dramatic, as will be customer and stakeholder relations.

DFA waveform files are provided in an IEEE standard (1159.3) PQDiff format.

You will, through your Master Station login, have the ability to download single event waveforms in the PQDiff format. We can provide the occasional files in Comtrade format, on an as-needed basis for one off exceptional events, or we can supply you with a tool that will dump the all of the chosen PQDiff files into a CSV.

There are several main factors determining the initial uptake of DFA units. Firstly, there is a level of operationalising effort that is required and that is independent of DFA numbers. Second, there is a clear need to have sufficient installed base of DFA units to ensure an adequate flow of data from them in a sensible time period to allow their performance to be tested and assessed. Thirdly, when customers also wish to enhance the initial implementation with a special project site installation (e.g.: to gain experience on SWER circuits) enough units also need to be allocated to the project sites as well as the ‘mainstream’ ones to ensure a good assessment of the data flow. Field experience in the USA over many years of installations suggest that the initial installed base would be in the area of at least 6-10 pieces, with more optimal assessments being when 5-10% of the circuits owned by a network are so monitored.

LORD Consulting will be engaged by the local suppliers LORD Power Equipment) in NZ, Australia, and the UK, to liaise with the asset management team to select the installation sites, prepare the installation details at each site, arrange any necessary training of staff and change management required. Installation would be intended to be done by the distribution company or its preferred contractor.

LORD Consulting and PSLLC, offer as part of the purchase price a uniquely-conceived package of support to ensure the technology continues to remain a viable and relevant asset management tool. This support includes general on-going monitoring of the unit remotely with comment passed back promptly on the issues being encountered, liaison across the operational team to the engineering team to the asset management team as to outcomes and contribution of the technology, regular generic updates as to interesting results observed from various clients, and a review of the continued contribution being made by the technology. It is important to note that this service is not intended as an inclusive 24hr/365 system performance monitoring service.

Lord Consulting would be happy to supply the names of referee companies for you to contact if this is desired.

Customer Testimonial ...

Please refer to sections 8 (DFA Cyber security and Software Maintenance) and 9 (DFA Data Backup and Retention) of the DFA Technology System Manual. We are unable, by means of confidentiality to provide specific client details of security protocols.

DFA Technology Systems Manual ...

Data volume varies with level of circuit activity. In a very active month (e.g., a month with multiple storms or a month with a repetitive, low-amplitude, incipient condition) data volume could be several times as much as it is in a “quiet” month. We generally recommend 10GB/month/device. In the USA, certain utility companies are able to “pool” their data volume, so that a particularly active month on one circuit does not cause an overrun of that circuit’s monthly allotment while the other circuits use only a small fraction of their allotments. We do not recommend sharing a cellular modem between multiple DFA devices, but we do recommend that the utility explore options, with its service provider, about pooling data allotments across multiple cellular modems. It is especially important to start with a relatively generous allotment on three-wire, 50 Hz circuits, because, as has been discussed previously, it is recognized that software adaptations will be necessary for recognition of certain types of circuit events. Design, implementation, and testing of software adaptations, particularly for repetitive, low-amplitude, incipient conditions, fundamentally require sufficient data, from operating circuits, during such conditions. The approach to collect this data, while minimizing the probability of events important for enabling the adaptations, is to trigger very sensitively, which in turn means that the amount of data collected and transmitted during this phase will be higher than it might be during long-term, normal operations. Because it is not possible to predict the level of circuit activity, we recommend the 10GB figure listed above but cannot guarantee that it will not ever be violated.

The basic requirement is to provide Internet service, to each DFA device, that allows the device to connect to and maintain a connection with the DFA Master Station. Utilities have used a variety of means to do this, including fiber, DSL, and cellular modems. Lord Consulting/PSLLC can speak only generally to various implementations, and for confidentiality, cannot provide details of client specific security related implementation questions.

Several utilities use DFA route connections from DFA devices from substations to a central location (e.g. Utility headquarters) through IPSEC tunnels, then allow the data to traverse the internet to PSLLC's server. Lord Consulting/PSLLC again notes that all traffic between the DFA device and master station is encrypted using TLS channels. If a client requires to further encapsulate that traffic in a single IPSEC tunnel (or similar VPN technology, such as OpenVPN) in transit to PSLLC's server, it would be something we could discuss. The preference however is that each DFA device connects to the DFA Master Station directly, using an encrypted connection with no intermediaries.

There are a variety of reasons we would prefer not to implement this particular topology, and would prefer the one proposed in the above FAQ. Lord Consulting/PSLLC would be open to implementing a similar VPN technology (i.e. OpenVPN) between devices and master station.

Data files recorded by the DFA are recorded in industry-standard PQDif format, with compression enabled in the files. Additional compression would yield little benefit and is not supported by the DFA device-to-master communications protocol. The DFA Master Station web interface provides means to access all user data; the utility does not need to acquire any special software for this purpose.

Each DFA device establishes and maintains a connection to the DFA Master Station. That connection then supports encrypted, bidirectional data flow between the device and the Master. The Master does not establish connections inbound to the substation-based DFA device. Therefore there is no requirement for the substation firewall to have any inbound ports open. Also please refer to General Response above.

The DFA Master Station pushes updated software to the fleet of DFA Devices. This is done on an as-needed basis, averaging approximately once per month.

DFA Technology does not collect, analyse, store or transmit any information of a personal or private nature regarding any single or group of individuals, or as specified within any Privacy Legislation.

DFA operates by collecting and analysing internally the feeder phase voltage and current parameters, to identify developing fault events. This information is fully encrypted and transmitted using a unique DFA identifier which does not identify the company, feeder or location of the DFA.

Lord Consulting Ltd and Power Solutions LLC treat all data with the utmost privacy and security. Data or analytics is only used for the specific purpose of which the technology was designed and is not shared external to the clients organisation without the clients express and prior permission. In addition to this both Lord Consulting Ltd and Power Solutions LLC are happy to operate under the additional cover of an individual Non Disclosure Agreement with the client company if this is desired.

Further details on the specifics of Data Security Protocols are explained within the ‘Information and Data Security’ Section of this FAQ.

Please refer to sections 8 (DFA Cyber security and Software Maintenance) and 9 (DFA Data Backup and Retention) of the DFA Technology System Manual.

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All data is fully encrypted in transmission and storage. Please refer to sections 8 (DFA Cyber security and Software Maintenance) and 9 (DFA Data Backup and Retention) of the DFA Technology System Manual.

DFA Technology Systems Manual ...

The data collected by the DFA would remain the property of the utility. The Utility in turn consent to grant Lord Consulting and PSLLC (DFA Manufacturer) a free and exclusive right to use this data for delivery of specific services. i.e

  • Lord Consulting/PSLLC has the right to use the client’s data for the purpose of assessing the performance of DFA algorithms and for the purpose of designing and testing improvements to algorithms
  • Lord Consulting/PSLLC reserves the right to use data obtained from client DFA systems, including the right to publish case studies and the like, provided the client is not identified.

The scope of customer consent includes Lord Consulting/PSLLC collecting customer DFA Data, analysing it, and using it today and in the future for product improvements (for-profit commercialization) and industry research and publications, and, upon customer request that Lord Consulting provide DFA Analysis Service, use of customer DFA Data for the purposing of enabling us to perform such services.

If you neither use the DFA Master Station Service nor request that Lord Consulting/PSLLC review customer DFA Data, then Lord Consulting do not collect customer DFA Data; however, if you use our DFA Master Station Service or request our DFA Analysis Service, then Lord Consulting collect customer DFA Data. Data includes Electrical current and voltage waveform data, sampled by DFA Devices, and reports generated by Power Solutions proprietary software acting on that waveform data.

Lord Consulting may use customer DFA Data for the purpose of developing algorithms, improving our commercial products and, upon request by you, to assist you with DFA Analysis Service. Additionally, customer DFA Data will be included with similar DFA Data collected from other Customers and may be shared with the Texas A&M Experiment Station (TEES) and their affiliates for their research projects. These research projects may, or may not, be disclosed anonymously in industry publications (identifiable data would only be disclosed publically with the consent of the utility concerned).

Lord Consulting do not monitor or review customer data on a real-time, daily, weekly, monthly, or annual basis in order to determine if customer Circuits are defective, down, or otherwise experiencing a dangerous condition or other problem. Lord Consulting are not a “home or business security” service provider that monitors customer home or business on a 24x7 basis or contacts you if the hardware and or software installed in customer home or business signals a problem. You are responsible for reviewing customer DFA Data, at intervals that customer experience deems appropriate, to determine whether customer Circuits are experiencing a problem. If you contact us regarding a specific issue involving customer Circuits, Lord Consulting may review customer DFA Data and assist you in interpreting that DFA Data related to customer Circuits. In the course of reviewing customer DFA Data for the purpose of improving our products, in the event that Lord Consulting discover an indication of a possible Circuit event or condition that Lord Consulting believe may be of interest to you, Lord Consulting may, at our discretion, initiate contact with you regarding that event or condition, but Lord Consulting have no responsibility to do so, and doing so in one instance creates no obligation or expectation that Lord Consulting would do so for future events.

Please refer to sections 8 (DFA Cyber security and Software Maintenance) and 9 (DFA Data Backup and Retention) of the DFA Technology System Manual.

DFA Technology Systems Manual ...

Lord Consulting/PSLLC may publish customer lists, to include the name of your company and the approximate number of DFA Devices and related services you have purchased or are contemplating purchasing, which will be in the nature of a customer list, press release and or marketing material. In addition Lord Consulting/PSLLC may publish research papers, reports or publications which include descriptions, summaries, and analyses that use DFA Data from customer Circuits. In doing so, the name of your company and your employees shall not be disclosed in conjunction with specific, traceable examples of DFA Data. Lord Consulting/PSLLC and its affiliates do not otherwise disclose the name of your company in its reports, except with your permission or in publications made jointly with you or your employees.

Distribution Fault Anticipation technology.

A hardware and software system for the practice of DFA Technology and consisting of a DFA Master Station and a fleet of one or more DFA Devices.

DFA Master Station Hardware, loaded with DFA Master Station Software and acting as a fundamental component of the DFA Technology System. The Master Station is currently a cloud-based device residing in the USA, which provides the secure conduit and main data repository between the DFA and the customer.

Proprietary, DFA Technology System-specific software, provided by PSLLC, necessary for the DFA Master Station to perform its intended purpose, and not including operating system software or any other third-party software.

An appropriately specified computer or system of computers, not proprietary to PSLLC, on which DFA Master Station Software is installed and used. DFA Master Station Hardware may consist of a single computer or of multiple computers configured to operate as a functional unit.

A fee-based service that provides the functionality of a DFA Master Station.

A specific device, of proprietary design, that constitutes a fundamental component of the DFA Technology System.

Proprietary, DFA Technology System-specific software, provided by PSLLC, embedded in and running on DFA Device Hardware. DFA Device Software is available only as an integral component of DFA Devices, not as standalone software.

Hardware of proprietary design, to provide the sensing, computing, communications, and other requirements for running DFA Device Software; does not include power supplies, wiring, communications equipment, or other apparatus, except as embedded in and integral to the DFA Device Hardware itself.

A function of the DFA Technology System, whereby a DFA Master Station provides oversight and management functions for a fleet of DFA Devices.

A three-phase electrical circuit, operating at distribution voltage (i.e., from 1 kV to 35 kV), for conducting electricity from a distribution substation to electric loads; also known as a Circuit.

An electric power distribution company or an entity performing power delivery functions typically ascribed to an electric power distribution company.

Electrical current and voltage waveform data, sampled by DFA Devices, and reports generated by PSLLC proprietary software acting on that waveform data.

An end user of the DFA Technology System; typically, a Distribution Company; excludes agents and resellers.

Service provided by PSLLC, upon request by Customer.

Power Solutions LLC, a Texas Limited Liability Company and supplier of DFA technology.

Lord Consulting and PSLLC personnel have individual user IDs. All logins are logged. Upon request by a Customer, PSLLC can make available logs related to Customer’s data, for a nominal period of time (e.g., one week).

PSLLC performs internal penetration testing on its networks. Upon request by Customer, PSLLC can supply a list of vulnerabilities found and remediation steps taken.

PSLLC does not automatically notify each Customer of changes to servers, including use of collocated or cloud resources, but generally will respond to Customer’s request for information about current configuration.

Access to DFA Data is determined by each user’s login credentials. Customer and Lord/PSLLC login IDs have access to Customer’s DFA Data.

DFA Master Station Service is not to be deemed to be critical to operations, and Power Solutions does not represent that DFA Master Station Service will have 100% availability.

Each DFA Device contains an internal firewall which is configured to drop all connection attempts. The DFA Device’s internal firewall is not configured to log such attempts. Customer may choose to configure its own firewall in front of the DFA Device to provide additional security and monitoring.

PSLLC patches the operating system software of the DFA Master Station Service, generally within a week of patches being made available the operating system vendor. PSLLC monitors the National Vulnerability Database and MITRE's CVE database to determine the criticality of individual vulnerabilities. PSLLC does not generally notify Customer of patching activities but can make a reasonable level of information available to Customer upon specific request.

The connection between each DFA Device and the DFA Master Station is via a high bandwidth web connection which is supplied by the utility. This could be either via the substation communications or a standalone comms connection. Lord Consulting can supply high end Cell modems suitable for interface with the DFA Ethernet port to the Internet as part of the supply contract. The supplied price was for hardware only and excludes installation and the on-going communications charges/plan. The utility is fully responsible for provision and maintenance of the network connection between DFA Devices and the DFA Master Station.

Each DFA Device has a factory-assigned GUID. The Master Station maintains a white list of these GUIDs. Each DFA Device establishes and maintains a connection to the Master Station. Bidirectional data transfers use that connection. The Master Station does not initiate a connection to the DFA Devices.

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