Successful fault level prediction trials

Outram Research has confirmed that trials with Scottish Power Energy Networks (SPEN) and Western Power Distribution (WPD) to test and validate an entirely original solution to determine peak fault current on the electrical network have been a success.

The Outram Fault Level Monitor (FLM), which predicts the RMS and peak fault current by passively monitoring disturbances on the transmission and distribution networks during normal operation, is a more cost-effective and potentially more accurate approach than existing methods. The compact device allows users to take measurements on the live network and calculate a fault level value at that measurement point using both upstream and downstream information. The user is presented with a full fault level overview including real time fault level predictions, the trend and average values over a time period such as 30 minutes.

The new product can help improve network safety by accurately predicting fault current and revealing potential fault level issues, in turn helping operators make better investment decisions and simplifying the connection and management of distributed renewable power generation. Network operators will be able to identify the fault level in areas of the network where network modelling may be difficult or non-existent, verify the adequacy of network breakers and resolve fault level problems more quickly. Applying the Outram FLM to Active Network Management schemes is further demonstrating the commercial viability, flexibility and general potential of the Outram FLM for electrical distribution companies worldwide.

Field trials with SPEN demonstrate that the Outram FLM can consistently and accurately calculate fault current in real-world applications. The results are within 5% of the values produced by computer modelling, which has previously generated the most accurate fault level calculations available. In fact it is possible that the values produced by the Outram FLM are more accurate than the modelled values.

Managing Director of Outram Research, John Outram, said: “We are delighted with the success of the trials. The possibility of having an instrument that predicts the value of the maximum fault level on their networks, at every voltage level, is generating much interest among Distribution Network Operators (DNOs). The Outram FLM is a unique solution which meets a need that, up until now, has remained unfulfilled. The equipment is the size of a lunchbox so can be deployed quickly and easily and moved from site to site by a single engineer. We have worked very closely with SPEN on the requirements and with additional help from another UK DNO, Western Power Distribution, we aim to deliver a solution with all the functionality required by operators worldwide.”

Western Power Distribution (WPD) is planning to take the Outram FLM one step further. With a vision for an Active Network Management solution, WPD aims to introduce a means of supplying the FLM with a small, non-customer-affecting network disturbance and to combine it with the benefit of further communications developments. This should enable a Fault Level value with a high confidence rating to be produced on demand. WPD have identified a real network environment in which they aim to trial active fault level-based control of a Distributed Generation connection.

Stage one of this project involved laboratory trails comparing the predicted fault level with the actual measured peak current seen in response to a bolted fault. These trials were outstandingly successful, the results showing that the FLM predictions were between 2.5 and 5% of the current measured by lab instrumentation – an error margin felt very hard to improve upon as noise on the network and sensor deficiencies will always produce some degree of uncertainty.

All these trials show that the FLM technique is not only accurate, but also that this precision can be repeated in different network situations. Outram Research Ltd is currently in talks with other DNOs to get the Outram FLM deployed in a number of further sites. After reinforcing their findings with more trials, Outram looks forward to offering the FLM to the wider market and is now accepting expressions of interest.

Android user interface for power analysis

Outram Research's Bluetooth®-enabled power quality range now interacts with Android devices enabling flexible remote control using the latest tablets and mobile phones. Power engineers can now control the entire range of Outram’s power quality analysers with one application running on either an Android or Windows device.

Power quality analysers are often deployed in electrical cabinets or other difficult to reach locations, making it difficult for engineers to read a display on the instrument. Using a remote solution rather than a fragile integrated display eliminates problems of analyser location, permits a more robust product and allows for a more comprehensive, graphically superior user interface.

In addition to viewing information such as phasor diagrams to validate correct set up and operation, engineers can remotely access real time power quality data from the analyser. This wireless communication, via PMScreen, allows engineers to program the analyser on site, take snapshots of live data for reporting and check adherence to the EN50160 standard. Engineers can also view current, voltage, power, power factor and flicker, access harmonic data, and in the PM7000 this capability extends to over 500 general parameters. Detailed information is presented on events such as sags (dips), surges and interruptions in power as well as, in the PM7000, ranked waveforms, transients, interharmonics, ITIC Curves and 3D bar graphs.

“We wanted to offer our customers the opportunity to take advantage of the latest technology. Tablets and mobile devices are now prevalent in the workplace and are becoming an integral part of modern business and engineering workflow. Users can remotely control their power quality equipment without disturbing or needing access to the installation, eliminating the need to take time unlocking and locking cabinets or climbing back up the pole. It could mean not entering the building at all so avoiding drawn out entry or safety procedures,” said John Outram, Managing Director of Outram Research.

“Outram has harnessed the impressive processing power of today’s portable devices enhancing the user experience with the introduction of a bigger screen, better graphics and the opportunity to email snapshots of live data.”

Outram Research customers can select from a range of tablets and mobile devices to interact with their Bluetooth-enabled equipment. A Samsung Galaxy tablet is currently provided as standard on the market-leading PM7000, the industry’s Cat IV 600V Phase A-powered power quality analyser, and is available as an option on all other Outram analysers, including the 3-phase PM3000, single-phase PM1000 and the split-phase PM2000 that is designed specifically to troubleshoot residential power quality problems in the USA.

Power quality analyser for memory extension

New PM3000 Extended Memory Capabilities from Outram Research Speed Resolution of Power Quality Problems

Outram Research has developed four new memory extensions available for its PM3000 Analysers. The PM3000 is now available with a choice of 8MB, 16MB, 32MB or 64MB integrated memory. The new extended memory options offer larger memory capacities than the standard PM3000, which ships with 1MB, allowing more detail to be recorded and therefore made available to the user over longer recording periods. The PM3000s with larger memory will in turn offer enhanced profiles of disturbances such as dips, sags, surges and overall harmonic levels, whilst also providing better resolution of phenomena such as Instantaneous Flicker Sensation.

The new extended memory options enhance the capabilities of Outram’s renowned Single Cycle Adaptive Store™ which eliminates the need to set trigger levels when recording power quality parameters such as voltage, current, harmonics, flicker, unbalance, power factor etc. Adaptive Store intelligently chooses when to record in detail, down to a single cycle, using a complex predictive algorithm, without the need to set thresholds. This makes configuration of the unit and analysis of the data much faster and simpler than with other loggers. With larger memory capacities, potentially problematic occurrences can be recorded in more detail for longer, across 16 channels simultaneously, with the 64MB version able to record and store data down to single cycle detail for up to 2 months at a time.


“Power quality engineers are recording over longer timescales,” said John Outram, managing director of Outram Research. “A seven day period used to be typical, but today recording periods are often 14 days or more, which requires larger capacity power quality analysers to record all observed disturbances in the same detail.”

A key benefit of the increased memory is the ability to observe the relationships between Voltage and Current RMS in more detail, enabling power quality engineers and consultants to determine if problems are caused upstream or downstream from the point of measurement. It can then be determined if it is the electricity supplier or the installation that is the cause of the issue.


“The new memory extensions in the PM3000 analysers enable engineers to identify and resolve problems in less time,” continued John Outram. “The combination of our Single Cycle Adaptive Store™ technology with larger memory capacity makes troubleshooting
3-phase power quality issues quick and easy in any commercial, industrial or power distribution situation.”

PM3000 Power Quality Analysers with the new 8MB, 16MB, 32MB and 64MB memory extensions are available today from Outram Research and its distributors. Current PM3000 users can also take advantage of the new capabilities as most existing PM3000 analysers can be upgraded to the larger memory capacities.

Package to power quality measurement in just 15 minutes!

Outram Research has launched its new PM7000 kit, to enable package to power quality measurement in just 15 minutes. The kit includes new guides that allow systems to be configured and connected more quickly and easily than before: it takes less than 15 minutes from unpacking the analyser to starting to log real data. It enables power engineers to set up their power quality analyser and begin recording 470 general parameters and up to 32 detailed channels of power quality data, including transient waveforms, in less time than was previously possible.

Power analysers can be configured in several different ways, and getting the correct physical set up of leads and software can be difficult. The new Outram PM7000 Hook-Up Checklist and Guide to Factory Configurations help engineers set up the analyser in less time, whilst also helping to prevent configuration errors. Vector diagrams in the checklist explain how to interpret the readings from the analyser, whilst an LED “traffic light” system gives clear indication that the system has been set up correctly.


“Power engineers are very busy people who can’t afford to spend large amounts of time setting up and configuring analysers,” said John Outram, managing director of Outram Research. “By shipping direct to site, and cutting the time from receiving the package to recording data to less than 15 minutes, we free them to concentrate on the higher-value tasks of identifying and resolving the cause of power quality problems.”

Outram power analysers have always offered some of the shortest set-up times due to their Single Cycle Adaptive Store™ technology, which eliminates the need to set trigger levels. This unique storage regime records down to a single cycle those disturbances that are most likely to show the cause of power quality issues, no matter how long the recording period. In addition, the powerful auto-ranking waveform capture feature automatically stores the waveforms of the greatest disturbances or abnormalities during a recording, and presents only the most severe, making identification of the periods when power quality problems have occurred fast and straightforward.

The Outram power analyser kits contain everything required, including fully-fused voltage leads and Rogowski coils accurate to 1%, to record power quality data and detect disturbances that could indicate the cause of power quality problems. The systems also ship with a netbook or windows compatible mobile phone, which has been configured to communicate with the analyser “straight out of the bag”.

The Outram PM7000 power quality analyser is now supplied in these “ready-to-go” kits and can be ordered with a mobile phone or netbook that is factory configured for immediate communication with the analyser.

Fast power quality problem resolution

Outram Research tells us that its PM7000 power quality analyser helped Southern Company, the premier energy company serving the Southeast USA, to resolve a power quality problem quickly and easily. Power quality problems are notoriously difficult to troubleshoot often occurring intermittently and as a result of a wide range of causes.

Southern Company responded to complaints of flickering lights from a residential customer and her concerns of a faulty electrical installation by installing a standard meter socket voltage recorder. This, however, failed to find anything out of the ordinary so the problem was referred to the Company’s specialist Power Quality group. A senior engineer deployed an Outram Research PM7000 power quality analyser that uses the patented Single Cycle Adaptive Store data management technique to search for and record those waveforms most likely to be the cause of power quality problems.

The PM7000 allowed the engineer to zoom in on the exact times that the flickering occurred, and to identify sags in the voltage that were followed surprisingly by very short periods of oscillation to even lower voltages. This detail illuminated the very small anomalies in an otherwise normal looking recording that enabled him to identify the cause as a nearby sewage treatment plant. This plant was using a solid state starter to apply waves of reverse power to gradually bring to a stop a large pump motor, preventing water hammer – pressure surges that can cause noise, vibration and even failure of pipes - when they closed a valve. Once the problem was identified, the resident was assured that her electrical installations were safe and corrective action could be taken.


“A conventional recorder would have to be set on cycle store to get this level of detail, and we only set them to cycle store when we already suspect something like this is happening,” Patrick Coleman of Southern Company told Outram. “Starting from scratch, we would have spent weeks zeroing in on something like this with a conventional recorder, but the PM7000 caught it on the first try, with no special setup.”

“Even other recorders meeting the full rigour of IEC61000-4-30 would not have captured this detail,” commented John Outram. “The standard requires you to record over 200msecs and the voltage excursions seen here are much too small to constitute a dip. The evaluation method fundamental to IEC61000-4-30 would unfortunately have filtered out and eliminated the very effect you need to see.”

Adaptive Store is the patented technology from Outram Research that automatically records the chosen parameters in great detail and at high sampling rates when anomalies and deviations from the predicted trend occur. By automatically adjusting the thresholds distinguishing the anomalies from the trend as signal dynamics change or the available memory becomes full, the PM7000 ensures that less significant phenomena can be summarised and greater detail recorded for abnormal behaviour. It can record this level of detail over long periods, indefinitely if set in ‘First In First Out’ mode and the recording sessions are automatically downloaded to a USB stick. Using Adaptive Store is considerably faster and simpler than setting and adjusting trigger levels as required by other power quality monitors: a process that can lead to an operator taking weeks to ‘zero in’ on the problem as the Southern Company Engineer observed, as well as needing to wade through much unnecessary data.

“Adaptive Store is a technology we developed to reduce the time and cost associated with troubleshooting power quality problems,” explained John. “By taking quick action using the PM7000, Southern Company was able to identify the cause and resolve the problem in a short time frame, minimising the inconvenience to its customer.”

The PM7000 is widely used by companies wanting to troubleshoot, identify and resolve power quality problems quickly and efficiently.

Power quality analysis extension

Outram Research has announced a new revision of firmware for their PM7000 power quality analyser, Waveform Capture Extension, which allows capture of long-duration transients and waveform events. The new feature is designed to help engineers troubleshoot long-duration problems and to see the consequential impact of disturbances.

Whilst most transients and waveform events are over in less than three or four cycles, occasionally it is useful to capture longer periods. Examples include monitoring the network’s recovery from sag after reclosures, or to view the reaction of downstream control systems such as wind turbine control.

The Waveform Capture Extension allows for selective extension of the capture window beyond the 160ms that was previously possible, enabling recording for up to 60 seconds. Extensions of the different capture triggers can be set individually, enabling complete control over the monitoring of the disturbances that are recorded for the longer period. The PM7000 can automatically terminate recording when the Sag/Surge is over to optimise the use of the available storage.

Waveforms recorded by the Extended Waveform Capture feature can be displayed and analysed in Pronto, Outram’s logger control software that will also manage the data, produce comprehensive graphs, generate reports and export the waveform sample data to other desktop software packages such as Microsoft Excel.

The new firmware and Extended Waveform Capture feature are fully backwards-compatible, allowing previously saved configurations to be used without modification. Furthermore new configurations can be loaded into a PM7000 with older firmware, with the settings for Extended Waveform Capture ignored if the feature is not available.

The new Extended Waveform Capture feature is now provided as standard across the family of Outram Ranger PM7000 power analysers. New firmware to upgrade existing analysers is available on request.

Research to improve electrical grid planning

Outram Research is conducting a research project with ScottishPower (Energy Networks) that aims to provide new insights into the characteristics of the electricity supply grid, enabling more accurate planning of capacity and upgrades. The research project uses a new technique developed by Outram to measure fault current, the maximum current that can flow in the event of a fault.

Fault current, also known as short-circuit current, is a critical factor for network planning. Objects on the grid must be capable of withstanding the maximum fault current, and components such as breakers must have sufficient rating to isolate the fault safely, allowing the rest of the system to continue functioning.

Determining fault current is a major challenge for planners at electricity utilities as the grid becomes increasingly complex. Motors and other inductive loads can deliver energy back to the grid in the event of a fault, whilst distributed generation of power from renewable sources such as solar power means that parts of the grid may change dynamically from consuming power to supplying energy at different times of the day or week.

Geoff Murphy, lead development engineer with ScottishPower Energy Networks, commented, “With increased dynamics within the electricity network, measuring the capacity and capability of the system is vital to enable the connection of new types of generation and loads. Outram Research offer a novel and efficient way of calculating fault currents to enable us to plan and design the system more effectively and avoid unnecessary expenditure.”

Existing methods of measuring fault current are limited, and can only provide approximate values after a long period of measurement, which may last several weeks. The new patent pending technique calculates fault current accurately and quickly, monitoring parameters without affecting the network or users consuming power. Utility companies can also use the technique to determine how fault current changes over time: for example as different loads are connected and disconnected over the course of a day or week.

“We have already demonstrated the effectiveness of this new technique in the laboratory,” commented John Outram, Managing Director of Outram Research. “Our partnership with ScottishPower will allow us to assess the effectiveness and accuracy of the algorithms and Outram hardware when used to monitor current in the field.”

The research project is already underway, with results expected in the fourth quarter of 2011.

Power quality

Outram Research's PM7000 now offers additional features to help identify and resolve power quality problems caused by the increasing use of energy-efficient appliances and renewable power sources. Harmonic distortion can become a significant problem, as more and more mains-connected devices use high-efficiency switching power supplies or inverter-type power sources and power is increasingly supplied from renewable sources that require a DC to AC conversion.

Switching power supplies, which are used in products such as variable frequency motor drives (VFDs), IT equipment, home entertainment systems and LED lighting tend to draw power through current spikes at the peak of the mains cycle. Low-energy compact fluorescent light bulbs (CFLs) also exhibit the same behaviour. Drawing current at the peaks causes harmonic distortion which results in power being wasted in motors and transformers. It can also cause increased noise and wear on bearings and in extreme circumstances the equipment can fail due to overheating.

Renewable energy sources such as solar cells may require conversion of DC power to AC. If the output AC waveform is an imperfect sine wave, this harmonic distortion can have a similar effect.

The Outram Ranger PM7000 is the first power quality analyser to offer analysis of the phase difference between the harmonic voltage and current, giving additional detailed information about the source of distortion of the mains waveform. Modern switching power supplies often exhibit problems at high frequencies, and so the PM7000 offers one of the industry’s highest sampling rates, recording up to the 50th or 120th harmonic.


“Visibility is critical to help engineers solve the increasing problem of harmonic distortion of the mains waveform,” said John Outram, Managing Director of Outram Research. “By providing information on the phase difference between current and voltage up to the 120th harmonic we help engineers to identify and resolve problems more quickly and efficiently.”

The new harmonic distortion analysis features are now provided as standard across the family of Outram Ranger PM7000 power analysers. New firmware to upgrade existing analysers is available on request.

Faster and easier power quality analysis

Outram Research has launched an enhanced template function in Pronto, their popular analysis and reporting software. The new comprehensive capability provides “two-click graphing”, allowing non-technical users to produce complex graphical analysis of power quality data quickly and easily.

The templates dramatically reduce the time needed to analyse data, without requiring expert knowledge of either power quality or the Pronto software. Users can select the data to be displayed, the colours to be used and can manipulate the as axes, including whether graphs are superimposed or stacked and whether the scales are automatic or fixed.

Templates are managed in a hierarchical directory structure, making selection of the required output intuitive. Furthermore Pronto uses a “traffic light” approach to show which templates can be used with the data set that has been loaded. A green light indicates that all data is present, amber that part of the output can be produced and red indicates that the data set is not compatible with the template. The graphs produced by Pronto can easily be copied into a report produced in other packages, such as Microsoft Word.

Many users can benefit from the new functionality. Some users might have specific requirements – for example monitoring specific harmonics, whilst consultants might want to produce consistent reports, and other engineers need to monitor the same parameters over a long period of time, which requires consistent presentation of the data.


“Pronto offers the most comprehensive graphing features of any power quality analysis package,” said John Outram, Managing Director of Outram Research. “As our products become more powerful and flexible, producing consistent analysis may be challenging for operators who are not power quality specialists. The new templating functionality ensures the user gets exactly the graph he wants with just a couple of clicks, an approach that we plan to introduce for the other output functions offered by our software.”

Pronto offers many advantages over generic packages such as spreadsheets. In addition to providing the new graph templating functionality, it allows easy access to all the data collected by the analyser. This software can also manipulate and graph millions of data points, something that is not possible with standard spreadsheet packages.