IVPower AFA in a nutshell
As an automatic fault analysis (AFA) system, IVPower is designed to complement power system protection and control systems by providing a detailed view on power system disturbances.
IVPower uses disturbance recordings and substation automation event logs as the main sources of data for this purpose.
Analog signals of the disturbance recordings are used to perform automatic fault detection and analysis at power system level, providing, notably, optimum reactance-based fault location based on measurements from one, two, or more terminals of power lines or cables.
Status changes of process signals in the event logs can complement the binary signals of the disturbance recordings and increase the observability of the process; altogether, and combined to the accurate fault location results, they help with the analysis of the behaviour of protection relays and circuit breakers.
In near real time, i.e. within a few minutes after a fault, IVPower provides time-sensitive and crucial information needed for remedial actions to operators by email or text message.
The same software is also a very useful tool for post-mortem analysis by the experts and it can export the results of data analysis to other information systems, such as a database used for asset life cycle management.
Fast, accurate and reliable fault location
IVPower uses fault records in COMTRADE format and provides reactance-based fault location from one, two, or more terminals of power lines or cables.
Our exclusive fault location algorithm supports:
- Unlimited number of COMTRADE records
- Estimate of the tolerance
- Indication of closest tower and geographical position
- Automatic selection of voltage channels
- Compensation of mutual coupling
- Consideration of shunt reactors and parallel cable sections
As a result, most high-current short circuits can be located with an accuracy better than 5% of the line length. Independent calculation based on traveling-waves fault locators can be integrated, if such devices are installed.
Each fault location event is given a graphical representation of the fault on the line. This graphic displays the whole faulted line, with a red rectangular region that represents the possible fault location, taking into account the computed tolerance. Line feeders associated with recording devices are represented with flags. A tooltip indicates the station and the feeder labels:
Manual reclosing suggestion
To help the dispatcher in the situation where one or several lines have been tripped (no autoreclosing or unsuccessful autoreclosing) and when it is important to decide quickly which line should be manually reclosed first.
Rules for manual reclosing vary from one utility to the other depending on the infrastructure, regulation and operational practice. But we also offer some additional functions to assist decision making:
- Indicate whether a lightning strike has (likely) hit the line, by correlation with meteorological data.
- Detect secondary arc in case of single-pole tripping, determine the time of secondary arc extinction and provide reclosing suggestion to the operator if it is reasonable to think that such an attempt has a fair chance of being successful.
- Analyze the voltage-current pattern of the fault, which in some cases reveals the possible fault cause (burning vegetation…). A pattern corresponding to a free burning arc in the air may characterize a transient fault.
Lightning strike correlation
IVPower provides additional insight about the faults: for example, it correlates faults on transmission lines with concurrent lightning strikes within the same area. The automatic conclusion provided by IVPower helps operator decision to reclose the line in case of unsuccessful automatic reclosing.
Sequence of fault events
The sequence of events is presented in a relative time scale the origin of which is the time of fault inception.
The initial representation of the sequence of events only considers the information related to analog time series (voltages and currents). Some filters enable to also display the binary information (protection pick-ups and trips, etc).
Furthermore, it is also possible to extend the area in order to see what happened at the same time on other lines.
Export of circuit breaker switching events
Spreadsheet files containing identifiers and operational values (feeder name, breaker name, break/make currents, timestamps, …) can be generated and exported.