Computerized simulation validation for full-scale testing

A method of correctively adjusting a test configuration of a full-scale distribution network single phase-to-ground fault test, implemented by a real-time digital simulator (RTDS) comprising a processor implemented by at least one of a digital signal processor (DSP), a field-programmable gate array (FPGA), or a programmable logic array (PLA), and a communication interface coupled to measurement devices installed at a full-scale distribution network single phase-to-ground fault test site, the method comprising:

• obtaining, by the RTDS from Common Format for Transient Data Exchange (COMTRADE) waveform files generated by the measurement devices, recorded waveforms and external characteristic parameters of field testing of the full-scale distribution network single phase-to-ground fault test;
• obtaining, by the RTDS using Fast Fourier Transform (FFT)-based signal-processing algorithms, internal quantities of the field testing based on the recorded waveforms of the field testing;
• building, by the RTDS, a real-time simulation model of the distribution network that comprises an equivalent power source, a step-down transformer, a grounding transformer, an arc suppression coil, a distribution line, a circuit load, and a fault trigger control module, by:
• adjusting parameters of the equivalent power source and the step-down transformer to maintain conformance with pre-fault phase voltage and pre-fault phase current values obtained from the recorded waveforms of the field testing, and adjusting a magnitude of the circuit load to maintain conformance with a pre-fault phase current value;
• adjusting parameters of the distribution line to maintain conformance between a system capacitive current of the simulation model and a system capacitive current value of the external characteristic parameters;
• controlling a fault trigger angle of the simulation model to conform with a fault trigger angle obtained from the recorded waveforms of the field testing;
• and
• iteratively emulating occurrence of a ground fault in the simulation model and recording simulated waveforms, computing a waveform conformance metric between the simulated waveforms and the recorded waveforms of the field testing, and adjusting at least one of a fault point location and a ground fault resistance value of the simulation model based on the waveform conformance metric, until the waveform conformance metric satisfies a predefined conformance threshold, thereby achieving closed-loop calibration of the simulation model to the measured field-test behavior;
• obtaining, by the RTDS, recorded waveforms of simulation testing based on the external characteristic parameters by inputting the external characteristic parameters into a real-time simulation model of the distribution network that comprises an equivalent power source, a step- down transformer, a grounding transformer, an arc suppression coil, a distribution line, a circuit load, and a fault trigger control module, and executing the simulation model in real time;
• obtaining, by the RTDS using the FFT-based signal-processing algorithms, internal quantities of the simulation testing based on the recorded waveforms of the simulation testing;
• determining, by the RTDS, whether a field-testing result of the full-scale distribution network single phase-to-ground fault test is reproducible based on a relationship between the internal quantities of the field testing and the internal quantities of the simulation testing that includes verifying conformance of at least one unconventional quantity selected from negative-sequence current, line dielectric loss, phase current change, and multi-harmonic zero-sequence admittance;
• validating the field testing of the full-scale distribution network single phase-to-ground fault test in case of the field-testing result being not reproducible by:
• outputting a validation result indicating whether the field test setup satisfies a predefined normative criterion for full-scale ground fault testing;
• identifying at least one external characteristic parameter that fails to satisfy the predefined normative criterion;
• and
• correctively adjusting at least one physical device selected from the group consisting of a circuit load, an arc suppression coil, a grounding transformer, or a fault trigger control module of the full-scale distribution network single phase-to-ground fault test site based on the identified external characteristic parameter,
• wherein the external characteristic parameters comprise system capacitive current value, harmonic content, load condition, ground fault resistance value, and ground fault trigger angle,
• wherein the internal quantities comprise three dimensions of steady-state quantities, transient quantities, and unconventional quantities,
• wherein the unconventional quantities comprise negative-sequence current, line dielectric loss, phase current change, and multi-harmonic zero-sequence admittance.