Physical-Simulation-Based Relay Protection Training System For Distribution Network

In order to improve the professional ability of relay protection practitioners in distribution network,a relay protection training system which is suitable for distribution network is designed in this paper.The training system mainly consists of two modules:physical simulation platform and setting training software.Trainees can learn the theory and practice protection setting in the setting training software,and then use the physical simulation platform to verify the action of the relay protection by fault experiment.It makes trainees get the relay protection configuration and setting skills directly.The physical simulation platform of distribution network is based on the similarity principle to establish a model system simulating actual distribution network.According to the equivalent principle of impedance per-unit value consistency,the simulation ratio is derived by using impedance and voltage as independent parameters.The independent designed transformers are used to simulate main transformer of substation.On the basis of ensuring the characteristic and amplitude of the fault current,the system adopts the simplified π-line equivalent model.By the PLC control contactor switches to achieve the simulation of circuit breaker.An external fault simulator is adopted for fault simulation and several relay protection devices are used to realize the relay protection function.Besides,monitoring software based on SCADA system is designed for the operators.The protection configuration and setting training software of distribution network is a graphical operating system developed on Delphi platform.It achieves training operations,theory training,theory test and other functions.It is divided into trainer platform and trainee platform according to different authorities.The trainer platform has management functions in addition.The training operation provides trainees distribution network drawing and topology analysis,automatic fault calculation,protection configuration and setting,and finally trainees can get setting result list.Theory training offers trainees studying on line.A self-built test library is built in the theory test module for generating examination papers for trainees to practice and test.Trainers can check the achievement of trainees by the practice and exam.At the end of this paper,in order to verify the efficiency and applicability of the whole training system,results getting from the physical simulation platform,the setting training software and the PSCAD/EMTDC simulation platform are compared on waveforms,short-circuit current and protection actions separately.It shows that the training system can be successfully applied in the relay protection training for distribution network.