The application provides a short-circuit
control system and method for a small-current grounding fault
simulation test, and belongs to the technical field of power
system fault
simulation. The
system solves the problem that the control precision and cost of the
initial phase angle of the existing fault
simulation device are difficult to be considered, and the simulation reliability of the transition resistance is low. The
system comprises a main circuit and a
control circuit. The main circuit is provided with a transition resistance circuit and a bidirectional
thyristor in series. The
control circuit comprises a synchronous
transformer, a zero-crossing detection circuit, a single-
chip microcomputer control unit and a
thyristor drive circuit which are sequentially connected by signals. The system
voltage zero-crossing point is locked by the zero-crossing detection. The bidirectional
thyristor is triggered by the single-
chip microcomputer according to the preset fault
initial phase angle and the transition resistance circuit with multiple fixed resistance parallel connections to realize the grounding fault simulation. The application has the advantages of accurate control, low cost and high reliability, and can be widely applied to the power system fault
simulation test and the performance test of the line selection device.