Research On Closing-over-voltage Caused By Wind Farms Connecting To Grid

The short-circuit fault of contact frequently happens on power supply side of the main circuit breaker of690V when Wind Farms Duerbote goes on the box-transformer closing operation with load switch of35kV. To study the causes of the above result, Inner Mongolia Electric Power Research Institute carries out tests on related equipments of Wind Farms Duerbote box-transformer, switching over-voltage and inrush current. Through a series of test and analysis, the max close-bouncing over-voltage is16.4times, thus the paper comes to a conclusion that serious Close-bouncing over-voltage is the key reason for the insulation breakdown of power supply side of the main circuit breaker. The program of installing absorbing capacitors is proposed and field-proven results are obvious. The max close-bouncing over-voltage reduces to2times.The paper simulate the over-voltage with MATLAB/SIMULINK, obtains similar conclusions to field tests, that is, the max close-bouncing over-voltage is18.5times before protection and3.01times after protection, verifies the correctness of the program adopted and are valuable for the research of the same kind of problems.