Study of Rotor Earth-Fault Protection With Switch Sampling Principle
Xu Xidong Jin Yu Guo Xiaoming (Zhejiang University Hangzhou 310027 China)
Commonly, by opening one switch and closing the other, two group equations are set up to measure rotor earth-fault resistance in the rotor earth-fault protection with switch sampling principle. This paper advances setting up a third group equations by opening both switches. By analyzing the partial derivative of earth-fault resistance versus each sampling current at different earth-fault location and different magnitude of earth-fault resistance, an approach is presented which measure the earth-fault resistance by selecting two proper group equations at different earth-fault location. Experimental results demonstrate that the approach can reduce the influence of sampling current error, especially in low exciting voltage and low earth-fault resistance condition.
【CateGory Index】： TM77