Research on Measurement Method for Capacitive Current of Distribution Network Based on Signal Injection

During the operation of large capacity distribution network, it is necessary to measure the capacitive current to match the corresponding arc suppression coil. In order to solve the problem that the capacitive current cannot be measured in the distribution network system whose neutral point is grounded by arc suppression coil, this paper proposes a method to measure the parameters of the distribution network by injecting four different frequency signals from the neutral. This method can measure the distributed capacitance of distribution network when the arc suppression coil is running online. It can automatically detect the operation state of arc suppression coil in distribution network and select different equivalent models for calculation. Theoretical analysis and experiments show that the method has strong adaptability, simple calculation and high measurement accuracy.