Comprehensive application of signal injection method in protection and control of MV distribution system

In MV distribution system, signals need to be injected regularly or when the single phase-to-ground fault occurs while distributed capacity measurement, fault line selection and fault location techniques based on signal injection are applied. In order to prevent mutual interference of different signals, reduce equipment investment and simplify wiring, the comprehensive application based on signal injection in protection and control of MV distribution system is proposed. In this paper, optimal signal frequency, signal injection mode and signal detection mode which can be shared are chosen by taking carrier based islanding protection as research object and taking the applications of distributed capacity measurement, fault line selection and fault location techniques based on signal injection into comprehensive consideration.