The Research Of DC Signal Injection Method For Single Phase To Ground Faults Location In Distribution Network

In the distribution network fault location, because of the cement pole earth fault and the existence of the wire distribution capacitance makes the C type traveling wave method and the AC signal injection method can not work effectively. DC signal injection method solves the problem of the two methods' blind area. The advantage of it is free from the wire distributing capacitance influence and the weakness is the signal would be difficult to detect. The paper introduces the principle of the method. Then the paper introduces the software and the hardware about the systemic equipment generally. The equipment of DC injection fault location includes DC signal generator source and a corresponding signal detector, DC signal generator source adjusts the voltage through PWM so as to achieve the purpose of output a constant current. The signal detector using magnetometive balance Hall sensor to detect the injected signal, and adopts wireless transmission technology to realize the separation of measurement and display.