Design and experiment of zero-sequence voltage flexible control device for distribution network

The traditional passive arc suppression device can not compensate the active component of single-phase grounding fault current, and its arc suppression effect is limited. A zero-sequence voltage flexible control device was proposed and designed in this paper. It applies DSP+CPLD module to implement the PWM active inverter based on arc suppression technology. Under the normal conditions of network, a specific frequency current signal is injected into network to measure the grounding parameters and calculate the compensation current of grounding fault. And in the single-phase grounding faults conditions, the injection current is generated by the inverter, and injected into the neutral point of network to suppress fault current. The injection current can compensate active component, reactive component and harmonic component of fault current at the same time. Experiment was developed, and results showed that arc suppression effect was obvious and response speed of the device was fast.