Series connection fault arc pre-warning system and detection method thereof

The invention provides a series connection fault arc pre-warning system. The series connection fault arc pre-warning system comprises a power circuit, a current transformer, a current sensing circuit, a signal processing circuit, a voltage zero balancing comparison circuit, a microprocessor and a fault output circuit. The current transformer, the current sensing circuit, the signal processing circuit and the microprocessor are successively connected. The voltage zero balancing comparison circuit and the fault output circuit are respectively connected with the microprocessor. The current transformer collects a current signal in a power network to transform the current signal into a voltage signal through the current sensing circuit to input to the microprocessor through the signal processing circuit, and the voltage zero balancing comparison circuit outputs a voltage zero balancing pulse signal to the microprocessor. The invention further provides a series connection arc fault detection method. The series conn