Series capacitor bank no-dead-zone protection method

The invention discloses a series capacitor bank no-dead-zone protection method. A working current mutual inductor is connected with output ends of two parallel branches. The working current mutual inductor collects a load current and transmits the load current to a controller. A ratio between an unbalanced current and the load current is defined as a bridge difference ratio. When the bridge difference ratio obtained through calculation of the controller exceeds a bridge difference ratio prewarning value, the controller gives an alarm. According to the series capacitor bank no-dead-zone protection method, a 'bridge difference ratio' protection formed by adoption of the ratio between the unbalanced current and the load current is used as a main protection of a series capacitor bank, motion dead zones are eliminated and the protection motion dead zones of the series capacitor bank are controlled to be less than 3% under any working conditions. Failure alarming dead zones of capacity of a single bridge arm capacitor can be controlled to be about 5% under any working conditions. The protection sensitivity is high and the series capacitor bank no-dead-zone protection method is not affected by the load current.