Research on control and protection of missing firing pulses for valve basic electronics

A control strategy to avoid the malfunction of converter control and protection (CCP) system due to missing firing pulses of valve basic electronics (VBE) is proposed. The core idea of the proposed control strategy consists in the design of algorithm, namely once the pulse missing in the trigger signal, which is transmitted by CCP system via Ethernet links to the gate unit (GU) of the valve, is detected, the VBE does not do anything; based on operational experiences and mathematical statistics, when the missing of four consecutive pulses with duration of 80 ms is detected, according to the proposed control strategy the VBE sends the fail signal to CCP system to ask for the switching. The VBE system adopting the proposed control strategy is applied in the coordinate control experiments of real-time digital simulator, and experiment results show that the proposed control strategy can effectively eliminate the danger caused by existing protection methods and reduce the malfunction probability of CCP system.