Currently, the detection of the Process layer equipment and circuits between breakers is mainly realized through the control circuit. However, the control circuit cannot detect the status of the tripping-and-closing contacts and straps, leading to the failure of the operation of the process layer equipment. To solve this problem, this paper proposes a ping-pong self-detection based online no-dead-time detection method for the tripping-and-closing circuit. Firstly, the topology structure of the existing tripping-and-closing circuits of protections is improved. A contact of the tripping-and-closing relays and the corresponding optocoupler circuit are added. Then, based on the improved control circuit, the self-detection is completed according to the optocoupler acquisition status by sequentially opening and closing the contact of the tripping-and-closing relays without forming a tripping and closing circuit. The proposed method can improve the reliability of the control circuit, avoiding the failure of the operation of the equipment. The test and on-site pilot validate the effectiveness of the proposed detection method.

optocoupler circuit,,Online Detection,ping-pong self-detection,ping-pong self-detection,on-site pilot