Simulation of Conducted Disturbance Protection for TTM Online Monitoring Unit Port

Based on the requirements of high-voltage direct current transmission projects, the thyristor level monitoring system of the converter valve needs to be installed on-site. The harsh electromagnetic environment in the valve hall places high demands on the electromagnetic compatibility performance of the monitoring device, especially for the protection of the converter valve online monitoring unit against electromagnetic interference. It is urgent to propose a more comprehensive design scheme. Therefore, this article conducts simulation and experimental research on the electromagnetic interference protection of monitoring unit circuit board ports. Firstly, three improved disturbance source circuit models and two electromagnetic protection device models were established. Then, through simulation, the protection performance of the two protection devices against disturbance sources was tested. Finally, the two protection devices were applied to the thyristor trigger and monitor unit (TTM) port of the thyristor trigger monitoring unit for protection design. The effectiveness of the simulation and protection scheme was verified through electromagnetic compatibility tests, and the results showed that adding protective devices to the TTM port can effectively suppress the interference generated by transient pulses through conduction.