A Novel Copper Layer-Based Field-to-Trace Coupling Model and EMS Evaluation Method for DSP-Based Control Circuit in MMC-HVDC System

Underlying control circuit failure problems, especially control signal output failure problems, widely occur in high-voltage large-current modular multilevel converter (MMC) valve towers. The failure mechanism for the digital signal processor (DSP)-based control circuit is studied in this article. This study is based on the combination of low-voltage-level integrated circuit (IC) immunity model and a new perspective on the field-to-trace coupling effect. A novel copper-layer-based field-to-trace coupling model which combines the power system and digital control circuit in the MMC valve tower is proposed. Therefore, the specific electromagnetic interference (EMI) value conducted into the IC can be calculated. Then a new DSP IC electromagnetic sensitivity (EMS) evaluation method is proposed, which can be a guideline in industrial applications. To show the validity and accuracy of the field-to-trace coupling model, an indirect laboratory experiment is designed, then a situation is considered in this article, and the results are compared with PSpice circuit simulations, which show acceptable relative errors. Moreover, based on the situation considered above, one application example of the novel evaluation method is described in detail.