Zero Sequence Injection in Delta-CHB STATCOM: Towards Optimum Silicon Area Through Typical Power IGBT/diode Model

This work quantifies the impact of third harmonic circulating current injection (THCCI) in a Cascaded H-bridge converter in delta configuration (Delta-CHB) for Static Synchronous Compensator (STATCOM) application. The analyses consist of evaluating the impact of THCCI on the silicon area of semiconductor devices. To achieve this objective, this work develops a typical IGBT/Diode model to determine the nominal current of the devices for a given maximum junction temperature. Commercial devices in the voltage classes of 1700 V, 3300 V, 4500 V, and 6500 V were considered, with nominal currents ranging from 150 A to 3600 A. A hybrid approach based on physical-oriented scaling laws and black-box modeling allows to reach a coefficient of determination higher than 79\% for all modeled variables. The results showed an increase of 43.8\% in the active area of the IGBT and 30.87\% in the active area of the diode when the peak cluster current increased by 62\% due to THCCI.