Analysis of EMI Source in the Balanced Inverter with Desynchronization of Gate Signals

This paper presents an analytical model for estimating electromagnetic interference (EMI) generation when a balanced inverter experiences desynchronization of its inverter gate signals. The balanced inverter is a novel topology that can reduce the common-mode emissions significantly when the gate signals are tightly synchronized. However, the impact of non-ideal conditions in the inverter or machine must be carefully investigated. This condition may be attributable to a variety of sources including desynchronization of the gate signals, unbalanced parasitic inductances in the PCB board, or unbalanced impedances in the three-phase machine windings. Wide-bandgap (WBG) power devices are used in this research which exacerbates the common-mode emissions issue due to the high switching frequencies and high dv/dt values made possible by these devices. The presented analytical approach confirms that gate signal desynchronization should be minimized in order to maximize the CM emissions reduction benefits made possible by the balanced inverter.