MMC-Based High-Power Motor Emulator for Testing of Electrical Propulsion System

This paper presents a control technique to emulate a high-power synchronous motor using a modular multilevel converter without adding extra physical filter inductors. Motor emulation can be achieved through either fast current control or by adding auxiliary inductors to replicate the current response of the stator inductance in the virtual motor. The first approach requires high switching frequency, which is unsuitable for high-power converters. The second approach demands adjustments to the auxiliary inductance when motor parameters change, limiting the test flexibility of the emulator. To overcome these challenges, this paper proposes an output voltage control that allows the emulator to realize the stator inductance of the virtual motor without hardware modifications or fast current control. The validity of the proposed method is verified through simulation, demonstrating its effectiveness in flexible motor emulation.