Experimental Verification of a Virtual Medium-Voltage High-Speed Synchronous-Motor Drive Test System Based on Two Modular Multilevel DSCC Converters

This paper discusses the experimental verification of a virtual synchronous-motor drive test system. This test system consists of two identical modular multilevel double-star chopper-cell (DSCC) converters characterized by a front-to-front (FTF) connection. One converter acts as an inverter under test, while the other acts as a part of the virtual motor and load. The experimental waveforms obtained from the test system designed and constructed in this paper confirm satisfactory electrical and mechanical dynamics of the virtual three-phase 200-V, 10-kW, two-pole, 18,000-r/min synchronous motor with a virtual quadratic-torque-to-speed load an as a high-speed compressor. The driving performance of the test system shows that the DSCC inverter under test is applicable to high-speed synchronous motor drives.