Maximum Torque per Ampere and Flux-weakening Control of Modular Multilevel Inverter Fed IPM Motor Drive

Abstract

This paper proposes a new interior permanent magnet (IPM) synchronous motor drive based on a three-phase modular multilevel inverter (MMLI). A cascaded maximum torque per ampere (MTPA) and Maximum Torque per Voltage (MTPV) algorithms are designed to control the drive through the field-weakening region to increase the speed beyond the base speed. The control algorithm employs the feedforward optimal current profile and the voltage regulation feedback control. During the constant torque region, the MTPA technique is utilized to produce the the d-q current, whilst the voltage regulation feedback loop is utilized to control the demagnetizing current component in constant power region,accordingly the drive operates in the FW region. The MATLAB/SIMULINK software is utilized toinvestigate the effectiveness of the proposed algorithm.