Control Strategies Of Dual Three-Level Inverters For Open-end Winding Synchronous Motor

Motor control system has been widely used in the industrial production field to save energy. Currently, the motor control system is constantly development toward high-voltage, large capacity and high dynamic performance. The open-end winding topology can provide higher output voltage and more voltage level. Besides these advantages, it has a mature and simple circuit structure which can improve the system stability. Therefore, this circuit topology has broad application prospects in the field of high-voltage motor drive. The paper mainly analyzes the circuit structure, the voltage vector space, SVPWM control algorithm of dual three-level inverter power supplied open-end winding topology. The main contents of this paper are shown as follows:(1) The development process and circuit characteristics of dual inverters power supplied open-end winding topology are briefly introduced. After analyze the research status of this topology, this thesis choose to combine diode-clamped three-level inverter with open-end winding circuit structure as the research direction.(2) The thesis detailed analysis the diode-clamped three-level inverter topology’s features, working principle and its voltage vector space. After that, the paper establish the mathematical model of dual three-level inverter system and using the superposition method to obtain the system space vector diagram.(3) The thesis detailed analysis the SVPWM algorithm of diode-clamped three-level inverter. Propose a feasible implementation scheme of SVPWM algorithm for dual three-level system and verify it by simulation.(4) A pulse transmission method that can solve the neutral-point voltage balance, power balance, pulse delay and other issues was proposed in this thesis, and verify this method by simulation.(5) Finally, the thesis build a25kW experimental platform to test the theory.