Multi-input and multi-output control system of PWM converter/inverter-fed IPMSM drive

This paper presents a model of PWM converter and inverter-fed Interior Permanent Magnet Synchronous motor drive system. The IPMSM drive system becomes a multi-input and multi-output control objects, then multi variable control objects such as adjustable speed, unity power factor control and maximum efficiency control can be designed simultaneously. The converter source current components are regulated by vector control (VC) strategy to achieve the desired DC link voltage and unity source power factor. The efficiency can be improved by minimizing the total loss of IPMSM. So, an efficiency optimization algorithm is developed to minimize the total controllable losses of IPMSM. To obtain desired DC link voltage, unity source power factor as well as desired speed of IPMSM with efficiency optimization simultaneously, a state space model for the overall system of IPMSM and converter is derived in a synchronously rotating reference frame. An augmented state space model is developed to design a controller by which the desired control objectives can be achieved. Using the proposed MIMO optimal regulator, desired DC link voltage, unity source power factor as well as desired speed of IPMSM with efficiency optimization can be achieved simultaneously. The effectiveness of the proposed controller is verified by simulations performed by using Matlab/Simulink.