| Abstract |
This paper presents modelling, simulation and experimental verification of a permanent magnet synchronous motor drive (PMSM) with bi-directional power transfer capability. A permanent magnet synchronous machine connected to a dc voltage link by a PWM voltage type converter composes the system. A second PWM voltage type converter connects this dc link to the ac network. The control objectives of the PWM voltage converter connected to the ac mains are to ensure a unity power factor, and to maintain the DC voltage in a constant value. The unity power factor is achieved by setting the phase current references with the same waveform as the mains phase voltages, and a proportional-integral controller, acting in the magnitude of the current references, controls the DC voltage. In the PWM voltage converter connected to the PMSM, the quadrature Park's current component is controlled, and a null value for the direct current component is imposed. By this way, the machine electromagnetic torque control is achieved, and decoupling between flux and torque is obtained. From the AC mains viewpoint, near sinusoidal input current waveforms are obtained. Also load power variations do not produce reactive power variations in the converter AC side. |
