5 kW bidirectional grid-connected drive using silicon-carbide switches: Control

This paper presents a controller design for a fully silicon-carbide (SiC) based bidirectional three-phase grid-connected PWM drive. For drive applications, controller must be robust and fast to be able to provide power flow in both directions. In this paper, proportional resonance (PR) current controller in the stationary reference frame is used. Furthermore the influence of feedforward compensation for stability of the rectifier is studied. Two different experiments are conducted to observe the stability of the converter. In the first experiment, a 5 kW bidirectional SiC based three-phase rectifier with switching frequency of 45 kHz will be tested. The test is done by connecting it to a grid simulator and the load is a resistive load. In the second test the rectifier will be connected to the grid via an auto-transformer and load is a 7.5kW SiC based drive which is connected to a permanent magnet motor. Different tests will be conducted to evaluate the performance of the controllers in both generative and regenerative mode. It is shown that the controller can provide a good dynamic response to load changes for both direction of power flow.