A Comparative Study of The PI Controller to The Hysteresis Controller for Voltage and Current Control In Inverter-Based Microgrids

The control of voltage and current in inverter-based microgrids is very critical. A good controller which is capable of providing a high-performance response to load disturbance should be implemented for current control in grid-connected microgrids and voltage and current control in islanded microgrids respectively. This study employs inverter-based microgrids that are connected in grid-connection and islanded modes respectively. To control the voltage and current, a proportional-integral controller for the three-phase voltage source inverters has been proposed. The robustness of the proposed controller has been achieved by including the inner current control loop that has a smoothing capacitor for reducing the transients and improving performance. The controller has been tested in grid connection and also in islanded modes of operation. The designed inner current control loop provides good response in abnormal and unbalanced load conditions. The proposed proportional-integral controller presents superior performance during abnormal and unbalanced load conditions in the system. The control method has been simulated in Matlab/Simulink 2018a and the simulated results have been analyzed and compared to the hysteresis current controller.