Controller Design to Enhance the Performance of a DC Microgrid Containing Solar PV Connected to the Main Grid

Abstract

This paper presents an effective design for a controlled DC microgrid power system that contains a solar photovoltaic (PV) connected to the grid. The main concept of this control system is to improve the operation of distributed generations (DGs) by keeping the balance between the active and reactive power requirements with other system components. The system includes a passive filter to improve the quality of both voltage and current signals. In addition, the maximum power from PV module is extracted by boosting the generated DC voltage to a suitable level. A voltage source inverter (VSI) is utilized to exchange the DC power to the AC grid. VSI controller consists of voltage and current control systems to regulate the output voltage amplitude and frequency as well as to control current waveform and the output power to the grid. This paper studies the effects of temperature and irradiance on the performance of the PV panel. The complete model of the system and its control is designed and implemented using the MATLAB-SIMULINK toolbox. The conventional PI controller is applied to control the system behavior in comparison with PID based Ziegler Nichol controller. The system is subjected to various disturbances such as 3-phase to ground fault and changes in irradiation and temperature. From simulation results, the system performance is enhanced with PID controller based Ziegler Nichol and is suggested to be the optimal controller for this DC microgrid system if it is well tuned.