Document Type : Research article

Authors

1 Department of Electrical Engineering, Faculty of Engineering, Shahid Chamran University of Ahvaz, Ahvaz 61357-85311, Iran

2 Department of Electrical Engineering, Faculty of Engineering, Arak University, Arak 38156-8-8349, Iran

3 Department of Electrical Engineering, Firouzabad Higher Education Center, Shiraz University of Technology, Shiraz, Iran

4 Department of Electrical Engineering, Faculty of Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran

Abstract

The utilization of distributed generation (DG) in today's power systems has led to the emergence of the concept of microgrids, in addition to changing the mode of generating and supplying the energy required for network electrical loads. When a microgrid operates in the island mode, energy generation sources are responsible for controlling the microgrid’s voltage and frequency. As the microgrid frequency is proportional to the amount of power generated by the DG, the microgrid requires a precise power-sharing strategy. Considering that DGs do not usually have stable output power despite the importance of power stability, the present paper addresses the voltage and frequency control of an islanded microgrid by considering the power generation uncertainties caused by disturbances and the varying power output of DGs. Given that the disturbance on the first DG's input current is 0.2 A, which is approximately 2.2% of the steady-state value, a simulation was performed, and it was observed that the maximum voltage variation of each bus in the worst case was 0.59% for the first bus and 0.53% for the second bus, which means that the controller could control the voltage and frequency values within the permissible range. If the controller is not used, the change in the frequency of each bus will be 10 times, and the voltage change will be 5 times as great as that of the case the controller is used.

Highlights

  • Design a controller for voltage and frequency control of the islanded microgrid
  • Considering the dynamics of each DG with electronic power converters
  • Considering the disturbance in input power of DGs to eliminate this power input disturbance
  • Implementing the necessary changes in power electronic switching to reach the control objectives

Keywords

Main Subjects