Document Type : Research article

Authors

• Saeed Aminzadeh ^{1, 2}
• Mehrdad Tarafdar Hagh ^{1, 3}
• Heresh Seyedi ¹

¹ Faculty of Electrical and Computer Engineering, University of Tabriz, 29 Bahman Blvd, Tabriz 51666-16471, Iran

² Engineering Faculty, Islamic Azad University, Ravansar, Kermanshah, Iran

³ Engineering Faculty, Near East University, 99138 Nicosia, North Cyprus, Mersin 10, Turkey

Abstract

This paper uses the coordination between the reactive power of a solid oxide fuel cell (SOFC) and a battery to control the frequency within an islanded microgrid. By this coordination, the microgrid frequency regulation becomes faster and better during contingencies. Moreover, the energy storage capacity, which is usually required for the frequency control of islanded microgrids, has significantly been reduced. Furthermore, there will be no need to consider reserve capacity in renewable sources for frequency control. Therefore, renewable energy sources can be operated at their maximum power point. Also, this paper introduces a new frequency-reactive power control concept and a related coefficient that shows the degree of dependence of the microgrid frequency on the injected reactive power changes at each bus. This coefficient determines the priority of buses for the installation of reactive power control devices to control the frequency of the microgrid. Simulation studies have been performed in the MATLAB/Simulink environment. The results show the applicability and accuracy of the proposed coefficient and demonstrate the effectiveness of the coordinated control of reactive power between the SOFC and the battery for frequency control.

Highlights

• The idea of manipulating the active power consumption of loads by voltage control has been proposed to improve the performance of conventional frequency control systems.
• The CBEMA curve allows short duration voltage drops in the system. This permission has been exploited to deliberately decrease the voltage magnitudes of selected buses for a very short period of time.
• The coordinated reactive power management system between the solid oxide fuel cell (SOFC) and the battery has been proposed to be added to the conventional frequency control system to improve its performance.
• The proposed frequency-reactive power factor (FQ) can be used to determine the sensitivity of microgrid frequency to the reactive power change in each bus. FQ is used to determine the appropriate buses for installing SOFC.

Keywords

• Microgrid frequency control
• Solid oxide fuel cell (SOFC)
• Coordinated control of reactive power
• Frequency-reactive power coefficient

Main Subjects

• Power