Fuzzy Based Control of Grid-Connected Photovoltaic System for Enhancing System Inertial Response

This paper proposes a fuzzy-based control strategy for grid connected solar photovoltaic (PV) system, enabling it to participate in frequency control without energy storage. The Proposed control enables the PV to participate in frequency regulation during low inertia period by shifting its operating point below MPP. An IEEE 14-bus system is considered as study case system. The bus system has been extended to a more realistic network by incorporating non-reheat thermal units, hydro units, PV units and local loads and is also considered in various non-linearity of generating units such as Generation Rate Constraint (GRC), Governor Dead Band (GDB) and delay in Area Control Error (ACE) signal. For the fuzzy controller, the frequency deviation and varying system inertia are used as an input. The output command decides the required operating point of PV to provide primary frequency control (PFC). This method is found to be effective in reducing the initial system frequency deviation and rate of change of frequency. A comparison with existing PV control shows that with the use of proposed fuzzy PV control, primary frequency responses have been improved.