Solar Irradiance-based Load Controller for Frequency Regulation under High Intermittency Photovoltaic System

The power output of photovoltaic systems (PV) in Malaysia is highly intermittent due to its location near the equatorial region that is susceptible to many passing clouds. High intermittency of PV power output increases the power mismatches between the power generation and demand. Consequently, it leads to frequency issues such as frequency excursions and a high rate of change of frequency (ROCOF). Several methods have been proposed to mitigate the frequency issues, and demand side management (DSM) has been central due to its lower deployment costs than other methods such as flywheel- and battery-based energy storage systems. DSM controls the electrical consumption of loads at the distribution level to regulate the system frequency. Conventionally, researchers have designed the DSM load controller based on actual PV power output. However, such data may not be commonly available compared to solar irradiance. Thus, this paper presents a solar irradiance-based load controller for frequency regulation under high intermittency of PV. The preliminary results show that the proposed controller has a comparable performance versus a load controller that uses the actual PV power output data for frequency regulation. The proposed controller also can maintain the system frequency well within the statutory limit of 50 Hz ± 1 % and reduce the ROCOF by 0.033 Hz/s compared to the baseline when no load controller is used.