Distributed virtual inertia based control of multiple photovoltaic systems in autonomous microgrid

The large inertia of a traditional power system slows down system U+02BC s frequency response but also allows decent time for controlling the system. Since an autonomous renewable microgrid usually has much smaller inertia, the control system must be very fast and accurate to fight against the small inertia and uncertainties. To reduce the demanding requirements on control, this paper proposes to increase the inertia of photovoltaic U+0028 PV U+0029 system through inertia emulation. The inertia emulation is realized by controlling the charging U+002F discharging of the direct current U+0028 DC U+0029-link capacitor over a certain range and adjusting the PV generation when it is feasible and U+002F or necessary. By well designing the inertia, the DC-link capacitor parameters and the control range, the negative impact of inertia emulation on energy efficiency can be reduced. The proposed algorithm can be integrated with distributed generation setting algorithms to improve dynamic performance and lower implementation requirements. Simulation studies demonstrate the effectiveness of the proposed solution.