Photovoltaic Active Support Control Technology Based on Active Power Reserves

With the increasing proportion of photovoltaics (PV) in power system, the power system urgently needs PV to provide inertia to the system and have active voltage support capability during faults, however, PV faces difficulties in achieving these functions without energy storage. 1. The maximum power point needs to be estimated by measuring the irradiance and temperature through the sensor or other methods. 2. Power imbalance between the source side and the load side leads to DC – link voltage imbalance. To address these issues, this paper proposes a two-stage photovoltaic virtual synchronous generator(PV-VSG) control strategy based on active power reservation. This strategy can achieve power reservation without estimating the maximum power point(MPP) and automatically complete power matching. It allows PV to operate stably in the left half-plane of the characteristic curve, provide inertia to the system, participate in primary frequency regulation, and have active voltage support capability. The grid-connected and islanding models are simulated and validated on the Matlab/Simulink platform by applying irradiance, load, and fault disturbances, demonstrating the effectiveness of the proposed strategy. A comparison with traditional grid-following control of PV systems is conducted to demonstrate the superiority of this strategy.