Coordinated reactive power strategy using static synchronous compensator for photovoltaic inverters

摘要： Large photovoltaic (PV) penetrations into the electric grid resulted in new challenges such as reverse power flow and violation of voltage profile. The traditional methods for voltage regulation in a grid-connected PV system are hardly adaptable to these changes as they only contain the local information which is used without the knowledge of how the control action affects the overall system. To address this problem, this paper extends the reactive power control capability of solar PV inverters by combining them with static power electronic devices for regulating voltage during grid faults. For efficient identification of grid faults, a support vector machine-based fault classification mechanism is developed. The proposed method prioritizes the reactive power control using PV inverter by adapting a predefined hierarchical control structure. The complete methodology is realized by testing it with a two-stage single-phase grid-connected PV system. The experimental results verify the accuracy of the classification algorithm and depict the effectiveness of the proposed controller in both under and overvoltage situations.