光伏并网发电及无功调节策略的研究

设计了一种将无功调节与并网发电相结合的光伏并网功率控制系统,使光伏并网逆变器在向电网提供有功功率的同时输出电网所需的无功功率。详细分析了系统数学模型、控制结构、无功功率控制方法,并计算了其无功功率极限。结合光伏电站远程调度通讯协议,利用500 kW光伏并网逆变器样机实现了并网发电和无功功率调节的统一控制。仿真结果表明,在电网发生故障时,光伏电站可发送无功以支撑并网点电压,提高了电网电压的稳态性。

Research on the Strategy of Photovoltaic Grid-connected Generation and Reactive Power Regulation

It designed a photovoltaic （PV） grid-connected power conditioner system integrating grid-connected generation and reactive power regulation, in which the PV grid-connected inverter can provide active power for grid and output reactive power which the grid demand. System mathematic model, control structure and reactive power control method were discussed and the limit of reactive power output was calculated. Based on the communication protocol of PV power station, the uniformed control of reactive power regulation and PV grid- connected generation has been implemented in the prototype of 500 kW photovoltaic grid-connected inverter. Simulation results show that the PV power station can output reactive power to support voltage of PCC（point of common coupling） when faults happen and can improve the stability of local grid voltage.