大型光伏电站无功优化协调控制策略

为解决光伏电站因各种扰动引起的电压越限问题,光伏电站应具备无功调压能力.在分析单台光伏逆变器无功容量和光伏电站无功与电压关系的基础上,提出了一种大型光伏电站无功优化协调控制策略.该控制策略采用PI控制器实现电压的无差控制,并协调无功补偿装置和逆变器的无功容量为电网提供电压支撑,同时根据无功线路损耗对逆变器无功进行优化分配.结果表明:该控制策略能保证光伏电站并网点电压稳定,降低站内线路损耗,验证了所提控制策略的正确性.

Reactive power optimization coordinated control strategy for large-scale PV power station

In order to solve the voltage exceeding problem in the photovoltaic(PV)power station caused by various disturbances, the PV power station should possess the ability of reactive power voltage adjustment. On the basis of analyzing the reactive power capacity of single PV inverter as well as the reactive power and voltage relationship of PV power station, a reactive power optimization coordinated control strategy for large-scale PV power station was proposed. The non-difference voltage control was realized with the PI controller in the proposed control strategy. The reactive power capacity of both reactive power compensation device and inverters was coordinated to provide the voltage support for the power grid. Meanwhile, the optimal assignment for the reactive power of inverters was performed according to the reactive power line loss. The results show that the proposed control strategy can ensure the voltage stability of grid connection points in the PV power station and reduce the line loss in the station, which verifies the correctness of proposed control strategy.