集中式逆变器直流侧并联协调控制策略

Centralized Inverter Parallel Coordinated Control Strategy

针对集中式光伏电站逆变器低功率运行下输出波形质量差且故障率高的问题,在光伏发电单元汇流箱与逆变器之间加入控制器,提出一种改善系统运行性能的控制策略。分析了集中式光伏电站直流侧并联结构,以光伏系统输出功率最大和输出电流谐波畸变率最小为优化目标,建立目标函数。控制器控制逆变器协调运行使目标函数最小,改善系统运行性能。分析了光伏单元传统连接方式下故障期间的损失以及本策略在此基础上可提高的效益。最后通过算例验证本策略的可行性。

To solve the problem of poor output waveform quality and high failure rate under low-power operation of centralized photovoltaic power station inverter,a control strategy was proposed to improve system performance by adding a controller between the photovoltaic power generation unit bus box and the inverter.The parallel structure of the DC side of the centralized photovoltaic power station was analyzed,and the objective function was established with the maximum output power of the photovoltaic system and the minimum harmonic distortion rate of the output current as the optimization objectives.The controller controls the inverter coordinated operation to minimize the objective function and improve the system performance.The loss during the failure of photovoltaic cell under the traditional connection mode and the benefit that can be improved based on this strategy are analyzed.Finally,examples were given to verify the feasibility of this strategy.