光伏电站的无功补偿技术

Reactive Power Compensation Technology for Photovoltaic Power Station

光伏发电是目前最环保的发电方式之一,因此并网型光伏电站的应用也逐渐普及开来。首先对光伏电站的系统结构以及无功需求组成进行了介绍;然后通过对光伏电站1日无功变化特性的分析,得到光伏电站在夜间时的无功功率主要为汇集电缆的容性充电功率,而在白天时的无功功率受到天气和云层的影响,具有很强的随机性和波动性;最后根据光伏电站的无功变化特性,并基于光伏逆变器是否参与无功补偿2种情况下,提出2种无功补偿方案。所提无功补偿方案都是将FC/TSC与STATCOM进行组合形成动态无功补偿,不仅可以满足光伏电站的无功功率需求,还具有一定的经济性。

At present, photovoltaic power generation is one of the power generations with most environmental protection, therefore, the application of grid-connection photovoltaic power station is gradually spread. In this paper, firstly, the system structure and reactive power requirements of photovoltaic power station are introduced, and then the reactive power which is capacitive charging power of cables of the photovoltaic substation at night is obtained through the analysis of 1-day reactive power variation feature of photovoltaic power station. The reactive power in day time has very strong randomness and volatility due to the influence of weather and clouds. Finally, two types of reactive power compensation scheme are proposed in accordance with the reactive power variation feature of photovoltaic power station and also based on whether or not the involvement of reactive power compensation by the photovoltaic inverter. The proposed reactive power compensation scheme is to combine FC/TSC with STATCOM to form dynamic reactive power compensation, which not only meets the needs of reactive power of photovoltaic power station, but also has some economic efficiency.