含大规模分布式光伏接入电网的无功电压控制降损方法研究

大规模分布式光伏(distributed photovoltaic,DP)接入电网后,电网电压易出现大幅度波动,导致电网损失问题越来越突出。当前已有的电网降损方法没有考虑光伏发电自身的无功调节能力,应用效果不理想。为此,设计一种含大规模DP接入电网的无功电压控制降损方法。通过建立目标函数,设定约束条件,采用敏感性分析方法分析电压稳定性,将敏感度较高的值作为无功补偿位置,并对当前负荷进行预测,确定最佳的补偿容量,实现电网降损。试验结果表明,所提方法降损后较降损前基准电压更趋于1 pu,更为稳定,所提方法能够针对光伏控制接入分布特性,有效控制无功功率变化情况,相对于其他方法,无功功率波动较小,表现出较好的降损效果。

Reactive Power and Voltage Control Loss Reduction Method With Large-scale DP Connected to Power Grid

After the large-scale distributed photovoltaic (DP) is connected to the power grid, the voltage of the power grid tends to fluctuate greatly, resulting in more and more serious power grid losses. At present, the existing power grid loss reduction methods do not consider the reactive power regulation ability of photovoltaic power generation, and the application effect is not ideal. Therefore, a reactive power voltage control loss reduction method with large-scale DP connected to the power grid is designed. Through establishing objective function, setting constraint conditions, analyzing voltage stability by sensitivity analysis method, taking the value with higher sensitivity as the reactive power compensation position, and forecasting the current load to determine the best compensation capacity, so as to realize power grid loss reduction. The experimental results show that the reference voltage of the proposed method tends to 1pu and is more stable after loss reduction than before. The proposed method can effectively control the change of reactive power according to the distribution characteristics of PV control access. Compared with other methods, the fluctuation of reactive power is small, showing a good loss reduction effect.