考虑泵类负荷特性的低压配电网分散无功补偿优化配置

Optimal Allocation on Distributed Reactive Power Compensation of Low Voltage Distribution Network Considering Pump Load Characteristics

针对以增氧泵、抽水泵等农业负荷为主的低压配电网台区常出现馈线末端电压过低而导致泵类负荷无法正常启动的问题,提出了考虑泵类负荷特性的低压配电网分散无功补偿优化配置模型。模型中目标函数综合考虑了补偿装置的投资成本和降低台区网损的经济效益,约束条件包括配电台区在泵类负荷正常运行和启动条件下的各种约束。采用sigmoid函数近似逼近目标函数中不连续的符号函数,并采用在离散取值附近曲率较大的非线性罚函数处理无功补偿容量的离散变量特性,进而采用原对偶内点法求解优化模型。通过对某个实际低压配电台区的计算分析,验证了该方法获得的补偿方案能够改善配电台区电压质量,保证泵类负荷的正常启动,并能有效降低台区网损。

In view of such problem as unable start of pump load due to excessive low voltage at the feeder which frequently occurs under the low voltage distribution network with such agriculture load as oxygen pumps and water pumps as foundation, in this paper, the optimal allocation model of distributed reactive power compensation of low voltage distribution network with consideration of pump load character is proposed. In the model, both investment cost and economic efficiency reducing network loss of the compensa- tion device is comprehensively considered in the objective function. And the constraint condition includes various constraints of the pump load at the distribution area under normal operation and starting condition. The discontinuous symbol function in the approximation objective function of sigmoid function is adopted and non-linear penalty function near the discrete value with curvature is adopted to proceed the discrete variable feature of the reactive power compensation capacity, thus primal-dual interior point algorithm is adopted further to solve the optimization model. It is verified by the calculation and analysis of certain actual low voltage distribution that the compensation scheme obtained by the method can be able to improve the voltage quality of distribution area, assure normal start of pump load and reduce effectively the network loss of the area.