基于无源补偿网络的低压配电系统三相不平衡调节参数优化方法

Passive compensation network based optimal regulation parameter setting method of three-phase unbalanced voltage in low-voltage distribution system

受单相负荷运行随机性特点的影响,低压配电系统中普遍存在三相不平衡问题,目前已成为影响电能质量的主要因素之一。本文基于电感与电容构成的无源补偿网络,对低压配电系统三相不平衡调节参数的优化确定方法进行研究。分析了基于Steinmetz理论的三相四线制补偿网络结构;综合考虑低压配电系统负序与零序电流补偿,并以网络损耗与补偿电流最低为目标,得到了无源补偿网络优化调节参数的解析表达式。基于PSCAD建模仿真结果表明,该方法可有效降低三相不平衡度,改善负荷侧电压,提高功率因数,降低网络损耗。

Influenced by the operation randomness characteristics of load,there is generally three-phase unbalance problem in actual low-voltage distribution system.It has been one of main factors that affect the power quality greatly.The setting method for optimal regulation parameters to cope with the three-phase unbalance problems is presented in this article.It is based on the passive compensation network with capacitor and inductor.The compensation network based on Steinmetz theory is analyzed.Considering compensation of negative and zero sequence current in low-voltage distribution network,the optimal regulation parameter method is proposed to minimize the active power loss and compensation current.Simulation cases are carried out by PSCAD software.The simulation result shows that the presented method can effectively lower the three-phase voltage unbalance magnitude,improve the voltage,enhance the power factor and reduce the active power loss.