末端配电网负荷三相不平衡状态监测及优化控制策略研究

Research on Monitoring and Optimizing Control Strategy of Three-Phase Unbalanced State of End Distribution Network Load

配电网负荷在三相不平衡工况下运行时,中性线流过电流会增加线路损耗甚至损坏用电设备,危及电网运行安全。针对上述问题,提出了一种基于智能换相开关线上择优调整负荷相序来控制三相不平衡度的方法。首先,介绍了配电网智能换相开关装置双开关结构拓扑及换相原理。其次,以末端配电网三相电流不平衡度最低和智能换相开关装置调整负荷相序动作次数最少为目标,建立了多目标优化换相数学模型,并结合NSGA-Ⅱ算法和末端配电网换相策略进一步实现对智能换相开关的控制。最后,通过算例仿真和在某小区投运设备前后进行试验分析,验证了该换相开关及控制方法在末端配电网三相不平衡度改善中的有效性。

When the distribution network load is operated under three-phase unbalanced conditions,the neutral(zero)line flowing through the current will increase the line loss and even damage the electrical equipment,which endangers the operation safety of the grid.According to the above problems,a method based on the intelligent phase-switching switch line to adjust the load phase se-quence to control the three-phase unbalance is proposed.Firstly,it introduces the dual switch structure topology and commutation principle of intelligent commutation switch in distribution network.Secondly,a multi-objective optimized commutation mathematical model with the lowest three-phase current imbalance of the end distribution network and the minimum phase sequence of the intelligent commutation switch device is established,and combined with NSGA-II algorithm and terminal distribution,the network commutation strategy further realizes the control of the intelligent commutation switch.Finally,through the simulation of the example and the exper-imental analysis before and after the operation of the equipment in a certain district,the effectiveness of the commutation switch and the control method in the improvement of the three-phase unbalance of the end distribution network is verified.