组合式同相供电系统的网侧功率因数和不平衡度分析

Analysis on Grid Side Power Factor and Unbalanced Degree of Combined Co-phase Power Supply System

组合式同相供电系统容量配置对补偿效果和工程造价至关重要,在牵引负荷无功和负序全补偿、欠补偿的情况下,分析了单相以及单三相组合式同相供电系统中,补偿后电网侧的功率因数和不平衡度与补偿装置和牵引变压器的容量比、无功补偿度、以及牵引负荷功率因数之间的关系。以补偿后网侧功率因数和不平衡度是否满足国标作为满意补偿的约束条件,分别以补偿装置容量、补偿装置以及牵引变压器容量和最小为目标函数,建立2种优化模型。最后,通过Matlab/Simulink仿真结果验证了建立的目标函数、设置约束条件以及优化结果的正确性。计算和仿真结果分析表明,相同牵引负荷条件下,单三相组合式补偿后的网侧功率因数高于单相组合式;单三相组合式同相供电系统的网侧电流不平衡度高于单相组合式;牵引变压器和补偿装置的容量比为1时,网侧负序不平衡度为0。

Capacity configuration of combined co-phase power supply system is crucial to the compensation effect and project cost.In the case of full compensation and under compensation of traction load reactive power and negative sequence,we analyzed the relationship between the power factor as well as unbalance of the compensated grid and the parameters such as the capacity ratio of the compensation device and the traction transformer,the reactive power compensation,and the traction load power factor by combining co-phase supply system with a single-phase modular and co-phase power supply system based on the single-phase and three-phase transformer.Moreover,considering it as a constraint for satisfactory compensation whether the power factor at the grid side and the unbalanced degree after compensation meet the national standard,and treating it as an objective function which is the capacity of the compensation device,minimum capacity of the compensation device and the traction transformer,we established two optimization models.Finally,the established objective function,set constraints,and the correctness of the optimization result are verified by Matlab/Simulink simulation.Under the same traction load conditions,the calculation and simulation results are as follows：the network side power factor of co-phase power supply system based on the single-phase and three-phase transformer is higher than that of combined co-phase supply system with a single-phase modular.The grid side unbalanced current of co-phase power supply system based on the single-phase and three-phase transformer is higher than that combined co-phase supply system with a single-phase modular.The grid side negative sequence unbalance degree is 0 when the capacity ratio of the traction transformer and the compensation device is 1.