牵引变电所群贯通供电系统负序补偿模型及控制策略

针对牵引变电所群贯通供电系统存在的三相电压不平衡问题,提出一种基于三相变压器与静止无功发生器(SVG)的负序集中补偿方案及控制策略.首先,根据牵引变压器的功率变换关系及不同的负荷情况,推导了2种模式下补偿装置对牵引负荷的补偿功率通用表达式.根据中国的电能质量标准,提出了以负序满意补偿为目标的双限值补偿方案,方案包括了模式选择方法、SVG容量配置方法及SVG运行方法.根据补偿方案,设计了带有模式判别的SVG双闭环补偿控制策略.然后,采用牵引变电所实测数据对补偿方案进行验证,证明了方案具有良好的补偿效果,与全补偿方案相比,所提方案需要的装置容量更小.最后,通过仿真证明了控制策略对负序补偿的有效性和较快的响应速度.

Negative Sequence Compensation Model and Control Strategy for Interconnected Power Supply System of Traction Substation Group

Aiming at the three-phase voltage unbalance problem of the interconnected power supply system of traction substation groups, a negative sequence centralized compensation scheme and control strategy based on three-phase transformer and static var generator (SVG) are proposed. First, according to the power transformation relation of the traction transformer and different load conditions, general power compensation expressions of compensation devices for the traction load in two modes are deduced. According to the power quality standards in China, a double-limit compensation scheme is proposed aiming at satisfactory negative sequence compensation, which includes mode selection method, SVG capacity configuration method and SVG operation method. According to the compensation scheme, the SVG double closed-loop compensation control strategy with mode discrimination is designed. Then, the compensation scheme is validated with measured data of traction substations, which proves that the scheme has good compensation effect. Compared with the complete compensation scheme, the proposed scheme requires smaller device capacity. Finally, it is proved through simulations that the control strategy is effective in negative sequence compensation and has fast response speed.