用于电铁平衡化补偿的SVG研究与应用

Research and Application of SVG for Balanced Compensation of Electric Railway

在电气化铁路牵引供电系统中,单相27.5 kV机车为主要不平衡负荷,针对V/V牵引变压器铁路供电系统提出平衡化补偿方案。在补偿形式上,链式角接静止无功发生器(SVG)直接并联于27.5 kV接触网和铁轨;在控制策略上,基于瞬时无功功率理论提取负载电流的正序和负序分量,并从零序环流注入的角度考虑直流侧电压的平衡问题,进而生成包含正序、负序和零序电流在内的总的相电流指令,由此提出正序零序电流比例积分(PI)控制与负序电流积分控制相结合的控制方法。根据该控制方法,搭建了Matlab仿真模型,对主要控制环节的作用进行了验证。该方案在国内某铁路牵引变电站取得了成功应用,简要说明了链式角接SVG在该项目的安装及补偿情况,分析了运行效果,验证了该补偿方案的有效性与实用性。

In the traction power supply system of electric railway,single-phase 27.5 kV locomotive is the main unbalanced load.A balanced compensation proposal is presented for railway power supply system of V/V traction transformer.In the form of compensation,cascaded static var generator(SVG)in delta connection is directly connected to the catenary and rail in parallel.For control method,the positive and negative sequence components of load current are extracted based on instantaneous reactive power theory,and the DC side voltage balance is considered from the perspective of zero sequence current injection.Then,the total phase current reference including positive,negative and zero sequence current is generated.Thus,a control method combining positive and zero sequence current proportion integration(PI)control and negative integral control is proposed.Matlab simulation model is established to verify the role of mayor control parts.This proposal has been successfully applied in a domestic traction substation,a brief description and result analysis are made for this application to further verify the effectiveness and practicability of this proposal.