V/v牵引供电所混合型电能质量控制系统负序优化补偿策略

摘要

为了解决V/v牵引供电系统负序和无功等问题,结合有源和无源的优势,研究了一种由铁路功率调节器和静止无功补偿器构成的低成本混合型电能质量控制系统.为了在不同负载工况下能够在线实时精确计算最优补偿容量,首先对混合补偿结构的原理进行分析,引入了二次侧两臂有功电流大小比KI、有功补偿系数λ、负序无功补偿角度ψ,进行了负序优化补偿的公式推导及理论分析.在一定的负序电压不平衡度下分析了λ与ψ之间的关系式,推导出有功与无功补偿之间的关系,并提出一种补偿方案进行容量优化.该方法不需要事先离线计算,可根据两臂负载情况在线实时精确计算最优补偿容量.实例计算和仿真分析表明了所提方法的正确性和经济性.%A low-cost hybrid power-quality management system is researched for the negative-sequence and reactive-power compensation of V/v traction power-supply system,which consists of a railway power conditioner with a static var compensator to take the advantages of both active and passive compensation technologies.In order to precisely calculate the optimal compensation capacity in real time and under different working conditions,the principle of hybrid compensation structure is analyzed.The active current ratio(KI) of two arms at secondary side,the active-power compensation coefficient(λ) and the negative-sequence reactive-power compensation angle(ψ) are introduced to carry out the theoretical analysis and derive the formula of optimal negative-sequence compensation.The relationship between λ and ψ is analyzed at a certain degree of negative-sequence voltage imbalance,the relationship between active-power compensation and reactive-power compensation is derived,and a compensation scheme is proposed to optimize its capacity,which,without the prior off-line calculation,can online calculate the optimal compensation capacity precisely in real time according to the loads of two arms.The results of case calculation and simulative analysis confirm the correctness and economy of the proposed scheme.