同相供电直挂变流器拓扑结构与容量匹配关系

摘要

To optimize the topology,improve the compensation capacity and decrease the space occupied by the equipment for co-phase power supply substations,universal transformation method about electrical parameters from three phase to single phase was adopted and three types of directconnected converters are investigated including full power converter,active power compensation converter and reactive power compensation converter.Based on active integrated compensation characteristics and power sub-module cha-racteristics,the topologies of three types of direct-connected converters were designed respectively.The matching relation between transformer connection mode and compensation capacity of direct-connected converters was also established.And,the capacity utilization ratio of power electronic device was determined in the end.The research results show that the associated compensation capacity is closely related to the connection modes of traction substation,as well as the connection port of the traction load and the type of load.For the converter with active power compensation,when the load power factor is greater than 0.961,it is better to choose the 90°connection traction transformer;when the load power factor is less than 0.961,it is better to choose the 120°connection traction transformer.For the converter with reactive power compensation,if the load is AC-DC-AC type,90°connection mode is preferable;if it is the inductive load,the connection mode of 120° is better than 90°.Under the conditions of the same AC-DC-AC traction load and the modulation index is 0.8,the converter with active power compensation has the highest utilization ratio of 11.34％ in device power capacity.%为优化同相供电变电所变流器的拓扑结构,改善补偿容量,并减少设备占地,运用牵引变电所三相-单相电气量通用变换方法,研究了功率直通型、有功补偿型和无功补偿型3类直挂变流器.结合有源综合补偿特性和功率子模块特点,设计了同相供电直挂变流器的拓扑结构,研究了牵引变电所接线形式与直挂变流器容量匹配关系,最后分析了直挂变流器的器件容量利用率.研究结果表明:有功补偿型和无功补偿型直挂变流器容量不仅与牵引变电所接线形式有关,还与牵引负荷的接入端口和负载类型有关;对有功补偿型,当负荷功率因数大于0.961时,宜选择90°接线牵引变压器,当负荷功率因数小于0.961时,宜选择120°接线牵引变压器,且牵引负荷接入超前相;对无功补偿型,当为交-直-交牵引负荷时,宜选择90°接线牵引变电所,当为感性牵引负荷时,宜选择120°接线牵引变电所.在相同的交-直-交牵引负荷及调制比为0.8条件下,有功补偿型直挂变流器的器件容量利用率最高,达到11.34％.