摘要: |
基于原牵引变电所的结构和接线,增设断路器和变流器。通过闭合和开断断路器,使牵引网电压相位一致,实现异相供电向同相供电的转换;变流器作为平衡变换装置,当端口接线角相差 ± 90° 时,采用背靠背单相变流器,相差 ±120° 时,根据接线形式分别采用三桥三端子或三桥四端子变流器;根据所给出的补偿电流公式,不同的平衡变换装置均可输出期望的补偿电流,解决同相供电方式带来的负序电流叠加问题。仿真结果表明,平衡装置投入后,电力系统三相电流为对称的纯正弦基波波形与高频调制波形的叠加,是与电压同相位的正弦波。 |
关键词: 铁路 牵引 断路器 变流器 补偿 |
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Transfer from out-phase power supply to in-phase power supply |
ZHANG Gangyi1, LI Qunzhan2
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1.Electrical Engineering Institute,Xi’an Railway Vocational and Technical Institute,Xi’an 710014,China;2.School of Electrical Engineering,Southwest Jiaotong University,Chengdu 610031,China
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Abstract: |
The out-phase power supply is transferred to in-phase power supply by applying additional breakers and converters to original structure and lines of traction substation. The phases of traction voltage become consistent by switching on/off the breakers. The converter is used as balancing device. Single-phase back-to-back converter is applied when the phase difference between two ports is ± 90°,while three-bridge three-terminal or three-bridge four-terminal converter is applied according to the connection mode when the phase difference is ±120°. The expected compensative current is generated by the balancing device according to the given formula to avoid the superposition of negative currents caused by in-phase power supply. Simulative results show that,the three-phase current of power system is the superposition of the sine fundamental wave and the high-frequency modulation wave,which is in-phase with the voltage. |
Key words: railroads traction circuit breakers electric converters compensation |