具备电压补偿功能的不停电过分相系统及控制方法

Study on the Control Method and the Uninterrupted Phase-Separation Passing System with Voltage Compensation Function

不停电过分相系统可保证机车连续供电,避免机车运行速度降低和遭受冲击电压电流。为进一步提高不停电过分相系统的可靠性和改善牵引供电网末端电压波动,该文提出一种基于三相模块化多电平变换器(MMC)的分相区不停电过分相系统(UPT)及其控制策略。首先,基于三相MMC的分相区UPT拓扑结构及其工作原理,分析了机车通过分相区域导致的牵引网末端电压波动原理和UPT的无功电压补偿能力;然后,在机车经过分相区的全过程中,分析UPT的电流传输特性,以保证两侧供电臂负荷有功分量线性变化;接着,提出了UPT的有功、无功以及整体的控制策略;最后,进行仿真分析和小容量实验。理论分析和实验结果表明:UPT能保证机车在不停电状态下平稳通过分相区,两侧供电臂负荷实现线性平稳变化,同时有效地解决了电压波动的问题。

The uninterrupted phase-separation passing system can ensure the continuous power supply of locomotive without speed reduction and voltage and current impact.In order to further improve the reliability of the uninterrupted phase-separation passing system and the voltage fluctuation at the end of the traction power supply network,a uninterrupted power transfer system(UPT)based on three-phase MMC and its control strategy are proposed.Firstly,the UPT topology and working principle of the phase separation zone based on three-phase MMC are studied;secondly,the voltage fluctuation principle at the end of traction network caused by locomotive passing through the neutral section and the reactive voltage compensation ability of UPT are analyzed.Then,during the whole process of locomotive passing through the neutral section,the current transmission characteristics of UPT are proposed to ensure the linear change of active load on both sides.Next,the active and reactive power of UPT and the overall control strategy are proposed.Finally,simulation analysis and small capacity experiment are carried out.The theoretical analysis and test results show that the UPT can ensure that the locomotive can smoothly pass through the neutral section without power failure,and the load of traction power supply arms on both sides can realize linear and stable change,and effectively solve the problem of voltage fluctuation.