城市轨道交通超级电容储能装置控制策略

Control Strategy for Super Capacitor Energy Storage Device of Urban Rail Transit

以城市轨道交通地面式超级电容储能装置为背景,针对空载电压波动下的储能装置阈值选择问题进行探讨,首先分析城轨供电系统中空载电压波动对再生能量回收的影响:1)更改储能装置放电电压指令,可以改变储能装置和整流机组能量输出的功率比例;2)传统恒定阈值放电策略将放电指令与放电阈值固定,因此储能装置放电时不能做到对放电功率的控制;3)采用固定阈值放电策略时,空载电压值的变化会影响储能装置放电输出能量的大小。然后提出充放电阈值动态调整控制策略,实验结果表明,对于不同的空载电压,改进后的控制策略可以根据空载电压放电指令进行动态调整,使储能装置与整流机组的能量输出比例恒定,从而维持放电时放出的能量不随空载电压的波动而变化。

Taking the ground type super capacitor energy storage device of urban rail transit as the research background, the threshold selection of energy storage device under no-load voltage fluctuation is discussed. Firstly, the influence of no-load voltage fluctuation on regenerative energy recovery in urban rail power supply system is analyzed： 1 ） changing the discharge voltage command of the energy storage device can change the power ratio of the energy output of the energy storage device and the recti- fier unit; 2 ） the traditional constant threshold discharge strategy keeps the discharge command and the discharge threshold fixed, so that the discharge power cannot be controlled when the energy storage device discharges; 3 ） when the fixed threshold discharge strategy is adopted, the change of the no-load voltage will affect the output energy of the energy storage device. Then the dynamic adjustment control strategy of charging and discharging threshold is put forward. The experimental results show that for different no-load voltage, the improved control strategy can dynamically adjust according to the no-load voltage discharge voltage command, retain the energy output ratio of the energy storage device and rectifier unit discharge so as to maintain the constant release of energy with no-load voltage fluctuations and changes.