井下局部通风机储能型变流器控制策略研究

Research on control strategy of energy storage converter of mine local ventilator

针对传统集中式变流器的结构已无法满足井下通风机应急供电需要的问题,设计了一种集充放电为一体的双级式井下局部通风机储能型变流器,该储能型变流器既能在系统停电时作为应急电源使用,又能实现电网正常运行时的无功补偿功能。提出了双级式储能型变流器的控制策略:当局部通风机的双回供电线路正常工作时,储能型变流器处于在线运行模式,PWM逆变器采用P/Q控制策略,此时主要对蓄电池进行充电并对电网进行无功补偿;当局部通风机的双回供电线路出现故障时,储能型变流器处于应急供电模式,PWM逆变器采用V/f控制策略。提出了一种基于状态反馈共电流内环的平滑切换控制策略,将V/f控制器状态与P/Q控制器的输出反馈至输入,用以解决储能型变流器在应急供电和在线运行时2种运行模式切换过程中产生的电流冲击问题,实现储能型变流器的平滑切换。仿真结果表明:在2种运行模式下,该控制策略可使变流器实现稳定运行,并能够实现平滑切换,具有较好的稳态与动态特性。

For structure of traditional centralized converters cannot meet emergency power supply requirements of mine local ventilators,a two-stage energy storage converter of mine local ventilator integrating charge and discharge was designed.The energy storage converter not only can use as an emergency power source when the power grid is out of power,but also can achieve reactive power compensation function during normal operation of power grid.A control strategy for two-stage energy storage converter was proposed.When dual-circuit power supply line of local ventilator works normally,the energy storage converter is in online operation mode,and the PWM inverter adopts P/Q control strategy,which mainly charges battery and compensates reactive power to the grid.When dual-circuit power supply line of local ventilator fails,the energy storage converter is in emergency supply mode,and the PWM inverter adopts V/f control strategy.A smooth switching control strategy based on state feedback and common current inner loop was put forward.The state of the V/f controller and the output of the P/Q controller are feedback to the input to solve the problem of current impact occurred during the switching of the two operating modes of the emergency power supply and online operation of the energy storage converter,so as to achieve smooth switching of the energy storage converter.The simulation results show that the control strategy enables the converter to operate stably and switch smoothly under two operating modes,which has good steady and dynamic state characteristics.