动态电压恢复器的能量稳定控制

Energy Steady Control for Dynamic Voltage Restorer

针对动态电压恢复器(DynamicVoltageRestorer,DVR)提出了一种能量稳定控制策略,该策略综合了已有的负荷电压固定补偿,同相电压补偿和最小能量补偿三种负荷电压控制策略的优点而避免了各自的缺点,在实现DVR补偿目标的同时,优化了DVR与系统的能量交换过程,减少了所需要的设备容量并增加了有效补偿时间,提高了经济性和可靠性。采用该控制策略的DVR不需要整流充电单元也能够在发生电压跌落或电压上升后的较短时间内恢复其直流储能单元的能量,同时避免了系统电压上升时,DVR吸收能量导致直流侧过电压带来的安全威胁。最后用仿真试验验证了该控制策略的实用性和有效性。

An energy steady control strategy for dynamic voltage restorer （DVR） is proposed, in which the advantages of existing three load voltage control strategies, i.e., the pre-fault compensation, the inphase voltage compensation and the energy optimal compensation, are integrated and the demerits of them are avoided. The energy exchange process between a DVR and the power system is optimized while the compensation target is implemented, therefore the equipment＇s capacity required by DVR can be reduced and the effective compensating time is increased, thus the economy and reliability are improved. Using the proposed control strategy, without rectifying and charging unit the energy in DC energy storage unit of DVR can be restored within a shorter time period after the voltage sag or swell occurred, meanwhile the danger to security from the overvoltage at DC side caused by the absorbed energy of DVR during the rising of system voltage can be avoided. The practicability and effectiveness are verified by simulation results.