DVR和逆变式微电源配合补偿微电网中电压暂降问题的研究

Compensating Voltage Sags in Microgrid Using Dynamic Voltage Restorer and Inverter Microsource

对电压暂降原理和动态电压恢复器的补偿范围进行理论分析,提出利用PWM逆变式微电源配合DVR补偿微电网中电压暂降的策略。DVR储能容量的大小直接决定装置的成本,为在储能容量一定的前提下提高DVR的补偿能力,在补偿过程中让逆变式微电源相应多注入一些功率,分担DVR的有功注入,从而增大DVR的电压补偿范围。对发生电压暂降后DVR单独不能满足全相补偿的情况,采用PSCAD/EMTDC对逆变式微电源输入功率变化前后DVR的补偿能力进行仿真验证,结果表明通过增加PWM逆变式微电源的输出,能有效增大DVR的补偿能力,减轻暂降给负荷带来的影响。

Based on the theoretical analysis of voltage sag principles and the compensation scope of dynamic voltage restorer, a strategy for compensating voltage sags in microgrid is proposed by using dynamic voltage restorer （DVR） and inverter microsource. The capacity of energy storage unit in DVR determines the cost of device and the compensation capacity of DVR to a large extent. In order to improve the compersation capacity under constant capacity of energy storage, more power should be injected during the process of voltage sags by PWM inverter microsource to share the burden of DVR, and enhance the compensation capability of DVR. The simulation on PSCAD/EMTDC is done to testify the variations of DVR＇s compensation capability through altering the injection of inverter microsources under the cir- cumstance that the pre-sag compensation can not be satisfied by DVR. Results show that with the cooperation of inverter micro source, DVR＇s capability of compensation is strengthened, and the impact of voltage sag on the load is minimized.