基于双电压环补偿的直流微网下垂控制

针对直流微网传统下垂控制中分布式电源(distributed generation,DG)输出功率分配精度和电压维持额定值间的矛盾,提出了一种基于双电压环补偿的直流微网下垂控制方法。该方法基于集中式二级控制和对等下垂控制策略,在二级控制中引入双电压环控制,其中,第一电压环保证负载功率的高精度分配,第二电压环抬高系统电压,使其更接近额定值。该策略使直流微网系统具有良好的稳态和动态分流特性,能够实现不同容量等级变换器间输出功率的精准分配,且同样适用于本地负荷不匹配的情况。仿真结果表明该控制方法可以保证良好的功率分配精度,维持电压在较高水平,并兼顾系统的动态响应。

DC-Microgrid Droop Control Based on Double Voltage Compensation

In view of the contradiction between the distribution accuracy of distributed generation (DG) output powers and high voltage level in the traditional droop control of DC microgrid, a DC-microgrid droop control based on double voltage compensation is proposed in this paper. The method is based on the centralized secondary control and the peer-to-peer droop control strategy, and double voltage loop control is designed into the secondary control. The first voltage loop ensures high accuracy distribution of load power, and the second voltage loop raises the system voltage closer to the rated value. The strategy makes DC microgrid system have good steady state and dynamic characteristics, can realize the accurate distribution of output power among converters with different capacity, and can deal with local load mismatch. The simulation results show that the proposed control method can ensure good power distribution accuracy, maintain the voltage at a high level, and take into account the dynamic response of the system.