逆变器的双模式下垂控制

Control Method of Dual Mode Droop for Inverters

低压微电网中,逆变器普遍采用有功功率/电压(P-V)和有功功率/频率(P-f)下垂控制,这2种方法在不同负荷情况下对逆变器输出电压和频率表现出各自的控制优势。为减小逆变器输出电压和频率与额定值的偏差,提高系统电能质量,提出一种双模式下垂控制方式,逆变器可以根据具体负荷的变化情况在传统P-V和P-f下垂控制之间选择合适的方法。该控制模式在下垂控制环输出的电压和频率处直接切换,容易实现且模式切换过程平滑,可以减小逆变器输出电压和频率与额定值偏差,优化系统运行。仿真和实验验证了所提控制方法的有效性与可行性。

In low-voltage microgrid, active power v.svoltage（P-V） and active power v.s frequency（P-f） droop control methods are widely adopted among inverters. Both the two droop control methods show their respective advantages in the control of voltage or frequency in terms of different load conditions. In order to reduce the deviation between output voltage and rated value, this paper proposed a dual mode droop control method, in which the inverter can work with either P-V or P-f droop control according to the load conditions and update realtime. Changing voltage and frequency obtained by droop control to switch control method directly. This control mode is easy to achieve, and it can reduce the offset between output voltage and the rated value, further to optimize system performance. Simulation and experiment results validate the effectiveness and feasibility of the proposed method.