低压微电网逆变器的自调节下垂系数控制策略

Control of Self-Adaptive Droop Coefficient for Inverter in Low Voltage Microgrid

由于传统下垂控制的微电网逆变器在离网状态下输出电压的幅值和频率不稳定,提出一种改进的自调节下垂系数控制,且加入电压和频率的误差反馈,减小了微电网在离网运行状态下负荷突变所引起的输出电压幅值和频率的偏差,且增强了其动态性能。同时传统的三相逆变器控制基于dq旋转坐标系,其并网功率冲击较大,而基于αβ静止坐标系下的控制能有效减小并网时的功率冲击,提高了系统的稳定性。仿真验证了该控制策略的正确性和有效性。

Due to the amplitude and frequency of output voltage of inverter was unstable with conventional droop control in microgrid, an improved adaptive droop control was proposed, which added error feedback of voltage and frequency. So it could reduce the deviation of output voltage amplitude and frequency when loads suddenly changed. At the same time the traditional three-phase inverter control based on the dq rotating coordinate system, the assauh of power to grid was very large, but control based on c~ stationary coordinate system could effectively reduce the assault of power to grid, and it improved the stability of the system. Through the MATLAB simulation, verified the feasibility of the system which used the method proposed.