提高直流微电网稳定性的有源阻尼方法

摘要

In order to solve the unstable problem in DC microgrid caused by large amount of constant power load, this paper presents a new active damping control method based on the DC current feed forward of grid connected inverter. It also studies the mathematical model of grid connected DC-AC interfacing converter in the DC microgrid as well as the control strategy of active damping method for the DC-AC converter. Accordingly, the small signal mathematical model of the DC microgrid is established. Based on the dominant pole distribution and impedance matching principle, the adverse impacts of constant power load on the stability in DC microgrid and the improvement for the system stability by the active damping method are analyzed. The parameter design principles of the active damping are provided. The simulation and experimental results show that the proposed active damping control method can improve the stability of the DC microgrid with high penetration of constant power load.%为解决直流微电网中恒功率负载大量接入引发的系统不稳定问题,提出一种基于并网接口变流器直流电流前馈的有源阻尼控制方法.研究直流微电网的并网接口DC-AC变流器数学模型和适用于DC-AC变流器的有源阻尼方法的控制策略,建立直流微电网的小信号数学模型.基于系统主导极点分布和阻抗匹配原则,分析恒功率负载对系统稳定性的不利影响及有源阻尼方法对系统稳定性的改善作用,并给出有源阻尼参数的设计原则.仿真和实验结果表明,所提有源阻尼方法可以提高在恒功率负载高渗透率下的直流微电网系统稳定性.