一种用于并网电流控制器的有源高频阻尼方法

An Active High Frequency Damping Scheme for the Current Control of Grid-connected Interface

在数字控制器的应用中,并网逆变器的电感电流控制增益总是受到电感值、控制频率以及数字控制器实现时的控制延时限制。增加控制增益和提高系统稳定裕度之间存在固有矛盾。因此,针对大增益引起的谐波和稳定性问题,进行根本原因分析,提出了一种虚拟高频阻尼方法(VHD)来解决数字控制器对于电流控制增益的限制,并且也提出了一种改进的电流预测(CP)单元。Matlab仿真和实验结果验证了虚拟高频阻尼方法的有效性,并且电流环增益得到了放大。

The inductor current control gain of grid connected inverter is always limited by inductance value and control frequency as well as control delay when the implementation of digital control.There is an inherent contradiction between increasing the control gain and improving the system stability margin of the system.Therefore,for the problems of harmonic and stability by the increase of gain,the basic reason was analysised.A virtual high-frequency damping(VHD)method was proposed to overcome the digital control limitations for the current control gain,and an improved current predictive(CP)unit was provided as well.The effectiveness of the proposed VHD has been verified by Matlab simulations and experimental results,and the current loop gain has been greatly expanded.