适用于网格状的交直流微网协调控制策略

A Coordinated Control Strategy for Networked AC/DC Microgrid

针对网格状交直流微网的功率分配不均和稳定性差等问题,提出了一种新型自适应协调控制策略,以提升交直流微网系统的稳定性和功率分配精度。首先,针对连接交流微网和直流微网的变流器,提出了一种基于同步器和虚拟直流机(VDCM)的控制策略,该策略包括功率分配控制器、自适应虚拟调速器和自适应虚拟惯量调节器;接着,为了提高系统的稳定性能,还提出了自适应虚拟惯量和虚拟调速器增益的参数设计方法,其中,自适应虚拟惯量和虚拟调速器增益的参数设计完全取决于系统频率、直流电压、虚拟转子转速、频率变化率和直流电压变化率。在此基础上,对上述控制系统进行了小信号稳定性分析,以指导控制器参数的设计和选择。最后,仿真和实验结果验证了所提方法的有效性。

Aiming at the problems of uneven power distribution and poor stability of grid AC/DC microgrid,a new adaptive coordinated control strategy was proposed to improve the stability and power distribution accuracy of AC/DC microgrid(MGs)system.First,for converters connecting AC microgrids and DC microgrids,a control strategy based on the synchronverter and virtual DC machine(VDCM)for the converters connecting the AC and DC MGs was proposed,which is consisted of a power distribution controller,an adaptive virtual governor and an adaptive virtual inertia regulator. Following,in order to enhance the system stability performance,the parameter design approach of the adaptive virtual inertia and virtual governor-gain was proposed accordingly,in which,the adaptive virtual inertia and virtual governor-gain are comprehensively determined by the frequency,DC voltage,virtual rotor speed and rate of change of the frequency and DC voltage. After that,the small-signal stability of the proposed control system was analyzed to guide the design and selection of controller parameters. Finally,simulation and experimental results verify the effectiveness of the proposed method.