直流微电网参数自适应虚拟直流电机控制策略

Parameter adaptive virtual DC generator control strategy for DC microgrid

针对直流微电网中,负载功率突变会引起母线电压大幅波动,严重时导致系统失稳问题,以储能并联变换器为研究对象,提出一种基于微分补偿的虚拟直流电机参数自适应控制策略。该策略将储能变换器输出电压偏差反馈至微分补偿系数,使补偿系数跟随负载波动实时调节补偿系数大小,有效减小了功率波动对系统稳定性的影响,提高了系统动态性能,并且在并联系统中,可根据各变换器控制中电枢电阻的比值实现并联功率分配。建立了系统小信号模型,并利用伯德图和阻抗比判据分析关键控制参数对系统稳定性的影响。MATALB/Simulink仿真和StarSim HIL实验平台验证了本文虚拟直流发电机参数自适应控制策略的有效性。

Aiming at the problem that the sudden change of load power in the DC microgrid will cause the large fluctuation of bus voltage,even caused the system instability in serious cases,a virtual DC motor parameter adaptive control strategy based on differential compensation was proposed,taking the energy storage parallel converter as the study object.The strategy feedback the output voltage deviation of the energy storage converter to the differential compensation coefficient,so that the compensation coefficient can adjust the compensation coefficient size in real time as the load fluctuation,result in reducing effectively the impact of power fluctuation on the system stability,improving the dynamic performance of system,and realizing the parallel power distribution according to the ratio of the armature resistance in the control of each converter in the parallel system.The small-signal model of the system was established,and the influence of key control parameters on the system stability was analyzed by using Bode diagram and impedance ratio criterion.MATLAB/Simulink simulation and StarSim HIL experimental platform verify the effectiveness of the proposed parameter adaptive control strategy for the virtual DC generator.