MMC控制策略比较分析研究

Research on comparative analysis of MMC control strategies

为了研究MMC的控制算法,将模型预测控制应用于MMC系统中,为了获得更好的控制效果,在模型预测控制中引入了死区补偿;并与传统的PI控制器进行深入比较分析。最后通过样机实验表明:两种控制算法在控制MMC输出电压、电流,环流和电容电压平衡控制等方面均具有很好的控制效果;尽管模型预测控制输出电流波形质量不如传统PI控制器优良,但是在电容电压平衡方面表现出很大的优势;并且由于模型预测控制能知晓下一时刻的开关状态,并能预测最优的开关组合状态,所以比传统PI控制表现出更快的动态响应特性。

Aiming at study the MMC control strategies, model predictive control was applied to MMC sys- tem. In order to achieve the better control results, dead-time compensation was introduced in model pre- dictive control, and it made an in-depth analysis compared with the traditional PI controller. Finally, the prototype test results indicate that both control strategies can obtain good results on controlling MMC out- put voltages, currents, sub-model capacitor voltages and suppressing circulating currents. Although the output currents by model preditive control are not as good as that by traditional PI controller, the model preditive control has a great advantage on capacitor-voltages balancing. Besides, the dynamic perform- ance of model preditive control is even superior to the considered PI control, due to the prediction of the future converter behavior.