基于模糊自适应PI控制的柔性直流输电系统实验研究

柔性直流输电在联接无源网络时,对其控制的关键是对无源网交流电压和频率的控制.针对联接无源网的控制方法进行研究和实现,结合实际计算机控制器,提出了柔性直流输电交流电压和频率离散化控制原理.引入了作用模糊子集推理方法,与DSP运算特点结合,应用于PI参数自调整.提出了基于作用模糊子集推理的DSP模糊控制实现方法:根据系统状态的偏差、偏差变化和隶属函数求作用模糊子集和相应的隶属度;根据最小值原则计算前件真值.并按各自模糊控制规则将真值传给后件;确定输出的模糊量,并计算相应的隶属度:利用加权平均法反模糊化并在线自修正PI参数.开发了VSC-HVDC的DSP交流电压控制器.进行了模糊自适应PI控制的实验研究.结果表明,对VSC-HVDC交流电压控制采用作用模糊子集的自适应PI控制是有效的.

Experimental study of VSC-HVDC under fuzzy adaptive PI control

When VSC-HVDC system connects with passive network,the AC voltage and frequency control of the passive network is essential.Combined with real computer controller,its discrete control strategy is presented.The functioning -fuzzy -subset inference method is introduced into the adaptive regulation of PI parameter,and its implementation with DSP(Digital Signal Processor) is put forward:the functioning -fuzzy -subsets and corresponding membership degrees are solved according to the membership functions and the error and its change rate of system status;the antecedent truth values are calculated based on the minimum value principle and passed to the consequent one;the fuzzy outputs and corresponding membership degrees are determined;defuzzification is performed using the weighted average method and the PI parameters are online regulated.The DSP -based AC voltage controller for VSC -HVDC is developed and the experimental study of fuzzy adaptive PI control is carried out.The experimental results show its effectiveness.