双模糊控制法在光伏并网发电系统MPPT中的应用

提出一种在光伏并网发电系统中进行最大功率点跟踪(MPPT)的双模糊控制法,将非对称模糊MPPT与模糊PID相结合,在设定参考电压环节使用模糊控制代替诸如扰动观察法等传统方法,在消除实际电压与参考电压偏差这一环节用模糊PID替换普通的PID控制。此外,还提出了4个反映MPPT性能的指标:环境缓慢变化时的MPPT时间、光伏阵列发出的能量大小、稳态时的功率波动大小和环境剧烈变化时光伏阵列发出的能量大小。设计了4个算例,在MATLAB/Simulink环境下对5种控制方法分别进行了仿真分析。通过对比各方法的性能指标和相应的输出功率波形图,验证了所提出的双模糊控制法是一种比传统方法更优的MPPT控制方法。

Application of double fuzzy control in MPPT of grid-connected photovoltaic generation system

The double fuzzy control is proposed for the MPPT(Maximum Power Point Tracking) of grid connected photovoltaic generation system,which combines asymmetric fuzzy MPPT and fuzzy PID together.The conventional method such as perturbation-observation is replaced by the asymmetric fuzzy control in the reference voltage setting section and the general PID control is replaced by the fuzzy PID control in the actual-reference voltage deviation elimination section.Four MPPT performance indexes are proposed: tracing time when environment changes slowly,power output of photovoltaic array,steady-state power fluctuation,and power output of photovoltaic array when environment changes greatly.Four cases are designed and five control methods are respectively simulated in the environment of MATLAB / Simulink.The comparison of the indexes of MPPT performance and the waveform of output power verifies that,the proposed double fuzzy control method is better than the traditional methods.