Variable Forgetting Factor Recursive Least Squales Based Parameter Identification Method for the Equivalent Circuit Model of the Supercapacitor Cell Module

In order to accurately identify the parameters of the equivalent model of supercapacitorcell module in the backup power supply of the pitch system of megawatt wind turbine and to solve the problem that the gain decreases too fast due to the data saturation phenomenon, the three-branch equivalent circuit model for the supercapacitor cell module was established, and a parameter identification method of the equivalent circuit model of supercapacitor cell module based on variable forgetting factor recursive least squares(RLS) was proposed in this paper. Then, the Simulink simulation model was also established for the multi-method parameter identification of supercapacitor cell module, and the simulation and analysis were performed. The comprehensive error in the static self-discharge phase of this new method is 0.19%, which is 6.92% and 0.09% lower than circuit analysis method and segmentation optimization method, respectively. Its comprehensive error in the whole process is 1.22%, which is reduced by 9.5% and 1.6% compared with circuit analysis method and segmentation optimization method, respectively. The results show that the new method has higher identification accuracy than circuit analysis method and segmentation optimization method. © 2021, Electrical Technology Press Co. Ltd. All right reserved.