Journal of Shanghai Jiao Tong University ›› 2022, Vol. 56 ›› Issue (6): 693-700.doi: 10.16183/j.cnki.jsjtu.2021.515

Special Issue: 《上海交通大学学报》“新型电力系统与综合能源”专题(2022年1~6月)

• New Type Power System and the Integrated Energy •     Next Articles

An Identification Method for DC-Link Capacitor Capacitance of Grid Connected Inverter

ZHU Chenghao1, WANG Han1, SUN Guoqi2, WEI Xiaobin2, WANG Fuwen3, CAI Xu1()   

  1. 1. Key Laboratory of Control of Power Transmission and Conversion of the Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240
    2. Shandong Deyou Electric Co., Ltd., Zibo 255035, Shandong, China
    3. Shaanxi Luneng Jingbian Wind Power Co., Ltd., Xi’an 718500, China
  • Received:2021-12-15 Online:2022-06-28 Published:2022-07-04
  • Contact: CAI Xu


DC-link for the capacitor is one of the most vulnerable components of the grid connected converter, whose capacitance identification will help to improve the system reliability by finding and replacing the aging capacitor in time. An identification method for the DC-link capacitor capacitance of the grid connected inverter based on pre-charging circuit is proposed. By analyzing the relationship between the capacitance and the charging current, charging voltage during pre-charging process, and combining the historical operating data, the set of capacitance state feature vector is built. The support vector regression (SVR) model is trained and the regression prediction relationship between the state value and the capacitance is set. The model is optimized by using the particle swarm optimization (PSO) algorithm, which can be used for capacitance identification of the DC-link capacitor. Simulation and experiments results show that the proposed method can implement the accurate capacitance identification of the DC-link capacitor of the grid connected inverter, with an identification error of less than 0.95%. This method does not need to add hardware circuit and change the control algorithm, and has a certain practical value.

Key words: grid connected inverter, DC-link capacitor, capacitance identification, pre-charging circuit, support vector regression (SVR)

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