The Transactions of the Korean Institute of Power Electronics (전력전자학회논문지)

The Korean Institute of Power Electronics (전력전자학회)
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An Adaptive Digital Notch Filter for Stabilization of Single-Phase Grid-Connected Inverters With LCL Filter

LCL 필터가 결합된 단상 계통연계형 인버터의 안정화를 위한 적응형 디지털 노치 필터

  • Heo, Jin-Yong (Dept. of Electrical Engineering, Pukyong Nat'l University) ;
  • Kim, Hak-Soo (Dept. of Electrical Engineering, Pukyong Nat'l University) ;
  • Nho, Eui-Cheol (Dept. of Electrical Engineering, Pukyong Nat'l University)
  • Received : 2021.03.02
  • Accepted : 2021.04.29
  • Published : 2021.10.20
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Abstract

Even though the LCL filters have superior harmonic attenuation ability to L filters, stability has always been an issue. The system could be unstable because of the resonance phenomenon, especially when digital controller is used. Adding a notch filter to the compensator is one approach to solve the problem. Resonance phenomenon can be inhibited by aligning notch frequency to system resonance frequency. However, resonance frequency variation can be obtained because the actual system has a nonstationary characteristic. Therefore, the system could be unstable, where the system parameters are changed when the conventional notch filter is used. An adaptive digital notch filter that stabilizes the system even system parameters are changed. Simulation and experiment results are provided to verify the validity of the proposed adaptive filter.

Keywords

Acknowledgement

본 연구는 산업통상자원부(MOTIE)와 한국에너지기술평가원(KETEP)의 지원을 받아 수행한 연구과제입니다. (No. 20194030202310)

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