Tehnički vjesnik, Vol. 27 No. 3, 2020.
Izvorni znanstveni članak
https://doi.org/10.17559/TV-20190904105201
Diagnosis and Location of Open-Circuit Fault in Modular Multilevel Converters Based on High-order Harmonic Analysis
Longzhang Ke
; School of Information Science and Engineering, Wuhan University of Science and Technology, Wuhan 430081, China; School of Electromechanical and Automobile Engineering, Huanggang Normal University, Huanggang 438000, China
Zhenxing Liu
; School of Information Science and Engineering, Wuhan University of Science and Technology, Wuhan 430081, China
Yong Zhang
; School of Information Science and Engineering, Wuhan University of Science and Technology, Wuhan 430081, China
Sažetak
Open-Circuit faults of Submodules (SMs) are the most common fault type of modular multilevel converter (MMC). Thus, in order to improve the reliability of MMC, it is very important to detect and locate faulty MMC SMs. In this paper, a new fault diagnosis and location method based on high-order harmonic analysis of the bridge arm voltage is proposed, and the characteristics of SM open-circuit faults are analyzed. In the proposed method, faults are detected by comparing the amplitude of the bridge arm voltage at the switching frequency with a variable threshold, and the phase angle of the bridge arm voltage at the switching frequency is used to locate the faulty SM. The proposed method can detect faulty SM with just one voltage sensor per arm bridge. Moreover, this method can effectively avoid misjudgment of a fault detection signal in the normal transient state. Finally, a MMC model was built using a MATLAB/Simulink environment and simulations were conducted. The experimental results show that the proposed method can not only diagnose a SM fault quickly, but can also locate the faulty SM accurately.
Ključne riječi
fault detection and location; high-order harmonic analysis; modular multilevel converter (MMC); open circuit faults
Hrčak ID:
239100
URI
Datum izdavanja:
14.6.2020.
Posjeta: 1.701 *