PROJECT TITLE :

Diagnosis of single-phase open-line fault inthree-phase PWM rectifier with LCL filter - 2016

ABSTRACT:

In this study, the transient process when the one-part open-line fault (SPOLF) occurs within the three-phase AC-DC pulse width modulation rectifier with LCL filter (LCL-PWMR) is theoretically analysed for the first time and also the corresponding diagnosis theme is proposed. 1st, the equivalent circuit of the LCL-PWMR is built and also the detected part voltage (DPV) detected by the three-section grid voltage sensors underneath fault conditions are derived in s-domain. The result shows that the DPV within the open-line part isn't equal to zero, whereas consists of a elementary component and a resonant element with specific frequency. Furthermore, a diagnosis scheme for the SPOLF primarily based on a pair of-order band-pass filter (BPF) connected in series with enhanced phase-locked loop (EPLL) is proposed. BPF is used to eliminate the basic element of the sum of three-part DPVs and EPLL to estimate the amplitude of resonant element. Then the SPOLF can be detected when the amplitude of resonant part is beyond the allowed threshold. Furthermore, the adaptability of the proposed diagnosis theme for the system with completely different rated power is verified theoretically. Detailed simulations tests based mostly on Matlab/Simulink software and experimental tests are applied to demonstrate the validity of the theoretical analysis and feasibility of the proposed diagnosis theme.