Abstract
The multi-level inverter is widely used in high-power and high-voltage applications. Multi-level inverters use a large number of switches for high power conversion, resulting in increased system's fault probability. To ensure stable operation of the system, several fault diagnosis methods have been carried out by researchers. In this article, a fault diagnostic system in a multi-level inverter using wavelet modulus maxima is developed. The working situation of the power devices of a five-level diode-clamped multi-level inverter drive system under an open-circuit fault is analyzed through MATLAB (The MathWorks, Natick, Massachusetts, USA) simulation. The wavelet modulus maxima of output phase voltages are used to detect faulty phase (leg), and wavelet modulus maxima of DC bus currents are used to detect fault type and fault switch. Wavelet analysis is used for feature extraction, which can be used as input to the expert system to develop a fault identifier. The open-circuit fault on the five-level diode-clamped multi-level inverter of power devices is carried out experimentally. The experimental prototype is developed to validate the fault analysis with simulation results.
NOMENCLATURE
a | = | scaling parameter |
b | = | shifting parameter |
cn | = | approximate coefficient |
dn | = | detail coefficient |
f(t) | = | signal to be analyzed in time domain |
= | Fourier transform of signal f(t) | |
Wmaxf(t) | = | wavelet modulus maxima of signal f(t) |
Wf(a, b) | = | wavelet transform of signal f(t) |
α | = | Lipschitz exponent |
ψ(t) | = | wavelet function |
ψa, b(t) | = | translated and scaled wavelet function |
Additional information
Notes on contributors
Rashmi A. Keswani
Rashmi A. Keswani received her B.E. in electrical engineering from Visvesvaraya Regional College of Engineering, Nagpur, India, in 2001 and her M. Tech. (by research) in electrical engineering from Visvesvaraya National Institute of Technology, Nagpur, India, in 2008. She is working as an assistant professor in the Department of Electrical Engineering, Priyadarshini College of Engineering, Nagpur (India). She is currently working toward her Ph.D. Her research interests include multi-level converters and electric drives.
Hiralal M. Suryawanshi
Hiralal M. Suryawanshi received his B.E. in electrical engineering from Walchand College of Engineering, Sangli, India, in 1988 and his M.E. in electrical engineering from Indian Institute of Science, Bangalore, in 1994. He was awarded his Ph.D. by Nagpur University, Nagpur (India), in 1999. He is currently Dean (R&C), Visvesvaraya National Institute of Technology, Nagpur, (India) and a professor in the Department of Electrical Engineering. He received the Fellow of Indian National Academy of Engineering (FNAE) in 2012 for outstanding research. He is a senior member of IEEE (USA) and a fellow of IETE (India). His research interest is in power electronics, emphasising developmental work in the areas of resonant converters, power factor correction, active power filters, FACTS devices, multi-level converters, high-frequency electronic ballast, and electric drives.
Mohan M. Renge
Mohan M. Renge received his M.E. in electrical engineering from Walchand College of Engineering, Sangli, India, in 1988 and his Ph.D. from Visvesvaraya National Institute of Technology, Nagpur (India), in 2010. He is working as a professor in the Department of Electrical Engineering, Shri Ramdeobaba College of Engineering and Management, Nagpur (India). He is member of ISTE (India) and IEEE. His research interests include electric drives, multi-level converters, FACTS devices, and solar system interfacing.