Online inverter fault diagnosis of buck converter bldc motor combinations To Get this projects Call : 9566355386 / 99625 88976 Visit : www.lemenizinfotech.com / www.ieeemaster.com Mail : projects@lemenizinfotech.com

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Online Inverter Fault Diagnosis of Buck-
Converter BLDC Motor Combinations
Abstract
Introduction:
Magnetically suspended control moment gyro (MSCMG) is
considered to be the key actuators for the attitude control of
space stations, satellites, etc. It has the character of high
precision, large moment, and long life owing to the zero friction
and enhanced damping of high-speed rotor. Since the
operational environment in vacuum is harsh, high reliability and
long-life operating ability are required. Normally, the high-
speed motor in MSCMG is operating at a constant high speed to
supply angular momentum for the high-speed rotor system. The
reliability of the motor drives is one of the most important
factors to guarantee the safe, continuous, and high performance
operation under even some accidents or faults. The research
mentioned that about 38% of the motor failures are found in the
power inverter and most of faults are occurred to the power
switches. Generally, a fault-tolerant control (FTC) system is
composed of fault detection, identification, and remedial actions.
The fault detection and identification considered as fault
diagnosis which is the basic and important part in FTC system

2. Do Your Projects With Domain Experts…
Copyright © 2015 LeMeniz Infotech. All rights reserved
LeMeniz Infotech
36, 100 Feet Road, Natesan Nagar, Near Indira Gandhi Statue,
Pondicherry-605 005.
Call: 0413-4205444, +91 9566355386, 99625 88976.
Web : www.lemenizinfotech.com / www.ieeemaster.com
Mail : projects@lemenizinfotech.com
can detect the fault and determine the fault type and location.
Thus, online fault diagnosis of the power inverter is important
for MSCMG to ensure the continuous operating ability even in
the faulty state.
Existing system:
The switching devices have been replaced by an ideally
switched voltage source. This is indicated by the multiplication
of Ue with the switching variable u ∈ {0, 1}. An additional
resistance RL has been added to the model in order to take into
account the ohmic resistence of the coil windings. The motor
has been modeled by an inductance LM with ohmic resistance
RM and electromagnetic voltage source ωKE.
Proposed system:
This paper proposes a model-based and low-cost switch
fault diagnosis method for motor inverter composed of a buck
converter and a three-phase full bridge. Based on the analysis of
the faulty operating state in closed-loop control system, the
residual signals of the voltage observers and the measurements
are extracted to diagnose the inverter fault. The effect of
nonideal back electromotive force (EMF) caused by practical
reasons in production on the estimated voltage is taken into
account in the proposed voltage observer. The method can detect

3. Do Your Projects With Domain Experts…
Copyright © 2015 LeMeniz Infotech. All rights reserved
LeMeniz Infotech
36, 100 Feet Road, Natesan Nagar, Near Indira Gandhi Statue,
Pondicherry-605 005.
Call: 0413-4205444, +91 9566355386, 99625 88976.
Web : www.lemenizinfotech.com / www.ieeemaster.com
Mail : projects@lemenizinfotech.com
and identify both open-circuit and short circuit faults fast and
exactly with reduced hardware. The faults in buck converter and
three-phase full bridge can be distinguished in real time.
Meanwhile, protection measures are carried out to prevent the
system from secondary fault.
Applications:
 BLDC drives

4. Do Your Projects With Domain Experts…
Copyright © 2015 LeMeniz Infotech. All rights reserved
LeMeniz Infotech
36, 100 Feet Road, Natesan Nagar, Near Indira Gandhi Statue,
Pondicherry-605 005.
Call: 0413-4205444, +91 9566355386, 99625 88976.
Web : www.lemenizinfotech.com / www.ieeemaster.com
Mail : projects@lemenizinfotech.com
Block diagram:
Tools and software used:
 MPLAB – microcontroller programming.
 ORCAD – circuit layout.
MATLAB/Simulink – Simulation.
INPUT
DC supply
Buck
converter
Protective
circuit
3 phase
inverter
BLDC
motor
BUFFER circuit
5VDC
PIC controller circuit
OPTO coupler circuit 3 phase gate
driver circuit
12 V
DC
12 V
DC