Authors :
Udeme Idem; Adeola Abiola Adebayo; Ayodeji James Bamisaye
Volume/Issue :
Volume 8 - 2023, Issue 7 - July
Google Scholar :
https://bit.ly/3TmGbDi
Scribd :
https://tinyurl.com/2x676xp2
DOI :
https://doi.org/10.5281/zenodo.8186027
Abstract :
Induction motors are the prime movers in
industries that drive all the processes and equipment like
heavy-duty gear boxes and mills used for production. A
slip ring induction motor is an asynchronous motor in
which the speed it operates is not equal to the synchronous
speed of the rotor. Although they are very efficient and
robust, there are many factors like poor working
conditions, heavy operating duty, Poor power supply, etc.,
that can cause failure in the motor operation. This paper
examines different causes of Electrical failures of Slip ring
induction motors. We ran diagnostics tests on three fault
zones of the motor, viz, the Insulation, Stator, and Rotor
using MCE Max Software tester which is a motor circuit
evaluator. Analyzing parameters like Resistive Imbalance
(RI), Inductive Imbalances (II) etc. which result lead to
excess heat generation that causes cracking, and abrasion
on the insulation are examined. We also looked at
Capacitance to ground (CTG) which shows the level of
contamination buildup on the surface of the windings. All
11KV slip ring induction motors irrespective of the type,
had a strong positive and negative correlation association
between fault indicators on the Motors. This paper did a
detailed analysis on the impact of these fault indicators on
the overall motor and insulation health and proposed the
use of periodic overhaul intensive maintenance plan to
combat the negative impact of these fault indicators.
Finally, a high CTG, RI, and II, leads to a low polarization
index (PI), Low Dielectric Absorption (DA), and a very
low Resistance to Ground RTG; showing very poor
overall Stator, Rotor, and Insulation health. With
periodic intensive overhaul maintenance (PIOM), the
ingress of both carbon dust, condensation, environmental
contamination and other undesirable build-ups on the
windings can be reduced, allowing effective and proper
cooling of the drives.
Keywords :
Resistive Imbalance, Inductive Imbalance, Capacitance to Ground, Polarization Index, Dielectric Absorption, Insulation, Resistance to Ground.
Induction motors are the prime movers in
industries that drive all the processes and equipment like
heavy-duty gear boxes and mills used for production. A
slip ring induction motor is an asynchronous motor in
which the speed it operates is not equal to the synchronous
speed of the rotor. Although they are very efficient and
robust, there are many factors like poor working
conditions, heavy operating duty, Poor power supply, etc.,
that can cause failure in the motor operation. This paper
examines different causes of Electrical failures of Slip ring
induction motors. We ran diagnostics tests on three fault
zones of the motor, viz, the Insulation, Stator, and Rotor
using MCE Max Software tester which is a motor circuit
evaluator. Analyzing parameters like Resistive Imbalance
(RI), Inductive Imbalances (II) etc. which result lead to
excess heat generation that causes cracking, and abrasion
on the insulation are examined. We also looked at
Capacitance to ground (CTG) which shows the level of
contamination buildup on the surface of the windings. All
11KV slip ring induction motors irrespective of the type,
had a strong positive and negative correlation association
between fault indicators on the Motors. This paper did a
detailed analysis on the impact of these fault indicators on
the overall motor and insulation health and proposed the
use of periodic overhaul intensive maintenance plan to
combat the negative impact of these fault indicators.
Finally, a high CTG, RI, and II, leads to a low polarization
index (PI), Low Dielectric Absorption (DA), and a very
low Resistance to Ground RTG; showing very poor
overall Stator, Rotor, and Insulation health. With
periodic intensive overhaul maintenance (PIOM), the
ingress of both carbon dust, condensation, environmental
contamination and other undesirable build-ups on the
windings can be reduced, allowing effective and proper
cooling of the drives.
Keywords :
Resistive Imbalance, Inductive Imbalance, Capacitance to Ground, Polarization Index, Dielectric Absorption, Insulation, Resistance to Ground.
