www.koncar-institut.hr
Electrical rotating machines
diagnostics covers
Electrical Rotating
Machines Diagnostics
The goal of electrical rotating machines diagnostics is to
predict the reliability of the machine and suggest necessary
repair and service. With precise and good testing strategy,
great savings can be accomplished and reliability improved.
Usually machine diagnostics is performed using nondestructive methods onsite.
Laboratory for rotating machines as a part of rotating
machines department in KONČAR – Electrical Engineering
Institute has over thirty years of experience in development,
testing and diagnostics of electrical rotating machines with
the database of few thousand performed testing. Laboratory
is equipped with instruments and tools for onsite testing and
diagnostics of rotating machines.
• visual inspection
• tests and diagnostics
• condition prediction.
Rotating machines
diagnostic is based on
collecting data about
characteristic parameters to
check the performance of the machine. Collected data
are then compared with previous measurements.
Diagnostic measurements should be performed so
that all parts of the machine are covered. Therefore
following groups of tests are done:
• stator tests
• rotor tests
• testing of mechanical parts of the machines
Following diagnostic measurements can be done on all type of LV and HV rotating machines:
• preventive on-line and off-line tests to detect possible failures,
• testing before, during and after the overhaul
Rotating machines
diagnostics enables
• important measuring
values trending
• remaining life time
prediction
• reduce unexpected
failures
• shutdown and
maintenance planning
• increase reliability
• reduce maintenance
costs
• reduce insurance
costs
• reduce capital
overhaul costs
In our laboratory we can perform following tests
On-line testing
• vibration measurement with FFT analysis
• noise measurement
• shaft current and voltage with FFT analysis
• temperature measurement
• motor current signature analysis
• on-line partial discharge measuring
• measuring of voltage, current, power and speed
• leakage flux measurement
Off-line testing
• insulation resistance and polarization index test
• stator and rotor resistance measurement
• rotor and stator capacitance test
• DC hipot test, step voltage test and ramp test
• dissipation (or power) factor test
• dissipation (or power) factor tip-up test
• stator surge comparison test up to 30 kV
• stator core ring flux test and El-Cid
• partial discharge test
• impedance and AC pole drop test
• AC hipot test
• rotor bars test
TG-WFD
system specification
References
Croatia
All Croatian Hydro &
Thermal Power Plants
Sisak & Rijeka Oil
Refineries
Cement Factory
Koromačno
Sugar Factory Viro
Županja & Osijek
JANAF
Inagip off-shore
platforms
Paper Industry Belišće
Steel Factory Sisak
Plc. Fertilizer Company
Kutina
Glass Industry
Shipyard Uljanik Pula
Shipyard 3. Maj
Water Management
Water Distribution Zadar
HPP Trebinje
Nuclear Power Plant Krško
HPP Višegrad
HPP Ožbalt
HPP Bočac
Bosnia and
Herzegovina
Slovenia
KRKA Novo Mesto
HPP Jajce II
Sugar Factory Ormož
HPP Buško Blato
TPP Ljubljana
TPP Kakanj
TPP Brestanica
HPP Jajce
Natron Maglaj
TPP Šoštanj
Coke Plant Lukavac
Montenegro
Macedonia
Steel Factory Zenica
HPP Piva
HPP Peručica
TPP Pljevlja
HPP Tikveš
Our most powerful test:
1. Surge test up to 30 kV
• surge testing is a non-destructive test and detects the early stages of secondary
insulation deterioration
• surge testing will predict motor burn-out due to turn-to-turn or phase-to-phase
shorting.
• extremely small changes in inductance such as shorted turns, incorrect turns count
and incorrect turns placement can easily be detected
• test is performed according to IEEE Std95-2002
2. Ramp test up to 50 kV
• high direct voltage ramp tests incorporates a continuous record of current versus voltage
• sensitive indicator of groundwall cracks and fissures
3. Motor current signature analysis
• proven to be a highly valuable predictive maintenance tool
• detect the common machine fault such as turn to turn shortcut, cracked /broken rotor bars, bearing deterioration etc.
• can be used in conjunction with vibration and thermal analysis to confirm key machinery diagnostic decisions
KONČAR – Electrical Engineering Institute Inc.
Department for Rotating Machines
Josip Polak, dipl. ing.
Fallerovo šetalište 22, 10000 Zagreb, Croatia
Phone: +385 1 3656 291, Fax: +385 1 3666 377
E-mail: jpolak@koncar-institut.hr
Web: www.koncar-institut.hr