Baker SKF Demo Presentation 09112011-Rom

October 30, 2007 SKF Group Slide 0


Cuprins

Linia de instrumente SKF Baker SKFDe ce trebuie efectuata o analiza statica si dinamica a motoarelor electrice

Discutie asupra izolatiei unui motor electric sicaracteristicile dielectricului

Evidentierea modului in care motoarele electrice se defecteaza

Solutii tehnice statice (in atelier) pentru determinareastariid e functionare a izolatiei si circuti motorului electric

Solutii tehnice dinamice (in functionare) pentrudeterminarea calitatii alimentarii, sarcina si problemelemecanice


Exemple de echipamente SKF pentru managementul motoarelorelectrice in scopuri predictive si asigurarea calitatii in exploatare

SKF Portable Dynamic Motor Analyzer

Exp 4000

Static Motor Analyzer

AWAIV

SKF On-line Motor Analysis System

NetEP


De ce ar trebui facuta analiza statica sidinamica la motoare electrice


Salvari de costuri

Reducerea opririlor accidentale

Indicarea cauzei defectului

Salvari de costuri cu energia

Analiza: Volt Frequency Detection:

Asigurarea calitatii motoarelor

Reducerea timpului de evaluare a starii de functionare


Motor

MCC

Load

Analiza completa a sistemului


Motor

MCC

Load

1. frequency 2. speed

3. Torque4. Power

5. Voltage

6. Current

Lantul de evenimente


Caracteristica de izolatie a motoarelorelectrice

Cum se defecteaza motoarele electrice side ce ?

Intrebarea nu este DACA motorul se va

defecta ci CAND se va defecta!


Incidenta modurilor de defectare la motoareleelectrice:

Bearing

44%

Rotor

8%

Other

22%

Stator

26%

Bearing

41%

Other

14% Rotor

9%

Stator

36%

IEEE Study EPRI Study


Cauzele defectarii motoarelor electrice:Studiu IEEE

0%

20%

40%

60%

80%

100%

Bearing Winding

Electrical Fault

Mechanical Breakage

Insulation Breakdown

Overheating


Etapele tipice defectarii unui motor electric datoratescurtcircuitului electric

(1) Izolatia electrica a unui motor nou este foarte bune

(2) Motorul este supus uneiimbatraniri naturale

Termic

Chimic

Mecanic

(3) Capacitatea de izolatie Spira-Spira scade sub nivelul rezistentei la tensiunea si curentul de functionare

Arcuri electrice de strapungere apar la pornire


(4) Insulatia incepe sa se strapungadin ce in ce mai des

(5) Rezistenta de izolatie Spira-Spira scade sub tensiunea de functionare

Motorul intrerupe la supracurent

(6) Spirele strapunse cauzeaza o incarcare mai mare cu curent a infasuratorii temperatura ridicata , curent absorbit de circa 16-20 orimai mare decat sarcina nominala

(7) Defectare rapida (deobicei de ordinul minutelor)

Etapele tipice defectarii unui motor electric datorate scurtcircuitului electric


Modul de defectare: scurtcircuit Spira-Spira

80% dintre defectele motoarelor electrice incep datoritascurtcircuitului inspre spire

Majoritatea se vor defecta prin scurtcircuit la carcasa insaoriginea defectului ramane scurtcircuitul Spira-Spira

Sursa: General Electric Paper


Cauzele pentru care cele mai dese defecte sutndatorate scurtcircuitului Spira-Spira

Spira este cea mai slaba izolatie din circuitul electric al motorului

Depunerile si coroziunea chimica distrug in timp izolatia

Miscarile dintre spire (la pornire) distrug izolatia (o crapa)

D.E. Crawford\General Electric


Solutii tehnice pentru determinarea starii de functionare a izolatiei circuitului motoarelorelectrice


Teste complete de sarcina electrica

Echipamentul BAKER Surge Test este unica metoda de efectuare a unui set complet de teste electrice, in conformitate cu standardele IEEE ce permit tehnicianului saprevada starea de functionare a motorului electric.


1. Surge Test

Testarea permite descoperirea Izolatiei slabite (PPM, QA, TS)

Spira-Spira

Faza-Faza

Bobina - Bobina

In atelier: Lista de defecte posibile

Izolatie slabita Spira-Spira, Faza-Faza, Bobina Bobina (QA, TS, PPM)

Bobine inversate (QA)

Scurtcircuit intre spire (QA,)

Numar diferit de spire in bobine (QA)

Dimensiune diferita a litei de bobinare a bobinelor (QA)

Izolatie defecta infasuratoare - carcasa(QA)


Surge ring


Izolatie defecta Spira-Spira


432-1992 IEEE guide for insulation maintenance for rotating electric machinery (5 hp to less than 10 000 hp)IEEE Guide for Insulation Maintenance for Rotating Electric Machinery (5 hp to less than 10,000 hp)

ScopeThis insulation maintenance guide is applicable to industrial air-cooled rotating electric machines rated from 5 hp to 10 000 hp. The procedures detailed herein may also be useful for other types of machines.

7.4 Interturn Insulation Tests

Film insulation usually provides high dielectric strength but, in many cases, the interturn insulation on motor coils is porous in nature. Fibrous insulation effectively provides a physical separation of the turns of the order of 0.010 to 0.025 in (0.250.635 mm) for motors, and the electric strength between the turns is essentially provided by the insulating value of the gas (air, hydrogen, etc.) contained between these bers. Micaceousinsulations are commonly used in high-voltage machines.

To provide a useful service in checking the adequacy of the insulation between turns, the test level selected must be greater than the minimum sparking potential of the air at the minimum permissible spacing. The test potential will often, therefore, be several times normal operating volts per turn. A test of about 500 V rms per turn is considered average for a new machine, while for maintenance tests potentials of one-half to two-thirds of the new coil turn test, eight to ten times normal operating volts per turn, are usually considered adequate to provide insurance from the possibilities of marginal insulation and contains allowance for switching transients and for surges likely to be encountered in service.

The normal operating volts per turn are often up to about 30 V for motors, while turbine and water-wheel generators are substantially above that value. The test methods used include forms of surge comparison tests. A steep-front surge is applied to all or part of a winding, or by induction to individual coils within a winding. The resultant waveforms are viewed on an oscilloscope screen and interpretation of the patterns or amplitudes permits detection of short-circuited turns. The surge comparison test applied directly to the winding terminals is limited, in the case of windings consisting of many coils in series, by the magnitude of the voltage that can be applied to the ground insulation without exceeding its specified test voltage. This limitation can be overcome by placing a surge coil in the bore over the coil to be tested and by applying directly into it a voltage appropriate to the induced volts per turn required in the stator coil. For additional

information on procedures and requirements for interturn insulation tests, see IEEE Std 522-1992 [10]. See [B14] for detailed information on surge comparison testing.


IEEE Standard for Petroleum and Chemical Industry Severe Duty Totally Enclosed Fan-Cooled (TEFC)Squirrel Cage Induction Motors Up to and Including 370 kW (500 hp)

d) The 2300 V and 4000 V designs shall use vacuum-pressure-impregnated form windings, capable of withstanding a voltage surge of 3.5 per unit at a rise time of 0.1 s to 0.2 s and of 5 per unit at a rise time of 1.2 s or longer. (One per unit equals 0.8165 V L-L .)The test method and instrumentation used shall be per IEEE Std 522-1992.When specified by the purchaser, this requirement shall also apply to form windings supplied for voltages 575 V and below on motors rated above 150 kW (200 hp).


2. Teste electrice generale

2.1 Rezistenta infasuratorii (PPM, QA, TS)

2.2 Masurarea rezistentei cu Mega-Ohm (PPM, TS)

2.3 Testul de polarizare a dielectricului (PPM, QA)

2.4 Teste la niveluri crescute de tensiune (PPM, QA, TS)


2.1 Probleme legate de masurarea rezistenteiinfasuratorii

Echilibrul intre infasuratorile fazelor (PPM, QA, TS) Dezechilibru intre faze (QA)

Diametrul litei de bobinare (QA)

Conexiuni cu rezistenta electrica marita (PPM, TS, QA)

Scurtcircuit bobine (TS, QA, PPM)

Bobine cu defecte de conectare (TS, QA,)


2.2 Meg-Ohm Test

Meg-Ohm-Meter Permite:

Determinarea faptului ca motorul da la masa. (TS)

Motor murdar (mecanic, chimc) scurgeri de curent (PPM)

Evolutia in timp (PPM)

Meg-Ohm-Meter Determina:

Daca motorul este buna de functionare

Defecte de bobinare

Infasuratori slabite eletric

Defecte intre faze


2.3 Index de polarizare, Teste de absorbtie a dielectricului

Poate detecta- Izolatie deteriorata intre spira si carcasa (PPM, QA)

Uscata / casanta, dura, sau exfoliata la carcasa (PPM, QA)

Umezeala si contaminare


2.4 Teste la niveluri crescute de tensiune

Poate descopri Izolatie slabita la carcasa (PPM, QA, TS)

Probleme de slabire a conexiunilor (PPM, QA, TS)


Case Study: Weak Insulation Turn - Turn

Low Voltage Tests Show all good



Low Voltage Tests Show all good



Surge test is the only test capable of finding weak insulation turn to turn

Phase 1 & 2 are good



Phase 3 shows weak insulation Turn Turn at about 1,000 volts.

Now this is not a Turn Turn Short but this will be within weeks !

If it was the winding resistance would be unbalanced and it is not

No other technology can find this fault


Case Study: Contamination in J-Box

Motor 7200 volt

1000 Hp

3600 RPM Motor


Case Study: Contamination of J-Box



Results after the J-Box was cleaned


Summary of Contamination Case Study

Only by elevating the voltage above operating voltage did we see a problem

Voltage spikes could track and cause a failure


Case Study: Step Voltage Test at Higher Voltage Found Unstable Ground Wall Insulation

4160 Volt Motor

300 HP

1770 speed

Tested 4 identical motors at a power plant



Last step at 8,960 Volts shows unstable ground wall insulation

The step test allows the operator to see and trend the current leakage


Solutie dinamica pentru determinareaputerii, sarcinii si a problemelor mecaniceale motoarelor electrice


EXP3000 and EXP3000R

Echipamente mobile Echipamente permanente


Safety and Connecting:Low Voltage (Less than 600V)

Motor

MCC

Load

Breaker

Step one: Running motor

Step two: STOP motor

Step three: Connect MPM

Step four: Run and test

Step five: STOP motor

Step six: Disconnect MPM

Exp


Safety and Connecting: Medium and High Voltage (More than 600V) Connect into Secondary Pts and Cts

Motor

Load

CTs

Breaker

Step one: Motor is running

Step two: Connect Explorer CTs

Step three: Connect Explorer PTs

Explorer

PTs


Motor

CTs

Breaker

PTs

EP

Explorer

First Energy

RC Pump

1 of 700+ EPs at one customer

Acquire Data: Safe, Fast & Easy W/ EP-1


SKF Online Motor Monitoring NetEP - Overview

NetEP is a fully automated, network connected, electrical motor monitoring system. It continuously collects data on the health and performance of electric motors.

The NetEP is a permanently installed system. Permanent voltage and current sense connections are required for each motor.

The NetEP monitors over 40 electrical parameters of electric motors and compares the results to limits, displaying alerts if limits have been exceeded.

The NetEP can be configured, monitored and operated from any network connection.


SKF Online Motor Monitoring NetEP - Overview

NetEP Networked Electrical Processor

Up to 32 motors (96 CTs) 5A to 2000A

Calibrated, from Baker

Up to 150 CT signal runs on CAT 5 cable

25 KHz signal acquisition

Up to 7 different voltage busses Up to 1000V direct input, or PTs.

Line to line, line to neutral, External Disconnect Required

MCC mounted box 20 x 30 x 8, ~ 65 lbs

CAT III, NEMA 12 Enclosure

LAN and AC power (110V 240V) required

Computers for data storage and Network based monitoring Provided by customer (IT compatibility)

Test all 32 motors every 10 sec (Basic Motor Monitoring)


Power Quality Analysis

PQ Capabilities Voltage and Current level, unbalance distortions

Kvars, KVA, KWs, Power factor, Crest factor, Harmonic bar chart ect.


Faults Explorer & AWA will Identify

Power Quality

Poorly performing Transformers

Short, medium, long, range trip settings

Connection issues (Junction Box, In motor)

Lead Line Insulation deterioration

Turn-Turn, Phase-Phase, Coil-Coil insulation weakness

Ground Wall Insulation

Weakness Dirt Moisture Dry Rotted, Brittle CracksMotor Circuit

TurnTurn Shorts, Opens Reversed Coils Phase Unbalanced (turn count) Phase Unbalanced (wire size)Rotor

Cracked Bars Poor Welds Broken Bars Eccentricity (Dynamic, Static)

Loading Issues

Over load ProcessMechanical

Bearing faults Miss Alignment Fan Unbalances Belt frequencies Worn Impellers Gear Mesh FrequenciesVFD

Power Quality Shorted IGBTs Feed Back loop Process Information Tuning / Set up Soft Start

Tuning / Set up Trouble shootingEct.

STATIC

DINAMIC

DINAMIC


Motor Overheating

I2R Losses Motor Currents

100% rated Current 100% rated Temperature

110% rated Current 121% rated Temperature


Voltage quality NEMA derating

Voltage Unbalance & Harmonic Distortions


Test station 300 hp 3570 rpm

Eff. s.f. =% NEMA derating

% Load

Effective s.f.


Temperature (C)

Full Load 1.15 SF 1.25 SF

49 64 77

56 75 91

75 102 128

64 80 94

69 89 106

Horsepower

10

20

50

100

200

* Courtesy U S Motors

Motor Performance:Service Factor and Temperature


Effective s.f.

Pulp & Paper Industry:

Operating RMS values

Voltage Level 658.2 V 99.7%

Current Level 378.4 A 91.4%

Load Level 312.6 kW 78.1%

All OK?Voltage Unbalance 3.66%

Voltage Distortion 9.80%

NEMA derating % 0.6

Eff. s.f. 1.28


Power Quality Analysis

Importance

Poor power quality causes increase heat

For every ten degrees rise in temperature the life of the motor is reduced in half.


Fan 1 hp 1740 rpm

Motor Condition:Broken Rotorbar


Torque Analysis

Great tool for Separating between electrical and mechanical issues (solve fighting between mechanics and Electricians) Reason the load is what causes more or less torque from the motor

If a torque signature looks out of the ordinary the problem is most likely in the load


4160V submersible pump

Torque Signature:


Mechanical FFT Analysis

Diagnose mechanical issues from the MCC

Bearing

Outer Race

Inner Race

Cage fr.

Fan Unbalance

Ect.


VFD: Variable Frequency Drive Analysis

Benefits

Tune in drive

Load analysis

Faulty IGBTS

Feed back loop issues


Transient Analysis

Set up short medium and long range trip settings

Set up Soft Starts

Diagnose Pump and Fan issues

Worn impellers

Binding pumps

Power Issues

Rotor Issues


Continuous Monitoring SoftwareExcellent Trouble Shooting Tool


Organizations Backing Testing

IEEE 522

IEC 34-15

NEMA MG1

NFPA 70B

EASA


Easy Automatic Analysis of Results


Sumarul prezentarii

Analiza dinamica a motoarelor electrice asigura informatiidespre calitatea puterii, sarcinii, defectelor electrice la motorulelectric / MCC / masina antrenata.

Analiza statica a motoarelor electrice asigura masurareaintegritatii sistemului de izolatie a motorului si a circuitului sauelectric.

Impreuna cele doua metode asigura metode complementare de indentificare a satrii de functionare a motoarelor electrice , diagnoza precisa a defectelor si prevad / prezic eliminareadefectelor.

Cresterea calitatii inspectiei motoarelor electrice concura la eliminarea defectelor si la predictia lor. Eliminarea defetelor: pentru a nu trimite in camp motoare defecte. Predictiadefectelor: masuri pentru evaluarea starii de functionare sieliminarea opririor accidentale.

Questions?

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Baker SKF Demo Presentation 09112011-Rom

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