DRAFT Specification No……..
lR;eso t;rs
GOVERNMENT OF INDIA
MINISTRY OF RAILWAYS
SPECIFICATION FOR GUIDELINES TO SET-UP THE TEST BED OF TESTING OF REPAIRED/OVERHAULED 3-PHASE TRACTION MOTORS OF WDG4 / WDP4 LOCOMOTIVES.
FEBRUARY 2011
Issued by
Motive Power Directorate
Research, Designs and Standards Organisation
Manak Nagar, Lucknow-226011
1.0 Introduction
ALCO locomotives are rebuilt at DMW/PTA. It has been decided that repairing/ overhauling of traction motors for 4000/4500 hp AC-AC WDG4 and WDP4 locomotives are also to be carried out at DMW/PTA. In view of this test facilities shall be required to verify the characteristic of these repaired /overhauled traction motors. A general guidelines for installation and commissioning of test bed for testing of repaired/overhauled traction motors of WDG4/WDP4 locomotives at DMW/PTA have been framed.
Objectives:
2.1 This guidelines covers the technical requirements for setting-up the test facilities for conducting routine testing of 3-phase traction motor type 1TB2622 and ITB2525 of M/s Siemens make or equivalent Traction motor of other manufacturers used in 3-phase Diesel Electric Locomotives of Indian Railways. The scope of technical requirement of this guidelines covers the design, manufacturing, supply and commissioning of the equipment for test set-up at DMW/PTA for conducting routine testing of the motor. The system should be suitable to deliver 2500V to test the motor. Specified schematics for test set-up in given in Annexure-I.
2.2 The proposed test bed shall be such that the existing set-up shall be suitable for ROUTINE TEST comprising of short duration temperature rise test, No-Load test, short circuit test, vibration test & Noise test etc. as per IEC 60349-2 of above said motors under uncoupled conditions without any modification in the existing ones. The test parameters of already tested motors is given at Annexure-II for reference
2.3 At a latter date, if it is required to upgrade the test bed, for conducting full load test (Part of type test as in IEC) it should be possible to do so by minimum adjustment in the existing set-up and by commissioning of additional equipment along with various interfaces. In that case the test bed shall be comprised of four quadrant active front drive during upgradation for load tests. The test parameters at testing (Part of type test) of already tested motors is given at Annexure-III for reference.
2.4 The equipment required for carrying load test (Part of type test as in IEC) of the motors shall be taken up in 2nd phase after successful completion of the project for conducting routine testing of the motors.
2.5 The offered equipment shall be designed to comply with the latest issues of the appropriate International Electro-technical Commission Standards (IEC) or Indian Standards (BIS) standards. The same may be indicated in the offer.
3.0 Scope of Supply:
3.1 This guidelines defines the supply of transformer and their associated auxiliary equipment / accessories, off-circuit tap changer and earthing bus bars. The successful tenderer shall supply the necessary equipment and undertake the testing and commissioning of the test bed on turnkey basis.
3.1.1 The scope of Transformer include s:
• The tap changer
• The marshalling kiosk
• The Primary phase CTs
• The Primary neutral CTs
• The Secondary neutral CTs
• All multicore / multipair cabling between those items
• All multicore / multipair cabling between other equipment such as WTI’s, cooling pumps and fans.
The Primary and Secondary currents should be indicated with appropriate meters.
3.1.2 The scope will also include the provision of separate Earthing connections to the main tank, each cooler bank, the Primary neutral Earthing connection, co-coordinating rod Earthing connections, the Secondary neutral Earthing connection for the transformer.
3.2 This guidelines also defines the supply of VFD drive suitable for driving the 3-phase Motor to be tested rating upto 1.4MW / 2.5KV. It shall also consist of control desk, from which the control of all the testing parameters can be controlled, monitored / measured and recorded.
3.3 Switchgear Equipment: Since the supplier has to supply the test bed on turnkey basis, the supplier shall supply suitable switchgear equipment for satisfactory operation and protection of the overall system.
3.4 Surface Plates for Traction Motor Test Bed to be supplied by the tenderer.
3.5 Cables and Cable accessories to connect all the equipment under the scope of supply of tenderer. Distance from supply points to the equipment & test plant shall be provided by DMW.
3.6 Instrumentation
· Power Analyzer
· Insulation Tester
· High Voltage Tester
· Multimeter(s)
· Temperature Scanner
· Tachometer with speed sensors
· Vibration Measurement meter
· Noise Level Meter
· DC Current Source
· 1-ph Variac of 28-Amps & Current source of 50 Amps, having voltage, and
current measuring instruments
4.0 Transformer
4.1 References
· IEC 60529: Degrees of Protection Provided by Enclosures
· IS 2026-1: Power transformers: Part 1 (General)
· IS 2026-2: Specification for power transformers: Part II Temperature-rise
· IS 2026-3: Specification for power transformers: Part III Insulation levels and
Dielectric tests
· IS 2026-4: Specification for power transformers: Part IV Terminal markings,
tapings and connections
4.2 Definitions
· CMR - Continuous Maximum Rating – capable of delivering the maximum applied load constantly
· Primary - The high voltage winding of the transformer and any components (e.g. CTs, Bushings) associated with it.
· Secondary - The low voltage winding of the transformer and any component (e.g. CTs, Bushings) associated with it.
4.3 The Input voltage System: The indicative rating/requirement of the transformer proposed for the test-set up is furnished as below. The tenderer may offer its own design to cater to the requirement during in the offer.
System Voltage (available at input supply from SEB): 11 kV
Rated Voltage : 12 kV
• Size of step : 5%
• Nominal position Tap : 3%
• Number of tapping positions : 5%
Rated Frequency : 50 Hz
Design Fault Levels 3ph : 25 kA for 1 Sec
Design Fault Levels Ph-E : 25 kA for 1 Sec
Rated lightning impulse-withstand voltage (peak value) to earth: 95 kV
Minimum Electrical Clearances
Basic electrical clearance (Phase-Earth) : 160-mm
Phase to Phase clearance : 250-mm
Insulation height (Pedestrian access) : 2440-mm
Safety working clearance (vertical & horizontal): 2600-mm
4.4.1 Requirement of the Transformer:
4.4.1 Technical Conditions:
.1 The transformer shall be converter duty with one winding in the primary side & multi-winding phase shifted at secondary, suitable to feed the VFD, required to test the motor.
.2 The transformers shall be suitable for installation outdoors and shall comply with IS- 2026. Cooling shall be type ONAN / OFAF or ONAN / ONAF. The design of accessories shall be coordinated so that the thermal rating of the unit shall not be limited by these accessories.
.3 Transformers under this guidelines shall be suitable for frequency range between 20Hz to 70Hz to test the motor, three phase units with electrically separate Primary and Secondary windings. They shall typically have a combination of natural / forced cooling.
.4 The windings shall be able to withstand without damage the thermal and dynamic effects of external short circuit levels. The transformer shall be designed to ensure that leakage flux does not cause overheating in any part of the transformer. Avoidance of over-fluxing at the most onerous operating conditions, especially on cyclic overloading condition, is essential.
.5 Rated Power: The temperature rises associated with maximum power ratings and overloads for 11.5 kV, suitable voltage to run the motor under test, transformers are expected to be within the limits specified in IS: 2026. The designs submitted should comply with the temperature rise limits specified in IS:2026, Part 2, when operating under ONAN and OFAF (or ONAF) conditions on any tapping position. Control of Voltage shall be done using an off-load tap changer.
.6 The guaranteed losses of transformer shall be stated in the tender. These losses shall also be considered during evaluation of the tender.
.7 Creepage distances shall be a minimum of 25mm per kV at the rated voltage.
4.4.2 General Conditions:
.1 The equipment shall be compliant with IS-2026 Power Transformers where appropriate unless otherwise varied in tender document. Any variations from this Standard shall be listed.
.2 The transformer and all associated components shall be designed to be suitable for use at the defined cyclic rating, without exceeding any defined parameters, at an ambient temperature of 45 degrees C.
.3 The transformer and all the ancillary equipment (e.g. CTs, instruments etc.) forming part of the transformer of similar design shall have been type tested by the manufacturer or testing authority in accordance with the relevant IS or IEC standards before delivery. Copies of the relevant type test certificates shall be submitted with the offer.
.4 The transformer shall be supplied with suitable and sufficient anchorage points (painted yellow) for the attachment of work positioning and fall arrest lanyards for use when working at height.
.5 All labels shall be clearly visible from the normal operating position and shall indicate the function of the component, not merely a reference number. The transformer and all connections shall be capable of operating at any tapping position on load.
.6 Manuals shall be provided which clearly indicate any special considerations and procedures for use, maintenance, trouble shooting etc.
.7 The normal operating condition of transformers on the power system is to maintain the secondary voltage constant for either, variations in load on the secondary winding, or variations in voltage applied to the primary winding. (i.e. to boost the voltage by operating the tap changer).
.9 Tap changers shall provide facilities for remote tap position indication, tap change in progress indication and tap-change raise and lower complete indication.
.10 Cable boxes: The transformer shall have cable boxes at both the primary as well as secondary windings
.11 Open Terminal Bushings: On primary winding unit, the HV terminations shall usually be outdoor bushings, with a smaller bushing insulator for the Primary neutral. The Tenderer must specify the types of bushing to be used. On primary winding unit the primary neutral is not bought out as its insulation level is uniform.
.12 Marshalling Kiosk: The Marshalling Kiosk will provide the point at which all alarms, trips, controls, indications, and CT outputs from the main transformer, the earthing or auxiliary transformer and the pump are terminated and ferruled ready for connection with multi-cores to the relay panels. A tank mounted or cooler support structure mounted weatherproof local marshalling kiosk is required on transformer. Paint finish to be the same as the main transformer.
.13 Cooling System: The arrangement of cooling systems should be normally either ONAN/OFAF or ONAN/ONAF types. Coolers are required with detachable radiators, valves for oil filtering, motors, fans, pumps, and related control gear associated with a forced cooling system.
5.0 Variable Frequency Drive (VFD):
Variable speed AC drive also referred as Variable Frequency Converter (VFC) or Variable Frequency Drive (VFD) or Variable Speed Drive (VSD) is used for converting ac input power into a controlled output variable ac voltage or current of variable frequency of 3-phase Induction motor testing.
Power Converter and Inverter: It shall consist of line side 3-phase uncontrolled bridge rectifier using power diodes / thyristors for AC to DC conversion and the drive shall be based on IGBT technology & the VFD output shall be PWM waveform.
Rating of the Drive: The rating of the drive offered by the tender shall be suitable for future expansion (or excel the test requirement) to load the motor for temperature rise test and evaluating the load characteristic, no-load characteristics & lock rotor test upto 70Hz at different frequency. The method to be followed for testing of the motor shall be as per IEC-60349-2
5.1 Reference for Standards:
5.1.1 The design, manufacture and testing of Inverter Panels for AC Drives shall be carried out as per the latest applicable BIS, International Standard, Indian Electricity Rules, Code of Practices and requirement of Chief Electrical Inspectorate of the State Govt. However, for ready reference some of the Standards are listed below.
· IEEE 519 - Recommended Practice and requirement for harmonic control in electrical power systems.
· IS 1248 - Direct acting indicating analogue electrical measuring instruments and their accessories.
· IS 1885 - Part 7 - Semi Conductor Devices
· IS 1885 - Part 27 - Power Electronics
· IS 3700 - Essential ratings and characteristics of semi conductor devices.
· IS 6619 - Safety code for semi-conductor rectifier equipment.
· IS 13947 - Low voltage switchgear and control gear.
5.2 Requirement of VFD Drive
5.2.1 Technical Requirement: The general requirement of the VFD drive is indicative as below. In case the tenderer proposes different design for the proposed test set up to cater to the requirement the same shall be furnished in the offer.
.1 Closed loop vector control (entire speed range) drive to be used with features as specified:
a. Speed control 0.01%, dynamic 0.2%sec, torque lin. <2%, torque rise time ~2 ms.
b. Starting Torque: 150 %, Frequency stability: +0.1%.
c. Overload: 110% load for 60 seconds. Once in every 10 minutes.
d. The ratio of peak inverse voltage to peak voltage of the drive shall be more than 2.5 (under normal operating conditions).
e. Drive Design temperature: 45 ºC.
f. Speed range: 1 % to 270% of the normal speed of the motor.
.2 AC Output: Current waveform should be approx. sinusoidal to provide step less speed variation for the operation of traction motors.
.3 AC drives should be designed / supplied for an output frequency range of 1Hz to 160Hz.
.4 The efficiency of the drive at rated voltage and load should not be less than 97.5%.
.5 The drive supplied should be with input reactor for reduced harmonics as per IEEE159. VFD module and the input reactor should be of same make.
.6 The Bidder shall provide Type and expected life of DC link capacitors used in the system.
5.2.2 General Requirement
.1 The output current of the drive shall be sized on the basis of full load current of motor. It may need to be oversized to accommodate application requirements such as high starting, overload or accelerating torque. It shall also be able to accelerate the load from zero to full speed under specified voltage and frequency variation.