8/9/2019 T3S - 31 - Specs_50 MVA_refurbishment
http://slidepdf.com/reader/full/t3s-31-specs50-mvarefurbishment 1/27
SPECIFICATION FOR
REFURBISHMENT OF SHORT-CIRCUIT MOTOR-GENERATOR AND ACCESSORIES
1.0 General
1.1 This specification describes the scope of work as regards the refurbishment of existing 50
MVA short-circuit Laboratory, CPRI, Bangalore.
1.2 It is preferred that the whole work of refurbishment is taken up by a single party. However if
it is not possible, the bidder may clearly state his scope among the five different sub-groups
identified for refurbishment.
1.3 Alternatively the bidder may also quote for entirely new set-up covering the scope of all the
sub groups. In this case, the set-up shall include a new generator in place of spare coils as
in clause 2.7.1 and shall meet the specifications of all the sub-groups.
1.4 The bidders are welcome to inspect the existing set-up in order to get any clarifications
and/or to obtain more details.
2.0 Out line of existing set-up and operation:
2.1 The 50 MVA short-circuit Laboratory, CPRI, Bangalore comprises a motor–generator set
with associated controls and accessories. There are two short-circuit transformers for
stepping down the voltage to required levels. There are three test bays where equipment is
mounted for testing. All the essential controls needed for testing are housed in test control
room. The generator excitation, initiation of short-circuit, test sequencing and test data
acquisition are all executed from control desk. The protection panels (relay) for motor-
generator and some specific operational controls are housed in machine (generator)
building.
2.2 The generator is used as a source for high current in short-circuit laboratory. The generator isthree-phase with 50 MVA short-time rating (0.2 sec) and 5 MVA continuous rating. More
details of the existing generator are given in Annexure-1. The windings are wound in two
sections for each phase with terminals brought out for external connections. The sections
can be connected in either series or parallel. The three-phase terminals can also be
connected either in star or delta. This gives flexibility in choosing full excitation voltages of
3.46, 6.0, 6.92 and 12 kV depending on the test requirements. The generator voltage may
be further stepped down using short-circuit transformers to suit the test requirements.
8/9/2019 T3S - 31 - Specs_50 MVA_refurbishment
http://slidepdf.com/reader/full/t3s-31-specs50-mvarefurbishment 2/27
2.3 The generator is driven by a 750 kW slip-ring induction motor which is used to bring the
generator to full speed. The insertion of rotor resistors in drive motor just before the short-
circuit tests limits its supply current from the grid. The test current (short-circuit current) is
delivered therefore from the generator converted from the stored energy (moment of inertia)
in the rotating mechanical system. A 750 kVA, 550 V DC Generator coupled to the
generator-motor shaft is used as main exciter.
2.4 During testing, the equipment to be tested is mounted in the bay with its incoming terminals
connected to the generator output (often through the short-circuit transformer). A typical
short-circuit test involves initiation of short-circuit by closing a high-speed make switch. The
test parameters like currents & voltages are digitally acquired by transient recording system
through suitable transducers. The test current is terminated either by equipment under test
or back up circuit-breaker depending on the test specification. Since the duration of short-
circuit test is very short (in terms of ms or seconds), the entire test sequence is pre-
programmed in a sequencer. The sequencer gives signal for operation of different devices in
certain sequential order decided by the test engineer. The test engineer at control room
manages the entire test sequence. The Annexure-2 gives the single line diagram of the
existing short-circuit laboratory and general layout of the laboratory.
2.5 The existing set-up is now more than 40 year old. The reliability of some components is
becoming more suspect. The windings of generator, motor, exciter (DC machine) and short-
circuit transformer are very old and there is a concern that they may fail suddenly because
of long term insulation-degradation.
2.6 The main objective of refurbishment of the station is the replacement of aged components/
equipment/system with new one. It also involves augmentation/modernization of the facility
wherever required and desirable to suit present-day requirements of testing.
8/9/2019 T3S - 31 - Specs_50 MVA_refurbishment
http://slidepdf.com/reader/full/t3s-31-specs50-mvarefurbishment 3/27
3.0 Detailed Requirements
Following are the scope of the work in five (5) different sub-groups involved in
refurbishment:
3.1.1 Generator
3.1.1.1 It is proposed to get the coils of the generator wound and stock them. In case of
eventuality, this would help in quickly taking up and completing the rewinding work and
bring down the down-time of the machine considerably.
3.1.1.2 The coils shall be wound with latest methods with all the care. Keeping in view the fact
that the coils are for a short-circuit generator, the coils have to be suitable for repeated
short-circuits resulting in thermal and mechanical stresses which should be withstood by
the windings.
3.1.1.3 There are 72 coils in stator winding. The coils need to be wound with at least class ‘H’
insulation.
3.1.1.4 The generator is a 6–pole machine (synchronous speed of 1000 RPM). These rotor coils
have to be wound with class ‘F’ insulation.
3.1.1.5 The coils shall be suitable for the existing generator in all respects ready for replacement
with reference to area of conductor, construction, end winding design, insulation,
dimension, etc.
3.1.1.6 Existing spare coils of generator are available for inspection and reference.
3.1.1.7 The drawing of the stator and rotor coils is given in annexure-3.
3.1.2 Fly wheel
3.1.2.1 The stored energy in the rotating system of the existing generator is sufficient to give rated
output for 0.2 second. This time is required to be increased to 1.0 second by increasing
moment of inertia (MI) of the rotating mass. Presently we are deriving the output for 1.0
second by super exciting the generator field. There is a considerable drop in frequency
8/9/2019 T3S - 31 - Specs_50 MVA_refurbishment
http://slidepdf.com/reader/full/t3s-31-specs50-mvarefurbishment 4/27
during the tests (although the current magnitude is maintained by impulse excitation). It is
proposed therefore to add flywheel to the existing system in order to maintain the
frequency within the specified limit. Refer annexure 1 for more details.
3.1.2.2 The flywheel shall be suitably designed in order that the generator will be able to deliver
50 MVA at 0.25 power factor for 1.0 second with frequency tolerance of 50 Hz ± 10 %.
3.1.2.3 The supplier has to study the existing conditions of the machine and its capability and
present complete designing of suitable flywheel and its engineering including the mode of
fitting it to existing system. The flywheel shall be mechanically stable and balanced. The
bearings, couplings and other mechanical components have to be suitably designed and
integrated into the existing system. The scope of the work includes design, manufacture,
supply, erection and commissioning of the flywheel system. Any changes in the existing
set-up required to be made like extension of shaft, provision of extra bearings etc., shall
be included in the scope and clearly brought out in the bid.
3.1.3 Excitation system
3.1.3.1 The main exciter of the short-circuit generator is a 750kW, 550V DC generator coupled to
the main shaft which in turn is excited by a pilot exciter. The exciter not only supplies the
no-load excitation but also impulse excitation during short-circuit tests. During the short-
circuit tests (short-time withstand tests), the terminal voltage of short-circuit generator
tends to decrease rapidly, due to high magnitude of test current. This in turn tends to
decrease the test current. The test current needs to be maintained constant for the test
period (typically 1.0 second) using suitable dynamic compensation. This compensation is
provided by the impulse excitation system which has to respond quickly and inject
required higher field current in step with the test current. Unlike automatic excitation
scheme, the compensation is in manually fixed steps (four steps) which is preset
depending on the magnitude of the test current. The current control is therefore coarse
and not precise. It requires considerable empirical effort, sifting through past data to set
the controls for regulating the current within permissible limits. The existing excitation
scheme is given in annexure - 4 and 5.
3.1.3.2 The existing system is proposed to be replaced by static excitation scheme. It shall be
supplied complete with all the necessary accessories including source transformer,
thyristor panel, microprocessor based control, associated software etc. The feed-back
8/9/2019 T3S - 31 - Specs_50 MVA_refurbishment
http://slidepdf.com/reader/full/t3s-31-specs50-mvarefurbishment 5/27
loop shall ensure automatic and dynamic regulation of test current (at any set value upto
full MVA level for set duration). Proposed excitation system shall provide an over
excitation facility upto 10% of the normal excitation with facility of impulse excitation for
suitable compensation of test parameters. The excitation controls and operation shall be
integrated with the existing system.
3.1.3.3 The excitation system shall include suitable provisions so as to supply no load excitation
and effective impulse excitation. The no-load excitation shall allow all the operating
sequence in accordance with the design of the rotor and especially the current level and
excitation duration. The system shall be such that the impulse excitation level will be
limited by the rating of the rotor and not by its own levels. The system shall ensure that all
voltage levels upto 12 kV + 10% are maintained with an accuracy better than 1%. The
generator terminal voltage and the excitation current shall be regulated in order to deliver
the preset reference voltage. The automatic device shall check the current and the
duration of excitation, and shall actuate the suitable protections, if needed. This system,
by its own constraint shall not limit the generator capacity. The impulse excitation system
will have to balance the armature reaction during short-circuits and to allow the machine to
comply with the ratings. The impulse excitation shall ensure that the magnitude of the
current is maintained within the limits specified for the various test requirements – typically
less than +5%. The impulse excitation shall be set in action by the synchronous sequence
processor (or a suitable a PLC) controlling the test sequence. The response of feed-back
system shall be as fast as possible to ensure better regulation of output current.
3.1.3.4 The system shall make stepless variation possible from no load to impulse excitation.
Prior to the test, the ceiling voltage ratio between the applied voltage on the field winding
during impulse excitation and the voltage necessary to maintain the no load rated voltage
shall be set in accordance with the magnitude and the duration of the current.
3.1.3.5 The harmonic contents generated shall be restricted by proper design (say by 12 pulse
rectifier) of the source. The total harmonic distortion(THD) shall be less than 8%.
3.1.3.6 De-excitation equipment shall be provided for rapid de-excitation of the generator field
winding. The function will be actuated either by the synchronous sequence processor or
by the protection system. (The function could be ensured by interchanging the function of
rectifier and inverter). However, an additional device shall connect a field discharge
resistance for rapid de- excitation in case of failure in the bridge power supply leading to
short-circuit of the bridge.
8/9/2019 T3S - 31 - Specs_50 MVA_refurbishment
http://slidepdf.com/reader/full/t3s-31-specs50-mvarefurbishment 6/27
3.1.3.7 The scope of the work includes design, manufacture, supply, erection and commissioning
of the complete excitation system together with all the sub systems.
3.1.4 Motor and Drive
3.1.4.1 The 750 kW slip-ring induction motor which is the prime mover is old and to be replaced.
The controls are outdated. The no-load speed of the machine is less than synchronous
speed of 1000 RPM resulting in less than 50 Hz frequency. It is proposed to be replaced
by a machine with a suitable AC variable frequency /DC drive. The motor and the drive
shall be retrofitted with the provision of all the existing essential features. Additionally, it
shall be designed preferably for 50Hz as well as 60Hz operation. The insulation class shall
be at the least F. The details of the existing motor are given in annexure-6. The scope of
the work includes design, manufacture, supply, retrofit, erection and commissioning of
motor and the suitable drive. An option to provide braking arrangement to the motor may
also be quoted as optional extra (e.g. Regenerative/resistive braking – braking shall be
effective in rapidly bringing down the machine at full speed to halt.) The present timing is
about 50 minutes without braking arrangement. The supplier shall indicate the timing with
braking. All the auxiliaries like source transformer, drive panels and other equipment
required shall be included in the scope of supply. All the rotating machines and its
auxiliaries shall conform in the aspects of design, performance to IS 4722:2001 and IEC
60034 (relevant parts).
3.1.4.2 The manufacturer of the drive shall have at least ten (10) years experience in the
production of this type of equipment with ISO 9000, ISO 14000 and ISO 18000
certification. Since the down time in case of faults is very crucial, it is necessary that a
service centre is available for quick servicing with a cycle time of 24 hours near Bangalore
where this station is situated. All printed circuit boards shall be completely tested and
burned-in before being assembled into the completed drive. The Drive shall be subjected
to a preliminary functional test, minimum one (1) hour burn-in and computerized final test.
The burn-in shall be at 40°C, at full rated load, or cycled load. Drive input power shall be
continuously cycled for maximum stress and thermal variation.
3.1.4.3 In case of AC drive, the drive shall utilize efficient IGBT technology throughout the entire
power and Voltage range. Party must have experience in supplying and commissioning
test benches in India. Reference certificates/Orders to be furnished. The Drive shall be
8/9/2019 T3S - 31 - Specs_50 MVA_refurbishment
http://slidepdf.com/reader/full/t3s-31-specs50-mvarefurbishment 7/27
rated to operate from 3-phase power input at rated voltage ±10 %, 47Hz to 53Hz. The
Drive shall employ a full wave rectifier to prevent input line notching and operate at a
fundamental input power factor of 0.97 at all speeds and loads. The Drive efficiency shall
be 98% or better at full speed and load. Suitable provisions may be made to reduce input
current harmonic content, provide protection from power line transients such as switchingtransients from power-factor correction capacitor and reduce RFI emissions. The over-
voltage trip level shall be a minimum of 30% over nominal, and the under-voltage trip level
shall be a minimum 35% under the nominal voltage. Output voltage and current ratings
shall match the adjustable frequency operating requirements of the standard 3ph, 50Hz,
motors. The drive shall be furnished with suitable enclosure rated for operation at ambient
temperatures between 0° and 40°C with a relative humidity less than 95% and no
condensation allowed.
3.1.4.4 The drive shall conform to IEEE 519 - Harmonic analysis for particular jobsite including
total voltage harmonic distortion and total current distortion. The Drive manufacturer shall
provide calculations, specific to this installation, showing total harmonic current distortion
(TDD), at the Point of Common Coupling. Prior to installation, the Drive manufacturer shall
provide the estimated total harmonic distortion (THD) caused by the Drive. The results
shall be based on a computer aided circuit simulation of the total actual system, with
information obtained from the power provider and the user. The acceptance of this
calculation must be completed prior to the manufacture of the drive. The THD shall not
exceed 8%.
3.1.4.5 The Drive shall be equipped with a front mounted operator control panel (keypad) with
back-lit alphanumeric display and a keypad with keys for Run/Stop, Local/Remote,
Increase/Decrease, reset, menu navigation and parameter select/save. All parameter
names, fault messages, warnings and other information shall be displayed in complete
English words or standard English abbreviations to allow the user to understand what isbeing displayed without the use of a manual or cross-reference table. The keypad is to be
used for local control, for setting all parameters, and for stepping through the displays and
menus. All the necessary parameters shall be able to be displayed. Serial communication
capabilities shall include, but not be limited to, run-stop control; speed set adjustment,
proportional/integral/derivative PID control adjustments, etc. A minimum of 15 field
parameters shall be capable of being monitored. A fiber optic communication port shall
also be provided for personal computer interface. Microsoft Windows®-based software
shall be available for drive setup, diagnostic analysis, monitoring and control. The
8/9/2019 T3S - 31 - Specs_50 MVA_refurbishment
http://slidepdf.com/reader/full/t3s-31-specs50-mvarefurbishment 8/27
software shall provide real time graphical displays of drive performance. Monitors shall be
made available at two locations in the laboratory for supervisory information(Head of
maintenance and head of laboratory)
The drive shall include protection for over-load (motor), Over current , over voltage,Temperature, phase loss ( AC drive) and surge.
3.1.5 Operation and control
3.1.5.1 The existing controls of generator and motor and proposed controls of exciter-drive for
testing shall be integrated. During the tests, the input to the motor is blocked and the test
current is derived from the generator converted from the mechanical energy stored in the
rotating mass. Immediately after the end of test, the generator is to be de-excited and the
supply to the drive motor resumed. The controls needed during tests, like turning on and
off the thyristor to block the supply during short-circuit tests, impulse excitation controls,
de-excitation etc., shall be added to the programmable sequencer. The test sequencing
shall be automated with provision of suitable synchronous sequence
processor/programmable logic controllers (PLC). The manufacturer will preferably use
110V d.c. voltage level for control and automation. The connecting cables to be linked
with other parts of the station will be brought to a plug board and will comply as far as
possible with the above mentioned requirements, including the following but not limited to:
- The excitation and impulse excitation controls.
- The pilot generator signal.
- The protection signals for switching off.
- The interlocking lines coming from the test control room.
- The measurement transmission lines to the test control room
3.1.5.2 The test data is transient in nature and is captured by transducers at the test bay. The
outputs from these transducers are analog. These need to be converted to digital signals
using suitable Data-acquisition system ( DAS) and need to be transferred ( 24 different
signals) to the test control room where it is reproduced for analysis, stored and archived.
The DAS shall have 24 Single ended, isolated inputs. The resolution shall be at least 12
bits with a sampling rate of at least 1 MS/sec. (adjustable). The memory depth per channel
shall be 1 MB. The supplier has to build the system for reliable operation in high
electromagnetic noise- level environment prevailing in the laboratory particularly during the
8/9/2019 T3S - 31 - Specs_50 MVA_refurbishment
http://slidepdf.com/reader/full/t3s-31-specs50-mvarefurbishment 9/27
actual transient test conditions. The supervisory and monitoring signals for the equipment
in general and the test data in particular needs complete noise immunity. The supplier
therefore has to use proven and reliable technologies of digital communication utilizing
suitable network protocol like Modbus / Profibus. However for acquiring test data, an
additional arrangement for analog signal transmission to the control room shall also beprovided as an option.
3.1.5.3 The supplier will have to state the main principles of proposed plans to use for the control
and monitoring system. The PLCs shall be of of reputed makes (Siemens, Rockwell, etc)
with open system architecture. The detail of each control loop and automatic device may
not be furnished in the bid. However, the manufacturer will have to comply with the
general requirements of this section and ensure that his proposal enables finalization of
the detailed control and monitoring system arrangement. The scope of the work includes
redesigning of the scheme, supply and commissioning of the new integrated control
system. The supplier shall propose further extension of the laboratory if any required for
the purpose like control room and indicate the size and requirements of the same.
The Annexure-6 gives the essential schematic of the existing motor-generator set.
4.0 Manufacture, Erection and Commissioning
4.1 The manufacturer shall follow documented quality procedures (QAP) during the manufacture
of equipment/module/component, a copy of which shall be made available once the order
is issued. The components/modules to be sourced from other manufacturers shall be
clearly brought out in a separate bill of materials. These bought-out items shall be of
reputed makes (with warranty clause). All the sheet-steel panels, enclosures shall be of 7-
fold construction (for e.g. Rittal make).
4.2 The supplier has also to indicate the schedule of manufacture for enabling stage
inspection to be planned wherever deemed necessary by CPRI. The schedule for stage
inspection and final inspection programs have to be agreed together with dispatch
clearance criteria. A set of pre-manufacture documents shall be submitted for approval
containing among other things GA drawings, foundation details (with static weight), Bill of
materials, Schematics, interconnection diagrams, single-line diagrams. Periodic review of
the project - one weekly and other monthly- shall be held between CPRI & the supplier to
monitor the progress. The supplier shall indicate the exact dates. The equipment and all
8/9/2019 T3S - 31 - Specs_50 MVA_refurbishment
http://slidepdf.com/reader/full/t3s-31-specs50-mvarefurbishment 10/27
its components have to conform to the latest Indian/international standards. Tests shall
include all electrical, mechanical, pneumatic and hydraulic tests in the course of
manufacturing as well as the routine test after the completion of the manufacture. The final
tests on the completed equipment before dispatch shall be conducted as per the
procedures in the standards. The test report shall be submitted for approval beforedispatch.
4.3 Before the start of erection, the supplier has to submit for approval of CPRI, the program
of on-site test plan which shall include proving all the essential specification. The supplier
shall carry out tests at site in accordance with the on-site test plan. The supplier’s test
equipment shall be of satisfactory quality and condition with valid calibration.
4.4 At the time of erection, the supplier shall submit for approval fully detailed Installation,
Operating and Maintenance instructions. It will not be sufficient to incorporate the
manufacturer's standard brochures as part of the text unless they refer particularly to the
equipment supplied and are free from extraneous matter. Separate Operating & Maintenance
manuals are required for different modules. During the course of erection, the Purchaser
shall have full access for inspection of the progress of work and checking workmanship
and accuracy as may be required.
4.5 Initial energizing and subsequent “live” tests will be directed by CPRI and carried out
jointly by the CPRI and the supplier to ensure satisfactory performance to meet the ratings
of the generator system. The supplier shall remain responsible for his supply. The test
results can be used as a basis for maintenance test during the working life of the
equipment.
4.6 On completion of the erection work, prior to commissioning, all equipment shall be
inspected and tested to demonstrate that it is entirely suitable for commercial operation. A
general check of all the main and ancillary equipment shall be made and shall include a
check of the completeness, correctness and condition of earth connections, labeling,
clearances, painted surfaces, cables, wiring, pipe work, valves, and all other auxiliary and
ancillary items. A check shall be made that loose items which are to be handed over to the
Purchaser, e.g. tools, spares, are in order and are correctly stored or handed over.
4.7 The manufacturer will have to design the foundation complying with the requirements.
Necessary foundation details for the set wherever needed shall be presented. The design
8/9/2019 T3S - 31 - Specs_50 MVA_refurbishment
http://slidepdf.com/reader/full/t3s-31-specs50-mvarefurbishment 11/27
of the special foundations shall ensure prevent the surrounding equipments from any
disturbing vibration, allow the generator to run without high strains and eliminate any
build–up of oscillations due to successive vibration pulses. The behavior during fully
asymmetrical single- phase tests shall have to be specially studied. Spaces for cabling
and air coolers shall be provided. The manufacturer will have to supply all the necessarytechnical documents for laying the foundation block: calculation notes, drawings,
specification for building material, etc.
5.0 Training and Documentation
5.1 The supplier shall arrange for comprehensive and detailed training programs for CPRI
personnel - both class room and on-the job. The number of personnel would be decided by
CPRI. The training shall cover all the aspects of operation/maintenance and basic trouble-
shooting. A special training would also be required for implementation of drive system (PCB
cards), control, communication systems, PLC aspects (operation and programming) of the
complete control scheme that the supplier chooses to use. This could be for example, the
bus systems, communication protocols, and other digital communication aspects.
5.2 The supplier shall submit complete documentation which shall be comprehensive. It shall
be reader-friendly with illustrations in suitable form like, schematics, graphs, pictures,
photographs, circuit diagrams, schedule and bill of material, spare part list, trouble
shooting procedures, etc. The documentation shall be supplied in both hard copy and
reproducible soft copy. Four copies of hard copy shall be submitted, printed and elegantly
hard bound. Three soft copies – one in PDF format and another in AUTOCAD format shall
also submitted.
6.0 General requirements
6.1 The bidder shall have to propose and quote for necessary/essential spares and tools. Two
separate lists, in accordance with the following requirements would be made:
6.2 The first list will include the so-called normal wear parts which are recommended to be
procured for first five years normal operation. This could include but not limited to for
example: brushes for rotor slip- ring, bearing linings, pump impellers, pump shafts,
bearings, gears, main screw and driven screws for the main lubricating pumps, pressure
8/9/2019 T3S - 31 - Specs_50 MVA_refurbishment
http://slidepdf.com/reader/full/t3s-31-specs50-mvarefurbishment 12/27
reducers, filters, valves, pressure controllers, thermostats, probes, sensors, recorder
parts, protective relays etc.
6.3 The second list will include the spares which are not to be replaced in normal operation
but the failure of which will forbid tests to be carried out for an excessive duration takinginto account the delivery period. This could include but not limited to main electronic
devices such as: thyristors, complete electronic boards covering the main functions, PLC
modules etc.
6.4 The supplier shall propose all the necessary special tools needed for both routine and
major maintenance of the machine, its auxiliaries and ancillaries. The supplier shall
indicate the proposed maintenance schedule during the guarantee period and the life
period of the machine. The supplier shall also indicate the minimum life period of the
various equipments offered, when operated and maintained, in accordance with the
instructions of the manufacturers/ suppliers. The supplier shall offer to supply the spares
and tools for a period of at least 20 years.
6.5 The supplier also give the details of the changes he is making in the current set-up to
accommodate a new feature which may demand extra resources from CPRI like additional
/ larger space allocation, provision of higher electricity demands, etc.
6.6 The bidder shall give estimated time to complete the work of refurbishment. This is
important since the down-time of the machine affects the commercial interest of the
laboratory. Therefore it is expected that the bidder accurately estimates the time for which
the facility have to be shut down. This time would be factored in terms of loss of revenue
of the laboratory while calculating the total cost.
6.7 The bidder shall give list of his clients to whom he has supplied similar equipment with
contact details.
6.8 The bidder shall furnish the guaranteed technical particulars (GTP) as per the enclosed
format. The particulars shall include but not limited to the parameters specified in the
format. Simplified drawings of the main parts and layout of various equipment with their
details forming part of the “refurbishment package” may be given wherever necessary.
8/9/2019 T3S - 31 - Specs_50 MVA_refurbishment
http://slidepdf.com/reader/full/t3s-31-specs50-mvarefurbishment 13/27
6.9 Warranty: The supplier shall offer a comprehensive warranty against the entire system to
be supplied by him for a minimum of three (3) years.
6.10 The price bid shall be given as following:
A. Refurbishment with replacement and modifications as per Item 2.7.1 to 2.7.5
A1 Main Parts (with detailed list)
A2 Spares (with detailed list)
A3 Training
Alternatively
B. Refurbishment with new set-up (covering all the scopes of 2.7.1 to 2.7.5)
B1 Main Parts (with detailed list)
B2 Spares (with detailed list)
B3 Training
XXXXXX
Encl: 1. GTP form
2. Annexures: 1, 2 , 3, 4, 5 & 6
8/9/2019 T3S - 31 - Specs_50 MVA_refurbishment
http://slidepdf.com/reader/full/t3s-31-specs50-mvarefurbishment 14/27
Guaranteed Technical Particulars
The bidder is requested to give the information pertaining to but not limited to following particulars.
Sl.No.
Technical Particulars Requirement ReferenceClause
Complies(Yes/No)
Generator Coils
1 Stator coils
Rotor coils
72 no.s copper
6 no.s copper
3.1.1
2 Insulation class H for stator coils
F for rotor coils
3.1.1
3 Design and manufacture As per existing coil ;
(details in annexure 3;samples available)
3.1.1
Sl.No.
Technical Particulars Requirement ReferenceClause
Complies(Yes/No)
Fly wheel
1 Type MS Fabricated 3.1.2.1
2 Construction Cylindrical ---
3 Moment of inertia Suitable to be fitted tothe specified
generator to give50MVA for 1.0 secondat 0.25 power factor
lag
3.1.2.2
4 Mounting Pedestal ---
5 Lubrication To be specified by thebidder
---
6 Type of Coupling To be specified by thebidder
---
8/9/2019 T3S - 31 - Specs_50 MVA_refurbishment
http://slidepdf.com/reader/full/t3s-31-specs50-mvarefurbishment 15/27
Sl.
No.
Technical Particulars Requirement Reference
Clause
Complies
(Yes/No)Excitation System
1 Type Microprocessor basedStatic excitation
system
3.1.3.2
2 No-load & impulse excitationcurrent
Suitable for thesystem to give 50MVAoutput for 1.0 second.
To be specified by thebidder
3.1.3.3
3 Control system Closed loop feedback
to maintain theGenerator output
current constant withaccuracy better than
1%
3.1.3.3
4 Response time To be specified by thebidder
3.1.3.3
5 Number of pulse Preferably 12 pulse 3.1.3.4
6 Total harmonic distortion Less than 8% 3.1.3.4
8/9/2019 T3S - 31 - Specs_50 MVA_refurbishment
http://slidepdf.com/reader/full/t3s-31-specs50-mvarefurbishment 16/27
Sl.No.
Technical Particulars Requirement ReferenceClause
Complies(Yes/No)
Drive motor
1 Input voltage To be specified by thebidder
3.1.4.1
2 Rated output 750kW minimum 3.1.4.1
3 Type of motor variable speed 3.1.4.1
4 Insulation Minimum Class ‘F’ 3.1.4.1
5 Dimensions of motor To be specified by thebidder
---
6 Net weight To be specified by thebidder
---
7 Acceleration time Less than 1 minute ---
8 Output Torque To be specified by the
bidder along withspeed-torque curve
---
9 Losses at full load To be specified by thebidder
---
10 Type of cooling To be specified by thebidder
---
11 Source Transformer ratings (for motor)
To be specified by thebidder
---
12 Conforming to IS 4722:2001 & IEC60034 (relevant parts)
3.1.4.2
13 Quality assurance ISO 9001, ISO 14001 3.1.4.2
Drive for motor
1 Type Static 3.1.4.3
2 Total harmonic distortion Less than 8%;Compliance to IEEE
519 Harmonicanalysis
3.1.4.4
3 Input voltage To be specified by thebidder
---
4 Number of pulse To be specified by thebidder
3.1.4.3
5 Protection Over-voltage & surge,phase loss, overload,temperature etc.
---
6 Quality assurance ISO 9001, ISO 14001 3.1.4.2
8/9/2019 T3S - 31 - Specs_50 MVA_refurbishment
http://slidepdf.com/reader/full/t3s-31-specs50-mvarefurbishment 17/27
Sl.No.
Technical Particulars Requirement ReferenceClause
Complies(Yes/No)
Operation & control
1 Type PLC based 3.1.5.1
2 Communication MODBUS/PROFIBUS 3.1.5.3
3 Number of channels/control signals 24 (minimum) 3.1.5.2
4 Data acquisition system At least 12 bit
24 channel isolatedsingle ended ; 1 MS/s
3.1.5.2
5 Output of synchronous testprocessor ( sequence controller)
24 channels 6A 230VAC/DC
---
6 Noise immunity EMC & EMIcompatibility
3.1.5.2
7 Type of control PLC based viaComputer / self programmable
---
8/9/2019 T3S - 31 - Specs_50 MVA_refurbishment
http://slidepdf.com/reader/full/t3s-31-specs50-mvarefurbishment 18/27
Sl.No.
Technical Particulars Requirement
Short-circuit Generator (If bidder quotes for new Short-circuit Generator)1 Maximum output voltage 12kV
2 Output power 50MVA for 1.0 second
3 Stator coil insulation Class ‘H’
4 Rotor coil insulation Class ‘F’
5 Dimensions of Generator To be specified by the bidder
6 Moment of inertia To be specified by the bidder
7 Type of rotor construction To be specified by the bidder
8 Synchronous speed To be specified by the bidder
9 Sub-transient reactance / time constant Suitable to give minimum 50MVA
output
10 Transient reactance/time constant Suitable to give minimum 50MVAoutput at the end of 150mS
11 Number of windings per phase (for series parallel connection)
Two
12 Stator winding connections 3.46kV, 6.92kV, 6kV & 12kV
13 Frequency 50 & 60Hz operation
14 Excitation voltage & current To be specified by the bidder
15 Field time constant To be specified by the bidder (asminimum as possible)
17 Type of cooling To be specified by the bidder 18 Weight of the rotor To be specified by the bidder
19 Lubrication To be specified by the bidder
20 Conforming to IS 4722:2001 & IEC 60034 (relevantparts)
21 Quality assurance ISO 9001, ISO 14001
8/9/2019 T3S - 31 - Specs_50 MVA_refurbishment
http://slidepdf.com/reader/full/t3s-31-specs50-mvarefurbishment 19/27
Annexure-1
Technical details of existing 50MVA SC Generator
Three phase synchronous generator of enclosed self-ventilating design with horizontal shaft. On
the one end of the shaft rotor of the main exciter is mounted and the other end of the shaft is
coupled to he driving motor which is an induction motor. On the top of the generator a link board
for manual reconnection of the different voltages is mounted. The generator has the following data.
Make ASEA, Sweden
Output 50MVA calculated at the end of 0.2second short-
circuit and the recovering voltage of 12kV
Continuous output 5MVA, 12kV 241A
Standard BS 2613
Nominal voltage 12(star-series), 12/ √3(delta-series), 6(star-parallel) and
6/√3 kV (delta-parallel)
Frequency 50HzSynchronous speed 1000 rpm
Stator windings per phase Two
Nominal current 2410A in 12kV connection
Quantity of cooling air 360m3/min.
Moment of inertial 1550kgm2
Lubrication Self-lubrication
Runaway speed 1250 rpm
Stator insulation Class B
Rotor insulation Class A
Losses Approx. 2.5% of rated output
Total net weight 30 tons Net weigh of the stator 13.5 tons
Net weight of the rotor 10.9 tons
Time of retardation 34 minutes
Reduction of speed Speed reduction after a short circuit at nominal
charge and a duration of 0.2 sec. are;
at power factor less than 0.1 : 5%
at 0.12 pf : 6%
at 0.3 pf : 8%
Voltage at initiation of
short-circuit Not greater than 115% of the recovery voltage
Sub-transient reactance 1.7Ω in (star-series connection)
Transient reactance 2.22Ω
Synchronous reactance 14.3ΩExcitation voltage & current 550Vdc 1360A for 0.2 second
8/9/2019 T3S - 31 - Specs_50 MVA_refurbishment
http://slidepdf.com/reader/full/t3s-31-specs50-mvarefurbishment 20/27
N
Annexure-2
Page 1 of 2
Layout plan of 50MVA SC test laboratory
Note:
G - Short-circuit generator with exciter
B - M-G set machine bed
M - Driving motor
T1,T2 - Short-Circuit Transformers
Note: All dimensions are in foot
131’
G M
Machine Control Room
Control Panels
26’
23’
17’
20’
45’
57’
B
Test Cell-3 Test Cell-2 Test Cell-1
T2 T1
Control Room
Handling bay
8/9/2019 T3S - 31 - Specs_50 MVA_refurbishment
http://slidepdf.com/reader/full/t3s-31-specs50-mvarefurbishment 21/27
Annexure-2
Page 2 of 2
Single line diagram of the existing 50MVA SC Test facility
8/9/2019 T3S - 31 - Specs_50 MVA_refurbishment
http://slidepdf.com/reader/full/t3s-31-specs50-mvarefurbishment 22/27
8/9/2019 T3S - 31 - Specs_50 MVA_refurbishment
http://slidepdf.com/reader/full/t3s-31-specs50-mvarefurbishment 23/27
Annexure-3
Page 1 of 2
8/9/2019 T3S - 31 - Specs_50 MVA_refurbishment
http://slidepdf.com/reader/full/t3s-31-specs50-mvarefurbishment 24/27
Annexure-3
Page 2 of 2
8/9/2019 T3S - 31 - Specs_50 MVA_refurbishment
http://slidepdf.com/reader/full/t3s-31-specs50-mvarefurbishment 25/27
Annexure-4
Schematic of the existing excitation scheme for 50MVA SC Generator
8/9/2019 T3S - 31 - Specs_50 MVA_refurbishment
http://slidepdf.com/reader/full/t3s-31-specs50-mvarefurbishment 26/27
Annexure-5
Schematic diagram of Generator-Motor-Exciter set
8/9/2019 T3S - 31 - Specs_50 MVA_refurbishment
http://slidepdf.com/reader/full/t3s-31-specs50-mvarefurbishment 27/27
Annexure-6
Technical details of the existing driving motor
The driving motor is a 3Phase Slip Ring Induction motor of enclosed self –ventilating design
with horizontal shaft and flange for coupling to the generator. Following are its technical
particulars;
Continuous rated output 750kW
Speed 985 rpm
Synchronous speed 1000 rpm
Frequency 50Hz
Input voltage 3.3kV
Losses at full load 5kWRunaway speed 1250rpm
Efficiency at full load 94.3%
Net weight 3.7 tons
Acceleration / starting time 63 seconds
Type of starter Rotor resistance type (divided in to 3 steps)