JB/T 7074-1993 General technical requirements for gas turbine generators
Some standard content:
Mechanical Industry Standard of the People's Republic of China
General Technical Conditions for Gas Turbine Generators
This standard refers to the international standard IEC34-3 (1988) "Technical Requirements for Turbine-Type Synchronous Motors". 1 Subject Content and Scope of Application
JB/T 707493
This standard specifies the types and basic parameters, technical requirements, test methods, inspection rules, complete set supply scope, marking, packaging, transportation and storage of gas turbine generators.
This standard applies to 1~100MW air-cooled three-phase synchronous generators connected to gas turbines. All matters not specified in this standard shall comply with the relevant provisions of GB755 "Basic Technical Requirements for Rotating Electrical Machines". If there are special requirements for specific products, they can be jointly agreed upon by the user and the manufacturer on the basis of this standard. Cited Standards
GB755 Basic Technical Requirements for Rotating Electrical Machines
GB/T1029 Test Methods for Three-Phase Synchronous Motors Vibration Measurement Methods
GB 10068.1
Measurement method and limit of vibration of rotating electrical machine
GB10069.1
Measurement method and limit of noise of rotating electrical machine
GB10069.2Measurement method and limit of noise of rotating electrical machine GB191 Pictorial mark for packaging, storage and transportation
GB/T13384
General technical conditions for packaging of electromechanical products
3 Type and basic parameters
3.1 Type
3.1.1 Ventilation type
Noise engineering measurement method
Simple noise measurement method
Generally, a closed-cycle ventilation type is adopted, and the air is cooled by an air cooler. An open ventilation type can also be provided according to user needs.
3.1.2 Bearing type
Gas turbine generators use end cover bearings or seat bearings. 3.1.3 Excitation type
Generally, a brushless excitation system is used, and other excitation methods can also be used. 3.2 Rotation direction
The rotation direction of the gas turbine generator is clockwise when viewed from the gas turbine end to the generator. 3.3 Motor insulation
The stator and rotor insulation systems should use insulation materials of Class B or above with heat resistance. 3.4 Stator winding connection and phase sequence
The stator winding is generally connected in Y type, and the phase sequence of the stator winding according to the specified rotation direction should be marked as U, V, W. 3.5 Rated speed
Generator with frequency of 50Hz: 1500r/min or 3000r/min; Approved by the Ministry of Machinery Industry on October 8, 1993
Implemented on January 1, 1994
JB/T7074-93
Generator with frequency of 60Hz: 1800r/min or 3600r/min. 3.6 Specifications
For gas turbine generators, no specific power level is specified. Table 1 lists the typical power levels and the corresponding voltage levels, power factors and efficiency values. The parameters of gas turbine generators of other capacity levels shall be determined in accordance with Table 1. Table 1
Active power
Apparent power
Stator voltage level
0. 4,3. 15,6. 3
0.4,3.15,6.3,10.5
3.15,6.3,10.5
10.5,13.8
Note: The efficiency values of 50.60 and 100MW gas turbine generators are to be determined. 4
Technical requirements
4.1 Operating conditions
4.1.1 Altitude not exceeding 1km
4.1.2 Primary cooling medium temperature
Power factor
4.1.2.1 The primary cooling medium overflow of a gas turbine generator using closed cycle cooling refers to the air temperature entering the motor from the cooler. The manufacturer shall determine the temperature range of the primary cooling medium according to the temperature range of the secondary (final) cooling medium (ambient temperature air or water) given by the user.
For gas turbine generators using an open ventilation system, the temperature of the primary cooling medium usually refers to the ambient air temperature on site, and its temperature range is determined by the user, usually -5 to +40°C. 4.1.3 Number of starts
The number of times the gas turbine generator is started with load shall not exceed 500 times per year. 4.1.4 Loading speed
The gas turbine generator can apply load quickly, and its loading speed is only limited by the loading capacity of the gas turbine. Voltage and frequency range
The gas turbine generator should be able to continuously output rated power when operating at rated power factor, voltage variation range of ±5% and frequency variation range of ±2% (as shown in the shaded area in Figure 1). The temperature rise limit specified in Table 2 is only applicable to rated operating conditions. When the operating point of the generator deviates from the rated voltage and frequency, the temperature rise or temperature of the motor will gradually exceed the specified value. For motors that continuously run at the shaded boundary, the temperature rise increases by about 10K. When the gas turbine generator outputs rated power at the rated power factor, the voltage variation range is ±5% and the frequency variation range is -5% to -2% and +2% to +3% (as shown in the area between the virtual and real boundary lines in Figure 1), the temperature rise will further increase. Therefore, in order to prevent the life of the motor from being shortened due to the influence of temperature or temperature difference, when the motor runs outside the shaded area, the duration and number of occurrences should be limited, and the capacity should be reduced as soon as possible or other measures should be taken. JB/T 707493
For gas turbine generators with rated voltage of 6.3kV and below and rated power of less than 10MW, they should be able to operate continuously when the voltage is increased to 110% of the rated value, but at this time the stator current should be limited to the excitation current not exceeding its rated value. U(%)
102,103
Voltage and rated power operating range
4.2 Rated power and capacity
4.2.1 Rated power
The rated power of a gas turbine generator refers to the effective continuous apparent power at the generator output terminal when the rated frequency, rated voltage and rated power factor and the primary cooling medium temperature at the power plant site is 40℃ and the temperature rise or temperature of the motor does not exceed the specified value in Article 4.3.1. Unless otherwise agreed, the parameters of the gas turbine generator should be determined under the rated state. Note: Since the rated value of the gas turbine is determined at an air inlet temperature of 15℃ and the rated value of the gas turbine generator is determined at an air inlet temperature of 40℃, if the gas turbine and the generator have the same capacity, their rated power will be different. 4.2.2 Capacity
The capacity of a gas turbine generator refers to the maximum load acceptable under the specified operating conditions, expressed in apparent power. ：4.2.2.1 Basic capacity
The basic capacity of a gas turbine generator refers to the continuous output range expressed in apparent power at the motor outlet when the motor temperature rise and temperature do not exceed the specified values in Article 4.3.2, according to the final cooling medium temperature range specified for on-site operation of the power plant at rated frequency, rated voltage and rated power factor. 4.2.2.2 Peak capacity
The peak capacity of a gas turbine generator refers to the continuous output range expressed in apparent power at the motor outlet when the motor temperature rise and temperature do not exceed the specified values in Article 4.3.3, according to the final cooling medium temperature range specified for on-site operation of the power plant at rated frequency, rated voltage and rated power factor. 4.2-2.3 Capacity curve and capacity matching
The manufacturer shall provide the capacity curve when the final cooling medium temperature is within the specified range at the power plant site. The typical output curve of the gas turbine generator is shown in Appendix A (Supplement).
The matching relationship between the generator capacity and the gas turbine capacity shall be determined by negotiation between the manufacturer and the user. The value obtained by dividing the active power of the generator by the generator efficiency shall be equal to or exceed the capacity of the gas turbine when the inlet air temperature at the power plant site is within the specified range.
4.3 Temperature and temperature rise limit
4.3.1 Temperature and temperature rise limit at rated power 4.3.1.1 The temperature rise of each part of the indirectly cooled gas turbine generator at rated power shall not exceed the limit values in Table 2. 508
Generator components
Stator winding
Rotor winding
Stator core
JB/T7074-93
Temperature rise limit when the primary cooling medium is 40C B satin
Measurement method
Buried thermometer method
Resistance method
Buried thermometer method
For gas turbine generators with direct cooling of rotor windings, the temperature of the rotor winding measured by the resistance method shall not exceed the limit values in Table 3. Table 3
Cooling air on the entire length of the rotor
Number of radial outlet channels
8 and above
4.3.2 Temperature and temperature rise limit at basic capacity Class B
4.3.2.1 For indirect-cooled gas turbine generators, the temperature rise during field operation shall be corrected as follows according to the provisions of Table 2; a.
When the primary cooling medium temperature is 10-60°C, add: T=40-t
Where: T—.
Increase in temperature rise, K;
The value of the primary cooling medium temperature, C.
When the primary cooling medium temperature is lower than 10°C but not lower than -20°C, it is differentiated according to the effective length of the motor: when the core length is less than 2.5m, add:
Where: T—.
Increase in temperature rise, K;
The value of the primary cooling medium temperature, C.
When the core length is greater than or equal to 2.5m, add 30K, (10-t).
When the primary cooling medium temperature is higher than 60°C or lower than -20°C, it shall be agreed upon separately by the manufacturer and the user. e.
（2）
4.3.2.2 For gas turbine generators with direct rotor winding cooling, the rotor winding temperature during field operation shall be corrected as follows according to the provisions of Table 3:
When the primary cooling medium temperature is 1060℃, no correction:When the primary cooling medium temperature is lower than 10℃, but not lower than -20℃, differentiate according to the effective length of the motor:When the core length is less than 2.5m, reduce:
(10-1）
Where: T---temperature rise reduction, K;
t,--the value of the primary cooling medium temperature, C.When the core length is greater than or equal to 2.5m, reduce:T=10-
（3）
Where:T
temperature rise reduction, K;
JB/T7074--93
the value of the primary cooling medium temperature, C.
When the primary cooling medium overflow is higher than 60°C or lower than -20°C, the manufacturer and the user shall agree separately. c.
4.3.3 Temperature and temperature rise limit at peak capacity The temperature and temperature rise limit at peak capacity of gas turbine generators are 15K higher than the provisions of Article 4.3.2. Note: The accelerated insulation aging rate when operating at peak capacity will shorten the life of the motor, because the insulation aging rate at this time is 3 to 6 times that of the basic capacity. 4.3.4 Bearing oil outlet temperature and bearing shell temperature limit Under the specified operating conditions and rated power operation, the bearing oil outlet temperature should not exceed 65°C, and the bearing shell temperature should not exceed 80°C.
4.4 Thermometer position and number
4.4.1 The number of embedded resistance thermometers for stator windings and stator cores is: 6 for those below 10MVA, and 6 for stator windings and stator cores for those above 10MVA.
4.4.2 The air inlet and outlet of the gas turbine generator should be equipped with a thermometer. 4.4.3 The air inlet and outlet of the cooler should be equipped with a thermometer. 4.4.4 The bearings at both ends should be equipped with a thermometer. 4.5 Short-circuit ratio and reactance
4.5.1 The short-circuit ratio of the gas turbine generator shall not be less than 0.45. 4.5.2 The ultra-transient reactance (saturation value) of the gas turbine generator shall not be less than 0.1. 4.6 Vibration value
When the gas turbine generator is running alone at rated speed, the allowable vibration value (double amplitude) in the vertical and horizontal directions on the bearing seat shall not exceed 0.03mm for a two-pole motor and not exceed 0.05mm for a four-pole motor. 4.7 Noise value
The A-weighted sound pressure level noise value of the gas turbine generator shall not exceed 92dB(A). 4.8 Critical speed
The critical speed of the gas turbine generator shall be outside the frequency range and the corresponding speed range specified in Article 4.1.5, and have sufficient margin. 4.9 Overspeed
The rotor shall be subjected to an overspeed test at a speed of 120% of the rated speed for 2 minutes. 4.10 Permissible deviation of three-phase DC resistance of stator winding When the stator winding is in a cold state, the difference in DC resistance between any two phases shall not exceed 2% of its minimum value after excluding the error caused by different lead lengths.
4.11 Insulation resistance
4.11.1 When the stator winding is close to the working temperature, the insulation resistance to ground and between phases measured with a 2.5kV megohmmeter shall not be less than the value obtained by formula (5):
1000+P/100
Wherein; R-insulation resistance value, MQ;
U-rated voltage of the motor winding, V;
P·rated power of the motor, kVA.
When the temperature during measurement is lower than the working temperature, the insulation resistance value shall be converted. 4.11.2 The insulation resistance of the rotor winding shall not be less than 1MQ when measured with a 500V megohmmeter in a cold state (20°C). 4.11.3 The insulation resistance of the stator embedded thermometer shall not be less than 1MQ when measured with a 250V megohmmeter in a cold state. 4.11.4 The insulation resistance of the heater shall not be less than 1Mα when measured with a 500V megohmmeter in a cold state. (5)
4.11.5 The bearing at the exciter end shall be insulated from the base plate (bearing) and the oil pipe. The insulation resistance shall not be less than 510
and shall not continue to read
1Mo.
4.12 Shaft current
JB/T7074-93
Appropriate measures shall be taken to prevent harmful shaft current current, and ensure that the rotor is well grounded. 4.13 Withstand voltage test
4.13.1 Gas turbine generators with a rated power of 10MW and above and a rated voltage of 6kV and above shall be subjected to a 3.5 times rated voltage test in the manufacturer and a 3 times rated voltage DC withstand voltage test at the installation site, both lasting 1 minute. 4.13.2 The stator winding and rotor winding after assembly shall be able to withstand the AC power frequency withstand voltage test as shown below, lasting 1 minute. a. Stator winding: 2 times rated voltage plus 1kV; b. Rotor winding: 10 times rated excitation voltage, but the minimum is 1.5kV. 4.14 Output diagram
The manufacturer shall provide an output diagram indicating the operating limits of the generator. See Appendix B (supplement) for typical output diagrams. The gas turbine generator shall operate at Within the boundaries specified in the output diagram, operation beyond the boundaries will shorten the life of the motor. 4.15 Irregularity of voltage waveform
4.15.1 Sinusoidal distortion rate of voltage waveform
At no-load rated voltage, the sinusoidal distortion rate of its line voltage waveform should not exceed 5%. 4.15.2 Telephone harmonic factor THF
When the gas turbine generator is at no-load rated voltage and rated speed, the telephone harmonic factor of its line voltage should not exceed 3% for 5MW and below, and not exceed 1.5% for above 5MW.
4.16 Requirements for abnormal normal operation
4.16.1 Unbalanced current
When the three-phase load of the gas turbine generator is asymmetrical, the current of each phase shall not exceed the rated current for 1s, and the negative sequence current component 1. When the ratio of 12/I to the rated current meets the requirements of Table 4, it should be able to operate continuously. In the event of an asymmetric fault, the product of the maximum (1z/1%) and duration of the fault operation should meet the requirements of Table 4.
Rotor structure type
Rotor cooling method
Indirect cooling
Direct cooling
4.16.2 Maximum continuous operation of stator winding short-time overcurrent and excitation winding short-time overvoltage
Maximum (Iz/1%) of fault operation
4.16.2.1 The stator winding of the gas turbine generator should be able to withstand a short-time overcurrent of 1.5 times the rated current for 30s without damage. Under the same additional heating degree of the motor, the motor should also be able to allow the overcurrent multiple and overcurrent time combined according to the following formula. (r-1)t=37.5s
Where: I-stator overcurrent standard value;
stator overcurrent duration, $.
The applicable range of time t in the above formula is 10～60s. (6)
Note: When operating under the above overcurrent conditions, the stator temperature will exceed the value at rated load. The motor structure design should be based on the overcurrent not exceeding 2 times per year.
4.16.2.2 The excitation winding should have the short-time overvoltage capability specified in Table 5. 511
Excitation voltage
JB/T7074—93
Note: When operating under the above conditions, the temperature of the excitation winding will generally exceed the value at rated load. Therefore, the motor structure design should be able to withstand the above operating conditions, but not more than 2 times per year.
4.16.3 Sudden short circuit
If the phase current during short circuit is limited to not more than the maximum phase current value obtained by three-phase short circuit, the gas turbine generator is rated load and 1.When running at 0.5 times the rated voltage, it should be able to withstand any form of sudden short circuit at the outlet without causing damage that leads to shutdown. The full voltage short circuit test is generally not carried out in the manufacturer. If the manufacturer and the user agree to carry out a sudden short circuit test on a new motor, the test should be carried out according to the following requirements after the full voltage withstand test: For generators directly connected to the power grid, a three-phase sudden short circuit test should be carried out at the outlet under no-load rated voltage; a.
b. For generators connected to the power grid through transformers or reactors, the sudden short circuit test can be carried out at the generator outlet with reduced voltage with the consent of the manufacturer and the user. At this time, the same stator current should be generated when a three-phase short circuit occurs on the high-voltage side of the transformer or reactor system during operation, and the motor should run at no load during the test.
After the sudden short circuit test, if the motor does not need to be repaired or only needs to slightly repair the stator winding and can withstand the withstand voltage test of 80% of the value specified in Article 4.13.2, the sudden short circuit test is considered qualified. Minor repairs mean that the end winding support structure can be repaired and some insulation can be added, but the windings cannot be replaced.
Note: If the generator is running and abnormally large current and torque are caused by a short circuit at the near end or a fault clearance overlap at the far end, as well as missynchronization, then the generator, especially the stator winding, must be thoroughly checked for caution. Before the motor is put back into operation, all loose parts or fillers should be eliminated to prevent further damage due to vibration in the future. The coupling bolts, couplings and shafts should also be checked for possible deformation. 4.17 Short-time voltage increase test
The short-time voltage increase test is carried out under no-load conditions, the test voltage is 1.3 times the rated voltage, and the test time is 1 minute. 4.18, Air Cooler
4.18.1 The air cooler for the gas turbine generator shall be able to ensure that the temperature of the cooled air does not exceed 40℃ when the inlet water temperature does not exceed 33℃
4.18.2 The air cooler shall be designed for a working water pressure of not less than 0.2MPa; the test water pressure shall not be less than 2 times the working water pressure for 30min.
If the cooler water pressure is controlled by a valve or a pressure reducing device of the water source, and the water source pressure is higher than the working pressure of the cooler, the cooler shall be designed for the higher pressure. Unless otherwise agreed, the test water pressure shall be 1.5 times the higher pressure, and the higher pressure value shall be specified by the user. 4.18.3 The design of the air cooler shall ensure that when one of the coolers stops for some reason, it can at least bear the continuous operation of the generator with two-thirds of the rated load, and the motor does not exceed the allowable temperature. In this case, the primary cooling air temperature can be higher than the design value. 4.18.4 When the air cooler is placed on the top of the gas turbine generator, a water leakage detection device shall be provided. 4.19 Heater
Gas turbine generators should be equipped with corresponding heaters. 4.20 Fire-fighting measures
Gas turbine generators should take corresponding fire-fighting measures. 4.21 Magnetic Auxiliary System - and Exciter
The excitation system should ensure the excitation required by the gas turbine generator under the various working modes specified in this standard. The technical requirements for the excitation system and exciter are specified in their respective standards. 512
Scope of complete set supply and spare parts
The scope of complete set supply of gas turbine generators is as follows; a.
Generator body:
Exciter and excitation system device;
JB/T7074-93
Air cooler (only for closed circulation system); heater;
Special tools required for disassembly and assembly (only one set is provided for the first unit of the same type of machine in each power station when it is shipped). Spare parts
Stator coil: 6 coils for the upper layer and 2 coils for the lower layer for the bar coil; 3 coils for the ring coil; one set of bearing bushings.
Note: The spare parts of the excitation system and the exciter are specified in their respective standards. 6 Test methods
6.1 The vibration test shall be carried out in accordance with the provisions of GB10068.1. 6.2 The noise test shall be carried out in accordance with the provisions of GB10069.1 or GB10069.2. 6.3 Other tests shall be carried out in accordance with the relevant provisions of the national standard "Test Methods for Three-Phase Synchronous Motors". 7 Inspection rules
Inspection is divided into "exit inspection", type inspection and handover inspection after installation. 7.1 Delivery Inspection
Each gas turbine generator shall be subject to a delivery inspection before leaving the factory, and the items are as follows: a..
Measurement of insulation resistance of windings, resistance thermometers, heaters, bearings to ground and insulation resistance between winding phases; measurement of DC resistance of windings and resistance thermometers in actual cold state: rotor dynamic balancing and overspeed test;
Withstand voltage test:
loss heating test of stator core;
DC withstand voltage test of stator winding;
Measurement of AC impedance of rotor winding at different speeds (this test may not be performed when brushless excitation is used). Type inspection
The type inspection items of gas turbine generator are as follows: a.
All factory inspection items;
Determination of no-load characteristics:
Determination of steady-state short-circuit characteristics;
Temperature rise test (can be carried out at the installation site); Efficiency determination:
Short-time overcurrent test;
Sudden short-circuit mechanical strength test (see Article 4.16.3) Determination of rated excitation current and voltage regulation rate (can be carried out at the installation site); Determination of voltage waveform sinusoidal distortion rate and telephone harmonic factor; Determination of winding reactance and time constant;
Short-time increased voltage test;
Noise determination;
JB/T 7074---93
General mechanical inspection when there is no excitation, and determination of bearing oil temperature and vibration. 7.3 Handover inspection after installation
After the gas turbine generator is installed, the user, manufacturer and installation unit shall conduct a handover inspection. The specific items are as follows: a.
Measurement of insulation resistance of winding, resistance thermometer, heater, bearing to ground and insulation resistance between winding phases; measurement of DC resistance of winding and resistance thermometer in actual cold state; measurement of no-load characteristics and steady-state short-circuit characteristics; temperature rise test;
voltage withstand test, the test voltage is 80% of the value specified in Article 4.13.2; short-term voltage rise test;
test of the generator cooling system;
measurement of the voltage between the two ends of the shaft and the shaft to ground potential; mechanical inspection, measurement of bearing oil temperature and bearing vibration, etc.; stator winding DC withstand voltage test;
measurement of rotor winding AC impedance at different speeds (this test can be omitted when using brushless excitation). 7.4 Product certificate
The manufacturer shall make a factory inspection conclusion when the generator leaves the factory and fill it in the product certificate. The product certificate shall include all inspection records of factory inspection items and the water pressure inspection record of the cooler. 8
Marking, packaging, transportation and storage
8.1 Marking
8.1.1 Product nameplate
8. 1. 1. 1
8. 1. 1. 2
The nameplate of the gas turbine generator should include the following items: motor name;
manufacturer name;
product standard number;
motor model:
manufacturer production number;
production year and month;
wiring method;
rated frequency, Hz;
rated power, MVA or MW;
peak capacity, MVA or MW;
rated stator voltage, kV;
rated stator current, A;
rated power factor cos;
rated excitation current, A;
rated speed, r/min;
insulation grade;
temperature rise or temperature limit, K or ℃.
The nameplate of the air cooler shall include the following information: product name;
Manufacturer name;
Product standard number;
Cooler model:
Production number;
Production year and month;
Rated power, kW
Rated temperature of cooling water, C;
Water pressure drop, Pa;
Water consumption, m\/h;
Maximum working pressure, MPa;
Air volume, m2/s;
Air pressure drop, Pa.
8.2.1 Packaging requirements
JB/T7074—93
The gas turbine generator shall be packed according to the requirements of GB/T13384 when leaving the factory. If it is packed as a whole, measures must be taken to prevent axial movement. If the size exceeds the limit during transportation and needs to be disassembled for transportation, measures must be taken to prevent rainwater and other dirt from entering the motor. 8.2.2 Packaging Marks
The packaging marks of gas turbine generators shall comply with the provisions of GB191. 82.3
Random Documents and Drawings
The following random factory documents and drawings (in duplicate) should be included in the packaging. a.
Product certificate;
Installation, use and maintenance instructions;wwW.bzxz.Net
Packing list;
List of complete supply items;
Installation drawing:
General assembly drawing;
Stator assembly drawing:
Stator winding wiring diagram;
Stator coil diagram;
Layout of temperature measuring device;
Layout of stator heater;
Heater wiring diagram;
Rotor assembly drawing;
Rotor coil assembly drawing;
Bearing processing drawing;
Bearing assembly drawing:
Bearing insulation parts drawing;
Air cooler assembly drawing;
Disassembly and assembly tool drawing;
Oil circuit diagram;
Characteristic curve;
Electrical data.
During transportation, the generator should be kept dry and clean to prevent water, dust, oil, acid, alkali and other harmful substances from entering the motor. 8.4
JB/T7074--93
Gas turbine generators should be stored in dry and clean warehouses to prevent water, dust, oil, acid, alkali and other harmful substances from entering the motor. The exposed parts of the product should be coated with a rust-proof protective layer. If it is to be stored for a long time, it should be unpacked and inspected regularly, and the protective layer can be re-coated if necessary. 8.5 Warranty period
If the user uses and stores it correctly according to the provisions of this standard and the installation and maintenance instructions, the manufacturer should ensure that the gas turbine generator can operate well within the first year of use (but not more than two years from the date of shipment from the manufacturer). Within this specified period, if the generator is damaged or cannot work normally due to poor manufacturing quality, the manufacturer should repair (or replace) parts (or motors) for the user free of charge.
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