GB 50150-2006 Standard for Hand-over Test of Electric Equipment

UDC NATIONAL STANDARD OF THE PEOPLE'S REPUBLIC OF CHINA +~AR*$UE3E3%$3% Standard for Hand-over Test of Electric Equipment Electric Equipment Installation Engineering Issucd on June 20,2006 I m p l e n ~ e ~ ~on ~ eNovember tl , 2006 Jointly issued by the Ministry of Construction of the People's Republic of China and the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China The Ministry of Construction of the People's Republic of China No 438 Announcement of publishing the national standard "Standard for Hand-over Test of Electric Equipment Electric Equipment Installation Engineering" by the Ministry of ~onstruction "Standard for Hand-over Test of Electric Equipment Electric Equipment Installation Engineering" has been approved as a national standard with a serial number of GB 50150-2006, and implemented since November 1, 2006 Therein, articles (items) 3.0.1 (I, 4, and18),4.0,1(1,8and9),6.0.1(1),7.0.1(2,3,4and8),8.0.1(2),9.0.1(1,7and8),12.0.1 (2 and3), 13.0.1 (2, 12and 13), 14.0.1 (1,2,3 and4), 18.0.1 (1 and5),21.0.1 (I), 25.0.1 (1 and 3) and 26.0.1 (2) are compulsory provisions and must be enforced strictly "Standard for Hand-over Test of Electric Equipment Electric Equipment Installation Engineering" GB 50 150-9 shall be abolished simultaneously Authorized by Standard Rating Institute of Ministry of Construction, this code is published and distributed by China Planning Press The Ministry of Construction of the People's Republic of China June 20,2006 Foreword According to the requirements of Document Jiao Biao [2003] No.102 issued by the Ministry of Construction (M0C) "Notice on Printing the Development and Revision Plan of National Engifleering Construction Standards in 2002-2003", this standard is got by the revision edition of "Standard for Hand-over Test of Electric Equipment Electric Equipment Installation Engineering" GB 50150-1991 by the Electric Power Construction Research Institute of SGCC, Beijing and other organizations concerned The standard comprises 27 chapters and appendices with the main contents are: general provision; terms; synchronous generator and rotary condenser; direct current dynamo; intermediate frequency generator; alternating current motor; power transformer; reactor and arc-suppression coil; instrument transformer; oil circuit breaker; blowing air and magnetic blast breaker; vacuum circuit breaker; sulfur hexafluoride circuit breaker; sulfur hexafluoride gas insulated switchgear; isolating switch, load switch and high voltage fuse; bushing; suspension insulator and pillar insulator; power cable lines; capacitor; insulating oil and SF6 gas; arrester; electrostatic precipitator; secondary circuit; 1KV and less voltage power distribution equipment and feed line; overhead power line above 1KV; grounding connection; low-voltage electrical appliances Comparing with the original standard, this standard adds content as below: Terms; Implementing principles on standard for hand-over test of the imported equipment; , Natural-vibration frequency test and modal analysis on winding end of the generator stator; Note: "Measurement and Evaluation of the Dynamic Characteristic on Stator End Windings of the Large Turbo-generator-natural-vibration frequency test and modal analysis on winding end" D m 735-2000 The pilot project of Gas-insulated transformer, and the inspection and pilot project of the on-load transformer switching regulator device; Some pilot project and touchstone of the instrument transformer, breaker and electrostatic precipitator; Alternating current (hereinafter referred to as AC) withstand voltage test and crossing interconnected system test of power cable lines; Specification for the pilot project and grounding impedance value of the grounding connection An increase of four appendices: partial discharge test method of the transfortner; Excitation curve measurement of protected level of the current transformer; test method and requirementof power cable cross interconnected system; special pilot projects The provisions printed in bold type are compulsory provisions and must be enforced strictly The Ministry of Construction is in charge of the administration of this standard and the explanation of the compulsory provisions Electric Power Construction Research Institute of SGCC, Beijing is responsible for the explanation of specific technical contents All relevant organizations are kindly requested to sum up and accumulate your experiences in actual practices during the process of implementing this standard The relevant opinions and advice, whenever necessary, can be posted or passed on to Electric Power Consbuction Research Institute of SGCC, Beijing (address: N0.31, Nanbinhe Road, Xuanwu District, Beijing, China, Te1ephone:OlO-63424285) Chief Development Organization, Participating Development Organizations and Chief Drafting Staffs of this standard: Chief De~elopmentOrganization: Electric Power Construction Research Institute of SGCC, Beijing Participating Development Organizations: Anhui Electric Power Research Institute No Engineering Company of Northeast Power Administration Bureau China Electric Power Research Institute Wuhan High Voltage Research Institute North China Electric Power Research Institute Liaoning Electric Power Research Institute Guangdong Power Test & Research Institute Guangdong Power Transmission Comapny Power Transmission & Transformation Corporation Tianjin Electric Power Construction Company Shandong Electric Power Construction No Company Guangxi Transmission & Substation Construction Company Chief Drafting Staffs: Guo Shouxian, Sun Guanfu, Chen F a y , Yao Senjing, Bai Yamin, Yang Rongkai, Wang Xuan, Han Honggang, Xu Bin, Zhang Bin, Wang Xiaoqi, Ge Zhanyu, Liu Zhiliang, Yin Zhimin and Zhang Cheng Contents General provisions .; Terms Synchronous generator and rotary condenser Direct current dynamo 11 Intermediate frequency generators 13 Alternating current motor (AC motor) 14 Power transformers .16 Reactor and arc-suppression coil 23 Instrument transformers 25 10 Oil circuit breakers 30 11 Air and magnetic blast breaker .35 12 Vacuum circuit breakers 37 13 Sulphur hexafluorlde clrcuit breakers .38 14 Sulfur hexafluoride gas insulated switchgear 40 15 Isolating switch, load switch, and high voltage fuse 42 16 Bushing 43 17 Suspension insulator and pillar insulator 45 18 Power cable line 46 19 Capacitors 49 20 Insulating oil and SF6 gas 51 53 21 Arresters 22 Electrostatic precipitators 55 23 Secondary circults 57 24 1KV and less voltage power distribution equipment and feeder line 58 25 Overhead power line above 1kV 59 26 Grounding connection 60 27 Low-voltage electrical apparatus 62 Appendix A Voltage Standard for the Power Frequency Withstand Voltage Test of the Insulation of 63 High-voltage Electrical Appliance Appendix B the Reduction Coefficient of Ohmic Value Recalculation for the Winding Insulation 64 of Electric Machine Stator-to Working Temperature 65 Appendix C Test Method for Partial Discharge of Transformer Appendix D Reference Value for the DC Leakage Current of Oil-immersed Power Transformer 67 Winding Appendix E Measuring Method for the Current Transformer Excitation Curve of Protection Level 68 Appendix F Test Method and Requirements of the Transposition and Interconnection System of 72 Power Supply Cable 74 Appendix G Specific Test Project Explanation of Wording in This Standard 75 General provisions 1.0.1 This standard is formulated with a view to meet the requirement of hand-over test of the electric equipment electric equipment installation engineering and promotes popularization and applicatior of new technique for the hand-over test of electric equipment 1.0.2 This standard is applicable to hand-over test of 500kV and less voltage newly installed electric equipment which is eligible according to relevant works test standard of the nation This standard is not applicable to electric equipments installed under the colliery well or other site with explosive risk 1.0.3 Hand-over test of mechanical parts of the relay protection, automatism, telemechanism, communication, measurement, rectifying device and electric equipment shall be in accordance with the relevant provisions of standards or codes respectively 1.0.4 Electric equipment shall make AC withstand voltage test according to this standard, but if this standard not specifies requirement for electric equipment with voltage of 1lOkV and higher, it may not make AC withstand voltage test Making AC withstand voltage test, time shall be increased to duration time after standard voltage of the test, if no special requirement is made, it shall be lmin When the withstand test voltage value is calculated as multiple of the nominal voltage, dynamo and electromotor shall be calculated according to nominal voltage in the nameplate, and the cable may be calculated according to method specified in Chapter 18 of this standard AC withstand test voltage of off-standard voltage electric equipment may be calculate$ according to adjacent voltage proportions with interpolation method when no special requirement is made When making insulation test, it should make single test by separating the equipments link together in addition to the complete set of equipment assembled by the builder's Equipment with same touchstone may be tested together In order to convenient for field test work, same voltage but different touchstone electric equipments with works test records may be tested together when single test is difficult Touchstone shall adopt the minimum standard among all the connected equipments Insulation test for oil-immersed type transformer and reactor shall be made suffusing with corrected oil After standing for a certain period of time, it may be carried out after the elimination of air bubbles Standing time complies with the builder's requirement, when builder's hasn't any requirement, electric equipment with 500kV voltage shall be standing for more than 72h; 220-330kV for more than 48h; and llOkv and lower for more than 24h 1.0.5 When only individual item fells short of the requirement of this standard during the measuring and testing process on electric insulation, it shall make a comprehensive judgement on the test records, and the eligible one may be put into operation 1.0.6 When rated voltage and rated operational voltage in-service use are different, it shall determine the testing voltage according to the following requirements: It shall be made according to touchstone for rated voltage of the equipment when reinforcing insulation with electric equipment with higher rated voltage; It may make test according to touchstone for rated operational voltage of equipment in-service use when adopting electric equipment with higher voltage that meets the requirements of product commonality and mechanical strength; It may make test according to touchstone for rated operational voltage of equipment in-service use in the installation site when adopting electric equipment with higher voltage; 1.0.7 Making the temperature and humidity tests, it shall measure simultaneously the temperature and humidify around the tested objects Insulation test shall be made in the following conditions: in a fine day; the temperature around the tested object and equipment should not be lower than 5'C; relative humidity should not be higher than 80% Test data not satisfying with the above-mentioned temperature and humidity conditions shall be made with comprehensive analysis to determine whether electric equipment can be put into operation Test should pay attention to the impact of environmental temperature; for oil-immersed type transformer, reactor and arc-suppression coil, it shall use the upper-oil temperature of the tested object as the test temperature Normal temperature scope specified in this standard is 10'C-40°C 1.0.8 Insulation measurement listed in this standard shall be with insulation value of 60s; absorptance measurement shall be ratio between insulation value of 60s and 15s; polarization index shall be ratio between insulation value of lOmin and lmin 1.0.9 When making insulation test with the multi-winding equipment, non-tested winding shall be short-circuit grounding 1.0.10 Adopt voltage in the megger when measuring the insulation resistance; if this standard doesn't male any special requirement, it shall comply with the following requirements: Electric equipment or circuit lower than lOOV adopts 250V 50MQ and above megger; Electric equipment or circuit within 100V-500V adopts 500V 100MQ and above megger; Electric equipment or circuit within 500V-3000V adopts IOOOV 2000MQ and above megger; Electric equipment or circuit within 3000V-10000V adopts 2500V 10000ML2 and above megger; Electric equipment or circuit above lOOOOV adopts 2500V or 5000V 10000MQ and above megger When it is used for mensuration of polarization index, megger short-circuit current shall not be lower than 2mA 1.0.11 The high-pressure test method of this standards shall comply with requirement of current national standard "High Voltage Sest Techniques Part I: General Test Requirements" GBIT, "High Voltage Test Techniques Part 2: Measuring Systems" GBIT 16927.2, "Guide for Insulatio~iTest" DLIT 474.1-5 and relevant standard for requirement of equipment 1.0.12 Hand-over test of imported equipment shall comply with standard specified according to the contract But it shall pay attention to touchstone for the same pilot project when signlng the equipment contract and it shall not be lower than those specified in this standard 1.0.13 Tests with technical difficulty and specific requirement shall be made with the pilot project by the organizations with corresponding qualifications and test capacity, and these tests are classified as a special pilot projects Special pilot projects see Appendix G Terms 2.0.1 Power transformer Static equipment with two or more windings: in order to transfer power, it transfers alternating voltage and electric current in one system to voltage and currents in another system thlough electromagnetic induction under the same frequency under the same frequency Generally, these current and voltage values are different 2.0.2 Oil-immersed type transformer Transformer with iron core and winding immersed in the oil 2.0.3 Dry-type transformer Transformer with iron core and winding not immersed in the insulating liquid 2.0.4 Neutral terminal The three-phase transformer or three-phase group composed of single-phase transformer refer to common point (neutral point) terminal of Y-junction or meander configuration coupling; for the single-phase transformer, it refers to terminal connecting the network neutral point 2.0.5 Winding It composes a group of conductor turn of the electric circuit corresponding to a voltage labeled by the transformer 2.0.6 Tapping Among the transformers with tapping windings, each tapping connection of the winding> denotes its tapping winding; effective turns with a known value also denotes ratio-turn with ,known value between its tapping winding and winding with any other fixed turns 2.0.7 Non-uniform insulation of a transformer winding When neutral terminal of the transformer winding is grounding directly or indirectly, the insulation level of its neutral terminal shall be lower than those specified by the circuit terminal 2.0.8 Uniform insulation of a transformer winding Leading-out terminal with all the transformer windings and terminals connecting together shall be provided with same rated insulation level 2.0.9 Shunt inductor Reactors parallel connected on the system are mainly used for the compensation of capacitance current 2.0.10 Arc-suppression coil Single-phase reactor connecting between neutral point of the system and the ground is used for the compensation of grounding capacitance current caused by single-phase earth fault of the system 2.0.11 Instrument transformer It refers to a general designation of the current transformer, electromagnetic voltage transfonner, capacitance voltage transformer (CVT) and transformer combinations (including the combination of single-phase transformers and the combination of three-phase transfor~ners) As the combination of transformer is based on current transformer and electromagnetic voltage transformer combination, correlation testing shall refer to projects of current transformer and voltage transformer t 2.0.12 Voltage transformer Including electromagnetic voltage transformer and CVT; if no special explanation is given out, voltage transformer is usually referring to the electromagnetic voltage transformer 2.0.13 Grounding electrode Metal conductor buried in the earth and contact with the earth directly < 2.0.14 Grounding conductor Conductive metal parts for electrical equipment, grounding terminal of the facilities and grounding electrode 2.0.15 Grounding connection Sum of grounding conductor and grounding electrode 2.0.16 Grounding grid It is a horizontal netty grounding connection with larger scale for power plant and transformer substation composed of vertical and horizontal grounding electrode It also has functions of leakage flow and voltage-sharing 2.0.17 Large-scale grounding connection 1lOkV and above voltage substations, thermal power plant and hydraulic power plant with equipped capacitor of 200MW and above or grounding connection with equivalent plain area is within 5000m2 and more Synchronous generator and rotary condenser 3.0.1 The pilot project for synchronous generator and rotary condenser with'6000kW capacity and above shall include the followingcontent: Insul?tion resistance and ahsorptance polarization index measuring stator winding; Direct current resistance measuring stator winding; DC withstand voltage test and leakage current mensuration of the stator windings; Alternating Current (AC) withstand voltage test of the stator winding; Insulation resistances measuring the rotor windings; DC resistance measuring the rotor winding; AC withstand voltage test of the rotor winding; Mensuration of insulation resistance of excitation circuit of the generator or exciting dynamo and their connecting devices, excluding generator rotor and exciter armature; AC withstand voltage test of excitation circuit of the dynamo or exciting dynamo and their connecting devices, excluding generator rotor and exciter armature; 10 Measure insulation resistance of generator, insulated hearing and rotor water inflow bearing of the exciting dynamo; 11Inspection of embedded temperature detector; 12 Measure DC resistance of field-suppressing resistor and self-synchronizing resistor; 13 Measure alternating-current impedance and power loss of the rotor winding (brushlesg excitation unit may not be measured when measurement conditions are unavailable); 14 Measure and record three-phase short-circuit characteristic; 15 Measure and record no-load characteristic; 16 Measure de-excitation time-constant and over-voltage multiple of the rotor whet1 generator stator is open circuit; 17 Measure the stator residual pressure after switching with the automatic excitation cut-off device of the generator; 18 Measure phase sequences 19 Meas'i~reshaft voltage; 20 Natural-vibration frequency test and modal analysis on stator winding end; 21 Applying volts D.C on wrapped insulation for the stator winding end Note: Synchronous generator with IkV and less voltage shall be tested according to items 1,2,4, 5, , , , , 11, 12, 13, 18 and 19 regardless of its capacity Rotato~ycondenser without starter motor or starting motor of rotary condenser only allows short-time running may not be tested as item 14and 15 3.0.2 Mensuration for insulation resistance and absorptance or polarization index of the stator winding stator shall be in accordance with the following requirements: 1Unbalance factor of various phases of insulation resistance shall not be larger than 2; Absorptance: insulation of asphalt gumming and baked mica shall not be less than 1.3; insulation of epoxy mica powder shall not be less than 1.6 The machine set with capacity of 200MW and more shall be measured polarization index and the polarization index is less than 2.0 Note: Insulating of the machine winding shall meet the requirement specified in this section before making AC withstand Circuit pale-tower with overhead It shall follow the following requirements when the height of the pole-tower is less than 40rn; it shall take ground wire value of 50% of the following values, but it may take value to 20R when the soil resistivity is larger than 2000 0.m and the impedance ground is diEcult to reach 150 The impedance ground is I o n when the soil resistivily5 500O.m The impedance ground is n when the soil resistivity is among 500-1000 n.m < The impedance ground is n when soil resistivity is among 1000-2000 O m The impedance ground is 0 when the soil resistivity> 2000 a m Arrester, at leading-in section on Should not be larger than 3Q rotating machine that is directly couoled with overhead line Circuit pole-tower without overhead ground wire I Reinforced concrete pole and metal pole of non-effective grounding system: impedance ground should not I be larger than 30R Reinforced concrete pole and metal pole in the circuit of neutral-point ungrounded lowtension network: impedance ground should not be larger than 500 Impedance ground of insulator iron feet in the low-voltage house-service wire: impedance ground should not be larger than 300 Note: The extended grounding grid shall be tested after being connected wlth the original grounding gnd 27 Low-voltage electrical apparatus 27.0.1 The test items of low-voltage electrical apparatus shall include followitlg contents: Measure the insulation reiistance of the low-voltage electrical apparatus and the cable and secondary circuit connected with it; < Check the operating value of voltage coil Check the movement condition of low-voltage electrical apparatus; Set the trip adopted by the low-voltage electrical apparatus; Measure the direct-current resistance of resistor and regulator; The alternate withstand voltage test of the low-voltage electrical apparatus and the cable and secondary circuit connected with it Note: The low-voltage electrical apparms include such as the disconnecting switch with voltage among 60-1200 v, changeover, fuse recloser, contactor, controller, electric command device, s M e r , resistor, regulator and electmmagnet; As for the lory-voltage electrical apparatus installed at the loading site of the first and second grade, the test shall be gone on according to Items 2,3 and of this section 27.0.2 Measure the insulation value of the low-voltage electrical apparatus and the cable and secondary circuit connected with it, and the insulation value shall not be less than MQ; it may no less than 0.5 MQ in the relatively wet place 27.0.3 The check of the operating value of voltage coil shall be in accordance with undermentioned provisions: the pull-in voltage of coil shall not be larger than 85% of its nominal voltage, its release voltage shall not be less than 5% of its nominal voltage; The closing coil in short-term operation shall be within the scope of 85%-110% of the nominai voltage, and the shunt excitation coil shall be able to have reliable operation within the scope of 75%-110% of the nominal voltage 27.0.4 The check of the movement condition of low-voltage electrical apparatus shall be in accordance with the undermentioned provisions: as for the electrical apparatus adopting the driving mode with electromotor, hydraulic pressure or air pressure, except that the product has the additional provisions, the electrical apparatus shall operate reliably when the voltage, hydraulic pressure or air pressure are within the scope of 85%-110% of the nominal value 27.0.5 As for the setting the trip adopted by the low-voltage electrical apparatus, all manners of overcurrent trips, decompression and shunted excitation trip and the time-delay devices shall be set according to the operating requirements 27.0.6 Measure the direct-current resistance values of the resistor and the regulator, and their difference shall separately comply with the provisions specified on the product technology conditions And the ohmic value shall meet the requirements on the use of circuit 27.0.7 The alternate withstand voltage test of the low-voltage electrical apparatus and the cable and secondary circuit connected with it shall be in accordance with the following provisions: the testing voltage is 1000V And it may replace it with 2500V megger when the insulation value in the circuit is above 10 MQ, the duration time of test is Appendix AVoltage Standard for the Power Frequency Withstand voltage Test of the Insulatiqn of High-voltage Electrical Appliance Table A Voltage S t a n d a r d f o r t h e P o w e r Frequency Withstand Voltage Test of t h e Insulation of High-voltage Electrical Appliance Effective value ofwithstand voltage (kV) with lmin power frequency Equipment" GB 11.1 for the routine test voltasc of the electrical appliances in the table; The data in the parentheses are the interturn insulation level of the voltage transformer in all-insulation structure: The data up and down the diazonal are the value of the insulation level which base on the ex-factory (nameplate) value Appendix B the Reduction Coefficient of Ohmic Value Recalculation for the Winding Insulation of Electric Machine Stator-to Working Temperature B.O.l Refer to Table B.O.l for the reduction coefficient of the ohmic value recalculation for , winding insulation of electric machine stator-to working temperature Table B.O.1 Reduction Coefficient of the Ohmic Value Recalculation for Winding Insulation of Electric Machine Stator-to Working Temperature Stator winding temperature (T) Reduction 'Thermoplastic coefficient K insulation ' B grade heat-cured 70 60 50 40 30 20 10 1.4 2.8 5.7 11.3 22.6 45.3 90.5 128 4.1 6.6 10.5 16.8 26.8 43 68.7 87 insulation The working temperature in Table B.O.l is 75'C for the thermoplastic insulation and is 100'C for the B grade heat-cured insulation B.0.2 When measuring under different temperatures, it shall carry on the recalculation according to the temperature reduction coefficient listed in Table B.0.1 For example, if the insulation value of one thermoplastic insulation generator is 100 MQ when t= 1O0C,then the insulation value is 100/K=100/90.5=l.l MQ when it is recalculated to when t= 7572 It may also be recalculated according to the following equation: As for the thermoplastic insulation Rt=Rx2 (75-t)'10 (MQ) (B.o.2-1) - As for the B grade heat-cured insulation o Rt=Rx 1.6 ( ~ o o - t ) i ~(MS1) Where R- Insulation value of winding under thermal state; Rt- Ohmic value of winding insulation when the temperature is t'C; t- ~ e m ~ e r a t uwhen r e measures (B.0.2-2) Appendix C Test Method for PartiaI Discharge of Transformer C.O.l The transformer with voltage grade is 110 kV and above 110 kV- shall have the measuring test of the long-term induced voltage and partial discharge, the added voltage, the pressing time and the apparent quantity of electric charge in partial discharge are in accordance with the following requirements: It recommends that the three-phase transformer adopt single-phase connection mode to ,add the voltage on the line terminator phase by phase for the test The application of voltage shall be gone on as Figure C.O.l showed Figure C.O.1Voltage Adding Procedure of the Measurement and Test for the Long-term Induced Voltage and Partial Discharge of Transformer Note: A = jmin; B = jrnin; C = testing time; D>_60min(as for Um>_3OOKV) or 30 (as for Um300kV) or 30min (as for Um000kv) for measuring the partial discharge; The voltage reduces to 1.1Um 143 and keeps for 5min; It shall cut off the power only after the voltage has reduced to less than U213 Except the duration time of UI, the other test duration time has no relation to the test frequency In the whole period of adding the testing voltage, it shall monitor the partial discharge amount Voltage value to earth shall be: U, =1.7Um 143 (C.O.1) U = 1.5Um 143 or 1.3Um 143 , which is determined according to the test conditions IT shall measure background noise level of all the measuring channels before and after applying the testing voltage ' In the that the voltage rises to U2 and reduces from Uz, it shall record the partial discharge inception and extinction voltage that may arise, Measure the apparent charge amount.of partial discharge under ~ m d ; Read and record one reading in the first stage of voltage UZ And the apparent charge amount is not specified in this phase; < The apparent charge amount is not required to be given out in the period of applying Ui; In the whole period of the second phase of voltage U2, it shall observe the partial discharge level continuously and record once every other 5min It passes the test if it meets the following requirements: Testing voltage has no sudden descending; In the long-term test period with U2 = 1.5Udd3 or 1.3umld3, the continuous level of partial discharge amount is no larger than 500pC or 300 PC; Under U2, the partial discharge presents no persist increasing trend and the pulse with higher amplitude value that happens by accident may be not recorded , continuous level of apparent charge amount is no larger than 1OOpC Under l ~ m / ' / the Note: Urn is the effective value of equipment maximum voltage C.0.2 Both the test method and the judgment method when the discharge amount exceeds the forementioned provision shall be gone on according to the relevant regulations in the current national standard '!Power transformers Part 3: Insulation Levels, Dielectric Tests and External Clearances in Air" GB 1.94.3 Appendix D Reference Value for the DC Leakage Current of Oil-immersed Power Transformer Winding Table D Reference Value for the DC Leakage Current of Oil-immersed Power Transformer Windinn Nominal voltage (kv) Peak value of testing Leakage current value of winding under the following temperatures (PA) voltage [kV) 10.C 220% 3VC 440% 50% 60% 70% 80% Appendix E Measuring Method for the Current Transformer Excitation Cuwe of Protection Level E.O.l Measurement and check of P grade excitation curve shall meet the following < requirements: Verify that whether the exact limitation coefficient of the protected level (Grade P) of current transformer meet the requirements on excitation curve measurement and secondary-load modeling method these two indirect methods Excitation curve measurement V-I (excitation) curve of P grade winding shall determine the applying voltage according to the nameplate parameter of current transformer, the secondary resistance r2 may be replaced with secondary direct-current resistance r2, the leakage reactance x2 may be estimated, and the measurement of voltage and electric current uses root-mean-square value instrument The voltage grade shall be different from the estimation Refer to Table E.O for the estimated value of x2: Table E.O.l Estimated Value o f x, Nominal voltage of current transfiimer Unit construction ' Estimated value of xz (Q) CIS And bushing stNcNre 45kV 66-11OkV 220-500kV 0.1 0.15 0.2 0.1 For example: Parameters: nominal voltage of current transformer is 220 kV, transformation ratio of the' tested winding is 1000/5A, and secondary rated load is 50VA, cos@=0.8, 10P20, then: Resistance of nominal secondary load ZL= (50VAl5 A t A ) (0.8+j0.6) =1.6 +j1.2Q Secondary resistance 22% +jx2=0.1+j0.2 111which is the measured value of DC resistance And then the coil generated voltage under 20 times' nominal current according to the given nameplate parameter "10P20": E l 2orn=20~51 (Z2+ZL)l=10011.7+j1.4j= 100 (1.7' +1.4') =220V If the measured exciting current IO>O.lx20x 5A= 10A when applying field voltage 220V at the secondary winding end, it suggests that the exact limitation coefficient of this winding is unqualified Secondary-load modeling method When having the intrinsic error test, the corresponding allocated modeled secondary load may indirectly check up whether the exact limitation coefficient meets the requirements, for example: The nameplate parameter of current transformer is the same as above, change the value of secondary load Z 'L to (20-1) Z2+20 ZL in the circuit for testing the current transformer intrillsic error with normal differential technique, that is: Z '~=(20-1)Z2 +20 ZL= 19 x(O.l+jO.2) + ZO(1.6 + j1.2) = 33.9 + j27.8Q (E.0.1) When the composite error Z ~ ~ d (+6'f%) of the measured nominal current (is lOOOA here) with Z 'L connected is larger than lo%, it is judged to be unqualified, in which the unit of , takes centi-arc Note: 1As the measurement with indirect method does not consider the influence that the primary conductor and returning conductor electric current generate the magnetic field interference, the transfonner passing the indirect method measurement is usually verified with direct method again, and the it is not always qualified, the transformer the has not passed the indirect method measurement will not pass the direct method measurement basically, but the indirect measuring method is simple and < feasible if there is any doubt, it should measure the composite error with direct method and decide whether it is qualified according to the measurement result E.0.2 The recheck for the transient characteristics of current transformer shall meet the following requirements: nominal voltage is 330kV and the voltage grade above 330kV is of independent type, GIs and bushing current transformer, the bus bar current transformer with line capacity is 30x104kw and above this as well as the current transformers of different voltage grades with transient performance in the transformer substation where the capacity ~ , as for its winding that is with transient characteristics requirement, exceeds x l ~ kand it shall adopt low frequency method or flow-through method to measure it relevant parameters and verify whether it meet the related requirements .1 AC-method Apply practical sine-wave alternating voltage on the secondary terminators and measure the corresponding exciting current, the test may be gone on with under-frequency to prevent the winding and the,secondary terminator from bearing the voltage that can not be allowed Measure the exciting current with peak-reading instrument to make it correspondent with the flux value phase of the peak value Measure the field voltage with average -value instrument but the scale is root-mean-square value Secondary flux-linkage passage @ may be calculated according to the following equation with the root-mean-square value U ' of the measured applied-voltage with the frequency f ' : (E.0.2-1) @= d212zf '.u ' (Wb) The root-mean-square value U of equivalent voltage with normal frequency is: U=(2rf/d2).0 (V,r.m.s.) (E.0.2-2) The final exciting characteristic curve is the relation curve between the exciting current i , of peak value and the root-mean-square value U of normal frequency equivalent voltage that represents the peak value passageway @ Magnetizing inductance is determined by the average gradient of the forementioned curve within scope of 20% to 90% of the saturation flux Q,: ~m=@s/i,=(d2) U/(2xfim)(H) (E.0.2-3) When neglecting the secondary side leakage reactance, the secondary time constant Ts corresponding to the total resistive load (kt+%) may be calculated according to the following equation: Ts=L s/Rs=L m/(%, + Rb) (s) (E.0.2-4) When determining the remanence coefficient Kr with AC-method, it requires to integrate the field voltage (see figure E.0.2-2), the integral voltage and the corresponding electric current present hysteresis ]loop on the X-Y scope If the exciting current is the value the saturation flux cDs has reached, the flux value is the remanence cD r when the electric current zero-crossing According to the equation cD,/cD,=yrJyr,, the remanence coefficient K, can be ~alculatedwith the ratio DC-method The DC saturation method refers to adopting a certain DC voltage which can make the flux reach and %eeps at the same value The slow rising of exciting current means that, under the influence of wire-wound resistor voltage, the magnetic-flux measurement value is calculated by integrating the value got by subtracting the voltage at the coil ends of excitation by the additional voltage corresponding to %i, Refer to Figure E.0.2-3 for the model test circuit When measuring the excitation characteristics, it shall close the Switch S immediately after restoring the integrator Record the rising value of exciting current and flux until it reach constant, and then cut off the Switch S Refer to Figure E.0.2-4 for the recording chart of the model test of functional relation between the flux cD (t)and exciting current i,(t) and the time t, in which the flux may be represented with Wb or according to the root-mean-square value U (t) of normal frequency equivalent voltage in Equation (E.0.2-2) Magnetizing inductance (Lm) may be calculated by taking the flux cD (t) of some proper point in the excitation curve and divide it by corresponding i, (t), or calculated with the Equation (E.0.2-3) when the flux value is represented with the root-mean-square value U( t) of the equivalent voltage As the TPS and TPX grade current transformers require determining the.average gradieni of cD (i,) characteristics, so it is recommended to adopt X- Y recording instrument Once the Switch S is disconnected, the lessening exciting current shall pass through the secondary winding and the discharge resistance & The flux value reduces along with this, but it will not reduce to zero when the electric current is zero When the selected excitation current I,, makes the flux reaches the saturation value, the surplus flux value is considered as the remanence (D,when the electric current is zero The iron core of TPS and TPX grade current transformers must be demagnetized beforehand, the remanence coefficient (K,) of the demagnetized TPY grade current transformer is determined with ratio cD,/cD, As for the TPY grade current transformer whose iron core is not demagnetized beforehand, its remanence coefficient (K,) may he determined through exchanging the complementation test of the secondary terminal And here the calculation method of remanence coefficient (K,) is the same as above, but it supposes that (Q,) is half of the residual induction that is measured through the test for the second time Figure E.0.2-I Fundamental Circuit Figure E.0.2-2 Determination of Remanence Coefficient Kt with Hysteresis Hoop Figure E.0.2-3 Fundamental Circuit with DC-method t Derived from oscillograph @ f DerivedfromX-Y Oscillograph Figure E.0.2-4 Typical Record Curve Appendix F Test Method and Requirements of the Transposition and Interconnection System of Power Supply Cable F.O.l The D.C withstand voltage test for the ground insulation of the intersection and interconnection system: it must disconnect the overvoltage protector in the sheath during the test Ground all the three cable metallic sheaths at the opposite side in interconnection box to make the insulating ring of insulating joint also is able to hang together for the test, and then apply DC voltage 10 KV between the metal screen or metallic sheath of each section of cable and the ground, the applying time is without breakdown F.0.2 Overvoltage protector of curve-resistance-type sheath Zinc oxide resistance chip: apply reference current on the resistance chip and measure it voltagedrop, that is the D.C reference voltage, and its value shall be within the scope of the product's standard code; The nonlinear resistance chip and the ground insulation resistance of its down-lead: multipled all the down-leads of the nonlinear resistance chip and insulate with the grounding crust, measure the insulation resistance between the down-lead and the crust with IOOOV megger, the value shall not be less than 10 Ma F.0.3 Performance test of the intersection and interconnection system: this method is the mode that is recommended to be adopted, it shall be taken as the specific test project if adopts this method Lay all the connection strap of the interconnection box at normal working positions, pass' the three-phase equilibrium test current about lOOA through the cable conductor of each phase With keeping the test current fixed, measure the electric current and the voltage to earth of the metallic sheath where is nearest to the intersection and interconnection box: Reduce the test current to zero after the measurement and cut off the power supply Reconnect the connection straps in the nearest intersection and interconnection box to simulate the fault connection, and reincrease the test current to lOOA and measure the electric current and the voltage to earth of the metallic sheath at this intersection and interconnection box Reduce the testing voltage to zero after the measurement and cut off the power supply, and lay the connection straps in this intersection and interconnection box to the correct connection positions Finally, raise the test current to IOOA, measure the electric current and the voltage to earth of the metallic sheaths at all the other intersection and interconnection boxes in the cable line The performance of the intersection and i~lterconnectionsystem is satisfying if the test result meets the following requirements: 1) When the connection strap is wrongly connected, the test is able to indicate the existence of extraordinary large electric current through the metallic sheath; 2) When the connection strap is connected exactly, the current value got after the measred electric current of anyone mktallic sheath is multiplied by one coefficient (it is equal to that the current rating of the cable is divided by the abovementioned test current) will not make the reduction amount of the nominal current of cable exceeds 3%; 3) Multiply the measured voltage to earth of the metallic sheath with the coefficient in the forementioned Item 2), the value shall not exceed the maximum value of the specified induced voltage when the cable is in the load nominal current F.0.4 ~ntercobnectionbox Contact resistance: this test is carried after finishing the forementioned test of sheath overvoltage protector Restore the knife switch (or the connection strap) to the normal working position, measure the cokact resistance of the knife switch (or the connection strap) with double bridge, and the value shall not be larger than 20 < Connection position of knife switch (or connection strap): this test is carried after intersection and interconnection system passing the above test and before sealing the interconnection box The connection position is correct If reconnect after discovering the binding error, it must re-measure the contact resistance of the knife switch (connection strap) a; Appendix G Specific Test Project No Table G Specific Test Project Provisions Measure the alternating-current impedance and power loss of the rotor winding 3P.15 Measure the characteristic c u m of three-phase short-circuit 3.0.16 Measure no-load characteristic curve 3.0.17 Measure and record the de-excitation time-constant of generator under no-load nominal voltage when its Stator is at open circuit Contents 3.0.18 Measure the residual voltage ofstator after the automatic excitation cut-off device is opening when the generator is under no-load nominal voltage 3.0.20 Measure shaft voltage 3.0.21 Test and modal analysis of the natural-vibration frequency at ends of stator winding 3.0.22 Measure the &rent-wrapped insulation of stator winding ends by applying DCvoltage 4.0.11 Measure and record the no-load characteristics ofdirect-current generator and the load characteristic curve with the rotor winding as the load I0 - 5.0.5 Measure and record the no-load characteristic curve 11 12 13 - 7.0.12 Deformation test of tmnsformer windins 7.0.14 Measure the long induced voltage test with self discharge of the winding with bushing 9.0.4 Measurement of the self discharee of transformer 14 9.0.9 Error measurement of transformer I The transformer used for gateway measurement (including current transformer, voltage transformer and combined transformer) must have the error measurement, and the errordetecting mechanism (laborataiy) must be the state-authorized legal measurement and testing institution; Tmnsformer used for gateway measurement with voltage grade is 35KV or above 35KV should 15 9.0.12 When the CTVelectromagnetism element can not lead out the medium voltage line because of structure reason, it must have the error test, when there is any doubt on the insulation of condenser divider, it shall unclose the electromagnetism element and lead out the medium voltage line to measure the capacitance and dielectric loss angle tan6 under nominal voltage 16 17 18 19 20 - 18.0.5 Alternate withstand voltage ttest of power supply cable (35KV or voltage grade above 35KV) ) F.0.3 Performance test of intersection and interconnection 19.0.14 Partial discharge test of coupling condenser 25.0.3 Measure the power frequency parameter of the circtlit above 35KV, 26.0.3 Measurement of impedance ground value (grounding grid) 21 In the whole - code 22 In the whole - code 23 In the whole - code AC and DC withstand voltage test of electrical equipments of I IOKV and voltage grade above I IOKV (or high voltage test) ) Partial discharge test of different kinds of electrical equipments SF6 gas and insulating oil test (except the breakdown voltage test) Explanation of Wording in This Standard Words used for different degrees of strictness are explained as follows in'order to mark the differences in executing the requirements in this code: 1) Words