GB/T 24840-2018Technical specification for bushings of 1000kV AC system (English PDF)

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009.

This standard replaces GB /Z 24840-2009 "Technical Specification for Casing for 1000kV AC System".

Compared with GB /Z 24840-2009, the main technical changes of this standard except for editorial changes are as follows.

--- Added the terminology and definition of "oil-SF6 casing" (see 3.4);

--- Remove the requirement for voltage taps in the full text of the standard;

--- Revised the typical parameter values of "tolerance to earthquakes" in Table 1, and proposed waters corresponding to seismic fortifications of 6, 7, and 8 respectively. Flat acceleration and vertical acceleration values (see Chapter 4, Chapter 4 of the 2009 edition);

---Modified the short-time power frequency withstand voltage test time in the rated insulation level of transformer bushing, modified from 1min to 5min (See 6.2, 6.2 of the 2009 edition);

--- Removed the details of the performance requirements of the shed and jacket material of the composite casing (see 7.3 of 2009 edition);

--- Removed the details of the pipe material performance requirements of the composite casing (see 7.4 of the 2009 edition);

--- Removed the maximum requirement for dielectric loss factor of gas-insulated bushings (see 7.5 of 2009 edition);

--- Modified the partial discharge measurement voltage value of the bushing, and changed "1.05Um/3" to "1.1Um/3" (see 7.6, 2009 edition) 7.6);

---Modified the dielectric loss factor limit requirement of the test tap, and changed "tan delta <= 0.03" to "tan delta <= 0.02" (see 7.8, 2009 edition) 7.9);

--- Add the moisture content requirements of new inflated bodies and operating gases in the "Gas Insulation Inside Gas Performance" entry (see 7.13);

--- The oil-SF6 casing test requirements have been added to the test requirements (see 8.1);

--- Revised the lightning impulse dry withstand voltage test requirements, distinguishing the type test and the test procedure one by one (see 8.3, 2009 edition) 8.4);

--- Modified the test voltage value in the long-term power frequency withstand voltage program, and modified the highest test voltage 1.7Um/3 to Um (see 8.5, 7.7 of the 2009 edition;

--- Revised the sealing test requirements for oil-filled insulating bushings and increased the type test requirements (see 8.13, 7.12 of the 2009 edition);

--- "The long-term power frequency withstand voltage of the transformer type casing" "The thermal stability of the casing" "The sealing test of the oil-filled insulating sleeve" and The contents of the "Insulation Test for Insulating Bushings" entry are moved to the "Test Requirements and Methods" section (see Chapter 8, 2009 Edition). 7.7, 7.10, 7.12, 7.13);

--- Revised the type test project sequence and adjusted the temperature rise test to the internal pressure test (see 9.2, 9.2 of the 2009 edition);

--- The type of casing type test item is changed to "measurement terminal capacitance and tan delta measurement" to "test tap insulation test" (see 9.2, 9.2) of the 2009 edition;

--- Increased long-term performance test of casing (see 9.3).

1 Scope

This standard specifies the technical performance requirements of the casing for 1000kV AC system, one test, type test and on-site handover test.

This standard applies to 1000kV voltage for 1000kV AC system transformer equipment and gas insulated metal-enclosed switchgear. Grade casings, sleeves for other equipment can be used as reference.

2 Normative references

The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this document. For undated references, the latest edition (including all amendments) applies to this document.

GB/T 2423.23-2013 Environmental testing - Part 2. Test method test Q. Sealing

GB/T 2900.5 Electrotechnical terminology for insulating solids, liquids and gases

GB/T 2900.8 Electrotechnical terminology insulator

GB/T 4109-2008 Insulating bushings with AC voltage higher than 1000V

GB/T 11022-2011 Common technical requirements for high voltage switchgear and control equipment standards

GB/T 16927.1-2011 High voltage test techniques - Part 1. General definitions and test requirements

GB/T 21429-2008 Definitions, test methods, acceptance criteria and design of hollow composite insulators for outdoor and indoor electrical equipment recommend

GB/T 23752-2009 Pressure-bearing and non-pressure-bearing hollow porcelain and glass insulators for electrical equipment with rated voltages above 1000V

GB/T 26218 (all parts) Selection and sizing of high-voltage insulators used under dirty conditions

DL/T 1277-2013 Technical specification for 1100kV AC hollow composite insulator

DL/T 1408-2015 1000kV AC system oil - sulphur hexafluoride bushing technical specification

3 Terms and definitions

The following terms and definitions as defined in GB/T 2900.5, GB/T 2900.8, GB/T 4109-2008 apply to this document.