DL/T 1538-2016 Application guide for vacuum on-load tap-changers for power transformers
1 Scope
This standard specifies the performance, protection configuration, test items, test methods, application scope, and operation and maintenance requirements of resistor type vacuum on-load tap-changers.
This standard is applicable to resistor type vacuum on-load tap-changers configured for power transformers of 220kV and below. Vacuum on-load tap-changers for other non-power transformers may refer to this standard or comply with manufacturer’s specifications.
This standard is not applicable to reactor type vacuum on-load tap-changers.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 6451-2015 Specification and technical requirements for oil-immersed power transformers
GB 10230.1-2007 Tap-changers - Part 1: Performance requirements and test methods
GB/T 10230.2-2007 Tap-changers - Part 2: Application guide
GB 11032-2010 Metal-oxide surge arresters without gaps for a.c. systems
GB/T 16927.1 High-voltage test techniques - Part 1: General definitions and test requirements
GB/T 22065 Pressure type SF6 gas density monitor
DL/T 537 High-voltage/low-voltage prefabricated cubical substation
DL/T 574-2010 Guide to the operation and the maintenance of tap-changers in the transformer
DL/T 596-2005 Preventive test code for electric power equipment
JB/T 7065 Pressure relief device for transformers
JB/T 8314-2008 Test guide for tap-changers
JB/T 9647 Buchholz relay
JB/T 10372 Hydraulic fluid power - Pressure switch
JB/T 10892 Electrical SF6 gas density transmitters
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB 10230.1 and GB/T 10230.2 and the following apply.
3.1
vacuum on-load tap-changer
on-load tap-changer that uses vacuum interrupters to break and make the load current and circulating current, with oil (including mineral oil and other flame-retardant or environmentally-friendly alternative oils, hereinafter referred to as "insulating oil") or gas (air or SF6) as the insulating medium of the tap-changer body
3.2
transfer contact (connected with vacuum interrupter)
electrical contact in a vacuum on-load tap-changer that is connected in series with a vacuum interrupter and works together with the vacuum interrupter to complete the tap-changing task
3.3
main switching vacuum interrupter
vacuum interrupter for making and breaking the load current and/or circulating current, with no transition resistor between it and the transformer winding
3.4
transition vacuum interrupter
vacuum interrupter connected in series with a transition resistor, which is capable of making and breaking the load current and/or circulating current
3.5
combined on-load tap-changer
on-load tap-changer that performs tap-change operations through a combination of two parts: a diverter switch and a tap selector
3.6
compound on-load tap-changer
on-load tap-changer that performs tap-change operations by means of a selector switch
4 Classification and installation methods
4.1 Classification of vacuum on-load tap-changers
4.1.1 Classification by presence or absence of main contacts
4.1.1.1 Vacuum on-load tap-changer with main contacts
The diverter switch or selector switch is equipped with independent main contacts for carrying the load current on a long-term basis. The main switching vacuum interrupter only performs the task of making/breaking the working current during switching operations. Upon completion of switching operation, the load current is still carried by the main contacts. See A.1 for a typical schematic diagram.
4.1.1.2 Vacuum on-load tap-changer without main contacts
The diverter switch or selector switch is equipped with no independent main contacts for carrying the load current on a long-term basis. The main switching vacuum interrupter performs both tasks of carrying the long-term load current and making/breaking the working current. See A.2 for a typical schematic diagram.
4.1.2 Classification by insulating medium
4.1.2.1 Oil-insulated vacuum on-load tap-changer
It refers to an on-load tap-changer that uses insulating oil as the insulating medium and uses vacuum interrupters to break and make the load current and circulating current. The diverter switch or selector switch shall be provided with a separate oil chamber to isolate itself from the insulating oil of the transformer body.
4.1.2.2 Air-insulated vacuum on-load tap-changer
It refers to an on-load tap-changer that uses air as the insulating medium and uses vacuum interrupters to break and make the load current and circulating current. The insulating medium of such a tap-changer is atmospheric air. This type of tap-changer is usually installed on dry-type transformers.
4.1.2.3 SF6-insulated vacuum on-load tap-changer
It refers to an on-load tap-changer that uses SF6 gas as the insulating medium and uses vacuum interrupters to break and make the load current and circulating current. The diverter switch or selector switch shall be provided with a separate gas chamber to isolate itself from the SF6 gas of the transformer body.
4.2 Installation methods for vacuum on-load tap-changers
All installation methods specified in GB/T 10230.2-2007 are applicable to vacuum on-load tap-changers.
China
Contents
Foreword II
1 Scope
2 Normative references
3 Terms and definitions
4 Classification and installation methods
5 Technical performance indicators
6 Motor drive mechanism
7 Protection requirements
8 Selection principles
9 Tests
10 Installation and acceptance
11 Operation
12 Maintenance
13 Inspection and treatment of abnormal conditions
Annex A (Informative) Typical schematic diagrams of diverter switches for vacuum on-load tap-changers
Annex B (Informative) Test items and requirements for vacuum on-load tap-changers that differ from JB/T 8314
Annex C (Informative) Gas filling pressure of SF6 vacuum on-load tap-changers and operating characteristics of gas sudden pressure relays
Annex D (Informative) Typical service conditions and insulation level of on-load tap-changers on power transformers of 220kV and below
Annex E (Informative) Test method for composite waveforms of vacuum on-load tap-changers
DL/T 1538-2016 Application guide for vacuum on-load tap-changers for power transformers
1 Scope
This standard specifies the performance, protection configuration, test items, test methods, application scope, and operation and maintenance requirements of resistor type vacuum on-load tap-changers.
This standard is applicable to resistor type vacuum on-load tap-changers configured for power transformers of 220kV and below. Vacuum on-load tap-changers for other non-power transformers may refer to this standard or comply with manufacturer’s specifications.
This standard is not applicable to reactor type vacuum on-load tap-changers.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 6451-2015 Specification and technical requirements for oil-immersed power transformers
GB 10230.1-2007 Tap-changers - Part 1: Performance requirements and test methods
GB/T 10230.2-2007 Tap-changers - Part 2: Application guide
GB 11032-2010 Metal-oxide surge arresters without gaps for a.c. systems
GB/T 16927.1 High-voltage test techniques - Part 1: General definitions and test requirements
GB/T 22065 Pressure type SF6 gas density monitor
DL/T 537 High-voltage/low-voltage prefabricated cubical substation
DL/T 574-2010 Guide to the operation and the maintenance of tap-changers in the transformer
DL/T 596-2005 Preventive test code for electric power equipment
JB/T 7065 Pressure relief device for transformers
JB/T 8314-2008 Test guide for tap-changers
JB/T 9647 Buchholz relay
JB/T 10372 Hydraulic fluid power - Pressure switch
JB/T 10892 Electrical SF6 gas density transmitters
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB 10230.1 and GB/T 10230.2 and the following apply.
3.1
vacuum on-load tap-changer
on-load tap-changer that uses vacuum interrupters to break and make the load current and circulating current, with oil (including mineral oil and other flame-retardant or environmentally-friendly alternative oils, hereinafter referred to as "insulating oil") or gas (air or SF6) as the insulating medium of the tap-changer body
3.2
transfer contact (connected with vacuum interrupter)
electrical contact in a vacuum on-load tap-changer that is connected in series with a vacuum interrupter and works together with the vacuum interrupter to complete the tap-changing task
3.3
main switching vacuum interrupter
vacuum interrupter for making and breaking the load current and/or circulating current, with no transition resistor between it and the transformer winding
3.4
transition vacuum interrupter
vacuum interrupter connected in series with a transition resistor, which is capable of making and breaking the load current and/or circulating current
3.5
combined on-load tap-changer
on-load tap-changer that performs tap-change operations through a combination of two parts: a diverter switch and a tap selector
3.6
compound on-load tap-changer
on-load tap-changer that performs tap-change operations by means of a selector switch
4 Classification and installation methods
4.1 Classification of vacuum on-load tap-changers
4.1.1 Classification by presence or absence of main contacts
4.1.1.1 Vacuum on-load tap-changer with main contacts
The diverter switch or selector switch is equipped with independent main contacts for carrying the load current on a long-term basis. The main switching vacuum interrupter only performs the task of making/breaking the working current during switching operations. Upon completion of switching operation, the load current is still carried by the main contacts. See A.1 for a typical schematic diagram.
4.1.1.2 Vacuum on-load tap-changer without main contacts
The diverter switch or selector switch is equipped with no independent main contacts for carrying the load current on a long-term basis. The main switching vacuum interrupter performs both tasks of carrying the long-term load current and making/breaking the working current. See A.2 for a typical schematic diagram.
4.1.2 Classification by insulating medium
4.1.2.1 Oil-insulated vacuum on-load tap-changer
It refers to an on-load tap-changer that uses insulating oil as the insulating medium and uses vacuum interrupters to break and make the load current and circulating current. The diverter switch or selector switch shall be provided with a separate oil chamber to isolate itself from the insulating oil of the transformer body.
4.1.2.2 Air-insulated vacuum on-load tap-changer
It refers to an on-load tap-changer that uses air as the insulating medium and uses vacuum interrupters to break and make the load current and circulating current. The insulating medium of such a tap-changer is atmospheric air. This type of tap-changer is usually installed on dry-type transformers.
4.1.2.3 SF6-insulated vacuum on-load tap-changer
It refers to an on-load tap-changer that uses SF6 gas as the insulating medium and uses vacuum interrupters to break and make the load current and circulating current. The diverter switch or selector switch shall be provided with a separate gas chamber to isolate itself from the SF6 gas of the transformer body.
4.2 Installation methods for vacuum on-load tap-changers
All installation methods specified in GB/T 10230.2-2007 are applicable to vacuum on-load tap-changers.
Contents of DL/T 1538-2016
China
Contents
Foreword II
1 Scope
2 Normative references
3 Terms and definitions
4 Classification and installation methods
5 Technical performance indicators
6 Motor drive mechanism
7 Protection requirements
8 Selection principles
9 Tests
10 Installation and acceptance
11 Operation
12 Maintenance
13 Inspection and treatment of abnormal conditions
Annex A (Informative) Typical schematic diagrams of diverter switches for vacuum on-load tap-changers
Annex B (Informative) Test items and requirements for vacuum on-load tap-changers that differ from JB/T 8314
Annex C (Informative) Gas filling pressure of SF6 vacuum on-load tap-changers and operating characteristics of gas sudden pressure relays
Annex D (Informative) Typical service conditions and insulation level of on-load tap-changers on power transformers of 220kV and below
Annex E (Informative) Test method for composite waveforms of vacuum on-load tap-changers
