1 Scope
This Standard is applicable to the measurement of partial discharges which occur in electrical apparatus, components or systems when tested with alternating voltages up to 400 Hz or with direct voltage.
This Standard:
— Defines the terms used;
— Defines the quantities to be measured;
— Describes test and measuring circuits which may be used;
— Defines analogue and digital measuring methods required for common applications;
— Specifies methods for calibration and requirements of instruments used for calibration;
— Gives guidance on test procedures;
— Gives some assistance concerning the discrimination of partial discharges from external interference.
The provisions of this standard should be used in the drafting of specifications relating to partial discharge measurements for specific power apparatus. It deals with electrical measurements of impulsive (short-duration) partial discharges, but reference is also made to non-electrical methods primarily used for partial discharge location (see Appendix F).
Diagnosis of the behaviour of specific power apparatus can be aided by digital processing of partial discharge data (see Appendix E) and also by non-electrical methods that are primarily used for partial discharge location (see Appendix F).
This standard is primarily concerned with electrical measurements of partial discharges made during tests with alternating voltage, but specific problems which arise when tests are made with direct voltage are considered in Chapter 11.
The terminology, definitions, basic test circuits and procedures often also apply to tests with other frequencies, but special test procedures and measuring system characteristics, which are not considered in this standard, may be required.
Appendix A provides normative requirements for performance tests on calibrators.
2 Normative References
Foreword III
1 Scope
2 Normative References
3 Definitions
3.1 Partial discharge (PD)
3.2 Partial discharge pulse (PD pulse)
3.3 Quantities related to partial discharge pulses
3.4 Largest repeatedly occurring PD magnitude
3.5 Specified partial discharge magnitude
3.6 Background noise
3.7 Applied test voltages related to partial discharge pulse quantities
3.8 Partial discharge measuring system
3.9 Measuring system characteristics
3.10 Digital partial discharge instruments
3.11 Scale factor k
4 Test Circuits and Measuring Systems
4.1 General requirements
4.2 Test circuits for alternating voltages
4.3 Measuring systems for apparent charge
4.4 Requirements for measurements with digital PD-instruments
4.5 Measuring systems for derived quantities
4.6 Ultra-wide-band instruments for PD detection
5 Calibration of a Measuring System in the Complete Test Circuit
5.1 General
5.2 Calibration procedure
6 Calibrators
6.1 General
6.2 Calibrators for the calibration of a measuring system in the complete test circuit
6.3 Calibrators for performance tests on measuring systems
7 Maintaining the Characteristics of Calibrators and Measuring Systems
7.1 Schedule of tests
7.2 Maintaining the characteristics of calibrators
7.3 Maintaining the characteristics of measuring systems
8 Tests
8.1 General requirements
8.2 Conditioning of the test object
8.3 Choice of test procedure
9 Measuring Uncertainty and Sensitivity
10 Disturbances
11 Partial Discharge Measurements During Tests with Direct Voltage
11.1 General
11.2 Quantities related to partial discharges
11.3 Voltages related to partial discharges
11.4 Test circuits and measuring systems
11.5 Tests
Appendix A (Normative) Performance Test on a Calibrator
Appendix B (Informative) Test Circuits
Appendix C (Informative) Measurements on Cables, Gas Insulated Switchgear, Power Capacitors and on Test Objects with Windings
Appendix D (Informative) The Use of Radio Disturbance (Interference) Meters for the Detection of Partial Discharges
Appendix E (Informative) Guidelines to Digital Acquisition of Partial Discharge Quantities
Appendix F (Informative) Non-electrical Methods of PD Detection
Appendix G (Informative) Disturbances
