IEC 60270:2000 pdf High-voltage test techniques – Partial discharge meas urements

IEC 60270:2000 pdf High-voltage test techniques – Partial discharge meas urements
1 Scope
This International Standard is applicable to the measurement of partial dis charges 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 dis charges from external
interference.
The provisions of this standard should be used in the drafting of specifications relating to
partial dis charge measurements for specific power apparatus. It deals with electrical
measurements of impulsive (short-duration) partial dis charges , but reference is also made to
non-electrical methods primarily used for partial dis charge location (see annex F).
Diagnosis of the behaviour of specific power apparatus can be aided by digital processing of
partial dis charge data (see annex E) and also by non-electrical methods that are primarily
used for partial dis charge location (see annex F).
This standard is primarily concerned with electrical measurements of partial dis charges made
during tests with alternating voltage, but specific problems which arise when tests are made
with direct voltage are considered in clause 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.
Annex A provides normative requirements for performance tests on calibrators.
2 Normative references
The following normative documents contain provisions which, through reference in this text,
constitute provisions of this International Standard. For dated references, subsequent
amendments to, or revisions of, any of these publications do not apply. However, parties to
agreements based on this International Standard are encouraged to investigate the possibility
of applying the most recent editions of the normative documents indicated below. For undated
references, the latest edition of the normative document referred to applies. Members of IEC
and ISO maintain registers of currently valid International Standards.
IEC 60060-1, High-voltage test techniques – Part 1: General definitions and test requirements.
IEC 60060-2, High-voltage test techniques – Part 2: Measuring systems
CISPR 16-1:1993, Specification for radio disturbance and immunity measuring apparatus and
methods – Part 1: Radio disturbance and immunity measuring apparatus
3 Definitions
For the purpose of this International Standard, the following definitions apply.
3.1 partial discharge (PD)
localized electrical discharge that only partially bridges the insulation between conductors and
which can or can not occur adjacent to a conductor
NOTE 1 Partial discharges are in general a consequence of local electrical stress concentrations in the insulation or on the surface of the insulation. Generally, such discharges appear as pulses having a duration of much less than 1 µs. More continuous forms can, however, occur, such as the so-called pulse-less discharges in gaseous dielectrics. This kind of discharge will normally not be detected by the measurement methods described in this standard.
NOTE 2 “Corona” is a form of partial discharge that occurs in gaseous media around conductors which are remote from solid or liquid insulation. “Corona” should not be used as a general term for all forms of PD.
NOTE 3 Partial discharges are often accompanied by emission of sound, light, heat, and chemical reactions.
For further information, see annex F.
3.2 partial discharge pulse (PD pulse)
current or voltage pulse that results from a partial discharge occurring within the object under
test. The pulse is measured using suitable detector circuits, which have been introduced into
the test circuit for the purpose of the test
NOTE A partial discharge which occurs in the test object produces a current pulse. A detector in accordance with the provisions of this standard produces a current or a voltage signal at its output, proportional to the charge of the current pulse at its input.