1. Line to line sustained short circuit test
Table of Content:
1 Objective........................................................................................................
2 Scope.............................................................................................................
3 Referenced Documents.................................................................................
4 Definitions and abbreviations........................................................................
5 Line to line sustained short-circuit test..........................................................
5.1 Connection (see diagram) ......................................................................
5.2 Machine condition...................................................................................
5.3 Measured quantities ..............................................................................
5.4 Evaluation ..............................................................................................
5.5 Problems ................................................................................................
6 Proceeding in case of deviations..........................................................................
7 Copyright ...............................................................................................................
1 Objective
Determination of negative sequence reactance X2 and negative sequence resistance R2.
2 Scope
All synchronous machines of all kinds, tested in the work shop or at site.
3 Referenced Documents
IEC 34-4, 48-49
IEEE 115, 10.5.4 Method 3
EN 60034-4
4 Definitions and Abbreviations
None
5 Line to line sustained short-circuit test
5.1 Connection (see diagram)
Short-circuit any two line terminals by inserting ampere meter and wattmeter (current
circuit)
Note: It is recommendable to perform this test immediately after the three-phase sustained
short-circuit test, removing the short-circuit between two line terminals. Connect voltmeter
between open line terminal and one of the short-circuited terminals
5.2 Machine condition
Machine is driven at rated speed by turbine or motor resp.
Note: When a prime mover is not available, this test can also be performed by retardation
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2. method, measuring when the decelerating machine passes through nominal speed. Set
excitation level to several values of the short-circuit current up to max. 0,3 In and take
readings.
5.3 Measured quantities
Short-circuit current (I) and field current (If) voltage between open line terminal and short
circuited terminals (U) active power of short-circuit (P)
Note: Measurement of reactive power (Q) is not considered necessary. A special VAr-
meter would be required for measuring Q.
5.4 Evaluation
5.5 Problems
- danger of overheating solid parts
should higher current levels than 0,3 In be stipulated in the contract restrict test duration
to time required for reading of instruments
- danger of excessive vibration
for non-salient pole machines limit armature current in any case to 0,5 In
6 Proceeding in case of deviations
Any nominal value, minimum value, maximum value, tolerance etc given in an instruction
intended to serve for quality control purposes only. In the case of deviations, a
nonconformity report has to be written according to PNG Power Standard.
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3. 7 Χοπψριγητ
This Document is properly of PNG Power internal use only and must neither be copied.
Neither is it to be handed over nor in other way communicated to a third party.
Infringement will lead to prosecution.
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