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A method of predicting transient constants of synchronous machines
Author(s) -
Ara Takahiro,
Akima Tsunaki,
Oda Shoichi
Publication year - 1996
Publication title -
electrical engineering in japan
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.136
H-Index - 28
eISSN - 1520-6416
pISSN - 0424-7760
DOI - 10.1002/eej.4391160112
Subject(s) - armature (electrical engineering) , reactance , transient (computer programming) , control theory (sociology) , time constant , short circuit , equivalent circuit , short circuit ratio , electronic circuit , voltage , mechanics , electrical engineering , electromagnetic coil , physics , engineering , computer science , control (management) , artificial intelligence , led circuit , operating system
It is difficult to determine the subtransient (transient) reactance and subtransient (transient) short‐circuit time constants of medium and large synchronous machines by the sudden three‐phase short‐circuit test because large‐capacity equipment is required. This paper describes a new method of measuring these constants by means of a simple test using a small dc power supply. The key points of this method are as follows. (1) A dc voltage is applied to the armature winding (two terminals with the third one open) of a stationary synchronous machine through a resistance. When the two terminals are closed, the winding is short‐circuited and the current in the armature winding decays. The whole process of decaying current is recorded. (2) The value of the transient phenomena of the winding calculated from circuit equations (armature, field winding and damper winding circuits) is compared with actual data, and the unknown equivalent circuit constants are identified by the least squares method. (3) Transient phenomena of the sudden three‐phase short‐circuit are calculated by the two‐reaction theory using identified constants, and, hence, these constants are calculated. The transient constants of synchronous machines obtained by the new method agree closely with the observed values.