The design of electrical power systems on offshore platforms involves ensuring the safe and reliable operation of the systems. These criteria prompted the need for performing short-circuit studies and fault level calculations. Using the results obtained from these studies together with the load data, the switchgear rating and fault rating of the switchboard can be determined. This study will aid the designer in determining both transient and substransient reactances of the generators, whereby the transient reactance is used in studying the effect of starting a large motor such as a compressor or a pump and the substransient reactance is used in short circuit studies. The generators parameters are therefore essential in the determination of circuit breaker setting, switchboard ratings and the starting capability of motors. These factors have prompted research into methods for determining the parameters of synchronous generators. The tests approved by the British Standards which are usually employed by manufacturers, however suffer from a number of disadvantages such as the possibility of damage to the generator windings as a result of the sudden three phase short circuit test. On the other hand some of these tests such as the d.c. standstill decay test are quoted as 'unconfirmed testing methods'. This study is therefore aimed at developing a method whereby the parameters of synchronous machines can be estimated directly from the on-line voltage and current waveforms. The study starts by determining the parameters of two salient pole generators using the conventional methods. This is used later to establish the accuracy of the proposed method. The effect of varying the generators parameters on voltage and current waveforms is then analysed, leading to the introduction of a method using only three simple tests. The accuracy and reliability of the method is demonstrated using the software simulator SABER. Finally the new parameter estimating technique is used to determine saturated parameters of the two laboratory generators for different field excitations.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:593388 |
| Date | January 1997 |
| Creators | Salman, S. |
| Publisher | University of Aberdeen |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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