Simulation of magnetizing inrush currents for single-phase transformers
For designing a digital differential protection system of power transformers using micro-computers, it is very important to test the relay on digitally simulated data for both the fault and magnetizing inrush currents of transformers. Magnetizing inrush is a complicated phenomenon which depends on the various factors like switching angle, residual flux level, core saturation and saturation angles etc. Again saturation angle changes from cycle to cycle. It is, therefore, difficult to ascertain these values by experimental methods. Detailed computer programs have been developed to determine the magnetizing inrush current values by numerical methods. The equivalent circuit parameters are used to simulate digitally the inrush waveshape under definite switching conditions. A point-on-wave switch is designed using a thyristor bridge circuit to switch on a transformer at a specified angle of the applied voltage waveform. Both the measured and simulated waveshapes are presented. Flow charts are given to explain the programming routines which are necessary for modelling these current waveshapes. There exists a close agreement between the simulated and actual values of a laboratory model transformer.
- Research Organization:
- Federal Pioneer Ltd., Toronto, Ontario
- OSTI ID:
- 6059927
- Journal Information:
- Int. J. Energy Syst.; (United States), Vol. 7:1
- Country of Publication:
- United States
- Language:
- English
Similar Records
Elimination of inrush current of transformers and distribution lines
Study of differential protection with current transformers of the new types