Short Circuit Impedance Calculation of Three-Winding High Impedance Transformer
CHEN Bo-gen
（Fuzhou Tianyu Electric Co., Ltd, Fuzhou 350012, China）
Abstract: Introduction was made to the calculation method of short-circuit impedance, the typical winding arrangement and different operation modes of the three-winding high impedance transformer. This paper gave the change and calculation method of the equivalent magnetic flux leakage path area under various modes of operation and inferred a new method for calculating the equivalent magnetic flux leakage path area when the magnetic flux leakage was divided into two parts with opposite directions, pointing out the relationship between short-circuit impedance and the rated short-circuit impedance of the three-winding high impedance transformer during the limit tap operation. The computed result was compared with the experimental value and the deviation was less that 2%, which shows that the computational formula conforms to the requirements of engineering calculation.
Key words: three-winding high impedance transformer; short circuit impedance; equivalent magnetic flux leakage path area
