1. Short Circuit Current Calculation:-
● Fault Analysis: The short circuit impedance value helps calculate the fault current that can flow through the transformer during a short circuit event. This information is crucial for selecting appropriate protective devices like circuit breakers and fuses.
● System Design: It aids in designing the electrical system by ensuring that the protective devices are capable of interrupting the fault current within the specified time.
2. Transformer Losses:-
● Copper Losses: The test allows for the determination of the copper losses within the transformer windings. These losses occur due to the resistance of the windings and contribute to the overall efficiency of the transformer.
● Efficiency Calculation: By knowing the copper losses, along with the core losses determined from the open circuit test, the overall efficiency of the transformer can be calculated.
3. Voltage Regulation:-
● Voltage Drop: The short circuit impedance test helps estimate the voltage drop across the transformer under full load conditions. This information is essential for maintaining a stable voltage level at the load end, even when the transformer is heavily loaded.
4. Parallel Operation:
● Load Sharing: The short circuit impedance values of two or more transformers are compared to ensure proper load sharing when they are connected in parallel. Unequal impedance values can lead to uneven load distribution, potentially overloading one transformer.
5. Mechanical Strength:
● Electromagnetic Forces: The test indirectly assesses the mechanical strength of the transformer windings. During a short circuit, significant electromagnetic forces are generated, which can potentially damage the windings. The test helps ensure that the windings are robust enough to withstand these forces
. 6. Transformer Rating and Cost:
● Design Optimization: The short circuit impedance value influences the design and cost of the transformer. A higher impedance value generally leads to lower short circuit currents but also higher voltage drops and copper losses.
● Economic Considerations: The test helps in optimizing the transformer design to achieve a balance between performance and cost.
