Question

A 15 KVA, 440/230 V, 50 Hz, single phase transformer gave the following test results: Open Circuit (LV side) 250 V, 1.8A, 95 W. Short Circuit Test (HV side) 80 V, 12.0 A, 380 W. Compute the parameters of the equivalent circuit referred to LV side.

Answer 1

To calculate the parameters of the equivalent circuit referred to the LV side of the transformer, we use the test results from the open circuit and short circuit tests. The parameters include reactance, resistance, and magnetizing branch components.

Step-by-step explanation:

Given the information provided, we can calculate the parameters of the equivalent circuit referred to the LV (low voltage) side of the transformer.

The open circuit test on the LV side gave a voltage of 250 V, a current of 1.8 A, and a power of 95 W. The short circuit test on the HV (high voltage) side gave a voltage of 80 V, a current of 12.0 A, and a power of 380 W.

Using these test results, we can calculate the equivalent circuit parameters as follows:

1. Reactance (X): The reactance can be calculated using the formula: X = VL / IL. Therefore, X = 250 V / 1.8 A = 138.8 ohms.
2. Resistance (R): The resistance can be calculated using the formula: R = Pshort / (Ishort)2. Therefore, R = 380 W / (12.0 A)2 = 2.65 ohms.
3. Magnetizing branch components: The magnetizing branch components can be calculated using the formulas: Zmagnetizing = |Vopen| / |Iopen| and Rmagnetizing = cos(θ) * Zmagnetizing. Therefore, Zmagnetizing = |250 V| / |1.8 A| = 138.9 ohms and Rmagnetizing = cos(θ) * 138.9 ohms.

These are the parameters of the equivalent circuit referred to the LV side of the transformer.