136k views
4 votes
Two tests were performed on a 230-V, 60-Hz, 4-pole, Y-connected, three-phase induction motor and the obtained data are given in the table below.

The friction and windage loss is 15 W, and the stator winding resistance between any two lines is 3.96ohm. Determine:
1) The equivalent circuit parameters of the motor

No-load test Blocked-rotor test
3-phase power input, W 137 70
Line current, A 0.43 1.18
Line-line voltage, V 230 47

User Simeon G
by
7.3k points

1 Answer

2 votes

Final answer:

To find the equivalent circuit parameters of a Y-connected three-phase induction motor, one must analyze the results from the no-load and blocked rotor tests by calculating the reactance and resistance values using the stator winding resistance and the power factor from these tests.

Step-by-step explanation:

To determine the equivalent circuit parameters of a three-phase induction motor from no-load and blocked rotor test data, we have to analyze the input power, the stator winding resistance, and the current and voltage readings from both tests.

For the no-load test, we can calculate the input reactance by using the power factor of the motor when it operates without load. This involves the calculation of no-load current and no-load power factor.

The blocked rotor test provides the parameters for the equivalent circuit representing the motor at standstill. The blocked rotor reactance and resistance can be calculated using the voltage, current, and input power during the test, along with the stator winding resistance.

It's important to take into account that the tests consider the motor as a Y-connected system and the given stator winding resistance is between two lines, thus it will be divided by √3 for individual phase calculations.

User Arun R
by
7.7k points