What are the reasons in conducting no load test with rated voltage and blocked rotor test with rated current?

1. To obtain the variation of no load power and current and blocked rotor power and current with changes in the applied voltage to the stator. 2. To determine the equivalent circuit parameters of an induction motor.

Why rated voltage is applied in no load test?

No-Load test or Open-Circuit Test: The motor is not connected from its load, and the rated voltage at the rated frequency is applied to the stator to run the motor without a load. Since the motor is running at no-load, total power is equal to the constant iron loss, friction and winding losses of the motor.

Why blocked rotor test are used?

Blocked rotor test or short circuit test: It is used to find out series branch parameters (R01 and X01) of equivalent circuit parameters when referred to the primary side (stator) and the full load copper losses (I2R).

How the voltage is received in the rotor of induction motor?

Operating principle. In a three-phase induction machine, alternating current supplied to the stator windings energizes it to create a rotating magnetic flux. The flux generates a magnetic field in the air gap between the stator and the rotor and induces a voltage which produces current through the rotor bars.

How should the rotor voltage be with respect to the high voltage and large machines?

How should the rotor voltage be with respect to the high voltage and large machines? Explanation: The high voltage and large machines should have high rotor voltage. If the rotor voltage is kept low, the rotor current becomes large, involving use of large conductor sections.

What is the method used to supply rotor voltage?

By injecting EMF in rotor circuit In this method, speed of an induction motor is controlled by injecting a voltage in rotor circuit. It is necessary that voltage (emf) being injected must have same frequency as of the slip frequency.

What do you mean by blocked rotor test?

In the blocked rotor test, the rotor is locked securely enough that it cannot break free. A low voltage is applied on the stator terminals so that there is full load current in the stator winding, and the current, voltage and power input are measured at that point.

What three factors determine the amount of voltage induced in the rotor of a wound rotor motor?

Strength of magnetic field of stator.

Strength of magnetic field of rotor.

Phase angle difference between stator flux and rotor flux.

What is the rotor winding for round rotor motor?

What is the rotor windings for wound rotor motors? Explanation: The rotor windings for wound rotor motors are 3 phase windings. The number of rotor slots should be such that a balanced winding is obtained. 2.