Wound induction motor pdf

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Remember me on this computer. Enter the email address you signed up with and we'll email you a reset link. Need an account? Click here to sign up. Download Free PDF. Chapter 7: Induction Motors. Amadou Top. A short summary of this paper. Chapter 7: Induction Motors Why is this so? A V three-phase six-pole Hz induction motor is running at a slip of 3. Answer the questions in Problem for a V three-phase four-pole Hz induction motor running at a slip of 0. A kW V Hz two-pole induction motor has a slip of 6 percent when operating at full-load conditions.

At full-load conditions, the friction and windage losses are W, and the core losses are W. Calculate the slip and the electrical frequency of the rotor at no-load and full-load conditions. What is the speed regulation of this motor [Equation ]? A V four-pole Hz Y-connected wound-rotor induction motor is rated at 15 hp. The power consumed by the Thevenin equivalent circuit must be the same as the power consumed by the original circuit.

For the motor in Problem , what is the slip at the pullout torque? What is the pullout torque of this motor? SOLUTION The slip at pullout torque is found by calculating the Thevenin equivalent of the input circuit from the rotor back to the power supply, and then using that with the rotor circuit model. For the motor of Problem , how much additional resistance referred to the stator circuit would it be necessary to add to the rotor circuit to make the maximum torque occur at starting conditions when the shaft is not moving?

Plot the torque-speed characteristic of this motor with the additional resistance inserted. If the motor in Problem is to be operated on a Hz power system, what must be done to its supply voltage? What will the equivalent circuit component values be at 50 Hz?

Answer the questions in Problem for operation at 50 Hz with a slip of 0. The phase voltage is Figure a shows a simple circuit consisting of a voltage source, a resistor, and two reactances. Find the Thevenin equivalent voltage and impedance of this circuit at the terminals. Figure P shows a simple circuit consisting of a voltage source, two resistors, and two reactances in series with each other.

If the resistor RL is allowed to vary but all the other components are constant, at what value of RL will the maximum possible power be supplied to it? Prove your answer. Use this result to derive the expression for the pullout torque [Equation ]. Gojko Joksimovic. A short summary of this paper. Modelling and analysis of series-connected wound rotor induction motor.

Multiple coupled circuit model is derived and C numerical simulation is provided. Results of numerical simulation confirm existence of electromagnetic torque at both speeds. Stator Rotor Figure 1. Winding connection I.

The reason is probably due to the Resistance matrix is diagonal matrix with elements which are believing that this machine has no inherent starting capability. Machine with series-connected stator and rotor windings Matrix of inductances [L1] is matrix of constant coefficients exhibits an additional behaviour.

Machine with this connection assuming linear magnetic circuit and cylindrical geometry of could works as a synchronous machine at a double induction machine. This matrix is sum of two matrices: matrix synchronous speed.

However, to make it possible, rotor must of self and mutual inductances of stator windings [Lss] and be accelerated by additional means to near this speed before matrix of self and mutual inductances of rotor windings [Lrr]: machine is connected to the grid, [1].

This, till now, unknown fact inductances between rotor and stator windings [Lrs]. This approach is based on is, linear magnetic circuit assumptions. Indices 1 respectively. In above expression r is mean air gap radius, l is or 2 pointed out to stator or rotor respectively. Using transformation of variables, Expression for electromagnetic torque could be obtained through energy of electromagnetic field.

This electromagnetic torque stator current sheet wave and rotor magnetic flux density wave. Stator current sheet wave a1 is, B. The same is true for interaction of stator current sheet of slip Solution of expression 21 is: frequency and rotor magnetic flux density wave of base frequency.

Then, induction motor. As it is clear from this figure, all of the MMF space harmonics from stator as well as from rotor side are taken into account simultaneously, using winding function method. Electromagnetic torque due to the currents of different Rotor speed and developed electromagnetic torque during frequencies start up transient regime is shown on Figures 3 and 4. It is obvious that starting torque is small and with high pulsating Stator current sheet due to the base frequency current is: component as it is predicted by This high torque component is also predicted from analytical Rotor flux density wave due to the slip frequency current, in considerations,