Asynchronous motor P2 = 45 kW; h = 200 mm

Contents

1. Design Input

2. Introduction

3.Magnetic circuit of the engine

3.1Selection of main dimensions

3.2 Stator core

3.3 Rotor core

4. Winding the stator

5. Winding of short-circuited rotor

Short-circuiting ring of rotor winding

6. Magnetic circuit calculation

6.1 MDS for air clearance

6.2 MDS for teeth at trapezoidal semi-closed slots of stator

6.3MDS for teeth with oval closed rotor slots

6.4 MDS for stator back

6.5 MDS for rotor back

6.6 Magnetic Circuit Parameters

7. Active and inductive resistance of windings

7.1 Stator winding resistance

7.2 Resistance of short-circuited rotor winding with oval closed slots

7.3 Resistance of windings of converted motor replacement circuit (with magnetizing circuit placed on clamps)

8. Calculation of idle and nominal modes

8.1 Calculation of mode x. x

8.2 Calculation of nominal operation mode parameters

9. Performance calculation

10. Maximum moment

11. Initial starting current and initial starting moment

12. Thermal calculation of asynchronous motor

12.1 Stator winding

12.2 Ventilation calculation

13. Engine weight and dynamic moment of rotor inertia

14. Conclusion

15. List of literature

Summary

The course project contains 44 sheets, 1 table, 4 sources used.

The calculation of asynchronous motor with short-circuited rotor of series 4A 71 S1 U3 with capacity of 45 kV is given, which includes:

-selection of main dimensions

-electromagnetic calculation

- calculation and construction of operating and start-up characteristics

- simplified thermal and ventilation calculations.

Asynchronous motor assembly drawing and rotor assembly drawing are given.

Design Input

Nominal operating mode......................... Extended (S1)

Height of rotation axis h, mm......................................................... 200

Rotor design....................................... Short-circuited

Rated output power P2, kW.................................. 45

Number of stator phases m......................................................... 3

Method of connection of stator phases..................................................................................... Δ/Y

Network frequency f, Hz...................................................................... 50

Nominal line voltage U, V.............................. 220/380

Synchronous speed n1, rpm................................. 1500

Degree of protection against external influences.............................................................................................................................

Cooling method.........................................................................................................................................................................................

Installation Method Design ...................................................................................................................................................................................................................................................................................................................................................................................................................................................................IMIMIM1IM

Climatic conditions and accommodation category..................................... U3

Shape of projecting shaft end............................ Cylindrical

Method of connection with drive mechanism.............. Elastic coupling

Number of pairs of poles p......................................................... 2

Introduction

An asynchronous motor is an AC electric motor whose rotor speed is not equal (in motor mode less) to the rotation frequency of the magnetic field created by the current of the stator winding.

Currently, asynchronous motors consume more than 40% of the generated electric energy, a large number of scarce materials are used for their manufacture: winding copper, insulation, electric steel and other costs.

Therefore, the creation of a series of highly economical and reliable asynchronous motors is the most important national economic task, and the correct choice of engines, their operation and high-quality repair play a primary role in saving materials and labor resources.

In the 4A series, due to the use of new electrical materials of an irrational design, the engine power at these heights of the rotation axis is increased by 2-3 stages compared to the power of the A2 series engines, which gives a large saving of scarce materials.

Conclusion

In this course project, an asynchronous motor with a short-circuited rotor was designed. As a result of the calculation, the main indicators for the engine were obtained.

Almost all the basic parameters of these sections are in

intervals that were specified in the used literature for

performing this course work.

On the basis of the obtained results, assembly drawings of the asynchronous motor and rotor were built.