Exercices Corrigés Machines à Courant Alternatif Électromécanique des Systèmes Automatisées-ESA-OFPPT-PDF - Électromécanique des systèmes automatisés

# Exercices Corrigés Machines à Courant Alternatif Électromécanique des Systèmes Automatisées-ESA-OFPPT-PDF

### Exercices Corrigés Machines à Courant Alternatif Électromécanique des Systèmes Automatisées-ESA-OFPPT-PDF ### Exercices Corrigés Machines à Courant Alternatif

#### ESA-OFPPT-PDF

Exercices Corrigés Machines à Courant Continu / Alternatif

Data

An asynchronous ring motor has the following characteristics: 95 kW; 230V / 400V; 50 Hz; 8 poles.

1) Knowing that it is powered by a three-phase 400V line, what should be the coupling?

2) Calculate the synchronism frequency.

When running, the slip is worth 4%:

3) Deduce the frequency of rotation.

4) What is then the value of the useful torque.

The motor is very powerful, we can neglect its stator and mechanical losses. For nominal speed:

5) Calculate the electrical power absorbed.

6) Calculate the intensity of the current absorbed by the stator if the power factor is 0.83.

We now supply the motor with a 230 V line.

7) What is the coupling of the stator?

8) Calculate the effective value of the current intensity in the line.

9) Calculate the effective value of the current intensity in a winding.

Answers: 1 / star 2 / 750rpm 3 / 720rpm 4 / 1260Nm 5 / 98958W 6 / 172A 7 / triangle 8 / 298A 9 / 172A.

An asynchronous star-coupled motor carries the following indications 220V / 380V:

No load: Io = 5.2 A Po = 390 W

On load: I = 7.5 A P = 4070 W

The resistance between two phases of the stator was measured hot R = 2.2 W.

Assuming that the mechanical and magnetic losses are equal, calculate the motor efficiency if the frequency

rotation is 1430 rpm.

An asynchronous motor is such that:

When empty, its frequency of rotation is close to synchronism.

In load, its mechanical characteristic is practically straight.

In nominal operation, the following have been determined: Pa = 3.4 kW; Ș = 86.5%; n ’= 1440 rpm

Calculate the synchronism frequency and the number of poles.

1) Calculate the moment of the useful torque.

2) Give the equation of the mechanical characteristic in its useful part.

3) In reduced load operation, the slip is 2.67%.

4) Give the frequency of rotation.

5) Determine the useful torque and the useful power.

6) The resistive torque of the driven machine takes the value of 22 Nm. Calculate the slip.

Answers: 1 / 1500rpm 4 poles 2 / 19.5Nm 3 / Cu = -0.325 n ’+ 487.58 4 / 1460rpm 5 / 13Nm

1432rpm 6/5,  Thanks for reading Exercices Corrigés Machines à Courant Alternatif Électromécanique des Systèmes Automatisées-ESA-OFPPT-PDF

Previous
« Prev Post