*4.3.1. Variables*

196 Induction Motors – Modelling and Control

**Step (5): Optimization** 

optimization method.

specifications are:

**4.2. Design specifications** 

 Rated power: P [kW] = 30. Line supply voltage: V [V] = 440. Supply frequency: f [Hz] = 50.

Rotor type (squirrel cage or sling-ring): squirrel cage.

Environment conditions: standard (no derating).

Configuration (vertical or horizontal shaft etc.): horizontal shaft.

 Number of phases: 3. Phase connections: delta.

 Insulation class: F; Temperature rise: class B. Protection degree: IP55 – IC411.

NEMA class: B.

**4.3. Problem formulation** 

Efficiency (EFF) =

Starting Torque (Tst) = �Isc

Temperature Rise (Tr) = 0.03 ×

where: Isc is the short circuit current and Ir is the equivalent rotor current.

kW

Slip at Full Load (SFL) = Total Rotor copper loss × Rotor Input × 100 (31)

Total Stator Losses

Ir � �

kg/kW <sup>=</sup> Total Weight

we move to step (5) otherwise step (4) is restarted with new values of parameters.

At the end of step (4) an automatic check is performed. If the design constraints are satisfied

In this step the motor's performances are checked and if found unsatisfactory, the process is restarted in step (4) with new values of parameters. The decision is made based on the PSO

Design calculations are done for a given rating of an induction motor. Standard design

A very important problem in the induction motor design is to select the independent variables otherwise the problem would have been very much complicated using too many

KW + Total Losses (30)

× Slip at Full Load (32)

Total Cooling Area (33)

kW (34)

The variables considered are given in Table 5.


**Table 5.** Design optimization parameters with their domains.
