Let’s say, ‘s’ is the slip of the running motor. Cited formula below represents the value of Torque when it acts on the rotor:

At the standstill position in rotor with induced electromotive force (e.m.f), the value of torque with

Considering k’ is added constant

With the statement that slip ‘s’ is very low at full load condition, it will be okay to state that S2X2 will be neglected as compared to R22, therefore value of torque will be:

  sV²

The torque changes even on the running condition as the supply voltage is altered or changed. Let’s consider both the conditions:

• When supply voltage is decreased, torque is also reduced under running condition
• With increase in supply voltage, torque is also greater than before

But it is important to maintain the same torque in running condition which is possible when the slip increases or the speed decreases.

• Current Electricity Basic Concepts
• Introduction to Alternating Current
• Introduction Three Phase A C Circuits
• Magnetic Field
• General Aspects
• General Aspects Polyphase Induction Motors
• Classification of A C Motors
• Constructional Details
• Production of Rotating Magnetic Field
• Theory of Operation of an Induction Motor
• Slip
• Frequency of Rotor Current
• Rotor E M F and Rotor Current

Links of Next Electrical Engineering Topics:-

• Torque Slip and Torque Speed Curves
• Operating Characteristics 3 Phase Squirrel Cage Induction Motor
• Shows a Wound Rotor Induction Motor with Controller Rheostat
• Power Stages in an Induction Motor
• Induction Motor as Transformer
• Equivalent Circuit of an Induction Motor
• Starting of Induction Motors
• Factors Governing Performance of Induction Motors
• Effects of Operating Conditions
• Ratings of 3 Phase Induction Motors
• Squirrel Cage Motors Advantages Disadvantages and Applications
• Wound Rotor or Slip Ring Induction Motors Advantages Disadvantages and Applications
• Comparison of a Squirrel Cage and a Slip Ring or Phase Wound
• Comparison Induction Synchronous Motors
• Highlights in Polyphase Induction Motors
• Single Phase Motors
• Characteristics of D C Generators
• Measuring Instruments
• Power Supply System

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