Torque speed curve
- 1. Supervised by ……………. Dept. of EEE Bangladesh
- 2. Green University of Bangladesh Presentation on Torque speed curve
- 3. › Torque & Speed › Several important information › Characteristic curve › Plot of speed › Power converted Content
- 4. › The quantitative measure of the tendency of a force to cause or change rotational motion is called torque. › Motors are devices that convert electrical energy into mechanical energy. The D.C. motors that we have been dealing with here convert electrical energy into rotational energy. That rotational energy is then used to lift things, propel things, turn things, etc... When we supply the specified voltage to a motor, it rotates the output shaft at some speed. This rotational speed or angular velocity, is typically measured in radians/second {rad/s}.. Torque & Speed
- 5. Induced torque of motor is zero at syn. Speed Torque-speed curve is nearly linear between no load and full load. In this range rotor resistance is much larger than its reactance so rotor current, rotor magnetic field & induced torque increase linearly with increasing slip There is a maximum possible torque that cannot be exceeded (pullout torque) is 2 to 3 times rated full-load torque of motor (calculated in next section) Starting torque on motor is slightly larger than its full-load torque, so this motor will start carrying any load that it can supply at full power Note: that torque on motor for a given slip varies as square of applied voltage. This is useful in one form of induction motor speed control that will be described Torque-speed characteristics curve provides several important information
- 6. A typical induction motor torque-speed characteristic curve
- 7. A plot of speed above & below normal range shown below
- 8. › Note: peak power supplied by induction motor occurs at a different speed than maximum torque, and of course no power is converted to mechanical form when rotor is at zero speed Power converted to mechanical in an induction motor
- 9. Induced Torque & Power Converted versus motor Speed in r/min (4 pole induction motor)
- 10. Thanks to all