Головна |
1. What currents set up a changing magnetic field which rotates around the inside of the stator?
2. What is a synchronous speed?
3. What is the rotating field produced by in the simplest type of 3-phase induction motor?
4. How many rotations for every cycle of the supply voltage does the flux perform when the three stator windings are connected to the 3-phase power supply?
5. What is a 2 pole motor?
6. Where is a magnetic field induced in a normal induction motor?
7. What must be present across the rotor bars to establish a current flow in the rotor?
8. What speed must the rotor rotate at to produce torque?
9. What is a slip?
10. What is a slip speed?
11. What is the amount of slip determined by?
12. What does the direction of the rotating stator flux depend on?
13. What is a phase sequence?
VII. Define the functions of Participle I and Participle II in the following sentences
1. When the induction motor is supplied from a power source of constant voltage and frequency, the current drawn by the motor depends primarily on the slip.
2. At no-load, the motor will draw only no-load magnetizing current.
3. When matching motors to mechanical loads, the two most important considerations are torque and speed.
4. Induced voltage reappears in the rotor, but in the opposite direction.
5. When set up a changing magnetic field rotates around the inside of the stator.
II. Memorize the words and word combinations and their equivalents. | Simple Two Pole DC Motor Rotation | II. Read and translate the text. | I. Read and memorise the words and word combinations. | III. Read and translate the text. | III. Read and translate the text | VII. Answer the questions to the text. | III. Read and translate the text. | III.Read and translate the text. | VII. Answer the questions. |