|Electrical Machines - Basic vocational knowledge (Institut für Berufliche Entwicklung, 144 p.)|
|4. Synchronous machines|
|4.4. Use of synchronous machines|
Synchronous motors are used to drive pumps and compressors above all in the chemical industry and as drives for rotating tubular furnaces. There is also a combined application of bigger synchronous machines as motor and generator in pump storage plants. The synchronous machine is coupled to a water tube and a pump. Due to low network loads it operates as a motor and pumps water into a raised basin. During peak network load spells this water is able to run back into the lower basin by means of a turbine. The synchronous machine then operates as a generator.
Questions for repetition and control
1. Given a speed of n = 60 rpm, a synchronous generator shall generate an alternating voltage at a frequency of f = 50 Hz. How many pole pairs are required?
2. What is the operating frequency of a synchronous machine with two pole pairs where the rotor evidences a speed of 1500 rpm?
3. How can the voltage of a synchronous motor be changed?
4. Which conditions must be heeded for parallel switching of synchronous generators?