The experiments are carried out using machines of industrial manufacture. All the test machines are equipped with a special base for attachment to the Machine test system 0.3. The system allows the characteristics of the machines under test to be recorded. Power for the machines under test is provided either directly from the mains or via special laboratory power supplies.
Objectives
- Protective measures and electrical safety
- Setting up electrical machines and putting them into operation
- Use of starting circuits
- Assessment of electrical machine characteristics
Induction or asynchronous machines are in widespread use. In particular, the low-maintenance squirrel cage motors fed via frequency converters are increasingly replacing both DC and AC machines. Asynchronous machines are used as motors and generators for low power applications of up to 2.5 MW. When used as generators in wind turbines, asynchronous generators operate without additional auxiliary energy.
Features
- In order to protect against overheating, the stator windings of the test machines are equipped with temperature sensors
- Should overheating occur, the machine testing system automatically shuts down the machine under test, thus preventing any damage to it.
- The test machines are equipped with an educationally designed terminal board with the winding configuration printed on it.
- The ends of all the windings are connected to the terminal board and can be accessed via 4-mm safety sockets.
- Computer-supported acquisition of measurement data provides for meaningful measurement results.
The individual equipment set is equally suitable for student experiments in laboratories with low voltage supplies (400 V three-phase) and for setting up on a mobile trolley for demonstration by teachers in a classroom. The procedures for the experiments are provided in a printed manual.
The target group is made up of commercial apprentices and students of electrical machine construction. The course offers experiments at an intermediate level and also allows for the necessary insight into machine behaviour for scientific interpretation at undergraduate level.
Topics
- Design and function
- Characteristics on motor operation
- Starting
- Star-delta starting
- Stator resistance starting circuit
- Braking
- Power performance of an ideal rotating field machine
- Power flux
- Open-circuit experiment
- Short-circuit load experiment
- Fundamentals of three-phase generators
- Characteristics in generator operation
- Generator slip
- Self-excitation of an asynchronous generator
- Voltage stability
- Operation in a constant-voltage, constant frequency system
- Insular operation
- Power performance
Main components:
Equipment for basic experiments
