300W transformers

Description

The experiments are carried out using transformers on training panels in panel frames.

Objectives

• Protective measures and electrical safety
• Set-up of power generation systems according to circuit diagrams
• Use of commercial measuring instruments, hand-held multimeters, oscilloscopes, measuring interfaces

Transformers are magnetically coupled systems used for transforming AC voltages or matching impedance. Transformers can therefore be used primarily for measurement or generation of electric power. These practical exercises study exclusively transformers used in energy generation. Transformer power ratings can range from a few mVA up to several MVA. The size and design also have an important effect on the transformer ratings. Transformers are regarded as electrical machines even though they contain no moving parts. The windings of three-phase transformers can be connected in a variety of circuit configurations.

Students carry out the experiments as specified in the printed manual. Hand-held multimeters are used to measure the characteristics of the transformers. Display of current or voltage against time is particularly interesting for three-phase equipment, although it is not essential. If this aspect is not required, then it is possible to dispense with the oscilloscope, isolating amplifier etc. or Sensor-CASSY. In this case multimeters are sufficient for measuring RMS values.

The target group is made up of commercial apprentices and students of power engineering. The course offers experiments at an intermediate level for vocational colleges and undergraduate level.

The complete equipment set allows for experiments on all the most important types of transformer in the 300 W rating class.

Topics

• Voltage equation and equivalent circuit
• Measurement without load, with load and with a short circuit
• Determination of self-inductance, magnetic coupling and leakage
• Losses, changes in voltage and efficiency