AC auto-transformer, 0.3

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 a power analyser as a measuring device
• Fundamental circuits of the transformers

Auto-transformers are designed to save on materials. They are distinct from conventional transformers in that they have a common winding for the primary and secondary circuits which is tapped part way along. Auto-transformers therefore do not have any galvanic isolation between the primary and secondary. The auto-transformer has a complex equivalent circuit and can only be described to a limited extent by short-circuit, no-load and load tests.

Highlights:

The measurements are carried out with a power analyser.

All functions of the Power Analyser CASSY can be operated quickly and directly via the display, the rotary wheel and the buttons on the unit. All settings and measurement results can be saved on the unit and quickly called up again later or simply downloaded.

In addition, the Power Analyser CASSY is fully controllable in real time via RJ45 Ethernet, W-LAN and USB-C interfaces.

These interfaces can be used by the following software:

• CASSY Lab 2 for drives and energy systems,
• MATLAB® and LabVIEW ™
• Lab Docs Editor Advanced

The following integrated servers are available in the Power Analyser CASSY for the local media connection of at least four end devices simultaneously.

For more details, see product data 727110 or 727111 Power Analyser CASSY.

The individual equipment is equally suitable for student experiments in the laboratory with low voltage (230 / 400 V three-phase current) and - with a mobile trainer - for teacher demonstration in the classroom. The experiments are carried out according to the 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. The media connection makes the experiments suitable for demonstration in the classroom or a lecture hall.

In the following configurations there are further extended experiments with transformers:

• E2.3.1.1 Three-phase transformer
• E2.3.1.2 Scott transformer
• E2.3.1.3 AC transformer
• E2.3.1.4 AC auto-transformer

Topics

• Voltage equation and equivalent circuit
• Losses, changes in voltage and efficiency