PSL50 - Experiment


For use with a selection of interchangeable relays units to allow students to investigate the theory and practice of electrical power system protection.

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A test set that gives students theoretical and practical experience with a variety of industrial relays. The equipment uses industrial protection equipment and techniques, and a range of industrial relays, adapted for educational use.

The test set allows students to compare individual relay characteristics. It also allows connection of two relays for experiments such as relay discrimination.
The test set includes meters, current and voltage transformers (CTs and VTs), power supplies, a configurable transformer and load resistors. It also has a useful desk space for students to work on.

The configurable transformer has a star connected primary, but the secondary has multiple tappings. So, the user may connect it as delta or star with different voltage ratios. Controls on the lower panel of the test set allow the user to adjust the test voltage supply, current and load resistances.

A transmission line on the upper panel of the test set allows students to set up distance protection and parallel feeder tests.

TecQuipment supply each relay in rugged, portable enclosures. The relays rest on the desktop either end of the test set. The user programs the relays either directly or using software. The test set includes relay support software which enables users to program the relay modules using a suitable computer.

Students connect the relays to the test circuits on the front of the test set. A multi-core cable connects from the back of the test set to the back of each relay to give it a supply current for correct operation. The test set has clear schematic diagrams to help students carry out and understand the experiments.

Learning outcomes

  • Overcurrent protection
  • Relay discrimination using current and time settings
  • Directional protection
  • Differential protection
  • Earth fault protection
  • Distance protection
  • Current Transformer (CT) polarity
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