Power System Trainer school teaching equipment Electrical Skills Training Equipment

ZE8552 Power System Trainer school teaching equipment Electrical Skills Training

Power System Trainer (PSS1): A self-contained unit that simulates all parts of electrical power systems and their protection, from generation to utilization

Key Features

Simulates generation, transmission, transformation, distribution, utilization and protection in one self-contained unit

Includes prime mover and generator to simulate power generation

Twin distribution transformers for parallel transformer and load flow tests

Includes industrial-standard digital protection relays for realistic training

Key Specifications

Prime mover and generator

Eleven protection relays

Twin distribution transformers

Switched busbar with six feeders

Seven transmission lines

Two distribution loads

Two utilization loads

• One dynamic load

Description

The Power System Trainer contains everything needed to teach students how electrical power systems work. It is a self-contained unit (only needs electrical power) with full safety features. It includes all the main parts of an electrical power system, from supply (generation) to demand (utilization). Each part includes dedicated industrial-standard protection relays that do specific jobs, from generator protection to distance protection on transmission lines, and distribution transformer protection.

Generator and grid supply

The Power system trainer has a motor (prime mover) and generator set to simulate power generation. This set has characteristics similar to industrial turbine and generator sets for realistic experiments. The output of the generator passes through a generator transformer to a ‘generator bus’. Protection relays and circuit-breakers monitor and switch the generator field and output. The Power system trainer includes a fully monitored and protected grid supply transformer. This transformer simulates the larger grid transformers used in national grid supply systems. The grid transformer reduces the incoming mains supply to give the correct distribution voltage at the ‘grid bus’. It also allows students to correctly synchronize the generator output to the grid supply. For realistic tests, students can use the grid supply or the generator as a power source for their experiments.

Transmission lines

A set of reactances simulate transmission lines of different lengths to model the characteristics of overhead or underground power cables. Each line includes test points to monitor the conditions along the lines. The user can simulate faults at different places along the transmission lines and discover the effects. A dedicated distance protection relay protects the lines and can indicate how far along the line the fault has occurred.

Transformation, distribution and utilization

As well as the grid supply and generator transformers, the Power System Trainer has two identical distribution transformers to simulate the distribution transformers fitted near to factories or houses. These transformers have variable tapping and feed a ‘utilization bus’. Dedicated relays protect the transformers and can work in different ways, determined by student experiments. The utilization bus simulates electrical consumers (houses and factories). It includes variable resistive, capacitive and inductive loads, with an induction motor (dynamic) load. A switched busbar section includes a main bus and a standby or ‘reserve bus’. These simulate a real bus switching system in a power plant or power distribution station. Protection relays and circuit-breakers monitor and switch the incoming and outgoing feeders of the busbar. One feeder of the busbar has a ‘point-on-wave’ circuit breaker for studies of switching transients.

Detailed Specifications

1. a) Voltages:

Distribution: 415 V three-phase line to line

Utilization: 415 V three-phase line to line

Grid transformer:

5 kVA delta to star (Dy11)

Primary is matched to the incoming three-phase supply to give the 220 V three-phase line-to-line secondary distribution voltage. Includes earth link for the secondary star point and a selectable tapping earth resistor for restricted earth fault protection tests.

Generator and prime mover:

6 kVA maximum (operated at a nominal 2 kVA), four pole salient pole a.c generator Brushless, with automatic and manual excitation.

7 kVA maximum induction motor with shaft encoder and electronic four-quadrant a.c vector-drive control, with a four-position drive inertia switch

Generator transformer:

1:1 ratio delta-to-star (Dy11) impedance matching with adjustable secondary tapping

Transmission lines:

 Line reactances simulate ‘per unit’ (pu) values of impedance:

Line 1: 0.10 pu

Lines 2 and 3: 0.15 pu

Lines 4 and 5: 0.25 pu

Line 6: 5 x 0.1 pu length with four test points and dedicated three-zone distance protection

Line 7: 4 x 0.01 pu (cable)

Capacitors are provided adjacent to the lines. Each capacitor has selectable values and may be inserted in circuit to give π or T-line configurations for studies of losses.

Distribution transformers:

Two identical 2 kVA transformers, 415 V to 220 V Star-to-delta Yd1 Adjustable primary tapping and matched impedances

Switched busbar:

Six bi-directional feeders, each with circuit-breakers – one circuit breaker is a ‘point-on-wave’ device

Two circuit-breakers to break each half of each bus

Twelve bus isolators, six on each half of the bus

Two circuit-breakers that break the coupling between the main and reserve bus

Protection relays:

Grid transformer protection

Grid bus protection

Generator protection

Generator bus protection

Distance protection

2 x double bus protection

4 x distribution transformer protection

Loads:

Two separate 415 V (distribution) loads, each with delta-connected variable resistors and inductors; one load is near to the generator and the other near to the distribution bus.

Two sets of 415 V (utilization) loads at the utilization bus; each has delta-connected variable resistors, inductors and capacitor banks.

One dynamic load – an induction motor at the utilization bus

Electrical supply:

Three-phase 10 kW, 50 Hz

Learning Outcomes

Power transmission, distribution and utilization

Load flow, circuit interruption and differential protection

Symmetrical, unsymmetrical and unbalanced faults and loads

Generator synchronization and performance, including stability and voltage regulation and control

Using protection relays for overcurrent, distance protection, phase and earth faults

Using protection relays for differential protection, under and overvoltage and frequency protection

Transformer tapping and impedances

Using relays for protection of a busbar, transformers and generators