IT-620 Electrical Power Transmission Trainer

AC electrical power is generated in power stations, usually far from end users. This power is then transported over long distances using high voltage and low loss transmission lines. High voltage is achieved by using step up transformers and is fed to the transmission lines. Similarly, at user end, step down transformers are used to provide power to the users. This is possible only by using transformers. Transformers are used for stepping up the voltage of the generator to values which are suitable for high voltage systems, for power exchanging between networks, for stepping down the voltages to the medium voltage level and then for feeding the power into the low voltage network. In this laboratory a three-phase transformer is investigated. It consists of three individual poles with different connection possibilities on the primary side and variable secondary voltage. Power transmission lines are used to transmit electrical energy from the power stations to the consumers.

Description

AC electrical power is generated in power stations, usually far from end users. This power is then transported over long distances using high voltage and low loss transmission lines. High voltage is achieved by using step up transformers and is fed to the transmission lines. Similarly, at user end, step down transformers are used to provide power to the users. This is possible only by using transformers. Transformers are used for stepping up the voltage of the generator to values which are suitable for high voltage systems, for power exchanging between networks, for stepping down the voltages to the medium voltage level and then for feeding the power into the low voltage network. In this laboratory a three-phase transformer is investigated. It consists of three individual poles with different connection possibilities on the primary side and variable secondary voltage. Power transmission lines are used to transmit electrical energy from the power stations to the consumers.

Advantage of three-phase systems is that it provides the consumers with two different levels of voltage, so that they can use their equipment in the best possible way. A three-phase model of an overhead power transmission line (with a simulated length of 360 km long, a simulated voltage of 380 kV and a simulated current of 1000 A) is used, with a scale factor of 1:1000.

Transmission line characteristics are investigated under various load conditions. Circuit configurations are then connected for the demonstration of various neutral point connections in three-phase mains systems. Different voltage levels are used for transmitting power; the levels are determined by the amount of power and the distance; the higher the transmission voltages, the lower the currents as well as the transmission losses. However the network investment cost increases with the voltage.

Asymmetrical short-circuits are also simulated. Other topics covered by this laboratory are reactive power compensation, the basic circuits of power engineering, series and parallel connections of operating equipment (lines, transformers), circuit involving the conversion of delta connections to star connections, circuit involving the conversion of star connections to delta connections, busbars, disconnectors, power circuit breakers, voltage and current transformers.

 

Features:

Module Based

Power Supplies Included

Flexibility to Perform Custom Experiments

Passive Components Included

Resistors, Capacitors and Inductors Included

Control Circuits Included

P.T. and other Passive Components Included

Protection Circuits Included

 

Description Module 620 Transmission
Variable three-phase power supply IT-6000

1

Line model IT-6002

2

Three-phase transformer IT-6003

1

Resistive load IT-6004

1

Inductive load IT-6005

1

Capacitive load IT-6006

1

Three-phase power supply IT-6017

1

Power circuit breaker IT-6019

4

Double busbar with two disconnectors IT-6020-2

1

Double busbar with four disconnectors IT-6020-4

1

Line capacitor IT-6021

2

Petersen coil IT-6022

1

Moving coil ammeter 0-1000mA IT-6034

1

Moving coil ammeter (1.25-205A) IT-6035

3

Moving iron voltmeter (600V) IT-6037

2

Moving iron voltmeter IT-6038

3

Power meter IT-6048

2

Power factor meter IT-6049

1

Base Frame IT-2L

1

Leads (Accessory) IT-ACC

1 set

 

 

Experiments Included:

Three-Phase Transformer

Determination of the vector group of the three-phase transformer

Determination of the voltage transformation ratio of the transformer operating at no-load

Determination of the current transformation ratio of the transformer operating with short-circuit

Determination of the equivalent circuit quantities based on the consumed active and reactive power

Measurement of the effect of the load type and magnitude on the performance of the secondary voltage

Determination of the efficiency of the transformer

Investigation of the zero-impedance of the three-phase transformer with various connection modes

Examination of the load capacity of the secondary side using a single-phase load with different connection modes on the primary side

Determination of the influence of a delta stabilizing winding

Demonstration of the possibility of utilizing a three-phase transformer in economy connection (autotransformer)

 

Overhead Line Model

Measurement of the voltage in no-load operation

Concept of operating capacitance

Line model with increased operating capacitance

Measurement of current and voltage relationship of an overhead line in matched-load operation, interpretation of the terms: characteristic wave impedance, lagging and leading operation, efficiency and transmission losses

Measurement and interpretation of the current and voltage ratios of a transmission line during a three-phase short-circuit

Measurement and interpretation of the current and voltage ratios of a transmission line with mixed ohmic-inductive and pure inductive loads

Measurement and interpretation of the current and voltage ratios of a transmission line with mixed ohmic-capacitive and pure capacitive loads

Investigation on the performance of a transmission line with isolated neutral point connection in the case of a fault to earth

Measurement of the earth-fault current and the voltage rise of the fault phases

Determination of the inductance of an earth-fault neutralizer for the overhead line model

Investigation on the performance of a transmission line with a fault and comparison of the current values with those determined during earth-fault with isolated neutral point system

Measurement of the fault currents of the results with those for a three-phase fault

Investigation on the effect of parallel compensation on the voltage stability at the load and the transmission losses of the line

Investigation on the effect of series compensation on the voltage stability at the load

Use of measurement techniques to determine the zero-phase sequence impedance of the overhead line model and comparison of this value with the theoretical one

 

Alternator and Parallel Operation

Measurement of the voltage distribution in the series connection of two lines without operating capacitance

Measurement of the voltage distribution in the series connection of two lines with operating capacitances

Measurement of the voltage distribution in the parallel connection of two lines without operating capacitances

Measurement of the voltage distribution in the parallel connection of two lines with operating capacitance

 

Busbar System

Operation of a switching station with two bushars and different voltage

Busbar transfer with interruption of the power supply to the consumer

Busbar coupling and bus transfer without interruption of the power supply to the consumer

Switching sequence for disconnectors and power circuit breakers