ELECTRICAL DRIVES POWER ELECTRONICS

Line-commutated converters

E2.4.2.2

With this equipment, the operating behaviour of a phase-angle control can be taught and troubleshooting can be systematically trained on the basis of 20 adjustable faults without endangering components or persons.

The fault simulator is a standard dimmer for a resistive load (Pmax. = 1.2 kW) pre-calibrated for minimum value. Various measuring points allow for systematic troubleshooting. There are a total of 20 faults which can be switched and which are of the following categories:

Breaks

Shor t-circuits

Wrong components

Component faults

The faults are activated by slider switches located behind a lockable cover.

* additionally recommended* additionally recommended

The pictured experiment stand is not included in this equipment. It can be added on request for an extra charge.

Self-commutated converters

E2.4.3.1

Switchable valves and DC controllers

This equipment is equipped with DC choppers and deals with the valves that can be used for this purpose. DC choppers convert direct current of a given voltage and polarity into direct current of a different voltage and/or polarity. In contrast to other methods of voltage adjustment, they operate in principle without loss, practically with high efficiency, since the electronic valves are used in periodic switching operation. Today, DC choppers are used in a wide range of voltage, current and power applications, from power supply units for electronic circuits to the supply of trams, light railways and underground railways from DC networks.

Static converter valves with gate turn-off can be used to assemble a variety of DC controllers (DC/DC converters). Three different control methods are used for this:

Pulse width modulation

Pulse sequence modulation

Two position control

Electrical Drives Power Electronics

Self-commutated converters

Switched-mode power supplies (E2.4.3.2)

The pictured experiment stand is not included in this equipment. It can be added on request for an extra charge.

Power electronics enables the construction of power supplies that are characterised by high efficiency and small size. This is achieved with switching components and at the highest possible switching frequencies. The following experiments on primary switched-mode power supplies can be set up and examined with regard to their properties:

Buck converter

With different loads, Control of the voltage and current average by means of pulse width modulation, Function of a free-wheeling diode with ohmic inductive load, Function of a smoothing capacitor with ohmic inductive load, Efficiency of the buck converter

Inverting boost and buck converter

With different loads, Control of the voltage and current average using pulse width modulation, Function of choke with gap current

The pictured experiment stand is not included in this equipment. It can be added on request for an extra charge.

Electrical Drives

Self-commutated converters

E2.4.3.3 Flyback converters, flow converters and inverters

Primary switched-mode power supplies have a converter, there are two different converter principles: of the voltage and current average reversal Generation of a frequency and amplitude variable alternating voltage

E2.5.4.3

Starting of large flywheel masses with slip ring motor

For more information, see page 69.