Valve control and DC to DC convert

Description

The experiments are carried out on training panels in panel frames.

Objectives

• Protective measures and electrical safety
• Circuit assembly and wiring according to circuit diagrams
• Use of commercial measuring instruments: hand-held multimeters and oscilloscopes

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

• Pulse width modulation
• Pulse sequence modulation
• Two position control

The equipment set is suitable both for student experiments in a lab using low voltage (400 V three-phase) and on a mobile trolley for demonstrations by teachers in a classroom. The experiment procedures are contained in a printed 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.

Topics

• Thyristor with quenching circuit
• Power MOSFETs
• Insulated gate bipolar transistors (IGBTs)
• On-state characteristics
• Off-state and switching properties
• Control of DC choppers
• Step-up and step-down converters
• DC choppers using a thyristor with quenching circuit, PWM
• Control characteristic for constant load current
• DC chopper using MOSFETs, PWM, PFM and two-position control
• Single-ended forward and push-pull converters
• Half-bridge and full-bridge forward converters
• DC choppers used for step-up conversion, PWM and two-position control
• Energy recovery operation with PWM
• Energy recovery operation with two-position control
• Characteristics with variable current setpoints
• DC choppers with IGBT used as inverting step-up/step-down controllers with PWM