Basics of Frequency Converters

Description

Lidinco provides basic inverter engineering practice sets for laboratory use, practice
This laboratory practical utilises training panels in panel frames. The power is supplied to the frequency converter directly from the mains (mains voltage, 230 V).

Objectives

• Protective measures and electrical safety
• Components of a frequency converter with variable voltage link
• Setting parameters for frequency converters
• Gaining skill in measurement techniques

This equipment set offers an insight into the circuitry of frequency converters with variable voltage link. Measurements are made on the components of a frequency converter especially designed for educational purposes. The experiments use a static electronic load, which facilitates the evaluation of current and voltage curves. A rotating field with variable frequency is also investigated. The following components can be accessed:

• Input bridge rectifier with link capacitor
• Brake chopper
• Power inverter

Students work in the power engineering lab with mains voltage. Experiments procedures are contained in a printed manual.

The experiments are designed for intermediate and advanced levels.

Topics

• Rotating field and space vectors
• Feeding a sinusoidal signal from the normal three-phase mains network
• Representation of space vectors
• Generation of a rotating field from a DC voltage
• Putting a converter into operation
• Fault-free activation of the mains voltage
• Activation of the input rectifier
• Switching off the converter
• Discharging the buffer capacitor
• Investigation of input rectifier
• Response with zero-delay angle setting, Cl = 00
• Control characteristic
• Loading
• Control via external control voltage
• Investigation of output inverter
• Control of individual power transistors
• Generation of rotating field
• Loading with resistive load