Final answer:
The three additional main sections of a VFD are the Rectifier Section, the DC Bus Section, and the Inverter Section. The purpose of the Rectifier Section is to convert AC power into DC power, while the DC Bus Section stores and distributes the DC power. The Inverter Section converts the DC power back into AC power at the desired frequency and voltage.
Step-by-step explanation:
Controller Section:
The controller section of a VFD is responsible for receiving and processing signals from the user interface and converting them into appropriate commands for the other sections of the device.
Rectifier Section:
The rectifier section is tasked with converting AC power from the input source into DC power. It typically consists of a bridge rectifier that employs diodes to achieve the conversion.
DC Bus Section:
The DC bus section acts as an energy storage and distribution system. It contains a capacitor that smooths and stores the DC power received from the rectifier section, providing a stable voltage for the inverter section.
Inverter Section:
The inverter section takes the DC power from the DC bus section and converts it back into AC power at the desired frequency and voltage. This section typically uses insulated gate bipolar transistors (IGBTs) to control the output waveform.