Each one of the circuits is explained below. These sections are Rectifier Section, DC Bus / Filter Section, Inverter Section and Control Unit Section. Simply put it converts the AC into DC and then into AC having adjustable frequency but the operation uses four blocks or sections of VFD. The main function of a VFD is to vary the operating frequency of an AC supply. The block diagram of a VFD is also given below.Įach block is explained in detail down below. The four blocks or sections of a VFD are Rectifier, DC bus/filter, Inverter and Control Unit. Generally, a VFD is made of four blocks or sections where each section has its own function. Related Post: Difference Between Soft Starter & VFD (Variable Frequency Drive).Due to its programmable and easy to use UI (user interface), it can be easily used to monitor and maintain the speed of an electrical motor. It even enables a motor to run above its rated speed by increasing the frequency. Since the speed of an induction motor depends on the supply frequency, the VFD can be used to vary its speed.Ī VFD is a power converter that uses electronic circuits to convert a fixed frequency and fixed voltage into a variable frequency and variable voltage. As its name suggests it is an adjustable frequency drive that varies the frequency of the AC supply.
