construction and working of four quadrant chopper

construction and working of four quadrant chopper pdf

Abstract

In chopper circuits, unidirectional power semiconductors are used. If these semiconductor devices are arranged appropriately, a chopper can work in any of the four quadrants. we can classify chopper circuits according to their working in any of these four quadrants as type A, type B, type C, type D and type E. Let us now take a look of these classifications and the characteristics of various classifications.

Type A Chopper or First–Quadrant Chopper

This type of chopper is shown in the figure. It is known as first-quadrant chopper or type A chopper. When the chopper is on, v0 = VS as a result and the current flows in the direction of the load. But when the chopper is off v0 is zero but I0 continues to flow in the same direction through the freewheeling diode FD, thus average value of voltage and current say V0 and I0 will be always positive as shown in the graph.