ABSTRACT
Multiple-quadrant operation converters can be derived from the multiplequadrant chopper. Correspondingly, class B converters can be derived from type B choppers (two-quadrant operation), class E converters from type E choppers (four-quadrant operation) and so on. Also, multiple-quadrant operation converters can be derived from other first generation converters. This chapter introduces two-and four-quadrant operation Luo-converters, which are derived from positive, negative and double output Luo-converters. They correspond to a DC motor drive in forward and reverse running with motoring and regenerative braking states. These converters are shown in Figure 1.1. The input source and output load are usually certain voltages as shown V1 and V2. Switches S1 and S2 in this diagram are power MOSFET devices, and driven by a pulse-width-modulated (PWM) switching signal with repeating frequency f and conduction duty k. In this chapter the switch repeating period is T = 1/f, the switch-on period is kT and switch-off period is (1 – k)T. The equivalent resistance is R for each inductor. During switchon the voltage drop across the switches and diodes are VS and VD. When the switch is turned off, the free-wheeling diode current descends in whole switch-off period (1 – k)T. If the diode current does not become zero before
the switch is turned on again, we define this working state to be the continuous region. If the current becomes zero before the switch is turned on again, this working state is the discontinuous conduction region.
