A Bit-Stream modulator for a 3-state full bridge inverter

Abstract

Bit-Stream based control, which uses one bit wide signals to control power electronics applications, is a new approach for controller design. Bit-Stream signals can be directly applied to control electronic devices but the high speed nature of Bit-Stream signals can lead to excessive switching losses. Thus it is essential to down-sample Bit-Stream signals to reduce switching losses to acceptable levels. This paper presents a novel modulator, which down-samples high frequency Bit-Streams to low frequency switching signals that are suitable for driving a three-state full-bridge inverter. Methods for compensating for switch dead time and balancing switching losses of the inverter legs are presented, and the performance of the proposed modulator is compared to a standard PWM strategy to show that it produces output currents with comparable THD and reduced switching losses.