Half load-cycle one-cycle control for inverter

Abstract

The conventional one-cycle control (OCC) technique requires the integrator to reset instantaneously. However, it is very difficult to realize by hardware due to the finite time constant of a reset circuitry, which loads to a large DC offset in the output voltage. Therefore, the paper presents a new control scheme to resolve the problem, which is based on considering a singlephase full-bridge inverter as a buck converter in either positive or negative half load-cycle. Then the amplitude and frequency of the output voltage can be adjusted effectively. Furthermore, by using the dual-buck modulation, the inverter keeps one pair of switches shut during a half load-cycle, which reduces switching loss compared with that of the traditional OCC and avoids a waveform distortion brought by adding dead time. Through theoretical analysis and simulation comparison, it is verified that the half load-cycle OCC can solve the problem of DC offset in the output voltage of the inverter using traditional OCC, while the advantages of the OCC such as constant switching frequency, no multipliers, and simple circuitry are preserved.