| Summary: | 碩士 === 國立臺北教育大學 === 資訊科學系碩士班 === 97 === In this thesis, a field programmable gate array (FPGA) - based harmonic elimination pulse width modulation (HEPWM) generator for an uninterruptible power supply is proposed. The HEPWM generator is developed in two steps. First, the off-line computations of switching patterns based on harmonic elimination strategy are stored in EPROM. Then, the circuits for adjustments of modulation index and phase angle are synthesized onto a FPGA by means of hardware description language (VHDL). The developed chip applied to an uninterruptible power supply which is composed of a series lead-acid battery, a push-pull converter and two half bridge inverters each supplying a separate single-phase load at 220VAC, 60Hz. In order to meet the required load voltage and reduce the space occupied by the batteries, the push-pull converter is used to boost the 36VDC from series batteries to 320VDC at a switching frequency of 29.4kHz. The switching patterns of the push-pull converter are also programmed into the FPGA. Experimental results from 1kVA FPGA-based laboratory UPS verifies the effectiveness and accuracy of the proposed configuration.
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