717 publications from this institution
This paper presents control and performance of a pulse-density-modulated (PDM) series-resonant voltage-source inverter developed for corona discharge processes. The PDM inverter produces either a square-wave ac-voltage state or a zero- voltage state at its ac terminals to control the average output voltage under constant dc voltage and operating frequency. This results in a wide range of power control from 0.5% to 100%, even in the corona discharge load with a strong nonlinear char- acteristic. A 30-kHz 6-kW surface treatment system consisting of a voltage-source PDM inverter, a step-up transformer, and a corona discharge treater shows the establishment of a stable corona discharge in an extremely wide range of power control and, therefore, succeeds in performing both strong and weak surface treatment processes for film.
This paper presents a high-efficiency bidirectional isolated dc-dc converter for a battery energy storage system connected to the grid. It discusses the design of the converter, an optimal operating frequency range, and the optimal dead times for a 6-kW, full-bridge, bidirectional isolated dc-dc converter with focus on improving converter efficiency. This paper also provides a power-loss breakdown of the dc-dc converter at the rated power. The optimal frequency range of the dc-dc converter is defined by making its frequency-dependent loss equal to its frequency-independent loss. The optimal dead time is defined by one-fourth of the resonant period. The maximum efficiency of the dc-dc converter operating at 4 kHz is measured at 98.1% during battery charging and at 98.2% during battery discharging. The converter maintains a high efficiency of more than 97% in a wide range of power transfer.
