Karsten Handt

Fully digitised, quasi-continuous working gate-drive unit for 1200V-IGBT

IGBT, field programmable gate array (FPGA), switching losses, high power discrete device, converter control, Efficiency Improving the performance of prospective inverters can not only be realised by advanced power semiconductors and faster signal-processing components on its own. Even the circuitry that combines all together opens up new possibilities. So, the gate-drive unit takes a central place in an inverter to increase power density and efficiency. This paper presents a digitised gate-drive unit for 1200V-IGBTs that works in a quasi-continuous manner. Its inner digital signal-processing is done by a FPGA. The publication describes the design, the implemented main features and the schematic functionality of this novel gate-drive unit. Furthermore, there is a summary of the potential to adjust the behaviour of the IGBT, the diode and the whole inverter. An outlook, which shows the major advantages of this gate-drive unit and their practically use for achieving the proposed aims, finally concludes.

A modular bi-directional hybrid circuit breaker for medium and high voltage DC networks

The development of dc transmission and distribution technologies are gaining traction. With renewable energy being fed to the grid constantly increasing, there is growing interest in development of dc grids. A major hindrance for their development is attributed to the lack of protection during short-circuit fault. Hybrid circuit breakers, a combination of mechanical and semi-conductor devices are understood to be the most effective method to protect dc grids against such faults. Several of such hybrid breakers are published and patented but still a practical high voltage dc breaker has not been developed. In this paper a novel modular hybrid circuit breaker is presented. This paper tries to address limitations present in existing breakers and a scalable model which can be used for both medium and high voltage dc networks is proposed.