Series connecting devices for high-voltage power conversion

Abstract

Novel dynamic voltage-sharing schemes have been developed to allow any high-voltage power-semiconductor device, e.g. thyristor, IGCT, IGBT or power MOSFET, to be series-connected in strings, and switched as simply and rapidly in high-voltage applications as single devices. The circuits have many of the advantages of simply using RC or RCD snubbers, including being easily applicable to both low-and high-side switches. However, because the snubber capacitors are not fully discharged their associated reset current and power-losses are minimized. To illustrate the principle of operation experimentally, a string of three series-connected power MOSFETs switching 100A from 330 V has been used to obtain practical waveforms. The schemes are discussed and illustrated, using SPICE simulation results. The new, relatively simple voltage-sharing schemes are much easier to design and optimize than recently reported active gate-control and regenerative-snubber methods, allow very rapid turn-on and turn-off switching, and give compositedevice switches a usable voltage rating similar to the aggregated voltage ratings of the string.

Design of High Voltage Full-Bridge Inverter Using Marx Derived Switches

“…However, even small variations of devices static and dynamic parameters, the imperfect synchronization or delay of the gate drive voltages, thermal impedance variations and asymmetrical parameters in the snubber circuits for voltage sharing [2], can impair the voltage balance among series semiconductor devices.…”

A 3600 V/80 A Series--Parallel-Connected Silicon Carbide MOSFETs Module With a Single External Gate Driver

“…Drainsource side voltage balancing circuits are connected across the drain and source for each semiconductor power device. Circuits of this category include three different types, namely, the passive snubber circuit [5]- [7], the resonant snubber circuit [8] and the clamping circuit [9], [10]. The voltage balancing circuits of gate side category include active control circuit [11]- [13], synchronous control circuit [14], [15], and active clamping circuit [16]- [20].…”

Novel Converter Solutions with a Modular Multilevel Structure for High-Power Medium-Voltage Electrical Machine Drive Applications

“…In other words, according to (3), by multiplying (1) and ( 2) the MMC capacitor current is obtained. Since both S(t) and i arm (t) are signals with an f o -Hz component and with a DC component, then the capacitor current will be composed of, not only a DC component, but also of an f o = 1-Hz component and of a 2f o = 2-Hz component as illustrated in Fig.…”

“…The M 3 C is an AC-AC converter solution with a modular multilevel structure and its direct AC-AC connection leads to a reduced overall component count, which is an important advantage in relation to the MMC. Nonetheless, in order for the M 3 C to be able to operate as a controlled voltage source from both grid and load perspectives, it must have a large number of FB submodule strings (nine submodule strings in total or three submodule strings per phase), which still results in a relatively high component count. In addition, the M 3 C presents some operational challenges due to its topology.…”

“…The traditional solution available to reach increased voltage levels was to connect in series several semiconductor devices aiming at obtaining a stack capable to behave as a high voltage switch. However, small delays in the turn-on/turn-of time of the many devices in the stack could result in serious problems related to static and dynamic voltage sharing among these devices, which would then result in a solution with poor reliability [1][2][3][4][5][6]. This problem would be particularly critical in flexible voltagesource converters operating with high switching frequencies.…”