The bidirectional LLC resonant converter operated at fixed switching frequency is a preferable candidate for a true dc transformer that does not actively control the power flow. This is due to its naturally stiff voltage ratio regardless of the imposed loa ...
The dc transformers based on an LLC converter operated in open loop near resonant frequency have several crucial advantages compared to other topologies. These advantages are the stiff voltage ratio with a natural power flow, the dc grid isolation via medi ...
The duty-cycle control is a popular option for current limiting in LLC resonant converters. Such current limiting is required to protect the converter either during the start-up or during an overload. Although this method proved to be effective, the switch ...
Recently, IGCTs have shown a great potential for the soft-switching dc transformer applications based on LLC resonant converter. The zero-voltage switching that is present in this converter topology enables an operation of IGCTs without clamping circuit an ...
The invention relates to a gate unit (22) for controlling a gate commutated thyristor (21), comprising: - a voltage selector (26) for selectively applying a high supply potential (Vpos), a middle supply potential (Vmid), and a low supply potential (Vneg); ...
The present invention relates to a method for operating a resonant power converter (1) having a primary stage (2) and a secondary stage (3) at least one of which is actively operated and includes a half-bridge or full-bridge inverter (21) having a pull-up ...
The present invention relates to a DC/DC converter (1) for transferring an active power between two DC subsystems (5, 6) comprising: - a first converter stage (3) and a second converter stage (4) both configured to be selectively operated as an active inve ...
IGCTs have successfully demonstrated to be well-suited devices for an application in medium-voltage dc transformers based on LLC resonant converter topology. This application enables unusually high switching frequencies in kHz range thanks to the zero-volt ...
This paper presents an IGCT unit that has been tailored for emerging soft-switching high-power applications. Redefining the state-of-the-art design and driving concepts, the size and consumption of the proposed unit can be reduced significantly. The paper ...
The required module capacitances of modular multilevel converters can be significantly reduced in comparison to conventional operation modes when quasi-two-level operation is applied. Unfortunately, the output voltage distortion becomes similar to those of ...