The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The modulation strategy proposed in this paper enables wide-range zero voltage switching (ZVS) operation of a three-level three-phase dual active bridge (DAB) dc-dc converter. The circuit topology is analyzed and piece-wise linear equations are derived for most appropriate switching modes. Based on the results of a numerical optimizer a modulation scheme is derived, utilizing analytic equations. Compared...
This paper investigates a three-level three-phase Dual Active Bridge (DAB) dc-dc converter with a star-delta connected transformer. The soft-switching region is analyzed for two and three-level operation, using symmetrical voltage waveforms, showing an increased ZVS range for three-level operation. A large number of switching modes are identified and are modeled with piecewise-linear equations. To...
This paper analyzes a three-phase Dual Active Bridge (DAB) dc-dc converter with three-level phase-legs, showing a significant increase in the soft-switching region compared to two-level operation. A strategy is presented that results in a Zero Voltage Switching (ZVS) modulation scheme that relies on analytical equations, uses a small amount of switching modes, and obtains close-to-minimal rms currents.
A three-phase dual active bridge (DAB) converter with three-level phase-legs is analyzed, showing an increased soft-switching region and a reduction in rms current in the ac-link for unequal input and output voltages compared to the conventional two-level circuit. Furthermore, a comparison of the semiconductor losses is carried out for different three-level inverter implementations using commercially...
Commercially available electrical machines are generally not optimized for a broad operating range, as required in e.g. vehicle traction applications. The required mechanical angular velocity of the wheels for electrical vehicle propulsion is relatively low (around 1,000 rpm), while the torque demand is high (around 500 Nm). This combination requires an adequate solution in the mechanical, electromechanical...
An approach for three-phase AC to DC conversion is proposed, which consists of a single-stage while offering galvanic isolation, soft-switching, bi-directional power flow and a significant reduction of inductive and capacitive energy storage. Two elements enable this approach, namely a neutral voltage-lift capacitor and a Quad Active Bridge (QAB) converter. Moreover, a control strategy is described...
The variation of the temperature in semiconductors, caused by the load profile, results in the long term in material fatigue. A distinction can be made between the average temperature and the temperature swing, where the temperature swing has a significant effect on the lifetime of a semiconductor. Therefore, the auxiliary-pole topology is proposed to reduce the temperature swing of the MOSFETs in...
In existing half/full-bridge high precision amplifiers output distortion is present due to the required switch blanking time. The OCC topology does not require this blanking time but has a much higher total inductor volume compared to the half-bridge. In this paper a patented new topology is introduced that has the advantages of the OCC but with a much lower total inductor volume. The basic operation...
Wide angular velocity operation of an electrical machine is demonstrated by partitioning each of the stator coils of a three-phase configuration. An open-winding machine drive circuit is proposed with which dynamic transitions between machine operating modes can be executed. The principle of operation and the design choices of the required bidirectional series switch are explained and motivated. The...
A dual inverter drive system is proposed, which is capable of boosting the phase voltages applied to an open-winding electric machine. A zero sequence current at the third harmonic of the intended output frequency is added to increase the supply voltage of one inverter, thereby extending the operating range of the machine. The need for a reactive current to weaken the machine field is avoided as a...
Field weakening operation of an electrical machine is a conventional method to extend the angular velocity range of a system above the peak output voltage of the inverter. A downside, however, is that an increased reactive current is required that creates losses but no output torque. A dual voltage source inverter topology is proposed, capable of driving an electrical machine without weakening its...
A fault-tolerant operation method for a dynamic electric vehicle (EV) propulsion system using variable torque/speed characteristics is presented. With this method, the electrically powered vehicle can continue driving with a minimum performance reduction, and without the need for redundant systems on machine or electronics level. One of the possible single module fault scenarios, during which the...
A dynamic propulsion system using variable torque/speed characteristics, designed to realize a machine integrated equivalent of a gearbox is presented. This is achieved through adaption of the machine characteristics, and driven by specialized power electronics, leading to a reconfigurable stator coil arrangement. The concept can for example be used to minimize the overall weight of an electric vehicle...
Moving-magnet planar actuators typically have many stator coils, of which the current is controlled individually. Only the coils that lie directly underneath the translator have to be powered. Hence a large reduction in the number of power amplifiers is possible, thereby reducing system complexity and cost as well. A multiplexer topology based on solid-state switches is proposed to be able to use...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.