Hella Gmbh & Co Kgaa

Philip Michael Johnson

Alan Wayne Brown

Allan Ray Taylor

A converter for electrical connection to a three-phase electrical grid and a single-phase electrical grid is provided. The converter includes three DAB modules, each for converting a respective alternating current of a three-phase electrical grid. When connected to a single-phase electrical grid, the third DAB module is bi-directional such that it is operable to filter the power output of the first and second DAB modules. The converter further includes a filter capacitor in electrical communication with the third DAB module through a relay, wherein the relay is responsive to a controller to couple the third DAB module to the filter capacitor when the single-phase electrical grid is detected and to couple the third DAB module to a grid rectifier when the three-phase electrical grid is detected.

Active filter for single phase charging using a switch-mode converter

An improved method for zero-voltage switching (ZVS) of a voltage-fed half-bridge using a variable dead band is provided. The duration of the dead band is determined dynamically and is precisely long enough to ensure the absence of shoot-through events while also minimizing or eliminating switching losses and reverse conduction losses. The method generally includes: (a) calculating the equivalent capacitance as seen by the current source charging the midpoint of the half-bridge; (b) calculating the ZVS charge requirement based on the link voltage and the equivalent capacitance; (c) calculating the charge delivered by the current source over time during a dead band vector, equating the result to the ZVS charge requirement, and solving for the ZVS time requirement at each commutation point over the switching cycle; and (d) updating the dead bands for each commutation of each half-bridge in the switched-mode power converter.

Half-bridge with variable dead band control and zero-voltage switching

A power converter is provided. The power converter includes two or more hybrid switching circuits electrically connected to a source or storage element. Each switching circuit includes a wide bandgap device that is parallel-connected to a silicon-based device. The converter further includes a controller that is operatively coupled to each device of the first and second switching circuits. The controller is configured to operate each hybrid switching circuit by (i) activating the silicon-based device for an activation period, (ii) activating the wide bandgap device for a predetermined duty cycle less than the activation period, (iii) deactivating the silicon-based device while the wide bandgap device is activated, and (iv) deactivating the wide bandgap device. The hybrid switching circuits are sequentially operated to convert an alternating current of a power supply into a link voltage for a power converter, for example.

Performance enhancement of silicon-based device

Multi-phase-shift control of a power converter is provided. The power converter includes a dual-active-bridge (DAB) converter having a transformer, a first H-bridge coupled to the primary winding of the transformer, and a second H-bridge coupled to the secondary winding of the transformer. The DAB converter is operable to generate two-level and three-level voltage waveforms on the primary winding and on the secondary winding to yield a system which ensures zero-voltage switching and unity power factor over a wide range of input and output voltage levels and power throughputs. In a multi-phase shift (MPS) mode of operation, the DAB converter changes from a two-level voltage in at least one of the windings to a three-level voltage in both windings in response to the instantaneous load being below a predetermined level, resulting in more efficient performance of the DAB converter in light load conditions.

Multi-phase-shift control of a power converter

A control circuit for converting an unbalanced grid voltage into a DC voltage is provided. The control circuit includes a controller having a voltage detection module, a first transformation module, a level shift module, and a second transformation module. The voltage detection module provides voltage component values indicating the voltage in each phase of a three-phase AC power supply. The first transformation module converts the voltage component values from a stationary reference frame into reference voltage signals in a rotating reference frame using a Clarke-Park transform. The level shift module compensates the reference voltage signals to simulate a balanced three-phase AC voltage. The second transformation module converts the compensated reference voltage signals from the rotating reference frame to the stationary reference frame using an inverse Clarke-Park transform. The controller operates a single stage DAB converter for providing a DC charging voltage to a battery that is substantially free of fluctuations.

Growing community of inventors

Brighton, MI, United States of America

Philip Michael Johnson