Abstract: A power converter includes an integrated multi-layer cooling structure. The power converter includes a plurality of printed circuit boards (PCBs) stacked together in a generally vertical arrangement. A liquid cooling mechanism is attached to a lower-most PCB, and high loss circuitry components are attached to an opposite side of the lower-most PCB. Low loss circuitry components are attached to further PCBs. Magnetic components may be attached to the further PCBs. The high loss components are actively cooled by the liquid cooling mechanism and the low loss components and magnetic components are passively cooled. The liquid cooling mechanism may be a cold plate heatsink. The power converter may include intermediate PCBs disposed between the upper-most PCB and the lower-most PCB, with low loss circuitry components attached to the intermediate PCBs.

Abstract: A switching circuit of a motor drive includes a high-side switch configured to selectively conduct current between a DC positive conductor and an output conductor, and a low-side switch configured to selectively conduct current between the output conductor and a DC negative conductor. The high-side switch comprises a depletion mode (D-Mode) gallium nitride (GaN) high-electron-mobility transistor (HEMT) and a Si-FET in a cascaded configuration, and the low-side switch comprises a D-Mode GaN HEMT. This arrangement can provide a safe state operation in which the switching circuit provides a default condition providing electrical continuity between the DC negative conductor and the output conductor and providing electrical isolation between the DC positive conductor and the output conductor in the event of a loss of control signals.

Abstract: A battery charger for an electric vehicle supplies DC output power to an output bus for supplying power to a battery. The battery charger includes an AC/DC converter using switches to convert AC power from an AC source to a DC link voltage upon a DC link bus. A DC link capacitor allows a ripple in the DC link voltage that is greater than in conventional charger designs. A DC/DC stage includes a DC/AC converter including one or more switches to selectively conduct current from the DC link bus to supply an AC power to a transformer. The switches of the DC/AC converter are mounted to an insulated metal substrate that is in thermal contact with a transformer housing for dissipating heat therefrom. A controller controls one or more switches of the DC/AC converter and varies a switching frequency responsive to the ripple of the DC link voltage.

Abstract: A power electronic converter supplies DC output power to an output bus for supplying a load, such as a battery. The power electronic converter includes a DC link capacitor configured to provide a DC link voltage with a ripple of 80 V peak-to-peak. The power electronic converter also includes a DC/DC stage having a DC/AC converter that includes one or more switches to selectively conduct current from the DC link bus to supply an AC power to a transformer. The switches of the DC/AC converter are mounted to an insulated metal substrate that is in thermal contact with a transformer housing for dissipating heat therefrom. A controller controls one or more switches of the DC/AC converter and varies a switching frequency responsive to the ripple of the DC link voltage.

Abstract: A motor drive system for an electrified vehicle includes a DC source, such as a battery, and an inverter, which includes one or more phase drivers, each configured to switch current from the DC source to generate AC power upon one or more output terminals using a hybrid of two or more different solid-state switches, each having a corresponding voltage rating. A nine-switch inverter includes three phase drivers, each including high, low, and middle solid-state switches, with Si-MOSFET high and low switches having a first voltage rating of half of the rated voltage of the system, and with Gallium Nitride (GaN) transistors rated to block a full rated voltage of the system used for the middle switches. A delay driver synchronizes timing between two different solid-state switches by energizing control terminals at different rates. The inverter can be operated using near-state pulse-width modulation (NSPWM) to reduce switching losses.

Abstract: A multi-phase LLC power converter comprises a plurality of LLC phases each including a resonant tank and a switching stage. The resonant tank includes a resonant inductor, a resonant capacitor, and a parallel inductance. The switching stage switches an input power at an operating frequency to apply a switched power to the resonant tank, with the switched power approximating an alternating current (AC) waveform having a switching frequency. A secondary-side controller varies the switching frequency to control an output voltage of the multi-phase LLC power converter. A primary-side controller measures primary-side currents, calculates an initial switch-controlled capacitor (SCC) conduction phase angle for each of the LLC phases, and operates an SCC switch in accordance with an SCC conduction phase angle to adjust the capacitance of the resonant capacitor of an LLC phase to cause each of the LLC phases to have equal resonant frequencies.

Abstract: An LLC power converter comprises a switching stage and a resonant tank, the switching stage configured to switch an input power at a switching frequency to apply a switched power to the resonant tank, and the resonant tank includes a resonant inductor, a resonant capacitor, and a parallel inductance. A transformer has a primary winding connected to the resonant tank and a secondary winding. A synchronous rectifier (SR) switch is configured to selectively switch current from the secondary winding to supply a rectified current to a load. An RC filter includes a filter capacitor and a filter resistor connected across the SR switch, with the filter capacitor defining a filter capacitor voltage thereacross. A rectifier driver is configured to drive the SR switch to a conductive state in response to the filter capacitor voltage being less than a threshold value.

Abstract: An inductor-inductor-capacitor (EEC) power converter with high efficiency for Electric Vehicle (EV) on-board low voltage DC-DC chargers (LDC) is disclosed. The converter includes a switching bridge with a plurality of bridge switches and configured to generate an output from a direct current input voltage. An EEC tank circuit is coupled to the switching bridge and includes a resonant inductor and a resonant capacitor and a parallel inductor connected between the resonant inductor and the resonant capacitor. The tank circuit is configured to output a resonant sinusoidal current from the output of the switching bridge. At least one transformer has at least one primary winding in parallel with the parallel inductor of the inductor-inductor-capacitor tank circuit and at least one secondary winding. At least one rectifier is coupled to the at least one secondary winding and is configured to output a rectified alternating current.

Abstract: A power converter includes an integrated multi-layer cooling structure. The power converter includes a plurality of printed circuit boards (PCBs) stacked together in a generally vertical arrangement. A liquid cooling mechanism is attached to a lower-most PCB, and high loss circuitry components are attached to an opposite side of the lower-most PCB. Low loss circuitry components are attached to further PCBs. Magnetic components may be attached to the further PCBs. The high loss components are actively cooled by the liquid cooling mechanism and the low loss components and magnetic components are passively cooled. The liquid cooling mechanism may be a cold plate heatsink. The power converter may include intermediate PCBs disposed between the upper-most PCB and the lower-most PCB, with low loss circuitry components attached to the intermediate PCBs.