Queen's University at Kingston

Magna International Inc.

Magna Powertrain Gmbh & Co. Kg

Wenbo Liu

Yan-Fei Liu

Yang Chen

Bo Sheng

Gerd Schlager

Lakshmi Varaha Iyer

Wolfgang Baeck

Michael Neudorfhofer

Xiang Zhou

Andrew Yurek

Binghui He

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.

Method and system for balancing multi-phase LLC power converter with switch-controlled capacitors

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.

Power converter with integrated multi-layer cooling

A control circuit for an isolated power converter includes a first sensing circuit that senses a secondary side output voltage and produces a pulse wave modulation (PWM) signal having a duty cycle that is proportional to a value of the secondary side output voltage. The PWM is transferred across the converter isolation barrier to the primary side, and a primary side circuit receives the PWM signal and outputs a control signal. A controller determines the value of the secondary side output voltage from the control signal and uses the value to control primary side power switching devices of the isolated power converter to regulate the secondary side output voltage at a selected value.

Methods and circuits for sensing isolated power converter output voltage across the isolation barrier

Controllers and methods for controlling a resonant power converter output voltage include operating the power converter according to a control period comprising an on cycle operation mode for a duration T_on that produces a first voltage Voand an off cycle operation mode for a duration T_off that produces a second voltage Vo. Vois produced using a first switching frequency for a first selected number of switching cycles corresponding to the on time T_on. The converter output voltage or the converter input and output voltages may be sensed and used to determine the switching frequency during the on cycle operation mode and the duration of the off cycle operation mode. The final output voltage of the power converter is regulated to a selected value based on a ration of (T_on):(T_on+T_off). The controllers and methods may be used with power converters in power delivery devices to accept wide input voltage ranges compatible with devices such as cell phones, tablet computers, and notebook computers.

Power cycle modulation control for power converters

Growing community of inventors

Kingston, Canada

Wenbo Liu