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US 10,447,147 B2Granted
DC/DC resonant converters and power factor correction using resonant converters, and corresponding control methods
AssigneeSignify Holding B.V.
InventorsJohannes Hubertus Gerardus Op Het Veld, David Llewellyn John, Reinhold Elferich, William Peter Mechtildis Marie Jans
Life of this patent
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Abstract
Various improvements are provided to resonant DC/DC and AC/DC converter circuit. The improvements are of particular interest for LLC circuits. Some examples relate to self-oscillating circuit and others relate to converter circuits with frequency control, for example for power factor correction, driven by an oscillator.
Claims9
An AC/DC PFC converter, comprising:
- an AC input;
- a rectifier;
- a half bridge inverter comprising a first switch and a second switch, wherein an output is defined from a node between the first and second switches;
- a self-oscillating LLC circuit coupled to the output, the self-oscillating LLC circuit being arranged to provide an electrical feedback parameter;
- and
- a control circuit for generating a gate drive signal for controlling switching of the first and second switches in dependence on the electrical feedback parameter, wherein a high gate drive signal turns on the first switch and turns off the second switch and a low gate drive signal turns off the first switch and turns on the second switch,
- wherein the control circuit is for determining a first time duration corresponding to an on-time of the first switch and for determining a second time duration corresponding to an on-time of the second switch, the duty cycle of the second switch having a defined value,
- and wherein the control circuit further comprises an integrator for:
- integrating a first constant value until the control circuit detects that the electrical feedback parameter reaches a threshold value defining the first time duration;
- subsequently integrating a second constant value of opposite sign to the first constant value defining the second time duration;
- wherein the first and second constant values are derived from the gate drive signal;
- wherein the integrator has a reference input set to a fixed voltage within a range of the gate drive signal;
- and
- wherein the integrator has the reference input set to a mid-point of the gate drive signal.
11 more elements
An AC/DC PFC converter, comprising:
- an AC input;
- a rectifier;
- a half bridge inverter comprising a first switch and a second switch, wherein an output is defined from a node between the first and second switches;
- a self-oscillating LLC circuit coupled to the output, the LLC circuit being arranged to provide an electrical feedback parameter;
- and
- a control circuit for generating a gate drive signal for controlling the switching of the first and second switches in dependence on the electrical feedback parameter, wherein a high gate drive signal turns on the first switch and turns off the second switch and a low gate drive signal turns off the first switch and turns on the second switch,
- wherein the control circuit is for determining a first time duration corresponding to an on-time of the first switch and for determining a second time duration corresponding to an on-time of the second switch, the duty cycle of the second switch having a defined value,
- and wherein the control circuit further comprises an integrator for:
- integrating a first constant value until the control circuit detects that the electrical feedback parameter reaches a threshold value defining the first time duration;
- subsequently integrating a second constant value of opposite sign to the first constant value defining the second time duration;
- and an RC output filter at an output of the integrator.
8 more elements
An AC/DC PFC converter, comprising:
- an AC input;
- a rectifier;
- a half bridge inverter comprising a first switch and a second switch, wherein an output is defined from a node between the first and second switches;
- a self-oscillating LLC circuit coupled to the output, the self-oscillating LLC circuit being arranged to provide an electrical feedback parameter;
- and
- a control circuit for generating a gate drive signal for controlling the switching of the first and second switches in dependence on the electrical feedback parameter, wherein a high gate drive signal turns on the first switch and turns off the second switch and a low gate drive signal turns off the first switch and turns on the second switch,
- wherein the control circuit is for determining a first time duration corresponding to an on-time of the first switch and for determining a second time duration corresponding to an on-time of the second switch, the duty cycle of the second switch having a defined value,
- and wherein the control circuit further comprises an integrator for:
- integrating a first constant value until the control circuit detects that the electrical feedback parameter reaches a threshold value defining the first time duration;
- subsequently integrating a second constant value of opposite sign to the first constant value defining the second time duration;
- and wherein the electrical feedback parameter comprises a voltage across a capacitor of the LLC circuit.
8 more elements
An AC/DC PFC conversion method, comprising:
- rectifying an AC input;
- operating a half bridge inverter comprising a first switch and a second switch using a gate drive signal and providing an output from a node between the switches, wherein a high gate drive signal turns on the first switch and turns off the second switch and a low gate drive signal turns off the first switch and turns on the second switch;
- providing an electrical feedback parameter from a self-oscillating LLC circuit coupled to the output, wherein the electrical feedback parameter is provided by the self-oscillating LLC circuit;
- controlling switching of the first and second switches by:
- determining a first time duration corresponding to an on-time of the first switch and determining a second time duration corresponding to an on-time of the second switch, and
- integrating a first constant value until the electrical feedback parameter reaches a threshold value defining the first time duration;
- and
- subsequently integrating a second constant value of opposite sign to the first constant value defining the second time duration;
- and
- wherein the constant values are derived from the gate drive signal, and the step of integrating includes setting a reference input to a fixed voltage within the range of the gate drive signal and the reference input set to the mid-point of the gate drive signal.
7 more elements
Dependencies are inferred from the claim text.