Control apparatus and method for current resonance circuit and current resonance power supply

Patent metadata

Field	Value
Publication number	US-10910952-B1
Application number	US-201916686266-A
Country	US
Kind code	B1
Filing date	Nov 18, 2019
Priority date	Oct 18, 2019
Publication date	Feb 2, 2021
Grant date	Feb 2, 2021

Abstract

Embodiments of this disclosure provide a control apparatus and method for a current resonance circuit and a current resonance power supply. The control method includes: performing integration on a resonance current of the current resonance circuit or a switching current of one or more switching elements to generate an integration signal; generating a feedback signal of the current resonance circuit; comparing the integration signal with the feedback signal, and generating a measurement signal according to a comparison result; performing digital filtering on the measurement signal; and according to the measurement signal after filtering, generating a pulse width modulation signal controlling the switching elements.

First claim

The invention claimed is:

1. A control apparatus for a current resonance circuit, which controls one or more switching elements of the current resonance circuit, characterized in that the control apparatus comprises:
an integration circuit configured to perform integration on a resonance current of the current resonance circuit or a switching current of the one or more switching elements to generate an integration signal;
a feedback circuit configured to generate a feedback signal of the current resonance circuit;
a comparison circuit configured to compare the integration signal with the feedback signal, and generate a measurement signal according to a comparison result;
a first digital filtering circuit configured to perform digital filtering on the measurement signal; and
a PWM circuit configured to, according to the measurement signal after filtering, generate a pulse width modulation signal controlling the one or more switching elements.

2. The control apparatus according to claim 1 , wherein the control apparatus further comprises:
a first timer configured to accumulate a time in which the integration signal exceeds the feedback signal or a time in which the feedback signal exceeds the integration signal.

3. The control apparatus according to claim 2 , wherein the first digital filtering circuit performs at least one of the following digital processing on the measurement signal according to a set time and/or a time of the first timer: averaging, neglecting an abnormal value, estimating.

4. The control apparatus according to claim 1 , wherein the feedback circuit comprises:
an analog-to-digital converter configured to convert the received feedback signal from an analog signal into a digital signal;
a second digital filtering circuit configured to perform digital filtering on the analog-to-digital converted feedback signal; and
a digital-to-analog converter configured to convert the digital filtered feedback signal from a digital signal into an analog signal.

5. The control apparatus according to claim 4 , wherein the second digital filtering circuit performs such digital processing on the feedback signal that a dynamic adjustment range is increased and/or a saturation voltage when there is no load is decreased.

6. The control apparatus according to claim 4 , wherein the second digital filtering circuit performs the following digital processing:
Vfb _2= A ×( Vfb _1− Vpc );

where, Vfb_1 is a feedback voltage before the digital processing, Vfb_2 is a feedback voltage after the digital processing, A is a constant of gain adjustment, and Vpc is a saturation voltage when there is no load due to saturation of an electronic element.

7. The control apparatus according to claim 1 , wherein the integration circuit comprises:
an integration capacitor configured to perform integration on a resonance current of the current resonance circuit or a switching current of the one or more switching elements; and
an integration switch configured to perform a switch controlling on the integration capacitor.

8. The control apparatus according to claim 7 , wherein the control apparatus further comprises:
a second timer configured to, according to the digital filtered measurement signal and a synchronization signal of the PWM circuit, generate a reset signal controlling the integration switch.

9. A control method for a current resonance circuit, which controls one or more switching elements of the current resonance circuit, characterized in that the control method comprises:
performing integration on a resonance current of the current resonance circuit or a switching current of the one or more switching elements to generate an integration signal;
generating a feedback signal of the current resonance circuit;
comparing the integration signal with the feedback signal, and generating a measurement signal according to a comparison result;
performing digital filtering on the measurement signal; and
according to the measurement signal after filtering, generating a pulse width modulation signal controlling the one or more switching elements.

10. A current resonance power supply, characterized in that the current resonance power supply comprises:
a current resonance circuit comprising one or more switching elements and a resonance capacitor and configured to convert an input current into an output current;
a load using the output current; and
a control apparatus configured to perform integration on a resonance current of the current resonance circuit or a switching current of the one or more switching elements to generate an integration signal, generate a feedback signal of the current resonance circuit, compare the integration signal with the feedback signal, and generate a measurement signal according to a comparison result, perform digital filtering on the measurement signal, and according to the measurement signal after filtering, generate a pulse width modulation signal controlling the one or more switching elements.

Assignees

• Sanken Electric Co Ltd

Inventors

• Furukoshi Ryuichi
• Ohtake Osamu

Classifications

• H02M3/33573 Primary

  Full-bridge at primary side of an isolation transformer · CPC title

• H02M3/33571

  Half-bridge at primary side of an isolation transformer · CPC title

• H02M3/01

  Resonant DC/DC converters · CPC title

• Y02B70/10

  Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes · CPC title

• H02M1/0054

  Transistor switching losses (periodically suspending operation of switching converter in low power mode H02M1/0035) · CPC title