Intelligent current analysis for resonant converters

• US 9,494,631 B2
• Filed: 05/05/2013
• Issued: 11/15/2016
• Est. Priority Date: 05/04/2012
• Status: Active Grant

• Current Assignee: Delta Electronics Thailand Public Company Limited (Delta Electronics Incorporated)
• Original Assignee: DET International Holding Limited (Delta Electronics Incorporated)
• Inventors: Davila, Marco Antonio
• Primary Examiner(s): MILLER, DANIEL R
• Application Number:
  US13/887,352
• Publication Number:
  US 20130307559A1
• Time in Patent Office: 1,290 Days
• Field of Search: 320/108, 324/537
• US Class Current: 1/1
• CPC Class Codes: G01R 27/2611 Measuring inductance
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00712 the cycle being controlled or terminated in response to electric parameters
• CPC Class Codes: H02M 3/3387 in a push-pull configuration
• CPC Class Codes: Y02B 70/10 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 Class Codes: Y02P 80/10 Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier

Abstract

A new method of extracting information from a current waveform for the purpose of controlling a resonant converter is presented. The method comprises the step of sampling the converter waveform exactly three times in half a period of the converter waveform or sampling the converter waveform exactly at three different positions in a sequence on different periods of the converter waveform and the step of extracting waveform information to produce a fundamental component and a triangular component of the converter waveform. The information could also be used for the purpose of predicting the inductance and load of a circuit to indicate alignment in a inductive charging system.

Claims

1. A method of acquiring and analyzing a converter waveform of a half-bridge converter having a switching frequency range, comprising sampling the converter waveform at an output of the half-bridge converter exactly 3 times in half a period of the converter waveform or sampling the converter waveform exactly at 3 different positions in a sequence on different periods of the converter waveform and extracting current information of the waveform to produce a fundamental component and a triangular component of the converter waveform, wherein the extracted current information is used to determine a reactive current and a resistive current in the half-bridge converter, and wherein the switching frequency range of the half-bridge converter is controlled dynamically based on the determined reactive and resistive currents.

2. The method of claim 1, including the step of extracting a phase information from the fundamental component.

3. The method of claim 1, including the step of using the extracted current information of the waveform to predict load and inductance information about a circuit.

4. The method of claim 3, including the step of using the extracted current information of the waveform to provide an indication of alignment of a magnetic circuit in a wireless inductive charging system.

5. The method according to claim 1, including determining a safety zone of frequencies.

6. The method according to claim 1, including the step of analyzing the converter waveform of the half-bridge converter.

7. The method according to claim 6 including the steps of determining an inductance of the half-bridge converter and analyzing if the inductance of the system is within operating parameters.

8. The method according to any of the claim 6, including the step of determining the power delivery from a primary circuit of the resonant converter to a secondary circuit of the resonant converter.

9. The method according to claim 4, including the step of determining if a secondary circuit of the converter is unable to produce power in the wireless inductive charging system.

10. A Half-bridge Converter configured to perform any of the methods according to claim 1.

11. Wireless inductive charging system including a converter according to claim 1.