Resonant converters with variable inductor

• US 9,979,273 B2
• Filed: 05/19/2016
• Issued: 05/22/2018
• Est. Priority Date: 05/19/2016
• Status: Active Grant

• Current Assignee: ABB Schweiz AG (ABB Limited)
• Original Assignee: ABB Schweiz AG (ABB Limited)
• Inventors: Suryanarayana, Harish, Liang, Jiaqi, Kittila, Jukka-Pekka, Ouyang, Wen
• Primary Examiner(s): Gblende, Jeffrey
• Assistant Examiner(s): Singh, David A.
• Application Number:
  US15/159,159
• Publication Number:
  US 20170338730A1
• Time in Patent Office: 733 Days
• CPC Class Codes: H01F 2029/143 with control winding for generating magnetic bias
• CPC Class Codes: H01F 21/08 by varying the permeability of the core, e.g. by varying magnetic bias
• CPC Class Codes: H01F 27/24 Magnetic cores
• CPC Class Codes: H01F 27/28 Coils; Windings; Conductive connections
• CPC Class Codes: H01F 27/2895 Windings disposed upon ring cores
• CPC Class Codes: H01F 29/14 with variable magnetic bias amplitude modulation by means of variable impedance element H03C1/08 ; magnetic amplifiers H03F; circuits for automatic telephonic communication H04M3/00
• CPC Class Codes: H01F 3/14 Constrictions; Gaps, e.g. air-gaps in magnetic shunt paths H01F3/12
• CPC Class Codes: H02M 1/0058 by employing soft switching techniques, i.e. commutation of transistors when applied voltage is zero or when current flow is zero using an auxiliary actively switched resonant commutation circuit connected to an intermediate DC voltage or between two push-pull branches of an inverter bridge H02M7/4811; in resonant inverters H02M7/4815; in inverters operating from a resonant DC source H02M7/4826
• CPC Class Codes: H02M 7/003 Constructional details, e.g. physical layout, assembly, wiring or busbar connections
• CPC Class Codes: H02M 7/4815 Resonant converters H02M7/4811 and H02M7/4826 take precedence
• CPC Class Codes: H02M 7/4818 with means for adaptation of resonance frequency, e.g. by modification of capacitance or inductance of resonance circuits
• CPC Class Codes: H02M 7/5387 in a bridge configuration
• CPC Class Codes: H02M 7/797 using semiconductor devices only
• 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

Abstract

Unique systems, methods, techniques and apparatuses for a ZVT ZCT resonant converter with a variable resonant tank are disclosed. One exemplary embodiment is a system comprising a bidirectional resonant converter comprising an input/output terminal, a switching device coupled with the input/output terminal, a resonant circuit coupled with the switching device and including a variable inductor, an output/input terminal coupled with the resonant circuit, and a DC biasing circuit operatively coupled with the variable inductor. The variable inductor comprises a toroidal core, a first winding wound around the toroidal core and coupled with the switching device and the output/input terminal, a second core structured to overlap a portion of the toroidal core, and a second winding wound around the second core and coupled with the DC biasing circuit. The DC biasing circuit is controllable to vary the inductance of the variable inductor by saturating a portion of the toroidal core.

Claims

1. A system comprising:

a bidirectional resonant converter comprising an input/output terminal, a switching device coupled with the input/output terminal, a resonant circuit coupled with the switching device and including a variable inductor, an output/input terminal coupled with the resonant circuit, and a DC biasing circuit operatively coupled with the variable inductor;

wherein the variable inductor comprises a toroidal core, a first winding wound around the toroidal core and coupled with the switching device and the output/input terminal, a second core structured to overlap a portion of the toroidal core, and a second winding wound around the second core and coupled with the DC biasing circuit; and

wherein the DC biasing circuit is controllable to vary an inductance of the variable inductor by saturating the portion of the toroidal core with magnetic flux.

2. The system of claim 1 wherein the second core comprises a cylindrical portion positioned within a center of the toroidal core and top and bottom plate portions extending radially outward to overlap the portion of the toroidal core.

3. The system of claim 1 wherein the second core comprises a C-shaped structure including a top portion overlapping the toroidal core, a middle portion around which the second winding is wound, and a third portion overlapping the toroidal core.

4. The system of claim 1 wherein the variable inductor comprises a third core structured to overlap a second portion of the toroidal core, and a third winding wound around the third core and coupled with a second DC biasing circuit, the second DC biasing circuit being controllable to vary the inductance of the variable inductor by saturating the second portion of the toroidal core with magnetic flux.

5. The system of claim 1 wherein a first flux path through the toroidal core for the first winding is toroidal and a second flux path through the toroidal core for the second winding is perpendicular to the first flux path.

6. The system of claim 1 wherein the toroidal core comprises an air gap positioned such that the air gap and the first winding overlap along the portion of the toroidal core.

7. A method comprising:

operating resonant converter circuitry including a first switching device operatively coupled with a first input/output terminal and a resonant tank, the resonant tank including a variable inductor, the variable inductor including a first core, a first winding wound around the first core and operatively coupled with the first switching device, a second core, and a second winding wound around the second core, a second switching device operatively coupled with the first winding of the variable inductor and a second input/output terminal, and an electronic control system operatively coupled with the first switching device and the second switching device and structured to control current to the second winding;

operating the electronic control system to provide a current through the first winding of the variable inductor, provide a current through the second winding of the variable inductor so as to alter an inductance of the variable inductor, provide power to the second switching device from the resonant tank such that a voltage and current applied to the second switching device by the resonant tank are substantially equal to a current and voltage provided to the second switching device by the second input/output terminal, and open the second switching device during a zero-voltage, zero-current condition.

8. The method of claim 7 comprising:

receiving voltage and load current requirements with the electronic control system;

calculating with the electronic control system a desired resonant tank impedance using the voltage and load current requirements; and

operating the electronic control system to provide a current to the second winding of the variable inductor with the electronic control system in response to the calculating of the desired resonant tank impedance.

9. The method of claim 8 wherein the electronic control system is structured to operate the first switching device by opening and closing the first switching device at resonant frequency so as to provide a resonant current to the second input/output terminal.

10. The method of claim 9 comprising:

operating circuitry including a third winding wound around the second core and coupled with the electronic control system;

calculating a change in resonant tank impedance using the voltage and load requirements; and

providing a current to the third winding of the variable inductor in response to the calculating of the desired resonant tank impedance.

11. The method of claim 7 wherein the electronic control system comprises a plurality of microprocessor based controllers.

12. The method of claim 7 wherein the resonant converter is structured and controlled to output AC power.