CONTROL CIRCUITS AND METHODS FOR DISTRIBUTED INDUCTION HEATING DEVICES

• US 20190327792A1
• Filed: 04/23/2018
• Published: 10/24/2019
• Est. Priority Date: 04/23/2018
• Status: Active Application

• Current Assignee: Whirlpool Corporation
• Original Assignee: Whirlpool Corporation
• Inventors: Baldo, Salvatore, Forgione, Marco, Gallivanoni, Andrea, Pastore, Cristiano Vito
• Application Number:
  US15/959,983
• Publication Number:
  US 20190327792A1
• Time in Patent Office: Days
• CPC Class Codes: H02M 7/06 using discharge tubes without control electrode or semiconductor devices without control electrode
• CPC Class Codes: H02M 7/4815 Resonant converters H02M7/4811 and H02M7/4826 take precedence
• CPC Class Codes: H02M 7/5395 by pulse-width modulation
• CPC Class Codes: H05B 2213/03 Heating plates made out of a matrix of heating elements that can define heating areas adapted to cookware randomly placed on the heating plate
• CPC Class Codes: H05B 6/062 for cooking plates or the like
• CPC Class Codes: H05B 6/065 using coordinated control of multiple induction coils
• CPC Class Codes: H05B 6/1209 induction cooking plates or the like and devices to be used in combination with them
• 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

An induction heating device comprises a D.C. power supply referenced to a ground connection. The D.C. power supply is configured to supply power to the induction heating device and comprises a voltage rectifier configured to rectify an input voltage into a direct current and output the D.C. voltage to a D.C. bus and a ground connection. The device further comprises a plurality of resonant loads arranged in a matrix comprising a plurality of columns and a plurality of rows. Each of the resonant loads is connected at a first end to a row and at a second end to a column. A plurality of first switching devices are in connection with each of the columns between the D.C. bus and at least one of the resonant loads. A plurality of second switching devices are in connection with each of the rows between the resonant loads and the ground connection.

Claims

1. An induction heating device comprising:

a D.C. power supply, referenced to a ground connection, configured to supply power to the induction heating device and comprising a voltage rectifier, configured to rectify an input voltage into a direct current and output the D.C. voltage to a D.C. bus and a ground connection;

a plurality of resonant loads arranged in a matrix comprising a plurality of columns and a plurality of rows, wherein each of the resonant loads is connected at a first end to a row and at a second end to a column;

a plurality of first switching devices in connection with each of the columns between the D.C. bus and at least one of the resonant loads; and

a plurality of second switching devices in connection with each of the rows between the resonant loads and the ground connection.

2. The device according to claim 1, wherein the resonant loads comprise a capacitor and an inductor connected in parallel.

3. The device according to claim 1, further comprising:

a rectifying device connected in series on an anode side to each of the resonant loads and on a cathode side to each of the rows and the second switching devices.

4. The control circuit according to claim 3, wherein the rectifying device is configured to block reverse-current returning through the rows or columns into the resonant loads.

5. The device according to claim 1, further comprising:

a rectifying device connected in series between the first switching devices on an anode side and each of the resonant loads on a cathode side.

6. The control circuit according to claim 5, wherein the rectifying device is arranged such that current is conducted directionally from the D.C. bus into the resonant load through the first switching device.

7. The device according to claim 1, wherein each of the plurality of rows and the plurality of columns are transposed forming a transposed arrangement.

8. The device according to claim 1, wherein the first switching devices are disposed between the D.C. bus and each of the columns.

9. The device according to claim 8, wherein each column being connected to more than one of the resonant loads.

10. The device according to claim 1, wherein each of the second switching devices is disposed between the ground connection and each of the rows.

11. The device according to claim 10, wherein each of the rows is connected to more than one of the resonant loads.

12. The device according to claim 1, wherein the resonant loads comprise an inductor and a capacitor arranged in parallel and the first switching devices and the second switching devices form a plurality of non-underclamped quasi-resonant inverters, each comprising the resonant loads arranged in series with a rectification device.

13. The device according to claim 12, further comprising:

a controller configured to selectively activate each non-underclamped quasi resonant inverter by controlling a combination of the first switching devices and the second switching devices.

14. A method for controlling an induction heating device comprising:

selectively supplying D.C. power from a rectified power supply to a plurality of columns of a matrix of resonant loads through a plurality of first switches;

controlling a first switching signal of the first switching devices in connection with each of the columns between the power supply and the resonant loads;

controlling a second switching signal of a plurality of second switching devices in connection with each of a plurality of rows of the matrix between the resonant loads and a ground connection, and

selectively conducting current from the power supply through at least one selected resonant load of the resonant loads in response to an activation of the first switching device in connection to a selected resonant load in combination with an activation of the second switching device in connection with the selected resonant load.

15. The method according to claim 14, wherein each of the resonant loads comprise a capacitor and an inductor connected in parallel between an input node and an output node, wherein each of the input nodes is in connection with one of the first switching device and each of the output nodes is connected to one of the second switching device.

16. The method according to claim 14, further comprising:

directionally conducting the current through a rectifying device in connection between each of the resonant loads and the first switching devices or the second switching devices.

17. The method according to claim 14, further comprising:

directionally conducting the current through a rectifying device in connection between each of the resonant loads and a corresponding row of the plurality of rows or a corresponding column of the plurality of columns.

18. The method according to claim 14, wherein controlling the first switching signal selectively conducts current from the D.C. bus into an input node of the at least one selected resonant load.

19. The method according to claim 18, further comprising:

supplying the current from the input node into a capacitor and an inductor connected in parallel forming the at least one selected resonant load;

emitting the current from an output node formed by the parallel connection of the capacitor and the inductor; and

directionally conducting the current from the output node to the second switching device, wherein the directionally conducting the current comprises blocking a reverse current passing from the second switching device into the resonant load.

20. An induction heating device comprising:

a D.C. power supply, referenced to a ground connection, configured to supply power to the induction heating device via a D.C. bus;

a plurality of resonant loads, each comprising a first node and a second node, arranged in a matrix comprising a plurality of columns and a plurality of rows, wherein each of the resonant loads is connected at the first node to a column and the second node to a row;

a plurality of first switching devices, each of the first switching devices in connection with one of the columns between the D.C. bus and the resonant loads;

a plurality of second switching devices, each of the second switching devices in connection with one of the rows between the resonant loads and the ground connection; and

a rectifying device connected in series with each of the resonant loads, wherein the rectifying device defines a directional current flow path through each of the resonant loads.