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EP-3562267-B2 - CONTROL CIRCUITS AND METHODS FOR DISTRIBUTED INDUCTION HEATING DEVICES

EP3562267B2EP 3562267 B2EP3562267 B2EP 3562267B2EP-3562267-B2

Inventors

  • Baldo, Salvatore
  • GALLIVANONI, Andrea
  • FORGIONE, MARCO
  • Pastore, Cristiano Vito

Dates

Publication Date
20260513
Application Date
20190410

Claims (13)

  1. An induction heating device comprising: D.C. power supply (46), referenced to a ground connection (54), configured to supply power to the induction heating device and comprising a voltage rectifier (50), configured to rectify an input voltage into a direct current and output the D.C. voltage to a D.C. bus (48) and a ground connection (54); a plurality of resonant loads (36) arranged in a matrix (62) comprising a plurality of columns (70) and a plurality of rows (72), wherein each of the resonant loads (36) is connected at a first end to a row and at a second end to a column (70); a plurality of first switching devices (74) in connection with each of the columns (70) between the D.C. bus (48) and at least one of the resonant loads (36); and a plurality of second switching devices (76) in connection with each of the rows (72) between the resonant loads (36) and the ground connection (54); wherein the resonant loads (36) comprise a capacitor (42) and an inductor (40) connected in parallel.
  2. The device according to claim 1, further comprising: a rectifying device (34) connected in series on an anode side to each of the resonant loads (36) and on a cathode side to each of the rows (72) and the second switching devices (76).
  3. The device according to claim 2, wherein the rectifying device (34) is configured to block reverse-current returning through the rows (72) or columns (70) into the resonant loads (36).
  4. The device according to claim 1, further comprising: a rectifying device (34) connected in series between the first switching devices (74) on an anode side and each of the resonant loads (36) on a cathode side.
  5. The control circuit according to claim 4, wherein the rectifying device (34) is arranged such that current is conducted directionally from the D.C. bus (48) into the resonant load (36) through the first switching device (74).
  6. The device according to claim 1, wherein each of the plurality of rows (72) and the plurality of columns (70) are transposed forming a transposed arrangement.
  7. The device according to claim 1, wherein the first switching devices (74) are disposed between the D.C. bus (48) and each of the columns (70).
  8. The device according to claim 7, wherein each column (70) being connected to more than one of the resonant loads (36).
  9. The device according to claim 1, wherein each of the second switching devices (76) is disposed between the ground connection (54) and each of the rows (72).
  10. The device according to claim 9, wherein each of the rows (72) is connected to more than one of the resonant loads (36).
  11. The device according to claim 1, wherein the resonant loads (36) comprise an inductor (40) and a capacitor (42) arranged in parallel and the first switching devices (74) and the second switching devices (76) form a plurality of non-underclamped quasi-resonant inverters, each comprising the resonant loads (36) arranged in series with a rectification device.
  12. The device according to claim 11, further comprising: a controller configured to selectively activate each non-underclamped quasi resonant inverter by controlling a combination of the first switching devices (74) and the second switching devices (76).
  13. A method for controlling an induction heating device comprising: selectively supplying D.C. power from a rectified power supply to a plurality of columns (70) of a matrix (62) of resonant loads (36) through a plurality of first switching devices (74); controlling a first switching signal of the first switching devices (74) in connection with each of the columns (70) between the power supply and the resonant loads (36); controlling a second switching signal of a plurality of second switching devices (76) in connection with each of a plurality of rows (72) of the matrix (62) between the resonant loads (36) and a ground connection (54), and selectively conducting current from the power supply through at least one selected resonant load of the resonant loads (36) in response to an activation of the first switching device (74) in connection to a selected resonant load in combination with an activation of the second switching device (76) in connection with the selected resonant load; wherein each of the resonant loads (36) comprises a capacitor (42) and an inductor (40) 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 devices (74) and each of the output nodes is connected to one of the second switching devices (76).

Description

TECHNOLOGICAL FIELD The present disclosure relates to an induction cooktop and, more specifically, to an induction cooktop assembly comprising a plurality of cooking zones. BACKGROUND Induction cooktops are devices which exploit the phenomenon of induction heating for food cooking purposes. The disclosure provides for a variety of improved assemblies for induction cooktops that may improve performance and/or economical manufacture. Such improvements may serve to improve the utilization of induction-based cooking technologies. Accordingly, the disclosure provides for assemblies, systems, and methods for induction cooktops. SUMMARY In an aspect of the invention, an induction heating device according to independent claim 1 is provided. In another aspect of the invention, a method for controlling an induction heating device according to independent claim 13 is provided. In at least another aspect, an induction heating device is disclosed. The device comprises a D.C. power supply, referenced to a ground connection, configured to supply power to the induction heating device via a D.C. bus. The device further comprises a plurality of resonant loads. Each of the resonant loads comprises a first node and a second node arranged in a matrix comprising a plurality of columns and a plurality of rows. Each of the resonant loads is connected to at the first node to a column and the second node to a row. The device further comprises a plurality of first switching devices and a plurality of second switching devices. Each of the first switching devices is in connection with one of the columns between the D.C. bus and the resonant loads. Each of the second switching devices is in connection with one of the rows between the resonant loads and the ground connection. A rectifying device is connected in series with each of the resonant loads. The rectifying device defines a directional current flow path through each of the resonant loads. These and other features, advantages, and objects of the present device will be further understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: FIG. 1A is a top, plan view of an induction cooktop assembly comprising a plurality of induction coils;FIG. 1B is a top, plan view of an induction cooktop assembly comprising a matrix of induction coils;FIG. 2 is a circuit diagram demonstrating a control circuit for a single, non-under-clamped quasi-resonant inverter;FIG. 3A demonstrates simulated results for a system response of the control circuit shown in FIG. 2 over a time interval;FIG. 3B demonstrates simulated results for a system response of the control circuit shown in FIG. 2 over a time interval;FIG. 4 is a circuit diagram demonstrating a control circuit for a matrix of non-under-clamped quasi-resonant inverters;FIG. 5 is a circuit diagram modified from the circuit shown in FIG. 4 demonstrating a current path within the matrix resulting from an omitted rectifying device;FIG. 6 is a circuit diagram demonstrating a control circuit for an emitter switched array of quasi-resonant inverters comprising switching devices arranged in series;FIG. 7 is a circuit diagram demonstrating a control circuit for an emitter switched array of non-under-clamped quasi-resonant inverters comprising switching devices arranged in series;FIG. 8 is a circuit diagram demonstrating a control circuit for an emitter switched array of non-under- clamped quasi-resonant inverters comprising switching devices arranged in series; andFIG. 9 is a block diagram of an induction system comprising a controller configured to control one or more switching signals configured to control one or more quasi-resonant inverters in accordance with the disclosure. DETAILED DESCRIPTION OF EMBODIMENTS For purposes of description herein the terms "upper," "lower," "right," "left," "rear," "front," "vertical," "horizontal," and derivatives thereof shall relate to the device as oriented in FIG. 1. However, it is to be understood that the device may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise. Conventional induction cooktops may comprise a top surface made of glass-ceramic material upon which cooking units are positioned (hereinafter "cooking utensils"). Induction cooktops operate by generating an electromagnetic field in a cooking region on the top surface. The electromagnetic field is generated by inductors comprising coils of copper wire, w