Classifications

• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B6/00—Heating by electric, magnetic or electromagnetic fields
  • H05B6/02—Induction heating
  • H05B6/10—Induction heating apparatus, other than furnaces, for specific applications
  • H05B6/12—Cooking devices
  • H05B6/1209—Cooking devices induction cooking plates or the like and devices to be used in combination with them
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B6/00—Heating by electric, magnetic or electromagnetic fields
  • H05B6/02—Induction heating
  • H05B6/10—Induction heating apparatus, other than furnaces, for specific applications
  • H05B6/12—Cooking devices
  • H05B6/1209—Cooking devices induction cooking plates or the like and devices to be used in combination with them
  • H05B6/1245—Cooking devices induction cooking plates or the like and devices to be used in combination with them with special coil arrangements
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B6/00—Heating by electric, magnetic or electromagnetic fields
  • H05B6/02—Induction heating
  • H05B6/06—Control, e.g. of temperature, of power
  • H05B6/062—Control, e.g. of temperature, of power for cooking plates or the like
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
  • Y02B40/00—Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers

Definitions

• the present invention relates to an induction cooking or heating apparatus and a method of controlling an induction coil of such an apparatus.
• Induction cooking heats a cooking vessel by magnetic induction instead of by thermal conduction from a flame, or an electrical heating element.
• the cooking vessel may be made of, or contain, a ferromagnetic metal such as cast iron or stainless steel.
• An induction cooker comprising a coil of copper wire is placed under the cooking vessel and an alternating electric current is passed through the coil.
• the resulting oscillating magnetic field induces a magnetic flux which repeatedly magnetises the ferromagnetic metal of the vessel. This produces large eddy currents in the vessel which because of resistance heats the vessel directly. Because inductive heating directly heats the vessel very rapid increases in temperature can be achieved.
• a ferromagnetic plate can be used between the coil and a non-ferromagnetic vessel to act like a hot plate.
• an induction cradle for supporting a cooking vessel to be heated by magnetic induction, the cradle comprising a base member that in use supports a cooking vessel, a first induction coil provided with the base member for producing a first magnetic field having a first field direction, at least a first side member extending orthogonal to the base member and which in use is adjacent a side of a cooking vessel supported in the bases member, and a second induction coil provided with the first side member for producing a second magnetic field having a second field direction, wherein the second field direction is orthogonal to the first field direction, and wherein the first induction coil and second induction coil are wound in series.
• an electrical cooking or heating apparatus comprising an energy conversion module arranged to convert an electrical energy to heat; and a control module arranged to control the conversion of the electrical energy by the energy conversion module; wherein the control module is further arranged to protect the energy conversion module and/or the control module from being damaged by an additional energy supplied to the energy conversion module
• a contact grill having upper and lower heated platens pivotally connected along one adjacent edges and adapted to in use be in contact with respective upper and lower sides of food being cooked, wherein the upper and lower heated platens are heated by induction heating means and wherein a phase of a first magnetic flux generated by the upper heated platen is different from a phase of a second magnetic flux generated by the lower heated platen
• Figure 1 is a perspective view of a first embodiment of an induction cradle according to the invention
• Figure 2 is a front view of the induction cradle
• Figure 3 is a side view of the induction cradle (the other side being more or less the same)
• Figure 4 is a top view of the induction cradle
• Figure 5 is a bottom view of the induction cradle
• Figure 6 is a section view through the induction cradle
• Figure 7 is the induction cradle in combination with one embodiment of a cooking vessel
• Figure 8 is a perspective view of a first embodiment of a cooking vessel according to the invention.
• FIG 9 is a section view through the cooking vessel of Figure 8
• Figure 10 is an exploded view of the cooking vessel of Figure 8
• Figure 11 is an exploded view of a second embodiment of a cooking vessel according to the invention.
• Figure 12 is a perspective view of a second embodiment of an induction cradle according to the invention.
• Figure 13 is the induction cradle of Figure 12 in combination with one embodiment of a cooking vessel
• Figure 14 is a perspective view of a third embodiment of a cooking vessel according to the invention.
• FIG. 15 is an illustration of other embodiments of cooking vessels for use with an induction cradle according to the invention.
• Figure 16 is a block diagram showing control of an induction coil
• Figures 17-20 illustrate a second embodiment of a winding two or three coils according to the invention
• FIG. 21 is a block diagram showing an electrical heating apparatus in accordance with an embodiment of the present invention.
• Figure 22 is an illustration showing two adjacent electrical heating apparatus of Figure 21 .
• Figure 23 is a block diagram showing a first configuration of the electrical heating apparatus of Figure 21 .
• Figure 24 is a plot showing a waveform of a voltage signal across the energy conversion module of the electrical heating apparatus of Figure 23 influenced by an adjacent magnetic flux
• Figure 25 is a block diagram showing a second configuration of the electrical heating apparatus of Figure 21 .
• Figure 26 is a plot showing a waveform of a current signal through the energy conversion module of the electrical heating apparatus of Figure 25 influenced by an adjacent magnetic flux,
• Figure 27 is a block diagram showing a third configuration of the electrical heating apparatus of Figure 21 .
• Figure 28 illustrates a contact grill having upper and lower heated platens pivotally connected and adapted to, in use, be in contact with respective upper and lower sides of food being cooked.
• an induction cradle 10 for supporting a cooking vessel 80 made of, or containing, a ferromagnetic metal such as cast iron or stainless steel to be directly heated by magnetic induction.
• the cradle 10 comprises a base 11 with feet 12 for supporting the base of a work surface, and a top 13 that in use supports a cooking vessel.
• the top 13 may be made of a suitable non- ferromagnetic material such as glass or ceramic.
• first and second side members 14, 15 Extending upwardly from adjacent sides of the base 11 , and orthogonally to the base 1 1 , are first and second side members 14, 15.
• the second side member 15 extend from a second side of the base 1 1 opposite the first side member 14 such that the first and second side members 14, 15 define between them an induction cooking space 16 above the base 11.
• Positioning members 19 in the form of posts extending inwardly from respective sides 14, 15 facilitate central location of a cooking vessel on the cook top 13 centrally between the sides 14, 15.
• the positioning members 19 are preferably but not essential features of the invention. In some embodiments the positioning members 19 may be optionally removable for use with some cooking vessels but not others, and/or the positioning members 19 may be adjustable in length and or position to accommodate different types of cooking vessel.
• a first induction coil 30 is provided with the base member for producing a first magnetic field having a first field direction orthogonal to the base 11.
• An alternating electric current is passed through the first coil 30 resulting in a first oscillating magnetic field that induces a magnetic flux in a cooking vessel supported on the plate 13.
• a second induction coil 31 is located in the first side member 14 and, upon passing an alternating electric current through the second coil 31 , produces a second magnetic field having a second field direction parallel to the base 11.
• the second field direction is orthogonal to the first field direction.
• a third induction coil 32 is located in the second side member 15 and, upon passing an alternating electric current through the second coil 32, produces a third magnetic field having a third field direction parallel to the base 11.
• the third field direction is orthogonal to the first field direction.
• the third field direction is parallel and opposite to the second field direction.
• the second and third inductions coils may be enclosed in coil enclosures 17, 18 of respective sides 14, 15.
• the coil enclosures 17, 18 may be made of a suitable non-ferromagnetic material with a surface such as glass or ceramic.
• Figure 12 is a block diagram illustrating a control system for one of the induction coils 30.
• the control of second and third induction coils 31 , 32 is the same.
• the induction coil 30 is arranged to convert electrical energy (i.e. an alternating electrical current) to magnetic energy (i.e. an oscillating magnetic field).
• Electrical energy is supplied to the induction cradle 10 via a power cord 21 which has a standard domestic plug (not shown) at its distal end for connection with a domestic alternating current (AC) power supply.
• AC domestic alternating current
• the induction cradle may alternatively be supplied with electrical energy from a portable direct current (DC) source such as an external automotive or other battery, or an internal rechargeable battery.
• DC portable direct current
• a control module 104 arranged to control the conversion of the electrical energy by the coil 30.
• the control module 104 is further arranged to protect the coil and/or the control module 104 from being damaged by an additional energy supplied to the coil, by for example an additional electromotive force (emf) induced in the first coil by a proximate or adjacent varying magnetic fields of adjacent coils 31 , 32.
• emf additional electromotive force
• the control module 104 may comprise various components arranged to convert an input power delivered to the induction cradle 10 to an electrical energy in a suitable form so as to precisely control the output of the induction coil 30, and hence control the temperature and/or the heating pattern of a cooking vessel.
• the control module 104 may comprise a converter arranged to convert the input power to an alternating current which may be further fed to the induction coil 30 such that a repeatedly varying magnetic flux will be generated.
• the control module 104 may also include a microcontroller or a microprocessor for controlling the different electrical/electronic components of the cradle 10 to operate appropriately as desired.
• the controller 104 may include or connect to different sensors and/or detectors so as to monitor the operations and/or the conditions of the cradle 10 or cooking vessel, and to protect the cradle from various improper operations such as improper power supply, improper cookware, and other improper working condition such as overheating and high humidity.
• the control module 104 may further comprise a decision module 108 for use in a protection mechanism.
• the control module may also comprise a driver module 1 10 arranged to drive the induction coil 30.
• a detection module 1 12 connected to both the induction coil 30 and the control module 104.
• a control interface 22 is provided on one of the side panels 14, 15 for receiving user inputs via input controls 23, 24 to control conversion of electrical energy to magnetic energy.
• the input controls 23, 24 are mounted to a printed circuit board (PCB) 26 with the control interface 22 and in the side member.
• PCB printed circuit board
• Inputs controls may include controls for one or more of on/off, cooking (e.g. energy conversion) power, cooking mode (such as use of one or more inductions coils 30, 31 , 32), cooking time or cooking programs.
• a digital or other display 25 is provided on the control interface 22 for indicating one or more control or cooking parameters to the user.
• the control module 104, decision module 108 and a driver module 110 for each induction coil may also be mounted with the PCB 26.
• FIG 7 illustrates an induction cooker comprising the induction cradle 10 in combination with a cooking vessel 80 made of, or containing, a ferromagnetic metal such as cast iron or stainless steel.
• the vessel 80 comprises a pot portion 83 and a lid portion 81 with a handle 82.
• the base portion 83 of the vessel 80 includes a ferromagnetic metal base portion 84 which rests on the base top 13 and is heated by the first induction coil 30.
• Figures 8 and 9 illustrate a first embodiment of a cooking vessel 80 according to the invention.
• the lid portion 81 of the vessel is provided with a ferromagnetic metal lid portion 90 which is indirectly heated by convection from the vessel base 83.
• Diametrically opposite portions of the side walls 94 of the vessel base 83 are made of, or contain, a ferromagnetic metal such as cast iron or stainless steel such that the side walls are directly heated by the second and third induction coils 31 , 32 in the sides 14, 15 of the cooking cradle 10.
• the upper circumferential lip of the vessel base 83 is provided with a heat transfer flange 92 made from a thermally conductive and also preferably ferromagnetic metal which is heated both directly by the second and third induction coils 31 , 32 and indirectly via convention from the diametrically opposite portions of the side walls 94.
• the ferromagnetic metal lid portion 90 comprises a plate 97 shaped to follow the profile of the lid 81.
• Securing tabs 99 secure the ferromagnetic metal lid portion 90 within the underside of the lid 81.
• the heat transfer tabs 98 are in thermally conductive contact with the heat transfer flange 92 of the base 83 to transfer heating to the lid portion 90 by convection heating. It is to be understood that the ferromagnetic metal lid portion 90 may also be heated directly by one or more of the oscillating magnetic fields as well as receiving conduction heating from the heat transfer flange 92.
• the vessel 80 is heated in its base 84, sidewalls and lid 81 , 90 by the oscillating magnetic fields and by convention to surround the food items(s) in the vessel 80 by heated portions of the vessel which heat the from items from top and sides by radiant heat transfer as well as convective heat transfer. Cooking with radiant heat transfer from the sides and the top provides an overall browning effect on meat items (such as fish, poultry and red meat for example) as well and more event internal cooking of all food items.
• meat items such as fish, poultry and red meat for example
• FIG. 1 1 is an exploded view of a second embodiment of a cooking vessel according to the invention.
• the cooking vessel 80 is made of, or contains, a ferromagnetic metal such as cast iron or stainless steel.
• the vessel 80 comprises a pot portion 83 and a lid portion 81 with a handle 82.
• the base portion 83 of the vessel 80 includes a ferromagnetic metal base portion 84 which rests on the base top 13 and is heated by the first induction coil 30.
• the lid portion 81 of the vessel is provided with a ferromagnetic metal lid portion 88 which is directly heated by the second and third induction coils 31 , 32 in the sides 14, 15 of the cooking cradle 10.
• the ferromagnetic metal lid portion 88 comprises a plate 87 shaped to follow the profile of the lid 81.
• a pair of securing studs 89 accommodates bolts to secure the ferromagnetic metal lid portion 88 within the underside of the lid 81.
• a pair of ferromagnetic metal orthogonal side wings 85, 86 are arranged in use to be positioned immediately in from respective second and third induction coils 31 , 32 in the sides 14, 15 of the cooking cradle 10. The wings preferably extend outside of the pot portion 83 when the lid 81 is in place and are directly heated by the second and third induction coils 31 , 32.
• the wings 85, 86 are in thermally conductive contact with the ferromagnetic metal lid portion 88 to transfer heating to the lid portion 88 by convection heating. It is to be understood that the ferromagnetic metal lid portion 88 may also be heated directly by one or more of the oscillating magnetic fields as well as receiving conduction heating from the orthogonal side wings 85, 86.
• Figures 12 and 13 illustrate a second embodiment of an induction cooking cradle according to the invention, which is substantially the same as the embodiment described above, but which has only a second induction coil located in the single side member, thus relying to a greater extent on convective heat transfer round the rides of the vessel base to heat all sides.
• Such an embodiment is simpler and cheaper to manufacture and provides many of the convective and radiant heating benefits in the upper and top of the cooking vessel provide by both second and third induction coils 31 , 32 of the induction cradle of Figure 1.
• Figure 14 illustrates yet a further embodiment of a cooking vessel for use with the invention.
• a non- ferromagnetic metal vessel such as a glass or ceramic vessel 102 is provided with a removable ferromagnetic metal cooking plate 103 which positions in the vessel to be heated by the associating magnetic fields.
• the ferromagnetic metal cooking plate 103 comprises a base portion 104 and a side portion 105 extending substantially orthogonal to the base portion 104.
• the base portion is heated by the base induction coil and the side portion is heated by the second induction coil.
• Such an embodiment of the vessel in combination with the ferromagnetic metal cooking plate 103 is simpler and cheaper to manufacture and provides many of the convective and radiant heating benefits in the upper and top of the cooking vessel provide by both second and third induction coils 31 , 32 of the induction cradle of Figure 1.
• the ferromagnetic metal cooking plate 103 can be sold or provided for use in conventional non-ferromagnetic metal vessel so that such vessels may be used with an induction cooking cradle of the invention.
• a metal cooking plate 103 can be provided with an induction cradle so that users can use their current non-ferromagnetic cookware with the induction cradle.
• the cooking vessel may be one of a roasting dish, a rotisserie, a deep fryer, a steamer, a soup maker, a pizza maker, an oven, a roasting drum, a grill or a pot.
• the cooking vessels of the invention do not have any electrical components and thus are easily cleaned by submersion in water or a dishwasher.
• a combination of the induction cradle 10 and two or more of such cooking vessels provides a useful and versatile induction cooking system.
• the second and thirds induction coils in combination with a cooking vessel having upper ferromagnetic metal heating portions provides more even hearing within the cooking vessel resulting in more even cooking and browning of food items.
• Such an arrangement of the invention may also be used to provide an oil-less deep fryer cooking chamber.
• each coil 30, 31 , 32 is individual and has its own control module 104, decision module 108 and a driver module 1 10 mounted on a common or separate PCBs.
• all coils are wound in series so as to be operable from a single control module 104, decision module 108 and a driver module 110 set.
• Figures 17 through 20 illustrate the coil arrangement for such an embodiment. All three (or two as the case may be) induction coils 30, 31 and 32 are would as a single series electrical circuit.
• Figures 19 and 20 illustrate alternative winding arrangements for series coils. Only two turns are shown for each coil for clarity. In the winding arrangement of Figure 19 each turn of the three coils is would consecutively with a turn of an adjacent coil.
• Figure 18 illustrates a method of winding all three coils in series.
• a coils former is provided in a plat plan which can be easily wound by hand of an automated winding machine. After winding the wings of the former can be folded or bend through 90-degrees about reference lines A-A and B-B for example such that at least two coils having orthogonal to the field directions.
• an electrical heating apparatus 1100 comprising an energy conversion module (e.g. a coil) 1102 arranged to convert electrical energy to magnetic energy; and a control module 1 104 arranged to control the conversion of the electrical energy by the energy conversion module 1102.
• the control module 1104 is further arranged to protect the energy conversion module 1102 and/or the control module 1104 from being damaged by an additional energy supplied to the energy conversion module 1102, by for example an additional electromotive force (emf) induced in the energy conversion module 1102 by a proximate or adjacent varying magnetic field.
• emf additional electromotive force
• the electrical heating apparatus 1 100 is an induction heater
• the energy conversion module 1102 comprises a metal coil arranged to convert electrical energy to a magnetic flux.
• a metal coil arranged to convert electrical energy to a magnetic flux.
• the magnetic flux may then be transmitted (coupled) to a metallic component 1106 such as a ferrous plate or cookware, inducing an electric current in the metallic component 1106 causing the metallic component 1 106 to heat up.
• a metallic component 1106 such as a ferrous plate or cookware
• the metallic component 1 106 consists of a ferromagnetic metal such as cast iron or stainless steel, and is arranged to repeatedly produce eddy currents within the metallic component 1 106 in response to a repeatedly varying magnetic flux generated by the adjacent metal coil 1 102. Due to the electrical resistance of the ferromagnetic metal, the metallic component 1 106 is heated by joule heating.
• the control module 1 104 may comprise various components arranged to convert an input power delivered to the induction heater 1 100 to an electrical energy in a suitable form so as to precisely control the output of the energy conversion module 1 102, and hence control the temperature and/or the heating pattern of the induction heater 1 100.
• the control module 1 104 may comprise a converter arranged to convert the input power to an alternating current which may be further fed to the metal coil 1 102 such that a repeatedly varying magnetic flux will be generated.
• the control module 1 104 may also include a microcontroller or a microprocessor for controlling the different electrical/electronic components of the induction heater 1 100 so that the heater 1 100 may operate appropriately as desired.
• controller 1 104 may include or connect to different sensors and/or detectors so as to monitor the operations and/or the conditions of the heater 1 100, and to protect the heater 1 100 from various improper operations such as improper power supply, improper cookware, and other improper working condition such as overheating and high humidity.
• control module 1 104 may further comprise a decision module 1 108 for use in a protection mechanism.
• the control module may also comprise a driver module 1 1 10 arranged to drive the metal coil 1 102.
• a detection module 1 1 12 connected to both the metal coil 1 102 and the control module 1 104.
• the energy conversion module 1 102 of the first induction heater 1 100 is near an approximate energy conversion module 1202 of the second induction heater 1200.
• Such an arrangement is used, for example, in a contact grill where food items are located between upper and lower grill platens (grill plates) and in contact with both the upper and lower grill platens for cooking both sides of the food simultaneously.
• the magnetic flux generated by the proximate second energy conversion module 1202 of the operating second induction heater 1200 may induced an emf in the first energy conversion module 1 102 of the first induction heater 1 100 and visa-versa.
• Such induced additional emf in the energy conversion module 1 102, 1202 contributes an additional voltage and/or an additional current supplied to the energy conversion modules 1 102, 1202.
• the first induction heater 1 102 is also operating at the same time, such additional energy supplied by the proximate energy conversion module 1202 to the energy conversion module 1 102 will superimpose to the original energy generated by the first energy conversion module 1 102 in which the total amount of energy may exceed the rated limit of the first energy conversion module 1 102.
• the voltage across the energy conversion module 1 102 and/or the connected first control module 1 104 is unexpectedly high, or the current passing through the first energy conversion module 1 102 and/or the connected control module 1 104 may exceed the working limit of the modules, and may cause damages to the energy conversion module 1 102 and/or the control module 1 104.
• the control module 1 104 is arranged to prevent a voltage and/or a current exceeding a rated limit of the control module 1 104 and/or the energy conversion module 1 102 from being supplied to the control module 1 104 and/or the energy conversion module 1 102.
• the electrical heating apparatus 1 100 fur comprises a detection module 1 12 arranged to detect a voltage and/or a current supplied to the energy conversion module 1 102.
• the detection module 1 1 12 comprises a voltage detection device 1302, and the voltage detection device 1302 is coupled across the energy conversion module or the energy conversion coil 1 102 such that the voltage across the energy conversion coil 1 102 may be detected by the voltage detection device 1302.
• the control module 1 104 further comprises a decision module 1 108 connected to the voltage detection device 1302. The decision module 1 108 may process the real-time voltage value provided by the voltage detection device 1302, and accordingly controls the conversion of the electrical energy to heat by the energy conversion module 1 102 based on the detection of the supplied voltage.
• the control module 1 104 may utilize the decision module 1 108, and may be arranged to shut down or suspend the driver module 1 1 10 (which may include the driving inverter 1304 and the IGBT driver 1306) arranged to drive the energy conversion module 1 102, and hence the conversion of the electrical energy by the energy conversion module 1 102 is suspended. It is shown in Figure 24 an example waveform of the voltage level across the energy conversion coil 1 102 measured by the voltage detection device 1302.
• the detection module 1 1 12 comprises a current detection device 1308, and the current detection device 1308 is arranged to detect the current passing thru the energy conversion module 1 102.
• the current detection device 1308 is coupled to a current transformer 31 10 such that the current measured by the current detection device 1308 represents an actual real-time current signal passing through the energy conversion module 1 102 associated with a predetermined ratio.
• the current detection mechanism may be implemented in any other configuration as known by a person skilled in the art.
• control module 1 104 further comprises a decision module 1 108 connected to the current detection device 1308.
• the decision module 1 108 may process the realtime current value provided by the current detection device 1308, and accordingly controls the conversion of the electrical energy to heat by the energy conversion module 1 102 based on the detection of the supplied current. For example, whereupon a detection of a current supplied the energy conversion module 1 102 exceeding a predetermined limit, the control module 1 104 may utilize the decision module 1 108, and may be arranged to shut down or suspend the driver module 1 1 10 (which may include the driving inverter 1304 and the IGBT driver 1306) arranged to drive the energy conversion module 1 102, and hence the conversion of the electrical energy by the energy conversion module 1 102 is suspended. It is shown in Figure 26 an example waveform of the current level across the energy conversion coil 1 102 measured by the current detection device 1308.
• control module 1 104 may be arranged to employ a tactic to attempt to drive the energy conversion module 1 102 at a time of no superimposition of the additional energy is detected.
• the predetermined limit may be a safe or maximum operating limit of the voltage and/or current supplied to the energy conversion module 1 102 or the metal coil.
• the predetermined limit may represent a normal operation parameter of the electrical heating apparatus 1100, such as a rated operating voltage and/or current supplied to the energy conversion module 1 102.
• both the energy conversion module 1 102 as well as the connected control module 1 104 may be protected from being damaged by the additional energy induced by the energy conversion module 1 102.
• the detection module 1 1 12 may be arranged to detect an existence of an additional magnetic flux. The detection is based on the measured waveform obtained from the voltage and/or the current detection device. In general, it is unlikely that two magnetic fluxes generated by two induction heater will include an identical working frequency and phase, and a beat frequency condition (as shown in the waveforms in Figures 24 and 26) occurs when two electrical signals with different frequency and phase superimpose. Thus, a beat frequency condition in a measured voltage and/or current waveform indicates the existence of an additional magnetic flux. In addition, the intensity of the additional magnetic flux re represented by an amplitude of the beat frequency condition.
• the decision module 1 108 may also be arranged to control the energy conversion module 1 102 in response to the detection of the additional magnetic flux based on the measured beat frequency condition.
• one or other of the first and/or second control modules may be arranged to vary the phase of the alternating voltage or current to the respective first or second energy conversion module thereby phase shifting the resultant magnetic flux so as to maintain the total of the control power plus induced emf/current of the adjacent energy conversion module within predetermined limits. That is to say, by controlling the phase of the supply signals and resultant magnetic flux of the respective energy conversion modules the effect of magnetic coupling between the two energy conversion modules can be ameliorated.
• the electrical heating apparatus 1 100 comprises a voltage detection device 1302 and a current detection device 1308 both coupled to the decision module 1108, such that the control module 1104 is arranged to control the energy conversion module 1102 based on both the measured voltage and current value obtained by the detection module 1112.
• the electrical heating apparatus 1100 comprises other essential components such as temperature sensors 1702, power supply monitors 1704, EMC filters 1706, rectifiers and filters 1708, and a microcontroller 1710.
• the microcontroller 1710 may be coupled to user operation panels and display for receiving user input and providing displayed information to the user.
• the microcontroller 1710 may be arranged to monitor and/or control the operation environment of the electrical heating apparatus.
• the microcontroller may be arranged to control the heating pattern based on different pre-set programs.
• an energy conversion module such as an induction coil as well as the connected controller or drivers are well protected from additional or external magnetic flux supplied to the induction heater or the metal coil in the induction heater, such that multiple induction heating elements may be included in a single electrical heating apparatus.
• the manufacturers may not necessary to consider the alignment or misalignment of the different metal coils.
• an electrical heating apparatus 1300 may comprise both an energy conversion module 1 102 as well as the proximate energy conversion module 1202.
• Such electrical heating apparatus 1200 with dual induction heaters (1200 and 1100) at the top and the bottom may be employed to provide more flexible cooking technique.
• Figure 28 Illustrates a contact grill having upper and lower heated platens 1800 and 1801 pivotally connected and adapted to, in use, be in contact with respective upper and lower sides of food being cooked.
• the upper and lower heated platens are heated by induction heating means as herein described.

Landscapes

• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Induction Heating Cooking Devices (AREA)
• General Induction Heating (AREA)

Priority Applications (2)

Applications Claiming Priority (6)

Publications (1)

Family

ID=57248944

Family Applications (1)

Country Status (3)

Cited By (3)

Families Citing this family (2)

Citations (11)

• 2016
  • 2016-05-09 KR KR1020177035365A patent/KR20180025857A/ko unknown
  • 2016-05-09 WO PCT/IB2016/000609 patent/WO2016181208A1/en active Application Filing
  • 2016-05-09 CN CN201680040338.7A patent/CN107950075A/zh active Pending

Patent Citations (11)

Also Published As

Similar Documents

Legal Events