Induction heating apparatus and induction heating method

Abstract

To obtain an induction heating device with improved convenience. [Solution] The system comprises an inverter unit having a first inverter and a second inverter, a heating unit having a first heating coil continuously driven by the first inverter and a second heating coil continuously driven by the second inverter, a control unit for controlling the inverter unit, and a notification unit that notifies the user of information regarding a first maximum power, which is the maximum power that the first inverter can output, when an object to be heated is placed on a position heated by the first heating coil and a position heated by the second heating coil, respectively. The first maximum power is the smaller of the value obtained by subtracting the output power of the second inverter from the maximum power that the inverter unit can output, and the value of a first characteristic power of the object to be heated, which is determined from the characteristics of the object placed on the position heated by the first heating coil.

Description

Technical Field

[0001] The present disclosure relates to an induction heating device and an induction heating method.

Background Art

[0002] Conventionally, there is an induction heating cooker that drives a plurality of heating coils. In Patent Document 1, in an induction heating cooker in which a plurality of heating coils are connected to one main power circuit and these heating coils are switched to be driven for heating, the first maximum heating power when only one heating coil is driven is compared with the second maximum heating power of each heating coil when a plurality of heating coils are driven. [Second maximum heating power = First maximum heating power ÷ Number of heating coils], and an induction heating cooker that displays the set maximum heating power is described.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the induction heating cooker described in Patent Document 1, the maximum heating power is determined only from the number of heating coils being driven. Therefore, in the induction heating cooker described in Patent Document 1, there is a problem that the user cannot obtain the maximum heating power considering the heating efficiency of the object to be heated by the heating coils, resulting in low convenience.

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to improve the convenience of an induction heating device.

Means for Solving the Problems

[0006] The induction heating device according to this disclosure comprises a first inverter, an inverter unit having a second inverter, a heating unit having a first heating coil continuously driven by the first inverter, a second heating coil continuously driven by the second inverter, a control unit for controlling the inverter unit, and a notification unit that notifies the user of information regarding a first maximum power, which is the maximum power that the first inverter can output, when an object to be heated is placed on a position heated by the first heating coil and a position heated by the second heating coil, respectively. The first maximum power is the smaller of the value obtained by subtracting the output power of the second inverter from the maximum power that the inverter unit can output, and the value of a first characteristic power of the object to be heated, which is determined from the characteristics of the object placed on the position heated by the first heating coil.

[0007] Furthermore, the induction heating method according to the present disclosure is an induction heating device having a first inverter, an inverter unit having a second inverter, a first heating coil continuously driven by the first inverter, a second heating coil continuously driven by the second inverter, a control unit for controlling the inverter unit, and a notification unit for notifying information regarding a first maximum power, which is the maximum power that the first inverter can output, when an object to be heated is placed on a position heated by the first heating coil and a position heated by the second heating coil, respectively, wherein the control unit includes the step of setting the first maximum power to the smaller of the value obtained by subtracting the output power of the first inverter from the value of power that the inverter unit can output, and the value of a first characteristic power of the object to be heated, which is determined from the characteristics of the object to be heated placed on the position heated by the first heating coil. [Effects of the Invention]

[0008] The induction heating apparatus and induction heating method described herein have the effect of improving the convenience of the induction heating apparatus. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing the configuration of an induction heating device according to Embodiment 1 of the present disclosure. [Figure 2] This is a block diagram showing the functional configuration of the control device for an induction heating device according to Embodiment 1 of the present disclosure. [Figure 3] This is a block diagram showing the hardware configuration of the control device for an induction heating device according to Embodiment 1 of the present disclosure. [Figure 4] This flowchart shows the processing content of the control device for the induction heating apparatus according to Embodiment 1 of this disclosure. [Figure 5] This flowchart shows the processing details for determining the first maximum heat output performed by the control device of the induction heating apparatus according to Embodiment 1 of this disclosure. [Figure 6] This figure shows the notification content of the notification device for the induction heating device according to Embodiment 1 of this disclosure. [Figure 7] This figure shows the notification content in the notification device of the induction heating device according to Embodiment 2 of this disclosure when the first maximum power is differential power. [Figure 8] This figure shows the notification content in the notification device of the induction heating device according to Embodiment 2 of the present disclosure when the first maximum power is the first characteristic power of the heated object. [Modes for carrying out the invention]

[0010] Embodiments of this disclosure will be described below with reference to the drawings. However, this disclosure is not limited to the embodiments described below, and modifications or omissions are permitted without departing from the spirit of this disclosure. Furthermore, common elements in each drawing are denoted by the same reference numerals, and redundant explanations are omitted.

[0011] Embodiment 1. Figure 1 is a schematic diagram showing the configuration of an induction heating device 1 according to Embodiment 1 of this disclosure. The general outline of the induction heating device 1 will be explained using Figure 1. In addition, the AC power supply 10 and the object to be heated 16 shown in Figure 1 are included for illustrative purposes only and are not included as components of the induction heating device 1.

[0012] As shown in Figure 1, the induction heating device 1 comprises a rectifier circuit 11, a filter 12, an inverter unit 13, a resonant capacitor 14, a heating unit 15, a detection device 17, a control device 18, a notification device 19, and an operating device 20.

[0013] Furthermore, the induction heating device 1 can use cooking utensils such as pots made of magnetic metals and cooking utensils such as pots made of non-magnetic metals as objects to be heated. Examples of magnetic metals include iron or stainless steel. Examples of non-magnetic metals include aluminum or copper.

[0014] The rectifier circuit 11 is connected to the AC power supply 10. The AC power supply 10 is, for example, a commercial power supply. The rectifier circuit 11 converts the AC voltage output by the AC power supply 10 into a DC voltage. Note that the rectifier circuit does not have to be connected to an AC power supply. For example, it could be connected to a DC power supply or a power converter.

[0015] The filter 12 is provided between the rectifier circuit 11 and the inverter section 13, and removes noise generated from the inverter section 13. Specifically, the filter 12 is an LC filter. However, a passive filter with a different configuration than an LC filter may be used as the filter. Alternatively, an active filter using active elements may be used as the filter.

[0016] The inverter unit 13 converts a DC voltage into a high-frequency voltage of several tens of kHz and outputs it. The inverter unit 13 uses a half-bridge inverter circuit composed of two switching elements. However, the circuit configuration is not limited to this, and any circuit configuration capable of generating a high-frequency voltage is acceptable. For example, it may be a full-bridge inverter circuit composed of four switching elements, or a single-ended inverter circuit using a single switching element.

[0017] The inverter unit 13 includes a first inverter 13a and a second inverter 13b. The first inverter 13a and the second inverter 13b are predefined according to the location. The first inverter 13a passes a high-frequency current through the first resonance capacitor 14a and the first heating coil 15a. Also, the second inverter 13b passes a high-frequency current through the second resonance capacitor 14b and the second heating coil 15b.

[0018] A high-frequency voltage converted by the inverter unit 13 is applied to the resonance capacitor 14 and the heating unit 15. The resonance capacitor 14 and the heating unit 15 are resonance loads through which a high-frequency current flows in response to the output voltage of the inverter, and are connected in series to the output terminals of the inverter 13 respectively.

[0019] The resonance capacitor 14 has a first resonance capacitor 14a and a second resonance capacitor 14b. The heating unit 15 has a first heating coil 15a and a second heating coil 15b. The first heating coil 15a is continuously driven by the first inverter 13a. Also, the second heating coil 15b is continuously driven by the second inverter 13b.

[0020] In this specification, continuous driving represents a method of continuously operating, different from intermittent driving that stops at regular intervals. When performing continuous driving, the first inverter and the second inverter may be driven simultaneously, and the power output at all times needs to be below the limited power, which is the maximum power that the inverter unit 13 can output.

[0021] The heating unit 15 heats the object to be heated 16. The object to be heated 16 is a cooking container that is placed in a position to be heated by the heating unit 15 and heated by the principle of electromagnetic induction. In Embodiment 1, the position heated by the heating unit 15 is on top of the heating unit 15. More specifically, the positions heated by the heating unit 15 are on top of the first heating coil 15a and on top of the second heating coil 15b. In Embodiment 1, the object to be heated 16 comprises a first object to be heated 16a placed on top of the first heating coil 15a and a second object to be heated 16b placed on top of the second heating coil 15b. When eddy currents flow through the object to be heated 16 due to electromagnetic induction, Joule heat is generated in the object to be heated 16, and the object to be heated 16 is heated. The material of the object to be heated 16 may be a magnetic metal or a non-magnetic metal.

[0022] The detection device 17 detects the voltage output by the inverter unit 13 and the current flowing through the heating unit 15 at regular intervals. Specifically, the detection device 17 includes a voltage detection unit 171 that detects the voltage output by the inverter unit 13 and a current detection unit 172 that detects the current flowing through the heating unit 15. The detection device 17 transmits signals indicating the detected voltage output by the inverter unit 13 and the current flowing through the heating unit 15 to the control device 19.

[0023] The voltage detection unit 171 includes a first voltage detection unit 171a and a second voltage detection unit 171b. The first voltage detection unit 171a detects a first voltage, which is the voltage output by the first inverter 13a. The second voltage detection unit 171b detects a second voltage, which is the voltage output by the second inverter 13b.

[0024] The current detection unit 172 has a first current detection unit 172a and a second current detection unit 172b. The first current detection unit 172a detects the first current, which is the current flowing through the first heating coil 15a. The second current detection unit 172b detects the second current, which is the current flowing through the second heating coil 15b.

[0025] The control device 18 controls the drive of the inverter unit 13. Specifically, when the control device 18 determines that the first object to be heated 16a is placed on the first heating coil 15a and the second object to be heated 16b is placed on the second heating coil 15b, it controls the power output of the first inverter 13a so that it is less than or equal to the first maximum power. The first maximum power is the smaller of the following two values: the value obtained by subtracting the power output of the second inverter 13b from the limiting power value, which is the maximum power that the inverter unit 13 can output, and the value of the first characteristic power of the object to be heated, which is determined from the characteristics of the first object to be heated 16a. Details of the first characteristic power of the object to be heated will be described later.

[0026] The first object to be heated 16a is either a magnetic or non-magnetic metal. Heating a non-magnetic metal with an induction heating device results in greater losses and lower heating efficiency than heating a magnetic metal. Therefore, if the first object to be heated 16a is a non-magnetic metal, components such as parts of the first inverter 13a may overheat. To prevent this, if the control device 18 determines that the first object to be heated 16a is a non-magnetic metal, it reduces the first maximum power to a lower value than if the first object to be heated 16a were determined to be a magnetic metal. Since magnetic metals usually have higher resistance than non-magnetic metals, if the resistance of the first object to be heated 16a is greater than a predetermined first resistance threshold, the first characteristic power of the first object to be heated is increased to a higher value than if the resistance of the first object to be heated 16a is less than the first resistance threshold. In other words, in Embodiment 1, the characteristic power of the first heated object is a value that changes depending on whether the first heated object 16a is a magnetic metal or a non-magnetic metal.

[0027] Furthermore, the control device 18 determines the first maximum thermal power and transmits information indicating the first maximum thermal power to the notification device 19, which will be described later. The first maximum thermal power is the thermal power corresponding to the first maximum power and is an indicator of the outputtable thermal power. The magnitude of the thermal power is indicated in multiple stages at the first maximum thermal power. The specific configuration of the control device 18 will be described later.

[0028] This configuration allows the induction heating device 1 to determine the first maximum heat output by considering the heating status of the heating section 15 and the heating efficiency of the object being heated, thereby improving the convenience of the induction heating device 1.

[0029] Furthermore, the control device 18 accepts operations received from the operating device 20, which will be described later. The control device 18 does not accept the operation if it determines that executing the operation received from the operating device 20 would cause the power output of the first inverter 13a to exceed the value of the first maximum power. The control device 18 corresponds to the control unit that controls the inverter unit 13.

[0030] Furthermore, if the control device 20 does not accept input, the notification device 19 may be configured to notify the user that the input has not been accepted. This configuration improves the operability of the induction heating device 1.

[0031] The notification device 19 notifies the user of the first maximum heating power. The notification device 19 is, for example, a display. The notification device 19 also displays to the user the heating power currently output by the first inverter 13a in stages. Furthermore, the notification device 19 is a notification unit that notifies the user of the first maximum power, which is the maximum power that the first inverter 13a can output, when the object to be heated 16 is placed at the position heated by the first heating coil 15a and the position heated by the second heating coil 15b, respectively. The specific display content of the notification device 19 will be described later.

[0032] The operating device 20 is a device operated by the user, such as an operating button. Specifically, the operating device 20 is used by the user to turn the power on, turn it off, and adjust the heat output. The operating device 20 corresponds to the operating section operated by the user.

[0033] Figure 2 is a block diagram showing the functional configuration of the control device 18 of the induction heating device 1 according to Embodiment 1 of this disclosure. Figure 3 is a block diagram showing the hardware configuration of the control device 18 of the induction heating device 1 according to Embodiment 1 of this disclosure. The specific configuration of the control device 18 will be described using Figures 2 and 3.

[0034] As shown in Figure 2, the control device 18 includes a transmitting / receiving unit 181, a storage unit 182, a determination unit 183, a placement determination unit 184, and a signal generation unit 185.

[0035] The transmitting / receiving unit 181 transmits signals from or receives signals to the control device 18. The transmitting / receiving unit 181 receives signals from the detection device 17 indicating the voltage output by the inverter unit 13 and the current flowing through the heating unit 15. The transmitting / receiving unit 181 also receives signals from the operating device 20 indicating operations performed by the user. The transmitting / receiving unit 181 also transmits control signals to the first inverter 13a. The transmitting / receiving unit 181 also transmits a signal indicating the first maximum heating power to the notification device 19.

[0036] The memory unit 182 stores information related to the control of the induction heating device 1. Specifically, the memory unit 182 stores information relating the first resistance threshold, the second resistance threshold, the limiting power, the first maximum power, and the first maximum heating power. The second resistance threshold will be described later. The value of the limiting power is set in advance by the rating of the rectifier circuit 11 or the power limit value according to the standard. Also, the larger the first maximum power, the larger the first maximum heating power. In other words, when the first maximum heating power is at level 2, the corresponding first maximum power is larger than when the first maximum heating power is at level 1.

[0037] The determination unit 183 determines the values ​​necessary for controlling the induction heating device 1. Specifically, the determination unit 183 determines the differential power, the first heated object characteristic power, the first maximum power, the first maximum heating power, and the resistance value of the first heated object 16a.

[0038] The determination unit 183 determines the differential power by subtracting the value obtained by subtracting the second power, which is the power consumed by the second inverter, from the limit power value stored in the memory unit 182. The second power is calculated from the voltage value acquired by the second voltage detection unit 171b and the current value acquired by the second current detection unit 172b.

[0039] Furthermore, the determination unit 183 determines the first heated object characteristic power by obtaining a first maximum power corresponding to the resistance value of the first heated object 16a from the storage unit 182. The resistance value of the first heated object 16a is calculated from the voltage value obtained by the first voltage detection unit 171a and the current value obtained by the first current detection unit 172a.

[0040] The placement determination unit 184 determines whether the object to be heated 16 is placed in a position where it will be heated by the inverter unit 13. More specifically, the placement determination unit 184 determines whether the first object to be heated 16a is placed on the first heating coil 15a. The placement determination unit 184 also determines whether the second object to be heated 16b is placed on the second heating coil 15b. The placement determination unit 184 determines that the first object to be heated 16a is placed on the first heating coil 15a if the resistance value of the first object to be heated 16a is equal to or greater than the second resistance threshold stored in the storage unit 182. The placement determination unit 184 also determines that the second object to be heated 16b is placed on the second heating coil 15b if the resistance value of the second object to be heated 16b is equal to or greater than the second resistance threshold. When the object to be heated 16 is placed on the heating coil 15, the generated magnetic field links with the object to be heated 16, thereby generating an induced current. The resistance value of the second object to be heated 16b is calculated from the voltage value acquired by the second voltage detection unit 171b and the current value acquired by the second current detection unit 172b.

[0041] The signal generation unit 185 generates control signals to control the operation of the induction heating device 1. Specifically, the signal generation unit 185 determines the first maximum power. The signal generation unit 185 also generates a signal indicating the notification content of the notification device 19.

[0042] As shown in Figure 3, the hardware configuration of the control device 18 includes a processor 186, memory 187, storage 188, and a hardware interface 189.

[0043] The processor 186 executes the program stored in memory 187. Specifically, the processor 186 determines the first maximum heating power when it determines that the first object to be heated 16a is placed on the first inverter 13a and the second object to be heated 16b is placed on the second inverter 13b. The processor 186 also generates signals to control the operation of the induction heating device 1 and signals indicating the content of the notification from the notification device 19.

[0044] Memory 187 stores the program executed by the processor 186. Memory 187 is also used as a workspace for the processor 186. Memory 187 can be, for example, volatile memory such as RAM (Random Access Memory), non-volatile memory such as ROM (Read Only Memory), or a combination of both. The determination unit 183, the placement determination unit 184, and the signal generation unit 185 are implemented by the processor 186 and memory 187.

[0045] The storage unit 188 stores information relating the first resistance threshold, the second resistance threshold, the limiting power, the first maximum power, and the first maximum thermal power. The memory unit 182 is realized when information is stored in the storage unit 188.

[0046] The hardware interface 189 transmits or receives signals wirelessly or via wired connection with the inverter unit 13, detection device 17, notification device 19, and operating device 20. The transmitting / receiving unit 181 is implemented by the hardware interface 189.

[0047] Figure 4 is a flowchart showing the processing content of the control device 18 of the induction heating device 1 according to Embodiment 1 of this disclosure. Figure 5 is a flowchart showing the processing content of the control device 18 of the induction heating device 1 according to Embodiment 1 of this disclosure that determines the first maximum heat output. Figure 5 shows, in more detail, the processing content of step S102 in Figure 4. The processing performed by the control device 18 will be explained using Figures 4 and 5. The control device 18 performs the processing shown in Figure 4 when the power to the induction heating device 1 is on and there is a change in the heating status. A change in the heating status means that the user changes the heat output by operating the operating device 20, or changes the object to be heated 16. Note that changing the object to be heated 16 includes both changing the first object to be heated 16a and changing the second object to be heated 16b.

[0048] Step S101 is a process that is executed when the control device 18 starts processing. In step S101, the placement determination unit 184 of the control device 18 determines whether the first object to be heated 16a is placed on the first heating coil 15a and the second object to be heated 16b is placed on the second heating coil 15b. Specifically, the placement determination unit 184 determines whether the resistance value of the first object to be heated 16a and the resistance value of the second object to be heated 16b are equal to or greater than the second resistance threshold stored in the storage unit 182. Step S101 ends when the placement determination unit 184 determines whether the conditions are met.

[0049] Step S102 is performed when it is determined in step S101 that the first object to be heated 16a is placed on the first heating coil 15a and the second object to be heated 16b is placed on the second heating coil 15b (step S101, Yes). In step S102, the determination unit 183 of the control device 18 determines the first maximum heating power. More specifically, the process in step S102 is the process from steps S111 to S116, as shown in Figure 5. The processes in steps S111 to S116 will be explained in detail below.

[0050] Step S111 is executed when the processing in step S102 begins. In step S111, the determination unit 183 of the control device 18 calculates the differential power. Step S111 ends when the determination unit 183 has calculated the differential power.

[0051] Step S112 is performed after the processing in step S111. In step S112, the determination unit 183 of the control device 18 determines the first characteristic power of the heated object. More specifically, the determination unit 183 obtains a power value stored in the storage unit 182 that corresponds to the resistance value calculated from the values ​​of the first voltage and the first current. Step S112 ends when the determination unit 183 has determined the first characteristic power of the heated object.

[0052] Step S113 is a process that is executed after the processing in step S112. In step S113, the determination unit 183 of the control device 18 determines whether the differential power calculated in step S111 is smaller than the first heated object characteristic power determined in step S112. Step S113 ends when the determination unit 183 determines whether the condition is met.

[0053] Step S114 is executed when, in step S113, it is determined that the differential power is smaller than the first characteristic power of the heated object (step S113, Yes). In step S114, the determination unit 183 of the control device 18 determines the first maximum power to be the differential power. Step S114 ends when the determination unit 183 has determined the first maximum power.

[0054] Step S115 is executed when, in step S113, it is determined that the differential power is not less than the first characteristic power of the heated object (step S113, No). In step S115, the determination unit 183 of the control device 18 determines the first maximum power to be the first characteristic power of the heated object. Step S115 ends when the determination unit 183 determines the first maximum power.

[0055] Step S116 is performed after the processing in step S114 or after the processing in step S115. In step S116, the determination unit 183 of the control device 18 determines the first maximum heating power by obtaining the first maximum heating power corresponding to the first maximum power determined in step S114 or step S115 from the storage unit 182. Step S116 ends when the determination unit 183 has determined the first maximum heating power.

[0056] When the process in step S116 is completed, the control device 18 terminates the process of determining the first maximum firepower. In other words, the process in step S102 is completed.

[0057] If, in step S101, it is determined that the first object to be heated 16a is not placed on the first heating coil 15a, and the second object to be heated 16b is not placed on the second heating coil 15b (step S101, No), the control device 18 terminates the process.

[0058] Step S103 is a process that is executed after the processing in step S102. In step S103, the signal generation unit 185 of the control device 18 generates a control signal for the inverter unit 13 and a signal indicating the notification content for the notification device 19. Step S103 ends when the signal generation unit 185 has generated the control signal and the signal indicating the notification content.

[0059] Step S104 is a process that is executed after the processing in step S103. In step S104, the transmitting / receiving unit 181 of the control device 18 transmits a signal to the induction heating device 1. Specifically, the transmitting / receiving unit 181 transmits a signal to the notification device 19 indicating the notification content generated in step S103. The transmitting / receiving unit 181 also transmits a control signal generated in step S103 to the inverter unit 13. When the processing in step S104 is completed, the control device 18 terminates its processing.

[0060] Figure 6 is a diagram showing the notification content of the notification device 19 of the induction heating device 1 according to Embodiment 1 of the present disclosure. As shown in Figure 6, the notification device 19 has a current heat output display unit 191 and a first maximum heat output display unit 192. The current heat output display unit 191 displays the current heat output output by the first inverter 13a. The first maximum heat output display unit 192 displays the first maximum heat output. The first maximum heat output display unit 192 may also display a message indicating that there is no limit to the first maximum heat output, i.e., that the first maximum heat output is at the maximum level. The notification device 19 may also be configured to display the current heat output output by the second inverter 13b.

[0061] Embodiment 2. The induction heating device 2 according to Embodiment 2 will now be described. In Embodiment 2, the same reference numerals are used for the same components as in Embodiment 1 of this disclosure, and descriptions of the same or corresponding parts will be omitted.

[0062] Figure 7 shows the notification content in the notification device 29 of the induction heating device 2 according to Embodiment 2 of this disclosure when the first maximum power is differential power. Figure 8 shows the notification content in the notification device 29 of the induction heating device 2 according to Embodiment 2 of this disclosure when the first maximum power is the first characteristic power of the heated object. The notification content of the induction heating device 2 according to Embodiment 2 differs from that of the induction heating device 1 according to Embodiment 1. The configuration of the notification device 29, excluding the notification content, is the same as that of the induction heating device 1, so a description is omitted.

[0063] As shown in Figures 7 and 8, the notification device 29 includes a current firepower display unit 191, a first maximum firepower display unit 192, a restriction reason display unit 291, and a restriction release action display unit 292. The current firepower display unit 191 and the first maximum firepower display unit 192 have the same configuration as the notification device 19 of Embodiment 1, so their description is omitted.

[0064] The limitation reason display unit 291 notifies the user of the reason why the first maximum heat output is not at its maximum level if it is not at its maximum level. Specifically, as shown in Figures 7 and 8, the limitation reason display unit 291 indicates whether the reason the first maximum heat output is not at its maximum is due to a power limitation or a limitation due to the characteristics of the object being heated. This configuration allows the induction heating device 2 to appropriately notify the user of the power limitation status.

[0065] The restriction release action display unit 292, when the magnitude of the first maximum heat output is not at its maximum level, proposes and notifies the user of the necessary actions to maximize the first maximum heat output. If the first maximum power is differential power, as shown in Figure 7, the restriction release action display unit 292 proposes to lower the output power of the second inverter 13b, that is, to lower the heat output level. Also, if the first maximum power is the characteristic power of the first heated object, as shown in Figure 8, the restriction release action display unit 292 proposes to replace the first heated object 16a. By having this configuration, the induction heating device 2 has the effect of being able to propose necessary actions to the user according to the situation.

[0066] In addition, the first inverter 13a and the second inverter 13b in the inverter section 13 of the induction heating device according to Embodiment 1 and Embodiment 2 are configured in advance depending on their location, but are not limited to this. When the power to the induction heating device is turned on, the user may select the inverter whose power is preferentially limited, i.e., the first inverter. Alternatively, the first inverter may be determined by the order in which heating is started.

[0067] Furthermore, the inverter section 13 of the induction heating device according to Embodiment 1 and Embodiment 2 has a configuration having two inverters: a first inverter 13a that supplies current to the first heating coil 15a and a second inverter 134b that supplies current to the second heating coil 15b, but is not limited to this configuration. The number of inverters is not limited as long as the configuration has two or more inverters.

[0068] Furthermore, in the induction heating apparatus according to Embodiment 1 and Embodiment 2, the first characteristic power of the object to be heated is determined by determining whether it is magnetic or non-magnetic from the resistance value of the object to be heated 16, but a configuration may be used to determine whether it is magnetic or non-magnetic using other indicators. For example, a configuration may be used in which the magnetism of the object to be heated is directly measured.

[0069] Furthermore, while the notification devices according to Embodiments 1 and 2 are configured to provide text notifications on a display, they are not limited to this configuration as long as they can notify the user of the first maximum firepower. For example, the first maximum firepower may be notified by sound or light. Alternatively, a combination of multiple notification methods may be used. Furthermore, some information may be notified by text, and some information by sound.

[0070] Furthermore, in the induction heating apparatus according to Embodiment 1 and Embodiment 2, when the resistance value of the first object to be heated 16a is greater than a predetermined first resistance threshold, the configuration is such that the first characteristic power of the first object to be heated is greater than when the resistance value of the first object to be heated 16a is less than the first resistance threshold, but the apparatus is not limited to this configuration. It may also have a configuration in which there are multiple resistance thresholds, and the first characteristic power of the first object to be heated corresponding to each threshold is stored in the storage unit. In addition, the storage unit may be configured to store a relational expression between the resistance value of the object to be heated and the first characteristic power of the first object to be heated.

[0071] Furthermore, in the induction heating apparatus according to Embodiment 1 and Embodiment 2, the determination of whether an object to be heated is placed is made based on whether the resistance value of the first object to be heated 16a and the resistance value of the second object to be heated 16b are equal to or greater than a second resistance threshold, but this is not limited to this configuration. The determination of whether an object to be heated is placed may be made using an indicator other than current. For example, a weight sensor may be used.

[0072] Furthermore, in the induction heating apparatus according to Embodiment 1 and Embodiment 2, the determination of the first maximum heat output is performed when there is a change in the heating conditions, but this is not limited to this configuration. For example, the induction heating apparatus may be configured to determine the first maximum heat output at regular intervals.

[0073] Furthermore, in the induction heating apparatus according to Embodiment 1 and Embodiment 2, the induction heating apparatus includes a detection device 17 as a component, but it may also be configured without including a detection device as a component. The induction heating apparatus only needs to be configured to acquire the results detected by the detection device.

[0074] Furthermore, in the induction heating apparatus according to Embodiment 1 and Embodiment 2, the notification device and the operating device are composed of separate devices, but they may be the same device.

[0075] The configurations shown in the embodiments described above are merely examples of the content of this disclosure and can be combined with other known technologies. Furthermore, it is possible to omit or modify parts of the configuration without departing from the gist of this disclosure.

[0076] The various forms of this disclosure are summarized below as an appendix. (Note 1) An inverter unit having a first inverter and a second inverter, A heating unit having a first heating coil continuously driven by the first inverter and a second heating coil continuously driven by the second inverter, A control unit that controls the inverter unit, A notification unit that notifies the user of information regarding the first maximum power, which is the maximum power that the first inverter can output, when an object to be heated is placed on the position heated by the first heating coil and the position heated by the second heating coil, respectively. It has, The first maximum power is the smaller of the following two values: the maximum power that the inverter unit can output minus the output power of the second inverter, and the first characteristic power of the object to be heated, which is determined from the characteristics of the object placed at the position heated by the first heating coil. Induction heating device. (Note 2) The information relating to the first maximum power refers to information indicating the output power of a thermal power plant that can output power corresponding to the first maximum power. The induction heating apparatus according to claim 1. (Note 3) The determination unit that determines the first maximum power when the object to be heated is changed. Furthermore, When the determination unit determines the first maximum power, the notification unit notifies the user of information regarding the first maximum power. An induction heating device as described in Appendix 1 or 2. (Note 4) The aforementioned operating unit, which is operated by the user, The determination unit determines the first maximum power when the user operates the operation unit while the object to be heated is placed on the position heated by the first heating coil and the position heated by the second heating coil, respectively. It further possesses, When the determination unit determines the first maximum power, the notification unit notifies the user of information regarding the first maximum power. An induction heating device as described in any one of the items 1 to 3 of the appendix. (Note 5) The characteristic of the object to be heated is the electrical resistance value of the object to be heated. When the electrical resistance value is greater than or equal to a predetermined threshold, the characteristic power of the first heated object is greater than when the electrical resistance value is less than the threshold. An induction heating device as described in any one of the items 1 to 4 of the appendix. (Note 6) The information indicating the outputtable heating power is information that shows the magnitude of the heating power in multiple stages. If the output power is not at its maximum level, the notification unit notifies the user of the reason why the output power is not at its maximum level. The induction heating device described in Appendix 2. (Note 7) The information indicating the outputtable heating power is information that shows the magnitude of the heating power in multiple stages. If the output power is not at its maximum level, the notification unit notifies the user of the actions necessary to maximize the output power. Inductable device as described in Appendix 2 or 6. (Note 8) The notification unit notifies a suggestion to reduce the output power of the second inverter if the maximum output power is not at its maximum level, and the value obtained by subtracting the output power of the second inverter from the value of the power that the inverter unit can output is smaller than the value of the first heated material characteristic power. The induction heating device described in Appendix 7. (Note 9) The notification unit, when the maximum output power is not at its maximum level and the value of the first heated object characteristic power is less than the value obtained by subtracting the output power of the first inverter from the value of the power that the inverter unit can output, notifies the notification of a suggestion to replace the heated object placed in the position heated by the first heating coil. An induction heating device as described in Appendix 7 or 8. (Note 10) The control unit will not accept any operation from the user if the user performs an operation that causes the output power of the first inverter to exceed the first maximum power. The induction heating device described in Appendix 4. (Note 11) The notification unit notifies the user that if the user performs an operation that causes the output power of the first inverter to exceed the first maximum power, the notification unit will not accept the user's operation. The induction heating device described in Appendix 10. (Note 12) An induction heating device comprising: a first inverter; an inverter unit having a second inverter; a heating unit having a first heating coil continuously driven by the first inverter; a second heating coil continuously driven by the second inverter; a control unit for controlling the inverter unit; and a notification unit for notifying information regarding a first maximum power, which is the maximum power that the first inverter can output, when an object to be heated is placed on a position heated by the first heating coil and a position heated by the second heating coil, respectively. The control unit sets the first maximum power to the smaller of the value obtained by subtracting the output power of the first inverter from the power value that the inverter unit can output, and the value of the first characteristic power of the object to be heated, which is determined from the characteristics of the object to be heated placed at the position to be heated by the first heating coil. An induction heating method comprising: [Explanation of Symbols]

[0077] 1 Induction heating device, 2 Induction heating device, 10 AC power supply, 11 Rectifier circuit, 12 Filter, 13 Inverter section, 13a First inverter, 13b Second inverter, 14 Resonant capacitor, 14a First resonant capacitor, 14b Second resonant capacitor, 15 Heating section, 15a First heating coil, 15b Second heating coil, 16 Object to be heated, 16a First object to be heated, 16b Second object to be heated, 17 Detection device, 18 Control device, 19 Notification device, 20 Operation device, 29 Notification device, 171 Voltage detection unit, 171a First voltage detection unit, 171b Second voltage detection unit, 172 Current detection unit, 172a First current detection unit, 172b Second current detection unit, 181 Transmit / receive unit, 182 Memory unit, 183 Determination unit, 184 Placement determination unit, 185 Signal generation unit, 186 Processor, 187 Memory, 188 Storage, 189 Hardware interface, 191 Current firepower display unit, 192 First maximum firepower display unit, 291 Restriction reason display unit, 292 Restriction release action display unit.

Claims

1. An inverter unit having a first inverter and a second inverter, A heating unit having a first heating coil continuously driven by the first inverter and a second heating coil continuously driven by the second inverter, A control unit that controls the inverter unit, A notification unit that notifies the user of information regarding the first maximum power, which is the maximum power that the first inverter can output, when an object to be heated is placed on the position heated by the first heating coil and the position heated by the second heating coil, respectively. It has, The first maximum power is the smaller of the following two values: the maximum power that the inverter unit can output minus the output power of the second inverter, and the first characteristic power of the object to be heated, which is determined from the characteristics of the object placed at the position heated by the first heating coil. Induction heating device.

2. The information relating to the first maximum power refers to information indicating the output power of a thermal power plant that can output power corresponding to the first maximum power. The induction heating apparatus according to claim 1.

3. The determination unit determines the first maximum power when the object to be heated is changed. Furthermore, When the determination unit determines the first maximum power, the notification unit notifies the user of information regarding the first maximum power. The induction heating apparatus according to claim 1.

4. The aforementioned operating unit, which is operated by the user, The determination unit determines the first maximum power when the user operates the operation unit while the object to be heated is placed on the position heated by the first heating coil and the position heated by the second heating coil, respectively. It further possesses, When the determination unit determines the first maximum power, the notification unit notifies the user of information regarding the first maximum power. The induction heating apparatus according to claim 1.

5. The characteristic of the object to be heated is the electrical resistance value of the object to be heated. When the electrical resistance value is greater than or equal to a predetermined threshold, the characteristic power of the first heated object is greater than when the electrical resistance value is less than the threshold. The induction heating apparatus according to claim 1.

6. The information indicating the outputtable heating power is information that shows the magnitude of the heating power in multiple stages. If the output power is not at its maximum level, the notification unit notifies the user of the reason why the output power is not at its maximum level. The induction heating apparatus according to claim 2.

7. The information indicating the outputtable heating power is information that shows the magnitude of the heating power in multiple stages. If the output power is not at its maximum level, the notification unit notifies the user of the actions necessary to maximize the output power. The inductable device according to claim 2.

8. The notification unit notifies a suggestion to reduce the output power of the second inverter if the maximum output power is not at its maximum level, and the value obtained by subtracting the output power of the second inverter from the value of the power that the inverter unit can output is smaller than the value of the first heated material characteristic power. The induction heating apparatus according to claim 7.

9. The notification unit, when the maximum output power is not at its maximum level and the value of the first heated object characteristic power is less than the value obtained by subtracting the output power of the first inverter from the value of the power that the inverter unit can output, notifies the user of a suggestion to replace the heated object placed in the position heated by the first heating coil. The induction heating apparatus according to claim 7.

10. The control unit will not accept the user's operation if the user performs an operation that causes the output power of the first inverter to exceed the first maximum power. The induction heating apparatus according to claim 4.

11. The notification unit notifies the user that if the user performs an operation that causes the output power of the first inverter to exceed the first maximum power, the notification unit will not accept the user's operation. The induction heating apparatus according to claim 10.

12. An induction heating device comprising: a first inverter; an inverter unit having a second inverter; a heating unit having a first heating coil continuously driven by the first inverter; a second heating coil continuously driven by the second inverter; a control unit for controlling the inverter unit; and a notification unit for notifying information regarding a first maximum power, which is the maximum power that the first inverter can output, when an object to be heated is placed on a position heated by the first heating coil and a position heated by the second heating coil, respectively. The control unit sets the first maximum power to the smaller of the following two values: the value obtained by subtracting the output power of the first inverter from the value of power that the inverter unit can output, and the value of the first characteristic power of the object to be heated, which is determined from the characteristics of the object to be heated placed at the position to be heated by the first heating coil. An induction heating method comprising:

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