Electromagnetic cooking utensil, dry burning detection method and device thereof, controller and medium

Abstract

The invention discloses an electromagnetic cooking utensil, a dry burning detection method and device thereof, a controller and a medium, and relates to the technical field of cooking utensils. The method comprises the following steps: acquiring a current parameter in a heating process of the electromagnetic cooking utensil; and determining that the electromagnetic cooking utensil is in a dry burning state under the condition that the current parameter meets a preset dry burning condition. In this way, reliable dry burning protection is achieved, additional hardware cost is not increased, and the reliability of the electromagnetic cooking utensil is improved.

Description

Electromagnetic cooking appliances and their dry-burning detection methods, devices, controllers and media Technical Field

[0001] This invention relates to the field of cooking appliance technology, and in particular to a dry-burn detection method for an electromagnetic cooking appliance, a controller, a dry-burn detection device for an electromagnetic cooking appliance, a computer-readable storage medium, and an electromagnetic cooking appliance. Background Technology

[0002] Electromagnetic induction heating cookers, for safety and electrical reliability reasons, typically have a dry-burn protection mechanism. Generally, this can be determined by testing the absolute value of the pot's bottom temperature. However, in actual use, due to different cooking methods, such as frying, the pot bottom temperature is usually quite high. Therefore, simply using the absolute value of the pot bottom temperature to determine whether the cooker is dry-burning can limit some functions. If a higher temperature value is set to accommodate some cooking methods, the absolute temperature setting may be too high, leading to reliability issues, especially for the core components of electromagnetic heating, such as the coil. In severe cases, the coil wires may melt or fail due to excessive temperature, or the coil support may melt or carbonize, or even catch fire. Based on these risks, electromagnetic heating cookers usually use the slope of the pot bottom temperature rise as a condition for determining whether dry-burning has occurred. The advantage of this method is that it does not use absolute temperature, so the absolute temperature of the components will not be too high, thus avoiding reliability or safety issues. However, when determining whether a cooker is dry-burning based on the temperature slope, the slope is usually set based on a favorable initial state, such as a low initial temperature or room temperature. The slope is also typically a threshold set based on high-probability usage scenarios, so this threshold may not cover situations where the cooker's initial temperature is high. Induction cookers usually use temperature sensors (mostly thermistors) to detect the temperature of the lid, equivalent to the temperature of the cookware. Due to structural tolerances and assembly process issues, the temperature sensor and lid may not fit tightly, leading to detection lag and lower temperature readings, which also causes the slope to fail to meet the initially set threshold. Furthermore, the cookware used by the user may not be completely flat and cannot fit perfectly against the induction cooker panel. Alternatively, the cookware may have an uneven bottom due to prolonged use or previous dry-burning, which can also result in lower detected temperatures or a slope that does not meet the threshold. Summary of the Invention

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. Therefore, the first objective of this invention is to provide a method for detecting dry burning in electromagnetic cooking appliances, which involves acquiring current parameters during the heating process of the electromagnetic cooking appliance; and determining that the electromagnetic cooking appliance is in a dry burning state when the current parameters meet preset dry burning conditions. This achieves reliable dry burning protection without increasing additional hardware costs, thus improving the reliability of electromagnetic cooking appliances.

[0004] The second objective of this invention is to provide a controller.

[0005] The third objective of this invention is to provide a dry-burn detection device for electromagnetic cooking appliances.

[0006] The fourth objective of this invention is to provide a computer-readable storage medium.

[0007] The fifth objective of this invention is to provide an electromagnetic cooking appliance.

[0008] To achieve the above objectives, a first aspect of the present invention provides a method for detecting dry burning of an electromagnetic cooking appliance, the method comprising: acquiring current parameters during the heating process of the electromagnetic cooking appliance; and determining that the electromagnetic cooking appliance is in a dry burning state when the current parameters meet preset dry burning conditions.

[0009] According to one embodiment of the present invention, the current parameter includes the current change rate, and determining that the current parameter meets the preset dry burning conditions includes: determining that the preset dry burning conditions are met when the current change rate is not a preset threshold.

[0010] According to an embodiment of the present invention, the detection method further includes: obtaining the bottom temperature of the electromagnetic cooking appliance; and obtaining the rate of change of current when the bottom temperature is greater than or equal to a first preset temperature threshold and less than a second preset temperature threshold.

[0011] According to one embodiment of the present invention, the current parameter includes a current value, and determining that the current parameter meets the preset dry-burning conditions includes: obtaining the bottom temperature of the electromagnetic cooking appliance; if the current value is greater than the preset current threshold when the bottom temperature is greater than or equal to a second preset temperature threshold, then determining that the preset dry-burning conditions are met.

[0012] According to one embodiment of the present invention, when it is determined that the electromagnetic cooking appliance is in a dry-burning state, the above detection method further includes: controlling the electromagnetic cooking appliance to stop heating.

[0013] According to one embodiment of the present invention, the current value includes the high-frequency current value and / or low-frequency current value of the electromagnetic cooking appliance; the current change rate includes the high-frequency current change rate and / or low-frequency current change rate of the electromagnetic cooking appliance.

[0014] According to an embodiment of the present invention, when it is determined that the preset dry-burning conditions are met, the above detection method further includes: controlling the electromagnetic cooking appliance to heat intermittently at a preset power; if the current value is still greater than the preset current threshold after a preset time, it is determined that the electromagnetic cooking appliance is in a dry-burning state.

[0015] To achieve the above objectives, a second aspect of the present invention provides a controller, comprising: a memory, a processor, and a program stored in the memory and executable on the processor, wherein when the processor executes the program, it implements the aforementioned method for detecting dry burning of an electromagnetic cooking appliance.

[0016] To achieve the above objectives, a third aspect of the present invention provides a dry-burning detection device for an electromagnetic cooking appliance. The device includes: a detection module for acquiring current parameters during the heating process of the electromagnetic cooking appliance; and a determination module for determining that the electromagnetic cooking appliance is in a dry-burning state when the current parameters meet preset dry-burning conditions.

[0017] To achieve the above objectives, a fourth aspect of the present invention provides a computer-readable storage medium storing a dry-burn detection program for an electromagnetic cooking appliance, which, when executed by a processor, implements the aforementioned dry-burn detection method for an electromagnetic cooking appliance.

[0018] To achieve the above objectives, a fifth aspect of the present invention provides an electromagnetic cooking appliance, including a memory, a processor, and a dry-burn detection program for the electromagnetic cooking appliance stored in the memory and executable on the processor. When the processor executes the dry-burn detection program for the electromagnetic cooking appliance, the aforementioned dry-burn detection method for the electromagnetic cooking appliance is implemented.

[0019] According to embodiments of the present invention, an electromagnetic cooking appliance and its dry-burn detection method, apparatus, controller, and medium acquire current parameters during the heating process of the electromagnetic cooking appliance; if the current parameters meet preset dry-burn conditions, the electromagnetic cooking appliance is determined to be in a dry-burn state. Thus, reliable dry-burn protection is achieved without increasing additional hardware costs, improving the reliability of the electromagnetic cooking appliance. Attached Figure Description

[0020] Figure 1 is a schematic diagram of a half-bridge circuit topology according to some embodiments of the present invention;

[0021] Figure 2 is a schematic diagram of a single-transistor circuit topology according to some embodiments of the present invention;

[0022] Figure 3 is a schematic diagram of a single-transistor circuit topology according to some other embodiments of the present invention;

[0023] Figure 4 is a schematic diagram of a single-transistor circuit topology according to some embodiments of the present invention;

[0024] Figure 5 is a schematic diagram of a single-transistor circuit topology according to some embodiments of the present invention;

[0025] Figure 6 is an equivalent circuit diagram of the coupling between the coil and the electromagnetic cooker according to some embodiments of the present invention;

[0026] Figure 7 is a graph showing the permeability-current-temperature of an electromagnetic cookware according to some embodiments of the present invention.

[0027] Figure 8 is a flowchart of a dry-burning detection method for electromagnetic cooking appliances according to some embodiments of the present invention;

[0028] Figure 9 is a block diagram of a controller according to some embodiments of the present invention;

[0029] Figure 10 is a block diagram of a dry-burn detection device for an electromagnetic cooking appliance according to some embodiments of the present invention.

[0030] Figure 11 is a block diagram of an electromagnetic cooking appliance according to some embodiments of the present invention. Detailed Implementation

[0031] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0032] The electromagnetic cooking appliances and their dry-burn detection methods, devices, controllers, and media according to embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0033] In some embodiments, the electromagnetic cooking appliance can be an electromagnetic cookware. In this embodiment of the invention, an electromagnetic cookware is used as an example for explanation, but this is not intended to limit the invention. The electromagnetic heating circuit control architecture of the electromagnetic cooking appliance mainly includes half-bridge circuit topology control and single-tube circuit topology control.

[0034] For example, referring to Figure 1, in the half-bridge circuit topology control, L / N is the power input, which is generally the mains power supply, and the domestic rated standard is 220V / 50Hz.

[0035] BD101 / CX01 / L is an AC rectifier circuit. The function of a rectifier circuit is to convert AC power into DC power to control the power switches in the half-bridge inverter circuit. Rectifier circuits are generally composed of diodes, whose function is to unidirectionally conduct the current during the positive or negative half-cycle of the AC power supply, converting it into DC current. In the electromagnetic heating half-bridge topology, since the half-bridge inverter circuit needs to control the direction and magnitude of the current, a DC power supply is required for control. The rectifier circuit's role is to convert AC power into DC power. Simultaneously, the rectifier circuit and safety capacitor CX01 also act as filters, filtering out high-frequency noise in the AC power supply to ensure the normal operation of the half-bridge inverter circuit.

[0036] IGBT01 / IGBT02 / C01 / C02, together with coil L01, form a half-bridge inverter circuit, the core component of the electromagnetic heating system. Its function is to convert the DC power supply output into high-frequency AC power to heat the electromagnetic heating coil. IGBT01 / IGBT02 is an IGBT (Insulated Gate Bipolar Transistor) module composed of a power switching transistor and a diode connected in reverse parallel. The two power switching transistors in the half-bridge inverter circuit control the switching on and off of the alternating cycle, thereby controlling the magnitude and frequency of the output high-frequency AC voltage. Typically, the control method can be PWM, SPWM, etc. The two parallel capacitors C01 / C02 serve to store and output electrical energy. When the power switch IGBT01 is turned on, the current in coil L01 begins to increase, and the coil and capacitor store some electrical energy. When the power switch IGBT01 is turned off and IGBT01 is turned on, the current increases in the opposite direction, and the magnetic field in the coil and capacitor releases the stored electrical energy. In both processes, the current flows through the coil and is output to the load, thus realizing the output of high-frequency AC voltage.

[0037] TL01 and RK01 are high-frequency and low-frequency current sampling components, respectively. The sampled high-frequency current signal is rectified and filtered before being output to the controller. The controller adjusts the frequency of the control signal and controls the on / off state of the output based on the phase and amplitude of the high-frequency current. The low-frequency current sample is differentially amplified before being output to the controller. The controller outputs the closed-loop control power based on the magnitude of the low-frequency current.

[0038] Referring to Figure 2, in the single-transistor circuit topology control, L / N is the power input, which is generally the AC power supply. The domestic rated standard is 220V / 50Hz.

[0039] BD101 / CX01 / L is an AC rectifier circuit. The function of a rectifier circuit is to convert AC power into DC power to control the power switching transistors in a single-transistor inverter circuit. A rectifier circuit typically consists of diodes, whose function is to unidirectionally conduct the current during the positive or negative half-cycle of the AC power supply, converting it into DC current. In a single-transistor topology for electromagnetic heating, since the single-transistor inverter circuit needs to control the direction and magnitude of the current, a DC power supply is required. The rectifier circuit's role is to convert AC power into DC power. Simultaneously, the rectifier circuit, along with the safety capacitor CX01 and the differential-mode inductor L, also acts as a filter, removing high-frequency noise from the AC power supply and ensuring the normal operation of the single-transistor inverter circuit.

[0040] IGBT01 / C01 / CX02, together with coil L01, form a single-transistor inverter circuit, the core component of the electromagnetic heating system. Its function is to convert the electrical energy output from the DC power supply into high-frequency AC energy to power the electromagnetic heating coil. IGBT01 converts the DC power supply's output into high-frequency AC energy for the electromagnetic heating coil. The power switch periodically controls the on / off time, thereby controlling the magnitude and frequency of the output high-frequency AC voltage. The capacitor C01 connected in parallel with L01 serves to store and output electrical energy. When the power switch IGBT01 is turned on, the current in coil L01 begins to increase, and the coil stores a portion of electrical energy. When the power switch IGBT01 is turned off, the coil releases energy into capacitor C01. After the energy release is complete, capacitor C01 releases the stored energy back into the coil. During this process, current flows through the coil and is output to the load, thus achieving the output of high-frequency AC voltage.

[0041] TL01 and RK01 are high-frequency and low-frequency current sampling components, respectively. The sampled high-frequency current signal is rectified and filtered before being output to the controller. The controller adjusts the frequency of the control signal and controls the on / off state of the output based on the phase and amplitude of the high-frequency current. The low-frequency current sample is differentially amplified before being output to the controller. The controller outputs the closed-loop control power based on the magnitude of the low-frequency current.

[0042] It should be noted that in a single-tube topology, there are various flexible methods for sampling high and low frequency currents, depending on the product's configuration and reliability requirements. For example, referring to Figure 2, both high-frequency and low-frequency currents can be sampled simultaneously. Referring to Figure 3, only low-frequency current sampling is possible. Referring to Figure 4, only high-frequency current sampling is possible. Referring to Figure 5, high-frequency current sampling can be achieved using a sampling resistor for low-frequency current.

[0043] As shown in Figure 6, the equivalent circuit of the coupling between the coil and the induction cooker, based on the principle of electromagnetic heating, can be represented as a series connection of an inductor and a resistor. Since induction cookers typically use ferromagnetic materials, these materials exhibit different equivalent inductances (Lx) and equivalent resistances (Rx) in the equivalent circuit. These parameters change with the temperature of the cooker, and this change is usually described by the material's permeability, which changes with temperature. The permeability of a material has a temperature characteristic known as the Curie temperature characteristic. The Curie temperature refers to the temperature at which a ferromagnetic material loses its magnetism at high temperatures, and its value is related to the material's chemical composition and crystal structure. Below the Curie temperature, ferromagnetic materials exhibit strong magnetism, while above the Curie temperature, the magnetism gradually weakens until it is lost. The permeability of a ferromagnetic material is a physical quantity describing the material's magnetism; it is the ratio of the material's magnetization to the strength of the applied magnetic field. Below the Curie temperature, the permeability of ferromagnetic materials is usually high because the material's magnetization is greater. Above the Curie temperature, the permeability of ferromagnetic materials decreases sharply because magnetization decreases with increasing temperature, leading to a corresponding decrease in permeability. Furthermore, when the temperature of a ferromagnetic material exceeds the Curie temperature, its magnetism gradually disappears, and the permeability approaches zero. Therefore, the Curie temperature is one of the important factors affecting the permeability of ferromagnetic materials. Different materials exhibit significantly different Curie temperature points. For example, the Curie temperature for iron is 769℃, for nickel it is 358℃, for iron-silicon alloys it is 690℃, for ferrite permanent magnets it is 500℃, and for neodymium iron boron permanent magnets it is around 220℃. For composite materials, determining their Curie temperature requires considering the ferromagnetic properties of various components, such as ferrites and iron-based alloys. Generally, the Curie temperature of composite materials is lower than that of a single ferromagnetic material because the interactions between the various components in the composite material affect its magnetic properties. In addition, Curie temperature is affected by a variety of factors, including the chemical composition of the material, crystal structure, crystal defects, and external magnetic field. The actual Curie temperature of electromagnetically heated cookware is lower due to the influence of material purity, manufacturing process, and application scenario, and is generally around 400℃.

[0044] As shown in Figure 7, the permeability of the electromagnetic cookware changes significantly at the Curie temperature. Above the Curie temperature, the permeability drops sharply, which is clearly reflected in the equivalent circuit of the coupling between the coil and the cookware as a sharp decrease in the equivalent resistance Rx and a sharp increase in the system current. Based on this, this invention obtains the current parameters during the heating process of the electromagnetic cooking appliance and determines whether the appliance is in a dry-burning state based on these parameters. Thus, by adding the dry-burning detection method of this invention to the existing NTC (Negative Temperature Coefficient) protection measures, better dry-burning protection is achieved without increasing additional hardware costs, improving the reliability of the electromagnetic cooking appliance. Furthermore, by utilizing the system's inherent current sampling foundation, supplementary dry-burning protection measures are implemented, making the system's dry-burning protection more comprehensive and further improving product reliability.

[0045] Figure 8 is a flowchart of a dry-burning detection method for an electromagnetic cooking appliance according to some embodiments of the present invention. Referring to Figure 8, the dry-burning detection method for an electromagnetic cooking appliance according to embodiments of the present application may include the following steps:

[0046] S110, acquires the current parameters during the heating process of the electromagnetic cooking appliance.

[0047] Specifically, current parameters can include the rate of change of current and the current value. The rate of change of current or the current value during the heating process of the electromagnetic cooking appliance can be used to determine whether the electromagnetic cooking appliance is in a dry-burning state.

[0048] The electromagnetic cooker's built-in current sampling circuit senses changes in current during the heating process. In other words, the current sampling circuit can detect the current value in real time during heating, and then determine the rate of change of current based on the difference in current changes over a period of time. The specific methods for obtaining the current value and the rate of change of current are not specified here.

[0049] For example, referring to Figure 7, when the bottom temperature of the electromagnetic cooking appliance is between temperature point Ta and the Curie temperature point, the electromagnetic cooking appliance has already been dry-burned. The bottom temperature of the electromagnetic cooking appliance is still in the rising stage but has not yet reached a very high state. At this time, the resistance value of the equivalent resistance Rx is constantly increasing, but the current is decreasing. However, in general, when the electromagnetic cooking appliance is not dry-burning, the current change should theoretically be 0. Therefore, the slope of the current change can be used to determine whether the electromagnetic cooking appliance is in a dry-burning state.

[0050] Referring to Figure 7, according to the formula I = P / U, when the power input voltage U (rated mains voltage 220V) and operating power P (power required by the system or user) of the electromagnetic cooking appliance are constant, the current of the electromagnetic cooking appliance should be relatively constant. When the electromagnetic cooking appliance continues to work and the liquid inside has completely evaporated, the appliance is in a dry-burning state. If the appliance continues to heat, the temperature at the bottom of the appliance will continue to rise. When the temperature at the bottom of the appliance exceeds the Curie temperature, the resistance value of the equivalent resistance Rx will suddenly drop. According to Ohm's law I = U / Rx, when the power input voltage of the electromagnetic cooking appliance is constant, if the resistance value of the equivalent resistance Rx suddenly drops, the current value will suddenly rise. Therefore, the current value during the heating process of the electromagnetic cooking appliance can be used to determine whether the appliance is in a dry-burning state.

[0051] S120, if the current parameters meet the preset dry-burning conditions, determine that the electromagnetic cooking appliance is in a dry-burning state.

[0052] Specifically, before the bottom temperature of the electromagnetic cooking appliance reaches the Curie temperature, it can be determined whether the appliance is in a dry-burning state by judging whether the rate of change of current meets the corresponding preset dry-burning conditions. After the bottom temperature of the electromagnetic cooking appliance reaches the Curie temperature, it can be determined whether the current value meets the corresponding preset dry-burning conditions.

[0053] For example, if the rate of change of current meets the corresponding preset dry-burning conditions, the electromagnetic cooking appliance is determined to be in a dry-burning state; if the rate of change of current does not meet the corresponding preset dry-burning conditions, the electromagnetic cooking appliance is determined not to be in a dry-burning state.

[0054] The detection method of the present invention obtains the current parameters during the heating process of the electromagnetic cooking appliance and determines whether the electromagnetic cooking appliance is in a dry-burning state based on the current parameters. This achieves reliable dry-burning protection without increasing additional hardware costs and improves the reliability of the electromagnetic cooking appliance.

[0055] In some embodiments, the current parameter includes the current change rate. Determining that the current parameter meets the preset dry-burning conditions includes: determining that the preset dry-burning conditions are met when the current change rate is not a preset threshold. The preset threshold is calibrated according to actual conditions; for example, the preset threshold can be 0, and no specific limitation is made here.

[0056] Specifically, as described in the above embodiments, when the electromagnetic cooking appliance is not in a dry-burning state, the current change rate should theoretically be a preset threshold, for example, 0. When the electromagnetic cooking appliance is in a dry-burning state, the current will decrease. Therefore, by obtaining the current change rate and determining whether the current change rate is at the preset threshold, it can be determined whether the corresponding preset dry-burning condition is met. For example, if the current change rate is at the preset threshold, it is determined that the preset dry-burning condition is not met; if the current change rate is not at the preset threshold, it is determined that the preset dry-burning condition is met.

[0057] In some embodiments, the detection method further includes: acquiring the bottom temperature of the electromagnetic cooking appliance; and acquiring the rate of change of current when the bottom temperature is greater than or equal to a first preset temperature threshold and less than a second preset temperature threshold. The first and second preset temperature thresholds are calibrated according to actual conditions and are not specifically limited here.

[0058] Specifically, as described in the above embodiments, when the bottom temperature of the electromagnetic cooking appliance is greater than or equal to a first preset temperature threshold (e.g., temperature point Ta) and less than a second preset temperature threshold (the Curie temperature of the electromagnetic cooking appliance), the electromagnetic cooking appliance has already been dry-burned. At this time, the resistance value of the equivalent resistance Rx is constantly increasing, but the current is decreasing. Therefore, the bottom temperature of the electromagnetic cooking appliance can be detected by a temperature sensor installed at the bottom of the appliance. When the detected bottom temperature is greater than or equal to the first preset temperature threshold and less than the second preset temperature threshold, the rate of change of current can be obtained. Here, the slope of the current change K = ΔI / ΔT, where ΔI is the difference in the changing current, and ΔT is the time intercept, which is the time difference between two points in the changing current difference.

[0059] In this way, there is no need to wait for the bottom temperature of the electromagnetic cooking appliance to rise to the Curie temperature (the second preset temperature threshold), the protection temperature is lower, and the protection is more timely.

[0060] In some embodiments, the current parameter includes a current value. Determining that the current parameter meets the preset dry-burning conditions includes: acquiring the bottom temperature of the electromagnetic cooking appliance; if the current value is greater than a preset current threshold when the bottom temperature is greater than or equal to a second preset temperature threshold, then it is determined that the preset dry-burning conditions are met. The preset current threshold can be determined according to actual conditions and is not specifically limited here.

[0061] Specifically, as described in the above embodiments, when the bottom temperature of the electromagnetic cooking appliance is greater than or equal to the second preset temperature threshold (the Curie temperature point of the electromagnetic cooking appliance), the resistance value of the equivalent resistance Rx will suddenly decrease, and the current value will suddenly increase. Therefore, the bottom temperature of the electromagnetic cooking appliance can be detected by a temperature sensor installed at the bottom of the appliance. When the bottom temperature is detected to be greater than or equal to the second preset temperature threshold, the current value is obtained, and the current value is compared with a preset current threshold to determine whether the preset dry-burning condition is met. For example, if the current value is greater than the preset current threshold, it is determined that the preset dry-burning condition is met; if the current value is less than or equal to the preset current threshold, it is determined that the preset dry-burning condition is not met.

[0062] In some embodiments, when it is determined that the electromagnetic cooking appliance is in a dry-burning state, the detection method further includes: controlling the electromagnetic cooking appliance to stop heating.

[0063] Specifically, when it is determined that the electromagnetic cooking appliance is in a dry-burning state based on the rate of change of current or the current value, the electromagnetic cooking appliance can be directly controlled to stop heating, which can avoid damage to the electromagnetic cooking appliance to a certain extent and further improve the stability of the electromagnetic cooking appliance.

[0064] In some embodiments, the current value includes the high-frequency current value and / or low-frequency current value of the electromagnetic cooking appliance; the current change rate includes the high-frequency current change rate and / or low-frequency current change rate of the electromagnetic cooking appliance.

[0065] Specifically, high-frequency current sampling is faster and more accurate than low-frequency current sampling. Therefore, using high-frequency current to determine whether an electromagnetic cooking appliance is in a dry-burning state will be more timely and provide better protection. However, low-frequency current can also determine whether an electromagnetic cooking appliance is in a dry-burning state, but the effect will be delayed by a certain amount of time, generally by 3 to 5 seconds. Since the temperature is already very high, this time difference usually does not have a significant impact on the effect.

[0066] Furthermore, as can be seen from the above embodiments, regardless of whether the electromagnetic heating circuit control architecture of the electromagnetic cooking appliance is a half-bridge circuit topology control or a single-tube circuit topology control, the current sampling circuit built into the electromagnetic cooking appliance can sense the high-frequency current value and / or low-frequency current during the heating process. For example, referring to Figures 1 and 2, the current sampling circuit can sense the high-frequency current and low-frequency current during the heating process. Referring to Figure 3, the current sampling circuit can sense the low-frequency current during the heating process, and referring to Figure 4, the current sampling circuit can sense the high-frequency current during the heating process.

[0067] In other words, it is possible to determine whether an electromagnetic cooking appliance is in a dry-burning state by obtaining the high-frequency and / or low-frequency current values ​​during the heating process. Similarly, it is also possible to determine whether an electromagnetic cooking appliance is in a dry-burning state by obtaining the high-frequency and / or low-frequency current change rate during the heating process.

[0068] In some embodiments, when it is determined that the preset dry-burning conditions are met, the detection method further includes: controlling the electromagnetic cooking appliance to heat intermittently at a preset power; if the current value is still greater than a preset current threshold after a preset time, then it is determined that the electromagnetic cooking appliance is in a dry-burning state. The preset time is determined according to actual conditions and is not specifically limited here.

[0069] Specifically, if the current value is greater than the preset current threshold, it can be determined that the preset dry-burning condition is met. However, if the user moves the electromagnetic cooking appliance, it will also cause the current value to suddenly increase and exceed the preset current threshold. Therefore, after determining that the preset dry-burning condition is met based on the current value, it is necessary to control the electromagnetic cooking appliance to heat intermittently at the preset power for a preset time. After the preset time, the current value is compared with the preset current threshold to determine whether the electromagnetic cooking appliance is in a dry-burning state.

[0070] For example, if the current value is still greater than the preset current threshold after a preset time, it is determined that the electromagnetic cooking appliance is in a dry-burning state; if the current value is less than or equal to the preset current threshold after a preset time, it is determined that the electromagnetic cooking appliance is not in a dry-burning state.

[0071] In summary, this invention, based on the Curie temperature characteristics of the magnetic permeability of electromagnetic cooking appliances, obtains current parameters during the heating process of the electromagnetic cooking appliance and determines whether the appliance is in a dry-burning state based on these parameters. Thus, by adding the dry-burning detection method of this invention to the existing NTC protection measures, better dry-burning protection can be achieved without increasing additional hardware costs, improving the reliability of the electromagnetic cooking appliance. Furthermore, by utilizing the system's inherent current sampling foundation, supplementary dry-burning protection measures are implemented, making the system's dry-burning protection more comprehensive and further enhancing product reliability.

[0072] Corresponding to the above embodiments, this application also proposes a controller.

[0073] Referring to Figure 9, the controller 200 of this application includes a memory 210, a processor 220, and a program stored in the memory 210 and executable on the processor 220. When the processor 220 executes the program, it implements the aforementioned method for detecting dry burning of electromagnetic cooking appliances.

[0074] It should be noted that the above explanation of the embodiments and beneficial effects of the dry-burn detection method for electromagnetic cooking appliances also applies to the controller of the embodiments of the present invention. To avoid redundancy, it will not be elaborated in detail here.

[0075] Corresponding to the above embodiments, this application also proposes a dry-burning detection device for electromagnetic cooking appliances.

[0076] Referring to Figure 10, the dry-burn detection device 300 for electromagnetic cooking appliances includes: a detection module 310 and a determination module 320.

[0077] The detection module 310 is used to acquire the current parameters during the heating process of the electromagnetic cooking appliance. The determination module 320 is used to determine that the electromagnetic cooking appliance is in a dry-burning state when the current parameters meet the preset dry-burning conditions.

[0078] According to one embodiment of the present invention, the current parameter includes the current change rate, and the determining module 320 is specifically used to determine that the preset dry burning condition is met when the current change rate is not a preset threshold.

[0079] According to one embodiment of the present invention, the detection module 310 is specifically used to obtain the bottom temperature of the electromagnetic cooking appliance; and to obtain the current change rate when the bottom temperature is greater than or equal to a first preset temperature threshold and less than a second preset temperature threshold.

[0080] According to one embodiment of the present invention, the current parameter includes the current value, and the determining module 320 is specifically used to obtain the bottom temperature of the electromagnetic cooking appliance; if the bottom temperature is greater than or equal to a second preset temperature threshold, and the current value is greater than the preset current threshold, then it is determined that the preset dry burning condition is met.

[0081] According to one embodiment of the present invention, when it is determined that the electromagnetic cooking appliance is in a dry-burning state, the electromagnetic cooking appliance is controlled to stop heating.

[0082] According to one embodiment of the present invention, the current value includes the high-frequency current value and / or low-frequency current value of the electromagnetic cooking appliance; the current change rate includes the high-frequency current change rate and / or low-frequency current change rate of the electromagnetic cooking appliance.

[0083] According to an embodiment of the present invention, when it is determined that the preset dry-burning conditions are met, the determining module 320 is specifically used to control the electromagnetic cooking appliance to heat intermittently with a preset power. If the current value is still greater than the preset current threshold after a preset time, it is determined that the electromagnetic cooking appliance is in a dry-burning state.

[0084] It should be noted that the above explanation of the embodiments and beneficial effects of the dry-burning detection method for electromagnetic cooking appliances also applies to the dry-burning detection device for electromagnetic cooking appliances in the embodiments of the present invention. To avoid redundancy, it will not be elaborated in detail here.

[0085] Corresponding to the above embodiments, this application also proposes a computer-readable storage medium.

[0086] The present application provides a computer-readable storage medium storing a dry-burn detection program for an electromagnetic cooking appliance, which, when executed by a processor, implements the aforementioned dry-burn detection method for an electromagnetic cooking appliance.

[0087] It should be noted that the above explanation of the embodiments and beneficial effects of the dry-burn detection method for electromagnetic cooking appliances is also applicable to the computer-readable storage medium of the embodiments of the present invention. To avoid redundancy, it will not be elaborated in detail here.

[0088] Corresponding to the above embodiments, this application also proposes an electromagnetic cooking appliance.

[0089] Referring to Figure 11, the electromagnetic cooking appliance 400 of this application includes a memory 410, a processor 420, and a dry-burn detection program for the electromagnetic cooking appliance stored in the memory 410 and executable on the processor 420. When the processor 420 executes the dry-burn detection program for the electromagnetic cooking appliance, it implements the aforementioned dry-burn detection method for the electromagnetic cooking appliance.

[0090] It should be noted that the above-described embodiments and explanations of the beneficial effects of the dry-burning detection method for electromagnetic cooking appliances are also applicable to electromagnetic cooking appliances in the embodiments of the present invention. To avoid redundancy, they will not be elaborated in detail here.

[0091] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0092] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0093] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0094] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0095] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0096] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for detecting dry burning in an electromagnetic cooking appliance, characterized in that, The method includes: acquiring current parameters during the heating process of the electromagnetic cooking appliance; and determining that the electromagnetic cooking appliance is in a dry-burning state when the current parameters meet preset dry-burning conditions.

2. The method according to claim 1, characterized in that, The current parameter includes the current change rate. Determining that the current parameter meets the preset dry-burning conditions includes: determining that the preset dry-burning conditions are met when the current change rate is not a preset threshold.

3. The method according to claim 2, characterized in that, The method further includes: obtaining the bottom temperature of the electromagnetic cooking appliance; and obtaining the current change rate when the bottom temperature is greater than or equal to a first preset temperature threshold and less than a second preset temperature threshold.

4. The method according to claim 1, characterized in that, The current parameters include current values. Determining that the current parameters meet the preset dry-burning conditions includes: obtaining the bottom temperature of the electromagnetic cooking appliance; if the current value is greater than the preset current threshold when the bottom temperature is greater than or equal to a second preset temperature threshold, then it is determined that the preset dry-burning conditions are met.

5. The method according to any one of claims 1-4, characterized in that, When it is determined that the electromagnetic cooking appliance is in a dry-burning state, the method further includes: controlling the electromagnetic cooking appliance to stop heating.

6. The method according to claim 2 or 4, characterized in that, The current value includes the high-frequency current value and / or low-frequency current value of the electromagnetic cooking appliance; the current change rate includes the high-frequency current change rate and / or low-frequency current change rate of the electromagnetic cooking appliance.

7. The method according to claim 4, characterized in that, If the preset dry-burning conditions are met, the method further includes: controlling the electromagnetic cooking appliance to heat intermittently at a preset power; if the current value is still greater than the preset current threshold after a preset time, then the electromagnetic cooking appliance is determined to be in a dry-burning state.

8. A controller, characterized in that, include: The device includes a memory, a processor, and a program stored in the memory and executable on the processor, wherein when the processor executes the program, it implements the dry-burn detection method for an electromagnetic cooking appliance according to any one of claims 1-7.

9. A dry-burn detection device for an electromagnetic cooking appliance, characterized in that, The device includes: a detection module for acquiring current parameters during the heating process of the electromagnetic cooking appliance; and a determination module for determining that the electromagnetic cooking appliance is in a dry-burning state when the current parameters meet preset dry-burning conditions.

10. A computer-readable storage medium, characterized in that, It stores a dry-burn detection program for an electromagnetic cooking appliance, which, when executed by a processor, implements the dry-burn detection method for an electromagnetic cooking appliance according to any one of claims 1-7.

11. An electromagnetic cooking appliance, characterized in that, The invention includes a memory, a processor, and a dry-burn detection program for an electromagnetic cooking appliance stored in the memory and executable on the processor. When the processor executes the dry-burn detection program for the electromagnetic cooking appliance, it implements the dry-burn detection method for the electromagnetic cooking appliance according to any one of claims 1-7.

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