Abnormal sound control method and device of electromagnetic heating equipment and electromagnetic heating equipment

Abstract

The invention discloses an abnormal sound control method and device of electromagnetic heating equipment and the electromagnetic heating equipment, and relates to the technical field of the electromagnetic heating equipment. The abnormal sound control method of the electromagnetic heating equipment comprises the following steps: acquiring a target power supply input frequency, a target power supply input voltage and a target on / off time sequence of a switching device; according to the obtained target power supply input frequency and target power supply input voltage, determining a zero crossing point moment of the target power supply half-wave duration; when the cookware is detected and heating is started, the switching device is controlled to work, the first turn-on duration of the switching device in each turn-on / turn-off period is gradually prolonged until the zero crossing point moment of the target power supply half-wave duration is reached, and the switching device is controlled to be turned on / off according to the target turn-on / turn-off time sequence; according to the technical scheme, the problem that in the prior art, due to the fact that a switching device is directly driven under the high-voltage condition, the cooker generates obvious abnormal sound can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic heating devices, and particularly to a method and device for controlling abnormal noise of an electromagnetic heating device and an electromagnetic heating device. Background Art

[0002] During the operation of an electromagnetic heating device, the 220V mains power is converted into a 310V DC bus voltage after rectification and filtering. Some electromagnetic heating devices on the market do not use soft start technology when detecting a cookware and starting up, but directly drive the IGBT under high voltage conditions, which will cause obvious abnormal noise on the cookware. Summary of the Invention

[0003] The main object of the present invention is to provide a method and device for controlling abnormal noise of an electromagnetic heating device and an electromagnetic heating device, aiming to solve the problem that obvious abnormal noise is generated on the cookware due to directly driving a switching device under high voltage conditions in the prior art.

[0004] To achieve the above object, the present invention provides a method for controlling abnormal noise of an electromagnetic heating device, where the electromagnetic heating device includes a switching device, and the method for controlling abnormal noise of the electromagnetic heating device includes: Obtain the target power supply input frequency, target power supply input voltage, and target on / off timing of the switching device; Determine the zero-crossing moment of the target power supply half-wave duration according to the obtained target power supply input frequency and target power supply input voltage; When detecting a cookware and starting heating, control the switching device to work and gradually extend the first on-time in each on / off cycle of the switching device until the zero-crossing moment of the target power supply half-wave duration, and control the switching device to turn on / off according to the target on / off timing.

[0005] In an embodiment, the method for controlling abnormal noise of the electromagnetic heating device further includes: When stopping heating, extend the second on-time of the switching device according to the target power supply half-wave duration until the zero-crossing moment of the target power supply half-wave duration, and control the switching device to turn off.

[0006] In an embodiment, the step of determining the zero-crossing moment of the target power supply half-wave duration according to the obtained target power supply input frequency and target power supply input voltage specifically includes: Obtain the target power supply input frequency, target power supply input voltage, a preset frequency factor, and a preset voltage factor; Determine a target frequency influence coefficient according to the target power supply input frequency and the preset frequency factor, and determine a target voltage influence coefficient according to the target power supply input voltage and the preset voltage factor; Determine the zero-crossing moment of the target power supply half-wave duration according to the target frequency influence coefficient and the target voltage influence coefficient.

[0007] In one embodiment, the step of obtaining the target power supply input frequency, the target power supply input voltage, and the target on / off timing of the switching device further includes: Obtain a preset first turn-on duration; The step of, when detecting a cookware and starting heating, controlling the switching device to operate and gradually extending the first turn-on duration in each on / off cycle of the switching device until, at the zero-crossing moment of the target power supply half-wave duration, controlling the switching device to turn on / off according to the target on / off timing specifically includes: When detecting a cookware and starting heating, control the switching device to turn on for a preset first turn-on duration; After the switching device is turned on for a preset first turn-on duration, gradually extend the first turn-on duration in each on / off cycle of the switching device until, at the zero-crossing moment of the target power supply half-wave duration, control the switching device to turn on / off according to the target on / off timing.

[0008] In one embodiment, the electromagnetic heating device further includes a resonant circuit, and the resonant circuit includes a resonant capacitor and a wire coil. The step of obtaining the preset first turn-on duration specifically includes: Obtain the capacitance value of the resonant capacitor, the inductance value of the wire coil, and the turn-on voltage of the switching device; Based on the capacitance value of the resonant capacitor, the inductance value of the wire coil, and the turn-on voltage of the switching device, perform parameter debugging to determine the preset first turn-on duration.

[0009] In one embodiment, the abnormal sound control method of the electromagnetic heating device further includes: According to the material of the cookware, adjust the third turn-on duration, the turn-on interval, or the period of the switching device.

[0010] In one embodiment, the electromagnetic heating device further includes a resonant circuit; the step of, according to the material of the cookware, adjusting the third turn-on duration of the switching device specifically includes: Obtain the resonant amplitude of the resonant circuit; According to the resonant amplitude of the resonant circuit, adjust the third turn-on duration of the switching device until, at the zero-crossing moment of the target power supply half-wave duration, control the turn-on voltage of the switching device to drop to zero.

[0011] In one embodiment, the resonant amplitude of the resonant circuit is negatively correlated with the third turn-on duration of the switching device.

[0012] In one embodiment, the step of adjusting the third turn-on duration of the switching device according to the resonance amplitude of the resonance circuit until the turn-on voltage of the switching device is reduced to zero at the zero-crossing moment of the target power supply half-wave duration specifically includes: When it is determined that the resonance amplitude of the resonance circuit is not greater than the first preset resonance amplitude, increase the third turn-on duration of the switching device until the turn-on voltage of the switching device is reduced to zero at the zero-crossing moment of the target power supply half-wave duration; When it is determined that the resonance amplitude of the resonance circuit is greater than the first preset resonance amplitude, decrease the third turn-on duration of the switching device until the turn-on voltage of the switching device is reduced to zero at the zero-crossing moment of the target power supply half-wave duration.

[0013] In one embodiment, the step of adjusting the turn-on interval of the switching device according to the material of the cookware specifically includes: When it is determined that the resonance amplitude of the resonance circuit reaches the second preset resonance amplitude, control the switching device to turn on to adjust the turn-on interval of the switching device; Wherein, the second preset resonance amplitude is less than the first preset resonance amplitude.

[0014] In one embodiment, the abnormal noise control method of the electromagnetic heating device further includes: Obtain the turn-on voltage of the switching device; When it is determined that the first turn-on duration of the switching device reaches the zero-crossing moment of the target half-wave duration and the turn-on voltage of the switching device reaches the preset turn-on voltage, stop extending the first turn-on duration in each on / off cycle of the switching device, and control the switching device to turn on / off according to the target on / off timing.

[0015] The present invention also provides an abnormal noise control device, including: A memory; A processor, an abnormal noise control program of the electromagnetic heating device stored on the memory and executed by the processor, and when the abnormal noise control program is executed by the processor, the abnormal noise control method of the electromagnetic heating device as described above is implemented.

[0016] The present invention also provides an electromagnetic heating device, including the abnormal noise control device as described above.

[0017] The technical solution of the present invention obtains the target power supply input frequency and the target power supply input voltage, and determines the zero-crossing moment of the half-wave duration of the target power supply accordingly. When a cookware is detected and heating is started, the switching device is controlled to operate and the on-time in each on / off cycle is gradually extended, so as to achieve a smooth increase in power, rather than directly applying a high power at the start moment. This can effectively avoid the voltage peak in the startup stage of the electromagnetic heating device, make the working current of the device increase gradually, and reduce the vibration and abnormal noise of the cookware caused by the sudden change of the magnetic field. After reaching the zero-crossing moment of the half-wave duration of the target power supply, the switching device is controlled to turn on / off according to the preset target on / off timing sequence. This method enables the switching device to operate only with a short on-time at the initial stage of the device startup, and then gradually extends it to the on-time required for normal operation, thus avoiding the electromagnetic shock and mechanical vibration caused by the sudden change of current at the start moment, and effectively suppressing the abnormal noise generated by the pulsation of the electromagnetic force during the startup process of the cookware. The present invention can solve the problem that the cookware generates obvious abnormal noise due to directly driving the switching device under high voltage conditions in the prior art, and significantly improve the operation stability and working reliability of the electromagnetic heating device during the startup process. Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following-described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0019] Figure 1 It is a flowchart of the first embodiment of the abnormal noise control method for the electromagnetic heating device provided by the present invention; Figure 2 It is a curve comparison diagram of the target power supply input voltage and the working voltage of the wire coil of the electromagnetic heating device provided by the present invention changing with the running time; Figure 3 It is a flowchart of the second embodiment of the abnormal noise control method for the electromagnetic heating device provided by the present invention; Figure 4 It is a flowchart of the third embodiment of the abnormal noise control method for the electromagnetic heating device provided by the present invention; Figure 5 It is a flowchart of the fourth embodiment of the abnormal noise control method for the electromagnetic heating device provided by the present invention; Figure 6 It is a flowchart of the fifth embodiment of the abnormal noise control method for the electromagnetic heating device provided by the present invention; Figure 7 It is a flowchart of the sixth embodiment of the abnormal noise control method for the electromagnetic heating device provided by the present invention; Figure 8 Flow chart of the seventh embodiment of the abnormal noise control method for the electromagnetic heating device provided by the present invention; Figure 9 Flow chart of the eighth embodiment of the abnormal noise control method for the electromagnetic heating device provided by the present invention; Figure 10 Flow chart of the ninth embodiment of the abnormal noise control method for the electromagnetic heating device provided by the present invention; Figure 11 Flow chart of the tenth embodiment of the abnormal noise control method for the electromagnetic heating device provided by the present invention; Figure 12 Schematic diagram of the circuit function modules of an embodiment of the abnormal noise control device provided by the present invention; Figure 13 Schematic diagram of the circuit function modules of an embodiment of the electromagnetic heating device provided by the present invention.

[0020] Explanation of the reference numerals in the drawings: 100, electromagnetic heating device; 1, abnormal noise control device; 11, memory; 12, processor; 2, rectification and filtering circuit; 3, panel; 4, wire coil; 5, switching device.

[0021] The realization, functional features and advantages of the object of the present invention will be further described in conjunction with the embodiments with reference to the accompanying drawings. Detailed implementation manners

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0023] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present invention, the directional indications are only used to explain the relative position relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0024] In addition, if the descriptions such as "first" and "second" are involved in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, if "and / or" or "and / or" appears throughout the text, its meaning includes three parallel scenarios. Taking "A and / or B" as an example, it includes Scenario A, or Scenario B, or the scenario where both A and B are satisfied simultaneously. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0025] During the operation of the electromagnetic heating device, the 220V mains power is rectified and filtered and then converted into a 310V DC bus voltage. When some electromagnetic heating devices on the market detect cookware and start, they do not use soft start technology but directly drive the IGBT under high voltage conditions, which will cause obvious abnormal noises on the cookware.

[0026] To solve the above problems, the present invention proposes a method for controlling abnormal noises of an electromagnetic heating device 100.

[0027] Please refer to Figure 1 、 Figure 2 and Figure 13 In an embodiment of the present invention, the electromagnetic heating device 100 includes a switching device 5, and the method for controlling abnormal noises of the electromagnetic heating device 100 includes: S100A. Obtain the target power input frequency, the target power input voltage, and the target on / off timing of the switching device; S200. Determine the zero-crossing moment of the target power half-wave duration according to the obtained target power input frequency and target power input voltage; S300. When detecting cookware and starting heating, control the switching device to work and gradually extend the on-time duration in each on / off cycle of the switching device 5 until, at the zero-crossing moment of the target power half-wave duration, control the switching device to turn on / off according to the target on / off timing.

[0028] In this embodiment, the electromagnetic heating device 100 can be an induction cooker, a cooking device, a cooking robot, etc., and is not specifically limited. The electromagnetic heating device 100 mainly includes a switching device 5, but it does not mean that its structure is only composed of the switching device 5. It can also be further integrated with relevant components such as a rectifier filter circuit 2, a panel 3, a coil disk 4, etc. according to actual needs. For the convenience of description, the following takes the electromagnetic heating device 100 including a rectifier filter circuit 2, a panel 3, a switching device 5, and a coil disk 4 as an example to elaborate on its hardware structure and working principle in detail: The rectifier filter circuit 2 is used to convert the externally input mains power into stable direct current; the panel 3 is not only used to place cookware, but also can realize interaction operations with users; the switching device 5 is used to convert the direct current output by the rectifier filter circuit 2 into high-frequency alternating current; the coil disk 4 is used to generate a high-frequency alternating magnetic field when the high-frequency alternating current passes through. In practical applications, when the electromagnetic heating device 100 works, the mains power (such as 220V alternating current) first passes through the rectifier filter circuit 2 and is converted into a direct current voltage. Since the rectified voltage is processed by capacitor filtering and the like, a direct current voltage slightly higher than the peak value of the original alternating current voltage can be obtained. For 220V mains power, this value is approximately 310V, which is the so-called DC bus voltage. Then, the switching device 5 is used to convert this DC bus voltage into a high-frequency alternating voltage. When the high-frequency alternating current passes through the coil disk 4, a high-frequency alternating magnetic field is generated. When a cookware made of ferromagnetic material is placed on the panel 3, under the action of the high-frequency alternating magnetic field, the bottom of the pot will cut the magnetic force lines to generate an induced current. According to the eddy current effect, these induced currents will form heat energy at the bottom of the pot, thereby realizing the heating of food.

[0029] However, some electromagnetic heating devices 100 on the market currently do not adopt soft start technology when detecting cookware and starting up. Soft start is a technology that realizes the smooth start of a device by gradually increasing the input voltage. It is mainly used to avoid damage to the circuit components of the device due to sudden increase in current at the moment of startup, and also helps to reduce electromagnetic noise and mechanical vibration. If the electromagnetic heating device 100 does not use soft start technology but directly drives the switching device 5 under high voltage conditions when detecting cookware and starting up, it will cause the current in the coil disk 4 to rise rapidly. This rapidly changing current will cause a rapid fluctuation in the magnetic field strength, resulting in a drastic change in the eddy current generated at the bottom of the pot, and may further cause mechanical vibration of the cookware and emit obvious abnormal sounds. This is because the cookware made of metal material will undergo minute physical deformations under the action of a high-intensity and rapidly changing high-frequency alternating magnetic field, and the vibration effects caused by these physical deformations will accumulate to form sounds audible to the human ear.

[0030] In response to the above challenges, the present invention proposes a method for controlling abnormal noise of an electromagnetic heating device 100, aiming to solve the problem that obvious abnormal noise is generated in the cookware due to directly driving the switching device 5 under high voltage conditions in the prior art. In this embodiment, the method for controlling abnormal noise of the electromagnetic heating device 100 realizes the control of the switching device 5 through the following three steps, so as to reduce the abnormal noise generated by the electromagnetic heating device 100 during startup and improve the stability of the electromagnetic heating device 100. First, in step S100A, the electromagnetic heating device 100 obtains the target power supply input frequency, the target power supply input voltage, and the target on / off timing of the switching device 5, which serve as the basis for subsequent control. Among them, the target power supply can be the mains power, a mobile power supply, or other power supplies. The target power supply in this embodiment mainly refers to the mains power. Correspondingly, the target power supply input frequency is the standard frequency of the power system accessed by the electromagnetic heating device 100 during use. There are differences in the standard frequencies adopted in different countries or regions. Most countries use 50 Hz or 60 Hz as the standard frequency of their power systems. The target power supply input voltage refers to the value of the AC voltage accessed by the electromagnetic heating device 100, and this value also varies from country to country and region to region. For example, the household electricity voltage in some countries is 120V (single-phase) or 240V (split-phase), while the standard voltage of household electricity in another part of the countries is 230V.

[0031] Next, in step S200, based on the acquired target power input frequency and target power input voltage, the target power half-wave duration and the voltage zero-crossing moment of the target power half-wave duration are determined. Since there are differences in the mains input voltage and frequency in different countries, the actual input voltage range is generally 100V~240V, and the frequency range is usually 40Hz~60Hz. In this context, the higher the input voltage, the "higher" the zero-crossing point determined by the software; the faster the input frequency, the faster the appearance speed of the software zero-crossing point. Here, the "software zero-crossing point" refers to the moment when the current or voltage of the coil 4 in the electromagnetic heating device 100 is converted from the positive half-cycle to the negative half-cycle, or from the negative half-cycle to the positive half-cycle, as recognized by the internal software algorithm of the electromagnetic heating device 100. For alternating current, the zero-crossing point is the moment when the voltage or current waveform of the coil 4 crosses the zero value within one cycle. In a complete sine wave cycle, the zero-crossing phenomenon occurs once every half cycle. Specifically, for alternating current with an input frequency of 50Hz, its complete cycle is 20ms, so the zero-crossing point appears approximately every 10ms; for alternating current with a frequency of 60Hz, the complete cycle is 16.67ms, and the zero-crossing point appears approximately every 8.33ms. It can be seen that the software zero-crossing point changes with the change of the mains input voltage and / or frequency. Therefore, the abnormal sound control method of this embodiment ensures that the switching device 5 can be turned on or off at the real zero-crossing point by obtaining the accurate target power input frequency and voltage, and calculating the corresponding target half-wave duration and its zero-crossing moment, thereby effectively reducing the abnormal sound caused by the switching action and improving the operation stability of the electromagnetic heating device 100.

[0032] Finally, in step S300, when the electromagnetic heating device 100 detects that the cookware has been placed on the panel 3 of the electromagnetic heating device 100 and starts to heat, the electromagnetic heating device 100 controls the switching device 5 to work and gradually extends the on-time in each on / off cycle of the switching device 5. This process continues until at the zero-crossing moment of the target power half-wave duration, the on and off of the switching device 5 can be accurately controlled according to the preset target on / off timing sequence. Specifically, the switching device 5 can be turned on and then turned off in the first on / off cycle with a preset first on-time (such as 2μs). When entering the second on / off cycle, the on-time of the current cycle can be appropriately extended based on the first on / off cycle, for example, from 2μs to 3μs, or even further extended to 4μs, etc., and the specific value is not limited. By increasing the on-time cycle by cycle, finally, the switching device 5 can perform the on or off operation according to the target on / off timing sequence at the zero-crossing moment of the target power half-wave duration. If the switching device 5 is turned on at this zero-crossing moment, it will run according to the set on-time in the target on / off timing sequence and then turn off; conversely, if the switching device 5 is turned off at this zero-crossing moment, it will run according to the set off-time in the target on / off timing sequence and then turn on.

[0033] However, from Figure 2 it can be found that no matter which on / off cycle the switching device 5 operates in, when the switching device 5 is turned on, the current in the wire coil 4 starts to increase from zero. Due to the inductance of the wire coil 4, the current cannot change instantaneously but rises at a certain slope. When the switching device 5 is turned off, the current in the wire coil 4 continues to flow through the freewheeling diode circuit and gradually decreases to zero. Through this control method, the current in the wire coil 4 can increase or decrease smoothly with the operation of the switching device 5, specifically increasing smoothly when the switching device 5 is turned on and decreasing smoothly when the switching device 5 is turned off, thereby avoiding the abnormal noise generated due to the sharp change of the current in the wire coil 4 during the startup process of the electromagnetic heating device 100 and improving the overall performance and user experience of the electromagnetic heating device 100.

[0034] The technical solution of the present invention obtains the target power supply input frequency and the target power supply input voltage, and determines the zero-crossing moment of the half-wave duration of the target power supply accordingly. When a cookware is detected and heating is started, the switching device 5 is controlled to operate and the on-time in each on / off cycle is gradually extended, so as to achieve a smooth increase in power instead of directly applying a high power at the startup moment. This can effectively avoid the voltage peak during the startup stage of the electromagnetic heating device 100, make the working current of the device increase gradually, and reduce the vibration and abnormal noise of the cookware caused by the sudden change of the magnetic field. After reaching the zero-crossing moment of the half-wave duration of the target power supply, the switching device 5 is controlled to turn on / off according to the preset target on / off timing sequence. This method enables the switching device 5 to operate only with a short on-time at the initial stage of device startup and then gradually extend it to the on-time required for normal operation, thereby avoiding the electromagnetic shock and mechanical vibration caused by current mutation at the startup moment and effectively suppressing the abnormal noise generated by the pulsation of the electromagnetic force of the cookware during the startup process. The present invention can solve the problem that the cookware generates obvious abnormal noise due to directly driving the switching device 5 under high voltage conditions in the prior art, and significantly improve the operation stability and working reliability of the electromagnetic heating device 100 during the startup process.

[0035] In the prior art, when the electromagnetic heating device 100 stops heating, if the switching device 5 is not turned off at the current zero-crossing point, it will cause a sharp change in the magnetic field due to the suddenly interrupted current, which will in turn cause the cookware to vibrate mechanically and generate noise. To solve this problem, please refer to Figure 3 , in an embodiment, the abnormal noise control method of the electromagnetic heating device 100 further includes: S400. When stopping heating, extend the second on-time of the switching device according to the half-wave duration of the target power supply until, at the zero-crossing moment of the half-wave duration of the target power supply, control the switching device to turn off.

[0036] In this embodiment, in step S400, when the electromagnetic heating device 100 stops heating the cookware on the panel 3, the switching device 5 is not immediately turned off. Instead, according to the previously determined target power supply half-wave duration, the second conduction duration of the switching device 5 is extended until the voltage or current zero-crossing moment of the target power supply half-wave duration, and then the switching device 5 is controlled to turn off with a delay. By turning off with a delay, the turn-off timing of the switching device 4 is actually adjusted to avoid sudden disconnection at non-zero-crossing moments. Because directly turning off the switching device 5 at non-zero-crossing moments will cause the current in the coil 4 to quickly interrupt, resulting in a sharp change in the magnetic field intensity. This rapid change may not only cause mechanical vibration of the cookware but also generate obvious noise. On the contrary, by extending the second conduction duration, the turn-off action of the switching device 5 can occur exactly at the zero-crossing moment when the voltage or current is close to zero, ensuring that the current in the coil 4 can naturally decay to near zero before being cut off, avoiding the negative impacts brought by current mutation.

[0037] For easy understanding, the following is an example to illustrate this: Assume that the determined target power supply half-wave duration is 10 ms, that is, the complete cycle is 20 ms. In general, the switching device 5 may turn off at 18 ms or 19 ms, or even other non-zero-crossing moments, rather than at the zero-crossing moment of 20 ms. This early turn-off will cause the current in the coil 4 to mutate due to the rapid turn-off of the switching device 5, resulting in violent fluctuations in the magnetic field and generating abnormal noise. To avoid this problem, in this embodiment, the turn-off of the switching device 5 is achieved by extending the second conduction duration of the switching device 5 in the current on / off cycle. For example, if the originally set second conduction duration is 2 μs, it can be extended to 3 μs as needed; if this duration is still not sufficient for the switching device 5 to complete the turn-off at the zero-crossing moment of the target power supply half-wave duration, that is, the switching device 5 fails to turn off at the zero-crossing moment of 20 ms, it can be further extended to 4 μs, and so on for adjustment. In this way, it can be ensured that the current in the coil 4 has enough time to gradually decay to near zero value near the next zero-crossing moment, avoiding the sharp change in the magnetic field caused by sudden interruption of the current. In this way, not only can the mechanical vibration and noise of the cookware caused by magnetic field mutation be reduced, but also the smoothness and safety of the operation of the electromagnetic heating device 100 can be improved, further optimizing the user experience. In other words, the abnormal noise control method provided in this embodiment can solve the abnormal noise problem that may be caused by improper turn-off timing of the switching device 5 during the heating stop process of the electromagnetic heating device 100, enhancing the operation reliability of the electromagnetic heating device 100.

[0038] Please refer to Figure 4 , in one embodiment, step S200 specifically includes: S210. Obtain the target power supply input frequency, the target power supply input voltage, the preset frequency factor, and the preset voltage factor; S220. Determine a target frequency influence coefficient according to the target power supply input frequency and a preset frequency factor, and determine a target voltage influence coefficient according to the target power supply input voltage and a preset voltage factor; S230. Determine the zero-crossing moment of the half-wave duration of the target power supply according to the target frequency influence coefficient and the target voltage influence coefficient.

[0039] It can be understood that during the production process of the electromagnetic heating device 100, production personnel can fit a first correlation function based on the influence of the mains input frequency on the half-wave duration of the mains of the electromagnetic heating device 100. Specifically, by conducting experiments on different mains input frequencies from 40 Hz to 60 Hz, the first mains half-wave duration of the electromagnetic heating device 100 corresponding to each mains input frequency is obtained, and based on multiple groups of mains input frequencies and the corresponding first mains half-wave durations, the first correlation function is fitted. The first correlation function can be a linear relationship or a non-linear relationship. From the first correlation function, a preset frequency factor can be extracted and stored in the electromagnetic heating device 100. Similarly, production personnel can also fit a second correlation function based on the influence of the mains input voltage on the half-wave duration of the mains of the electromagnetic heating device 100. That is, by adjusting the mains input voltage within the range of 100 V to 270 V, the second mains half-wave duration corresponding to each mains input voltage is obtained, and based on multiple groups of mains input voltages and the corresponding second mains half-wave durations, the second correlation function is fitted. The second correlation function can also be a linear or non-linear relationship, and a preset voltage factor can be extracted from it and stored in the electromagnetic heating device 100.

[0040] In this embodiment, step S200 is used to determine the zero-crossing moment of the half-wave duration of the target power supply, and specifically includes the following three steps: First, in step S210, the electromagnetic heating device 100 acquires the target power supply input frequency, the target power supply input voltage, a preset frequency factor, and a preset voltage factor, where the preset voltage factor includes a first preset voltage factor and a second preset voltage factor. These parameters are the basis for calculating the zero-crossing moment of the half-wave duration of the target power supply. As can be seen from the above, the preset frequency factor, the first preset voltage factor, and the second preset voltage factor are adjustment coefficients preset according to different mains conditions, and their function is to compensate for the software judgment deviation caused by the change of the actual mains input. Next, in step S220, the electromagnetic heating device 100 determines the target frequency influence coefficient based on the acquired target power supply input frequency and the preset frequency factor, and its expression is: target frequency influence coefficient = (preset input frequency - target power supply input frequency) × preset frequency factor. If 50 Hz is used as the preset input frequency, the formula is specifically: target frequency influence coefficient = (50 - target power supply input frequency) × preset frequency factor. At the same time, the electromagnetic heating device 100 also uses the target power supply input voltage and the preset voltage factor to determine the target voltage influence coefficient, and its expression is: target frequency influence coefficient = (target input voltage - preset input voltage) × first preset voltage factor + second preset voltage factor. If 230 V is used as the preset input voltage, the formula is specifically: target frequency influence coefficient = (target input voltage - 230) × first preset voltage factor + second preset voltage factor. In fact, the purpose of steps S210 and S220 is to quantify the influence of different mains input frequencies and mains input voltages on the zero-crossing moment calculated by the electromagnetic heating device 100, so as to ensure that the calculation result is as close as possible to the real voltage or current zero-crossing. Finally, in step S230, the above-determined target frequency influence coefficient and target voltage influence coefficient are summed to obtain the zero-crossing moment of the half-wave duration of the target power supply. By this method, the electromagnetic heating device 100 can calculate the zero-crossing moment of the half-wave duration of the target power supply, so that the switching device 5 can be turned on or off at the most appropriate time (i.e., close to the actual zero-crossing), thereby effectively reducing the electromagnetic noise and mechanical vibration caused by non-zero-point operation, and improving the stability and user experience of the operation of the electromagnetic heating device 100. That is, the method provided in this embodiment can not only solve the problems caused by the mismatch between the software zero-crossing and the actual zero-crossing in the traditional method, but also enhance the overall performance of the electromagnetic heating device 100.

[0041] Please refer to Figure 5 , in one embodiment, in step S100A, it further includes: S100B. Acquire the preset first turn-on duration; In this embodiment, step S100A includes, in addition to obtaining the target power input frequency, the target power input voltage, and the target on / off timing of the switching device 5, step S100B, that is, obtaining a preset initial turn-on duration, which is used as the initial turn-on duration for controlling the switching device 5 to turn on at the initial stage of the electromagnetic heating device 100. Optionally, the preset initial turn-on duration is not less than 2 μs and not more than 5 μs. By limiting the preset initial turn-on duration within this range, the rising rate of the current in the coil 4 can be effectively limited at the initial stage of the start-up of the electromagnetic heating device 100, avoiding insufficient power caused by too short a turn-on time or current impact caused by too long a turn-on time, thereby achieving smooth soft start.

[0042] Step S300 specifically includes: S310. When a cookware is detected and heating is started, control the switching device to turn on for the preset initial turn-on duration; S320. After the switching device is turned on for the preset initial turn-on duration, gradually extend the first turn-on duration in each on / off cycle of the switching device until, at the zero-crossing moment of the target power half-wave duration, control the switching device to turn on / off according to the target on / off timing.

[0043] In this embodiment, first, in step S310, when the electromagnetic heating device 100 detects a cookware and starts heating, the electromagnetic heating device 100 first controls the switching device 5 to turn on for the preset initial turn-on duration, thereby avoiding applying too high energy at the beginning, preventing the sudden increase of the current in the coil 4, and further reducing the generation of impact and abnormal noise. Subsequently, in step S320, after the first turn-on is completed, the electromagnetic heating device 100 gradually extends the first turn-on duration of the switching device 5 in each on / off cycle according to the actual operating state. By means of increasing cycle by cycle, the current in the coil 4 can rise or fall smoothly along with the operation of the switching device 5, thereby realizing the gradual increase of the output power of the electromagnetic heating device 100. This process continues until finally, at the voltage or current zero-crossing moment of the target power half-wave duration, the switching device 5 can be turned on or off according to the preset target on / off timing. Through this control method, the switching device 5 can always work within a time window close to the actual zero-crossing point during the start-up stage of the entire electromagnetic heating device 100, effectively suppressing the electromagnetic noise and mechanical vibration caused by non-zero-crossing turn-on, improving the smoothness and safety of the operation of the electromagnetic heating device 100, and further optimizing the user experience.

[0044] Please refer to Figure 6 , in an embodiment, the electromagnetic heating device 100 further includes a resonant circuit. The resonant circuit includes a resonant capacitor and the coil 4. Step S100B specifically includes: S110B. Obtain the capacitance value of the resonant capacitor, the inductance value of the coil, and the turn-on voltage of the switching device; S120B. Perform parameter debugging based on the capacitance value of the resonant capacitor, the inductance value of the wire coil, and the turn-on voltage of the switching device to determine the preset first turn-on duration.

[0045] In this embodiment, first, in step S110B, the electromagnetic heating device 100 obtains the capacitance value of the resonant capacitor, the inductance value of the wire coil 4, and the turn-on voltage of the switching device 5. Then, in step S120B, parameter debugging is performed based on the obtained capacitance value of the resonant capacitor, the inductance value of the wire coil 4, and the turn-on voltage of the switching device 5, so as to determine the preset first turn-on duration of the switching device 5. The core purpose of this process is to ensure that the electromagnetic heating device 100 can operate safely, stably, and efficiently in the initial startup stage, while minimizing electromagnetic noise and mechanical vibration. Specifically, from the relationship formula of the resonant frequency ( is the resonant frequency of the resonant circuit, L is the inductance value of the wire coil 4, and C is the capacitance value of the resonant capacitor), it can be seen that the capacitance value of the resonant capacitor and the inductance value of the wire coil 4 jointly determine the operating frequency and resonant characteristics of the electromagnetic heating device 100, thereby affecting the rising speed and amplitude of the current in the initial startup stage; while the turn-on voltage of the switching device 5 directly affects the voltage level applied to the wire coil 4 and the resulting current magnitude. If the first turn-on duration of the switching device 5 is set unreasonably, for example, the turn-on time is too long, it may cause too high an initial current or voltage in the wire coil 4, thereby causing obvious electromagnetic noise and mechanical vibration of the cookware, and even increasing the switching loss of the switching device 5; while the turn-on time is too short, it may result in insufficient power output, unable to effectively establish a magnetic field, and affecting the heating efficiency. Therefore, in this embodiment, by comprehensively considering the specific capacitance value of the resonant capacitor, the inductance value of the wire coil 4, and the turn-on voltage of the switching device 5, and performing parameter debugging on them, the optimal preset first turn-on duration can be determined. This duration can not only avoid insufficient power of the electromagnetic heating device 100 caused by too short a first turn-on duration of the switching device 5, but also prevent current impact caused by too long a first turn-on duration of the switching device 5, thereby ensuring that the energy input by the electromagnetic heating device 100 at the moment of startup can avoid mechanical vibration and electromagnetic noise caused by too high initial energy, and at the same time ensure sufficient power output to quickly establish a stable high-frequency alternating magnetic field, achieving a fast and efficient heating response. In addition, by reasonably matching and optimizing the debugging of the above parameters, the service life of the electromagnetic heating device 100 can be effectively extended, unnecessary energy consumption can be reduced, and its operating stability and reliability can be improved.

[0046] Please refer to Figure 7 , in one embodiment, the abnormal sound control method of the electromagnetic heating device 100 further includes: S500. Adjust the third turn-on duration, turn-on interval, or period of the switching device according to the material of the cookware.

[0047] It can be understood that since cookware made of different materials has different impacts on the electromagnetic heating device 100, especially its equivalent impedance changes with the magnetic conductivity and electrical conductivity of the material, which directly affects the working state of the resonant circuit. Therefore, in step S500 of this embodiment, the electromagnetic heating device 100 can adjust at least one of the third turn-on duration, turn-on interval, and period of the switching device 5 according to the material of the cookware to achieve more refined control and effectively suppress abnormal noises. Specifically, the soft start interval is defined as the time from the moment when the switching device 5 is first turned on to the zero-crossing moment of the target power supply half-wave duration. The third turn-on duration refers to the total turn-on duration of the switching device 5 within this interval, the turn-on interval is the time interval between two consecutive turn-on moments of the switching device 5 within this interval, and the period refers to the duration required for the switching device 5 to complete a complete turn-on and turn-off process within this interval.

[0048] Specifically, after the switching device 5 is first turned on, the electromagnetic heating device 100 can obtain the resonant amplitude and frequency of the resonant circuit in real time. If the voltage resonance drop amplitude of the resonant circuit after the first turn-on is small, it indicates that the equivalent impedance of the cookware is large and it may be made of a non-magnetic material with low resistivity. In this case, the electromagnetic heating device 100 can extend the third turn-on duration, for example, increase the first turn-on duration in the current on / off cycle, ensure sufficient energy transfer, and maintain efficient heating; at the same time, it can also appropriately reduce the turn-on interval of the switching device 5, or proportionally increase the period of the switching device 5 to make the energy injection more intensive and further improve the heating efficiency and stability. On the contrary, if the resonant amplitude drops significantly, it indicates that the equivalent impedance of the cookware is small and it may be made of a material with high resistivity or high magnetic conductivity. At this time, the third turn-on duration can be correspondingly shortened, such as reducing the first turn-on duration in the current on / off cycle, to avoid excessive magnetic field fluctuations caused by large current changes and thus reduce the risk of abnormal noises; at the same time, the turn-on interval of the switching device 5 can also be appropriately increased, or the period of the switching device 5 can be proportionally reduced to make the energy injection moderate and prevent unnecessary noises caused by excessive energy input. In this way, the electromagnetic heating device 100 can adaptively adjust at least one of the third turn-on duration, turn-on interval, or period of the switching device 5 according to the different materials of the cookware, ensure that the switching device 5 can be turned on near the voltage zero-crossing point, and accelerate the process of the turn-on voltage dropping to zero. In this way, not only can the heating efficiency be improved, but also the noise level during the start-up process can be reduced, enhancing the stability of the device operation and the user experience.

[0049] Please refer to Figure 8 , in an embodiment, the electromagnetic heating device 100 further includes a resonant circuit; the step of adjusting the second turn-on duration of the switching device 5 according to the material of the cookware specifically includes: S510A. Obtain the resonant amplitude of the resonant circuit; S520A. Adjust the third turn-on duration of the switching device according to the resonance amplitude of the resonant circuit until the turn-on voltage of the switching device is reduced to zero at the zero-crossing moment of the target power supply half-wave duration.

[0050] In this embodiment, the electromagnetic heating device 100 further includes a resonant circuit. In order to optimize the heating process according to the cookware material and reduce abnormal noise, step S500 can be refined into two steps to adjust the third turn-on duration of the switching device 5. First, in step S510A, the electromagnetic heating device 100 obtains the resonance amplitude of the resonant circuit. The resonance amplitude can reflect the influence of the cookware material on the electromagnetic heating process, especially the change of the equivalent impedance of the cookware. Then, in step S520A, based on the obtained resonance amplitude, the third turn-on duration of the switching device 5 is adjusted to ensure that the turn-on voltage of the switching device 5 can be controlled to drop to zero at the zero-crossing moment of the target power supply half-wave duration. Specifically, if it is detected that the resonance amplitude is small, it means that the equivalent impedance of the cookware is large, and the third turn-on duration can be extended to ensure sufficient energy transfer; on the contrary, if the resonance amplitude is large, it indicates that the equivalent impedance of the cookware is small, and the third turn-on duration can be shortened to avoid sudden current changes causing violent fluctuations in the magnetic field and potential abnormal noise problems. Through this method of this embodiment, not only can the electromagnetic heating device 100 smoothly transition from the startup stage to the stable operating state, but also the switching device 5 can be turned on or off when approaching the voltage zero-crossing point, thereby effectively reducing the noise level.

[0051] Please refer to Figure 8 , in one embodiment, the resonance amplitude of the resonant circuit has a negative correlation with the third turn-on duration of the switching device 5.

[0052] In this embodiment, the resonance amplitude of the resonant circuit has a negative correlation with the third turn-on duration of the switching device 5, which means that when the obtained resonance amplitude is small, the third turn-on duration of the switching device 5 needs to be increased to ensure sufficient energy transfer; conversely, if the resonance amplitude is large, the third turn-on duration should be reduced to avoid violent fluctuations in the magnetic field and potential abnormal noise problems caused by excessive current changes. This negative correlation can ensure that regardless of how the cookware material changes, the electromagnetic heating device 100 can adjust the third turn-on duration of the switching device 5 to smoothly transition from the startup stage to the stable operating state, and during the entire startup process, the switching device 5 can be turned on or off when approaching the voltage zero-crossing point, thereby effectively reducing the noise level and improving the heating efficiency at the same time.

[0053] Please refer to Figure 9 , in one embodiment, step S520A specifically includes: S521A. When it is determined that the resonance amplitude of the resonant circuit is not greater than the first preset resonance amplitude, increase the third turn-on duration of the switching device until, at the zero-crossing moment of the target power supply half-wave duration, the turn-on voltage of the switching device is reduced to zero; S522A. When it is determined that the resonance amplitude of the resonant circuit is greater than the first preset resonance amplitude, decrease the third turn-on duration of the switching device until, at the zero-crossing moment of the target power supply half-wave duration, the turn-on voltage of the switching device is reduced to zero.

[0054] It should be noted that the first preset resonance amplitude refers to the ideal resonance amplitude corresponding to the normal heating state of most common cookware. This amplitude represents that the equivalent impedance of the cookware is within a relatively ideal range, neither too high nor too low, which can ensure the stable operation of the electromagnetic heating device 100. Under this resonance amplitude condition, the magnetic permeability and conductivity of the cookware are moderate, resulting in a relatively high energy transfer efficiency. Without additional adjustment of the third turn-on duration of the switching device 5, the power output requirements and abnormal noise control requirements can be simultaneously met. In other words, when operating within this amplitude range, the electromagnetic heating device 100 can not only achieve efficient energy injection to maintain good heating performance, but also avoid significant electromagnetic noise or mechanical vibration caused by sudden changes in current, which would otherwise lead to violent fluctuations in the magnetic field. Therefore, the first preset resonance amplitude can be regarded as a reference threshold for the electromagnetic heating device 100 to determine whether to adjust the switching device 5. Only when the obtained resonance amplitude deviates from this ideal range will the adjustment of the third turn-on duration of the switching device 5 be triggered to further optimize the operating state and user experience of the electromagnetic heating device 100.

[0055] In this embodiment, step S520A is further refined into two judgment branches, which are used to adjust the third on-time of the switch device 5 according to the resonance amplitude of the resonance circuit to achieve more accurate abnormal sound control and heating efficiency optimization. Specifically, in step S521A, when the electromagnetic heating device 100 determines that the resonance amplitude of the resonance circuit is not greater than the first preset resonance amplitude, it indicates that the equivalent impedance of the pot is large (such as a pot made of non-magnetic or thin-walled materials). At this time, the third on-time of the switch device 5 can be increased to increase energy injection and ensure that the on-voltage of the switch device 5 can be reduced to zero at the zero-crossing moment of the target power half-wave duration; and in step S522A, if it is determined that the resonance amplitude is greater than the first preset resonance amplitude, it means that the equivalent impedance of the pot is small (such as a pot made of high magnetic permeability or thick-walled materials). At this time, the third on-time can be reduced to avoid violent fluctuations in the magnetic field caused by excessive current change rate, thereby reducing the risk of abnormal sound, and also ensuring that the voltage zeroing operation is completed at the zero-crossing moment. Through threshold judgment, the electromagnetic heating device 100 can automatically adjust the third opening time of the switch device 5 under different cookware material conditions, so that the switch device 5 always works close to the actual zero crossing point, effectively suppressing the noise during the startup process of the electromagnetic heating device 100, while improving the heating efficiency and stability.

[0056] See also Figure 10 In one embodiment, the step of adjusting the opening interval of the switch device according to the material of the cookware specifically includes: S510B, when it is determined that the resonance amplitude of the resonance circuit reaches a second preset resonance amplitude, controlling the switch device to turn on to adjust the turn-on interval of the switch device; The second preset resonance amplitude is smaller than the first preset resonance amplitude.

[0057] It should be noted that the second preset resonance amplitude is the minimum resonance amplitude threshold value set by the electromagnetic heating device 100, and its value is less than the first preset resonance amplitude. The second preset resonance amplitude is intended to identify the lowest energy transfer efficiency state that the electromagnetic heating device 100 may encounter during the startup process, that is, when the equivalent impedance of the cookware reaches a relatively high level or the material has poor magnetic conductivity. Specifically, the second preset resonance amplitude can reflect the standard of the electromagnetic heating device 100 operating under a more extreme but still acceptable working condition. When it is determined that the resonance amplitude is close to this threshold, it indicates that the current cookware material has a weak response to the magnetic field and a low energy transmission efficiency. It is necessary to optimize the energy injection method by adjusting the opening interval of the switching device 5 to ensure that the electromagnetic heating device 100 can still maintain a stable heating effect and a low noise level under low-efficiency transmission conditions.

[0058] In this embodiment, the specific steps of adjusting the on-time interval of the switching device 5 according to the cookware material are further refined to be adjusted based on the resonance amplitude of the resonant circuit. Specifically, in step S510B, when it is determined that the resonance amplitude of the resonant circuit reaches the second preset resonance amplitude, the electromagnetic heating device 100 controls the switching device 5 to turn on to adjust the on-time interval of the switching device 5, so as to optimize the way and frequency of energy input, and ensure that an ideal heating effect can be maintained even under low-efficiency transmission conditions and unnecessary noise can be reduced. For example, when it is determined that the resonance amplitude is close to the second preset resonance amplitude, it indicates that the current cookware may have a high resistivity or non-ideal magnetic conductivity. At this time, increasing the on-time interval of the switching device 5 helps to avoid violent fluctuations in the magnetic field caused by too fast energy injection, thereby reducing the risk of abnormal noise. Through the method of this embodiment, not only can the ability of the electromagnetic heating device 100 to cope with cookware of different materials be improved, but also the noise and vibration problems during the startup process can be minimized while ensuring efficient energy transmission, further enhancing the user experience and the overall reliability of the device.

[0059] Please refer to Figure 11 , in one embodiment, the abnormal noise control method of the electromagnetic heating device 100 further includes: S600. Obtain the turn-on voltage of the switching device; S700. When it is determined that the zero-crossing moment of the first turn-on duration of the switching device reaches the target half-wave duration and the turn-on voltage of the switching device reaches the preset turn-on voltage, stop extending the first turn-on duration in each on / off cycle of the switching device, and control the switching device to turn on / off according to the target on / off timing sequence.

[0060] In this embodiment, the abnormal noise control method of the electromagnetic heating device 100 further includes steps S600 and S700 to maximize the suppression of abnormal noise generation while optimizing the operation of the switching device 5. First, in step S600, the electromagnetic heating device 100 obtains the turn-on voltage of the switching device 5, which is the key to determining when to stop extending the first turn-on duration of the switching device 5. Then, in step S700, when the electromagnetic heating device 100 confirms that the first turn-on duration of the switching device 5 has reached the zero-crossing moment of the target half-wave duration and the turn-on voltage of the switching device 5 reaches the preset turn-on voltage (i.e., the set minimum turn-on voltage), the electromagnetic heating device 100 will stop continuing to extend the first turn-on duration in each on / off cycle and precisely control the turn-on / off of the switching device 5 according to the target on / off timing. This means that the electromagnetic heating device 100 will smoothly transition from the startup stage to the normal heating stage and start to efficiently heat the cookware. Among them, the preset turn-on voltage is the lowest voltage threshold at which the switching device 5 can work safely and reliably, ensuring stable energy transmission even when approaching the voltage zero-crossing point and with a low input voltage, and avoiding unstable switching or additional electromagnetic noise caused by insufficient voltage. Through this control method, the electromagnetic heating device 100 can not only achieve fine control of the startup process but also reduce the risk of abnormal noise and improve the overall operation efficiency and user experience of the device.

[0061] The present invention also provides an abnormal noise control device 1 for the electromagnetic heating device 100. Please refer to Figure 12 , the abnormal noise control device 1 for the electromagnetic heating device 100 includes a memory 11 and a processor 12. The memory 11 is used to store the abnormal noise control program for the electromagnetic heating device 100, and the processor 12 is used to execute the abnormal noise control program for the electromagnetic heating device 100 to implement the abnormal noise control method for the electromagnetic heating device 100 as described above. The specific structure of the abnormal noise control method for the electromagnetic heating device 100 refers to the above embodiment. Since the abnormal noise control device 1 for the electromagnetic heating device 100 adopts all the technical solutions of the above all embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated here one by one.

[0062] The present invention also provides an electromagnetic heating device 100. Please refer to Figure 13 , the electromagnetic heating device 100 includes a rectifier and filter circuit 2, a panel 3, a wire coil 4, and an abnormal noise control device 1 for the electromagnetic heating device 100. The specific structure of the abnormal noise control device 1 for the electromagnetic heating device 100 refers to the above embodiment. Since the electromagnetic heating device 100 adopts all the technical solutions of the above all embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be elaborated here one by one.

[0063] Among them, the electromagnetic heating device 100 can be an induction cooker, a steaming device, a stir-frying robot, etc., and is not specifically limited. The electromagnetic heating device 100 may include, but is not limited to, a rectifier filter circuit 2, a panel 3, a switching device 5, a coil disk 4, and a abnormal sound control device 1. The rectifier filter circuit 2 is used to convert the externally input mains power into stable direct current; the panel 3 is not only used to place cookware, but also can realize interactive operations with users; the switching device 5 is used to convert the direct current output by the rectifier filter circuit 2 into high-frequency alternating current; the coil disk 4 is used to generate a high-frequency alternating magnetic field when high-frequency alternating current passes through. In practical applications, when the electromagnetic heating device 100 works, the mains power (such as 220V alternating current) first passes through the rectifier filter circuit 2 and is converted into a direct current voltage. Since the rectified voltage is processed by capacitor filtering and the like, a direct current voltage slightly higher than the peak value of the original alternating current voltage can be obtained. For 220V mains power, this value is approximately 310V, which is the so-called DC bus voltage. Then, the switching device 5 converts this DC bus voltage into a high-frequency alternating voltage. When the high-frequency alternating current passes through the coil disk 4, a high-frequency alternating magnetic field is generated. When a cookware made of ferromagnetic material is placed on the panel 3, under the action of the high-frequency alternating magnetic field, the bottom of the pot will cut the magnetic force lines to generate an induced current. According to the eddy current effect, these induced currents will form heat energy at the bottom of the pot, thereby realizing the heating of food.

[0064] It should be noted that the abnormal sound control device 1 can obtain the target power input frequency, the target power input voltage, and the target on / off timing of the switching device 5, and determine the target power half-wave duration and the zero-crossing moment of the voltage of the target power half-wave duration based on the obtained target power input frequency and target power input voltage. When it is detected that the cookware has been placed on the panel 3 of the electromagnetic heating device 100 and starts to heat, the abnormal sound control device 1 controls the switching device 5 to work and gradually extends the on-time in each on / off cycle of the switching device 5. This process continues until at the zero-crossing moment of the target power half-wave duration, the on and off of the switching device 5 can be accurately controlled according to the preset target on / off timing. Specifically, the switching device 5 can be turned on and then turned off with a preset first on-time (such as 2 μs) in the first on / off cycle. When entering the second on / off cycle, the on-time of the current cycle can be appropriately extended based on the first on / off cycle, for example, extended from 2 μs to 3 μs, or even further extended to 4 μs, etc., and the specific value is not limited. By increasing the on-time cycle by cycle, finally, the switching device 5 can perform the on or off operation according to the target on / off timing at the zero-crossing moment of the target power half-wave duration. If the switching device 5 is turned on at this zero-crossing moment, it will be turned off after operating according to the set on-time in the target on / off timing; conversely, if the switching device 5 is turned off at this zero-crossing moment, it will be turned on after operating according to the set off-time in the target on / off timing. Regardless of which on / off cycle the switching device 5 works in, when the switching device 5 is turned on, the current in the wire coil 4 starts to increase from zero. Due to the inductance of the wire coil 4, the current cannot change instantaneously but rises at a certain slope. When the switching device 5 is turned off, the current in the wire coil 4 continues to flow through the freewheeling diode circuit and gradually decreases to zero. Through this control method, the current in the wire coil 4 can increase or decrease smoothly with the operation of the switching device 5, specifically, it increases smoothly when the switching device 5 is turned on and decreases smoothly when the switching device 5 is turned off, thereby avoiding the abnormal sound generated by the sharp change of the current in the wire coil 4 during the startup process of the electromagnetic heating device 100 and improving the overall performance and user experience of the electromagnetic heating device 100.

[0065] The above is only an exemplary embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structural transformation made under the technical concept of the present invention by using the content of the specification and drawings of the present invention, or directly / indirectly applied to other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A method for controlling abnormal noise of an electromagnetic heating device, characterized in that, The electromagnetic heating device includes a switching device. The abnormal sound control method of the electromagnetic heating device includes: Obtaining a target power supply input frequency, a target power supply input voltage, and a target on / off timing of the switching device; Determining the zero-crossing moment of the half-wave duration of the target power supply according to the obtained target power supply input frequency and target power supply input voltage; When a cookware is detected and heating is started, controlling the switching device to work and gradually extending the first on-time duration in each on / off cycle of the switching device until, at the zero-crossing moment of the half-wave duration of the target power supply, controlling the switching device to turn on / off according to the target on / off timing.

2. The abnormal sound control method of the electromagnetic heating device according to claim 1, characterized in that, The abnormal sound control method of the electromagnetic heating device further includes: When heating stops, extending the second on-time duration of the switching device according to the half-wave duration of the target power supply until, at the zero-crossing moment of the half-wave duration of the target power supply, controlling the switching device to turn off.

3. The abnormal noise control method of the electromagnetic heating device according to claim 1, characterized in that, The step of determining the zero-crossing moment of the half-wave duration of the target power supply according to the obtained target power supply input frequency and target power supply input voltage specifically includes: Obtaining a target power supply input frequency, a target power supply input voltage, a preset frequency factor, and a preset voltage factor; Determining a target frequency influence coefficient according to the target power supply input frequency and the preset frequency factor, and determining a target voltage influence coefficient according to the target power supply input voltage and the preset voltage factor; Determining the zero-crossing moment of the half-wave duration of the target power supply according to the target frequency influence coefficient and the target voltage influence coefficient.

4. The abnormal noise control method of the electromagnetic heating device according to claim 1, characterized in that, The step of obtaining a target power supply input frequency, a target power supply input voltage, and a target on / off timing of the switching device further includes: Obtaining a preset first on-time duration; The step of, when a cookware is detected and heating is started, controlling the switching device to work and gradually extending the first on-time duration in each on / off cycle of the switching device until, at the zero-crossing moment of the half-wave duration of the target power supply, controlling the switching device to turn on / off according to the target on / off timing specifically includes: When a cookware is detected and heating is started, controlling the switching device to turn on for the preset first on-time duration; After the switching device is turned on for the preset first on-time duration, gradually extending the first on-time duration in each on / off cycle of the switching device until, at the zero-crossing moment of the half-wave duration of the target power supply, controlling the switching device to turn on / off according to the target on / off timing.

5. The abnormal noise control method of the electromagnetic heating device according to claim 1, characterized in that, The electromagnetic heating device further includes a resonant circuit. The resonant circuit includes a resonant capacitor and a wire coil. The step of obtaining the preset first on-time duration specifically includes: Obtaining the capacitance value of the resonant capacitor, the inductance value of the wire coil, and the turn-on voltage of the switching device; Performing parameter debugging based on the capacitance value of the resonant capacitor, the inductance value of the wire coil, and the turn-on voltage of the switching device to determine the preset first on-time duration.

6. The abnormal sound control method of the electromagnetic heating device according to claim 1, characterized in that The abnormal sound control method of the electromagnetic heating device further includes: Adjusting the third on-time duration, turn-on interval, or period of the switching device according to the material of the cookware.

7. The abnormal sound control method of the electromagnetic heating device according to claim 6, characterized in that, The electromagnetic heating device further includes a resonant circuit; the step of adjusting the third on-time duration of the switching device according to the material of the cookware specifically includes: Obtaining the resonant amplitude of the resonant circuit; Adjust the third turn-on duration of the switching device according to the resonance amplitude of the resonant circuit until, at the zero-crossing moment of the target power supply half-wave duration, the turn-on voltage of the switching device is controlled to drop to zero.

8. The abnormal noise control method of the electromagnetic heating device according to claim 7, characterized in that, The resonance amplitude of the resonant circuit has a negative correlation with the third turn-on duration of the switching device.

9. The abnormal sound control method of the electromagnetic heating device according to claim 8, characterized in that, The step of adjusting the third turn-on duration of the switching device according to the resonance amplitude of the resonant circuit until, at the zero-crossing moment of the target power supply half-wave duration, the turn-on voltage of the switching device is controlled to drop to zero specifically includes: When it is determined that the resonance amplitude of the resonant circuit is not greater than the first preset resonance amplitude, increase the third turn-on duration of the switching device until, at the zero-crossing moment of the target power supply half-wave duration, the turn-on voltage of the switching device is controlled to drop to zero; When it is determined that the resonance amplitude of the resonant circuit is greater than the first preset resonance amplitude, decrease the third turn-on duration of the switching device until, at the zero-crossing moment of the target power supply half-wave duration, the turn-on voltage of the switching device is controlled to drop to zero.

10. The abnormal sound control method of the electromagnetic heating device according to claim 9, characterized in that, The step of adjusting the turn-on interval of the switching device according to the material of the cookware specifically includes: When it is determined that the resonance amplitude of the resonant circuit reaches the second preset resonance amplitude, control the switching device to turn on to adjust the turn-on interval of the switching device; Wherein, the second preset resonance amplitude is less than the first preset resonance amplitude.

11. The abnormal noise control method of the electromagnetic heating device according to claim 1, characterized in that The abnormal sound control method of the electromagnetic heating device further includes: Obtain the turn-on voltage of the switching device; When it is determined that the first turn-on duration of the switching device reaches the zero-crossing moment of the target half-wave duration and the turn-on voltage of the switching device reaches the preset turn-on voltage, stop extending the first turn-on duration in each on / off cycle of the switching device, and control the switching device to turn on / off according to the target on / off timing.

12. An abnormal noise control device, characterized in that, Includes: A memory; A processor, an abnormal sound control program of the electromagnetic heating device stored on the memory and executed by the processor, the abnormal sound control program, when executed by the processor, implements the abnormal sound control method of the electromagnetic heating device according to any one of claims 1 to 11.

13. An electromagnetic heating device, characterized in that, Includes the abnormal sound control device according to claim 12.

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