Noise control methods and devices for electromagnetic heating equipment and electromagnetic heating equipment

Abstract

This invention discloses a method, device, and electromagnetic heating device for controlling abnormal noise in an electromagnetic heating equipment, relating to the technical field of electromagnetic heating equipment. The electromagnetic heating equipment includes a switching device, and the method for controlling abnormal noise includes: acquiring the target power input frequency, target power input voltage, and target on / off timing of the switching device; determining the zero-crossing point of the target power half-wave duration based on the acquired target power input frequency and voltage; when a pot is detected and heating is initiated, controlling the switching device to operate and gradually extending the first on-time in each on / off cycle of the switching device until the zero-crossing point of the target power half-wave duration, then controlling the switching device to turn on / off according to the target on / off timing. The technical solution provided by this invention can solve the problem in the prior art where the pot produces significant abnormal noise due to directly driving the switching device under high voltage conditions.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic heating equipment technology, and in particular to a method, device, and electromagnetic heating equipment for controlling abnormal noise. Background Technology

[0002] During the operation of electromagnetic heating equipment, the 220V AC mains power is rectified and filtered to convert to a 310V DC bus voltage. Some electromagnetic heating devices on the market do not use soft-start technology when detecting and starting the cookware, but instead drive the IGBT directly under high voltage conditions, which can cause noticeable abnormal noise from the cookware. Summary of the Invention

[0003] The main objective of this invention is to propose a method, device, and electromagnetic heating device for controlling abnormal noise in electromagnetic heating equipment, aiming to solve the problem in the prior art where cookware produces obvious abnormal noise due to directly driving switching devices under high voltage conditions.

[0004] To achieve the above objectives, the present invention proposes a method for controlling abnormal noise in an electromagnetic heating device, wherein the electromagnetic heating device includes a switching device, and the method for controlling abnormal noise in the electromagnetic heating device includes:

[0005] Obtain the target power input frequency, target power input voltage, and target on / off timing of the switching devices;

[0006] Based on the obtained target power input frequency and target power input voltage, determine the zero-crossing time of the target power half-wave duration;

[0007] When the cookware is detected and heating is started, the switching device is controlled to work and the first on-time of each on / off cycle of the switching device is gradually extended until the zero-crossing point of the target power supply half-wave duration is reached, at which point the switching device is controlled to turn on / off according to the target on / off sequence.

[0008] In one embodiment, the noise control method for the electromagnetic heating device further includes:

[0009] When heating stops, the second turn-on duration of the switching device is extended according to the half-wave duration of the target power supply until the switching device is turned off at the zero-crossing point of the half-wave duration of the target power supply.

[0010] In one embodiment, the step of determining the zero-crossing time of the target power supply half-wave duration based on the acquired target power supply input frequency and target power supply input voltage specifically includes:

[0011] Acquire the target power input frequency, target power input voltage, preset frequency factor, and preset voltage factor;

[0012] The target frequency influence coefficient is determined based on the target power input frequency and the preset frequency factor, and the target voltage influence coefficient is determined based on the target power input voltage and the preset voltage factor.

[0013] The zero-crossing time of the target power supply half-wave duration is determined based on the target frequency influence coefficient and the target voltage influence coefficient.

[0014] In one embodiment, the step of obtaining the target power input frequency, the target power input voltage, and the target on / off timing of the switching devices further includes:

[0015] Get the preset initial activation duration;

[0016] The step of controlling the switching device to operate and gradually extending the first on-time of the switching device in each on / off cycle when the cookware is detected and heating is started, until the zero-crossing point of the target power supply half-wave duration, and controlling the switching device to turn on / off according to the target on / off sequence specifically includes:

[0017] When the cookware is detected and heating is started, the control switch is turned on for a preset initial on-time duration;

[0018] After the switching device is turned on for a preset initial turn-on duration, the first turn-on duration in each turn-on / turn-off cycle of the switching device is gradually extended until the zero-crossing point of the target power supply half-wave duration is reached, at which point the switching device is turned on / off according to the target turn-on / turn-off sequence.

[0019] In one embodiment, the electromagnetic heating device further includes a resonant circuit, which includes a resonant capacitor and a coil. The step of obtaining the preset initial start-up time specifically includes:

[0020] Obtain the capacitance value of the resonant capacitor, the inductance value of the coil, and the turn-on voltage of the switching device;

[0021] Based on the capacitance value of the resonant capacitor, the inductance value of the coil, and the turn-on voltage of the switching device, the parameters are adjusted to determine the preset initial turn-on duration.

[0022] In one embodiment, the noise control method for the electromagnetic heating device further includes:

[0023] Adjust the third on-time, on-interval, or cycle of the switching device according to the material of the cookware.

[0024] In one embodiment, the electromagnetic heating device further includes a resonant circuit; the step of adjusting the third on-time of the switching device according to the material of the cookware specifically includes:

[0025] Obtain the resonant amplitude of the resonant circuit;

[0026] Based on the resonance amplitude of the resonant circuit, the third turn-on duration of the switching device is adjusted until the turn-on voltage of the switching device is reduced to zero at the zero-crossing point of the target power supply half-wave duration.

[0027] In one embodiment, the resonant amplitude of the resonant circuit is negatively correlated with the third turn-on duration of the switching device.

[0028] In one embodiment, the step of adjusting 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 drops to zero at the zero-crossing point of the target power supply half-wave duration specifically includes:

[0029] When it is determined that the resonance amplitude of the resonant circuit is not greater than the first preset resonance amplitude, the third turn-on duration of the switching device is increased until the turn-on voltage of the switching device is controlled to drop to zero at the zero-crossing point of the half-wave duration of the target power supply.

[0030] When it is determined that the resonance amplitude of the resonant circuit is greater than the first preset resonance amplitude, the third turn-on duration of the switching device is reduced until the turn-on voltage of the switching device is reduced to zero at the zero-crossing point of the half-wave duration of the target power supply.

[0031] In one embodiment, the step of adjusting the opening interval of the switching device according to the material of the cookware specifically includes:

[0032] When the resonant amplitude of the resonant circuit is determined to reach the second preset resonant amplitude, the switching device is turned on to adjust the opening interval of the switching device.

[0033] Wherein, the second preset resonance amplitude is less than the first preset resonance amplitude.

[0034] In one embodiment, the noise control method for the electromagnetic heating device further includes:

[0035] Obtain the turn-on voltage of the switching device;

[0036] When the first turn-on duration of the switching device reaches the zero-crossing point of the target half-wave duration, and the turn-on voltage of the switching device reaches the preset turn-on voltage, the extension of the first turn-on duration in each turn-on / turn-off cycle of the switching device is stopped, and the switching device is controlled to turn on / off according to the target turn-on / turn-off sequence.

[0037] The present invention also proposes an abnormal noise control device, comprising:

[0038] Memory;

[0039] The processor stores a noise control program for the electromagnetic heating device in the memory and executes it. When executed by the processor, the noise control program implements the noise control method for the electromagnetic heating device as described above.

[0040] The present invention also proposes an electromagnetic heating device, including the noise control device described above.

[0041] The technical solution of this invention obtains the target power input frequency and voltage, and determines the zero-crossing point of the target power half-wave duration accordingly. When the cookware is detected and heating is started, the switching device is controlled to operate and its on-time in each on / off cycle is gradually extended, thereby achieving a smooth increase in power, rather than directly applying high power at the moment of startup. This effectively avoids voltage peaks during the startup phase of the electromagnetic heating equipment, allowing the operating current of the equipment to increase gradually and reducing cookware vibration and abnormal noise caused by sudden changes in the magnetic field. After reaching the zero-crossing point of the target power half-wave duration, the switching device is controlled to turn on / off according to the preset target on / off sequence. This method ensures that the switching device operates with a short on-time in the initial stage of equipment startup, and then gradually extends to the on-time required for normal operation, thereby avoiding electromagnetic shocks and mechanical vibrations caused by sudden current changes at startup, and effectively suppressing abnormal noise generated by electromagnetic force pulsation in the cookware during startup. This invention can solve the problem of obvious abnormal noise in the cookware caused by directly driving the switching device under high voltage conditions in the prior art, and significantly improves the operational stability and reliability of electromagnetic heating equipment during startup. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0043] Figure 1 A flowchart of the first embodiment of the noise control method for an electromagnetic heating device provided by the present invention;

[0044] Figure 2 A comparison graph showing the changes in the input voltage of the target power supply and the operating voltage of the coil of the electromagnetic heating device provided by the present invention over time;

[0045] Figure 3 A flowchart of the second embodiment of the noise control method for an electromagnetic heating device provided by the present invention;

[0046] Figure 4A flowchart of the third embodiment of the noise control method for an electromagnetic heating device provided by the present invention;

[0047] Figure 5 A flowchart of the fourth embodiment of the noise control method for electromagnetic heating equipment provided by the present invention;

[0048] Figure 6 A flowchart of the fifth embodiment of the noise control method for electromagnetic heating equipment provided by the present invention;

[0049] Figure 7 A flowchart of the sixth embodiment of the noise control method for electromagnetic heating equipment provided by the present invention;

[0050] Figure 8 A flowchart of the seventh embodiment of the noise control method for electromagnetic heating equipment provided by the present invention;

[0051] Figure 9 A flowchart of the eighth embodiment of the noise control method for electromagnetic heating equipment provided by the present invention;

[0052] Figure 10 A flowchart of the ninth embodiment of the noise control method for electromagnetic heating equipment provided by the present invention;

[0053] Figure 11 A flowchart of the tenth embodiment of the noise control method for an electromagnetic heating device provided by the present invention;

[0054] Figure 12 A schematic diagram of the circuit functional modules of an embodiment of the noise control device provided by the present invention;

[0055] Figure 13 This is a schematic diagram of the circuit functional modules of an embodiment of the electromagnetic heating device provided by the present invention.

[0056] Explanation of icon numbers:

[0057] 100. Electromagnetic heating equipment; 1. Noise control device; 11. Memory; 12. Processor; 2. Rectifier and filter circuit; 3. Panel; 4. Coil; 5. Switching device.

[0058] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0059] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0060] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0061] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0062] During the operation of electromagnetic heating equipment, the 220V AC mains power is rectified and filtered to convert to a 310V DC bus voltage. Some electromagnetic heating devices on the market do not use soft-start technology when detecting and starting the cookware, but instead drive the IGBT directly under high voltage conditions, which can cause noticeable noise from the cookware.

[0063] To address the above problems, this invention proposes a method for controlling abnormal noise in an electromagnetic heating device 100.

[0064] Please see Figure 1 , Figure 2 and Figure 13 In one embodiment of the present invention, the electromagnetic heating device 100 includes a switching device 5, and the noise control method of the electromagnetic heating device 100 includes:

[0065] S100A: Obtain the target power input frequency, target power input voltage, and target on / off timing of the switching devices;

[0066] S200. Determine the zero-crossing time of the target power supply half-wave duration based on the obtained target power supply input frequency and target power supply input voltage.

[0067] S300: When the cookware is detected and heating is started, the switching device is controlled to work and the on-time of the switching device 5 in each on / off cycle is gradually extended until the zero-crossing point of the target power supply half-wave duration is reached, and the switching device is controlled to turn on / off according to the target on / off sequence.

[0068] In this embodiment, the electromagnetic heating device 100 can be an induction cooker, a steaming / cooking device, or a cooking robot, etc., and is not specifically limited. The electromagnetic heating device 100 mainly includes a switching device 5, but this does not mean that its structure consists only of the switching device 5. It can also further integrate related components such as a rectifier filter circuit 2, a panel 3, and a coil 4 according to actual needs. For ease of explanation, the following uses the electromagnetic heating device 100 including a rectifier filter circuit 2, a panel 3, a switching device 5, and a coil 4 as an example to describe its hardware structure and working principle in detail: The rectifier filter circuit 2 is used to convert the externally input mains power into stable DC power; the panel 3 is not only used to place cookware but also to enable interactive operation with the user; the switching device 5 is used to convert the DC power output by the rectifier filter circuit 2 into high-frequency AC power; the coil 4 is used to generate a high-frequency alternating magnetic field when the high-frequency AC power passes through. In practical applications, when the electromagnetic heating device 100 is working, the mains power (e.g., 220V AC) is first converted into DC voltage by the rectifier filter circuit 2. Because the rectified voltage undergoes capacitor filtering and other processing, a DC voltage slightly higher than the original AC voltage peak value is obtained. For 220V AC mains power, this value is approximately 310V, which is the so-called DC bus voltage. This DC bus voltage is then converted into a high-frequency AC voltage by switching device 5. This high-frequency AC current generates a high-frequency alternating magnetic field when passing through coil 4. When a pot containing ferromagnetic material is placed on panel 3, the bottom of the pot cuts magnetic lines of force under the influence of the high-frequency alternating magnetic field, generating an induced current. According to the eddy current effect, these induced currents generate heat energy at the bottom of the pot, thus heating the food.

[0069] However, some electromagnetic heating devices 100 currently on the market do not employ soft-start technology when detecting and starting a pot. Soft-start is a technology that achieves smooth device startup by gradually increasing the input voltage. It is primarily used to avoid damage to the device's circuit components due to a sudden surge in current during startup, and also helps reduce electromagnetic noise and mechanical vibration. If the electromagnetic heating device 100 does not use soft-start technology and instead directly drives the switching device 5 under high voltage conditions when detecting and starting a pot, the current in the coil 4 will rise rapidly. This rapidly changing current will cause rapid fluctuations in the magnetic field strength, resulting in drastic changes in the eddy currents generated at the bottom of the pot, which may cause mechanical vibration of the pot and produce noticeable abnormal noise. This is because metal pots undergo slight physical deformation when subjected to a high-intensity and rapidly changing high-frequency alternating magnetic field. The accumulated vibration effects caused by these physical deformations create a sound that is audible to the human ear.

[0070] To address the aforementioned challenges, this invention proposes a noise control method for an electromagnetic heating device 100, aiming to solve the problem of significant noise generated in cookware due to directly driving the switching device 5 under high voltage conditions in the prior art. In this embodiment, the noise control method for the electromagnetic heating device 100 achieves control of the switching device 5 through the following three steps, thereby reducing the noise generated by the electromagnetic heating device 100 during startup and improving the stability of the electromagnetic heating device 100. First, in step S100A, the electromagnetic heating device 100 acquires the target power input frequency, the target power input voltage, and the target on / off timing of the switching device 5 as the basis for subsequent control. The target power source can be mains power, a power bank, or other power sources. In this embodiment, the target power source mainly refers to mains power. Correspondingly, the target power input frequency is the standard frequency of the power system connected to the electromagnetic heating device 100 during use. Different countries or regions use different standard frequencies; most countries use 50 Hz or 60 Hz as the standard frequency of their power systems. The target power input voltage refers to the AC voltage value connected to the electromagnetic heating device 100, which also varies by country and region. For example, in some countries, the standard voltage for household electricity is 120V (single-phase) or 240V (multi-phase), while in other countries, the standard voltage for household electricity is 230V.

[0071] 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 point of that half-wave duration are determined. Due to differences in mains input voltage and frequency across different countries, the actual input voltage range is generally 100V~240V, and the frequency range is typically 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 software zero-crossing point appears. Here, "software zero-crossing point" refers to the moment when the current or voltage of the coil 4, as identified by the internal software algorithm of the electromagnetic heating device 100, crosses zero, indicating a transition from the positive half-cycle to the negative half-cycle or vice versa. For alternating current, the zero-crossing point is the moment when the voltage or current waveform of the coil 4 crosses zero within one cycle. In a complete sine wave cycle, a zero-crossing phenomenon occurs once every half-cycle. Specifically, for AC power with an input frequency of 50Hz, the complete cycle is 20ms, so the zero-crossing occurs approximately every 10ms; while for AC power with a frequency of 60Hz, the complete cycle is 16.67ms, and the zero-crossing occurs approximately every 8.33ms. Therefore, the software zero-crossing point changes with the mains input voltage and / or frequency. Thus, the noise control method in this embodiment obtains the accurate target power input frequency and voltage, and calculates the corresponding target half-wave duration and its zero-crossing time accordingly, ensuring that the switching device 5 can be turned on or off at the true zero-crossing point, thereby effectively reducing noise caused by switching actions and improving the operational stability of the electromagnetic heating equipment 100.

[0072] Finally, in step S300, when the electromagnetic heating device 100 detects that the pot has been placed on the panel 3 of the electromagnetic heating device 100 and has started heating, the electromagnetic heating device 100 controls the switching device 5 to operate and gradually extends the on-time of the switching device 5 in each on / off cycle. This process continues until, at the zero-crossing point of the target power supply half-wave duration, the switching device 5 can be precisely controlled to turn on and off according to the preset target on / off sequence. Specifically, the switching device 5 can turn on and off in the first on / off cycle after a preset initial on-time (e.g., 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, the switching device 5 can finally perform the on or off operation according to the target on / off sequence at the zero-crossing point of the target power supply half-wave duration. If the switching device 5 is turned on at the zero-crossing point, it will run for the set on-time in the target on / off sequence and then turn off; conversely, if the switching device 5 is turned off at the zero-crossing point, it will run for the set off-time in the target on / off sequence and then turn on.

[0073] But from Figure 2 It can be observed that regardless of the on / off cycle of the switching device 5, when the switching device 5 is turned on, the current in the coil 4 increases from zero. Due to the inductance of the 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 coil 4 continues through the freewheeling diode circuit, and the current gradually decreases to zero. Through this control method, the current in the coil 4 can smoothly increase or decrease 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. This avoids abnormal noise caused by the rapid change in the current in the coil 4 during the startup of the electromagnetic heating device 100, thus improving the overall performance and user experience of the electromagnetic heating device 100.

[0074] The technical solution of this invention obtains the target power input frequency and target power input voltage, and determines the zero-crossing time of the target power half-wave duration accordingly. When the cookware is detected and heating is started, the switching device 5 is controlled to operate and its on-time in each on / off cycle is gradually extended, thereby achieving a smooth increase in power, rather than directly applying high power at the moment of startup. This effectively avoids voltage peaks during the startup phase of the electromagnetic heating device 100, allowing the operating current of the device to increase gradually and reducing cookware vibration and abnormal noise caused by sudden changes in the magnetic field. After reaching the zero-crossing time of the target power half-wave duration, the switching device 5 is controlled to turn on / off according to the preset target on / off sequence. This method ensures that the switching device 5 operates with a short on-time in the initial stage of device startup, and then gradually extends to the on-time required for normal operation, thereby avoiding electromagnetic shocks and mechanical vibrations caused by sudden changes in current at startup, and effectively suppressing abnormal noises caused by electromagnetic force pulsation in the cookware during startup. This invention can solve the problem of obvious abnormal noise in the cookware caused by directly driving the switching device 5 under high voltage conditions in the prior art, and significantly improve the operational stability and reliability of the electromagnetic heating device 100 during the startup process.

[0075] In existing technology, when the electromagnetic heating device 100 stops heating, if the switching device 5 does not turn off at the zero-crossing point of the current, the sudden interruption of the current will cause a sharp change in the magnetic field, which in turn will cause the cookware to vibrate mechanically and generate noise. To solve this problem, please refer to [link to relevant documentation]. Figure 3 In one embodiment, the noise control method of the electromagnetic heating device 100 further includes:

[0076] S400: When heating stops, extend the second turn-on duration of the switching device according to the half-wave duration of the target power supply until the switching device is turned off at the zero-crossing point of the half-wave duration of the target power supply.

[0077] In this embodiment, in step S400, when the electromagnetic heating device 100 stops heating the pot on the panel 3, it does not immediately turn off the switching device 5. Instead, based on the previously determined target power half-wave duration, the second on-time of the switching device 5 is extended until the voltage or current crosses zero at the target power half-wave duration, at which point the switching device 5 is delayed to turn off. By delaying the turn-off, the timing of the switching device 4 is actually adjusted to avoid sudden disconnection at non-zero-crossing moments. Directly turning off the switching device 5 at non-zero-crossing moments would cause a rapid interruption of the current in the coil 4, resulting in a sharp change in the magnetic field strength. This rapid change could not only cause mechanical vibration of the pot but also generate significant noise. Conversely, by extending the second on-time, the turn-off action of the switching device 5 can occur precisely at the zero-crossing moment when the voltage or current is close to zero. This ensures that the current in the coil 4 can naturally decay to near zero before being cut off, avoiding the negative impact of sudden current changes.

[0078] To facilitate understanding, an example is given below: Assume the target power supply half-wave duration is 10ms, i.e., the complete cycle is 20ms. Under normal circumstances, switching device 5 may turn off at 18ms, 19ms, or even other non-zero-crossing moments, instead of turning off at the zero-crossing point of 20ms. This premature turn-off causes a sudden change in the current in coil 4 due to the rapid turn-off of switching device 5, resulting in violent magnetic field fluctuations and abnormal noise. To avoid this problem, this embodiment achieves the turn-off of switching device 5 by extending the second turn-on duration of switching device 5 in the current on / off cycle. For example, if the originally set second turn-on duration is 2μs, it can be extended to 3μs as needed; if this duration is still insufficient for switching device 5 to complete the turn-off at the zero-crossing moment of the target power supply half-wave duration, i.e., switching device 5 fails to turn off at the zero-crossing point of 20ms, it can be further extended to 4μs, and so on. In this way, it can be ensured that the current in coil 4 has sufficient time to gradually decay to near zero near the next zero-crossing point, avoiding drastic changes in the magnetic field caused by sudden current interruption. This not only reduces mechanical vibration and noise in the cookware caused by sudden magnetic field changes, but also improves the stability and safety of the electromagnetic heating device 100, further optimizing the user experience. In other words, the noise control method provided in this embodiment can solve the noise problem that may be caused by improper timing of the switching device 5's turn-off during the heating process of the electromagnetic heating device 100, enhancing the operational reliability of the electromagnetic heating device 100.

[0079] Please see Figure 4 In one embodiment, step S200 specifically includes:

[0080] S210: Obtain the target power input frequency, target power input voltage, preset frequency factor, and preset voltage factor;

[0081] S220. Determine the target frequency influence coefficient based on the target power input frequency and the preset frequency factor, and determine the target voltage influence coefficient based on the target power input voltage and the preset voltage factor.

[0082] S230. Determine the zero-crossing time of the target power supply half-wave duration based on the target frequency influence coefficient and the target voltage influence coefficient.

[0083] Understandably, during the production 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 mains half-wave duration of the electromagnetic heating device 100. Specifically, by conducting experiments with different mains input frequencies from 40Hz to 60Hz, the first mains half-wave duration of the electromagnetic heating device 100 corresponding to each mains input frequency is obtained. Based on multiple sets of mains input frequencies and their corresponding first mains half-wave durations, the first correlation function is fitted. The first correlation function can be a linear or 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 mains half-wave duration of the electromagnetic heating device 100. That is, by adjusting the mains input voltage within the range of 100V to 270V, the second mains half-wave duration corresponding to each mains input voltage is obtained. Based on multiple sets of mains input voltages and their corresponding second mains half-wave durations, the second correlation function is fitted. The second correlation function can also be a linear or nonlinear relationship, from which a preset voltage factor can be extracted and stored in the electromagnetic heating device 100.

[0084] In this embodiment, step S200 is used to determine the zero-crossing time of the target power supply half-wave duration, and specifically includes the following three steps: First, in step S210, the electromagnetic heating device 100 acquires the target power supply input frequency, target power supply input voltage, preset frequency factor, and preset voltage factor, wherein 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 time of the target power supply half-wave duration. 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 power conditions, and their function is to compensate for the software judgment deviation caused by changes in the actual mains power 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 preset frequency factor, and its expression is: Target frequency influence coefficient = (Preset input frequency - Target power supply input frequency) × Preset frequency factor. If 50Hz is used as the preset input frequency, the formula is specifically: Target frequency influence coefficient = (50 - Target power supply input frequency) × Preset frequency factor. Simultaneously, the electromagnetic heating device 100 also uses the target power input voltage and preset voltage factor to determine the target voltage influence coefficient, which is expressed as: Target frequency influence coefficient = (Target input voltage - Preset input voltage) × First preset voltage factor + Second preset voltage factor. If 230V is used as the preset input voltage, the specific formula is: 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 time calculated by the electromagnetic heating device 100, thereby ensuring that the calculation result is as close as possible to the actual voltage or current zero-crossing point. Finally, in step S230, the target frequency influence coefficient and target voltage influence coefficient determined above are summed to obtain the zero-crossing time of the target power supply half-wave duration. In this way, the electromagnetic heating device 100 can calculate the zero-crossing time of the target power supply half-wave duration, enabling the switching device 5 to turn on or off at the most appropriate time (i.e., close to the actual zero-crossing point). This effectively reduces electromagnetic noise and mechanical vibration caused by non-zero-point operation, improving the stability of the electromagnetic heating device 100 and the user experience. In other words, the method provided in this embodiment not only solves the problem caused by the mismatch between the software zero-crossing point and the actual zero-crossing point in traditional methods, but also enhances the overall performance of the electromagnetic heating device 100.

[0085] Please see Figure 5 In one embodiment, step S100A further includes:

[0086] S100B, Obtain the preset initial activation duration;

[0087] In this embodiment, step S100A, in addition to acquiring the target power input frequency, target power input voltage, and target on / off timing of the switching device 5, also includes step S100B, which acquires the preset initial turn-on duration. This parameter serves as the initial turn-on duration for controlling the switching device 5 to turn on during the initial startup of the electromagnetic heating device 100. Optionally, the preset initial turn-on duration is not less than 2µs and not more than 5µs. By limiting the preset initial turn-on duration to this range, the rate of increase of the current in the coil 4 can be effectively limited during the initial startup of the electromagnetic heating device 100, avoiding insufficient power due to too short a turn-on time or current surge due to too long a turn-on time, thereby achieving a smooth soft start.

[0088] Step S300 specifically includes:

[0089] S310. When the pot is detected and heating is started, the control switch is turned on for a preset initial turn-on time.

[0090] S320. After the preset initial turn-on duration of the switching device is turned on, the first turn-on duration of each turn-on / turn-off cycle of the switching device is gradually extended until the zero-crossing point of the target power supply half-wave duration is reached, and the switching device is turned on / off according to the target turn-on / turn-off sequence.

[0091] In this embodiment, firstly, in step S310, when the electromagnetic heating device 100 detects the pot and starts heating, the electromagnetic heating device 100 controls the switching device 5 to turn on for the preset initial turn-on duration, thereby avoiding applying excessive energy at the beginning, preventing a sudden increase in current in the coil 4, and thus reducing the generation of shock and abnormal noise. Subsequently, in step S320, after completing the initial turn-on, the electromagnetic heating device 100 gradually extends the first turn-on duration of the switching device 5 in each turn-on / off cycle according to the actual operating state. By increasing the duration cycle by cycle, the current in the coil 4 can rise or fall smoothly with the operation of the switching device 5, thereby gradually increasing the output power of the electromagnetic heating device 100. This process continues until, finally, at the zero-crossing point of the voltage or current during the half-wave duration of the target power supply, the switching device 5 can be turned on or off according to the preset target turn-on / off sequence. This control method ensures that the switching device 5 operates within a time window close to the actual zero crossing point throughout the entire startup phase of the electromagnetic heating device 100. This effectively suppresses electromagnetic noise and mechanical vibration caused by non-zero-point switching, improves the stability and safety of the electromagnetic heating device 100's operation, and further optimizes the user experience.

[0092] Please see Figure 6 In one embodiment, the electromagnetic heating device 100 further includes a resonant circuit, which includes a resonant capacitor and a coil 4. Step S100B specifically includes:

[0093] S110B: Obtain the capacitance value of the resonant capacitor, the inductance value of the coil, and the turn-on voltage of the switching device.

[0094] S120B, based on the capacitance value of the resonant capacitor, the inductance value of the coil, and the turn-on voltage of the switching device, performs parameter adjustment to determine the preset initial turn-on time.

[0095] In this embodiment, firstly, in step S110B, the electromagnetic heating device 100 acquires the capacitance value of the resonant capacitor, the inductance value of the coil 4, and the turn-on voltage of the switching device 5. Next, in step S120B, based on the acquired capacitance value of the resonant capacitor, the inductance value of the coil 4, and the turn-on voltage of the switching device 5, parameter adjustments are performed to determine the preset initial 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, smoothly, and efficiently during the initial startup phase, while minimizing electromagnetic noise and mechanical vibration. Specifically, from the resonant frequency relationship (where L is the resonant frequency of the resonant circuit, L is the inductance value of the 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 coil 4 jointly determine the operating frequency and resonant characteristics of the electromagnetic heating device 100, thereby affecting the speed and amplitude of current rise during the initial startup phase; while the turn-on voltage of the switching device 5 directly affects the voltage level applied to the coil 4 and the resulting current magnitude. If the initial turn-on duration of the switching device 5 is not set reasonably, for example, if the turn-on time is too long, it may cause the coil 4 to generate excessively high initial current or voltage, thereby causing obvious electromagnetic noise and mechanical vibration of the cookware, and even increasing the switching loss of the switching device 5. On the other hand, if the turn-on time is too short, it may lead to insufficient power output, failure to effectively establish a magnetic field, and affect heating efficiency. Therefore, this embodiment determines the optimal preset initial turn-on duration by comprehensively considering the specific capacitance value of the resonant capacitor, the inductance value of the coil 4, and the turn-on voltage of the switching device 5, and by adjusting these parameters. This duration can avoid insufficient power of the electromagnetic heating device 100 due to an excessively short initial turn-on duration of the switching device 5, and also prevent current surges caused by an excessively long initial turn-on duration of the switching device 5. This ensures that the energy input to the electromagnetic heating device 100 at the moment of startup can avoid mechanical vibration and electromagnetic noise caused by excessively high initial energy, and also ensure sufficient power output to quickly establish a stable high-frequency alternating magnetic field, achieving a fast and efficient heating response. Furthermore, by properly matching and optimizing the above parameters, the service life of the electromagnetic heating equipment 100 can be effectively extended, unnecessary energy loss can be reduced, and its operational stability and reliability can be improved.

[0096] Please see Figure 7 In one embodiment, the noise control method of the electromagnetic heating device 100 further includes:

[0097] S500. Adjust the third on-time, on-interval, or cycle of the switching device according to the material of the cookware.

[0098] It is understandable that different cookware materials have varying effects on the electromagnetic heating device 100, especially since its equivalent impedance changes with variations in the material's magnetic permeability and conductivity, directly affecting the operating 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 cookware material to achieve more precise control and effectively suppress abnormal noise. Specifically, the soft-start interval is defined as the period from the first turn-on moment of the switching device 5 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 time required for the switching device 5 to complete a complete turn-on and turn-off process within this interval.

[0099] Specifically, after the switching device 5 is turned on for the first time, the electromagnetic heating device 100 can acquire the resonant amplitude and frequency of the resonant circuit in real time. If the voltage drop of the resonant circuit after the first turn-on is small, it indicates that the equivalent impedance of the cookware is large, possibly made of a low-resistivity non-magnetic material. In this case, the electromagnetic heating device 100 can extend the third turn-on time, for example, by increasing the first turn-on time in the current on / off cycle, to ensure sufficient energy transfer and maintain efficient heating. At the same time, the on-time interval of the switching device 5 can be appropriately reduced, or the cycle of the switching device 5 can be proportionally increased to make the energy injection more concentrated, further improving heating efficiency and stability. Conversely, if the resonant amplitude drops significantly, it indicates that the equivalent impedance of the cookware is small, possibly made of a high-resistivity or high-magnetic-permeability material. In this case, the third turn-on time can be shortened accordingly, for example, by reducing the first turn-on time in the current on / off cycle, to avoid violent magnetic field fluctuations caused by excessive current changes, thereby reducing the risk of abnormal noise. At the same time, the on-time interval of the switching device 5 can be appropriately increased, or the cycle of the switching device 5 can be proportionally reduced to ensure moderate energy injection and prevent excessive energy input from causing unnecessary noise. In this way, the electromagnetic heating device 100 can adaptively adjust at least one of the third turn-on duration, turn-on interval, or cycle of the switching device 5 according to the different materials of the cookware, ensuring that the switching device 5 can turn on when it is close to the zero point of the voltage, and accelerating the process of the turn-on voltage dropping to zero. This not only improves the heating efficiency, but also reduces the noise level during the start-up process, enhances the stability of the equipment operation, and improves the user experience.

[0100] Please see Figure 8In one embodiment, the electromagnetic heating device 100 further includes a resonant circuit; the step of adjusting the second on-time of the switching device 5 according to the material of the cookware specifically includes:

[0101] S510A, Obtain the resonance amplitude of the resonant circuit;

[0102] S520A: Based on the resonance amplitude of the resonant circuit, adjust the third turn-on duration of the switching device until the turn-on voltage of the switching device drops to zero at the zero-crossing point of the target power supply half-wave duration.

[0103] In this embodiment, the electromagnetic heating device 100 also includes a resonant circuit. To optimize the heating process and reduce noise based on the cookware material, step S500 can be broken down into two steps to adjust the third turn-on duration of the switching device 5. First, in step S510A, the electromagnetic heating device 100 acquires the resonance amplitude of the resonant circuit. The resonance amplitude reflects the influence of the cookware material on the electromagnetic heating process, particularly the change in the cookware's equivalent impedance. Next, in step S520A, based on the acquired 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 drops to zero at the zero-crossing point of the target power supply half-wave duration. Specifically, if the detected resonance amplitude is small, it indicates that the cookware's equivalent impedance is large, and the third turn-on duration can be extended to ensure sufficient energy transfer; conversely, if the resonance amplitude is large, it indicates that the cookware's equivalent impedance is small, and the third turn-on duration can be shortened to avoid sudden current changes causing severe magnetic field fluctuations and potential noise problems. This method in this embodiment not only allows the electromagnetic heating device 100 to smoothly transition from the startup phase to a stable working state, but also enables the switching device 5 to turn on or off when approaching the zero-crossing point of the voltage, thereby effectively reducing the noise level.

[0104] Please see Figure 8 In one embodiment, the resonant amplitude of the resonant circuit is negatively correlated with the third turn-on duration of the switching device 5.

[0105] In this embodiment, the resonance amplitude of the resonant circuit is negatively correlated with the third turn-on duration of the switching device 5. This 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 excessive current changes causing violent magnetic field fluctuations and potential noise problems. This negative correlation ensures that regardless of the material of the cookware, the electromagnetic heating device 100 can smoothly transition to a stable working state during the startup phase by adjusting the third turn-on duration of the switching device 5. Furthermore, during the entire startup process, the switching device 5 can turn on or off near the voltage zero-crossing point, thereby effectively reducing noise levels and improving heating efficiency.

[0106] Please see Figure 9 In one embodiment, step S520A specifically includes:

[0107] S521A: When it is determined that the resonance amplitude of the resonant circuit is not greater than the first preset resonance amplitude, the third turn-on duration of the switching device is increased until the turn-on voltage of the switching device is reduced to zero at the zero-crossing point of the half-wave duration of the target power supply.

[0108] S522A: When it is determined that the resonance amplitude of the resonant circuit is greater than the first preset resonance amplitude, the third turn-on duration of the switching device is reduced until the turn-on voltage of the switching device is reduced to zero at the zero-crossing point of the half-wave duration of the target power supply.

[0109] 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, ensuring the stable operation of the electromagnetic heating device 100. Under this resonance amplitude condition, the magnetic and electrical conductivity of the cookware is moderate, resulting in high energy transfer efficiency. No additional adjustment to the third on-time of the switching device 5 is required to simultaneously meet power output requirements and noise control requirements. In other words, when operating within this amplitude range, the electromagnetic heating device 100 can achieve efficient energy injection to maintain good heating performance without causing drastic magnetic field fluctuations due to sudden current changes, thus avoiding significant electromagnetic noise or mechanical vibration. Therefore, the first preset resonance amplitude can be regarded as a benchmark threshold for the electromagnetic heating device 100 to determine whether the switching device 5 needs adjustment. Only when the obtained resonance amplitude deviates from this ideal range will the adjustment of the third on-time of the switching device 5 be triggered to further optimize the operating state of the electromagnetic heating device 100 and the user experience.

[0110] In this embodiment, step S520A is further refined into two judgment branches, used to adjust the third turn-on duration of the switching device 5 according to the resonance amplitude of the resonant circuit, so as to achieve more precise noise control and heating efficiency optimization. Specifically, in step S521A, when the electromagnetic heating device 100 determines that the resonance amplitude of the resonant circuit is not greater than the first preset resonance amplitude, it indicates that the equivalent impedance of the pot is large (such as using a non-magnetic or thin-walled pot). At this time, the third turn-on duration of the switching device 5 can be increased to improve energy injection and ensure that the turn-on voltage of the switching device 5 can be reduced to zero at the zero-crossing point of the target power supply half-wave duration. In step S522A, if it is determined that the resonance amplitude is greater than the first preset resonance amplitude, it indicates that the equivalent impedance of the pot is small (such as using a pot with high magnetic permeability or thick-walled material). At this time, the third turn-on duration can be reduced to avoid violent magnetic field fluctuations caused by excessive current change rate, thereby reducing the risk of noise, and also ensuring that the voltage is reduced to zero at the zero-crossing point. By using threshold judgment, the electromagnetic heating device 100 can automatically adjust the third turn-on time of the switching device 5 under different cookware material conditions, so that the switching device 5 always works near the actual zero crossing point, effectively suppressing the noise during the start-up process of the electromagnetic heating device 100, while improving heating efficiency and stability.

[0111] Please see Figure 10 In one embodiment, the step of adjusting the opening interval of the switching device according to the material of the cookware specifically includes:

[0112] S510B: When the resonant amplitude of the resonant circuit is determined to reach the second preset resonant amplitude, the switching device is controlled to turn on to adjust the opening interval of the switching device.

[0113] The second preset resonance amplitude is less than the first preset resonance amplitude.

[0114] It should be noted that the second preset resonance amplitude is the minimum resonance amplitude threshold 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 startup, i.e., when the equivalent impedance of the cookware reaches a relatively high level or the material's magnetic permeability is poor. Specifically, the second preset resonance amplitude can reflect the standard of the electromagnetic heating device 100 operating under relatively extreme but still acceptable working conditions. When the resonance amplitude is determined to be close to this threshold, it indicates that the current cookware material has a weak response to the magnetic field and low energy transfer 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 maintain a stable heating effect and a low noise level under low energy transfer conditions.

[0115] In this embodiment, the specific steps for adjusting the opening interval of the switching device 5 according to the cookware material are further refined to adjustment 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 opening interval of the switching device 5, thereby optimizing the energy input method and frequency, ensuring that even under low-efficiency energy transmission conditions, the ideal heating effect can be maintained 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 properties. In this case, increasing the opening interval of the switching device 5 helps to avoid violent magnetic field fluctuations caused by excessively rapid energy injection, thereby reducing the risk of abnormal noise. Through the method of this embodiment, not only can the electromagnetic heating device 100's ability to cope with cookware of different materials be improved, but it can also minimize noise and vibration problems during the start-up process while ensuring efficient energy transmission, further enhancing the user experience and the overall reliability of the device.

[0116] Please see Figure 11 In one embodiment, the noise control method of the electromagnetic heating device 100 further includes:

[0117] S600: Obtain the turn-on voltage of the switching device;

[0118] S700: When the first turn-on duration of the switching device reaches the zero-crossing point 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 turn-on / turn-off cycle of the switching device, and control the switching device to turn on / off according to the target turn-on / turn-off sequence.

[0119] In this embodiment, the noise control method of the electromagnetic heating device 100 further includes steps S600 and S700 to suppress noise generation to the greatest extent while optimizing the operation of the switching device 5. First, in step S600, the electromagnetic heating device 100 acquires the turn-on voltage of the switching device 5, which is crucial for determining when to stop extending the first turn-on duration of the switching device 5. Next, 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 point 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 extending the first turn-on duration in each on / off cycle and precisely control the on / off of the switching device 5 according to the target on / off sequence. This means that the electromagnetic heating device 100 will smoothly transition from the startup phase to the normal heating phase and begin efficiently heating the cookware. The preset turn-on voltage serves as the minimum voltage threshold for the safe and reliable operation of the switching device 5. This ensures stable energy transmission even when the voltage is close to zero or the input voltage is low, preventing switching instability or additional electromagnetic noise due to insufficient voltage. Through this control method, the electromagnetic heating device 100 can not only achieve precise control over the startup process but also reduce the risk of abnormal noise, improving overall equipment operating efficiency and user experience.

[0120] The present invention also proposes an abnormal noise control device 1 for an electromagnetic heating device 100, please refer to [link to relevant documentation]. Figure 12 The noise control device 1 of the electromagnetic heating device 100 includes a memory 11 and a processor 12. The memory 11 is used to store the noise control program of the electromagnetic heating device 100, and the processor 12 is used to execute the noise control program of the electromagnetic heating device 100 to implement the noise control method of the electromagnetic heating device 100 as described above. The specific structure of the noise control method of the electromagnetic heating device 100 refers to the above embodiments. Since the noise control device 1 of the electromagnetic heating device 100 adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described in detail here.

[0121] The present invention also proposes an electromagnetic heating device 100, please refer to [link / reference]. Figure 13 The electromagnetic heating device 100 includes a rectifier and filter circuit 2, a panel 3, a coil 4, and a noise control device 1. The specific structure of the noise control device 1 is as described in the above embodiments. Since the electromagnetic heating device 100 adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0122] The electromagnetic heating device 100 can be an induction cooker, a steaming / cooking device, or a cooking robot, etc., and is not specifically limited. The electromagnetic heating device 100 may include, but is not limited to, a rectifier and filter circuit 2, a panel 3, a switching device 5, a coil 4, and a noise control device 1. The rectifier and filter circuit 2 is used to convert the externally input mains power into stable DC power; the panel 3 is not only used to place cookware but also to enable user interaction; the switching device 5 is used to convert the DC power output from the rectifier and filter circuit 2 into high-frequency AC power; the coil 4 is used to generate a high-frequency alternating magnetic field when the high-frequency AC power passes through it. In practical applications, when the electromagnetic heating device 100 is working, the mains power (e.g., 220V AC) is first converted into DC voltage by the rectifier and filter circuit 2. Because the rectified voltage is processed by capacitor filtering, a DC voltage slightly higher than the peak value of the original AC 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 AC voltage, and the high-frequency AC power generates a high-frequency alternating magnetic field when it passes through the coil 4. When a cookware containing ferromagnetic material is placed on panel 3, the bottom of the pot will cut magnetic lines of force under the influence of a high-frequency alternating magnetic field, generating an induced current. According to the eddy current effect, these induced currents will generate heat energy at the bottom of the pot, thereby heating the food.

[0123] It is worth noting that the noise control device 1 can acquire the target power input frequency and target power input voltage, as well as the target on / off timing of the switching device 5. Based on the acquired target power input frequency and target power input voltage, it determines the target power half-wave duration and the zero-crossing point of the voltage during that half-wave duration. When it is detected that the pot has been placed on the panel 3 of the electromagnetic heating device 100 and has started heating, the noise control device 1 controls the switching device 5 to operate and gradually extends the on-time of the switching device 5 in each on / off cycle. This process continues until, at the zero-crossing point of the target power half-wave duration, the switching device 5 can be precisely controlled to turn on and off according to the preset target on / off timing. Specifically, the switching device 5 can be turned on and off after a preset initial on-time (e.g., 2μs) 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, from 2μs to 3μs, or even further extended to 4μs, etc., and the specific value is not limited. By progressively increasing the on-time period cycle by cycle, the switching device 5 is ultimately able to perform on or off operations according to the target on / off sequence at the zero-crossing point of the target power supply half-wave duration. If the switching device 5 is turned on at the zero-crossing point, it will run for the set on-time period in the target on / off sequence and then turn off; conversely, if the switching device 5 is turned off at the zero-crossing point, it will run for the set off time in the target on / off sequence and then turn on. Regardless of which on / off cycle the switching device 5 is operating in, when the switching device 5 is turned on, the current in the coil 4 increases from zero. Due to the inductance of the 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 coil 4 continues through the freewheeling diode circuit, and the current gradually decreases to zero. With this control method, the current in the 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 abnormal noise caused by the rapid change of current in the coil 4 during the start-up of the electromagnetic heating device 100, and improving the overall performance and user experience of the electromagnetic heating device 100.

[0124] The above are merely exemplary embodiments of the present invention and do not limit the scope of the patent of the present invention. All equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of patent protection of the present invention.

Claims

1. A method for controlling abnormal noise in an electromagnetic heating device, characterized in that, The electromagnetic heating device includes a switching device, and the noise control method of the electromagnetic heating device includes: Obtain the target power input frequency, target power input voltage, and target on / off timing of the switching devices; Based on the obtained target power input frequency and target power input voltage, determine the zero-crossing time of the target power half-wave duration; When the cookware is detected and heating is started, the switching device is controlled to work and the first on-time of the switching device in each on / off cycle is gradually extended until the zero-crossing point of the target power supply half-wave duration is reached. Then, the switching device is controlled to turn on / off according to the target on / off sequence. The steps of obtaining the target power input frequency, target power input voltage, and target on / off timing of the switching devices further include: Get the preset initial activation duration; The step of controlling the switching device to operate and gradually extending the first on-time of the switching device in each on / off cycle when the cookware is detected and heating is started, until the zero-crossing point of the target power supply half-wave duration, and controlling the switching device to turn on / off according to the target on / off sequence specifically includes: When the cookware is detected and heating is started, the control switch is turned on for a preset initial on-time duration; After the switching device is turned on for a preset initial turn-on duration, the first turn-on duration in each turn-on / turn-off cycle of the switching device is gradually extended until the zero-crossing point of the target power supply half-wave duration is reached, at which point the switching device is turned on / off according to the target turn-on / turn-off sequence. The electromagnetic heating device further includes a resonant circuit, which includes a resonant capacitor and a coil. The step of obtaining the preset initial start-up duration specifically includes: Obtain the capacitance value of the resonant capacitor, the inductance value of the coil, and the turn-on voltage of the switching device; Based on the capacitance value of the resonant capacitor, the inductance value of the coil, and the turn-on voltage of the switching device, the parameters are adjusted to determine the preset initial turn-on duration.

2. The noise control method for electromagnetic heating equipment as described in claim 1, characterized in that, The noise control method for the electromagnetic heating device also includes: When heating stops, the second turn-on duration of the switching device is extended according to the half-wave duration of the target power supply until the switching device is turned off at the zero-crossing point of the half-wave duration of the target power supply.

3. The noise control method for electromagnetic heating equipment as described in claim 1, characterized in that, The step of determining the zero-crossing time of the target power supply half-wave duration based on the acquired target power supply input frequency and target power supply input voltage specifically includes: Acquire the target power input frequency, target power input voltage, preset frequency factor, and preset voltage factor; The target frequency influence coefficient is determined based on the target power input frequency and the preset frequency factor, and the target voltage influence coefficient is determined based on the target power input voltage and the preset voltage factor. The zero-crossing time of the target power supply half-wave duration is determined based on the target frequency influence coefficient and the target voltage influence coefficient.

4. The noise control method for an electromagnetic heating device as described in claim 1, characterized in that, The noise control method for the electromagnetic heating device also includes: Based on the material of the cookware, adjust the third turn-on duration, turn-on interval, or period of the switching device. The soft-start interval is defined as the time between the first turn-on of the switching device and the zero-crossing point of the target power supply half-wave duration. The third turn-on duration is the total turn-on duration of the switching device within the soft-start interval. The turn-on interval is the time interval between two consecutive turn-on times of the switching device within the soft-start interval. The period is the time required for the switching device to complete a complete turn-on and turn-off process within the soft-start interval.

5. The noise control method for an electromagnetic heating device as described in claim 4, characterized in that, The step of adjusting the third on-time of the switching device according to the material of the cookware specifically includes: Obtain the resonant amplitude of the resonant circuit; Based on the resonance amplitude of the resonant circuit, the third turn-on duration of the switching device is adjusted until the turn-on voltage of the switching device is reduced to zero at the zero-crossing point of the target power supply half-wave duration.

6. The noise control method for an electromagnetic heating device as described in claim 5, characterized in that, The resonant amplitude of the resonant circuit is negatively correlated with the third turn-on duration of the switching device.

7. The noise control method for an electromagnetic heating device as described in claim 6, 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 the turn-on voltage of the switching device drops to zero at the zero-crossing point of the target power supply half-wave duration specifically includes: When it is determined that the resonance amplitude of the resonant circuit is not greater than the first preset resonance amplitude, the third turn-on duration of the switching device is increased until the turn-on voltage of the switching device is controlled to drop to zero at the zero-crossing point of the half-wave duration of the target power supply. When it is determined that the resonance amplitude of the resonant circuit is greater than the first preset resonance amplitude, the third turn-on duration of the switching device is reduced until the turn-on voltage of the switching device is reduced to zero at the zero-crossing point of the half-wave duration of the target power supply.

8. The noise control method for an electromagnetic heating device as described in claim 7, characterized in that, The step of adjusting the opening interval of the switching device according to the material of the cookware specifically includes: When the resonant amplitude of the resonant circuit is determined to reach the second preset resonant amplitude, the switching device is turned on to adjust the opening interval of the switching device. Wherein, the second preset resonance amplitude is less than the first preset resonance amplitude.

9. The noise control method for an electromagnetic heating device as described in claim 1, characterized in that, The noise control method for the electromagnetic heating device also includes: Obtain the turn-on voltage of the switching device; When the first turn-on duration of the switching device reaches the zero-crossing point of the target half-wave duration, and the turn-on voltage of the switching device reaches the preset turn-on voltage, the extension of the first turn-on duration in each turn-on / turn-off cycle of the switching device is stopped, and the switching device is controlled to turn on / off according to the target turn-on / turn-off sequence.

10. A noise control device, characterized in that, include: Memory; A processor, a noise control program for an electromagnetic heating device stored in the memory and executed by the processor, wherein the noise control program, when executed by the processor, implements the noise control method for an electromagnetic heating device as described in any one of claims 1 to 9.

11. An electromagnetic heating device, characterized in that, Includes the noise control device as described in claim 10.

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