Zero-voltage starting and multi-mode control method of full-area heating electromagnetic stove and related device

Abstract

The application discloses a zero-voltage starting and multi-mode control method of a full-area heating electromagnetic range and related devices, relates to the technical field of electromagnetic heating, and the method comprises the following steps: acquiring an electric network voltage pulsation signal collected by a detection circuit in real time; identifying a voltage zero-crossing moment of a three-phase alternating current power input interface according to the electric network voltage pulsation signal; controlling a relay switch to perform a conduction or disconnection operation at the voltage zero-crossing moment, and controlling an insulated gate bipolar transistor in an inverter circuit to start working when a direct current bus voltage drops to a preset zero-voltage threshold range, so as to complete a soft starting process; after the full-area heating electromagnetic range completes the soft starting, selecting a corresponding power control mode according to a target output power; and controlling the relay switch and the inverter circuit to work according to the selected power control mode, so that a resonant load network outputs a heating power matched with the target output power. The application realizes a full-area heating control effect with low noise, high efficiency and full power coverage.

Description

Technical Field

[0001] This application relates to the field of electromagnetic heating technology, and in particular to a zero-voltage start-up and multi-modal control method and related device for a full-area heating electromagnetic stove. Background Technology

[0002] Induction cooktops with full-area heating typically require a large total output power due to their large heating area and wide coverage. To meet this power requirement, existing power supply solutions mostly use single-phase or three-phase AC power input. Especially under a three-phase 380V power supply architecture, the minimum amplitude of the DC bus voltage output after bridge rectification still exceeds 500V, and this DC bus voltage is a continuous high-voltage waveform, without including a voltage range close to zero volts. Under this high-voltage DC bus power supply condition, the insulated gate bipolar transistors (IGBTs) in the subsequent half-bridge resonant inverter circuit often cannot complete the turn-on at zero voltage during actual startup and operation due to a voltage difference of several hundred volts between their collector and emitter. To adjust the output power, related technologies usually use pulse frequency modulation to adjust the heating power by changing the switching frequency of the IGBT. Under this modulation method, when a smaller output power is required, the switching frequency is increased to a frequency band much higher than the resonant frequency, significantly increasing the switching losses of the IGBT and drastically reducing the heating efficiency. More importantly, when the IGBT is turned on with a high DC bus voltage and a non-zero voltage, there is a large spike in the collector current each time it is turned on. This spike current excites the resonant coil to generate high-frequency mechanical vibration. After the vibration frequency is superimposed on the coil's natural frequency, it radiates outward through the bottom of the pot, forming a "knocking" sound that can be clearly perceived by the user, which seriously affects the user experience.

[0003] Furthermore, induction cooktops with full-area heating typically contain multiple induction heating coils, each corresponding to a different heating zone. Since the materials, sizes, and required heating power of the cookware placed in each zone often vary in actual use, each coil needs to have its operating frequency adjusted independently. Simultaneously, the physical distance between the coils is extremely close, resulting in significant electromagnetic coupling effects. When multiple coils operate simultaneously at different frequencies, their mutual modulation generates differential frequency interference. When this differential frequency falls within the range of human hearing, it can easily cause a piercing whistling sound, and traditional power adjustment strategies using a single frequency modulation method are insufficient to effectively eliminate this problem.

[0004] In summary, existing induction cookers with full-area heating still have significant shortcomings in terms of high-voltage safe start-up and shutdown, acoustic comfort when multiple coils are working simultaneously, and continuous heating across the entire power range. These technical issues urgently need to be systematically addressed. Summary of the Invention

[0005] The purpose of this application is to provide a zero-voltage start-up and multi-modal control method and related device for a full-zone heating induction cooker, which can achieve a full-zone heating control effect with low noise, high efficiency and full power coverage.

[0006] To achieve the above objectives, this application provides the following solution: In a first aspect, this application provides a zero-voltage start-up and multi-mode control method for a full-zone heating induction cooker. The zero-voltage start-up and multi-mode control device for the full-zone heating induction cooker includes a three-phase AC power input interface, an AC switching circuit, a rectifier filter circuit, an inverter circuit, a resonant load network, a detection circuit, and a microcontroller unit connected in sequence. The AC switching circuit includes a relay switch disposed on one phase voltage line of the three-phase AC power input interface. The method is applied to the microcontroller unit, including: The detection circuit acquires the real-time grid voltage pulsation signal. The zero-crossing point of the voltage at the three-phase AC power input interface is identified based on the grid voltage pulsation signal. At the zero-crossing point of the voltage, the relay switch is controlled to perform an on or off operation so that the DC bus voltage output by the rectifier filter circuit presents a periodic pulsating waveform. When the DC bus voltage drops to a preset zero voltage threshold range, the insulated gate bipolar transistor in the inverter circuit is controlled to start working to complete the soft start process. After the induction cooker with full-zone heating completes its soft start, the corresponding power control mode is selected according to the target output power; the power control modes include low-power intermittent working mode, multi-coil coordinated power adjustment mode and high-power full-voltage power supply mode; The relay switch and the inverter circuit are controlled according to the selected power control mode so that the resonant load network outputs heating power that matches the target output power.

[0007] Secondly, this application provides a zero-voltage start-up and multi-mode control device for a full-area heating induction cooker, the device comprising: Three-phase AC power input interface, used for connecting a three-phase AC power source; An AC switching circuit is connected to the output terminal of the three-phase AC power input interface. The AC switching circuit includes a main circuit relay, which is set on one phase voltage line of the three-phase AC power input interface. The main circuit relay is used to controllably connect or disconnect the one phase voltage line. A rectifier and filter circuit is connected to the output terminal of the AC switching circuit. The rectifier and filter circuit is used to convert the AC power output by the AC switching circuit into DC power and perform filtering to output DC bus voltage. The detection circuit is connected to the three-phase AC power input interface and the output terminal of the rectifier filter circuit, respectively. The detection circuit is used to collect the grid voltage pulsation signal and the voltage and current parameters of the DC bus voltage. An inverter circuit is connected to the output terminal of the rectifier filter circuit. The inverter circuit includes multiple inverter units, each of which includes an upper bridge arm insulated gate bipolar transistor and a lower bridge arm insulated gate bipolar transistor. Each inverter unit is used to convert the DC bus voltage into high-frequency AC power according to the drive signal. A resonant load network is connected to the output terminal of the inverter circuit. The resonant load network includes multiple induction heating coils, each of which is connected to a corresponding inverter unit. Each induction heating coil is used to convert the high-frequency alternating current into an alternating magnetic field to heat the cookware placed on the induction heating coil. The microcontroller unit is connected to the AC switching circuit, the detection circuit, and the inverter circuit respectively. The microcontroller unit is used to receive the grid voltage pulsation signal, the voltage parameters, and the current parameters collected by the detection circuit, and to identify the voltage zero-crossing point based on the grid voltage pulsation signal. At the voltage zero-crossing point, the microcontroller unit outputs a first control signal to the AC switching circuit to control the conduction or disconnection of the main circuit relay, and outputs a second control signal to the inverter circuit to control the operating frequency and drive signal duty cycle of the insulated gate bipolar transistor in each inverter unit.

[0008] Thirdly, this application provides a microcontroller unit, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the zero-voltage start-up and multi-modal control method for the full-zone heating induction cooker described in any one of the above-mentioned methods.

[0009] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the zero-voltage start-up and multi-modal control method for the all-zone heating induction cooker described above. Fifthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements the zero-voltage start-up and multi-modal control method for the all-zone heating induction cooker described above.

[0010] According to the specific embodiments provided in this application, this application has the following technical effects: This application provides a zero-voltage start-up and multi-mode control method and related apparatus for a full-area heating induction cooker. First, it acquires the grid voltage pulsation signal and identifies the voltage zero-crossing point. Then, at this zero-crossing point, it controls a relay switch to perform an on or off operation, causing the DC bus voltage output by the rectifier filter circuit to exhibit a periodic pulsating waveform. When the DC bus voltage drops to a preset zero-voltage threshold range, it controls the insulated-gate bipolar transistor (IGBT) to start operating. Through this control, the DC bus voltage, which was originally continuously at a high voltage level, is transformed into a pulsating voltage with a periodic zero-voltage range. This fully utilizes the inherent zero-crossing characteristics of three-phase AC power, creating a start-up window for the IGBT where the voltage stress approaches zero. The startup process is completed within this window, enabling the insulated gate bipolar transistor (IGBT) to achieve zero-voltage turn-on under conditions of extremely low voltage difference between the collector and emitter. This eliminates the impact excitation of the resonant coil by the collector current spike under high-voltage hard switching conditions, avoids high-frequency mechanical vibration of the coil and the resulting "knocking" sound, and significantly reduces the turn-on loss and voltage stress of the switching transistor, thereby significantly improving the operational reliability and service life of the IGBT.

[0011] Based on this, after the induction cooker with full-zone heating achieves zero-voltage start-up and the multi-mode control device completes soft start-up, the corresponding power control mode is selected according to the target output power. The relay switch and inverter circuit are then controlled according to the selected power control mode to ensure that the resonant load network output matches the target output power. By integrating three different power adjustment strategies—low-power gap operation mode, multi-coil coordinated power adjustment mode, and high-power full-voltage power supply mode—under a single control architecture, the induction cooker with full-zone heating has an adaptable power adjustment path across the entire power range. This effectively overcomes the inherent defects of traditional pulse frequency modulation methods, which rely solely on frequency changes across the entire frequency band, resulting in high switching losses and low heating efficiency in the low-power range. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 A schematic diagram of the functional modules of a zero-voltage start-up and multi-modal control device for a full-area heating induction cooker provided in Embodiment 1 of this application; Figure 2 A flowchart illustrating a zero-voltage start-up and multi-modal control method for a full-area heating induction cooker provided in Embodiment 1 of this application; Figure 3This is a schematic diagram of a microcontroller unit provided in Embodiment 3 of this application.

[0014] Figure label: 1-Three-phase AC power input interface; 2-AC switching circuit; 3-Rectifier and filter circuit; 4-Inverter circuit; 5-Resonant load network; 6-Detection circuit; 7-Micro control unit. Detailed Implementation

[0015] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0016] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0017] Example 1 The zero-voltage start-up and multi-mode control method for a full-zone heating induction cooker provided in this application embodiment can be applied to the microcontroller unit in a zero-voltage start-up and multi-mode control device for a full-zone heating induction cooker. For example... Figure 1 As shown, the zero-voltage start and multi-mode control device for the all-zone heating induction cooker includes a three-phase AC power input interface, an AC switching circuit, a rectifier filter circuit, an inverter circuit, a resonant load network, a detection circuit, and a microcontroller unit connected in sequence. The AC switching circuit includes a relay switch installed on one phase voltage line of the three-phase AC power input interface. Figure 2 As shown, a zero-voltage start-up and multi-modal control method for a full-zone heating induction cooker is provided. This method is executed by a microcontroller unit and includes the following steps 201 to 205. Wherein: Step 201: Acquire the grid voltage pulsation signal collected in real time by the detection circuit.

[0018] Step 202: Identify the zero-crossing point of the voltage at the three-phase AC power input interface based on the grid voltage pulsation signal.

[0019] Step 203: At the zero-crossing point of the voltage, control the relay switch to perform the on or off operation to switch the three-phase AC input power supply to the single-phase AC input power supply state, so that the DC bus voltage output by the rectifier and filter circuit presents a periodic pulsating waveform, and when the DC bus voltage drops to the preset zero voltage threshold range, control the insulated gate bipolar transistor in the inverter circuit to start working, thus completing the soft start process.

[0020] Step 204: After the induction cooker with full-area heating completes the soft start, select the corresponding power control mode according to the target output power; the power control modes include low power intermittent working mode, multi-coil coordinated power adjustment mode and high power full voltage power supply mode.

[0021] Step 205: Control the relay switch and inverter circuit to operate according to the selected power control mode so that the heating power output of the resonant load network matches the target output power.

[0022] By implementing steps 201 to 205 above, this embodiment has the following beneficial effects: First, the grid voltage pulsation signal is acquired and the zero-crossing point is identified. Then, at this zero-crossing point, a relay switch is controlled to perform a conduction or disconnection operation, switching the three-phase AC input power supply to a single-phase AC input state. This causes the DC bus voltage output by the rectifier and filter circuit to exhibit a periodic pulsating waveform. When the DC bus voltage drops to a preset zero-voltage threshold range, the insulated-gate bipolar transistor (IGBT) is controlled to start operating. Through this control, the DC bus voltage, which was originally continuously at a high voltage level, is transformed into a pulsating voltage with a periodic zero-voltage range. This fully utilizes the inherent zero-crossing characteristics of three-phase AC power, creating a startup window for the IGBT where voltage stress approaches zero. The startup action is completed within this window, enabling the IGBT to achieve zero-voltage turn-on under extremely low voltage difference between the collector and emitter. This fundamentally eliminates the impact excitation of the resonant coil by the collector current spike under high-voltage hard switching conditions, avoiding high-frequency mechanical vibration of the coil and the resulting "knocking" sound. Simultaneously, it significantly reduces the turn-on loss and voltage stress of the switching transistor, significantly improving the operational reliability and service life of the IGBT.

[0023] Based on this, after the induction cooker with full-zone heating achieves zero-voltage start-up and the multi-mode control device completes soft start-up, the corresponding power control mode is selected according to the target output power. The relay switch and inverter circuit are then controlled according to the selected power control mode to ensure that the resonant load network output matches the target output power. By integrating three different power adjustment strategies—low-power gap operation mode, multi-coil coordinated power adjustment mode, and high-power full-voltage power supply mode—under a single control architecture, the induction cooker with full-zone heating has an adaptable power adjustment path across the entire power range. This effectively overcomes the inherent defects of traditional pulse frequency modulation methods, which rely solely on frequency changes across the entire frequency band, resulting in high switching losses and low heating efficiency in the low-power range.

[0024] Furthermore, steps 201-203 constitute the soft-start control process for the whole-area heating induction cooker. The soft-start control process is specifically as follows: After the system is powered on and initialized, the microcontroller unit first acquires the grid voltage pulsation signal in real time through the detection circuit, and identifies the zero-crossing point of the voltage at the three-phase AC power input interface based on the grid voltage pulsation signal.

[0025] In a three-phase 380V power supply system, the DC bus voltage output by the rectifier and filter circuit is originally continuous. After identifying the voltage zero-crossing point, the microcontroller controls a relay switch to perform an on / off operation at that point, switching the three-phase AC power supply to a single-phase AC power input state. Specifically, the microcontroller controls the relay switch to perform an on / off switch once every at least two power frequency cycles at the voltage zero-crossing point, causing one phase voltage line of the three-phase AC power input interface to be periodically connected or disconnected in each switching cycle, forming a DC bus voltage pulsating waveform with a frequency twice the power frequency at the output of the rectifier and filter circuit; the switching cycle is at least two power frequency cycles. The time interval between two adjacent on / off switching operations is greater than the inherent operating time of the relay switch, and the time interval between two adjacent off / off switching operations is also greater than the inherent operating time of the relay switch; the inherent operating time is the time required for the relay switch to complete the switching from receiving the switching command to the completion of the contact state switching. For example, when the grid frequency is 50Hz, the DC bus voltage output by the rectifier filter circuit is controlled to be a 100Hz pulsating waveform, so that its minimum value is close to zero volts.

[0026] Furthermore, the technical solution provided in this application is also applicable to induction cookers using single-phase AC power input. For single-phase AC power, the DC bus voltage output after rectification and filtering is itself a periodic pulsating waveform, naturally possessing a periodic voltage range close to zero volts. Therefore, there is no need to install a relay switch on the AC input side; this zero-crossing range can be directly utilized to achieve zero-voltage start-up and intermittent operation control of the insulated-gate bipolar transistor. Its implementation principle is completely consistent with the control logic in the single-phase power supply state when the relay is disconnected in a three-phase scheme. Therefore, the application scenarios of single-phase AC power also fall within the protection scope of this application.

[0027] Through the aforementioned periodic chopping control, the DC bus voltage output by the rectifier and filter circuit exhibits a periodic pulsating waveform. When the DC bus voltage drops to a preset zero-voltage threshold range, the microcontroller controls the insulated-gate bipolar transistor (IGBT) in the inverter circuit to start operating, completing the soft-start process. By utilizing the moment when the DC bus voltage approaches zero volts to control the IGBT to start operating, soft-start under zero-voltage conditions is achieved. The inverter circuit can be a half-bridge inverter circuit or a full-bridge inverter circuit.

[0028] During the soft-start process, the microcontroller unit acquires the operating voltage phase signal and operating current phase signal of the inverter circuit in real time, and determines whether the insulated-gate bipolar transistor (IGBT) is in a zero-voltage state based on these signals. If the determination result indicates that the IGBT is not in a zero-voltage state, the output timing of the inverter circuit's drive signals is adjusted until the IGBT is turned on in a zero-voltage state.

[0029] Soft-start also requires controlling the operating state of the insulated-gate bipolar transistor (IGBT). For inverter circuits, the duty cycle of the IGBT on the upper arm of the half-bridge starts at 0 and gradually increases to about 45%, with the entire soft-start time being 2.5~4ms. Soft-turn occurs approximately 4~2.5ms after the bus voltage approaches zero, at which point the duty cycle of the IGBT on the upper arm of the half-bridge is gradually reduced until it turns off near zero voltage.

[0030] Once the induction cooker has completed its soft start-up, the microcontroller unit determines whether the relay switch remains engaged based on the power requirements and selects the corresponding power control mode according to the target output power.

[0031] Further, step 204 is the power control mode selection process, which specifically includes: The microcontroller unit stores power thresholds in advance. After the induction cooker with full-zone heating completes a soft start, the microcontroller unit obtains the target output power, compares the target output power with the preset power threshold, and selects the corresponding power control mode based on the comparison result and the current working status of the heating area.

[0032] Specifically, when the target output power is less than the power threshold, the microcontroller selects the low-power gap operating mode. When multiple heating zones of the full-zone heating induction cooker are working simultaneously and the target output power is greater than or equal to the power threshold, the microcontroller selects the multi-coil coordinated power adjustment mode. When the target output power is greater than or equal to the power threshold and a single heating zone is working independently, the microcontroller selects the high-power full-voltage power supply mode.

[0033] Furthermore, when the selected power control mode is the low-power gap operating mode, the microcontroller executes the following control steps: First, the microcontroller controls the relay switch to remain open in order to maintain the pulsating characteristics of the DC bus voltage.

[0034] Secondly, the microcontroller uses the time interval between two adjacent zero-crossing points as the gap duty cycle reference. Within the gap duty cycle reference, the microcontroller determines whether the DC bus voltage has dropped to a preset zero-voltage threshold range based on the current amplitude of the DC bus voltage. When the DC bus voltage drops to the zero-voltage threshold range, the microcontroller determines the time corresponding to the DC bus voltage dropping to the zero-voltage threshold range as the startup time, and controls the insulated-gate bipolar transistor to start working at the startup time.

[0035] Then, the microcontroller calculates the single-operation duration and single-interval duration based on the target output power. Specifically, the microcontroller uses an integer multiple of the period at the voltage zero-crossing point as the time length corresponding to a single step. It calculates the number of steps corresponding to the single-operation duration based on the ratio of the target output power to the rated output power, and calculates the number of steps corresponding to the single-interval duration based on the difference between the rated output power and the target output power divided by the rated output power. The single-operation duration is obtained by multiplying the number of steps corresponding to the single-operation duration by the time length corresponding to the single step; similarly, the single-interval duration is obtained by multiplying the number of steps corresponding to the single-interval duration by the time length corresponding to the single step. The step unit is, for example, 10ms. Both the single-operation duration and the single-interval duration are integer multiples of the DC bus voltage pulsation period, thus ensuring that the start and stop points of each operating period are at the zero-crossing voltage point of the DC bus voltage (therefore, the start and stop points are defined as soft-start and soft-stop times). To provide a better user experience (so that users don't notice the intermittent operation), the downtime for each interval cycle should not exceed 100ms.

[0036] Finally, the microcontroller unit, starting from the startup time, controls the insulated-gate bipolar transistor (IGBT) to operate continuously for the duration of a single operation. Once the continuous operation time reaches the duration of a single operation, the microcontroller unit stops the IGBT. Then, starting from the moment the IGBT stops operating, the microcontroller unit keeps the IGBT in a stopped state for the duration of a single interval. Once the duration of the stopped state reaches the duration of a single interval, the microcontroller unit returns to the step of determining the startup time as the moment when the DC bus voltage drops to the zero voltage threshold range, thus controlling the IGBT to periodically start and stop.

[0037] For example, when the mains frequency is 50Hz, the rectified pulsation frequency is 100Hz. The microcontroller unit (MCU) controls the circuit in steps of multiples of 10ms. If the calculated single-operation duration is 20ms, the MCU stops operating after two voltage zero-crossing moments. If the calculated single-interval duration is 80ms, the MCU waits for eight voltage zero-crossing moments after stopping before restarting, and so on. To increase output power, the single-operation duration is lengthened and the single-interval duration is shortened; conversely, to decrease output power, the single-operation duration is shortened and the single-interval duration is lengthened. All these durations are calculated based on the voltage zero-crossing moments and the mains frequency. Because the insulated-gate bipolar transistor (IGBT) starts and stops at zero voltage, it consumes minimal energy, resulting in very little knocking noise during startup and shutdown. Furthermore, utilizing the thermal inertia of heating, the user experiences no noticeable cessation of heating.

[0038] Throughout the low-power gap operation mode, the microcontroller unit acquires the operating voltage and current phase signals of the inverter circuit in real time. Based on these signals, it determines whether the insulated-gate bipolar transistor (IGBT) is in a zero-voltage state during turn-on. If the result indicates that the IGBT is not in a zero-voltage state, the timing of the inverter circuit's drive signals is adjusted until the IGBT is turned on at zero voltage.

[0039] Furthermore, when the selected power control mode is multi-coil coordinated power regulation mode, the microcontroller executes the following control steps: First, the microcontroller unit acquires the material type information of the cookware placed on the heating coil corresponding to each heating zone. This material type information is determined based on the current value on the heating coil and the DC bus current value. Then, multiple heating zones are grouped according to the material type information, with heating zones corresponding to cookware of the same material type grouped into the same cookware group. The microcontroller unit further groups the cookware materials according to a preset state based on the detected cookware type.

[0040] Secondly, the microcontroller acquires a preset initial operating frequency and controls the inverter circuits in each cookware group to synchronously reduce the frequency from the initial operating frequency, while simultaneously acquiring the real-time heating power of each heating zone during the frequency reduction process. Specifically, if the groups are the same, the microcontroller first controls the frequency reduction operation after the soft start is completed until each heating zone reaches the preset power value.

[0041] When the real-time heating power of each heating zone fails to reach its corresponding preset power value, the microcontroller continues to execute the step of controlling the inverter circuit in each cookware group to synchronously reduce the frequency from the initial operating frequency.

[0042] When the real-time heating power of the first heating zone reaches the corresponding preset power value before the second heating zone, in order to prevent the power of the first heating zone from continuing to rise, the operating frequency of the first heating zone is kept constant. At the same time, the microcontroller unit obtains the current actual operating frequencies of the first and second heating zones, and the operating frequency of the second heating zone continues to decrease. When the difference between the current actual operating frequency of the second heating zone and the operating frequency of the first heating zone reaches 1kHz, the inverter circuit corresponding to the first heating zone is controlled to follow the inverter circuit corresponding to the second heating zone to maintain the 1kHz operating frequency difference and continue to reduce the frequency to the actual operating frequency. At the same time, the duty cycle of the drive signal of the inverter circuit corresponding to the first heating zone is reduced or the dead time is increased so that the real-time heating power of the first heating zone is maintained at the corresponding preset power value.

[0043] During the process of synchronously reducing the frequency of the inverter circuits in each cookware group from the initial operating frequency, the microcontroller also performs the following differential frequency howling cancellation control: The microcontroller unit acquires the actual operating frequency of the inverter circuit corresponding to each heating area, calculates the difference in actual operating frequency between any two heating areas operating simultaneously, and determines whether this difference falls within a preset range of frequencies sensitive to human hearing. When the difference falls within this range (e.g., 1kHz to 17kHz), the microcontroller unit adjusts the duty cycle of the drive signal of the inverter circuit corresponding to at least one heating area to shift the difference out of this range. Because the difference frequency sound does not fall within the range of human hearing sensitivity, feedback caused by coil inductance is avoided.

[0044] Throughout the multi-coil coordinated power regulation mode, the microcontroller unit acquires the operating voltage phase signal and operating current phase signal of the inverter circuit in real time. Based on these signals, it determines whether the insulated-gate bipolar transistor (IGBT) is in a zero-voltage state during turn-on, obtaining the result. If the result indicates that the IGBT is not in a zero-voltage state during turn-on, the output timing of the inverter circuit's drive signal is adjusted until the IGBT is turned on at zero voltage.

[0045] Furthermore, when the selected power control mode is high-power full-voltage supply mode, the microcontroller executes the following control steps: First, the microcontroller controls the relay switch to remain engaged, ensuring the rectifier and filter circuit outputs a full-amplitude DC bus voltage. If a cookware or heating zone is set to a higher power, the AC input relay is engaged after the soft start, restoring the DC bus voltage output by the rectifier and filter circuit to full voltage, thereby increasing the overall system output power while the operating state of the insulated-gate bipolar transistor remains almost unchanged.

[0046] Secondly, the microcontroller unit acquires the target sub-power corresponding to each heating zone, and controls the operating frequency and drive signal duty cycle of the inverter circuit corresponding to each heating zone according to the target sub-power.

[0047] Then, the microcontroller unit acquires the real-time heating power of each heating zone and determines whether each real-time heating power exceeds its corresponding target sub-power.

[0048] When the real-time heating power of any heating zone exceeds the corresponding target sub-power, the microcontroller first reduces the operating frequency and then acquires the real-time heating power again. If the real-time heating power still exceeds the target sub-power after reducing the operating frequency, it then reduces the duty cycle of the drive signal and acquires the real-time heating power again.

[0049] If, after reducing the operating frequency and the drive signal duty cycle are both completed, the real-time heating power still exceeds the target sub-power, the control relay switch is opened, the operating frequency and drive signal duty cycle are readjusted, and the real-time heating power is acquired again after readjustment. If the readjusted real-time heating power still exceeds the target sub-power, the system switches to a low-power interval operating mode based on the current operating frequency and current drive signal duty cycle, ensuring that the average output power meets the preset power requirement.

[0050] Throughout the high-power full-voltage power supply mode, the microcontroller unit acquires the operating voltage phase signal and operating current phase signal of the inverter circuit in real time. Based on these signals, it determines whether the insulated-gate bipolar transistor (IGBT) is in a zero-voltage state during turn-on. If the result indicates that the IGBT is not in a zero-voltage state during turn-on, the output timing of the inverter circuit's drive signals is adjusted until the IGBT is turned on at zero voltage.

[0051] The beneficial effects of selecting the appropriate power control mode based on the target output power are as follows: (1) When the selected power control mode is the low-power gap operation mode, the control relay switch is kept in the open state to maintain the pulsating characteristics of the DC bus voltage, and the insulated gate bipolar transistor is controlled to start working only at the start time corresponding to the DC bus voltage dropping to the preset zero voltage threshold range. At the same time, it is also in the zero voltage state when it stops working. Since all the start and stop actions of the insulated gate bipolar transistor occur during the period when the DC bus voltage approaches zero, the voltage stress and current surge during each start and stop process are suppressed to the minimum level, and the power switching device hardly generates additional switching losses and mechanical shock noise at the start and stop. On this basis, the single working time and single gap time are calculated according to the target output power, and are set in the step unit of an integer multiple of the voltage zero crossing point. Energy is delivered to the resonant load network only during the single working time, and the power output is completely stopped during the single gap time. This intermittent energy transfer method allows for precise matching of average output power with the target output power. This achieves continuous stepless adjustment within the low-power range while avoiding the significant increase in switching losses caused by raising the switching frequency far above the resonant frequency band to reduce output power. Simultaneously, since power output completely stops during the interval, the power switching devices and resonant load network do not incur any losses during this period. The overall heating efficiency of the system is significantly improved compared to traditional high-frequency power reduction methods. Furthermore, users cannot perceive the intermittent power output interruption due to heating thermal inertia, ensuring user comfort under low-power conditions.

[0052] (2) When the selected power control mode is the multi-coil coordinated power adjustment mode, by acquiring the material type information of the cookware corresponding to each heating zone, the heating zones corresponding to cookware of the same material type are divided into the same cookware group, and the inverter circuit in each cookware group is controlled to synchronously reduce the frequency from the initial working frequency. Since each heating zone in the same group adopts the same frequency reduction trajectory, the working frequency of each zone is always consistent, fundamentally eliminating the source of frequency difference interference caused by frequency difference. When the real-time heating power of a certain heating zone reaches the preset power value before other zones in the same group, the inverter circuit corresponding to that zone is controlled to continue to reduce the frequency following other zones, and at the same time, the duty cycle of the drive signal of that zone is reduced or the dead time is increased, so that the working frequency of that zone is kept at the same frequency as other zones in the same group, and the output power of each zone is independently adjusted by using the duty cycle. Simultaneously, during the synchronous frequency reduction process, the actual operating frequency difference between any two simultaneously operating heating areas is calculated in real time. When this difference falls within the preset range of frequencies sensitive to the human ear, the duty cycle of the drive signal corresponding to at least one heating area is adjusted to shift the actual operating frequency difference out of the range of frequencies sensitive to the human ear, ensuring that the operating frequency difference of each circuit is strictly controlled within 1kHz or above 17kHz. This method achieves independent and precise control of the heating power of each area while ensuring the consistency of the multi-coil frequencies to eliminate differential frequency feedback, thus balancing acoustic comfort and power adjustment flexibility.

[0053] (3) When the selected power control mode is the high-power full-voltage power supply mode, the control relay switch is kept in the energized state so that the rectifier filter circuit outputs the full voltage amplitude DC bus voltage, providing sufficient power output capability for each heating zone. On this basis, if the real-time heating power exceeds the target sub-power and cannot be reduced back to the target sub-power by lowering the operating frequency and drive signal duty cycle, the control relay switch is opened and the operating frequency and duty cycle are readjusted. If it still exceeds the target sub-power after readjustment, it switches to the low-power intermittent working mode. This multi-level backoff mechanism uses power supply voltage adjustment as the first-level power control means, frequency and duty cycle adjustment as the second-level fine adjustment means, and intermittent working mode as the third-level fallback solution, so that the system establishes a smooth transition power adjustment link between high-power output demand and low-power precise control, ensuring that the induction cooker with full-area heating can obtain the optimal control strategy matching under any power demand.

[0054] (4) In addition, during the soft start process and throughout the entire process of controlling the inverter circuit according to the selected power control mode, the working voltage phase signal and working current phase signal of the inverter circuit are acquired in real time. Based on the working voltage phase signal and working current phase signal, it is determined whether the turn-on time of the insulated gate bipolar transistor is in a zero-voltage state. If it is not in a zero-voltage state, the output timing of the drive signal of the inverter circuit is adjusted until the insulated gate bipolar transistor is turned on in a zero-voltage state. This full-condition zero-voltage switching guarantee strategy runs through all stages of system startup, low-power intermittent operation, multi-coil coordinated power adjustment and high-power full-voltage power supply, effectively reducing the switching stress of the insulated gate bipolar transistor, extending the life of components, and enabling the system to operate stably and efficiently when facing different cookware materials and different power requirements.

[0055] In summary, this application constructs a DC bus zero-voltage range through relay chopper control at the voltage zero-crossing point, and combines this with multi-mode power control selection and execution after soft start. This ensures the zero-voltage turn-on condition of the insulated-gate bipolar transistor during startup, fundamentally eliminating the "knocking" noise and switching losses caused by high-voltage hard switching. During operation, a low-power intermittent working mode achieves efficient, low-noise, continuous stepless adjustment in the low-power range. A multi-coil coordinated power adjustment mode eliminates the howling caused by the differential frequency effect when multiple coils operate simultaneously. A high-power full-voltage power supply mode and a multi-stage backoff mechanism ensure smooth coverage and precise control across the entire power range. A full-condition zero-voltage switching guarantee strategy enhances system reliability and adaptability. This application systematically solves the technical problems of existing full-zone heating induction cookers in terms of high-voltage start-up and shutdown noise, multi-coil differential frequency howling, and efficiency loss across the entire power range, achieving low-noise, high-efficiency, and full-power coverage full-zone heating control.

[0056] Example 2 Based on the same inventive concept, this application also provides a processing device for implementing the zero-voltage start-up and multi-modal control method for the all-zone heating induction cooker described above. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations in one or more processing device embodiments provided below can be found in the above-described limitations regarding the zero-voltage start-up and multi-modal control device for the all-zone heating induction cooker, and will not be repeated here.

[0057] This application provides a zero-voltage start and multi-mode control device for a full-area heating induction cooker, such as... Figure 1 As shown, the device includes: a three-phase AC power input interface 1, an AC switching circuit 2, a rectifier and filter circuit 3, an inverter circuit 4, a resonant load network 5, a detection circuit 6, and a microcontroller unit 7.

[0058] Three-phase AC power input interface 1 is used to connect to a three-phase AC power source, typically 380V three-phase AC power.

[0059] AC switch circuit 2 is connected to the output terminal of three-phase AC power input interface 1. AC switch circuit 2 includes a main circuit relay and auxiliary switching elements. The main circuit relay is located on one phase voltage line of the three-phase AC power input interface 1 and is used to controllably connect or disconnect that phase voltage line. The control terminal of this relay is connected to the input / output port of microcontroller unit 7 and is subject to the logic control of microcontroller unit 7.

[0060] The rectifier and filter circuit 3 is connected to the output terminal of the AC switching circuit 2. The rectifier and filter circuit 3 consists of a bridge rectifier and a large-capacity filter capacitor. It is used to convert the AC power output from the AC switching circuit 2 into DC power and perform smoothing and filtering to output DC bus voltage.

[0061] The detection circuit 6 is connected to both the three-phase AC power input interface 1 and the output of the rectifier and filter circuit 3. The detection circuit 6 includes a mains voltage zero-crossing detection circuit and a DC bus voltage / current sampling circuit. The mains voltage zero-crossing detection circuit monitors the voltage waveform of the three-phase AC power input interface 1 in real time and transmits the mains voltage pulsation signal to the analog-to-digital sampling port or comparator input port of the microcontroller unit 7. The DC bus voltage / current sampling circuit acquires the voltage and current parameters of the DC bus voltage.

[0062] Inverter circuit 4 is connected to the output of rectifier-filter circuit 3. Inverter circuit 4 includes multiple inverter units, each of which contains an upper-arm insulated-gate bipolar transistor (IGBT) and a lower-arm IGBT, as well as a matching drive circuit. The input of each inverter unit is connected to the output of rectifier-filter circuit 3, i.e., the DC bus. Each inverter unit is used to convert the DC bus voltage into high-frequency alternating current according to the drive signal.

[0063] The resonant load network 5 is connected to the output of the inverter circuit 4. The resonant load network 5 includes multiple induction heating coils, each connected to a corresponding inverter unit. Each induction heating coil converts high-frequency alternating current into an alternating magnetic field to heat the cookware placed on it. Each induction heating coil corresponds to a heating area.

[0064] The microcontroller unit 7 is connected to the AC switching circuit 2, the detection circuit 6, and the inverter circuit 4, respectively. The microcontroller unit 7 receives the grid voltage pulsation signal, DC bus voltage parameters, and current parameters collected by the detection circuit 6, and identifies the voltage zero-crossing point based on the grid voltage pulsation signal. At the voltage zero-crossing point, the microcontroller unit 7 outputs a first control signal to the AC switching circuit 2 to control the on / off state of the main circuit relay, and outputs a second control signal to the inverter circuit 4 to control the operating frequency and drive signal duty cycle of the insulated-gate bipolar transistors in each inverter unit.

[0065] Preferably, each inverter unit of the inverter circuit 4 and each induction heating coil of the resonant load network 5 are connected independently in a one-to-one correspondence manner. Each induction heating coil is independently connected to the output terminal of its corresponding inverter unit. The microcontroller unit 7 outputs its corresponding second control signal independently for each inverter unit to achieve independent control of the heating power of each induction heating coil.

[0066] Example 3 In one exemplary embodiment, a microcontroller unit is provided, which may be a server or a terminal, and its internal structure diagram may be as follows. Figure 3 As shown, the microcontroller unit includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operating system and computer programs in the non-volatile storage media. The database stores processed data. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communicating with external terminals via a network. When the computer program is executed by the processor, it implements a zero-voltage start-up and multi-modal control method for a full-zone heating induction cooker.

[0067] Figure 3 The structures shown are merely block diagrams of a portion of the structures related to the present application and do not constitute a limitation on the microcontroller unit to which the present application is applied. A specific microcontroller unit may include more or fewer components than shown in the figures, or combine certain components, or have different component arrangements. In an exemplary embodiment, a microcontroller unit is provided, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0068] In one exemplary embodiment, a computer-readable storage medium is provided storing a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0069] In one exemplary embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0070] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM).

[0071] The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0072] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0073] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for zero-voltage start-up and multi-modal control of a full-zone heating induction cooker, characterized in that, The zero-voltage start and multi-mode control device for the induction cooker with full-area heating includes a three-phase AC power input interface, an AC switch circuit, a rectifier filter circuit, an inverter circuit, a resonant load network, a detection circuit, and a microcontroller unit connected in sequence. The AC switch circuit includes a relay switch installed on one phase voltage line of the three-phase AC power input interface. The method is applied to the microcontroller unit, including: The detection circuit acquires the real-time grid voltage pulsation signal. The zero-crossing point of the voltage at the three-phase AC power input interface is identified based on the grid voltage pulsation signal. At the zero-crossing point of the voltage, the relay switch is controlled to perform a conduction or disconnection operation to switch the three-phase AC input power supply terminal to a single-phase AC input power supply state, so that the DC bus voltage output by the rectifier and filter circuit presents a periodic pulsating waveform, and when the DC bus voltage drops to the preset zero voltage threshold range, the insulated gate bipolar transistor in the inverter circuit is controlled to start working to complete the soft start process. After the induction cooker with full-zone heating completes its soft start, the corresponding power control mode is selected according to the target output power; the power control modes include low-power intermittent working mode, multi-coil coordinated power adjustment mode and high-power full-voltage power supply mode; The relay switch and the inverter circuit are controlled according to the selected power control mode so that the resonant load network outputs heating power that matches the target output power.

2. The zero-voltage start-up and multi-mode control method for a full-area heating induction cooker according to claim 1, characterized in that, The step of selecting the corresponding power control mode based on the target output power includes: The target output power is compared with a preset power threshold. Specifically, when the target output power is less than the power threshold, a low power gap working mode is selected; When the zero-voltage start-up of the full-area heating induction cooker and the simultaneous operation of multiple heating zones of the multi-mode control device, and when the target output power is greater than or equal to the power threshold, the multi-coil coordinated power adjustment mode is selected. When the target output power is greater than or equal to the power threshold and a single heating zone operates independently, the high-power full-voltage power supply mode is selected.

3. The zero-voltage start-up and multi-mode control method for a full-area heating induction cooker according to claim 1, characterized in that, When the low-power gap operating mode is selected, the following steps are performed: The relay switch is controlled to remain in the open state to maintain the pulsating characteristics of the DC bus voltage; The time interval between two adjacent zero-crossing points of the voltage is used as the reference for the gap working cycle. Within the specified gap working cycle reference, it is determined whether the DC bus voltage has dropped to a preset zero voltage threshold range based on the current amplitude of the DC bus voltage. When the DC bus voltage drops to the zero voltage threshold range, the time corresponding to the DC bus voltage dropping to the zero voltage threshold range is determined as the start-up time, and the insulated gate bipolar transistor is controlled to start working at the start-up time; Calculate the single working time and single interval time based on the target output power; Starting from the start time, the insulated gate bipolar transistor is controlled to work continuously according to the single working duration, and after the continuous working time reaches the single working duration, the insulated gate bipolar transistor is controlled to stop working. Starting from the moment when the insulated gate bipolar transistor (IGBT) stops working, the IGBT is controlled to remain in a stopped state according to the single gap duration. After the duration of maintaining the stopped state reaches the single gap duration, the process returns to the step of determining the start time as the moment when the DC bus voltage drops to the zero voltage threshold range. This process controls the IGBT to start and stop periodically.

4. The zero-voltage start-up and multi-mode control method for a full-area heating induction cooker according to claim 1, characterized in that, When the multi-coil coordinated power adjustment mode is selected, the following steps are performed: Obtain the material type information of the cookware placed on the heating coil corresponding to each heating zone; the material type information is determined based on the current value on the heating coil and the DC bus current value. Based on the material type information, the heating areas are grouped together, and the heating areas corresponding to cookware of the same material type are assigned to the same cookware group. Obtain a preset initial operating frequency, control the inverter circuit in each cookware group to synchronously reduce the frequency from the initial operating frequency, and obtain the real-time heating power of each heating zone in real time during the frequency reduction process; When the real-time heating power of each heating zone does not reach its corresponding preset power value, the step of controlling the inverter circuit in each pot group to synchronously reduce the frequency from the initial working frequency continues to be executed. When the real-time heating power of the first heating zone reaches the corresponding preset power value before the second heating zone, the operating frequency of the first heating zone is kept constant, and the current actual operating frequencies of the first and second heating zones are obtained. The operating frequency of the second heating zone continues to decrease. When the difference between the current actual operating frequency of the second heating zone and the operating frequency of the first heating zone reaches 1kHz, the inverter circuit corresponding to the first heating zone is controlled to continue to reduce its frequency to the actual operating frequency while maintaining the 1kHz operating frequency difference with the inverter circuit corresponding to the second heating zone. At the same time, the duty cycle of the drive signal of the inverter circuit corresponding to the first heating zone is reduced so that the real-time heating power of the first heating zone is maintained at the preset power value.

5. The zero-voltage start-up and multi-mode control method for a full-area heating induction cooker according to claim 4, characterized in that, The process of controlling the inverter circuits within each cookware group to synchronously reduce their frequency from the initial operating frequency also includes: Obtain the actual operating frequency of the inverter circuit corresponding to each heating zone; Calculate the actual operating frequency difference between any two heating zones that are operating simultaneously; Determine whether the actual operating frequency difference falls within the preset range of frequencies sensitive to human hearing; When the actual operating frequency difference falls within the range of frequencies sensitive to the human ear, the duty cycle of the drive signal of the inverter circuit corresponding to at least one of the heating areas is adjusted so that the actual operating frequency difference shifts out of the range of frequencies sensitive to the human ear.

6. The zero-voltage start-up and multi-mode control method for a full-area heating induction cooker according to claim 1, characterized in that, When the high-power full-voltage power supply mode is selected, the following steps are performed: The relay switch is kept in the engaged state so that the rectifier and filter circuit outputs the DC bus voltage at full voltage amplitude. Obtain the target sub-power corresponding to each heating zone; The operating frequency and drive signal duty cycle of the inverter circuit corresponding to each heating zone are controlled according to the power of each target sub-zone. The real-time heating power of each heating zone is acquired in real time, and it is determined whether each real-time heating power exceeds its corresponding target sub-power. When the real-time heating power of any of the heating areas exceeds the corresponding target sub-power, the operation of reducing the operating frequency is performed and the real-time heating power is acquired again. If the real-time heating power still exceeds the target sub-power after reducing the operating frequency, the operation of reducing the duty cycle of the drive signal is performed and the real-time heating power is acquired again. If the real-time heating power still exceeds the target sub-power after both the operation of reducing the operating frequency and the operation of reducing the duty cycle of the drive signal have been completed, then the relay switch is controlled to open, the operating frequency and the duty cycle of the drive signal are readjusted, and the real-time heating power is obtained again after readjustment. If the real-time heating power after readjustment still exceeds the target sub-power, then based on the current operating frequency and the current drive signal duty cycle, the system switches to the low-power gap operating mode.

7. The zero-voltage start-up and multi-mode control method for a full-area heating induction cooker according to claim 1, characterized in that, The method further includes the following steps: During the soft start process and throughout the entire process of controlling the inverter circuit to operate according to the selected power control mode, the operating voltage phase signal and operating current phase signal of the inverter circuit are acquired in real time. Based on the working voltage phase signal and the working current phase signal, determine whether the turn-on time of the insulated gate bipolar transistor is in a zero voltage state, and obtain the determination result; If the determination result indicates that the insulated gate bipolar transistor is not in a zero-voltage state when it is turned on, the output timing of the drive signal of the inverter circuit is adjusted until the insulated gate bipolar transistor is turned on in a zero-voltage state.

8. The zero-voltage start-up and multi-mode control method for a full-area heating induction cooker according to claim 1, characterized in that, Controlling the relay switch to perform an on or off operation at the voltage zero-crossing point so that the DC bus voltage output by the rectifier and filter circuit exhibits a periodic pulsating waveform, specifically including: The relay switch is controlled to perform a switching on or off once at the zero-crossing point of the voltage at least every two power frequency cycles, so that one phase voltage line of the AC input power supply is connected or disconnected in each switching cycle, and the DC bus voltage pulsating waveform is formed at the output of the rectifier and filter circuit; the switching cycle is at least two power frequency cycles. Wherein, the time interval between two adjacent conduction switching operations is greater than the inherent operating time of the relay switch, and the time interval between two adjacent disconnection switching operations is greater than the inherent operating time of the relay switch; the inherent operating time is the length of time required for the relay switch to complete the switching of the contact state from receiving the switching command.

9. A zero-voltage start and multi-mode control device for a full-area heating induction cooker, characterized in that, The device includes: Three-phase AC power input interface, used for connecting a three-phase AC power source; An AC switching circuit is connected to the output terminal of the three-phase AC power input interface. The AC switching circuit includes a main circuit relay, which is set on one phase voltage line of the three-phase AC power input interface. The main circuit relay is used to controllably connect or disconnect the one phase voltage line at the zero-crossing point of the voltage, so as to switch the three-phase AC input interface to a single-phase AC power input state. A rectifier and filter circuit is connected to the output terminal of the AC switching circuit. The rectifier and filter circuit is used to convert the AC power output by the AC switching circuit into DC power and perform filtering to output DC bus voltage. The detection circuit is connected to the three-phase AC power input interface and the output terminal of the rectifier filter circuit, respectively. The detection circuit is used to collect the grid voltage pulsation signal and the voltage and current parameters of the DC bus voltage. An inverter circuit is connected to the output terminal of the rectifier filter circuit. The inverter circuit includes multiple inverter units, each of which includes an upper bridge arm insulated gate bipolar transistor and a lower bridge arm insulated gate bipolar transistor. Each inverter unit is used to convert the DC bus voltage into high-frequency AC power according to the drive signal. A resonant load network is connected to the output terminal of the inverter circuit. The resonant load network includes multiple induction heating coils, each of which is connected to a corresponding inverter unit. Each induction heating coil is used to convert the high-frequency alternating current into an alternating magnetic field to heat the cookware placed on the induction heating coil. The microcontroller unit is connected to the AC switching circuit, the detection circuit, and the inverter circuit respectively. The microcontroller unit is used to receive the grid voltage pulsation signal, the voltage parameters, and the current parameters collected by the detection circuit, and to identify the voltage zero-crossing point based on the grid voltage pulsation signal. At the voltage zero-crossing point, the microcontroller unit outputs a first control signal to the AC switching circuit to control the conduction or disconnection of the main circuit relay, and outputs a second control signal to the inverter circuit to control the operating frequency and drive signal duty cycle of the insulated gate bipolar transistor in each inverter unit.

10. The zero-voltage start and multi-mode control device for a full-area heating induction cooker according to claim 9, characterized in that, Each inverter unit of the inverter circuit and each induction heating coil of the resonant load network are independently connected in a one-to-one correspondence. Each induction heating coil is independently connected to the output terminal of its corresponding inverter unit. The microcontroller unit independently outputs its corresponding second control signal to each inverter unit to achieve independent control of the heating power of each induction heating coil.

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