Resonance self-heating circuit control method and device and resonance self-heating circuit

Abstract

The invention discloses a resonance self-heating circuit control method and device and a resonance self-heating circuit, and the method comprises the steps: detecting a voltage zero crossing point when the resonance self-heating circuit works in a resonance manner at a current working frequency, generating a hardware interrupt signal when the voltage zero crossing point is detected, and carrying out the control of the resonance self-heating circuit according to the hardware interrupt signal; a switch tube in the resonance self-heating circuit is switched on, meanwhile, the switch-on time of the switch tube is calculated according to sampling data obtained through data sampling after the voltage zero crossing point is detected last time, the switch tube is switched off after the switch tube is switched on for a preset time, and the resonance self-heating circuit continues to perform resonance work; according to the method, the problem that the fixed turn-off time is not matched with the resonance period is solved by dynamically adjusting the turn-off time of the switching tube, so that the consistency of the resonance frequency is ensured, and the resonance self-heating circuit is enabled to efficiently and stably oscillate.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, and in particular to a resonant self-heating circuit control method, device, and resonant self-heating circuit. Background Technology

[0002] Currently, LC (Inductor-Capacitor) resonant heating technology has been widely used for self-heating of lithium batteries in low-temperature environments. However, LC resonant heating technology mainly includes traditional LC resonant heating, continuous sampling control, and open-loop control strategies. It uses fixed-frequency pulse width modulation (PWM) drive and lacks dynamic frequency or dynamic pulse width adjustment. When the battery's internal resistance changes due to temperature or state of charge, resonance mismatch is prone to occur, which reduces the heating efficiency of the LC resonant self-heating circuit. Summary of the Invention

[0003] To address the aforementioned technical problems, embodiments of the present invention provide a resonant self-heating circuit control method, apparatus, and resonant self-heating circuit, thereby solving the technical problem in existing resonant self-heating circuit control methods that, due to the inability to perform dynamic pulse width adjustment, are prone to resonant mismatch and reduced heating efficiency.

[0004] A first aspect of the present invention provides a method for controlling a resonant self-heating circuit, the method comprising: Obtain the current operating frequency of the resonant self-heating circuit when it self-heats the battery; The zero-crossing point of the voltage when the resonant self-heating circuit is operating at the current operating frequency is detected, and a hardware interrupt signal is generated when the zero-crossing point is detected. Based on the hardware interrupt signal, the switching transistor in the resonant self-heating circuit is turned on; After the switching transistor is turned on for a preset time, the switching transistor is turned off, allowing the resonant self-heating circuit to continue resonant operation. The preset time is determined by the sampling data obtained after the voltage zero-crossing point was detected last time.

[0005] One possible implementation of the first aspect also includes: Adjust the current operating frequency by following these steps: The preset resonant frequency is obtained based on the parameters of each component of the resonant self-heating circuit; Obtain the time interval between two consecutive voltage zero-crossing points when the resonant self-heating circuit is operating at the current operating frequency, and obtain the actual resonant frequency based on the time interval; Calculate the deviation between the actual resonant frequency and the preset resonant frequency. If the deviation is greater than the preset deviation threshold, decrease the current operating frequency. If the deviation is less than the preset deviation threshold, increase the current operating frequency.

[0006] In one possible implementation of the first aspect, the preset time is determined by the sampled data obtained after the last detection of a voltage zero crossing, including: Acquire the sampled data obtained after the last detection of a voltage zero crossing; The sampled data is extracted to obtain the current data; The actual effective value of the current is calculated based on the current data. The actual effective value of the current and the target effective value of the current are input into the PID controller for processing to obtain the preset time.

[0007] In one possible implementation of the first aspect, the sampled data obtained after the last detection of a voltage zero-crossing point includes: Based on the hardware interrupt signal, the timer is triggered to start and a timing trigger signal is generated; Based on a timed trigger signal, a multi-channel data conversion is performed using an analog-to-digital converter to obtain sampled data; The sampled data is sent to the memory area. Data conversion stops when the memory area is full of sampled data within a preset sampling period. Data conversion resumes when the next voltage zero crossing is detected.

[0008] In one possible implementation of the first aspect, the preset sampling period includes multiple timer periods, the timer periods being determined based on the preset sampling period and the number of channels.

[0009] In one possible implementation of the first aspect, the preset sampling period is less than the time interval between two consecutive adjacent voltage zero crossings, wherein the time interval between two consecutive voltage zero crossings is determined by the final operating frequency of the resonant self-heating circuit.

[0010] To address the same technical problem, a second aspect of the present invention provides a resonant self-heating circuit control device, comprising: The acquisition module is used to acquire the current operating frequency of the resonant self-heating circuit when it self-heats the battery. The detection module is used to detect the voltage zero-crossing point when the resonant self-heating circuit is operating at the current operating frequency. When the voltage zero-crossing point is detected, a hardware interrupt signal is generated. The conduction module is used to turn on the switching transistor in the resonant self-heating circuit according to the hardware interrupt signal; The disconnect module is used to disconnect the switching transistor after a preset time of conduction, so that the resonant self-heating circuit can continue to resonate. The preset time is determined by the sampling data obtained after the last detection of the voltage zero crossing.

[0011] One possible implementation of the second aspect also includes: The preset resonant frequency determination module is used to obtain the preset resonant frequency based on the parameters of each component of the resonant self-heating circuit. The time interval acquisition module is used to acquire the time interval between two consecutive voltage zero crossings when the resonant self-heating circuit is operating at the current operating frequency. The actual resonant frequency determination module is used to obtain the actual resonant frequency based on the time interval. The adjustment module is used to calculate the deviation between the actual resonant frequency and the preset resonant frequency. If the deviation is greater than the preset deviation threshold, the current operating frequency is reduced; if the deviation is less than the preset deviation threshold, the current operating frequency is increased.

[0012] In one possible implementation of the second aspect, the disconnection module includes a sampling data acquisition unit, an extraction unit, and a preset time calculation unit, wherein, The sampling data acquisition unit is used to acquire the sampling data obtained after the last detection of the voltage zero crossing. The extraction unit is used to extract the sampled data to obtain the current data; The preset time calculation unit is used to calculate the actual effective value of the current based on the current data, and input the actual effective value of the current and the target effective value of the current into the PID controller for processing to obtain the preset time.

[0013] A third aspect of the present invention provides a resonant self-heating circuit for executing the resonant self-heating circuit control method of the first aspect, comprising at least an LC resonant unit, a switching control circuit, and a sampling resistor, wherein... The first end of the LC resonant unit is connected to the positive terminal of the battery pack, and the second end of the LC resonant unit is connected to the first end of the switch control circuit. The second end of the switch control circuit is connected to the negative terminal of the battery pack through the sampling resistor.

[0014] The technical solution of this invention has the following advantages: The resonant self-heating circuit control method provided in this invention detects the voltage zero-crossing point of the resonant self-heating circuit when it resonates at the current operating frequency. When the voltage zero-crossing point is detected, a hardware interrupt signal is generated. Based on the hardware interrupt signal, the switching transistor in the resonant self-heating circuit is turned on. At the same time, the on-time of the switching transistor is calculated using the sampling data obtained after the previous detection of the voltage zero-crossing point. After the switching transistor has been turned on for a preset time, it is turned off, allowing the resonant self-heating circuit to continue resonant operation. The above method solves the problem of mismatch between the fixed off-time and the resonant period by dynamically adjusting the off-time of the switching transistor, thereby ensuring the consistency of the resonant frequency and enabling the resonant self-heating circuit to oscillate efficiently and stably. Attached Figure Description

[0015] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is a control flowchart of the resonant self-heating circuit control method in an embodiment of the present invention; Figure 2 This is a schematic diagram of the resonance control method of the resonant self-heating circuit control method in an embodiment of the present invention; Figure 3 This is a schematic diagram of the intermittent synchronous periodic sampling method of the resonant self-heating circuit control method in an embodiment of the present invention; Figure 4 This is a schematic diagram of the dynamic loop control of the resonant self-heating circuit control method in an embodiment of the present invention; Figure 5 This is a block diagram of the resonant self-heating circuit control device in an embodiment of the present invention; Figure 6 This embodiment provides a schematic diagram of a resonant self-heating circuit. Detailed Implementation

[0017] 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] The resonant self-heating circuit control method provided in this embodiment of the invention, such as... Figure 1 As shown, Figure 1 The flowchart of the resonant self-heating circuit control method includes steps S101 to S104, and the specific steps are as follows: S101. Obtain the current operating frequency of the resonant self-heating circuit when it self-heats the battery.

[0019] The resonant self-heating circuit in this embodiment refers to self-heating applied to lithium batteries in low-temperature environments. Its basic principle is to utilize the resonant characteristics of inductors and capacitors to generate Joule heat inside the battery through high-frequency alternating current, thereby achieving rapid temperature rise. It is also known as an LC resonant self-heating circuit. For example, the resonant self-heating circuit mainly consists of an LC resonant unit, a switching transistor, and a sampling resistor. Other components can be added as needed to enhance its functionality. The LC resonant unit, composed of inductors and capacitors, generates high-frequency alternating current through periodic charging and discharging, thus achieving rapid heating of the battery pack. The current operating frequency refers to the input frequency of the resonant self-heating circuit during rapid heating of the battery pack. However, the actual resonant frequency of the resonant self-heating circuit will drift with changes in operating conditions. Therefore, it is necessary to adjust the current operating frequency of the resonant self-heating circuit in real time to ensure that its actual resonant frequency accurately matches the preset resonant frequency.

[0020] The resonant self-heating circuit control method is used to control the resonant self-heating circuit. This control method is implemented through a resonant self-heating control device, which includes a resonant control unit, a high-frequency signal sampling unit, a loop control unit, and a fault detection unit. The resonant control unit mainly consists of a pulse-width modulation (PWM) generator, which precisely controls the resonant frequency and output power of the resonant self-heating circuit by adjusting the frequency and duty cycle of the PWM signal. The high-frequency signal sampling circuit includes a current sampling module and a voltage sampling module. The voltage sampling module acquires the high-frequency AC voltage signal across the resonant self-heating circuit in real time through a high-precision voltage transformer or a voltage divider resistor network. The current sampling module acquires the operating current of the resonant self-heating circuit through a series sampling resistor or a Hall current sensor, providing data support for power calculation and overcurrent protection. The loop control circuit uses the voltage and current data acquired by the high-frequency signal sampling section to perform proportional-integral-derivative (PID) circuit analysis. The Derivative Processing (PID) control algorithm dynamically adjusts the output parameters of the resonant control unit, i.e., the operating frequency of the resonant self-heating circuit. The fault detection circuit monitors the voltage, current, device temperature, and resonant frequency offset in the circuit in real time. When an abnormal operating condition is detected, it immediately triggers a fault protection mechanism, stopping heating by cutting off the switching transistor drive signal and shutting off the power input, thus preventing damage to circuit components or safety risks to the battery pack caused by abnormal heating. The resonant self-heating circuit control method proposed in this embodiment is applicable to various types of resonant self-heating circuits.

[0021] S102. Detect the voltage zero-crossing point when the resonant self-heating circuit is operating at the current operating frequency. When the voltage zero-crossing point is detected, generate a hardware interrupt signal.

[0022] In this embodiment, when the resonant self-heating circuit operates at the current working frequency, its voltage zero-crossing point is detected. The hardware interrupt signal is generated when the voltage zero-crossing point of the resonant self-heating circuit is detected. Because the resonant self-heating circuit exhibits purely resistive characteristics during resonant operation, i.e., the voltage and current have a 90° phase difference, a voltage zero-crossing point occurs. For each sine wave cycle output (e.g., 50kHz corresponds to a 20μs cycle), two zero-crossing points are generated, triggering two hardware interrupts. Specifically, when the resonant self-heating circuit begins to resonate under high-frequency AC excitation, forming a stable sinusoidal voltage / current with a fixed operating frequency, such as 50kHz~500kHz, the circuit approaches the resonant state. At this time, the comparator in the circuit captures the voltage zero-crossing point. After the voltage comparator captures the phase characteristics of the voltage zero-crossing point, it converts the phase characteristics of the zero-crossing point into the rising edge characteristics of a square wave. When the rising edge of the square wave output by the comparator reaches the external interrupt pin of the MCU (Microcontroller Unit) in the resonant self-heating control device, the MCU pin detects the level change, triggering the hardware response of the internal interrupt controller and generating a hardware interrupt signal.

[0023] In one embodiment, it further includes: Adjust the current operating frequency by following these steps: The preset resonant frequency is obtained based on the parameters of each component of the resonant self-heating circuit; Obtain the time interval between two consecutive voltage zero-crossing points when the resonant self-heating circuit is operating at the current operating frequency; The actual resonant frequency is obtained based on the time interval; Calculate the deviation between the actual resonant frequency and the preset resonant frequency. If the deviation is greater than the preset deviation threshold, decrease the current operating frequency. If the deviation is less than the preset deviation threshold, increase the current operating frequency.

[0024] In this embodiment, the current operating frequency of the resonant self-heating circuit needs to be dynamically adjusted, such as... Figure 2 As shown, based on the parameters of each component in the resonant self-heating circuit, the preset resonant frequency is obtained. For example, the preset resonant frequency is calculated using the LC resonant frequency formula based on the inductance and capacitance values ​​in the resonant self-heating circuit. With an inductance value of 10μH and a capacitance value of 25nF, the preset resonant frequency is calculated to be 318.3kHz according to the LC resonant frequency formula. The LC resonant frequency formula is: In the formula, Indicates the inductance value. This indicates the capacitance value.

[0025] When the resonant self-heating circuit operates at resonance, its actual resonant frequency will deviate from the preset resonant frequency due to various factors such as environmental interference. For example, an increase in temperature will cause the inductance value to decrease, thus increasing the resonant frequency; changes in load coupling will cause changes in the equivalent inductance value, resulting in a shift in the resonant frequency. Therefore, by detecting the voltage zero-crossing point in each charge-discharge cycle, the operating frequency of the resonant self-heating circuit is adjusted to accurately match the preset resonant frequency. Specifically, when the first voltage zero-crossing point (rising edge) is captured, a hardware interrupt is triggered, and a timer starts counting. When the next adjacent voltage zero-crossing point (falling edge) is detected, another interrupt is triggered, stopping the timer, reading the timer count value, calculating the time interval between two consecutive adjacent zero-crossing points, and adjusting the actual resonant frequency based on the time interval. For example, if the time interval between two consecutive voltage zero-crossings is 15μs, then since the time interval between two consecutive adjacent voltage zero-crossings is half a resonant cycle, the calculated actual resonant frequency is 314.43kHz. Subtracting the preset resonant frequency from the actual resonant frequency yields the deviation value. This deviation value is then used to adjust the current operating frequency. If the deviation value is greater than the preset deviation threshold, the current operating frequency is decreased; if the deviation value is less than the preset deviation threshold, the current operating frequency is increased. For example, 314.3kHz - 318.3kHz = -4kHz. If the deviation value is less than 0, the current operating frequency needs to be increased; conversely, if it is less than 0, the current operating frequency needs to be decreased. The adjustment amount for the current operating frequency can use a proportional adjustment strategy. For example, setting the adjustment coefficient to 0.8, the adjustment amount calculated based on the deviation value is 4kHz × 0.8 = 3.2kHz. If it is necessary to increase the current operating frequency, an adjustment amount is added to the current operating frequency to obtain the adjusted current operating frequency. If it is necessary to increase the current operating frequency, the adjustment amount is subtracted from the current operating frequency. Through the dynamic adjustment method proposed in this embodiment, the inherent resonant frequency can be accurately matched, realizing efficient energy transmission of the resonant self-heating circuit and ensuring oscillation stability.

[0026] S103. Based on the hardware interrupt signal, turn on the switching transistor in the resonant self-heating circuit.

[0027] In this embodiment, when the voltage zero-crossing point of the resonant self-heating circuit is detected, the switching transistor in the resonant self-heating circuit, namely the MOS (Metal-Oxide-Semiconductor Field-Effect Transistor), is simultaneously turned on, thereby enabling the battery pack to charge the resonant self-heating circuit, thus replenishing the oscillation energy of the LC resonant circuit and maintaining efficient resonant heating.

[0028] S104. After the switching transistor has been turned on for a preset time, the switching transistor is turned off, so that the resonant self-heating circuit continues to resonate. The preset time is determined by the sampling data obtained after the voltage zero-crossing point was detected last time.

[0029] In this embodiment, after the MOSFET has been turned on for a preset time, it is turned off, allowing the resonant self-heating circuit to oscillate automatically. The MOSFET is turned off dynamically, specifically by using the current data collected by the ADC module after the last hardware interrupt signal to calculate the preset on time of the MOSFET.

[0030] In one embodiment, the preset time is determined by the sampling data obtained after the last detection of a voltage zero crossing, including: Acquire the sampled data obtained after the last detection of a voltage zero crossing; The sampled data is extracted to obtain the current data; The actual effective value of the current is calculated based on the current data. The actual effective value of the current and the target effective value of the current are input into the PID controller for processing to obtain the preset time.

[0031] In this embodiment, the preset conduction time of the MOSFET is determined based on the sampling data collected after the last hardware interrupt signal was generated. Specifically, for example... Figure 3 As shown, Figure 3This is an intermittent synchronous periodic sampling method. Each time a hardware interrupt signal is generated, a timer is simultaneously triggered. After the timer starts, it sends a timing trigger signal to the ADC module. The ADC module then begins data conversion, converting the data collected by the current or voltage sampling module. Once the conversion is complete, the converted data is stored in the DMA (Direct Memory Access Memory Region) memory area. Conversion stops when the DMA memory area stores data for a preset sampling period, waiting for the next zero-crossing detection before resuming data conversion. The data stored in the DMA memory area includes, but is not limited to, voltage, current, and temperature data. While waiting for the next zero-crossing, the actual effective current value is calculated using the existing current data in the DMA. The deviation between the actual effective current value and the target effective current value is then calculated, and this deviation value is input to the PID controller for processing, resulting in the PWM drive pulse width. The PWM drive pulse width refers to the duration of the PWM signal's high level. Therefore, the preset time can be determined based on the drive pulse width. When the hardware interrupt signal is generated at the next zero-crossing, the MOSFET is turned on for a preset time and then turned off. By setting a dynamic time to turn off the MOSFET, the current is ensured to approach the ideal value, and the output is stable.

[0032] It should be noted that the data conversion performed by the ADC module is a step in the data sampling process. After the sensor or sampling resistor obtains the instantaneous voltage or current value in the circuit, it sends the instantaneous voltage or current value to the ADC module for data conversion, converting the instantaneous value into a digital signal, and then storing the converted digital signal in the DMA.

[0033] In one embodiment, the sampling data obtained after the last detection of a voltage zero crossing includes: Based on the hardware interrupt signal, the timer is triggered to start and a timing trigger signal is generated; Based on a timed trigger signal, a multi-channel data conversion is performed using an analog-to-digital converter to obtain sampled data; The sampled data is sent to the memory area. Data conversion stops when the memory area is full of sampled data within a preset sampling period. Data conversion resumes when the next voltage zero crossing is detected.

[0034] In this embodiment, upon the generation of a hardware interrupt signal, a timer is triggered to start counting according to a preset period. Once the count reaches its upper limit, a trigger pulse (timed trigger signal) is generated. This trigger pulse is sent directly to the ADC (Analog-to-Digital Converter) module via the MCU's internal hardware link. The ADC module immediately initiates conversion across multiple channels, completing multi-channel cyclic data conversion according to a preset sampling period. After the ADC module completes data conversion for one timer cycle, it triggers automatic DMA transfer. The DMA module stores the converted data in a memory area capable of storing at least one complete preset sampling period. When the DMA is full, the timer stops, marking the end of one complete preset sampling period of data conversion. Then, the data processing stage begins. Based on the acquired data, peak current, peak voltage, RMS current, and frequency are calculated. These calculated data are transmitted to the host computer via RTT (Real-Time Transmission). The system then waits for the next zero-crossing trigger interrupt signal to allow the ADC module to continue data conversion. By incorporating time-consuming operations such as data processing and data transmission into the data sampling cycle, the sampling frequency is reduced, thereby lowering the data processing power and communication bandwidth requirements of the MCU. Data from one cycle is processed within multiple resonant cycles, while data from the remaining cycles is discarded. Because the same zero-crossing interrupt is used with the LC resonant control section, strict synchronization between sampling and the resonant cycle is ensured, and the integrity of the cycle is guaranteed.

[0035] In one embodiment, the preset sampling period is determined by the maximum sampling frequency of the analog-to-digital converter.

[0036] In this embodiment, the preset sampling period is determined by the maximum sampling frequency of the analog-to-digital converter (ADC). For example, if the maximum sampling frequency of the ADC module is 4.5MHz, then the maximum sampling period is 1 / 4.5MHz. The corresponding preset sampling period can be set according to actual needs. If data from three channels needs to be acquired, then the frequency allocated to each channel is 1.5MHz, and the sampling period for each channel is 1 / 1.5MHz. Therefore, the sampling period for each channel needs to be greater than or equal to 1 / 1.5MHz to ensure that the acquisition of data from all three channels is completed within the preset sampling period.

[0037] In one embodiment, the preset sampling period is less than the time interval between two consecutive adjacent voltage zero crossings, wherein the time interval between two consecutive voltage zero crossings is determined by the final operating frequency of the resonant self-heating circuit.

[0038] In this embodiment, the preset sampling period is less than the time interval between two consecutive adjacent voltage zero crossings. The time interval between two consecutive adjacent voltage zero crossings is half a resonance period. One resonance period is determined by the final operating frequency of the resonant self-heating circuit. For example, if the final operating frequency of the resonant self-heating circuit is 317.5kHz, then by calculating the derivative of the final operating frequency, the resonance period is 3.15μs. The time interval between two consecutive voltage zero crossings is then calculated to be half of the resonance period, i.e., 1.75μs.

[0039] The resonant self-heating circuit control device provided in this embodiment of the invention, such as... Figure 5 As shown, Figure 5 A block diagram of the resonant self-heating circuit control device 500, including: The acquisition module 501 is used to acquire the current operating frequency of the resonant self-heating circuit when it self-heats the battery. The detection module 502 is used to detect the voltage zero-crossing point when the resonant self-heating circuit is working at the current operating frequency. When the voltage zero-crossing point is detected, a hardware interrupt signal is generated. The conduction module 503 is used to turn on the switching transistor in the resonant self-heating circuit according to the hardware interrupt signal; The disconnect module 504 is used to disconnect the switching transistor after a preset time of conduction, so that the resonant self-heating circuit can continue to resonate. The preset time is determined by the sampling data obtained after the last detection of the voltage zero crossing.

[0040] In one embodiment, it further includes: The preset resonant frequency determination module is used to obtain the preset resonant frequency based on the parameters of each component of the resonant self-heating circuit. The time interval acquisition module is used to acquire the time interval between two consecutive voltage zero crossings when the resonant self-heating circuit is operating at the current operating frequency. The actual resonant frequency determination module is used to obtain the actual resonant frequency based on the time interval. The adjustment module is used to calculate the deviation between the actual resonant frequency and the preset resonant frequency. If the deviation is greater than the preset deviation threshold, the current operating frequency is reduced; if the deviation is less than the preset deviation threshold, the current operating frequency is increased.

[0041] In one embodiment, the disconnection module includes a sampling data acquisition unit, an extraction unit, and a preset time calculation unit, wherein, The sampling data acquisition unit is used to acquire the sampling data obtained after the last detection of the voltage zero crossing. The extraction unit is used to extract the sampled data to obtain the current data; The preset time calculation unit is used to calculate the actual effective value of the current based on the current data, and input the actual effective value of the current and the target effective value of the current into the PID controller for processing to obtain the preset time.

[0042] The specific implementation of the control device for the resonant self-heating circuit is basically the same as the specific embodiment of the control method for the resonant self-heating circuit described above, and will not be repeated here.

[0043] The resonant self-heating circuit provided in this embodiment of the invention is used to execute the resonant self-heating circuit control method described in this embodiment, and includes at least an LC resonant unit, a switching control circuit, and a sampling resistor, wherein... The first end of the LC resonant unit is connected to the positive terminal of the battery pack, and the second end of the LC resonant unit is connected to the first end of the switch control circuit. The second end of the switch control circuit is connected to the negative terminal of the battery pack through the sampling resistor.

[0044] Figure 6 This embodiment provides a schematic diagram of a resonant self-heating circuit. The resonant self-heating circuit includes at least an LC resonant unit, a switching control circuit, and a sampling resistor. The first terminal of the LC resonant unit is connected to the positive terminal of the battery pack, and the second terminal of the LC resonant unit is connected to the first terminal of the switching control circuit. The second terminal of the switching control circuit is connected to the negative terminal of the battery pack through the sampling resistor. Specifically, the LC resonant unit includes an inductor L1 and a capacitor C1. The switching control circuit includes a first switching transistor Q1 and a second switching transistor Q2. It also includes a MOSFET Q3, a sampling resistor R1, and a fuse F1. For specific limitations of the resonant self-heating circuit, please refer to the above-described limitations of the resonant self-heating circuit control method, which will not be repeated here. Those skilled in the art will recognize that the various modules and steps described in conjunction with the embodiments disclosed in this application can be implemented in hardware, software, or a combination of both. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0045] The present invention proposes a control method for a resonant self-heating circuit. After triggering a hardware interrupt signal by voltage zero crossing, intermittent multi-channel synchronous data sampling is performed. Then, the pulse width of the resonant self-heating circuit during resonant operation is dynamically adjusted based on the sampled data. This solves the efficiency loss caused by the mismatch between fixed off time and resonant period, while avoiding complex frequency modulation algorithms, and achieving the dual goals of adaptive resonance and current optimization.

[0046] 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.

[0047] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.

Claims

1. A method of controlling a resonant self-heating circuit, characterized by, The method comprises the following steps: acquiring a current working frequency of a resonant self-heating circuit when the resonant self-heating circuit self-heats a battery; detecting a voltage zero-crossing point of the resonant self-heating circuit when the resonant self-heating circuit works at the current working frequency, and generating a hardware interrupt signal after detecting the voltage zero-crossing point; turning on a switch tube in the resonant self-heating circuit according to the hardware interrupt signal; turning off the switch tube after a preset time when the switch tube is turned on, and making the resonant self-heating circuit continue to work in resonance, wherein the preset time is determined by sampling data obtained after detecting the voltage zero-crossing point last time.

2. The resonant self-heating circuit control method of claim 1, wherein, The method further comprises the following steps: adjusting the current working frequency by the following steps: obtaining a preset resonant frequency according to parameters of each element of the resonant self-heating circuit; acquiring a time interval between two continuous voltage zero-crossing points when the resonant self-heating circuit works at the current working frequency; obtaining an actual resonant frequency according to the time interval; calculating a deviation value of the actual resonant frequency and the preset resonant frequency, and lowering the current working frequency if the deviation value is greater than a preset deviation threshold, or raising the current working frequency if the deviation value is less than the preset deviation threshold.

3. The resonant self-heating circuit control method of claim 1, wherein, The preset time is determined by sampling data obtained after detecting the voltage zero-crossing point last time, comprising the following steps: obtaining sampling data obtained after detecting the voltage zero-crossing point last time; extracting the sampling data to obtain current data; calculating an actual current effective value according to the current data, inputting the actual current effective value and a target current effective value into a PID controller for processing to obtain the preset time.

4. The resonant self-heating circuit control method of claim 3, wherein, The step of obtaining the sampling data obtained after detecting the voltage zero-crossing point last time comprises the following steps: triggering a timer to start and generate a timing trigger signal according to the hardware interrupt signal; performing multi-channel data conversion by using an analog-to-digital converter based on the timing trigger signal to obtain the sampling data; sending the sampling data to a memory area, stopping data conversion when the memory area is at least full of sampling data in a preset sampling period, and continuing data conversion when detecting the next voltage zero-crossing point.

5. The resonant self-heating circuit control method of claim 4, wherein, The preset sampling period is determined by a maximum sampling frequency of the analog-to-digital converter.

6. The resonant self-heating circuit control method of claim 4, wherein, The preset sampling period is less than a time interval between two continuous adjacent voltage zero-crossing points, wherein the time interval between the two continuous voltage zero-crossing points is determined by a final working frequency of the resonant self-heating circuit.

7. A resonant self-heating circuit control device, characterized by comprising: The method comprises the following steps: an acquiring module, configured to acquire a current working frequency of a resonant self-heating circuit when the resonant self-heating circuit self-heats a battery; a detecting module, configured to detect a voltage zero-crossing point of the resonant self-heating circuit when the resonant self-heating circuit works at the current working frequency, and generate a hardware interrupt signal after detecting the voltage zero-crossing point; a turning-on module, configured to turn on a switch tube in the resonant self-heating circuit according to the hardware interrupt signal; The disconnecting module is configured to disconnect the switch tube after the switch tube is turned on for a preset time, so that the resonant self-heating circuit continues to work in resonance, wherein the preset time is determined by the sampling data obtained by data sampling after the last detection of the voltage zero-crossing point.

8. The resonant self-heating circuit control device of claim 7, wherein, Further comprising: A preset resonant frequency determining module configured to obtain a preset resonant frequency according to parameters of each element of the resonant self-heating circuit; A time interval obtaining module configured to obtain a time interval between two continuous voltage zero-crossing points when the resonant self-heating circuit works at the current working frequency; An actual resonant frequency determining module configured to obtain an actual resonant frequency according to the time interval; An adjusting module configured to calculate a deviation value of the actual resonant frequency and the preset resonant frequency, and reduce the current working frequency if the deviation value is greater than a preset deviation threshold, or increase the current working frequency if the deviation value is less than the preset deviation threshold.

9. The resonant self-heating circuit control device of claim 7, wherein, The disconnecting module comprises a sampling data obtaining unit, an extracting unit and a preset time calculating unit, wherein, The sampling data obtaining unit is configured to obtain sampling data obtained by data sampling after the last detection of the voltage zero-crossing point; The extracting unit is configured to extract the sampling data to obtain current data; The preset time calculating unit is configured to calculate an actual current effective value according to the current data, input the actual current effective value and a target current effective value into a PID controller for processing, and obtain the preset time.

10. A resonant self-heating circuit, characterized by The resonant self-heating circuit control method according to any one of claims 1 to 6 is executed by at least an LC resonant unit, a switch control circuit and a sampling resistor, wherein, A first end of the LC resonant unit is configured to be connected with a positive electrode of a battery pack, a second end of the LC resonant unit is connected with a first end of the switch control circuit, and a second end of the switch control circuit is configured to be connected with a negative electrode of the battery pack through the sampling resistor.

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