Control method of hybrid flyback topological converter and electronic equipment thereof

Abstract

The embodiment of the invention discloses a control method of a hybrid flyback topological converter and electronic equipment thereof. The method comprises the following steps: calculating the demagnetization time of a transformer; the demagnetization time is the time when the excitation current drops from the peak value to zero; calculating negative resonance time; the negative resonance time is the time when the excitation current is reduced from minus zero to a preset reference value; and obtaining the turn-on time of the low-end switching tube according to the demagnetization time and the negative resonance time. According to the embodiment of the invention, the switch-on time of the low-end switch tube is determined by calculating the demagnetization time of the transformer, namely the time when the excitation current drops from the peak value to zero, and the negative resonance time, namely the time when the excitation current drops from zero to the preset reference value, so that the switch-on time of the low-end switch tube is determined on the premise of not changing the original topological structure. According to the method, the power loss caused by adding an additional detection circuit is avoided, the problem of low precision of a traditional volt-second balance method is solved, the switching time sequence can be accurately controlled through real-time calculation and adjustment, and the efficiency and reliability of the system are effectively improved.

Description

Technical Field

[0001] Embodiments of the present invention relate to a field, and in particular, to a control method for a hybrid flyback topology converter and an electronic device thereof. Background Art

[0002] The hybrid flyback converter (Hybrid flyback converter or asymmetrical half-bridge fly-back converter) combines the performance of a traditional simplified flyback topology and a resonant converter. By controlling the high-voltage side and low-voltage side power switching devices (MOSFET, GaN, etc.) in the asymmetrical half-bridge flyback topology and adjusting the positive and negative magnetizing currents, zero-voltage switching can be achieved on the primary side of the transformer and zero-current switching can be achieved on the secondary side, significantly reducing energy loss and heat generation, thereby improving the efficiency of the system. In addition, the energy of the transformer leakage inductance is recycled, further improving the efficiency. With its wide operating range, ultra-high conversion efficiency and low standby power, the hybrid flyback converter has been widely used in USB PD power adapters.

[0003] Among them, the transformer excitation current can be controlled by peak current comparison. However, since the demagnetizing current or resonant current is generally not detected, controlling the turn-on time of the low-side switch is a difficult point, which will directly affect the efficiency and reliability of the system.

[0004] Currently, there are mainly the following two methods for controlling the turn-on time of the low-side switch: One is based on the volt-second balance principle of the inductor, but this method has low accuracy and is not easy to adjust; the other is to place a current detection resistor in the resonant loop to detect the resonant current. The defect of this method is that it increases the extra power loss generated by the resonant current passing through the detection resistor, and the design complexity of differential detection is also increased compared with single-ended detection. Summary of the Invention

[0005] The main technical problem to be solved by the embodiments of the present invention is to provide a control method for a hybrid flyback topology converter and an electronic device thereof, which can solve some problems existing in the control of the turn-on time of the low-side switch of the existing hybrid flyback topology converter.

[0006] To solve the above technical problem, a technical solution adopted by an embodiment of the present invention is: to provide a control method for a hybrid flyback topology converter, including: calculating the demagnetization time of the transformer; the demagnetization time is the time when the excitation current drops from the peak to zero; calculating the negative resonant time; the negative resonant time is the time when the excitation current drops from zero to a preset reference value; obtaining the turn-on time of the low-side switch according to the demagnetization time and the negative resonant time.

[0007] In some embodiments, calculating the demagnetization time of the computing transformer includes: obtaining the peak reference value of the peak current comparator; collecting the equivalent excitation inductance parameter of the transformer; detecting the voltage value applied to the excitation inductance; and calculating the demagnetization time based on the peak reference value, the equivalent excitation inductance parameter, and the voltage value.

[0008] In some embodiments, the peak reference value is calculated according to the following formula:

[0009] I MPEAK ·R S =V COMP ,

[0010] where V COMP is the compensation voltage, I MPEAK is the peak reference value, and R S is the detection resistor; the compensation voltage is the equivalent voltage obtained by transforming the secondary side voltage value of the transformer;

[0011] The demagnetization time is calculated according to the following formula:

[0012]

[0013] where T ON_LS1 is the demagnetization time, N·V OUT is the voltage value, and L M is the equivalent excitation inductance parameter.

[0014] In some embodiments, calculating the negative resonance time includes: setting a positive current reference value; detecting the excitation current during the turn-on of the high-side switch; comparing the excitation current with the positive current reference value to generate a pulse signal; and adjusting the negative resonance time according to the pulse signal.

[0015] In some embodiments, setting the positive current reference value includes: obtaining the noise reference value of the hybrid flyback topology converter; setting the positive current reference value, and the positive current reference value is greater than the noise reference value.

[0016] In some embodiments, generating the pulse signal includes: generating the pulse signal with the rising edge of the high-side switch as the trigger signal; terminating the pulse signal when the excitation current is greater than the positive current reference value; measuring the pulse width of the pulse signal; and comparing the pulse width with a preset threshold.

[0017] In some embodiments, adjusting the negative resonance time according to the pulse signal includes: initializing the negative resonance time; when the pulse width is less than the preset threshold, extending the negative resonance time by a preset adjustment step; when the pulse width is greater than the preset threshold, shortening the negative resonance time by the preset adjustment step; and when the pulse width is equal to the preset threshold, keeping the negative resonance time unchanged.

[0018] To solve the above technical problem, another technical solution adopted in the embodiments of the present invention is: providing an integrated circuit, including: a controller, where the controller is used to control a hybrid flyback topology converter and execute the control method of the hybrid flyback topology converter as described above.

[0019] To solve the above technical problem, another technical solution adopted in the embodiments of the present invention is: providing an electronic device, including: at least one processor; at least one network interface, where the network interface is communicatively connected to the corresponding processor; and a memory communicatively connected to the at least one processor; wherein, the network interface is used to establish a communication connection between the processor and other external devices; the memory stores instructions executable by the at least one processor, and when the instructions are executed by the at least one processor, the at least one processor is enabled to execute the control method of the hybrid flyback topology converter as described above.

[0020] To solve the above technical problem, another technical solution adopted in the embodiments of the present invention is: providing a non-volatile computer storage medium, where the computer storage medium stores computer-executable instructions, and when the computer-executable instructions are executed by one or more processors, the one or more processors can be enabled to execute the control method of the hybrid flyback topology converter as described above.

[0021] The beneficial effects of the embodiments of the present invention are: different from the prior art, the embodiments of the present invention determine the turn-on time of the low-side switch tube by calculating the demagnetization time of the transformer, that is, the time when the exciting current drops from the peak value to zero, and the negative resonance time, that is, the time when the exciting current drops from zero to a preset reference value. Without changing the original topology structure, it not only avoids the power loss caused by adding an additional detection circuit, but also overcomes the problem of low accuracy of the traditional volt-second balance method. Through real-time calculation and adjustment, it can accurately control the switching timing and effectively improve the system efficiency and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic structural diagram of a typical application circuit of a hybrid flyback topology converter;

[0023] Figure 2 is a schematic diagram of signal waveforms of a hybrid flyback topology converter in critical conduction mode;

[0024] Figure 3 It is a schematic flowchart of a control method for a hybrid flyback topology converter provided by an embodiment of the present invention;

[0025] Figure 4 It is a schematic flowchart of calculating the demagnetization time provided by an embodiment of the present invention;

[0026] Figure 5 It is a schematic diagram of the calculation principle of the demagnetization time;

[0027] Figure 6 It is a schematic flowchart of calculating the negative resonance time provided by an embodiment of the present invention;

[0028] Figure 7 It is a schematic diagram of the principle of generating a pulse signal;

[0029] Figure 8 It is a schematic flowchart of setting the positive current reference value provided by an embodiment of the present invention;

[0030] Figure 9 It is a schematic flowchart of generating a pulse signal provided by an embodiment of the present invention;

[0031] Figure 10 It is a schematic flowchart of adjusting the negative resonance time provided by an embodiment of the present invention;

[0032] Figure 11 It is a schematic diagram of the principle of adjusting the negative resonance time;

[0033] Figure 12 It is another schematic diagram of the principle of adjusting the negative resonance time;

[0034] Figure 13 It is a schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. Specific embodiments

[0035] For the convenience of understanding this application, the following will provide a more detailed description of this application in conjunction with the accompanying drawings and specific embodiments. It should be noted that when an element is described as "fixed to" another element, it can be directly on the other element, or there can be one or more intermediate elements therebetween. When an element is described as "connected to" another element, it can be directly connected to the other element, or there can be one or more intermediate elements therebetween. The terms "upper", "lower", "inner", "outer", "bottom", etc. used in this specification indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation to this application. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0036] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by those skilled in the technical field to which this application belongs. The terms used in this specification in the description of this application are only for the purpose of describing specific embodiments and are not used to limit this application. The term "and / or" used in this specification includes any and all combinations of one or more of the related listed items.

[0037] In addition, the technical features involved in different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0038] The following will describe the technical solutions in this application in conjunction with the accompanying drawings.

[0039] Refer to Figure 1 the shown typical hybrid flyback topology converter application circuit, which includes the primary and secondary circuits of the transformer. A high-side switch and a low-side switch are provided on the primary side of the transformer, and the positive and negative magnetizing currents are adjusted by controlling the conduction timing of the two switches. An auxiliary winding Laux and a current detection resistor Rs are also provided in the circuit, where the auxiliary winding is used to detect the zero crossing of the excitation current, and the current detection resistor is used to judge the peak value of the primary excitation current. The voltage closed-loop compensation is completed in cooperation with the USB PD controller on the secondary side of the transformer, and the compensation output is transmitted to the feedback pin of the primary controller through an optocoupler.

[0040] When the hybrid flyback topology converter is applied in a power adapter, it generally supports multi-mode operation. It operates in the Critical Conduction Mode (CrM) at high power, in the Discontinuous Conduction Mode (DCM) at medium power, and in the Burst mode at low power.

[0041] Figure 2 The signal waveforms of the hybrid flyback topology converter operating in the CrM mode are shown. From top to bottom, they are: the driver signal GH of the high-side switch, the driver signal GL of the low-side switch, and the primary current I of the transformer HB , the midpoint voltage V SW and the auxiliary winding voltage V AUX . When V SW reaches VIN, the driver signal GH of the high-side switch turns on, i.e., zero-voltage switching. When AHBCS (the voltage generated by the exciting current passing through the detection resistor when the high-side switch is turned on) reaches the positive current reference value I MAGpos value through the analog comparator, the driver signal GH of the high-side switch turns off, and the conduction time of the high-side switch is T ON_HS . After the programmable dead time between the turn-off of the driver signal GH of the high-side switch and the turn-on of the driver signal GL of the low-side switch, the driver signal GL of the low-side switch turns on. If the driver signal GL of the low-side switch turns off at the appropriate time, the resonance in the loop should push V SW close to VIN. And zero-voltage switching turn-on is achieved. If the turn-on time of the driver signal GL of the low-side switch is too short, there is not enough energy to drive V SW to VIN, and zero-voltage switching cannot be achieved. If the turn-on time of the driver signal GL of the low-side switch is too long, the magnetizing current is too negative, which will cause additional power loss. In short, the conduction time T ON_LS of the driver signal GL of the low-side switch must be accurately calculated to obtain the optimal effect. This is the difficulty of AHB control because in the actual circuit as Figure 1 shown, neither the primary demagnetizing current nor the secondary current is detected.

[0042] The current methods for controlling the conduction time T ON_LS of the low-side switch are mainly the following two: The first is to use the volt-second balance principle of the inductor. Specifically: in a switched-mode power supply operating in a steady state, the positive volt-second value across the inductor is equal to the negative volt-second value. The volt-second number is the product of the voltage V across the inductor and the switching operation time T. In a cycle T, the integral of the inductor voltage over time is 0. When the switched-mode power supply circuit is operating in a steady state, the change in the inductor current within one switching cycle is ultimately zero, that is, the increase in the current through the inductor when the switch is on is equal to the decrease in the inductor current when the switch is off. The volt-second principle can ensure that the inductor does not exhibit magnetic bias and does not saturate.

[0043] When AHB is in a stable operating state, the equivalent primary exciting inductor of the transformer also follows the volt-second balance principle. During the turn-on time T ON_HSAmong them, the voltage across its two ends is V IN -V CR , the inductor current is increasing. V CR is the voltage across the resonant capacitor, which is equal to N·V at steady state OUT , where N is the transformer turns ratio. Here, the leakage inductance and the voltage drop of the power transistor can be ignored. When the low-side switch is turned on, the voltage across the magnetizing inductor is -N·V OUT , the inductor current is decreasing. At other times, the voltage across the inductor is zero. According to the volt-second balance principle:

[0044] (V IN -N·V OUT )·T ON_HS -N·V OUT ·T ON_LS = 0,

[0045] the turn-on time T of the low-side switch can be obtained ON_LS . In actual implementation, the volt-second balance principle of the inductor is often simulated by converting the voltage into current and the inductor into a capacitor. The advantage of this method is simplicity, but the accuracy is limited and it is not easy to adjust.

[0046] The second method is to place the current sensing resistor in the resonant loop to detect the resonant current. The sensing resistor R CS is placed in the resonant loop, and the controller adds a differential sensing pin to detect the magnitude and polarity of the current. The sensing resistor R S is outside the resonant loop, and only a single-ended pin is required to detect the peak value of the current. When the demagnetizing current is negative, the resonant current coincides with the demagnetizing current, and the ideal turn-off moment of the low-side switch is when the current reaches the negative current reference value I MAGneg . Now the current is in the detection state, and it is only necessary to judge that the current is equal to the negative current reference value I MAGneg to turn off the low-side switch. This scheme simplifies the calculation of the turn-on time T ON_LS of the low-side switch, but the disadvantage is that it increases the additional power loss generated by the resonant current passing through the sensing resistor R CS . Moreover, compared with single-ended detection, the design complexity of differential detection has also increased a lot.

[0047] To solve the above problems, the present invention provides a control method for a hybrid flyback topology converter, and its flow schematic diagram is as Figure 3 shown, specifically including the following steps:

[0048] Step S100: Calculate the demagnetization time of the transformer.

[0049] During the operation of a hybrid flyback topology converter, the demagnetization time of the transformer characterizes the time required for the exciting current to drop from its maximum value to zero. By monitoring and analyzing the state of the exciting current and combining with the relevant characteristic parameters of the transformer, the demagnetization time can be obtained. When calculating the demagnetization time, the existing feedback parameters and detection circuits in the circuit are utilized, without adding additional detection units, thus avoiding the introduction of new power losses. When the hybrid flyback topology converter operates in the critical conduction mode, the demagnetization process of the transformer directly affects the system efficiency. Accurately calculating the demagnetization time is of great significance for optimizing the system performance. By reasonably utilizing the existing detection circuit, the accurate calculation of the demagnetization time can be achieved.

[0050] Step S200: Calculate the negative resonant time.

[0051] The negative resonant time describes the time period during which the exciting current drops from zero to a specific reference value. Since the resonant current is usually not detected, relevant information needs to be obtained indirectly. During the conduction period of the high-side switch, the change trend of the exciting current is monitored, a control signal is generated based on the set reference level, and the magnitude of the negative resonant time is determined through signal analysis. The negative resonant process involves the recycling of the energy of the transformer leakage inductance. Reasonably controlling the negative resonant time can significantly improve the energy conversion efficiency. During the calculation of the negative resonant time, by setting appropriate reference levels and signal analysis methods, the dynamic optimization of the negative resonant time can be achieved to ensure that the system always operates in the best state.

[0052] Step S300: Obtain the turn-on time of the low-side switch according to the demagnetization time and the negative resonant time.

[0053] The turn-on time of the low-side switch has an important impact on the operating efficiency and reliability of the hybrid flyback topology converter. By comprehensively considering the previously calculated demagnetization time and negative resonant time, a dynamic optimization method is adopted to determine the turn-on time. The determination of the turn-on time needs to comprehensively consider multiple factors such as the input voltage, output load, and transformer parameters, and the optimal system performance is achieved by establishing a reasonable control strategy.

[0054] In the embodiment of the present application, the turn-on time of the low-side switch is obtained according to the demagnetization time and the negative resonant time. The obtaining process is realized by adding the calculated demagnetization time and the negative resonant time. The demagnetization time reflects the time required for the exciting current to drop from the peak value to zero, and the negative resonant time characterizes the time required for the exciting current to drop from zero to the preset reference value. Adding the two time parameters gives the complete turn-on time of the low-side switch.

[0055] Through the above control method, the accurate control of the turn-on time of the low-end switch tube is achieved, enabling the hybrid flyback topology converter to achieve zero-voltage switching and zero-current switching, significantly reducing energy losses. In practical applications, this control method can adapt to different working conditions and load requirements, with strong robustness and adaptability. For the deviation of transformer parameters and external interference, this method also exhibits good anti-interference ability, ensuring the stable and reliable operation of the system.

[0056] Refer to Figure 4 and Figure 5 , the specific implementation method of calculating the demagnetization time in the control method of the hybrid flyback topology converter is supplemented and explained as follows:

[0057] Step S110: Obtain the peak reference value of the peak current comparator.

[0058] The peak reference value reflects the maximum amplitude of the transformer excitation current I MAG . By obtaining the relevant parameters of the compensation voltage V COMP and the detection resistor R S , the peak reference value is calculated. The compensation voltage is derived from the equivalent voltage obtained by transforming the secondary side voltage value of the transformer. According to the circuit characteristics, the peak reference value can be calculated by the formula I MPEAK ·R S = V COMP . This step provides a key parameter for the subsequent calculation of the demagnetization time, directly affecting the accuracy of the calculation result.

[0059] Step S120: Collect the equivalent excitation inductance parameters of the transformer.

[0060] The equivalent excitation inductance parameters reflect the magnetization characteristics of the transformer, and this parameter directly affects the change rate of the excitation current. The collection process makes full use of the existing circuit structure, without the need to add additional detection units, avoiding additional power losses. In practical applications, the equivalent excitation inductance parameters may change with the working conditions, so real-time collection is required to ensure the calculation accuracy.

[0061] Step S130: Detect the voltage value applied to the excitation inductance. During the demagnetization phase, the voltage value remains relatively stable, and this voltage value can be obtained through the existing voltage detection circuit. The voltage applied to both ends of the excitation inductance and the equivalent excitation inductance parameters jointly determine the change rate of the excitation current I MAG . The voltage detection requires sufficient sampling accuracy to ensure the reliability of the subsequent calculation results.

[0062] Step S140: Calculate the demagnetization time based on the peak reference value, equivalent excitation inductance parameters, and voltage value. Using the formula

[0063]

[0064] Perform calculations, where T ON_LS1 represents the demagnetization time, and L M represents the equivalent excitation inductance parameter, and I MPEAK represents the peak reference value, N·V OUT represents the voltage value applied to the excitation inductance. This calculation formula is derived based on the basic characteristics of the excitation inductance and can accurately reflect the time characteristics of the demagnetization process. When the working conditions change, by updating the parameters in real time, the calculation result of the demagnetization time can be dynamically adjusted.

[0065] Through the above implementation manner, the accurate calculation of the demagnetization time of the transformer is realized. This method makes full use of the existing circuit structure, without adding additional detection circuits, and avoids the power loss problem caused thereby. In practical applications, this method exhibits good adaptability and anti-interference ability. By obtaining the circuit parameters in real time, the demagnetization time can be dynamically calculated, enabling the control strategy to adapt to changes in working conditions. At the same time, a calculation model for the demagnetization time is established based on rigorous theoretical analysis, improving the calculation accuracy and providing a reliable basis for determining the turn-on time of the low-side switch in the subsequent stage.

[0066] As Figure 3 shown, it is known that the hybrid flyback topology converter operates in the CrM mode, and the excitation current I MAG will drop from the peak to a negative value within the turn-on time T ON_LS of the low-side switch. This negative current is used to push the midpoint voltage V SW to VIN. That is to say, make the VDS voltage of the high-side switch zero. Thus, zero-voltage-switching turn-on is achieved. The magnitude of this negative current depends on the inductor and the total capacitance. Theoretically, a comparator can be used to compare the primary current I HB of the transformer with the negative current reference value I MAGneg , and when the primary current I HB is less than or equal to the negative current reference value I MAGneg , turn off the low-side switch. However, the actual problem is that the resonant current I TANK cannot be detected, and the current I HB that can be detected is the excitation current during the conduction of the high-side switch. When the low-side switch conducts, neither the resonant current I TANK nor the excitation current I MAG is detected.

[0067] For this reason, the present invention provides a method for estimating the negative current. Referring to Figure 6 and Figure 7 , the specific implementation manner of calculating the negative resonant time in the control method of the hybrid flyback topology converter is supplemented and described as follows:

[0068] Step S210: Set the positive current reference value.

[0069] Positive current reference value I MAGZCS It is used to monitor the change state of the exciting current. During the setting process, the noise characteristics in the actual operation of the flyback hybrid converter need to be considered to make the positive current reference value I MAGZCS maintained within a reasonable range. The positive current reference value I MAGZCS should be set to ensure that it is greater than the basic noise level of the circuit, but not too high, to ensure effective monitoring of the exciting current state. The reasonable setting of the positive current reference value I MAGZCS has an important impact on subsequent signal analysis and time calculation.

[0070] Step S220: Detect the exciting current during the turn-on period of the high-side switch.

[0071] The detection of the exciting current I MAG is completed by using the existing current detection circuit. During the turn-on period of the high-side switch, the exciting current I MAG rises gradually from a negative value. By monitoring the real-time change trend of the exciting current I MAG , the key information of the current change can be obtained. This step requires ensuring that the detection circuit has sufficient sampling rate and accuracy to accurately capture the change characteristics of the exciting current I MAG .

[0072] Step S230: Compare the exciting current with the positive current reference value to generate a pulse signal.

[0073] Based on the detected exciting current I MAG and the pre-set positive current reference value I MAGZCS , a pulse signal pulse_neg is generated. The rising edge of the high-side switch is used as the trigger signal for generating the pulse signal. When the exciting current I MAG exceeds the positive current reference value I MAGZCS , the pulse signal pulse_neg is terminated. By measuring the pulse width of the obtained pulse signal and comparing it with the preset threshold, it can be judged whether the negative resonance time is in the optimal state.

[0074] Step S240: Adjust the negative resonance time according to the pulse signal.

[0075] Based on the analysis result of the pulse signal pulse_neg, a dynamic optimization strategy is adopted to adjust the negative resonance time. The adjustment process follows specific control rules: when the pulse width is less than the preset threshold, it indicates insufficient negative resonance and the negative resonance time needs to be extended; when the pulse width is greater than the preset threshold, it indicates excessive negative resonance and the negative resonance time needs to be shortened; when the pulse width is equal to the preset threshold, the negative resonance time remains unchanged. Through continuous optimization in multiple switching cycles, the negative resonance time gradually approaches the optimal value.

[0076] Through the above embodiments, the accurate calculation and dynamic optimization of the negative resonance time are achieved. This method does not require adding an additional current detection circuit, and indirectly monitors the negative resonance state by analyzing the existing signals. In practical applications, this method has strong adaptability and can adjust the negative resonance time in real time according to the changes in working conditions to ensure that the system always maintains the optimal working state.

[0077] Refer to Figure 8 , and the setting method of the forward current reference value in the control method of the hybrid flyback topology converter is supplemented as follows:

[0078] Step S211: Obtain the noise reference value of the hybrid flyback topology converter.

[0079] The noise reference value reflects the background noise level of the circuit during actual operation. During the acquisition process, multiple noise sources of the circuit need to be considered, including switching noise, electromagnetic interference, and the noise of the detection circuit itself, etc. By analyzing the noise characteristics of the circuit in different working states, a reasonable noise reference value can be determined. The accurate acquisition of the noise reference value has important guiding significance for the subsequent setting of the forward current reference value.

[0080] Step S212: Set the forward current reference value, and the forward current reference value is greater than the noise reference value.

[0081] Based on the previously obtained noise reference value, set an appropriate forward current reference value. The forward current reference value needs to be maintained within a reasonable range: the lower limit should be higher than the noise reference value to ensure that the detection result is not affected by noise; the upper limit should fully consider the actual application requirements to avoid a decrease in detection sensitivity due to too high a reference value. During the setting process, multiple factors such as the dynamic characteristics of the system, measurement accuracy requirements, and anti-interference performance need to be comprehensively considered. The reasonable setting of the forward current reference value directly affects the accuracy of the negative resonance time calculation.

[0082] Refer to Figure 9 , and the specific implementation method of generating the pulse signal in the control method of the hybrid flyback topology converter is supplemented as follows:

[0083] Step S231: Generate a pulse signal with the rising edge of the high-side switch tube as the trigger signal.

[0084] The rising edge of the high-side switch tube has clear timing characteristics and can be used as the trigger source for generating the pulse signal. In this step, the system detects the rising edge of the high-side switch tube drive signal and uses it as the starting point of the pulse signal. The selection of the trigger signal needs to ensure the accuracy and stability of the timing, and the rising edge of the high-side switch tube just meets this requirement.

[0085] Step S232: Terminate the pulse signal when the exciting current is greater than the forward current reference value.

[0086] The system continuously monitors the change of the exciting current, and compares the detected exciting current value with the preset forward current reference value in real time. When it is detected that the exciting current exceeds the forward current reference value for the first time, the system immediately terminates the output of the pulse signal. The choice of the termination moment is directly related to the width of the pulse signal, and further affects the calculation accuracy of the negative resonance time.

[0087] Step S233: Measure the pulse width of the pulse signal.

[0088] Measure the width of the generated pulse signal to obtain the time interval between the trigger moment and the termination moment. The pulse width measurement requires sufficient time resolution to ensure the accuracy of the measurement result. During the measurement process, the system uses a high-precision timing unit to ensure the reliability of the pulse width data.

[0089] Step S234: Compare the pulse width with a preset threshold. The system compares the measured pulse width of the pulse signal with the preset threshold to determine whether the current negative resonance time is in the optimal state. The choice of the preset threshold needs to be based on the theoretical analysis and actual operation experience of the system to ensure the rationality of the comparison result. The comparison result of the pulse width and the threshold will be used to guide the adjustment direction of the negative resonance time.

[0090] See Figure 10 、 Figure 11 and Figure 12 For the supplementary description of the implementation method of the negative resonance time adjustment mechanism in the control method of the hybrid flyback topology converter, the following is as follows:

[0091] Step S241: Initialize the negative resonance time.

[0092] The system sets the initial value of the negative resonance time as the starting point for subsequent dynamic adjustment. The initial value setting takes into account multiple working parameters, including factors such as the exciting inductance of the transformer, the working frequency, and the input voltage. Although the initial state may not be the optimal working point, it is sufficient to ensure the safe and stable operation of the system. The initialization stage establishes the reference working state for the system and provides a reference basis for subsequent optimization and adjustment.

[0093] Step S242: When the pulse width is less than the preset threshold, extend the negative resonance time by a preset adjustment step.

[0094] See Figure 11 As shown, when the measured pulse width of the pulse signal is less than the preset threshold, it indicates that the exciting current has not reached the negative target value and the negative current peak value is small. At this time, the system needs to extend the negative resonance time to increase the negative current peak value to ensure zero voltage switching. The extension process is carried out according to the preset adjustment step to ensure the smooth transition of the system working state.

[0095] Step S243: When the pulse width is greater than a preset threshold, shorten the negative resonance time by a preset adjustment step.

[0096] Refer to Figure 12 As shown, when the measured pulse signal width is greater than the preset threshold, it indicates that the excitation current exceeds the negative target value and the negative current peak is too large. The system needs to shorten the negative resonance time, reduce the negative current peak, and avoid additional power loss. The shortening process also follows the preset adjustment step to ensure the smooth improvement of system performance.

[0097] Step S244: When the pulse width is equal to the preset threshold, keep the negative resonance time unchanged.

[0098] The equality of the pulse signal width and the preset threshold indicates that the negative resonance time has reached the optimal state. During the maintenance phase, the system continues to monitor the change of the pulse signal and track the working state in real time. If it is detected that the working conditions change, the system will re-enter the adjustment phase to ensure that the optimal performance is always maintained.

[0099] Through the above implementation manner, a complete optimization mechanism is formed. The system adjusts the negative resonance time by a progressive method based on the analysis result of the pulse signal. Each adjustment cycle includes three links: signal detection, data analysis, and time adjustment, and the performance is optimized through continuous iteration. The selection of the adjustment step weighs the optimization speed and the requirements of system stability, avoiding drastic fluctuations.

[0100] Different from the prior art, the embodiment of the present invention determines the turn-on time of the low-end switch tube by calculating the demagnetization time of the transformer, that is, the time when the excitation current drops from the peak to zero, and the negative resonance time, that is, the time when the excitation current drops from zero to a preset reference value. Without changing the original topology structure, it not only avoids the power loss caused by adding an additional detection circuit, but also overcomes the problem of low accuracy of the traditional volt-second balance method. Through real-time calculation and adjustment, it can accurately control the switching timing and effectively improve the system efficiency and reliability.

[0101] The embodiment of the present invention also provides an integrated circuit based on the above control method of the hybrid flyback topology converter. This integrated circuit is different from the general integrated circuit, and its function is to execute special functions, such as controlling the hybrid flyback topology converter and executing the control method of the hybrid flyback topology converter for implementing the above method embodiments.

[0102] The embodiment of the present invention also provides an electronic device based on the above control method of the hybrid flyback topology converter. The schematic structural diagram is as Figure 13 shown. The electronic device 10 includes:

[0103] One or more processors, a network interface 12, and a memory 13,Figure 13 Take a processor, a network interface 12, and a memory 13 as an example.

[0104] The network interface 12 is communicatively connected to the corresponding processor. The processor and the memory 12 can be connected through a bus or other means. Figure 13 Take the connection through a bus as an example.

[0105] The network interface 12 is used to establish a communication connection between the processor and other external devices, including the following types: RJ-45 interface, SC fiber optic interface, AUI interface, FDDI interface, and Console interface, etc.

[0106] The memory 13, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules. The processor executes various functional applications and data processing of the electronic device by running the non-volatile software programs, instructions, and units stored in the memory 13, that is, to implement the control method of the hybrid flyback topology converter in the above method embodiments.

[0107] The memory 13 can include a program storage area and a data storage area. Among them, the program storage area can store an operating system and application programs required for at least one function; the data storage area can store data created according to the use of the electronic device, etc. In addition, the memory 13 can include high-speed random access memory, and can also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other non-volatile solid-state storage devices. In some embodiments, the memory 13 optionally includes a memory remotely set relative to the processor, and these remote memories can be connected to the electronic device through a network. Examples of the above network include but are not limited to the Internet, enterprise intranet, local area network, mobile communication network, and their combinations.

[0108] The one or more units are stored in the memory 13 and, when executed by one or more processors, execute the control method of the hybrid flyback topology converter in any of the above method embodiments. For example, execute the Figure 3 method steps S100 to step S400 described above.

[0109] The above electronic device can execute the control method of the hybrid flyback topology converter provided by the embodiments of the present invention, and has corresponding program modules and beneficial effects for executing the method. For technical details not described in detail in the electronic device embodiments, reference can be made to the control method of the hybrid flyback topology converter provided by the embodiments of the present invention.

[0110] An embodiment of the present invention further provides a non-volatile computer-readable storage medium, which may be included in the device described in the above embodiment; or may exist alone without being assembled into the device. The above non-volatile computer-readable storage medium carries one or more programs, and when the one or more programs are executed, the control method of the hybrid flyback topology converter in the embodiments of the present disclosure is implemented.

[0111] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limiting them; under the idea of the present application, the technical features in the above embodiments or different embodiments can also be combined, and the steps can be implemented in any order, and there are many other changes in different aspects of the present application as above. For the sake of brevity, they are not provided in detail; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A control method for a hybrid flyback topology converter, characterized in that: include: Calculate the demagnetization time of the transformer; The demagnetization time is the time it takes for the excitation current to drop from the peak value to zero; Calculate negative resonance time; The negative resonance time is the time it takes for the excitation current to drop from zero to a preset reference value; The turn-on time of the low-end switch tube is obtained according to the demagnetization time and the negative resonance time.

2. The method according to claim 1, characterized in that The step of calculating the demagnetization time of the transformer comprises: Get the peak reference value of the peak current comparator; Collecting equivalent excitation inductance parameters of the transformer; Detecting the voltage value applied to the excitation inductor; The demagnetization time is calculated based on the peak reference value, the equivalent excitation inductance parameter and the voltage value.

3. The method according to claim 2, characterized in that The peak reference value is calculated according to the following formula: I MPEAK·RS =V COMP , Among them, V COMP is the compensation voltage, I MPEAK is the peak reference value, R S is a detection resistor; the compensation voltage is an equivalent voltage obtained by transforming the secondary voltage value of the transformer; The demagnetization time is calculated according to the following formula: Among them, T ON_LS1 is the demagnetization time, N·V OUT is the voltage value, L M is the equivalent excitation inductance parameter.

4. The method according to claim 1, characterized in that: The calculating of the negative resonance time comprises: Set the forward current reference value; Detecting the excitation current during the on-state of the high-end switch tube; comparing the excitation current with the forward current reference value to generate a pulse signal; The negative resonance time is adjusted according to the pulse signal.

5. The method according to claim 4, characterized in that The setting of the forward current reference value includes: Obtaining a noise reference value of the hybrid flyback topology converter; The forward current reference value is set, and the forward current reference value is greater than the noise baseline value.

6. The method according to claim 4, characterized in that The generating of the pulse signal comprises: The pulse signal is generated by taking the rising edge of the high-end switch tube as a trigger signal; When the excitation current is greater than the forward current reference value, terminating the pulse signal; measuring the pulse width of the pulse signal; The pulse width is compared with a preset threshold.

7. The method according to claim 6, characterized in that The adjusting the negative resonance time according to the pulse signal includes: Initializing the negative resonance time; When the pulse width is less than the preset threshold, extending the negative resonance time according to a preset adjustment step; When the pulse width is greater than the preset threshold, shortening the negative resonance time according to the preset adjustment step; When the pulse width is equal to the preset threshold, the negative resonance time is maintained unchanged.

8. An integrated circuit, characterized in that: include: A controller, wherein the controller is used to control a hybrid flyback topology converter and execute a control method for a hybrid flyback topology converter according to any one of claims 1 to 7.

9. An electronic device, characterized in that: include: at least one processor; at least one network interface, the network interface being communicatively connected to a corresponding processor; as well as, a memory communicatively connected to the at least one processor; wherein, The network interface is used to establish a communication connection between the processor and other external devices; The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the control method of the hybrid flyback topology converter according to any one of claims 1 to 7.

10. A non-volatile computer storage medium, characterized in that: The computer storage medium stores computer executable instructions, which are executed by one or more processors, so that the one or more processors can execute the control method of the hybrid flyback topology converter according to any one of claims 1 to 7.

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