Resonant parameter determination method and device of direct-direct converter, electronic equipment and medium

Abstract

This invention provides a method, apparatus, electronic device, and dielectric for determining the resonant parameters of a DC-DC converter, relating to the field of power electronics technology. The method includes: determining the initial electrical parameters of the power switching devices in the DC-DC converter based on preset electrical parameters; determining the initial resonant inductance value of the resonant network in the DC-DC converter based on the initial electrical parameters and preset electrical parameters; determining the optimized magnetizing inductance value corresponding to the resonant network based on the initial electrical parameters and the high-frequency resonant phase angle during the dead time; ensuring the optimized magnetizing inductance value satisfies the zero-voltage turn-on condition; and determining the target resonant parameters in the DC-DC converter that satisfy the target voltage gain based on the optimized magnetizing inductance value and the initial resonant inductance value. This invention optimizes the parameter range of the magnetizing inductance based on the coupling relationship between the magnetizing inductance and the high-frequency resonant phase angle during the dead time, ensuring that the optimized magnetizing inductance value of the resonant network can satisfy the zero-voltage turn-on condition.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, and in particular to a method, apparatus, electronic device, and dielectric for determining the resonant parameters of a DC-DC converter. Background Technology

[0002] DC-DC converters are used to convert a fixed DC voltage into a variable DC voltage. They are widely used in power electronic systems, such as the DC bus power supply system of urban rail trains. The DC-DC converter converts the input high-voltage DC power into low-voltage DC power, so that electrical energy can be transferred from the power supply system to the load end, achieving efficient power conversion.

[0003] Currently, in DC-DC converters, SiC MOSFET power devices exhibit high-frequency switching characteristics with high voltage and current change rates, making them extremely sensitive to parasitic parameters in the circuit. This leads to high-frequency voltage and current oscillations during the dead time of the zero-voltage-switching (ZVS) resonant phase. Due to this non-ideal characteristic, the junction capacitance voltage reverses after the resonant current crosses zero, resulting in the loss of zero-voltage turn-on, i.e., soft-switching failure. At high power levels, the high-frequency resonant current is mainly composed of AC components, significantly affecting the charging and discharging of the junction capacitance, preventing SiC MOSFET power devices from achieving zero-voltage turn-on. Therefore, providing a method for determining the resonant parameters to achieve zero-voltage turn-on is a pressing technical problem that needs to be solved. Summary of the Invention

[0004] This invention provides a method, apparatus, electronic device, and dielectric for determining the resonant parameters of a DC-DC converter, in order to solve the defect of soft switching loss in existing DC-DC converters.

[0005] This invention provides a method for determining the resonant parameters of a DC-DC converter, comprising the following steps.

[0006] Based on the preset electrical parameters of the DC-DC converter, the initial electrical parameters of the power switching devices in the DC-DC converter are determined; Based on the initial electrical parameters and the preset electrical parameters, the initial resonant inductance value of the resonant network in the DC-DC converter is determined; Based on the initial electrical parameters and the high-frequency resonant phase angle during the dead time, the optimized excitation inductance value corresponding to the resonant network is determined; the optimized excitation inductance value satisfies the zero-voltage turn-on condition. Based on the optimized excitation inductance value and the initial resonant inductance value, the target resonant parameters that satisfy the target voltage gain in the DC-DC converter are determined.

[0007] According to the method for determining the resonant parameters of a DC-DC converter provided by the present invention, determining the optimized excitation inductance value corresponding to the resonant network based on the initial electrical parameters and the high-frequency resonant phase angle during the dead time includes: Based on the initial electrical parameters and the primary-side electrical parameters of the primary-side switching network in the DC-DC converter, the expression for the target magnetizing inductance is determined. Based on the high-frequency resonant phase angle and the target excitation inductance expression, an excitation inductance constraint model is constructed; the excitation inductance constraint model is used to characterize whether the excitation inductance range of zero-voltage switching is satisfied. Based on the excitation inductance constraint model, the optimal excitation inductance value that satisfies the zero-voltage turn-on condition in the resonant network is determined.

[0008] According to the method for determining the resonant parameters of a DC-DC converter provided by the present invention, the step of constructing an excitation inductance constraint model based on the high-frequency resonant phase angle and the expression for the target excitation inductance includes: Based on the expression for the target excitation inductance, the partial derivative of the high-frequency resonant phase angle is obtained to get the maximum starting phase angle and the maximum ending phase angle. Based on the maximum starting phase angle and the maximum ending phase angle, the range of excitation inductance corresponding to the target excitation inductance expression is partitioned to obtain the excitation inductance constraint model.

[0009] According to the method for determining the resonant parameters of a DC-DC converter provided by the present invention, determining the target excitation inductance expression based on the initial electrical parameters and the primary-side electrical parameters of the primary-side switching network in the DC-DC converter includes: Based on the initial electrical parameters and the primary-side electrical parameters of the primary-side switching network in the DC-DC converter, the junction capacitance voltage corresponding to the power switching device is determined; When the junction capacitance voltage is less than or equal to 0, determine the expression for the first magnetizing inductance; Based on the first excitation inductance expression, the target excitation inductance expression is determined.

[0010] According to the method for determining the resonant parameters of a DC-DC converter provided by the present invention, determining the initial resonant inductance value of the resonant network in the DC-DC converter based on the initial electrical parameters and the preset electrical parameters includes: The target quality factor is determined based on a preset correlation relationship and a preset resonant capacitor voltage; the preset correlation relationship is used to characterize the correlation between the quality factor and the voltage gain. Based on the target quality factor, the initial resonant inductance value of the resonant network in the DC-DC converter is determined.

[0011] According to the method for determining the resonant parameters of a DC-DC converter provided by the present invention, determining the target resonant parameters of the DC-DC converter that satisfy the target voltage gain based on the optimized magnetizing inductance value and the initial resonant inductance value includes: Based on the optimized excitation inductance value and the initial resonant inductance value, the normalized frequency ratio is determined. The resonant frequency is determined based on the target quality factor, the initial resonant inductance value, and the preset electrical parameters. The resonant frequency ratio is determined based on the resonant frequency and the switching frequency in the initial electrical parameters; The gain of the voltage to be measured is determined based on the resonant frequency ratio, the normalized frequency ratio, and the target quality factor. When the voltage gain under test meets the target voltage gain, the initial resonant inductance value, the optimized magnetizing inductance value, and the initial electrical parameters of the power switching device are determined as the target resonant parameters in the DC-DC converter that meet the target voltage gain.

[0012] According to the method for determining the resonant parameters of a DC-DC converter provided by the present invention, the preset electrical parameters include input voltage, output voltage, input power, and equivalent load; the initial electrical parameters include the transformer turns ratio, switching frequency, and dead time.

[0013] The present invention also provides a device for determining the resonant parameters of a DC-DC converter, comprising the following modules.

[0014] The first determining module is used to determine the initial electrical parameters of the power switching devices in the DC-DC converter based on the preset electrical parameters of the DC-DC converter; The second determining module is used to determine the initial resonant inductance value of the resonant network in the DC-DC converter based on the initial electrical parameters and the preset electrical parameters. The third determining module is used to determine the optimized excitation inductance value corresponding to the resonant network based on the initial electrical parameters and the high-frequency resonant phase angle during the dead time; the optimized excitation inductance value satisfies the zero-voltage turn-on condition; The fourth determining module is used to determine the target resonant parameters in the DC-DC converter that satisfy the target voltage gain based on the optimized excitation inductance value and the initial resonant inductance value.

[0015] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the resonant parameter determination method of any of the above-described DC-DC converters.

[0016] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for determining the resonant parameters of a DC-DC converter as described above.

[0017] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the method for determining the resonant parameters of the DC-DC converter as described above.

[0018] This invention provides a method, apparatus, electronic device, and dielectric for determining the resonant parameters of a DC-DC converter. It determines the initial electrical parameters during power switching in the DC-DC converter using preset electrical parameters. Based on the initial and preset electrical parameters, it determines the initial resonant inductance value of the resonant network. Based on the initial electrical parameters and the high-frequency resonant phase angle during the dead time, it determines the optimized magnetizing inductance value corresponding to the resonant network that satisfies the zero-voltage turn-on condition. Based on the optimized magnetizing inductance value and the initial resonant inductance value, it determines the target resonant parameters in the DC-DC converter that satisfy the target voltage gain. In this invention, based on the initial electrical parameters, the high-frequency resonant phase angle during the dead time is introduced. Based on the coupling relationship between the magnetizing inductance and the high-frequency resonant phase angle, the parameter range of the magnetizing inductance is optimized to ensure that the optimized magnetizing inductance value of the resonant network can meet the zero-voltage turn-on condition, effectively reducing switching losses and electromagnetic interference. This is applicable to high-frequency device scenarios such as SiC MOSFETs. Simultaneously, through parametric modeling, it avoids the limitations of traditional trial-and-error methods, improving the design accuracy and reliability of the resonant parameters. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a flowchart illustrating the method for determining the resonant parameters of a DC-DC converter provided in an embodiment of the present invention.

[0021] Figure 2 This is a schematic diagram of the topology of the direct-to-direct-current converter provided in an embodiment of the present invention.

[0022] Figure 3 This is a schematic diagram of the preset association relationship provided in the embodiments of the present invention.

[0023] Figure 4 This is a schematic diagram of the resonant parameter determination device for a DC-DC converter provided in an embodiment of the present invention.

[0024] Figure 5 This is a schematic diagram of the structure of the electronic device provided in an embodiment of the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0026] To address the problem of soft switching loss in existing DC-DC converters, this invention provides a method for determining the resonant parameters of a DC-DC converter. Figure 1 This is a flowchart illustrating the method for determining the resonant parameters of a DC-DC converter provided in an embodiment of the present invention, as shown below. Figure 1 As shown, the method includes steps 110 to 140.

[0027] Step 110: Determine the initial electrical parameters of the power switching devices in the DC-DC converter based on the preset electrical parameters of the DC-DC converter.

[0028] For example, taking this DC-DC converter as a full-bridge LLC resonant converter as an example, Figure 2 This is a schematic diagram of the topology of the direct-to-direct-current converter provided in an embodiment of the present invention, as shown below. Figure 2 As shown, the DC-DC converter includes a primary-side switching network, a resonant network, and a secondary-side rectifier network. The primary-side switching network includes four power switching devices, the secondary-side rectifier network includes four rectifier switches, and the resonant network includes a resonant capacitor, a resonant inductor, a magnetizing inductor, and a transformer.

[0029] Furthermore, the preset electrical parameters include input voltage, output voltage, input power, and equivalent load; the initial electrical parameters include the transformer's turns ratio, switching frequency, and dead time. Specifically, the ratio of the output voltage to the input voltage is calculated; this ratio is the transformer's turns ratio, expressed as: n = V out / V in , n represents the turns ratio of the transformer, V out Indicates the output voltage, V in This represents the input voltage. Based on the input power and equivalent load, the switching frequency and dead time that meet the application requirements are determined. This switching frequency is greater than the resonant frequency of the three components (resonant inductor, magnetizing inductor, and resonant capacitor), but less than the resonant frequency of the resonant inductor and resonant capacitor alone. The dead time is related to the turn-on and turn-off times of the power switching device. Therefore, a suitable power switching device can be selected based on the switching frequency, dead time, voltage stress, and current stress.

[0030] Step 120: Based on the initial electrical parameters and the preset electrical parameters, determine the initial resonant inductance value of the resonant network in the DC-DC converter.

[0031] Specifically, after determining the initial electrical parameters and the preset electrical parameters, the initial resonant inductance value of the resonant inductor in the resonant network is initially determined based on the initial electrical parameters and the preset electrical parameters, so as to be verified in step 140.

[0032] Step 130: Based on the initial electrical parameters and the high-frequency resonant phase angle during the dead time, determine the optimized excitation inductance value corresponding to the resonant network; the optimized excitation inductance value satisfies the zero-voltage turn-on condition.

[0033] Specifically, the design of resonant parameters affects soft-switching performance. In existing technologies, the design accuracy of resonant parameters is low due to considerations of dead time, magnetizing inductor current, and the shunt effect of secondary-side parasitic capacitance, resulting in a negligible impact on soft-switching performance. Furthermore, existing technologies only address traditional SiC MOSFET devices and fail to consider the high-frequency resonance of SiC MOSFET devices during the dead time, leading to a reduction in soft-switching performance. Therefore, in this embodiment of the invention, a high-frequency resonant phase angle during the dead time is introduced based on the initial electrical parameters. Based on the coupling relationship between the magnetizing inductor and the high-frequency resonant phase angle, the parameter range of the magnetizing inductor is optimized to ensure that the optimized magnetizing inductance value of the resonant network can meet the zero-voltage turn-on condition, thereby improving the soft-switching performance of the DC-DC converter.

[0034] It should be noted that the zero-voltage turn-on condition refers to reducing the voltage across the power switching device to zero before the device is turned on, thus achieving zero-voltage turn-on. Soft switching includes both the zero-voltage turn-on condition and the zero-current turn-off condition of the secondary rectifier-side switching transistor. Meeting the zero-voltage turn-on condition also meets the zero-current turn-off condition.

[0035] Step 140: Based on the optimized excitation inductance value and the initial resonant inductance value, determine the target resonant parameters in the DC-DC converter that satisfy the target voltage gain.

[0036] Specifically, after determining the optimized excitation inductance value and the initial resonant inductance value, the voltage gain to be measured is determined based on the optimized excitation inductance value and the initial resonant inductance value. The voltage gain to be measured is then verified to determine whether the target voltage gain is met. If the target voltage gain is met, the target resonant parameters are determined. If the target voltage gain is not met, the optimized excitation inductance value and the initial resonant inductance value are adjusted until the voltage gain to be measured meets the target voltage gain.

[0037] The resonant parameter determination method for DC-DC converters provided in this invention determines the initial electrical parameters during power switching in the DC-DC converter using preset electrical parameters. Based on the initial and preset electrical parameters, the initial resonant inductance value of the resonant network is determined. Then, based on the initial electrical parameters and the high-frequency resonant phase angle during the dead time, the optimized magnetizing inductance value corresponding to the resonant network that satisfies the zero-voltage turn-on condition is determined. Finally, based on the optimized magnetizing inductance value and the initial resonant inductance value, the target resonant parameters in the DC-DC converter that satisfy the target voltage gain are determined. In this invention, based on the initial electrical parameters, the high-frequency resonant phase angle during the dead time is introduced. Based on the coupling relationship between the magnetizing inductance and the high-frequency resonant phase angle, the parameter range of the magnetizing inductance is optimized to ensure that the optimized magnetizing inductance value of the resonant network can meet the zero-voltage turn-on condition, effectively reducing switching losses and electromagnetic interference. This method is applicable to high-frequency device scenarios such as SiC MOSFETs. Simultaneously, through parametric modeling, the limitations of traditional trial-and-error methods are avoided, improving the design accuracy and reliability of the resonant parameters.

[0038] In one embodiment, determining the initial resonant inductance value of the resonant network in the DC-DC converter based on the initial electrical parameters and the preset electrical parameters includes: The target quality factor is determined based on a preset correlation relationship and a preset resonant capacitor voltage; the preset correlation relationship is used to characterize the correlation between the quality factor and the voltage gain. Based on the target quality factor, the initial resonant inductance value of the resonant network in the DC-DC converter is determined.

[0039] Specifically, the preset resonant capacitor voltage is the maximum voltage across the resonant capacitor in the resonant network. Based on historical engineering experience, this preset resonant capacitor voltage is 0.7 to 0.85 times the input voltage. The preset resonant capacitor voltage is shown in equation (1), which is: .

[0040] in, This indicates the preset resonant capacitor voltage. This represents the input voltage, and Q represents the quality factor. This represents the normalized resonance ratio, and , Indicates the switching frequency. This represents the resonant frequency of the resonant circuit formed by the resonant inductor and the resonant capacitor.

[0041] Figure 3 This is a schematic diagram of the preset association relationship provided in the embodiments of the present invention, such as... Figure 3As shown, the preset correlation is represented by voltage gain curves under different quality factors. Based on the preset correlation, the quality factor range in region ② is determined. With the preset resonant capacitor voltage obtained and the normalized frequency ratio equal to 1, the maximum quality factor within this quality factor range is calculated using equation (1), and this maximum quality factor is determined as the target quality factor.

[0042] The expression for the quality factor is derived by fundamental frequency analysis of the LLC circuit, as shown in equation (2). Equation (2) is: .

[0043] in, This represents the initial resonant inductance value of the resonant inductor. This represents the load impedance.

[0044] When the normalized frequency ratio is equal to 1, the resonant frequency is equal to the switching frequency. Substituting the target quality factor, resonant frequency, transformer turns ratio, and load impedance into equation (2), the initial resonant inductance value corresponding to the resonant inductance can be calculated.

[0045] Furthermore, the expression for the resonant frequency is shown in equation (3), which is: .

[0046] in, This represents the resonant capacitor.

[0047] Given the resonant frequency and the initial resonant inductance value corresponding to the resonant inductance, the capacitance value of the resonant capacitor can be determined by substituting the resonant frequency and the initial resonant inductance value corresponding to the resonant inductance into equation (3).

[0048] In one embodiment, determining the optimized excitation inductance value corresponding to the resonant network based on the initial electrical parameters and the high-frequency resonant phase angle within the dead time includes: Based on the initial electrical parameters and the primary-side electrical parameters of the primary-side switching network in the DC-DC converter, the expression for the target magnetizing inductance is determined. Based on the high-frequency resonant phase angle and the target excitation inductance expression, an excitation inductance constraint model is constructed; the excitation inductance constraint model is used to characterize the excitation inductance range that satisfies the zero-voltage turn-on condition. Based on the excitation inductance constraint model, the optimal excitation inductance value that satisfies the zero-voltage turn-on condition in the resonant network is determined.

[0049] Specifically, during the dead time of the DC-DC converter, the junction capacitance of the power switching device is charged and discharged through the resonant current. Soft switching of the power switching device can be achieved when the electrical parameters of the resonant circuit meet specific conditions. Soft switching analysis is typically based on the primary-side switching network. The primary-side electrical parameters of the primary-side switching network include, but are not limited to: junction capacitance voltage, charge equivalent capacitance, impedance equivalent capacitance, secondary-side diode junction capacitance, transformer parasitic capacitance, and the high-frequency resonant angular frequency during the dead time. Based on these primary-side electrical parameters and the initial electrical parameters, the target magnetizing inductance expression is determined. Since the resonant period count is usually non-integer, the magnetizing inductance determined by the target magnetizing inductance expression has a certain error, resulting in low design accuracy of the resonant parameters. Therefore, in this embodiment of the invention, a partial derivative of the target magnetizing inductance expression with respect to the high-frequency resonant phase angle is introduced to construct a magnetizing inductance constraint model. This magnetizing inductance constraint model partitions the range of magnetizing inductance values, resulting in the following three magnetizing inductance intervals.

[0050] (1) The range of values ​​corresponding to the excitation inductance interval 1 is (0, L) m_min Within this range, the DC-DC converter can stably achieve soft-switching operation. Under these conditions, there is no need for special design or compensation for the additional effects caused by the high-frequency resonant current during the dead time. This is because the resonant behavior within this range has a limited impact on the overall system operation, and the set dead time can fully complete the charging and discharging process of the parasitic capacitance of the power switching devices, thereby ensuring that the power switch achieves zero-voltage or near-zero-voltage switching during conduction and turn-off. The parameter design in this range is mainly used to meet the requirements of normal operation and basic function realization of the converter.

[0051] (2) The range of values ​​corresponding to the excitation inductance interval 2 is (L m_min L m_max This range constitutes the critical operating range for soft-switching operation of the DC-DC converter. Within this range, the soft-switching conditions of the power switch during commutation can only be guaranteed by analyzing the phase relationship of the high-frequency resonant current. As the magnetizing inductance parameter increases, the time-domain and phase characteristics of the resonant current gradually strengthen, and its influence on the switching transient process increases accordingly. Therefore, in the design process within this parameter range, the magnetizing inductance needs to be comprehensively optimized to meet the soft-switching conditions while considering the system's energy conversion efficiency, thereby ensuring that the DC-DC converter maintains a stable soft-switching state throughout the entire operation.

[0052] (3) The range of values ​​corresponding to the excitation inductance interval 3 is (L m_maxWithin this range (∞), due to the excessively large value of the magnetizing inductance, the rate of change of the high-frequency resonant current is limited, making it impossible to complete the energy transfer and voltage transition of the parasitic capacitance of the power switching device within the preset dead time. This makes it difficult for the power switch to meet the soft-switching conditions during commutation. Consequently, hard-switching will occur, resulting in a significant increase in switching losses and the voltage and current stress on the devices, which in turn will adversely affect the overall efficiency and operational reliability of the DC-DC converter.

[0053] In this excitation inductance constraint model, the excitation inductance interval 2 is the optimal operating interval for achieving efficient and stable operation. Therefore, any excitation inductance value in the excitation inductance interval 2 can be determined as the optimized excitation inductance value that satisfies the zero-voltage turn-on condition in the resonant network.

[0054] In one embodiment, determining the target magnetizing inductance expression based on the initial electrical parameters and the primary-side electrical parameters of the primary-side switching network in the DC-DC converter includes: Based on the initial electrical parameters and the primary-side electrical parameters of the primary-side switching network in the DC-DC converter, the junction capacitance voltage corresponding to the power switching device is determined; When the junction capacitance voltage is less than or equal to 0, determine the expression for the first magnetizing inductance; Based on the first excitation inductance expression, the target excitation inductance expression is determined.

[0055] Specifically, the junction capacitance voltage expression of the power switching device is shown in equation (4), which is: .

[0056] in, This represents the junction capacitance voltage at time t. Represents the charge-equivalent capacitance. Represents the impedance equivalent capacitance. This indicates the junction capacitance of the secondary diode. Indicates the parasitic capacitance of the transformer. This represents the high-frequency resonant angular frequency during the dead time. Indicates the output voltage, in At any given moment, the drain-source voltage v of the power switching device ds Reaching bus voltage V DC .

[0057] According to the zero-voltage turn-on condition or soft-switching condition, the junction capacitance voltage should remain less than or equal to 0 before the dead time ends. Therefore, the expression for the first magnetizing inductance can be determined according to equation (4), which is shown in equation (5). Equation (5) is: .

[0058] Then, the corresponding parameters in the expression for the first excitation inductance are equivalently replaced by the high-frequency resonant phase angle to obtain the expression for the target excitation inductance shown in equation (6). Equation (6) is: .

[0059] The high-frequency resonant phase angle includes the starting phase angle and the ending phase angle, θ. sta θ represents the initial phase angle. end Indicates the termination phase angle; ; ; ; .

[0060] It should be noted that during the dead time, the resonant current satisfies i Lr =i Lm Therefore, equation (5) can be used to derive the expression for the second excitation inductance shown in equation (7), which is: .

[0061] Among them, V out That is, V o That is, the output voltage, C Q This represents the diode junction capacitance in the primary-side resonant network.

[0062] Furthermore, considering the effect of the secondary diode junction capacitance on the excitation current i Lm When the current shunting effect occurs, the resonant current and the excitation current are no longer equal. At this time, the resonant current at time t is as shown in equation (8), which is: .

[0063] Based on equation (8), the expression for the third excitation inductance shown in equation (9) can be derived. Equation (9) is: .

[0064] In one embodiment, constructing the excitation inductance constraint model based on the high-frequency resonant phase angle and the target excitation inductance expression includes: Based on the expression for the target excitation inductance, the partial derivative of the high-frequency resonant phase angle is obtained to get the maximum starting phase angle and the maximum ending phase angle. Based on the maximum starting phase angle and the maximum ending phase angle, the range of excitation inductance corresponding to the target excitation inductance expression is partitioned to obtain the excitation inductance constraint model.

[0065] Specifically, after determining the expression for the target excitation inductance, partial derivatives are calculated for the initial phase angle and the final phase angle in the high-frequency resonant phase angle. Taking the initial phase angle as an example, the partial derivative of the initial phase angle is calculated based on the expression for the target excitation inductance, as shown in equation (10). Equation (10) is: .

[0066] The maximum initial phase angle can be determined according to equation (10), which is shown in equation (11). Equation (11) is: .

[0067] Similarly, by taking the partial derivative of the target excitation inductance expression with respect to the termination phase angle, the maximum termination phase angle can be determined. This maximum termination phase angle is shown in equation (12), which is: .

[0068] It can be seen that the starting angle and the ending angle have the same periodicity, and the period is π. Then, based on the maximum starting phase angle and the maximum ending phase angle, the maximum and minimum magnetizing inductance values ​​are determined to achieve soft switching while considering the high-frequency resonant phase angle. The intervals corresponding to the maximum and minimum magnetizing inductance values ​​are defined as magnetizing inductance interval 2 in the magnetizing inductance constraint model. The interval from 0 to the minimum magnetizing inductance value is defined as magnetizing inductance interval 1 in the magnetizing inductance constraint model. The interval from the maximum magnetizing inductance value to infinity is defined as magnetizing inductance interval 3 in the magnetizing inductance constraint model.

[0069] In one embodiment, determining the target resonant parameter in the DC-DC converter that satisfies the target voltage gain based on the optimized excitation inductance value and the initial resonant inductance value includes: Based on the optimized excitation inductance value and the initial resonant inductance value, the normalized frequency ratio is determined. The resonant frequency is determined based on the target quality factor, the initial resonant inductance value, and the preset electrical parameters. Based on the resonant frequency and the switching frequency in the initial electrical parameters, determine the normalized frequency ratio; The gain of the voltage to be measured is determined based on the resonant frequency ratio, the normalized frequency ratio, and the target quality factor. When the voltage gain under test meets the target voltage gain, the initial resonant inductance value, the optimized magnetizing inductance value, and the initial electrical parameters of the power switching device are determined as the target resonant parameters in the DC-DC converter that meet the target voltage gain.

[0070] Specifically, the ratio of the optimized excitation inductance value to the initial resonant inductance value is calculated, which is the normalized frequency ratio. Then, the target quality factor, the initial resonant inductance value, and the preset electrical parameters are substituted into equation (2) to calculate the resonant frequency. Next, the ratio of the resonant frequency to the switching frequency is calculated, which is the resonant frequency ratio. Then, using equation (13), based on the resonant frequency ratio, the normalized frequency ratio, and the target quality factor, the voltage gain to be measured is calculated. Equation (13) is: .

[0071] Where M represents the voltage gain to be measured. This represents the normalized frequency ratio.

[0072] After determining the voltage gain to be measured, compare it with the target voltage gain. If the absolute value of the difference between the voltage gain to be measured and the target voltage gain is less than or equal to a preset threshold, it indicates that the voltage gain to be measured meets the target voltage gain. In this case, the determined initial resonant inductance value, optimized magnetizing inductance value, and initial electrical parameters of the power switching device can be determined as the target resonant parameters. If the absolute value of the difference between the voltage gain to be measured and the target voltage gain is greater than the preset threshold, it indicates that the voltage gain to be measured does not meet the target voltage gain. In this case, readjust the initial resonant inductance value and the optimized magnetizing inductance value until the voltage gain to be measured meets the target voltage gain.

[0073] The resonant parameter determination device for the DC-DC converter provided by the present invention is described below. The resonant parameter determination device for the DC-DC converter described below can be referred to in correspondence with the resonant parameter determination method for the DC-DC converter described above.

[0074] This invention also provides a device for determining the resonant parameters of a DC-DC converter. Figure 4 This is a schematic diagram of the resonant parameter determination device for a DC-DC converter provided in an embodiment of the present invention, as shown below. Figure 4 As shown, the resonant parameter determination device 400 of the DC-DC converter includes: a first determination module 410, a second determination module 420, a third determination module 430 and a fourth determination module 440.

[0075] The first determining module 410 is used to determine the initial electrical parameters of the power switching devices in the DC-DC converter based on the preset electrical parameters of the DC-DC converter.

[0076] The second determining module 420 is used to determine the initial resonant inductance value of the resonant network in the DC-DC converter based on the initial electrical parameters and the preset electrical parameters.

[0077] The third determining module 430 is used to determine the optimized excitation inductance value corresponding to the resonant network based on the initial electrical parameters and the high-frequency resonant phase angle during the dead time; the optimized excitation inductance value satisfies the zero-voltage turn-on condition.

[0078] The fourth determining module 440 is used to determine the target resonant parameters in the DC-DC converter that satisfy the target voltage gain based on the optimized excitation inductance value and the initial resonant inductance value.

[0079] The resonant parameter determination device for a DC-DC converter provided in this invention determines the initial electrical parameters during power switching in the DC-DC converter based on preset electrical parameters. Based on the initial and preset electrical parameters, it determines the initial resonant inductance value of the resonant network. Based on the initial electrical parameters and the high-frequency resonant phase angle during the dead time, it determines the optimized magnetizing inductance value corresponding to the resonant network that satisfies the zero-voltage turn-on condition. Based on the optimized magnetizing inductance value and the initial resonant inductance value, it determines the target resonant parameters in the DC-DC converter that satisfy the target voltage gain. In this invention, based on the initial electrical parameters, the high-frequency resonant phase angle during the dead time is introduced. Based on the coupling relationship between the magnetizing inductance and the high-frequency resonant phase angle, the parameter range of the magnetizing inductance is optimized to ensure that the optimized magnetizing inductance value of the resonant network can meet the zero-voltage turn-on condition, effectively reducing switching losses and electromagnetic interference. This is applicable to high-frequency device scenarios such as SiC MOSFETs. Simultaneously, through parametric modeling, the limitations of traditional trial-and-error methods are avoided, improving the design accuracy and reliability of the resonant parameters.

[0080] Optionally, the preset electrical parameters include input voltage, output voltage, input power, and equivalent load; the initial electrical parameters include the transformer turns ratio, switching frequency, and dead time.

[0081] Optionally, the second determining module 420 is specifically used for: The target quality factor is determined based on a preset correlation relationship and a preset resonant capacitor voltage; the preset correlation relationship is used to characterize the correlation between the quality factor and the voltage gain. Based on the target quality factor, the initial resonant inductance value of the resonant network in the DC-DC converter is determined.

[0082] Optionally, the third determining module 430 is specifically used for: Based on the initial electrical parameters and the primary-side electrical parameters of the primary-side switching network in the DC-DC converter, the expression for the target magnetizing inductance is determined. Based on the high-frequency resonant phase angle and the target excitation inductance expression, an excitation inductance constraint model is constructed; the excitation inductance constraint model is used to characterize whether the excitation inductance range of zero-voltage switching is satisfied. Based on the excitation inductance constraint model, the optimal excitation inductance value that satisfies the zero-voltage turn-on condition in the resonant network is determined.

[0083] Optionally, the third determining module 430 is specifically used for: Based on the expression for the target excitation inductance, the partial derivative of the high-frequency resonant phase angle is obtained to get the maximum starting phase angle and the maximum ending phase angle. Based on the maximum starting phase angle and the maximum ending phase angle, the range of excitation inductance corresponding to the target excitation inductance expression is partitioned to obtain the excitation inductance constraint model.

[0084] Optionally, the third determining module 430 is specifically used for: Based on the initial electrical parameters and the primary-side electrical parameters of the primary-side switching network in the DC-DC converter, the junction capacitance voltage corresponding to the power switching device is determined; When the junction capacitance voltage is less than or equal to 0, determine the expression for the first magnetizing inductance; Based on the first excitation inductance expression, the target excitation inductance expression is determined.

[0085] Optionally, the fourth determining module 440 is specifically used for: Based on the optimized excitation inductance value and the initial resonant inductance value, the normalized frequency ratio is determined. The resonant frequency is determined based on the target quality factor, the initial resonant inductance value, and the preset electrical parameters. The resonant frequency ratio is determined based on the resonant frequency and the switching frequency in the initial electrical parameters; The gain of the voltage to be measured is determined based on the resonant frequency ratio, the normalized frequency ratio, and the target quality factor. When the voltage gain under test meets the target voltage gain, the initial resonant inductance value, the optimized magnetizing inductance value, and the initial electrical parameters of the power switching device are determined as the target resonant parameters in the DC-DC converter that meet the target voltage gain.

[0086] Figure 5 This is a schematic diagram of the structure of the electronic device provided in the embodiment of the present invention, such as... Figure 5As shown, the electronic device may include: a processor 510, a communication interface 520, a memory 530, and a communication bus 540, wherein the processor 510, the communication interface 520, and the memory 530 communicate with each other through the communication bus 540. The processor 510 can call logic instructions in the memory 530 to execute a method for determining the resonant parameters of a DC-DC converter. This method includes: determining the initial electrical parameters of the power switching devices in the DC-DC converter based on preset electrical parameters of the DC-DC converter; determining the initial resonant inductance value of the resonant network in the DC-DC converter based on the initial electrical parameters and the preset electrical parameters; determining the optimized excitation inductance value corresponding to the resonant network based on the initial electrical parameters and the high-frequency resonant phase angle during the dead time; the optimized excitation inductance value satisfying the zero-voltage turn-on condition; and determining the target resonant parameters in the DC-DC converter that satisfy the target voltage gain based on the optimized excitation inductance value and the initial resonant inductance value.

[0087] Furthermore, the logical instructions in the aforementioned memory 530 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0088] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the method for determining the resonant parameters of a DC-DC converter provided by the above methods. The method includes: determining the initial electrical parameters of the power switching devices in the DC-DC converter based on preset electrical parameters of the DC-DC converter; determining the initial resonant inductance value of the resonant network in the DC-DC converter based on the initial electrical parameters and the preset electrical parameters; determining the optimized excitation inductance value corresponding to the resonant network based on the initial electrical parameters and the high-frequency resonant phase angle during the dead time; the optimized excitation inductance value satisfying the zero-voltage turn-on condition; and determining the target resonant parameters in the DC-DC converter that satisfy the target voltage gain based on the optimized excitation inductance value and the initial resonant inductance value.

[0089] In another aspect, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements a method for determining the resonant parameters of a DC-DC converter provided by the methods described above. This method includes: determining initial electrical parameters of power switching devices in the DC-DC converter based on preset electrical parameters of the DC-DC converter; determining an initial resonant inductance value of the resonant network in the DC-DC converter based on the initial electrical parameters and the preset electrical parameters; determining an optimized magnetizing inductance value corresponding to the resonant network based on the initial electrical parameters and the high-frequency resonant phase angle during the dead time; the optimized magnetizing inductance value satisfying a zero-voltage turn-on condition; and determining a target resonant parameter in the DC-DC converter that satisfies a target voltage gain based on the optimized magnetizing inductance value and the initial resonant inductance value.

[0090] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0091] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for determining the resonant parameters of a DC-DC converter, characterized in that, include: Based on the preset electrical parameters of the DC-DC converter, the initial electrical parameters of the power switching devices in the DC-DC converter are determined; Based on the initial electrical parameters and the preset electrical parameters, the initial resonant inductance value of the resonant network in the DC-DC converter is determined; Based on the initial electrical parameters and the high-frequency resonant phase angle during the dead time, the optimized excitation inductance value corresponding to the resonant network is determined. The optimized excitation inductance value satisfies the zero-voltage turn-on condition; Based on the optimized excitation inductance value and the initial resonant inductance value, the target resonant parameters that satisfy the target voltage gain in the DC-DC converter are determined.

2. The method for determining the resonant parameters of a DC-DC converter according to claim 1, characterized in that, The step of determining the optimized excitation inductance value corresponding to the resonant network based on the initial electrical parameters and the high-frequency resonant phase angle within the dead time includes: Based on the initial electrical parameters and the primary-side electrical parameters of the primary-side switching network in the DC-DC converter, the expression for the target magnetizing inductance is determined. Based on the high-frequency resonant phase angle and the target excitation inductance expression, an excitation inductance constraint model is constructed; the excitation inductance constraint model is used to characterize the excitation inductance range that satisfies the zero-voltage turn-on condition. Based on the excitation inductance constraint model, the optimal excitation inductance value that satisfies the zero-voltage turn-on condition in the resonant network is determined.

3. The method for determining the resonant parameters of a DC-DC converter according to claim 2, characterized in that, The construction of the excitation inductance constraint model based on the high-frequency resonant phase angle and the target excitation inductance expression includes: Based on the expression for the target excitation inductance, the partial derivative of the high-frequency resonant phase angle is obtained to get the maximum starting phase angle and the maximum ending phase angle. Based on the maximum starting phase angle and the maximum ending phase angle, the range of excitation inductance corresponding to the target excitation inductance expression is partitioned to obtain the excitation inductance constraint model.

4. The method for determining the resonant parameters of a DC-DC converter according to claim 2, characterized in that, The determination of the target magnetizing inductance expression based on the initial electrical parameters and the primary-side electrical parameters of the primary-side switching network in the DC-DC converter includes: Based on the initial electrical parameters and the primary-side electrical parameters of the primary-side switching network in the DC-DC converter, the junction capacitance voltage corresponding to the power switching device is determined; When the junction capacitance voltage is less than or equal to 0, determine the expression for the first magnetizing inductance; Based on the first excitation inductance expression, the target excitation inductance expression is determined.

5. The method for determining the resonant parameters of a DC-DC converter according to claim 1, characterized in that, Determining the initial resonant inductance value of the resonant network in the DC-DC converter based on the initial electrical parameters and the preset electrical parameters includes: The target quality factor is determined based on a preset correlation relationship and a preset resonant capacitor voltage; the preset correlation relationship is used to characterize the correlation between the quality factor and the voltage gain. Based on the target quality factor, the initial resonant inductance value of the resonant network in the DC-DC converter is determined.

6. The method for determining the resonant parameters of a DC-DC converter according to claim 5, characterized in that, The determination of the target resonant parameters in the DC-DC converter that satisfy the target voltage gain based on the optimized excitation inductance value and the initial resonant inductance value includes: Based on the optimized excitation inductance value and the initial resonant inductance value, the normalized frequency ratio is determined. The resonant frequency is determined based on the target quality factor, the initial resonant inductance value, and the preset electrical parameters. The resonant frequency ratio is determined based on the resonant frequency and the switching frequency in the initial electrical parameters; The gain of the voltage to be measured is determined based on the resonant frequency ratio, the normalized frequency ratio, and the target quality factor. When the voltage gain under test meets the target voltage gain, the initial resonant inductance value, the optimized magnetizing inductance value, and the initial electrical parameters of the power switching device are determined as the target resonant parameters in the DC-DC converter that meet the target voltage gain.

7. The method for determining the resonant parameters of a DC-DC converter according to any one of claims 1-6, characterized in that, The preset electrical parameters include input voltage, output voltage, input power, and equivalent load; the initial electrical parameters include the transformer turns ratio, switching frequency, and dead time.

8. A device for determining the resonant parameters of a DC-DC converter, characterized in that, include: The first determining module is used to determine the initial electrical parameters of the power switching devices in the DC-DC converter based on the preset electrical parameters of the DC-DC converter; The second determining module is used to determine the initial resonant inductance value of the resonant network in the DC-DC converter based on the initial electrical parameters and the preset electrical parameters. The third determining module is used to determine the optimized excitation inductance value corresponding to the resonant network based on the initial electrical parameters and the high-frequency resonant phase angle during the dead time. The optimized excitation inductance value satisfies the zero-voltage turn-on condition; The fourth determining module is used to determine the target resonant parameters in the DC-DC converter that satisfy the target voltage gain based on the optimized excitation inductance value and the initial resonant inductance value.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the method for determining the resonant parameters of the DC-DC converter as described in any one of claims 1 to 7.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the method for determining the resonant parameters of the DC-DC converter as described in any one of claims 1 to 7.

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