LLC half-bridge resonant converter parameter design method and related equipment

Abstract

The invention relates to an LLC half-bridge resonant converter parameter design method and related equipment. The method comprises the following steps: S1, respectively obtaining weight coefficients of resonant inductor current and resonant capacitor alternating-current voltage amplitudes of the converter and normalization results corresponding to the resonant inductor current and the resonant capacitor alternating-current voltage amplitudes, and constructing a preset single objective function according to the weight coefficients and the normalization results; wherein the sum of the weight coefficients of the amplitude of the resonant inductor current and the amplitude of the resonant capacitor AC voltage is 1; and S2, obtaining a performance index corresponding to the converter, and carrying out iterative calculation according to the performance index and the preset single objective function by taking the design parameter corresponding to the converter as a variable, so as to obtain a corresponding design parameter when the preset single objective function is the minimum value as a final design parameter of the converter. Converter parameter design difficulty can be reduced, and converter design efficiency can be improved.

Description

Technical Field

[0001] This invention relates to the field of converter design technology, and more specifically, to a parameter design method and related equipment for an LLC half-bridge resonant converter. Background Technology

[0002] like Figure 7 The LLC half-bridge resonant converter structure shown can simultaneously achieve zero-voltage switching (ZVS) of the primary MOSFET and zero-current switching (ZCS) of the secondary diode, reducing the turn-on losses of the primary MOSFET and the reverse recovery losses of the secondary diode, thus improving the converter's efficiency. It has been widely used in AC-DC power supplies, battery chargers, and other fields. Whether the LLC half-bridge resonant converter can achieve ZVS of the primary MOSFET and ZCS of the secondary diode depends on designing reasonable circuit parameters (magnetizing inductance). Resonant capacitor and resonant inductor Therefore, how to select parameters simply and efficiently has become an important direction in this field (DC / DC converters). Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a parameter design method and related equipment for an LLC half-bridge resonant converter, addressing the aforementioned technical deficiencies of the prior art.

[0004] The technical solution adopted by this invention to solve its technical problem is: to construct a parameter design method for an LLC half-bridge resonant converter, the method comprising the following steps: S1. Obtain the weighting coefficients of the AC voltage amplitudes of the resonant inductor current and the resonant capacitor of the converter, and the normalization results corresponding to the AC voltage amplitudes of the resonant inductor current and the resonant capacitor, respectively, so as to construct a preset single objective function based on the weighting coefficients and the normalization results; wherein, the sum of the weighting coefficients of the AC voltage amplitudes of the resonant inductor current and the resonant capacitor is 1. S2. Obtain the performance index corresponding to the converter, and perform iterative calculation based on the performance index and the preset single objective function using the design parameters corresponding to the converter as variables, so as to obtain the design parameters corresponding to the minimum value of the preset single objective function as the final design parameters of the converter.

[0005] Preferably, in one embodiment of the LLC half-bridge resonant converter parameter design method of the present invention, in step S1, the preset single objective function includes: ； wherein, α is a weight coefficient of the resonant inductor current, 1- α is a weight coefficient of the resonant capacitor AC voltage amplitude, and satisfies 0 α <1; is 0 or 1; is a normalized resonant inductor current, is a normalized resonant capacitor AC voltage amplitude; and ; wherein, is the resonant inductor current, is the resonant capacitor AC voltage amplitude, is a maximum value of the resonant inductor current, is a minimum value of the resonant inductor current, is a maximum value of the resonant capacitor AC voltage amplitude, is a minimum value of the resonant capacitor AC voltage amplitude.

[0006] Preferably, in the LLC half-bridge resonant converter parameter design method according to the present application, in step S2, the performance index corresponding to the converter is obtained, and the design parameters corresponding to the converter are taken as variables to perform iterative calculation according to the performance index and the preset single-objective function, which includes: S21, the values of the excitation inductance, the resonant inductance and the resonant capacitance of the converter are iteratively calculated according to a preset algorithm, so as to obtain the resonant frequency, the quality factor, the quality factor under overload and the maximum allowable quality factor corresponding to the converter, and the minimum operating frequency of the converter according to the values of the excitation inductance, the resonant inductance and the resonant capacitance in the iteration process; S22, the values of the excitation inductance, the resonant inductance and the resonant capacitance in the iteration process are constrained based on a first constraint condition corresponding to the quality factor, the overload quality factor, the maximum allowable quality factor and the ratio of the excitation inductance to the resonant inductance, a second constraint condition corresponding to the excitation inductance and a third preset condition corresponding to the resonant capacitance, and the values of are obtained according to the constraint results of all the constraint conditions; S23, the resonant inductor current and the resonant capacitor AC voltage amplitude of the converter are obtained according to the iteration process, and the values of the excitation inductance, the resonant inductance and the resonant capacitance corresponding to the minimum value of the preset single-objective function are taken as the design parameters of the converter.

[0007] Preferably, in the LLC half-bridge resonant converter parameter design method according to the present application, the method further includes: S211, obtaining the turns ratio of the transformer, to obtain the maximum gain of the transformer according to the turns ratio of the transformer, the forward conduction voltage drop of the secondary side diode, the maximum output voltage and the minimum input voltage, and obtain the minimum gain of the transformer according to the turns ratio of the transformer, the forward conduction voltage drop of the secondary side diode, the minimum output voltage and the maximum input voltage; S212, obtaining the rated primary side equivalent resistance of the transformer according to the turns ratio of the transformer and the rated output voltage, and obtaining the overload primary side equivalent resistance of the transformer according to the turns ratio of the transformer, the rated output current and the power overload coefficient; S213, obtaining the corresponding quality factor, overload quality factor and allowable maximum quality factor of the transformer according to the rated primary side equivalent resistance, the overload primary side equivalent resistance, the maximum gain, the excitation inductance, the resonance inductance and the resonance capacitance.

[0008] Preferably, in the embodiment of the LLC half-bridge resonant converter parameter design method of the application, the method further comprises: obtaining the minimum operating frequency of the transformer according to the maximum gain and the resonance frequency corresponding to the transformer.

[0009] Preferably, in the embodiment of the LLC half-bridge resonant converter parameter design method of the application, the first constraint condition comprises: , and ; wherein, Q is the overload quality factor of the transformer, Q is the allowable maximum quality factor of the transformer, is the ratio of the value of the excitation inductance to the resonance inductance.

[0010] Preferably, in the embodiment of the LLC half-bridge resonant converter parameter design method of the application, the second constraint condition comprises: , and ; wherein, is the excitation inductance, is the dead time of the upper and lower tube conduction in the transformer, is the source-drain capacitance of the switch tube in the transformer, is the series resonance frequency of the transformer, is the calculated value of the series resonance frequency of the transformer in the iteration process.

[0011] Preferably, in the embodiment of the LLC half-bridge resonant converter parameter design method of the application, the third constraint condition comprises: ; wherein, is the resonant capacitance, is the rated output voltage of the converter, is the rated output current of the converter, is the minimum operating frequency calculation value of the converter, is the estimated conversion efficiency of the converter, is the maximum input voltage of the converter.

[0012] The application also provides an electronic device comprising a memory and a processor; The memory is configured to store a computer program; The processor is configured to execute the computer program to implement the method as described above.

[0013] The application also provides a computer storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to implement the method as described above.

[0014] The LLC half-bridge resonant converter parameter design method and related device of the application have the following beneficial effects: the difficulty of converter parameter design is reduced, and the design efficiency of the converter is improved. BRIEF DESCRIPTION OF DRAWINGS

[0015] The application will be further described below in conjunction with the drawings and embodiments, wherein: Figure 1 is a program flow chart of an embodiment of the LLC half-bridge resonant converter parameter design method of the application; Figure 2 is a program flow chart of another embodiment of the LLC half-bridge resonant converter parameter design method of the application; Figure 3 is a program flow chart of still another embodiment of the LLC half-bridge resonant converter parameter design method of the application; Figure 4 is a simulation schematic diagram of the LLC half-bridge resonant converter of an embodiment of the application; Figure 5 is the Q2 waveform in the LLC half-bridge resonant converter of an embodiment of the application; and waveforms; Figure 6 is the D2 waveform in the LLC half-bridge resonant converter of an embodiment of the application; and waveforms; Figure 7 is a current circuit diagram of the LLC half-bridge resonant converter. DETAILED DESCRIPTION

[0016] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0017] like Figure 1 The figure shows an embodiment of the LLC half-bridge resonant converter parameter design method of the present invention. Figure 1 In an embodiment of the LLC half-bridge resonant converter parameter design method of the present invention, the method includes: S1, obtaining the weighting coefficients of the resonant inductor current and the AC voltage amplitude of the resonant capacitor, and the normalized results corresponding to the resonant inductor current and the AC voltage amplitude of the resonant capacitor, respectively, to construct a preset single objective function based on the weighting coefficients and the normalized results; wherein, the sum of the weighting coefficients of the resonant inductor current and the AC voltage amplitude of the resonant capacitor is 1; S2, obtaining the performance index corresponding to the converter, and using the design parameters of the converter as variables, performing iterative calculations based on the performance index and the preset single objective function, to obtain the design parameters corresponding to the minimum value of the preset single objective function as the final design parameters of the converter.

[0018] Based on step S1, when the converter is operating, when the converter's magnetizing inductance... Resonant inductor Full load, i.e., rated primary-side equivalent resistance Equivalent input voltage of LLC circuit If the resonant capacitance is increased while keeping the capacitance constant... The impedance of the resonant capacitor decreases, thereby causing the resonant inductor current to decrease. Increase; resonant inductor current Increasing the capacitance will inevitably increase the conduction loss of the MOSFET; however, on the other hand, during the off period of the upper MOSFET Q1, the resonant capacitance... Acting as a DC power source, the stored energy must be sufficient to power the load during the conduction of the lower transistor; due to the total energy transferred... The output power remains unchanged, so when the resonant capacitor... When it increases, the formula The resonant capacitor is obtained. The AC voltage amplitude is the AC voltage amplitude of the resonant capacitor. Decrease. Conversely, increase the resonant capacitance. Reduce the resonant inductor current Reduce, resonant capacitance The AC voltage amplitude is the AC voltage amplitude of the resonant capacitor. Increase. In specific embodiments, unless otherwise specified, the unit for capacitance is usually nF, the unit for inductance is usually uH, the unit for voltage is usually V, the unit for current is usually A, the unit for resistance is usually Ω, and the unit for frequency is usually Hz.

[0019] When the converter is working, when the resonant inductance of the converter... Resonant capacitor Full load, i.e., rated primary-side equivalent resistance Equivalent input voltage of LLC circuit If the excitation inductance is increased while keeping the current constant... This results in the current flowing through the magnetizing inductor. Reduce; resonant inductor current Reduced, due to the total energy transferred With the output power remaining constant, the resonant capacitor is obtained. The AC voltage amplitude is the AC voltage amplitude of the resonant capacitor. The current increases. Conversely, the current flowing through the magnetizing inductor decreases. Reduce the resonant inductor current Increase, resonant capacitance The AC voltage amplitude is the AC voltage amplitude of the resonant capacitor. Decrease.

[0020] When the converter is operating, when the converter's magnetizing inductance... Resonant capacitor Full load, i.e., rated primary-side equivalent resistance Equivalent input voltage of LLC circuit If the resonant inductance is increased while keeping the value unchanged... This leads to the resonant inductor current. Reduce, and obtain the resonant capacitance. The AC voltage amplitude is the AC voltage amplitude of the resonant capacitor. Increase. Conversely, increase the resonant inductor current. resonant capacitor The AC voltage amplitude is the AC voltage amplitude of the resonant capacitor. Decrease.

[0021] Therefore, based on the converter's operational requirements, weighting coefficients are set for the resonant inductor current and the AC voltage amplitude of the resonant capacitor during converter operation. Simultaneously, the weighting coefficients for the resonant inductor current and the AC voltage amplitude of the resonant capacitor are normalized to construct a preset single-objective function. Subsequent processes are then executed based on this single-objective function.

[0022] Based on step S2, when designing a converter, it is generally understood that the performance indicators that the converter needs to meet are known. The purpose of obtaining the converter's design parameters is to ensure that the converter is set according to these design parameters so that it meets the required performance indicators. Depending on the application requirements of the converter, common performance indicators include, but are not limited to, its corresponding minimum input voltage. Maximum input voltage Rated input voltage Rated (also corresponding to full load) output voltage Maximum output voltage Minimum output voltage Rated output current Rated output power Maximum AC voltage amplitude of resonant capacitor Minimum AC voltage amplitude of resonant capacitor Maximum value of resonant inductor current Minimum value of resonant inductor current Gain overload factor Power overload factor Load regulation rate Estimated conversion efficiency η Series resonant frequency (Values ​​can be determined based on experience), minimum operating frequency The source-drain capacitance of the MOSFET Dead time of conduction between upper and lower tubes .

[0023] The preset single-objective function is iteratively calculated based on performance indicators. During the iterative calculation process, the design parameters are iterated to obtain the satisfactory design parameters based on the results of the preset single-objective function. The maximum number of iterations can be set. The optimal design parameters are obtained through iterative calculations within a finite number of iterations. This can be understood as the process of obtaining the converter's design parameters actually involving a preset number of iterative calculations (maximum number of iterations). Obtain the excitation inductance of the converter. Resonant capacitor and resonant inductor The process of finding the optimal value.

[0024] In one embodiment, in step S1, a preset single-objective function is constructed based on weighting coefficients, with the amplitudes of the resonant inductor current and the resonant capacitor AC voltage as parameters, including: ; Where α is the weighting coefficient of the resonant inductor current, and 1-α is the weighting coefficient of the AC voltage amplitude of the resonant capacitor, and 0 < α < 1; These are constraints, set to 0 or 1 depending on whether the constraints are satisfied. For the normalized resonant inductor current, The normalized AC voltage amplitude of the resonant capacitor can be calculated using the following formula: ; in, For the resonant inductor current, The amplitude of the AC voltage of the resonant capacitor. This represents the maximum value of the resonant inductor current. This is the minimum value of the resonant inductor current. This represents the maximum amplitude of the AC voltage across the resonant capacitor. This represents the minimum value of the AC voltage amplitude of the resonant capacitor.

[0025] Specifically, α is the weighting coefficient for the resonant inductor current, ranging from 0 to 1. α can be adjusted according to the performance parameter requirements of the converter. For example, if the application scenario of the converter requires... and Taking the same considerations, we can set α=0.5. The calculation of the converter's design parameters based on the preset single-objective function constructed using this value will simultaneously take into account... and Requirements; such as the application scenarios of the converter require The considerations outweigh the considerations for Considering this, α can be set to 0.3, and the design parameters of the converter can be calculated and solved using a preset single-objective function constructed based on this value. The considerations outweigh the considerations for Considerations, such as prioritizing Requirements; such as the application scenarios of the converter requiring... The considerations outweigh the considerations for Considering this, α can be set to 0.7, and the design parameters of the converter can be calculated and solved using a preset single-objective function constructed based on this value. The considerations outweigh the considerations for Considerations, such as prioritizing The requirements. Among them The constraint parameter is 0 if all constraints are satisfied, and 1 otherwise.

[0026] The following formula can also be obtained by transforming the preset single-objective function: .

[0027] This means that during parameter optimization, calculations can be performed based on the above function, and the final design parameters can be obtained from the function results for converter design.

[0028] In one embodiment, such as Figure 2As shown, in step S2, the performance indicators corresponding to the converter are obtained, and iterative calculations are performed based on the performance indicators and a preset single objective function using the design parameters corresponding to the converter as variables. This includes: S21, iterative calculations are performed on the values ​​of the excitation inductance, resonant inductance, and resonant capacitor of the converter according to a preset algorithm, so that the calculated value of the resonant frequency of the converter, as well as the quality factor, overload quality factor, and maximum allowable quality factor, and the calculated value of the minimum operating frequency of the converter are obtained based on the performance indicators and the values ​​of the excitation inductance, resonant inductance, and resonant capacitor during the iteration process; S22, the values ​​of the excitation inductance, resonant inductance, and resonant capacitor are constrained based on the quality factor, overload quality factor, maximum allowable quality factor, the first constraint condition corresponding to the excitation inductance and resonant inductance, the second constraint condition corresponding to the excitation inductance, and the third preset condition corresponding to the resonant capacitor during the iteration process, and the results of all constraint conditions are used to obtain... The values ​​of S23 are obtained according to the iteration process. The values ​​of the resonant inductor current and resonant capacitor AC voltage amplitude of the converter are obtained. The values ​​of the excitation inductor, resonant inductor and resonant capacitor corresponding to the minimum value of the preset single objective function are obtained as the design parameters of the converter.

[0029] Specifically, in the iterative calculation process, iterative algorithms such as particle swarm optimization can be used to calculate the excitation inductance of the converter. Resonant capacitor and resonant inductor The design parameters are calculated iteratively. In each iteration, the values ​​can be determined based on the formula. Get the corresponding Based on experience, it can be limited Values ​​are taken in the range of 2 to 9, according to... The value of the magnetizing inductor is required. and resonant inductor The values ​​of are constrained. And according to the formula... get Calculated value According to For resonant capacitors and resonant inductor The values ​​of the parameters are constrained. It can be understood that in this embodiment, the performance index limits the parameters, and the calculated value of the performance index can be obtained based on the actual value, ultimately serving as a judgment criterion or a constraint condition for its value.

[0030] The quality factor of the converter is calculated according to the following formulas. Overload quality factors and maximum quality factor Acquisition; ; wherein, is the maximum gain of the transformer, is the minimum gain of the transformer, is the rated primary equivalent resistance of the transformer, is the overload primary equivalent resistance of the transformer, and each of the above parameters can be directly or indirectly obtained according to the performance index requirements of the transformer. The quality factor , the overload quality factor and the maximum quality factor corresponding to the constraint conditions are used to constrain the values of the resonant capacitance and the resonant inductance . That is, in the iterative calculation process, the values of the resonant capacitance and the resonant inductance are adjusted so that the calculated quality factor , the overload quality factor and the maximum quality factor satisfy the requirements.

[0031] In a specific embodiment, the first constraint condition constructed can be, , and . According to the above calculation process, the values of the resonant capacitance and the resonant inductance are constrained according to the constraint condition.

[0032] In a specific embodiment, the value of the magnetizing inductance can be directly constrained, that is, a second constraint condition is constructed, which can be specifically, wherein, is the dead time of the upper and lower tube conduction in the transformer, generally 100 ns to 300 ns, is the source-drain capacitance of the switch tube in the transformer, generally 50 pF to 100 pF, is the calculated value of the series resonant frequency of the transformer in the iteration process, which satisfies . That is, the calculated value of the series resonant frequency of the transformer in the iteration process needs to be controlled within the range of the performance index requirements. When both of the two switch tubes in the transformer are turned off, in order to satisfy that the output capacitance of the two switch tubes completes a charge and discharge within the dead time , the value of the magnetizing inductance is constrained through the above condition.

[0033] In a specific embodiment, the value of the resonant capacitance can be directly constrained, that is, a third constraint condition is constructed, which can be specifically, ; wherein, is the rated output voltage of the converter, is the rated output current of the converter, is the estimated conversion efficiency of the converter, is the maximum input voltage of the converter, is the minimum operating frequency of the converter. The minimum operating frequency can be calculated according to the formula , i.e., the minimum operating frequency can be calculated according to the calculated value of the series resonance frequency and .

[0034] i.e., when the upper MOS is off, the capacitor acts as a DC source; The stored energy needs to support the lower Q2 during the on period, and provide energy for the load, so the minimum value of can be obtained based on the third constraint condition.

[0035] Since the resonance capacitor is related to the frequency, when the converter is working at , it needs to obtain the parameters by whether all the above constraints are met; if any condition is not met, .

[0036] In the above iteration process, the resonance inductor current obtained in each iteration can be calculated according to the following formula.

[0037] ; wherein, is the , is the actual minimum operating frequency of the converter.

[0038] The resonance capacitor AC voltage amplitude obtained in each iteration is calculated according to the following formula; ; After the obtained resonance inductor current and resonance capacitor AC voltage amplitude are normalized, the single objective function is calculated. The process of calculating the function result by the single objective function is that the values of the excitation inductance, resonance inductance and resonance capacitor corresponding to the minimum calculation result are the design parameters of the converter.

[0039] In an embodiment, as Figure 3As shown, the LLC half-bridge resonant converter parameter design method of the application further includes: S211, obtaining the turns ratio of the converter, so as to obtain the maximum gain of the converter according to the turns ratio of the converter, the forward conduction voltage drop of the secondary side diode, the maximum output voltage and the minimum input voltage, and obtain the minimum gain of the converter according to the turns ratio of the converter, the forward conduction voltage drop of the secondary side diode, the minimum output voltage and the maximum input voltage; S212, obtaining the rated primary side equivalent resistance of the converter according to the turns ratio of the converter and the rated output voltage, and obtaining the overload primary side equivalent resistance of the converter according to the turns ratio of the converter, the rated output current and the power overload coefficient; S213, obtaining the corresponding quality factor, the overload quality factor and the allowable maximum quality factor of the converter according to the rated primary side equivalent resistance, the overload primary side equivalent resistance, the maximum gain, the excitation inductance, the resonant inductance and the resonant capacitance.

[0040] Specifically, the turns ratio of the converter can be calculated according to the formula , and the values of and are set.

[0041] Among them, the specific performance indicators are as shown above, wherein, is the forward conduction voltage of the secondary side output rectifier diode, i.e. the forward conduction voltage drop of the secondary side diode; the empirical value is 0.7V.

[0042] At the same time, the rated primary side equivalent resistance and the overload primary side equivalent resistance of the converter corresponding to the performance index requirements of the converter are calculated, and the specific calculation process can be specifically calculated according to the following formula.

[0043] Then, the quality factor , the overload quality factor and the maximum quality factor of the converter corresponding to the performance index requirements of the converter can be obtained according to the formula .

[0044] In the iteration process, the excitation inductance , the resonant capacitance and the resonant inductance ​​The initial value of the excitation inductance can be in the range of 0-1000 uH, the resonance capacitance in the range of 0-1000 nF, and the resonance inductance in the range of 0-1000 uH. In the first iteration, they are randomly selected within the value range, without fixed values.

[0045] In a specific embodiment, the performance indicators of the converter meet the following requirements: minimum input voltage , maximum input voltage , rated input voltage , rated output voltage , maximum output voltage , minimum output voltage , rated output current , rated output power , maximum resonance capacitance AC voltage amplitude , minimum resonance capacitance AC voltage amplitude , maximum resonance inductance current , minimum resonance inductance current , gain overload coefficient , power overload coefficient , load regulation rate , estimated conversion efficiency η = 0.96, calculated value of series resonance frequency 100 kHz ± 20%, minimum operating frequency , source-drain capacitance of switch MOS , dead time of upper and lower tube conduction , and set alpha = 0.5 .

[0046] Finally, based on the preset single-objective function, the iteration calculation is performed to obtain the value of the excitation inductance 175.8597 uH, the resonance inductance 31.0268 uH, and the resonance capacitance 74.7177 nF. Correspondingly, the value of 4.4013 A, 131.2131 V.

[0047] To further verify the accuracy of the results, parameter simulation is performed under PSIM software, such as Figure 4 the simulation schematic diagram of the LLC half-bridge resonant converter, such as Figure 5 the and waveforms of Q2 in the half-bridge resonant converter, such as Figure 6 the and Waveform.

[0048] like Figure 5 As shown, when Q2's After the voltage drops to 0, and a dead time of 100ns passes, Q2's... The voltage only begins to rise before Q2 begins to conduct, thus achieving ZVS (zero voltage turn-on) of the primary-side MOS-Q2.

[0049] like Figure 6 As shown, when the current flowing through D2 When the voltage drops to 0, the voltage across D2 begins to change from negative to positive, meaning D2 changes from the off state to the on state, achieving the ZCS zero-current turn-off of the secondary diode.

[0050] Furthermore, an electronic device according to the present invention may further include a memory and a processor; the memory is used to store a computer program; the processor is used to execute the computer program to implement the above-described method. Specifically, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, when the computer program is downloaded, installed, and executed by an electronic device, it performs the functions defined in the methods of the embodiments of the present invention. The electronic device in the present invention may be a terminal such as a laptop, desktop computer, tablet computer, or smartphone, or it may be a server.

[0051] In addition, the computer storage medium of the present application has a computer program stored thereon, and the computer program is executed by a processor to implement the method of any one of the above. Specifically, it should be noted that the computer readable medium of the present application can be a computer readable signal medium or a computer readable storage medium or any combination of the two. The computer readable storage medium may, for example, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or component, or any combination thereof. More specific examples of computer readable storage media can include, but are not limited to, an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, the computer readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, device or component. In the present application, the computer readable signal medium can include a data signal carried in a baseband or as part of a carrier wave, which carries computer readable program code. Such a propagated data signal can take many forms, including but not limited to an electromagnetic signal, an optical signal, or any suitable combination thereof. The computer readable signal medium can also be any computer readable medium other than the computer readable storage medium, which can send, propagate or transmit a program for use by or in conjunction with an instruction execution system, device or component. The program code contained in the computer readable medium can be transmitted by any suitable medium, including but not limited to electrical wires, optical cables, RF (radio frequency), etc., or any suitable combination thereof.

[0052] The above computer readable medium can be contained in the above electronic device, or can exist separately and not be assembled into the electronic device.

[0053] It can be understood that the above embodiments only express the preferred embodiments of the present application, which are described in detail and in detail, but cannot be understood as a limitation on the scope of the patent of the present application; it should be noted that for ordinary skilled in the art, the above technical features can be freely combined without departing from the concept of the present application, and some modifications and improvements can be made, which are within the scope of protection of the present application; therefore, any equivalent transformation and modification within the scope of the claims of the present application shall be within the scope of the claims of the present application.

Claims

1. A method of LLC half-bridge resonant converter parameter design, characterized in that, The method comprises the following steps: S1, respectively acquiring the weight coefficients of the resonant inductor current and the resonant capacitor AC voltage amplitude of the converter and the normalized results corresponding to the resonant inductor current and the resonant capacitor AC voltage amplitude, and constructing a preset single objective function according to the weight coefficients and the normalized results; wherein the sum of the weight coefficients of the resonant inductor current and the resonant capacitor AC voltage amplitude is 1; S2, acquiring the performance index corresponding to the converter, and performing iterative calculation according to the performance index and the preset single objective function with the design parameters corresponding to the converter as variables, so that the design parameters corresponding to the minimum value of the preset single objective function are the final design parameters of the converter.

2. The LLC half-bridge resonant converter parameter design method of claim 1, wherein, In the step S1, the preset single objective function comprises: ； wherein, α is a weight coefficient of the resonant inductance current, 1- α is a weight coefficient of the resonant capacitance AC voltage amplitude, and satisfies 0 < a < 1; α < 1; is 0 or 1; is a normalized resonant inductance current, is a normalized resonant capacitance AC voltage amplitude; and ； wherein, is the resonant inductor current, is the resonant capacitor AC voltage amplitude, is the maximum value of the resonant inductor current, is the minimum value of the resonant inductor current, is the maximum value of the resonant capacitor AC voltage amplitude, is the minimum value of the resonant capacitor AC voltage amplitude.

3. The LLC half-bridge resonant converter parameter design method of claim 2, wherein, In step S2, the performance index corresponding to the converter is acquired, and iterative calculation is performed according to the performance index and the preset single objective function with the design parameters corresponding to the converter as variables, comprising: S21, performing iterative calculation on the values of the excitation inductance, resonant inductance and resonant capacitance of the converter according to a preset algorithm, so as to acquire the resonant frequency calculation value of the converter, the quality factor, the overload quality factor and the maximum allowable quality factor of the converter, and the minimum working frequency calculation value of the converter in the iterative process according to the performance index and the values of the excitation inductance, resonant inductance and resonant capacitance; S22, based on the quality factor, overload quality factor, the maximum quality factor allowed, the first constraint condition corresponding to the excitation inductance and the resonance inductance, the second constraint condition corresponding to the excitation inductance and the third preset condition corresponding to the resonance capacitance, the values of the excitation inductance, the resonance inductance and the resonance capacitance in the iteration process are constrained, and the values of the excitation inductance, the resonance inductance and the resonance capacitance are obtained according to the constraint results of all constraint conditions. ​ S23, acquiring the resonant inductor current and the resonant capacitor AC voltage amplitude of the converter according to the iterative process, and acquiring the values of the excitation inductance, resonant inductance and resonant capacitance corresponding to the minimum value of the preset single objective function as the design parameters of the converter.

4. The LLC half-bridge resonant converter parameter design method of claim 3, wherein, The method further comprises: S211, acquiring the turns ratio of the converter, so as to acquire the maximum gain of the converter according to the turns ratio of the converter, the forward conduction voltage drop of the secondary side diode, the maximum output voltage and the minimum input voltage, and acquire the minimum gain of the converter according to the turns ratio of the converter, the forward conduction voltage drop of the secondary side diode, the minimum output voltage and the maximum input voltage; S212, acquiring the rated primary side equivalent resistance of the converter according to the turns ratio of the converter and the rated output voltage, and acquiring the overload primary side equivalent resistance of the converter according to the turns ratio of the converter, the rated output current and the power overload coefficient; S213, acquiring the quality factor, the overload quality factor and the maximum allowable quality factor corresponding to the converter according to the rated primary side equivalent resistance, the overload primary side equivalent resistance, the maximum gain, the values of the excitation inductance, resonant inductance and resonant capacitance.

5. The LLC half-bridge resonant converter parameter design method of claim 4, wherein, The method further comprises: Acquiring the minimum working frequency of the converter according to the maximum gain and the resonant frequency corresponding to the converter.

6. The LLC half bridge resonant converter parameter design method of claim 3, wherein, The first constraint condition includes: , and ; wherein is an overload quality factor of the converter, is an allowed maximum quality factor of the converter, is a ratio of the value of the excitation inductance to the value of the resonance inductance.

7. The LLC half bridge resonant converter parameter design method of claim 3, wherein, The second constraint condition comprises: , and ; wherein, is the magnetizing inductance of the transformer, is the dead time of the upper and lower transistor conduction in the transformer, is the source-drain capacitance of the switching transistor in the transformer, is the series resonant frequency of the transformer, is the calculated value of the series resonant frequency of the transformer in the iteration process.

8. The LLC half-bridge resonant converter parameter design method of claim 7, wherein, The third constraint condition comprises: ； wherein is the resonant capacitance, is the nominal output voltage of the converter, is the nominal output current of the converter, is the minimum operating frequency value of the converter, is the estimated conversion efficiency of the converter, is the maximum input voltage of the converter.

9. An electronic device, comprising: comprising a memory and a processor; The memory is used to store a computer program; The processor is used to execute the computer program to realize the method according to any one of claims 1 to 8.

10. A computer storage medium having stored thereon a computer program, characterized in that The computer program, which is executed by a processor, implements the method as claimed in any of claims 1 to 8.

Images