Key parameter design optimization method for series resonance type direct-current converter

Abstract

The invention discloses a series resonance type direct current converter key parameter design optimization method, which specifically comprises the following steps: S1, selecting and designing a resonant frequency point according to a power level, the relationship between the resonant frequency point and resonant capacitance and inductance being # imgabs0 # S2, determining the lower limit of the value Cr of the resonant capacitance by drawing up the frequency, and then multiplying the value by Y times; the invention relates to the technical field of research and development of power electronic equipment. According to the key parameter design optimization method for the series resonant DC converter, the resonant capacitance Cr during iteration is limited to aF, so that the temperature rise of the resonant inductor Lr can be effectively suppressed, a certain contribution is made to the improvement of the overall efficiency of the converter, the voltage gain range of an isolated DC conversion circuit is wide, the efficiency of the converter is higher, and the reliability of the converter is improved. According to the invention, many problems existing in a high-power application scene can be effectively avoided, the temperature rise of the resonant inductor under a severe working condition is reduced, the direct-current conversion efficiency of the direct-current converter is improved, the reliability is improved, and the operation performance is good.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronic equipment research and development, and in particular to a method for optimizing the design of key parameters of a series resonant DC converter. Background Art

[0002] Power electronics technology is widely used in industry, transportation, medical treatment, IT, communication, national defense and daily life. Power electronics devices based on power electronics technology have also developed rapidly. Power electronics devices are mainly divided into DC power supply, reactive power supply and transmission device. DC power supply is one of the important branches of power electronics devices and is widely used in various fields of national production. At present, the efficient and high-power DC power supply system is mainly composed of DC-DC converter based on power electronics switching technology. The converter converts the information sent by the source according to a certain purpose. The matrix converter is a new type of AC-AC power converter. Compared with the traditional converter, it has the following advantages: no intermediate DC energy storage link is required; it can operate in four quadrants; it has excellent input current waveform and output voltage waveform; the power factor can be freely controlled. The matrix converter has become one of the hot spots in the research of power electronics technology and has broad application prospects. The rationality of the resonant element parameter design method determines the performance of the series resonant DC converter. When applied to engineering practice, it is a multi-objective optimization problem. The parameter resonant capacitor C is matched with the designed frequency. r value and resonant inductance L r When calculating the value, the voltage stress of the resonant capacitor cannot be too large. Excessive voltage stress of the resonant capacitor will endanger the safety and reliability of the system.

[0003] At present, the parameter design methods for series resonant DC converters are mostly used in low-power scenarios. When the traditional conventional parameter calculation method is applied to high-power scenarios, the reliability is low. The reason for its low reliability is that the resonant inductor L under high power r The heat generation is extremely serious. The temperature rises during operation and the temperature rises quickly, which increases the loss of the series resonant DC converter and makes it impossible to operate reliably and stably for a long time. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention provides a method for optimizing the design of key parameters of a series resonant DC converter, which solves the problems mentioned in the above background technology.

[0005] To achieve the above objectives, the present invention is implemented by the following technical solutions: A method for optimizing the design of key parameters of a series resonant DC converter, specifically comprising the following steps:

[0006] S1. Select the design resonant frequency point according to the power level. The relationship between the resonant frequency point and the resonant capacitance and inductance is:

[0007] S2. Determine the resonant capacitance C by setting the frequency r After reaching the lower limit of the value, multiply the value by Y times;

[0008] S3. Substitute twice the lower limit of the resonant capacitance into the relationship between the resonant frequency, resonant capacitance and inductance to obtain the resonant inductance L. r value;

[0009] S4, the resonant inductor L r The temperature rise is calculated based on the value, and the output is determined based on whether the temperature rise of the resonant inductor is lower than 70°C.

[0010] S5, if in the resonant inductor L r If the judgment condition is not met under the value, the resonant capacitance value is reduced by 0.1aF, and step 3 is repeated, and the cycle is repeated until the judgment requirement of "Is the temperature rise of the resonant inductor lower than 70°C?" is met;

[0011] S6. If there is no solution after iteration, exit the loop and start a new loop: reduce the proposed frequency by 500 Hz and repeat steps 3, 4, and 5.

[0012] Preferably, in said S1, wherein f r is the resonant frequency, L r is the resonant inductor, C r is the resonant capacitor.

[0013] Preferably, in S1, a large resonant capacitance value C that is suitable for the power level and the design frequency is selected through a large number of experiments and simulations. r , substitute into the resonant frequency calculation formula Corresponding to the frequency design requirements, the resonant inductance L is obtained by reverse calculation r , the resonant inductance L r The corresponding power level is used to calculate the temperature rise and determine whether it meets the design requirements.

[0014] Preferably, in S2, when starting the calculation, a larger resonant capacitor C needs to be selected. r The value is multiplied by two times aF, and the resonant inductance value L is obtained by the resonant frequency calculation formula r .

[0015] Preferably, in S4, the temperature rise calculation is performed by using the resonant inductor L at a specific design power level. r Calculate the temperature rise of the current.

[0016] Preferably, in S4, when the design requirements are not met, the resonant capacitance is reduced and the resonant inductance is increased to keep the resonant frequency unchanged, and then the temperature rise calculation is performed until the design requirements are met, and the resonant inductance L is output. r, Capacitance C r value.

[0017] Preferably, in S5, after outputting the result, C r It must not be less than aF. If the temperature rise requirement is still not met after iteration to aF, the overall DC converter design frequency should be reduced, and the resonant capacitor C should be reduced each time. r The value is reduced by 0.1aF each time during the iteration process. The frequency reduction step after the temperature rise requirement is not met is 500Hz for each iteration.

[0018] Beneficial Effects

[0019] The present invention provides a method for optimizing the design of key parameters of a series resonant DC converter. Compared with the prior art, the method has the following beneficial effects:

[0020] The key parameter design optimization method of the series resonant DC converter specifically includes the following steps: S1, selecting a design resonant frequency point according to the power level, and the relationship between the resonant frequency point and the resonant capacitance and inductance is: S2. Determine the resonant capacitance C by setting the frequency r After finding the lower limit of the value, multiply the value by Y times; S3, substitute twice the lower limit of the resonant capacitance value into the relationship between the resonant frequency and the resonant capacitance and inductance to obtain the resonant inductance L r value; S4, the resonant inductor L r The temperature rise is calculated based on the value, and the output is determined based on the judgment condition "Is the temperature rise of the resonant inductor lower than 70°C?"; S5, if the resonant inductor L r If the judgment condition is not met under the value, the resonant capacitance value is reduced by 0.1aF, and step 3 is repeated, and the cycle is repeated until the judgment requirement of "Is the temperature rise of the resonant inductor lower than 70°C?" is met; S6, if there is no solution in the iteration, jump out of the loop and start a new loop: reduce the proposed frequency by 500Hz and repeat steps 3, 4, and 5; by changing the resonant capacitance C during the iteration r Limiting to aF can not only effectively suppress the resonant inductance L r Temperature rise also contributes to the overall efficiency improvement of the converter. The isolated DC conversion circuit has a wide voltage gain range and a higher converter efficiency. It can effectively avoid many problems existing in high-power application scenarios, reduce the temperature rise of the resonant inductor under harsh working conditions, improve the DC conversion efficiency of the DC converter, increase reliability, and have good operating performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a flow chart of the resonance combination parameter calculation of the present invention. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] See also Figure 1 The present invention provides a technical solution: a method for optimizing the design of key parameters of a series resonant DC converter, which specifically includes the following steps:

[0024] S1. Select the design resonant frequency point according to the power level. The relationship between the resonant frequency point and the resonant capacitance and inductance is:

[0025] S2. Determine the resonant capacitance C by setting the frequency r After reaching the lower limit of the value, multiply the value by Y times;

[0026] S3. Substitute twice the lower limit of the resonant capacitance into the relationship between the resonant frequency, resonant capacitance and inductance to obtain the resonant inductance L. r value;

[0027] S4, the resonant inductor L r The temperature rise is calculated based on the value, and the output is determined based on whether the temperature rise of the resonant inductor is lower than 70°C.

[0028] S5, if in the resonant inductor L r If the judgment condition is not met under the value, the resonant capacitance value is reduced by 0.1aF, and step 3 is repeated, and the cycle is repeated until the judgment requirement of "Is the temperature rise of the resonant inductor lower than 70°C?" is met;

[0029] S6. If there is no solution after iteration, exit the loop and start a new loop: reduce the proposed frequency by 500 Hz and repeat steps 3, 4, and 5.

[0030] In the present invention, in S1, wherein f r is the resonant frequency, L r is the resonant inductor, C r is the resonant capacitor.

[0031] In the present invention, in S1, through a large number of experiments and simulations, a larger resonant capacitance value C that is suitable for the power level and design frequency is selected. r , substitute into the resonant frequency calculation formula Corresponding to the frequency design requirements, the resonant inductance L is obtained by reverse calculation r , the resonant inductance L r The corresponding power level is used to calculate the temperature rise and determine whether it meets the design requirements.

[0032] In the present invention, in S2, when starting the calculation, it is necessary to select a larger resonant capacitor C r The value is multiplied by two times aF, and the resonant inductance value L is obtained by the resonant frequency calculation formula r .

[0033] In the present invention, in S4, the temperature rise calculation is performed by using the resonant inductor L under the specific design power level. r Calculate the temperature rise of the current.

[0034] Specifically, based on the fixed resonant frequency, through the resonant inductor L r The temperature rise is the judgment condition. By reducing the resonant capacitance C r It is worthwhile to derive a new resonant inductor L r The optimal resonant parameter combination is approached by the proposed frequency reduction method. If there is no solution, the resonant inductor L that can continue to operate reliably for a long time is obtained by reducing the proposed frequency. r Value calculation.

[0035] In the present invention, in S4, when the design requirements are not met, the resonant capacitance is reduced and the resonant inductance is increased to keep the resonant frequency unchanged, and then the temperature rise calculation is performed until the design requirements are met, and the output resonant inductance L is r , Capacitance C r value.

[0036] In the present invention, in S5, the C after outputting the result r It must not be less than aF. If the temperature rise requirement is still not met after iteration to aF, the overall DC converter design frequency should be reduced, and the resonant capacitor C should be reduced each time. r The value is reduced by 0.1aF each time during the iteration process. The frequency reduction step after the temperature rise requirement is not met is 500Hz for each iteration.

[0037] Specifically, when the cycle has no solution, the proposed frequency value is reduced and the cycle is restarted, and the frequency is reduced by 500Hz until the resonant inductance L r The value meets the temperature rise limit condition under the high power condition. Under the high power condition, the parameter distribution designed by the parameter design method can operate effectively.

[0038] Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0039] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0040] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for optimizing the design of key parameters of a series resonant DC converter, characterized in that: The specific steps include: S1. Select the design resonant frequency point according to the power level. The relationship between the resonant frequency point and the resonant capacitance and inductance is: S2. Determine the resonant capacitance C by setting the frequency r After reaching the lower limit of the value, multiply the value by Y times; S3. Substitute twice the lower limit of the resonant capacitance into the relationship between the resonant frequency, resonant capacitance and inductance to obtain the resonant inductance L. r value; S4, the resonant inductor L r The temperature rise is calculated based on the value, and the output is determined based on whether the temperature rise of the resonant inductor is lower than 70°C. S5, if in the resonant inductor L r If the judgment condition is not met under the value, the resonant capacitance value is reduced by 0.1aF, and step 3 is repeated, and the cycle is repeated until the judgment requirement of "Is the temperature rise of the resonant inductor lower than 70°C?" is met; S6. If there is no solution after iteration, exit the loop and start a new loop: reduce the proposed frequency by 500 Hz and repeat steps 3, 4, and 5.

2. The method for optimizing the key parameters of a series resonant DC converter according to claim 1, characterized in that: In S1, f r is the resonant frequency, L r is the resonant inductor, C r is the resonant capacitor.

3. The method for designing and optimizing key parameters of a series resonant DC converter according to claim 1, characterized in that: In S1, a large resonant capacitance value C is selected to adapt to the power level and design frequency through a large number of experiments and simulations. r , substitute into the resonant frequency calculation formula Corresponding to the frequency design requirements, the resonant inductance L is obtained by reverse calculation r , the resonant inductance L r The corresponding power level is used to calculate the temperature rise and determine whether it meets the design requirements.

4. The method for designing and optimizing key parameters of a series resonant DC converter according to claim 1, characterized in that: In S2, when starting the calculation, it is necessary to select a larger resonant capacitor C r The value is multiplied by two times aF, and the resonant inductance value L is obtained by the resonant frequency calculation formula r .

5. The method for designing and optimizing key parameters of a series resonant DC converter according to claim 1, characterized in that: In S4, the temperature rise calculation is based on the specific design power level, through the resonant inductor L r Calculate the temperature rise of the current.

6. The method for designing and optimizing key parameters of a series resonant DC converter according to claim 1, characterized in that: In S4, if the design requirements are not met, the resonant capacitance is reduced and the resonant inductance is increased to keep the resonant frequency unchanged, and the temperature rise calculation is performed again until the design requirements are met, and the resonant inductance L is output. r , Capacitance C r value.

7. The method for optimizing the key parameters of a series resonant DC converter according to claim 1, characterized in that: In S5, the output result is C r It must not be less than aF. If the temperature rise requirement is still not met after iteration to aF, the overall DC converter design frequency should be reduced, and the resonant capacitor C should be reduced each time. r The value is reduced by 0.1aF each time during the iteration process. The frequency reduction step after the temperature rise requirement is not met is 500Hz for each iteration.

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