Method, device, medium and equipment for parameter optimization of bidirectional converter

Abstract

The present invention discloses a parameter optimization method, device, medium, and equipment for a bidirectional converter, and relates to the field of direct current power conversion technology. The present invention first determines an initial transformer ratio and initial inductance based on rated operating conditions, then generates a neighborhood based on the initial transformer ratio and initial inductance, and subsequently determines a transformer ratio and inductance combination set that meets the upper limit constraint of switching device losses from the neighborhood. The optimization is performed based on the transformer ratio and inductance combination set to obtain a parameter optimization result, thereby ensuring the operating efficiency of the parameter optimization result under rated operating conditions. Specifically, when optimizing parameters from the transformer ratio and inductance combination set, the present invention fully considers extreme operating conditions, uses the effective value of the inductor current as an optimization indicator, and optimizes each transformer ratio and inductance combination in the transformer ratio and inductance combination set based on the full voltage range of the input voltage and output voltage, thereby quickly obtaining an optimal solution that simultaneously meets the rated operating efficiency and safe operation under extreme operating conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of direct current power conversion, and in particular to a parameter optimization method, device, medium and equipment for a bidirectional converter. Background Art

[0002] Currently, bidirectional converters (Dual Active Bridge, DAB) have the advantages of wide voltage range regulation capability, easy soft switching, multi-port source and storage access, and bidirectional power transmission. In the fields of DC grids, solid-state transformers, electric vehicles, energy storage systems, etc., medium and high frequency isolated DC-DC (DC-DC) topologies represented by bidirectional converters have broad application prospects. They can replace traditional industrial frequency transformers and significantly improve power density, operating efficiency, and fault tolerance and redundancy.

[0003] Efficiency is one of the most core performance indicators of bidirectional converters. Its efficiency optimization is closely related to the modulation strategy. Common modulation strategies for bidirectional converters are categorized based on the combination of modulation degrees of freedom, including single phase shift (SPS), extended phase shift (EPS), double phase shift (DPS), and triple phase shift (TPS). Single phase shift, the most widely used modulation method, suffers from high current stress and loss of soft switching (Zero Voltage Switching, ZVS) characteristics under light load or input-output voltage mismatch conditions, resulting in low efficiency. EPS and DPS control methods reduce backflow power and expand the soft switching range by introducing an internal phase shift angle between the primary and secondary sides, but these solutions are still only local optimal solutions. Based on three-phase-shift modulation, some researchers have proposed strategies for optimizing inductor peak current and inductor RMS current. These strategies, respectively, can achieve optimal peak current and RMS current under ideal conditions across the full voltage and power range. However, these two strategies can cause some switching devices to experience zero current switching (ZCS) under light load conditions, making them less optimal than ZVS. To address the soft switching issue under light load conditions, some researchers have proposed a seamless switching modulation method that balances soft switching of switching devices under light load conditions with optimal RMS inductor current under heavy load conditions, while also providing simple modulation parameter expressions.

[0004] Optimizing the efficiency of bidirectional converters also depends on optimizing magnetic component parameters, primarily the energy storage inductor L and the transformer ratio N. Existing magnetic component optimization strategies primarily prioritize loss and current stress optimization. Loss minimization strategies accurately reflect loss characteristics through iterative numerical optimization, but the loss model is complex and results in lengthy calculation times. Current stress optimization strategies are computationally simpler but do not directly reflect efficiency requirements.

[0005] In summary, the optimization of bidirectional converter efficiency from the perspective of modulation algorithm is relatively mature at present, but the optimization design method of magnetic component parameters has the problem of difficulty in balancing the optimization effect and complexity. Summary of the Invention

[0006] Based on this, it is necessary to provide a parameter optimization method, device, medium and equipment for a bidirectional converter to address the above technical problems.

[0007] The present invention adopts the following technical solutions:

[0008] The present invention provides a parameter optimization method for a bidirectional converter. First, based on a single-phase shift modulation method, the effective value of the inductor current of the bidirectional converter and the switch stress expression of the primary / secondary power device are determined to determine the selected switch device and its loss expression; then, based on the power conversion efficiency of the bidirectional converter and the heat dissipation performance of the switch device, the upper limit of the switch device loss is determined; based on the operating frequency, rated input voltage, rated output voltage, rated power and the upper limit of the switch device loss under rated working conditions, the initial transformer ratio and initial inductance of the bidirectional converter are determined; and then, based on the neighborhood factor, the initial transformer ratio and initial inductance are obtained. Based on the loss expression of the switching device, the neighborhood of the initial transformer ratio and the initial inductance is used to determine the transformer ratio and inductance combination set that meets the upper limit constraint of the switching device loss. Then, for each combination in the transformer ratio and inductance combination set, the maximum effective value of the inductor current of the bidirectional converter corresponding to the combination is determined based on the three-phase shift modulation method within the full voltage range of the input voltage and output voltage. Finally, the transformer ratio and inductance combination corresponding to the minimum value among the maximum effective values ​​of the inductor current in the transformer ratio and inductance combination set is used as the parameter optimization result of the bidirectional converter.

[0009] The present invention provides a parameter optimization device for a bidirectional converter, comprising:

[0010] A selection module is used to determine the effective value of the inductor current of the bidirectional converter and the switch stress expression of the primary / secondary power devices based on the single-phase shift modulation method, so as to determine the selected switching devices and their loss expressions;

[0011] An initial value assignment module is used to determine the upper limit of the switching device loss based on the power conversion efficiency and heat dissipation performance of the bidirectional converter; and to determine the initial transformer ratio and initial inductance of the bidirectional converter based on the operating frequency, rated input voltage, rated output voltage, rated power and upper limit of the switching device loss under rated operating conditions;

[0012] A loss constraint module is used to obtain the neighborhood of the initial transformer ratio and initial inductance based on the neighborhood factor, and determine a set of transformer ratio and inductance combinations that meet the upper limit constraint of the switching device loss from the neighborhood of the initial transformer ratio and initial inductance based on the loss expression of the switching device;

[0013] an inductor current determination module for determining, for each combination of transformer ratio and inductance combination set, the maximum effective value of the inductor current of the bidirectional converter corresponding to the combination within the full voltage range of input voltage and output voltage based on the three-phase shift modulation method;

[0014] The result determination module is used to set the transformer ratio and inductance combination corresponding to the minimum value among the maximum values ​​of the effective value of the inductor current as the parameter optimization result of the bidirectional converter.

[0015] The present invention provides a computer-readable storage medium, wherein the storage medium stores a computer program, and when the computer program is executed by a processor, the parameter optimization method of the bidirectional converter is implemented.

[0016] The present invention provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the parameter optimization method of the bidirectional converter when executing the program.

[0017] At least one of the above technical solutions adopted by the present invention can achieve the following beneficial effects:

[0018] The present invention first determines the initial transformer ratio and initial inductance based on the rated operating conditions, then generates a neighborhood based on the initial transformer ratio and initial inductance, and subsequently determines a transformer ratio and inductance combination set that meets the upper limit constraint of the switching device loss from the neighborhood, and optimizes the transformer ratio and inductance combination set to obtain a parameter optimization result, firstly ensuring the working efficiency of the parameter optimization result under the rated operating conditions; when specifically optimizing the parameters from the transformer ratio and inductance combination set, due to the extreme operating conditions where the primary and secondary voltage ratios of the dual active bridge are highly mismatched, the effective value of the inductor current and the circuit loss will be greatly increased, so the present invention fully considers the extreme operating conditions, takes the effective value of the inductor current as the optimization indicator, and optimizes each transformer ratio and inductance combination in the transformer ratio and inductance combination set based on the full voltage range of the input voltage and output voltage. Compared with complex loss models, it is simpler and accelerates the traversal speed, and can quickly obtain the optimal solution that simultaneously meets the rated working efficiency and operation safety under extreme operating conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0020] Figure 1 A schematic flow chart of a parameter optimization method for a bidirectional converter provided by the present invention;

[0021] Figure 2 A schematic diagram of the main circuit topology of a bidirectional converter provided by the present invention;

[0022] Figure 3 A schematic diagram of a specific process flow for parameter optimization of a bidirectional converter provided by the present invention;

[0023] Figure 4 A schematic diagram of the relationship between switching device loss and inductance value under rated operating conditions provided by the present invention;

[0024] Figure 5 A schematic diagram of the combination range of inductance values ​​and transformer ratios that meets the switching loss requirements under rated operating conditions provided by the present invention;

[0025] Figure 6 A schematic diagram of the relationship between the effective value of the inductor current and the full voltage range when the inductor and transformer ratio are initially selected and meet the rated working conditions provided by the present invention;

[0026] Figure 7 A relationship diagram of the maximum effective value of the inductor current over the entire voltage range as a function of the inductance and the transformer ratio provided by the present invention;

[0027] Figure 8A simulation waveform diagram of the maximum inductor current effective value working condition corresponding to the inductor and transformer ratio optimization result provided by the present invention;

[0028] Figure 9 A schematic diagram of a parameter optimization device for a bidirectional converter provided by the present invention. DETAILED DESCRIPTION

[0029] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and corresponding drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] The technical solutions provided by various embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0031] Figure 1 The following is a flow chart of a parameter optimization method for a bidirectional converter according to the present invention, which specifically includes the following steps:

[0032] S101: Based on the single-phase shift modulation method, determine the effective value of the inductor current of the bidirectional converter and the switch stress expression of the primary / secondary power device to determine the selected switching device and its loss expression.

[0033] S102: Determine the upper limit of the switching device loss based on the power conversion efficiency and heat dissipation performance of the bidirectional converter; determine the initial transformer ratio and initial inductance of the bidirectional converter based on the operating frequency, rated input voltage, rated output voltage, rated power and the upper limit of the switching device loss under rated operating conditions.

[0034] S103: Obtaining the neighborhood of the initial transformer ratio and the initial inductance according to the neighborhood factor, and determining a set of transformer ratio and inductance combinations that meet the upper limit constraint of the switching device loss from the neighborhood of the initial transformer ratio and the initial inductance according to the loss expression of the switching device.

[0035] S104: For each combination in the transformer ratio and inductance combination set, determine the maximum effective value of the inductor current of the bidirectional converter corresponding to the combination within the full voltage range of the input voltage and the output voltage based on the three-phase shift modulation method.

[0036] S105: The transformer ratio and inductance combination corresponding to the minimum value among the maximum values ​​of the effective values ​​of the inductor current is selected as a parameter optimization result of the bidirectional converter.

[0037] For the sake of convenience, the following description will only be based on the server as the execution subject. The server mentioned in the present invention can be a server set up on a business platform, or a device such as a desktop computer or a laptop computer that can execute the solution of the present invention.

[0038] Generally, when designing a bidirectional converter, the designer may first determine the selection of the main circuit switching device based on the index parameters of the bidirectional converter and the contactable suppliers, and determine the approximate expression of the switching device loss based on the data sheet of the switching device.

[0039] In one or more embodiments of the present invention, the selected switching device and its loss expression may be determined based on a single phase-shift modulation method.

[0040] Specifically, the effective value of the inductor current can be determined by the following formula: I rms :

[0041] .

[0042] Primary (secondary) side switch stress expression P sum_p ( P sum_s ) and the loss expression of the switching device P loss As shown in the following formula:

[0043] , ,

[0044] .

[0045] in, is the loss expression of the switching device, is the on-state resistance of the primary switch tube, is the on-state resistance of the secondary switch tube, is the transformer ratio of the bidirectional converter, is the operating frequency of the bidirectional converter, is the single switching loss of the primary switching device, is the single switching loss of the secondary side switching device, is the primary switch stress expression, is the secondary side switch stress expression, The voltage is measured for the loss of the primary switching device. The voltage is measured for the loss of the secondary switching device. The current is measured for the loss of the primary switching device. The current is measured for the loss of the secondary side switching devices, is the effective value of the inductor current, is the inductance of the bidirectional converter, is the input voltage of the bidirectional converter, is the output voltage of the bidirectional converter, is the power of the bidirectional converter. R on_p 、 R on_s 、 E loss_p 、 V ds_p 、 I ds_p 、 E loss_s 、 V ds_s and I ds_s It can be determined from the data sheet of the primary and secondary side switching devices of the main circuit of the bidirectional converter.

[0046] Figure 2 This is a schematic diagram of the main circuit topology of a bidirectional converter in the present invention. Figure 3 This is a schematic diagram of a specific process flow for parameter optimization of a bidirectional converter in the present invention. For subsequent descriptions, please refer to Figure 3 .

[0047] Then, in one or more embodiments of the present invention, the server may determine the initial transformer ratio of the bidirectional converter according to the rated input voltage and the rated output voltage under rated operating conditions using the following formula: .

[0048] Where, is the initial transformer ratio, is the rated input voltage, is the rated output voltage. Engineering applications typically require efficiency at the rated operating point. Because matching the primary and secondary voltages minimizes inductor current stress while ensuring the soft switching (ZVS) capability of the primary and secondary switching devices, thereby reducing device losses, the present invention determines the initial value of the transformer ratio according to the above formula.

[0049] Then, the initial inductance can be determined by the following formula based on the relationship between the operating frequency, rated input voltage, rated output voltage, rated power, initial transformer ratio, and the loss of the switching device and the inductance under rated working conditions: L 0 :

[0050] .

[0051] It can be proved mathematically that P loss It's about L A monotonically decreasing function is obtained by makingP loss - L The numerical solution of the above formula can be quickly obtained by using the image L 0 .

[0052] The server can then form a neighborhood based on the initial transformer ratio and initial inductance of the bidirectional converter, and perform subsequent parameter optimization based on the neighborhood. This ensures that the parameter optimization results work efficiently under rated operating conditions.

[0053] Specifically, the server can obtain the neighborhood of the initial transformer ratio and the initial inductance according to the neighborhood factor through the following formula: [(1-δ) N 0 ~(1+δ) N 0 , (1-δ) L 0 ~(1+δ) L 0 ].

[0054] Where δ is the neighborhood factor.

[0055] Furthermore, since the upper limit of the dual active bridge transmission power is determined by the transformer ratio N and inductance L, and power limits typically exist in certain intervals across the full voltage range, additional boundary conditions determined by the transmission power requirements must be added to the aforementioned boundary conditions.

[0056] Specifically, in one or more embodiments of the present invention, the server may first traverse the neighborhood of the initial transformer ratio and initial inductance according to a preset step size, and determine the switching device loss corresponding to each traversed transformer ratio and inductance value combination based on the switching device loss expression. Then, based on the switching device loss corresponding to each transformer ratio and inductance value combination and the switching device loss upper limit constraint, a set of transformer ratio and inductance combinations that satisfies the switching device loss upper limit constraint is determined.

[0057] For example, in the area determined by the neighborhood and boundary conditions, according to a certain step size [ ΔN , ΔL ]=[ εN 0 , εL 0 ] to search for the best value. For each point ( N 1 , L 1 )∈[(1-δ) N 0 ~(1+δ) N 0 , (1-δ) L0 ~(1+δ) L 0 ] to solve its P loss ( N 1 , L 1 ), all satisfied P loss < P loss_rate of( N 1 , L 1 ) set is {( N 1 , L 1 )| P loss ( N 1 , L 1 )| fs，Vin_rate，Vo_rate，Pfull < P loss_rate}, which is the set of transformer ratio and inductance combinations that meets the upper limit constraint of switching device losses.

[0058] Afterwards, the server can determine, for each combination in the transformer ratio and inductance combination set, the maximum effective value of the inductor current of the bidirectional converter corresponding to the combination within the full voltage range of the input voltage and output voltage based on the three-phase shift modulation method. Specifically, the server can first, for each combination in the transformer ratio and inductance combination set, employ an optimal strategy for the effective value of the inductor current of the bidirectional converter based on the three-phase shift modulation method to determine the effective value of the inductor current of the bidirectional converter corresponding to the combination at the maximum transmission power at each operating point within the full voltage range of the input voltage and output voltage. The server then determines the maximum value of the effective value of the inductor current corresponding to the maximum transmission power at each operating point as the maximum effective value of the inductor current of the bidirectional converter corresponding to the combination within the full voltage range of the input voltage and output voltage.

[0059] For example, for each of the above ( N 1 , L 1 ), the existing TPS-based bidirectional converter inductor current RMS optimal strategy is adopted in the full voltage range, at different operating points ( V in , V o )'s maximum transmission power P max ( V in ,V o ), determine the effective value of the inductor current at each operating point I rms2 ( N 1 , L 1 , P max ( V in , V o ))| fs,Vin,Vo , where the full voltage range I rms2 The maximum point recorded is I rms2_max ( N 1 , L 1 ).

[0060] Finally, the server may use the transformer ratio and inductance combination corresponding to the minimum value among the maximum values ​​of the effective values ​​of the inductor current in the transformer ratio and inductance combination set as the parameter optimization result of the bidirectional converter.

[0061] Continuing with the above example, you can select the above I rms2_max The smallest ( N 1 , L 1 ) combination as the solution of the optimal design, recorded as ( N opt , L opt The optimization results need to be verified for losses and inductor current stress across the full voltage range. If verification fails, the neighborhood of the initial transformer ratio and initial inductance can be re-derived based on the neighborhood factor and the above parameter optimization can be performed based on the updated neighborhood.

[0062] based on Figure 1The parameter optimization method for a bidirectional converter shown in the figure first determines an initial transformer ratio and initial inductance based on rated operating conditions, then generates a neighborhood based on the initial transformer ratio and initial inductance, and subsequently determines a transformer ratio and inductance combination set that meets the upper limit constraint of switching device loss from the neighborhood. Optimization is performed based on the transformer ratio and inductance combination set to obtain parameter optimization results, thereby ensuring the operating efficiency of the parameter optimization results under rated operating conditions. When optimizing parameters from the transformer ratio and inductance combination set, due to the extreme operating conditions where the primary and secondary voltage ratios of the dual active bridge are highly mismatched, the effective value of the inductor current and the circuit loss will increase significantly. Therefore, the present invention fully considers extreme operating conditions, uses the effective value of the inductor current as an optimization indicator, and optimizes each transformer ratio and inductance combination in the transformer ratio and inductance combination set based on the full voltage range of the input voltage and output voltage. Compared with complex loss models, this is simpler, speeds up the traversal speed, and can quickly obtain the optimal solution that simultaneously meets the rated operating efficiency and operational safety under extreme operating conditions.

[0063] On the one hand, the design needs to ensure the working efficiency under rated working conditions. On the other hand, under the extreme working conditions where the primary and secondary voltage ratios of the dual active bridge are highly mismatched, the effective value of the inductor current and the circuit loss will increase significantly, so extreme operating conditions need to be considered. Steps 4 and 5 use the effective value of the inductor current as the optimization index, and the effective value of the inductor current and the input voltage are obtained. V in , output voltage V o and transfer power P Compared with the complex loss model, it is simpler, speeds up the traversal, and can quickly obtain the optimal solution that meets both the rated working efficiency and the safety of operation under extreme working conditions.

[0064] In addition, the present invention also provides an embodiment of the parameter optimization method for the bidirectional converter of the present invention. The index parameters of the bidirectional converter are shown in Table 1.

[0065] Table 1 Design index parameters

[0066]

[0067] The initial value of the transformation ratio is selected as: .

[0068] According to the efficiency requirements, the maximum loss of the switching device under rated working conditions is determined as: .

[0069] Determine the initial transformer ratio of the bidirectional converter based on the rated input voltage and rated output voltage under rated operating conditions According to the above process, make P loss The relationship image with the change of L is as follows: Figure 4 As shown, Figure 4 Schematic diagram of the relationship between switching device loss and inductance value under rated operating conditions in the present invention.

[0070] The initial value of the inductor is determined as: .

[0071] Set a About [ N 0 , L 0 ] is in the range [0~1.3 N 0 , 0~1.3 L 0 ], set the solution step size to [0.01 N 0 ,0.01 L 0 ], then it is satisfied after traversal P loss < P loss_rate of( N 1 , L 1 ) interval such as Figure 5 As shown, Figure 5 Schematic diagram of the combination range of inductance value and transformer ratio that meets the switching loss requirements under rated working conditions in the present invention.

[0072] For each ( N 1 , L 1 ), under this parameter, the optimal effective value modulation method is used to determine the maximum value of the inductor current stress in the full voltage range.

[0073] Taking the rated working condition as an example, the change of the inductor current stress and the maximum value within the full voltage range are obtained as follows: Figure 6 As shown, Figure 6 The figure is a schematic diagram of the relationship between the effective value of the inductor current and the full voltage range when the inductor and the transformer ratio are initially selected under rated working conditions in the present invention.

[0074] For the solution obtained in step 3 ( N 1 , L 1 ) set, and obtain the change of the maximum value of the inductor current stress in the full voltage range corresponding to each point as follows Figure 7 As shown, Figure 7 This is a graph showing the relationship between the maximum effective value of the inductor current in the full voltage range and the inductance and transformer ratio in the present invention. Figure 7 The optimal result is determined as: .

[0075] For the optimal results of transformer ratio and inductance, the maximum effective value of inductor current appears at V in = 450V, V o = 540V, the simulation of this working condition is as follows Figure 8 As shown, Figure 8 This is a simulation waveform diagram of the maximum inductor current effective value working condition corresponding to an inductor and transformer ratio optimization result in the present invention. The simulation result verifies the correctness of the optimization.

[0076] The above is a parameter optimization method for a bidirectional converter provided by one or more embodiments of the present invention. Based on the same idea, the present invention also provides a corresponding parameter optimization device for a bidirectional converter, such as Figure 9 shown.

[0077] Figure 9 A schematic diagram of a parameter optimization device for a bidirectional converter provided by the present invention, comprising:

[0078] A selection module 201 is configured to determine the effective value of the inductor current of the bidirectional converter and the switch stress expressions of the primary and secondary power devices based on a single phase-shift modulation method, so as to determine the selected switching devices and their loss expressions;

[0079] The initial value assignment module 202 is configured to determine an upper limit of switching device losses based on the power conversion efficiency and heat dissipation performance of the bidirectional converter; and to determine an initial transformer ratio and initial inductance of the bidirectional converter based on the operating frequency, rated input voltage, rated output voltage, rated power, and upper limit of switching device losses under rated operating conditions.

[0080] The loss constraint module 203 is configured to obtain a neighborhood of the initial transformer ratio and initial inductance based on the neighborhood factor, and determine a set of transformer ratio and inductance combinations that meet the upper limit constraint on the switching device loss from the neighborhood of the initial transformer ratio and initial inductance based on the loss expression of the switching device;

[0081] an inductor current determination module 204 for determining, for each combination of transformer ratio and inductance combination set, a maximum effective value of the inductor current of the bidirectional converter corresponding to the combination over the full voltage range of input voltage and output voltage based on the three-phase shift modulation method;

[0082] The result determination module 205 is configured to set the transformer ratio and inductance combination corresponding to the minimum value among the maximum effective values ​​of the inductor current as the parameter optimization result of the bidirectional converter.

[0083] The specific definition of the parameter optimization device for a bidirectional converter can be found in the definition of the parameter optimization method for a bidirectional converter described above and will not be repeated here. The various modules in the parameter optimization device for a bidirectional converter described above can be implemented in whole or in part through software, hardware, or a combination thereof. The aforementioned modules can be embedded in or independent of a processor in a computer device in hardware form, or can be stored in a memory in a computer device in software form, so that the processor can call and execute the corresponding operations of the aforementioned modules.

[0084] The present invention also provides a computer-readable storage medium, which stores a computer program, which can be used to execute the above Figure 1 A parameter optimization method for a bidirectional converter is provided.

[0085] The present invention also provides a computer device. At the hardware level, the computer device includes a processor, an internal bus, a network interface, a memory, and a non-volatile memory. Of course, it may also include hardware required for other services. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it to achieve the above Figure 1 A parameter optimization method for a bidirectional converter is provided.

[0086] Those skilled in the art will appreciate that all or part of the processes in the above-described method embodiments can be implemented by instructing the relevant hardware using a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes in the above-described method embodiments. Any reference to memory, storage, database, or other media used in the various embodiments provided herein may include at least one of non-volatile and volatile memory. Non-volatile memory may include read-only memory (ROM), magnetic tape, floppy disk, flash memory, or optical storage. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can take various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0087] The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of the present invention.

Claims

1. A parameter optimization method for a bidirectional converter, characterized in that: include: Based on the single-phase shift modulation method, the effective value of the inductor current of the bidirectional converter and the switch stress expression of the primary / secondary power devices are determined to determine the selected switching devices and their loss expressions; Determine the upper limit of switching device losses based on the power conversion efficiency of the bidirectional converter and the heat dissipation performance of the switching devices; Determine the initial transformer ratio and initial inductance of the bidirectional converter based on the operating frequency, rated input voltage, rated output voltage, rated power, and upper limit of switching device losses under rated operating conditions; Obtaining the neighborhood of the initial transformer ratio and initial inductance according to the neighborhood factor, and determining a set of transformer ratio and inductance combinations that meet the upper limit constraint of the switching device loss from the neighborhood of the initial transformer ratio and initial inductance according to the loss expression of the switching device; For each combination of transformer ratio and inductance combination, based on the three-phase shift modulation method, determine the maximum effective value of the inductor current of the bidirectional converter corresponding to the combination within the full voltage range of input voltage and output voltage; The transformer ratio and inductance combination corresponding to the minimum value among the maximum values ​​of the effective value of the inductor current is taken as the parameter optimization result of the bidirectional converter.

2. The parameter optimization method for a bidirectional converter according to claim 1, wherein: Determining the initial transformer ratio and initial inductance of the bidirectional converter according to the operating frequency, rated input voltage, rated output voltage, rated power, and upper limit of switching device loss under rated operating conditions specifically includes: According to the rated input voltage and rated output voltage under rated operating conditions, the initial transformer ratio of the bidirectional converter is determined by the following formula: ； The initial inductance is determined by the following formula based on the relationship between the operating frequency, rated input voltage, rated output voltage, rated power, initial transformer ratio, switching device loss and inductance under rated operating conditions: ， ， ， ， ； in, is the initial transformer ratio, is the rated input voltage, is the rated output voltage, For the loss expression of the switching device, take the operating frequency under rated conditions , initial transformer ratio , rated input voltage , rated output voltage and rated power The loss of time, is the rated loss of the switching device, is the loss expression of the switching device, is the on-state resistance of the primary switch tube, is the on-state resistance of the secondary switch tube, is the transformer ratio of the bidirectional converter, is the operating frequency of the bidirectional converter, is the single switching loss of the primary switching device, is the single switching loss of the secondary side switching device, is the primary switch stress expression, is the secondary side switch stress expression, The voltage is measured for the loss of the primary switching device. The voltage is measured for the loss of the secondary switching device. The current is measured for the loss of the primary switching device. The current is measured for the loss of the secondary side switching devices, is the effective value of the inductor current, is the inductance of the bidirectional converter, is the input voltage of the bidirectional converter, is the output voltage of the bidirectional converter, is the power of the bidirectional converter.

3. The parameter optimization method for a bidirectional converter according to claim 1, wherein: The obtaining of the neighborhood of the initial transformer ratio and the initial inductance according to the neighborhood factor specifically includes: The neighborhood of the initial transformer ratio and initial inductance is obtained from the neighborhood factor using the following formula: [(1-d) N 0 ~(1+d) N 0 , (1-d) L 0 ~(1+d) L 0 ]; in, is the initial transformer ratio, is the initial inductance, and δ is the neighborhood factor.

4. The parameter optimization method for a bidirectional converter according to claim 1, wherein: The step of determining, based on the loss expression of the switching device, a transformer ratio and inductance combination set that satisfies the upper limit constraint on the switching device loss from a neighborhood of the initial transformer ratio and the initial inductance, specifically includes: Traversing the neighborhood of the initial transformer ratio and initial inductance according to a preset step size, and determining the switching device loss corresponding to each traversed combination of transformer ratio and inductance values ​​according to a loss expression of the switching device; According to the switching device loss and the upper limit constraint of the switching device loss corresponding to each combination of transformer ratio and inductance value, a transformer ratio and inductance combination set that meets the upper limit constraint of the switching device loss is determined.

5. The parameter optimization method for a bidirectional converter according to claim 1, wherein: The step of determining, for each combination of the transformer ratio and inductance combination set, the maximum effective value of the inductor current of the bidirectional converter corresponding to the combination within the full voltage range of the input voltage and the output voltage based on the three-phase shift modulation method specifically includes: For each combination of transformer ratio and inductance, an optimal strategy for the effective value of the inductor current of the bidirectional converter based on three-phase shift modulation is used to determine the effective value of the inductor current corresponding to the bidirectional converter at the maximum transmission power at each operating point within the full voltage range of the input and output voltages. The maximum value among the effective values ​​of the inductor current corresponding to the maximum transmission power at each operating point is determined as the maximum value of the effective value of the inductor current of the bidirectional converter corresponding to the combination within the full voltage range of the input voltage and the output voltage.

6. A parameter optimization device for a bidirectional converter, characterized in that: include: A selection module is used to determine the effective value of the inductor current of the bidirectional converter and the switch stress expression of the primary / secondary power devices based on the single-phase shift modulation method, so as to determine the selected switching devices and their loss expressions; An initial assignment module is used to determine the upper limit of the loss of the switching device according to the power conversion efficiency of the bidirectional converter and the heat dissipation performance of the switching device; Determine the initial transformer ratio and initial inductance of the bidirectional converter based on the operating frequency, rated input voltage, rated output voltage, rated power, and upper limit of switching device losses under rated operating conditions; A loss constraint module is used to obtain the neighborhood of the initial transformer ratio and initial inductance based on the neighborhood factor, and determine a set of transformer ratio and inductance combinations that meet the upper limit constraint of the switching device loss from the neighborhood of the initial transformer ratio and initial inductance based on the loss expression of the switching device; an inductor current determination module for determining, for each combination of transformer ratio and inductance combination set, the maximum effective value of the inductor current of the bidirectional converter corresponding to the combination within the full voltage range of input voltage and output voltage based on the three-phase shift modulation method; The result determination module is used to set the transformer ratio and inductance combination corresponding to the minimum value among the maximum values ​​of the effective value of the inductor current as the parameter optimization result of the bidirectional converter.

7. A computer-readable storage medium, characterized in that The storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 5 is implemented.

8. A computer device, characterized in that: The method comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method according to any one of claims 1 to 5 when executing the program.

Images