DAB converter control method and device based on global minimum return power

Abstract

The present invention discloses a DAB converter control method, device, and storage medium based on global minimum return power. The method includes: obtaining the current power consumption within the DAB converter and determining whether it is equal to a preset power threshold; if not, obtaining the current input voltage and current output voltage of the DAB converter, and then using a particle swarm algorithm to optimize the current phase shift ratio combination used in triple phase shift control of the DAB converter with the goal of minimizing the deviation of the DAB converter's average transmission power and output return power to obtain an optimal phase shift ratio combination; determining an external phase shift angle correction value based on a preset voltage reference value and the current output voltage of the DAB converter, and then controlling the DAB converter in combination with the optimal phase shift ratio combination. By introducing a particle swarm algorithm to solve multi-objective optimization problems, the present invention enables the DAB converter to maintain high energy transmission efficiency after adjustment and reduce the impact of output return power.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and in particular to a DAB converter control method, device and storage medium based on global minimum reflux power. Background Art

[0002] The DAB (Dual Active Bridge) converter is an isolated, bidirectional DC-DC converter. Due to its high efficiency and good power density, it is widely used in electrochemical energy storage systems to achieve power conversion. Electrochemical energy storage systems are typically used in DC microgrids, distributed power generation, and electric vehicles. The DAB converter can improve the power quality of electrochemical energy storage systems during charging or discharging. However, during operation, the DAB converter generates backflow power, which not only reduces the efficiency of the electrochemical energy storage system but may also have an adverse effect on the stability and lifespan of the DAB converter. How to effectively reduce the backflow power of the DAB converter is an urgent problem to be solved. Summary of the Invention

[0003] The present invention provides a DAB converter control method, device and storage medium based on global minimum reflux power to solve one or more technical problems existing in the prior art and at least provide a beneficial option or create conditions.

[0004] In a first aspect, a DAB converter control method based on global minimum reflux power is provided, wherein the DAB converter is applied to a phase shift combination when performing triple phase shift control, the method comprising:

[0005] Obtaining the current power consumption inside the DAB converter and determining whether it is equal to a preset power threshold;

[0006] If not, obtaining the current input voltage and the current output voltage of the DAB converter, and then optimizing the current shift ratio combination of the DAB converter using a particle swarm algorithm with the goal of minimizing the deviation of the average transmission power and the output return power of the DAB converter to obtain the optimal shift ratio combination;

[0007] Determining an external phase shift angle correction value according to a preset voltage reference value and the current output voltage;

[0008] The DAB converter is controlled according to the optimal phase shift ratio combination and the external phase shift angle correction value.

[0009] Furthermore, the DAB converter includes a transformer, an inductor, and a symmetrical input bridge and output bridge. The phase shift combination includes an inner phase shift d1 of the input bridge, an inner phase shift d2 of the output bridge, and an outer phase shift d between the input bridge and the output bridge.

[0010] Further, when it is determined that the current power consumption is equal to the preset power threshold, the current phase shift ratio combination of the DAB converter is used as the optimal phase shift ratio combination.

[0011] Further, the obtaining of the current power consumption inside the DAB converter includes:

[0012] Obtain the current input power and the current output power of the DAB converter;

[0013] Calculate a first difference between the current input power and the current output power, and use the first difference as the current power consumption.

[0014] Further, the average transmission power of the DAB converter is calculated by the following expression:

[0015] When the DAB converter operates in the d≥d2 mode:

[0016]

[0017] When the DAB converter operates in the d<d2 mode:

[0018]

[0019] Where, P is the average transmission power of the DAB converter, V b ,

[0026] ,

[0025] , is the input voltage of the DAB converter, V <"0000002">is the output voltage of the DAB converter, f <"0000003">is the switching frequency, and L is the inductance value of the inductor.

[0020] Further, the output reflux power of the DAB converter is calculated by the following expression:

[0021] When the DAB converter operates in the d≥d2 mode:

[0022]

[0023] When the DAB converter operates in the d<d2 mode:

[0024] <000009�>

[0025] Where, P b is the output reflux power of the DAB converter, n is the turns ratio of the transformer, and k is the voltage conversion ratio.

[0026] Further, the determining of the external phase shift angle correction value according to the preset voltage reference value and the current output voltage includes:

[0027] A second difference between the preset voltage reference value and the current output voltage is calculated, and the second difference is processed by a PI controller to obtain the external phase angle correction value.

[0028] Furthermore, controlling the DAB converter according to the optimal phase shift ratio combination and the external phase shift angle correction value includes:

[0029] Determining an optimal inner shift phase angle of the input bridge according to the optimal inner shift phase ratio of the input bridge;

[0030] Determining an optimal inner shift phase angle of the output bridge according to the optimal inner shift phase ratio of the output bridge;

[0031] determining an optimal external phase shift angle between the input bridge and the output bridge according to the external phase shift angle correction value and an optimal external phase shift angle between the input bridge and the output bridge;

[0032] According to the optimal inner phase shift angle of the input bridge, the optimal inner phase shift angle of the output bridge and the optimal outer phase shift angle between the input bridge and the output bridge, all gate pulse signals of the DAB converter are generated by using a phase accumulator and a timer to control the DAB converter.

[0033] In a second aspect, a computer device is provided, comprising a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the DAB converter control method based on global minimum backflow power as described in the first aspect.

[0034] In a third aspect, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the DAB converter control method based on global minimum backflow power as described in the first aspect is implemented.

[0035] The present invention has at least the following beneficial effects: when the DAB converter fails to reach the expected power output level, the particle swarm algorithm is used to find the optimal phase shift combination of the DAB converter with the goal of minimizing the deviation of the average transmission power and the output return power of the DAB converter, and it is proposed that the external phase shift angle of the DAB converter needs to be corrected when the optimal phase shift combination is put into use, so that the DAB converter can maintain a high energy transmission efficiency as much as possible after adjustment operation and reduce the influence of the output return power, thereby enhancing the stability of the DAB converter. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the technical solution of the present invention and do not constitute a limitation to the technical solution of the present invention.

[0037] Figure 1 Schematic diagram of the composition of a DAB converter in an embodiment of the present invention;

[0038] Figure 2 1 is a flow chart of a DAB converter control method based on global minimum reflux power in an embodiment of the present invention;

[0039] Figure 3 Schematic diagram of the hardware structure of a computer device in an embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0041] It should be noted that although a logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in an order different from that in the flowchart. The terms "first," "second," and the like in the specification, claims, and drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than that shown or described herein.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein are for the purpose of describing the embodiments of this application only and are not intended to limit this application.

[0043] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner.In the following description, many specific details are provided so as to provide a full understanding of the embodiments of the present application. However, it will be appreciated by those skilled in the art that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps etc. can be adopted. In other cases, known methods, devices, implementations or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0044] The flowcharts shown in the accompanying drawings are for illustrative purposes only and do not necessarily include all contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps may be decomposed, while others may be combined or partially combined. Therefore, the actual execution order may vary depending on the actual situation.

[0045] Please refer to Figure 1 , Figure 1 1 is a schematic diagram of the composition of a DAB converter provided by an embodiment of the present invention. The DAB converter includes an input bridge, an inductor L, a transformer HFT, and an output bridge. The input bridge and the output bridge are symmetrical with each other. The input bridge serves as the power supply side, and the output bridge serves as the load side.

[0046] More specifically, the input bridge includes a first switching tube S1, a second switching tube S2, a third switching tube S3, a fourth switching tube S4, a first diode T1 anti-parallel to the first switching tube S1, a second diode T2 anti-parallel to the second switching tube S2, a third diode T3 anti-parallel to the third switching tube S3, a fourth diode T4 anti-parallel to the fourth switching tube S4, and a first filter capacitor C1. The first switching tube S1 and the second switching tube S2 form a first bridge arm, the third switching tube S3 and the fourth switching tube S4 form a second bridge arm, the first filter capacitor C1 is connected in parallel to the first bridge arm, and the first bridge arm and the second bridge arm are connected in parallel. The middle node of the first bridge arm is connected to the first primary end point of the transformer HFT via the inductor L, and the middle node of the second bridge arm is connected to the second primary end point of the transformer HFT.

[0047] More specifically, the output bridge includes a fifth switching transistor S5, a sixth switching transistor S6, a seventh switching transistor S7, an eighth switching transistor S8, a fifth diode T5 anti-parallel to the fifth switching transistor S5, a sixth diode T6 anti-parallel to the sixth switching transistor S6, a seventh diode T7 anti-parallel to the seventh switching transistor S7, an eighth diode T8 anti-parallel to the eighth switching transistor S8, and a second filter capacitor C2. The fifth switching transistor S5 and the sixth switching transistor S6 form a third bridge arm, and the seventh switching transistor S7 and the eighth switching transistor S8 form a fourth bridge arm. The third bridge arm is connected in parallel with the fourth bridge arm, and the fourth bridge arm is connected in parallel with the second filter capacitor C2. The middle node of the third bridge arm is connected to the first secondary end point of the transformer HFT, and the middle node of the fourth bridge arm is connected to the second secondary end point of the transformer HFT.

[0048] In an embodiment of the present invention, triple phase shift control is performed on the DAB converter. In this case, the phase shift combinations required to be applied to the DAB converter include the following:

[0049] (1) The shift ratio d between the input bridge and the output bridge refers to the shift ratio between the first switch S1 and the fifth switch S5;

[0050] (2) The internal shift ratio d1 of the input bridge refers to the internal shift ratio between the first switch S1 and the fourth switch S4, or the internal shift ratio between the second switch S2 and the third switch S3;

[0051] (3) The inward shift ratio d2 of the output bridge refers to the inward shift ratio between the fifth switch S5 and the eighth switch S8, or the inward shift ratio between the sixth switch S6 and the seventh switch S7.

[0052] On this basis, Figure 2 1 is a flow chart of a DAB converter control method based on global minimum reflux power provided by an embodiment of the present invention, the method comprising the following steps:

[0053] Step S110, obtaining the current power consumption inside the DAB converter and determining whether it is equal to a preset power threshold; if so, executing step S120; if not, executing step S130;

[0054] Step S120: taking the current shift phase combination of the DAB converter as the optimal shift phase combination;

[0055] Step S130: obtaining the current input voltage and the current output voltage of the DAB converter, and then optimizing the current shift ratio combination of the DAB converter using a particle swarm algorithm with the goal of minimizing the deviation of the average transmission power and the output return power of the DAB converter to obtain an optimal shift ratio combination;

[0056] Step S140: determining an external phase shift angle correction value according to a preset voltage reference value and the current output voltage;

[0057] Step S150: Control the DAB converter according to the optimal phase shift ratio combination and the external phase shift angle correction value.

[0058] In some embodiments, the current power consumption inside the DAB converter mentioned in the above step S110 is obtained by: obtaining the current input power of the DAB converter, which can be obtained by placing the detection terminal of the power meter at the input end of the DAB converter (i.e., the power supply side of the DAB converter) for detection; obtaining the current output power of the DAB converter, which can be obtained by placing the detection terminal of the power meter at the output end of the DAB converter (i.e., the load side of the DAB converter) for detection; calculating a first difference between the current input power and the current output power of the DAB converter and defining it as the current power consumption output inside the DAB converter.

[0059] In the above step S110, by comparing the current power consumption inside the DAB converter with a preset power threshold, it can be determined whether the DAB converter currently reaches the expected power output level, so as to judge whether it is necessary to further optimize the current phase-shift ratio combination of the DAB converter and avoid wasting computing resources.

[0060] In some embodiments, the implementation process of the above step S130 includes but is not limited to the following:

[0061] Step S131: Obtain the current input voltage of the DAB converter, which can be detected by placing the detection terminal of the voltmeter at the input end of the DAB converter (i.e., the power supply side of the DAB converter).

[0062] Step S132: Obtain the current output voltage of the DAB converter, which can be detected by placing the detection terminal of the voltmeter at the output end of the DAB converter (i.e., the load side of the DAB converter).

[0063] Step S133: Set the decision variables to be applied in the particle swarm algorithm as X = {d, d1, d2}, and set the constraint conditions of the decision variable X as: 0 < d < 1, 0 < d1 < 1, 0 < d2 < 1, and 0 < d + d1 + d2 < 1. The decision variable X is usually encoded as the position of the particle, and each particle represents a solution in the problem space.

[0064] Step S134: Set two cost functions to be applied in the particle swarm algorithm. The first cost function is used to solve the deviation between the average transmission power of the DAB converter and the preset average transmission power reference value, and the second cost function is used to solve the output return power of the DAB converter. In the particle swarm algorithm, the optimization problem of the decision variable X is achieved with the goal of minimizing the two cost functions;

[0065] Among them, the formula for solving the average transmission power of the DAB converter is: [[ID=二十]]

[0066] [[ID=二十一]] [[ID=二十二]] [[ID=二十三]]

[0067] The formula for solving the output return power of the DAB converter is:

[0068] ​​​​​​​​is the switching frequency, and f is set considering that the average current of the inductor L in one switching period 2π is zero. S =1 / (2π), L is the inductance value of the inductor L, P b is the output return power of the DAB converter, n is the transformation ratio of the transformer HFT, k is the voltage conversion ratio and k = V i / (nV o ).

[0070] Step S135: Set the basic parameters required for the particle swarm algorithm, including the size of the particle swarm (ie, the number of particles participating in the search), the maximum number of iterations T, and the number of iterations. max , inertia weight w, cognitive coefficient c1, social coefficient c2 and an empty repository, which is mainly used to save all non-dominated solutions found by the particle swarm during the iterative search process.

[0071] Step S136: Randomly initialize the particle swarm according to the constraints of the decision variable X.

[0072] Step S137: In the tth iteration, two cost function values ​​corresponding to each particle are calculated based on the current input voltage and the current output voltage of the DAB converter and the two cost functions;

[0073] More specifically, the shift ratio combination indicated by each particle and the current input voltage and the current output voltage of the DAB converter are substituted into the two cost functions for calculation, thereby obtaining the two cost function values ​​corresponding to the particle.

[0074] Step S138: Update the repository using a non-dominant solution according to the two cost function values ​​corresponding to each particle;

[0075] More specifically, for each particle contained in the particle swarm, according to the two cost function values ​​corresponding to the particle, the particle is regarded as a new solution and compared with each non-dominated solution currently stored in the repository, which is divided into the following four cases: (1) When the new solution can dominate one or more non-dominated solutions currently stored in the repository, the dominated non-dominated solutions are removed from the repository and the solution is added to the repository; (2) When there is no domination relationship between the new solution and all non-dominated solutions currently stored in the repository and the capacity of the repository is not full, the solution is directly added to the repository; (3) When there is no domination relationship between the new solution and all non-dominated solutions currently stored in the repository, but the capacity of the repository is full, the non-dominated solution with the smallest crowding distance (or density estimate) is removed from all non-dominated solutions currently stored in the repository and the solution is added to the repository; (4) When the new solution can be dominated by all non-dominated solutions currently stored in the repository, the solution is discarded, that is, the solution will not be added to the repository.

[0076] Step S139: Update the position and velocity of each particle using the following mathematical expression:

[0077]

[0078] Where V i (t) is the updated velocity of the i-th particle, V i (t-1) is the speed of the i-th particle before the update, pbest i (t-1) is the optimal position of the i-th particle before the update, gbest(t-1) is the global optimal position of the particle swarm before the update, X i (t) is the updated position of the i-th particle, X i (t-1) is the position of the i-th particle before updating.

[0079] Step S1310: Determine t <T max Is it true? If so, assign t+1 to t and return to execute the above step S137; if not, select a suitable non-dominated solution from the Pareto optimal solution set currently stored in the storage library and output it. The non-dominated solution is the optimal shift ratio combination;

[0080] Optionally, a non-dominated solution output with the minimum output return power of the corresponding DAB converter is selected from the Pareto optimal solution set. It is also possible to consider selecting a non-dominated solution output with the minimum deviation between the average transmission power of the corresponding DAB converter and a preset average transmission power reference value from the Pareto optimal solution set.

[0081] In the multi-objective particle swarm algorithm, considering that over-reliance on the dominant solution may cause the algorithm to fall into a local optimal solution, the use of non-dominant solutions can incorporate some non-dominant solutions into the repository to increase the diversity of the search and the global exploration capability, so that the final optimal shift ratio combination can meet the requirements of achieving the required power transmission level and reducing the output return power to make it as close to zero as possible.

[0082] In some embodiments, an optional implementation of the above step S140 is: calculating a second difference between the preset voltage reference value and the current output voltage of the DAB converter and processing it through a PI controller, and the PI controller finally achieves a stable output voltage by adjusting the external phase shift angle between the corresponding switching tubes of the two bridges, that is, using the PI controller to adjust the current output voltage of the DAB converter to be equal to the preset voltage reference value to obtain the external phase shift angle correction value D 2T .

[0083] In the DAB converter, the external phase shift angle is one of the key factors affecting the energy transmission efficiency. By dynamically adjusting the size of the external phase shift angle according to the actual operating conditions of the DAB converter and combining it with a PI controller, the DAB converter can achieve efficient and stable energy transmission.

[0084] In some embodiments, the optimal shift phase combination includes an optimal external shift phase d between the input bridge and the output bridge. b , the optimal inward shift of the input bridge compared to d 1b Compared with the optimal inward shift of the output bridge d 2b The implementation process of step S150 includes but is not limited to the following:

[0085] Step S151: Based on the optimal inner shift of the input bridge d 1b , the optimal internal phase shift angle of the input bridge is calculated to be D 1b =d 1b π;

[0086] Step S152: Based on the optimal inner shift of the output bridge d 2b , the optimal internal phase shift angle of the output bridge is calculated to be D 2b =d 2b π;

[0087] Step S153: Based on the optimal outward shift comparison d between the input bridge and the output bridge b And the external phase angle correction value D 2T , calculate the optimal external shift phase angle between the input bridge and the output bridge as D b =d b π+D 2T ;

[0088] Step S154: Based on the optimal internal phase shift angle D of the input bridge 1b , the optimal internal phase shift angle D of the output bridge 2b And the optimal external phase shift angle D between the input bridge and the output bridge b , combined with a timer and a phase accumulator to generate all gate pulse signals of the DAB converter (i.e., the PWM signal of each switch tube) to control the DAB converter, that is, using each gate pulse signal to control the corresponding switch tube contained in the DAB converter.

[0089] More specifically, in the DAB converter, the formation of the PWM (Pulse-Width Modulation) signal actually determines the efficiency of power conversion and the waveform quality of the output voltage. An optional implementation of the above step S154 is: initializing the phase accumulator to make its value zero or a preset starting phase value, and setting the accumulation step of the phase accumulator according to the preset PWM frequency requirement. The accumulation step is proportional to the switching frequency f.S The timer is initialized and the period of the timer is set to match the period of the PWM signal. The timer is controlled to generate an interrupt event at the end of each period, so that the value of the phase accumulator increases according to the accumulation step. When the value of the phase accumulator reaches the optimal internal phase shift angle D of the input bridge, the phase accumulator is automatically reset. 1b When , four PWM signals corresponding to the four switch tubes (S1-S4) included in the input bridge are generated, and when the value of the phase accumulator is added to the optimal external phase shift angle D between the input bridge and the output bridge b Then the optimal internal phase shift angle D of the output bridge is reached 2b When the output bridge is turned on, four PWM signals corresponding to the four switching tubes (S5-S8) included in the output bridge are generated, and a dead time needs to be set between the two PWM signals corresponding to the two switching tubes on the same bridge arm to avoid the two switching tubes being turned on at the same time and causing a short circuit.

[0090] In an embodiment of the present invention, when a DAB converter fails to reach an expected power output level, a particle swarm algorithm is used to find an optimal phase shift combination of the DAB converter with the goal of minimizing the deviation of the average transmission power and the output return power of the DAB converter. It is also proposed that when the optimal phase shift combination is put into use, the external phase shift angle of the DAB converter needs to be corrected, so that the DAB converter can maintain a high energy transmission efficiency as much as possible after adjustment operation and reduce the influence of the output return power, thereby enhancing the stability of the DAB converter.

[0091] In addition, an embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon. When executed by a processor, the computer program implements a DAB converter control method based on global minimum reflux power according to the above embodiment. The computer-readable storage medium includes, but is not limited to, any type of disk (including floppy disks, hard disks, optical disks, CD-ROMs, and magneto-optical disks), ROM (Read-Only Memory), RAM (Random Access Memory), EPROM (Erasable Programmable Read-Only Memory), EEPROM (Electrically Erasable Programmable Read-Only Memory), flash memory, magnetic cards, or optical cards. In other words, a storage device includes any medium that stores or transmits information in a readable form by a device (e.g., a computer, a mobile phone, etc.), and may be a read-only memory, a magnetic disk, or an optical disk.

[0092] also, Figure 3 2 is a schematic diagram of the hardware structure of a computer device provided in an embodiment of the present invention, wherein the computer device includes a processor 220, a memory 230, an input unit 240, a display unit 250 and other components. It can be understood by those skilled in the art that Figure 3 The device structure components shown do not constitute a limitation on all devices, and may include more or fewer components than shown, or combine certain components. The memory 230 can be used to store the computer program 210 and various functional modules, and the processor 220 runs the computer program 210 stored in the memory 230, thereby executing various functional applications and data processing of the device. The memory can be an internal memory or an external memory, or include an internal memory and an external memory. The internal memory may include a read-only memory (ROM), a programmable ROM (PROM), an electrically programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), a flash memory or a random access memory. The external memory may include a hard disk, a floppy disk, a USB flash drive, a magnetic tape, etc. The memory 230 disclosed in the embodiment of the present invention includes but is not limited to the above-mentioned types of memory. The memory 230 disclosed in the embodiment of the present invention is only an example and not a limitation.

[0093] The input unit 240 is used to receive input signals and keywords entered by the user. The input unit 240 may include a touch panel and other input devices. The touch panel can detect user touch operations on or near it (e.g., operations performed by a user using a finger, stylus, or any other suitable object or accessory on or near the touch panel) and drive corresponding connected devices according to pre-set programs. Other input devices may include, but are not limited to, one or more of a physical keyboard, function keys (e.g., playback control keys, on / off keys, etc.), a trackball, a mouse, a joystick, etc. The display unit 250 can be used to display information entered by the user or provided to the user, as well as various menus of the terminal device. The display unit 250 may take the form of a liquid crystal display, an organic light-emitting diode, etc. The processor 220 is the control center of the terminal device, connecting various components of the entire device using various interfaces and circuits. It performs various functions and processes data by running or executing software programs and / or modules stored in the memory 230 and accessing data stored in the memory 230.

[0094] As an embodiment, the computer device includes a processor 220, a memory 230 and a computer program 210, wherein the computer program 210 is stored in the memory 230 and is configured to be executed by the processor 220, and the computer program 210 is configured to execute a DAB converter control method based on global minimum return power in the above embodiment.

[0095] The terms "including" and "having" and any variations thereof in the specification of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or are inherent to these processes, methods, products or apparatuses.

[0096] In the present application, it should be understood that "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0097] Although the description of the present application has been quite detailed and specifically describes several embodiments, it is not intended to be limited to any of these details or embodiments or any particular embodiment, but should be considered to provide a broad possible interpretation of these claims by reference to the appended claims, taking into account the prior art, so as to effectively cover the intended scope of the present application. In addition, the above description of the present application is based on the embodiments foreseen by the inventors, which is intended to provide a useful description, and those non-substantial changes to the present application that have not yet been foreseen may still represent equivalent changes to the present application.

Claims

1. A DAB converter control method based on global minimum reflux power, characterized in that: The DAB converter is applied to the phase shift combination when performing triple phase shift control, and the method includes: Obtaining the current power consumption inside the DAB converter and determining whether it is equal to a preset power threshold; If not, obtaining the current input voltage and the current output voltage of the DAB converter, and then optimizing the current shift ratio combination of the DAB converter using a particle swarm algorithm with the goal of minimizing the deviation of the average transmission power and the output return power of the DAB converter to obtain the optimal shift ratio combination; Determining an external phase shift angle correction value according to a preset voltage reference value and the current output voltage; Controlling the DAB converter according to the optimal phase shift angle combination and the external phase shift angle correction value; The DAB converter includes a transformer, an inductor, and a symmetrical input bridge and output bridge. The phase shift combination includes an internal phase shift of the input bridge. , the output bridge is shifted inward compared to and the outward shift between the input bridge and the output bridge compared ; The average transmission power of the DAB converter is calculated by the following expression: When the DAB converter operates in When in mode: When the DAB converter operates in When in mode: Where, is the average transmission power of the DAB converter, is the input voltage of the DAB converter, is the output voltage of the DAB converter, is the switching frequency, is the inductance value of the inductor.

2. The DAB converter control method based on global minimum reflux power according to claim 1, characterized in that: When it is determined that the current consumed power is equal to the preset power threshold, the current shift phase ratio combination of the DAB converter is used as the optimal shift phase ratio combination.

3. The DAB converter control method based on global minimum reflux power according to claim 1, characterized in that: The obtaining of the current power consumption inside the DAB converter includes: Obtaining the current input power and the current output power of the DAB converter; A first difference between the current input power and the current output power is calculated, and the first difference is used as the current consumed power.

4. The DAB converter control method based on global minimum reflux power according to claim 1, characterized in that: The output return power of the DAB converter is calculated by the following expression: When the DAB converter operates in When in mode: When the DAB converter operates in When in mode: in, is the output return power of the DAB converter, is the transformation ratio of the transformer, is the voltage conversion ratio.

5. The DAB converter control method based on global minimum reflux power according to claim 1, characterized in that: The determining of the external phase shift angle correction value according to the preset voltage reference value and the current output voltage includes: A second difference between the preset voltage reference value and the current output voltage is calculated, and the second difference is processed by a PI controller to obtain the external phase angle correction value.

6. The DAB converter control method based on global minimum reflux power according to claim 1, characterized in that: The controlling the DAB converter according to the optimal phase shift angle combination and the external phase shift angle correction value comprises: Determining an optimal inner shift phase angle of the input bridge according to the optimal inner shift phase ratio of the input bridge; Determining an optimal inner shift phase angle of the output bridge according to the optimal inner shift phase ratio of the output bridge; determining an optimal external phase shift angle between the input bridge and the output bridge according to the external phase shift angle correction value and an optimal external phase shift angle between the input bridge and the output bridge; According to the optimal inner phase shift angle of the input bridge, the optimal inner phase shift angle of the output bridge and the optimal outer phase shift angle between the input bridge and the output bridge, all gate pulse signals of the DAB converter are generated by using a phase accumulator and a timer to control the DAB converter.

7. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: The processor executes the computer program to implement the DAB converter control method based on global minimum backflow power according to any one of claims 1 to 6.

8. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the DAB converter control method based on global minimum backflow power according to any one of claims 1 to 6 is implemented.

Images