Model prediction PI control method and device for improving dynamic performance of converter

Abstract

The invention provides a model prediction PI control method for improving the dynamic performance of a converter. Comprising the following steps: detecting actual voltage V1 of a bus side; battery side actual voltage V2 and current reference instruction value Iref are input into a PI controller of a prediction model to calculate and obtain an initial out-shift phase angle # imgabs0 # in a control beat, the difference between the current instruction Iref and actually detected battery charging and discharging current Ibat is obtained to obtain a current error signal ei, and the current error signal ei is input into a PI controller Gic to obtain an out-shift phase angle increment # imgabs1 # initial out-shift phase angle in the control beat. Summing the # imgabs2 # and the external phase shift angle increment # imgabs3 # to obtain an actually output external phase shift angle # imgabs4 #; judging the working mode of the dual phase shift DAB converter at the moment according to the external phase shift angle # imgabs5 #, the actual voltage V1 and the battery side actual voltage V2 value; and an inner phase shift angle # imgabs6 # DPWM pulse generation module in a corresponding working mode is output to generate a driving pulse signal to control the charging and discharging current Ibat of the battery to quickly follow and respond to a current reference instruction value Iref issued.

Description

Technical Field

[0001] The present invention relates to the technical field of power DC converter control, and in particular to a model prediction PI control method and device for improving the dynamic performance of a converter. Background Art

[0002] Renewable energy is characterized by intermittency, volatility and uncertainty. As the proportion of new energy continues to increase, the stable operation of the power grid is challenged.

[0003] Energy storage has the function of shaving peak loads and filling valley loads, which is beneficial to improving the power supply reliability and operation stability of the power grid system. It has developed rapidly in recent years. The energy storage power station with batteries as the core absorbs excess electric energy for storage when the load is low, and releases the stored energy to the system load during peak load, participating in the peak load and frequency regulation of the power grid.

[0004] The dual active bridge converter has fewer power components than the resonant converter due to its isolation function, and can achieve smooth switching of the charge and discharge modes, which is particularly suitable for battery charging and discharging applications. The single phase-shifted DAB converter has large circulating power, high turn-off current stress of the switching device, and difficulty in achieving soft switching under light load, which limits the further improvement of the system power. To solve such problems, the dual phase-shifted DAB converter introduces an additional internal phase shift angle as an adjustment degree of freedom, which can significantly broaden the light load soft switching range and suppress the circulating power, and is widely used in high-voltage and high-power applications.

[0005] As the core component of the battery energy storage system and the battery charging and discharging test system, improving the dynamic performance of the dual-phase-shifted DAB converter is an effective means to improve the operating performance of the energy storage system. However, the dual-phase-shifted DAB converter has multiple working modes due to the introduction of additional phase-shifting degrees of freedom, making the control more complex. Multiple working modes and multiple phase-shifting adjustments make it difficult to adjust the controller parameters. In addition, as the voltage of the connected battery fluctuates over a wide range and the current command changes drastically, its dynamic characteristics are difficult to maintain optimal.

[0006] At present, the control part of the dual-phase DAB converter is still mainly based on PI control. The PI parameters adjusted under specific working conditions have the characteristics of high adjustment accuracy, fast dynamic response, and small overshoot. However, as the voltage of the connected battery changes in a wide range, the working characteristics of the dual-phase DAB converter change accordingly. At this time, traditional PI control is difficult to maintain its dynamic performance and cannot achieve optimal dynamic regulation within a wide voltage range. In response to this, some scholars introduced model predictive control into the dual-phase DAB converter because its prediction model contains information related to battery voltage and current, which can adapt to various complex working conditions and maintain optimal dynamic performance. However, model predictive control relies on the measurement of circuit parameters, and cannot accurately follow the current reference instruction during actual operation. In addition, the modeling process is complex and the workload is huge.

[0007] Therefore, it is necessary to improve and enhance the existing technology, and propose a model predictive PI control method to improve the dynamic performance of the dual-phase-shifted DAB converter, which combines the advantages of PI control and model predictive control so that it not only has high-precision current control capability, but also achieves excellent dynamic performance under various working conditions.

[0008] In view of this, it is necessary to provide a new model predictive PI control method and device for improving the dynamic performance of the converter to overcome the above-mentioned defects. Summary of the invention

[0009] The purpose of the present invention is to provide a model predictive PI control method and device for improving the dynamic performance of the converter, so as to solve the problem of slow dynamic response or excessive overshoot in the field of battery charging and discharging in a wide voltage range of the double phase shift DAB converter under the existing PI control mode.

[0010] In order to achieve the above object, the technical solution provided by the present invention is implemented as follows: a model prediction PI control method for improving the dynamic performance of a converter comprises the following steps:

[0011] S1: Detect the actual voltage V1 on the input bus side, the actual voltage V2 on the battery side, and the battery charge and discharge current I bat ;

[0012] S2: The actual voltage V1 on the bus side, the actual voltage V2 on the battery side and the current reference command value I ref The initial outward phase angle within the control beat is calculated in the PI controller of the input prediction model

[0013] S3: Set the current command I ref and the actual detected battery charge and discharge current I bat The current error signal e is obtained by subtracting i And input to the PI controller G ic The external phase angle increment within this control beat is obtained

[0014] S4: Initial external phase angle and the external phase angle increment The summation gives the actual output external phase angle within this control beat. According to the actual output external phase shift angle The actual voltage V1 and the actual voltage V2 on the battery side are detected to determine the working mode of the dual phase-shift DAB converter at this time, and output the internal phase shift angle under the corresponding working mode.

[0015] S5: The calculated external phase angle and internal phase angle Input to the DPWM pulse generation module to generate a drive pulse signal to control the battery charge and discharge current I bat The current reference command value I issued by the fast follow-up response ref .

[0016] Preferably, the calculation process of the PI controller of the prediction model described in step S2 is:

[0017]

[0018] In the above formula (1), L is the power inductance value, f s is the switching frequency and N is the transformer ratio.

[0019] Preferably, the dual phase-shift DAB converter in step S4 is configured according to the external phase-shift angle The working mode is specifically divided into working mode A and working mode B according to the relationship between the actual voltage V1 and the actual voltage V2 on the battery side. The determination basis of the working mode A and the working mode B is:

[0020]

[0021] In the above formula (2), the voltage ratio m=NV2 / V1.

[0022] Preferably, the internal phase shift angle in the corresponding working mode described in step S4 is The calculation process is:

[0023]

[0024] A model prediction PI control circuit for improving the dynamic performance of a converter comprises: a DC power supply, a dual phase-shift DAB converter, a battery and a digital control system; the DC power supply is electrically connected to the dual phase-shift DAB converter, the dual phase-shift DAB converter is electrically connected to the battery, and the digital control system is electrically connected to the dual phase-shift DAB converter and the battery.

[0025] Preferably, the dual phase shift converter includes a capacitor C1, a MOS transistor Q1, a MOS transistor Q2, a MOS transistor Q3, a MOS transistor Q4, a MOS transistor Q5, a MOS transistor Q6, a MOS transistor Q7, a MOS transistor Q8, and a high frequency transformer T r , Excitation inductance L m , output filter capacitor C f And the output filter inductor L f ;

[0026] One end of the capacitor C1 is electrically connected to the positive electrode of the DC power supply, the drain of the MOS transistor Q1 and the drain of the MOS transistor Q3, and the other end of the capacitor C1 is electrically connected to the negative electrode of the DC power supply, the source of the MOS transistor Q2 and the source of the MOS transistor Q4. The source of the MOS transistor Q1 is electrically connected to the drain of the MOS transistor Q2, and the source of the MOS transistor Q3 is electrically connected to the drain of the MOS transistor Q4.

[0027] The excitation inductance L m One end of the excitation inductor L is electrically connected to the source of the MOS tube Q1. m The other end is connected to the high frequency transformer T r One end of the primary winding is electrically connected to the high frequency transformer T r The other end of the primary winding is electrically connected to the drain of the MOS tube Q4.

[0028] The source of the MOS transistor Q5 is electrically connected to the drain of the MOS transistor Q6, and the drain of the MOS transistor Q5 is electrically connected to the drain of the MOS transistor Q7 and the output filter capacitor C f One end of the output filter inductor L f The source of the MOS tube Q6 is electrically connected to the source of the MOS tube Q8 and the output filter capacitor C f The other end is electrically connected to the negative pole of the battery, and the output filter inductor L f The other end of is electrically connected to the positive electrode of the battery, the source of the MOS tube Q5 is electrically connected to the drain of the MOS tube Q6, the source of the MOS tube Q7 is electrically connected to the drain of the MOS tube Q8,

[0029] The high frequency transformer T r One end of the secondary winding is electrically connected to the source of the MOS tube Q5, and the high-frequency transformer T r The other end of the secondary winding is electrically connected to the drain of the MOS tube Q8.

[0030] Preferably, the digital control system comprises a prediction model, a PI controller, a dual phase shift control unit and a DPWM pulse generation module which are electrically connected in sequence, the prediction model is electrically connected to the battery, the output filter inductor Lf The PI controller is electrically connected to form a difference module, and the DPWM pulse generation module is electrically connected to the MOS tubes Q1-Q8.

[0031] A model prediction PI control system for improving the dynamic performance of a converter, comprising: a detection module, a differential module, an input module and a control module, wherein the detection module, the differential module, the input module and the control module are electrically connected to each other;

[0032] The detection module is used to detect the actual voltage V1 on the input bus side, the actual voltage V2 on the battery side, and the battery charge and discharge current I bat The actual voltage V1, the actual voltage V2 on the battery side and the battery charge and discharge current I bat Input to the PI controller of the prediction model, the battery current I bat Input to the difference module;

[0033] As a difference module, it is used to convert the reference output current reference command value I ref and battery charge and discharge current I bat The current error signal e is obtained by subtracting i ;

[0034] The calculation module is used to calculate the initial external phase angle of the PI controller in this control beat. Outward phase angle increment And the actual output external phase shift angle And calculate the internal phase shift angle in the corresponding working mode

[0035]

[0036] A control module is used to utilize the calculated external phase shift angle And the corresponding internal phase angle A driving pulse signal is obtained to quickly follow and respond to the current instruction of the charging and discharging system.

[0037] A non-transitory computer-readable storage medium stores a computer program, which is executed by a processor to implement the steps of a model prediction PI control method for improving the dynamic performance of a converter.

[0038] Compared with the prior art, the beneficial effects are:

[0039] 1. The model prediction PI control method provided by the present invention obtains the initial phase shift value of the PI controller in each calculation cycle by simplifying the working model of the dual phase-shift DAB converter; the incremental part of the phase shift value in each calculation cycle is output by the PI controller; the two are superimposed to obtain the actual output phase shift value in each calculation cycle. Finally, the corresponding driving pulse is generated by the DPWM pulse generation module, thereby controlling the power switch device of the converter to turn on and off according to a certain rule, and realizing high-precision and fast following of the battery charging and discharging current instructions under various working conditions.

[0040] 2. This control method combines the advantages of PI control and model predictive control. On the premise that the control current accuracy is guaranteed by PI control, it simplifies the working model of the dual-phase-shifted DAB converter, reduces the amount of calculation, and can make up for the defects of traditional PI control. It can maintain excellent dynamic performance under various working conditions, with fast response speed and no overshoot.

[0041] Other features and advantages of the present invention will be set forth in the following description, and part will be apparent from the description, or can be understood by implementation of the present invention. Features and advantages of the present invention can be realized and obtained by the elements and combinations specifically pointed out in the appended application scope. These and other features of the present invention will become more clearly understood according to the following description and the appended claims, or can be understood by the implementation of the embodiments described in the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0043] Figure 1 The present invention is a circuit diagram of a model prediction PI control circuit for improving the dynamic performance of a converter.

[0044] Figure 2a It is a key waveform diagram of the dual phase-shift DAB converter in different working modes in the example of the present invention.

[0045] Figure 2b It is a distribution diagram of internal and external phase shift angle trajectories under different working modes of the dual phase shift DAB converter in the example of the present invention.

[0046] Figure 3 It is a flow chart of the model prediction PI control method for improving the dynamic performance of the converter of the present invention.

[0047] Figure 4a is the battery voltage V in the present embodimentbat =250V, the dynamic response waveform of the dual phase-shifted DAB converter to battery charging and discharging;

[0048] Figure 4b is the battery voltage V in the present embodiment bat =450V, the dynamic response waveform of the dual phase-shifted DAB converter to battery charging and discharging;

[0049] Figure 5 It is a principle block diagram of a model prediction PI control system for improving the dynamic performance of a converter in an embodiment of the present invention. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and beneficial technical effect of the present invention clearer, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. It should be understood that the specific implementation methods described in this specification are only for explaining the present invention, not for limiting the present invention.

[0051] It should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0052] It should also be noted that, unless otherwise clearly specified and limited, the terms such as "install", "connect", "connect", "fix", "set" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be determined according to the specific circumstances.

[0053] See also Figures 1 to 3 The present invention provides a model prediction PI control method for improving the dynamic performance of a (double phase shift DAB) converter, comprising the following steps:

[0054] S1: Detect the actual voltage V1 on the input bus side, the actual voltage V2 on the battery side, and the battery charge and discharge current I bat ;

[0055] S2: The actual voltage V1 on the bus side, the actual voltage V2 on the battery side and the current reference command value I refThe initial outward phase angle within the control beat is calculated in the PI controller of the input prediction model

[0056] S3: Set the current command I ref and the actual detected battery charge and discharge current I bat The current error signal e is obtained by subtracting i And input to the PI controller G ic The external phase angle increment within this control beat is obtained

[0057] S4: Initial external phase angle and the external phase angle increment The summation gives the actual output external phase angle within this control beat. According to the actual output external phase shift angle The actual voltage V1 and the actual voltage V2 on the battery side are detected to determine the working mode of the dual phase-shift DAB converter at this time, and output the internal phase shift angle under the corresponding working mode.

[0058] S5: The calculated external phase angle and internal phase angle Input to the DPWM pulse generation module to generate a drive pulse signal to control the battery charge and discharge current I bat The current reference command value I issued by the fast follow-up response ref .

[0059] In a preferred embodiment, the calculation process of the PI controller of the prediction model described in step S2 is:

[0060]

[0061] In the above formula (1), L is the power inductance value, f s is the switching frequency and N is the transformer ratio.

[0062] In a preferred embodiment, the dual phase shift DAB converter is based on the external phase shift angle The working mode is specifically divided into working mode A and working mode B according to the relationship between the actual voltage V1 and the actual voltage V2 on the battery side. The determination basis of the working mode A and the working mode B is:

[0063]

[0064] In the above formula (2), the voltage ratio m=NV2 / V1.

[0065] In a preferred embodiment, the internal phase shift angle in the corresponding working mode described in step S4 is The calculation process is:

[0066]

[0067] A dual phase-shifted DAB converter charging and discharging operation platform was built on the MATLAB / Simulink simulation platform, with the parameters as shown in the above example. bat =250V, the dynamic response waveform of the system using traditional PI control and model prediction PI control method is as follows Figure 4a As shown, the specific variables include the external shift phase angle Battery current I bat . The battery current I bat It can be seen from the enlarged waveform that under the traditional PI control scheme, when the current command I ref When switching from 80A to 120A, the battery current response time is about 3.5ms, and the overshoot is as high as 29%; the current command I ref When switching from 120A to 80A, the current response time is about 3.6ms, and the overshoot is as high as 26%. After adopting the model prediction PI control method, when the current command I ref When switching from 80A to 120A, the battery current response time is about 2.1ms, without overshoot; the current command I ref When switching from 120A to 80A, the current response time is about 2.2ms, and there is no overshoot. Figure 4b As shown, when the battery voltage increases to V bat =450V, the model predictive PI control method is used. When the current command I ref When switching between 80A and 120A, the battery current response time is approximately 2.3ms with no overshoot.

[0068] Depend on Figure 4a and Figure 4b The results show that the model prediction PI control method disclosed in the present invention can improve the dynamic response speed of the dual phase-shifted DAB converter, and the overshoot is significantly suppressed. In addition, the method can maintain excellent dynamic performance under various working conditions.

[0069] The present invention also provides a model prediction PI control circuit for improving the dynamic performance of a dual phase-shift converter, comprising: a DC power supply, a dual phase-shift (DAB) converter, a battery and a digital control system; the DC power supply is electrically connected to the dual phase-shift DAB converter, the dual phase-shift DAB converter is electrically connected to the battery, and the digital control system is electrically connected to the dual phase-shift DAB converter and the battery.

[0070] Specifically, the dual phase shift (DAB) converter includes a capacitor C1, a MOS transistor Q1, a MOS transistor Q2, a MOS transistor Q3, a MOS transistor Q4, a MOS transistor Q5, a MOS transistor Q6, a MOS transistor Q7, a MOS transistor Q8, a high frequency transformer T r , Excitation inductance L m , output filter capacitor C f And the output filter inductor L f ;

[0071] One end of the capacitor C1 is electrically connected to the positive electrode of the DC power supply, the drain of the MOS transistor Q1 and the drain of the MOS transistor Q3, and the other end of the capacitor C1 is electrically connected to the negative electrode of the DC power supply, the source of the MOS transistor Q2 and the source of the MOS transistor Q4. The source of the MOS transistor Q1 is electrically connected to the drain of the MOS transistor Q2, and the source of the MOS transistor Q3 is electrically connected to the drain of the MOS transistor Q4.

[0072] The excitation inductance L m One end of the excitation inductor L is electrically connected to the source of the MOS tube Q1. m The other end is connected to the high frequency transformer T r One end of the primary winding is electrically connected to the high frequency transformer T r The other end of the primary winding is electrically connected to the drain of the MOS tube Q4.

[0073] The source of the MOS transistor Q5 is electrically connected to the drain of the MOS transistor Q6, and the drain of the MOS transistor Q5 is electrically connected to the drain of the MOS transistor Q7 and the output filter capacitor C f One end of the output filter inductor L f The source of the MOS tube Q6 is electrically connected to the source of the MOS tube Q8 and the output filter capacitor C f The other end is electrically connected to the negative pole of the battery, and the output filter inductor L f The other end of is electrically connected to the positive electrode of the battery, the source of the MOS tube Q5 is electrically connected to the drain of the MOS tube Q6, the source of the MOS tube Q7 is electrically connected to the drain of the MOS tube Q8,

[0074] The high frequency transformer T r One end of the secondary winding is electrically connected to the source of the MOS tube Q5, and the high-frequency transformer T r The other end of the secondary winding is electrically connected to the drain of the MOS tube Q8. Among them, the MOS tubes Q1 to Q4 form a full-bridge inverter circuit, the MOS tubes Q5 to Q8 form a full-bridge rectifier circuit, and the high-frequency transformer T r The excitation inductance L m The transformation ratio is N:1.

[0075] Specifically, the digital control system includes a prediction model, a PI controller, a dual phase shift control unit and a DPWM pulse generation module which are electrically connected in sequence, the prediction model is electrically connected to the battery, the output filter inductor L f The PI controller is electrically connected to form a difference module, and the DPWM pulse generation module is electrically connected to the MOS tubes Q1-Q8.

[0076] According to the output external phase angle and internal phase angle The driving pulse signals g1 to g8 of the MOS tubes Q1 to Q8 are generated respectively. By adjusting the phase relationship of the driving pulse signals g1 to g8 of the MOS tubes Q1 to Q8 in the dual phase-shift DAB converter, the bidirectional flow of energy of the dual phase-shift DAB converter and the dynamic adjustment of the charge and discharge current can be realized, and the battery can be charged and discharged.

[0077] During normal operation, the actual voltage V1 on the bus side, the actual voltage V2 on the battery side, and the battery charge and discharge current I bat The external phase shift angle of the double phase-shifted DAB converter is dynamically generated by inputting it into the PI controller of the proposed prediction model. and internal phase angle The DPWM pulse generation module outputs the corresponding driving pulse signals g1 to g8 to realize the battery charging and discharging current I bat For current command I ref Fast follow response.

[0078] According to another aspect of the present invention, Figure 5 As shown, a model prediction PI control system for improving the dynamic performance of a dual phase shift converter is provided, comprising: a detection module 501, a difference module 502, an input module 503 and a control module 504, wherein the detection module 501, the difference module 502, the input module 503 and the control module 504 are electrically connected to each other;

[0079] The detection module 501 is used to detect the actual voltage V1 on the input bus side, the actual voltage V2 on the battery side, and the battery charge and discharge current I bat The actual voltage V1, the actual voltage V2 on the battery side and the battery charge and discharge current I bat Input to the PI controller of the prediction model, the battery current I bat Input to the difference module;

[0080] The difference module 502 is used to convert the reference output current reference command value I ref and battery charge and discharge current I bat The current error signal e is obtained by subtracting i ;

[0081] The calculation module 503 is used to calculate the initial external phase angle of the PI controller in this control beat. Outward phase angle increment And the actual output external phase shift angle And calculate the internal phase angle under the corresponding working mode (working mode A, working mode B)

[0082] The control module 504 is used to use the calculated external phase shift angle And the corresponding internal phase angle A driving pulse signal is obtained to quickly follow and respond to the current instruction of the charging and discharging system.

[0083] According to another aspect of the present invention, a non-transitory computer-readable storage medium is provided, on which a computer program is stored, and the computer program is executed by a processor to implement the steps of a model predictive PI control method for improving the dynamic performance of a dual phase-shifted converter.

[0084] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0085] In particular, according to some embodiments of the present disclosure, the process described above can be implemented as a computer software program. For example, some embodiments of the present disclosure include a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program contains program code for executing the method shown in the flowchart. In some such embodiments, the computer program can be downloaded and installed from a network through a communication device, or installed from a storage device, or installed from a ROM. When the computer program is executed by a processing device, the above-mentioned functions defined in the method of some embodiments of the present disclosure are executed.

[0086] It should be noted that the computer-readable medium recorded in some embodiments of the present disclosure may be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In some embodiments of the present disclosure, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, device or device. In some embodiments of the present disclosure, a computer-readable signal medium may include a mission data signal propagated in a baseband or as part of a carrier wave, which carries a computer-readable program code. This propagated mission data signal may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The computer readable signal medium may also be any computer readable medium other than a computer readable storage medium, which may send, propagate or transmit a program for use by or in conjunction with an instruction execution system, apparatus or device. The program code contained on the computer readable medium may be transmitted using any suitable medium, including but not limited to: wires, optical cables, RF (radio frequency), etc., or any suitable combination of the above.

[0087] In some embodiments, the client and the server may communicate using any currently known or future developed network protocol such as HTTP (HyperTextTransferProtocol), and may be interconnected with any form or medium of digital task data communication (e.g., a communication network). Examples of communication networks include a local area network ("LAN"), a wide area network ("WAN"), an internet (e.g., the Internet), and a peer-to-peer network (e.g., an adhoc peer-to-peer network), as well as any currently known or future developed network.

[0088] The computer-readable medium may be included in the electronic device, or may exist independently without being incorporated into the electronic device. The computer-readable medium carries one or more programs. When the one or more programs are executed by the electronic device, the electronic device: in response to detecting a query operation on a production collaboration document in a switch production line management application, determines the network connection status of the switch production line management application; in response to determining that the network connection status of the switch production line management application represents an offline state, replaces the web page entry information corresponding to the production collaboration document with target entry file information, and loads target web page resource information to display the web page of the production collaboration document offline in the switch production line management application, wherein the target entry file information is file information of a pre-downloaded entry file corresponding to the web page of the production collaboration document, and the target web page resource information is locally stored resource information corresponding to the web page; in response to determining that the network connection status of the switch production line management application represents an online state, and the web page resource information corresponding to the production collaboration document is not stored locally, downloads the web page resource information of the web page from the production line document server, wherein the web page resource information includes an entry file and resource information; according to the web page resource information, displays the web page of the production collaboration document in the switch production line management application, and stores the web page resource information in a local database.

[0089] Computer program code for performing the operations of some embodiments of the present disclosure may be written in one or more programming languages ​​or a combination thereof, including product-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0090] The present invention is not limited to what is described in the specification and implementation modes, and therefore additional advantages and modifications can be easily realized by those skilled in the art. Therefore, without departing from the spirit and scope of the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details, representative devices, and illustrative examples shown and described herein.

Claims

1. A model predictive PI control method for improving the dynamic performance of a converter, characterized in that: The steps include: S1: Detect the actual voltage V1 on the input bus side, the actual voltage V2 on the battery side, and the battery charge and discharge current I bat ; S2: The actual voltage V1 on the bus side, the actual voltage V2 on the battery side and the current reference command value I ref The initial outward phase angle within the control beat is calculated in the PI controller of the input prediction model S3: Set the current command I ref and the actual detected battery charge and discharge current I bat The current error signal e is obtained by subtracting i And input to the PI controller G ic The external phase angle increment within this control beat is obtained S4: Initial external phase angle and the external phase angle increment The summation gives the actual output external phase angle within this control beat. According to the actual output external phase shift angle The actual voltage V1 and the actual voltage V2 on the battery side are detected to determine the working mode of the dual phase-shift DAB converter at this time, and output the internal phase shift angle under the corresponding working mode. S5: The calculated external phase angle and internal phase angle Input to the DPWM pulse generation module to generate a drive pulse signal to control the battery charge and discharge current I bat The current reference command value I issued by the fast follow-up response ref .

2. The model predictive PI control method for improving the dynamic performance of the converter according to claim 1, characterized in that: The calculation process of the PI controller of the prediction model described in step S2 is: In the above formula (1), L is the power inductance value, f s is the switching frequency and N is the transformer ratio.

3. The model predictive PI control method for improving the dynamic performance of the converter according to claim 2, characterized in that: The double phase shift DAB converter in step S4 is based on the external phase shift angle The working mode is specifically divided into working mode A and working mode B according to the relationship between the actual voltage V1 and the actual voltage V2 on the battery side. The determination basis of the working mode A and the working mode B is: In the above formula (2), the voltage ratio m=NV2 / V1.

4. The model predictive PI control method for improving the dynamic performance of a converter according to claim 2, characterized in that: The internal phase shift angle in the corresponding working mode described in step S4 The calculation process is:

5. A model prediction PI control circuit for improving the dynamic performance of a converter as claimed in any one of claims 1 to 4, characterized in that: include: A DC power supply, a dual phase-shift DAB converter, a battery and a digital control system; the DC power supply is electrically connected to the dual phase-shift DAB converter, the dual phase-shift DAB converter is electrically connected to the battery, and the digital control system is electrically connected to the dual phase-shift DAB converter and the battery.

6. The model prediction PI control circuit for improving the dynamic performance of the converter according to claim 5, characterized in that: The dual phase shift converter includes a capacitor C1, a MOS transistor Q1, a MOS transistor Q2, a MOS transistor Q3, a MOS transistor Q4, a MOS transistor Q5, a MOS transistor Q6, a MOS transistor Q7, a MOS transistor Q8, a high frequency transformer T r , Excitation inductance L m , output filter capacitor C f And the output filter inductor L f ; One end of the capacitor C1 is electrically connected to the positive electrode of the DC power supply, the drain of the MOS transistor Q1 and the drain of the MOS transistor Q3, and the other end of the capacitor C1 is electrically connected to the negative electrode of the DC power supply, the source of the MOS transistor Q2 and the source of the MOS transistor Q4. The source of the MOS transistor Q1 is electrically connected to the drain of the MOS transistor Q2, and the source of the MOS transistor Q3 is electrically connected to the drain of the MOS transistor Q4. The excitation inductance L m One end of the excitation inductor L is electrically connected to the source of the MOS tube Q1. m The other end is connected to the high frequency transformer T r One end of the primary winding is electrically connected to the high frequency transformer T r The other end of the primary winding is electrically connected to the drain of the MOS tube Q4. The source of the MOS transistor Q5 is electrically connected to the drain of the MOS transistor Q6, and the drain of the MOS transistor Q5 is electrically connected to the drain of the MOS transistor Q7 and the output filter capacitor C f One end of the output filter inductor L f The source of the MOS tube Q6 is electrically connected to the source of the MOS tube Q8 and the output filter capacitor C f The other end is electrically connected to the negative pole of the battery, and the output filter inductor L f The other end of is electrically connected to the positive electrode of the battery, the source of the MOS tube Q5 is electrically connected to the drain of the MOS tube Q6, the source of the MOS tube Q7 is electrically connected to the drain of the MOS tube Q8, The high frequency transformer T r One end of the secondary winding is electrically connected to the source of the MOS tube Q5, and the high-frequency transformer T r The other end of the secondary winding is electrically connected to the drain of the MOS tube Q8.

7. The model prediction PI control circuit for improving the dynamic performance of the converter according to claim 5, characterized in that: The digital control system includes a prediction model, a PI controller, a dual phase shift control unit and a DPWM pulse generation module which are electrically connected in sequence. The prediction model is electrically connected to the battery. The output filter inductor L f The PI controller is electrically connected to form a difference module, and the DPWM pulse generation module is electrically connected to the MOS tubes Q1-Q8.

8. A model predictive PI control system for improving the dynamic performance of a converter as claimed in any one of claims 1 to 4, characterized in that: include: A detection module (501), a differential module (502), an input module (503) and a control module (504), wherein the detection module (501), the differential module (502), the input module (503) and the control module (504) are electrically connected to each other; The detection module (501) is used to detect the actual voltage V1 on the input bus side, the actual voltage V2 on the battery side and the battery charge and discharge current I bat The actual voltage V1, the actual voltage V2 on the battery side and the battery charge and discharge current I bat Input to the PI controller of the prediction model, the battery current I bat Input to the difference module; A difference module (502) is used to convert the reference output current reference command value I ref and battery charge and discharge current I bat The current error signal e is obtained by subtracting i ; The calculation module (503) is used to calculate the initial external phase angle of the PI controller in this control beat. Outward phase angle increment And the actual output external phase shift angle And calculate the internal phase shift angle in the corresponding working mode A control module (504) is used to use the calculated external phase shift angle And the corresponding internal phase angle A driving pulse signal is obtained to quickly follow and respond to the current instruction of the charging and discharging system.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: The computer program is executed by a processor to implement the steps of the model predictive PI control method for improving the dynamic performance of the converter as described in any one of claims 1 to 4.

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