Ice melting method, device, equipment, medium and program for dual-active full-bridge converter

Abstract

The invention relates to an ice melting method and device for a dual-active full-bridge converter, computer equipment, a computer readable storage medium and a computer program product. The method comprises the steps of obtaining a target power per unit value of the dual-active full-bridge converter to determine a current power mode of the dual-active full-bridge converter under the condition that the dual-active full-bridge converter is iced, and obtaining a phase shift ratio calculation strategy corresponding to the power mode, according to a phase shift ratio calculation strategy, the target power per unit value and the voltage transmission ratio of the dual-active full-bridge converter, calculating a first phase shift ratio of a primary side full bridge and a second phase shift ratio of a secondary side full bridge of the dual-active full-bridge converter, and generating a pulse width modulation signal based on the first phase shift ratio and the second phase shift ratio to control a switching tube of the dual-active full-bridge converter, and melting the icing through heat energy generated by the dual-active full-bridge converter. By adopting the method, the electric energy transmission efficiency of the converter can be improved in the ice coating process of the dual-active full-bridge converter.

Description

Technical Field

[0001] The present application relates to the technical field of electric power, and particularly to an ice melting method, device, computer device, computer-readable storage medium and computer program product for a dual active full bridge converter. Background Art

[0002] With the development of electric power technology, the demand for electric energy is also increasing. In order to enable more users to use stable electric energy, the demand for power transmission equipment and substation equipment is also continuously increasing. However, outdoor equipment is easily affected by bad weather. Taking substation equipment as an example, as a kind of substation equipment, the converter will be covered with ice due to rain and snow weather. Excessive icing will affect the equipment safety and further affect the electric energy transmission.

[0003] In the traditional technology, usually the way of directly increasing the power of the converter manually is adopted to melt the ice by the thermal effect of the current. However, this way is subject to manual experience and has the problem of excessive electric energy loss, which affects the electric energy transmission efficiency of the converter. Summary of the Invention

[0004] Based on this, it is necessary to provide an ice melting method, device, computer device, computer-readable storage medium and computer program product for a dual active full bridge converter, which can improve the electric energy transmission efficiency of the converter during the ice melting process of the dual active full bridge converter.

[0005] In a first aspect, the present application provides an ice melting method for a dual active full bridge converter, including: when there is ice on the dual active full bridge converter, obtaining the per-unit value of the target power of the dual active full bridge converter; determining the current power mode of the dual active full bridge converter according to the per-unit value of the target power, and obtaining the phase shift ratio calculation strategy corresponding to the power mode; calculating a first phase shift ratio of the primary side full bridge and a second phase shift ratio of the secondary side full bridge of the dual active full bridge converter according to the phase shift ratio calculation strategy, the per-unit value of the target power and the voltage transfer ratio of the dual active full bridge converter; generating a pulse width modulation signal based on the first phase shift ratio and the second phase shift ratio, and controlling the duty cycle of the switching tubes of the primary side full bridge and the duty cycle of the switching tubes of the secondary side full bridge according to the pulse width modulation signal, so as to melt the ice by the heat energy generated by the dual active full bridge converter.

[0006] In one embodiment, according to the phase shift ratio calculation strategy, the per-unit value of the target power, and the voltage transfer ratio of the dual-active-bridge converter, calculating the first phase shift ratio of the full-bridge on the primary side and the second phase shift ratio of the full-bridge on the secondary side of the dual-active-bridge converter includes: extracting the first phase shift ratio expression and the second phase shift ratio expression included in the phase shift ratio calculation strategy; calculating the first phase shift ratio according to the first phase shift ratio expression, the per-unit value of the target power, and the voltage transfer ratio, and calculating the second phase shift ratio according to the second phase shift ratio expression, the per-unit value of the power, and the voltage transfer ratio.

[0007] In one embodiment, the generation process of the first phase shift ratio expression and the second phase shift ratio expression includes: obtaining the per-unit value of the actual power and the per-unit value of the actual inductor current of the current power mode of the dual-active-bridge converter; solving for the phase shift ratio according to the preset constraint conditions and the Lagrangian function to obtain the first phase shift ratio expression and the second phase shift ratio expression, where the constraint conditions include that the per-unit value of the actual power is equal to the per-unit value of the target power and the per-unit value of the actual inductor current is minimized.

[0008] In one embodiment, obtaining the per-unit value of the actual power and the per-unit value of the actual inductor current of the current power mode of the dual-active-bridge converter includes: obtaining the actual inductor current corresponding to multiple level conversion moments within a modulation period of the dual-active-bridge converter; obtaining the peak value of the actual inductor current and the actual transmitted power in the current power mode of the dual-active-bridge converter based on each actual inductor current, the first unknown parameter corresponding to the first phase shift ratio, and the second unknown parameter corresponding to the second phase shift ratio; obtaining the per-unit value of the actual power based on the actual transmitted power and the reference power, and obtaining the per-unit value of the actual inductor current based on the peak value and the reference current, where the reference power is the upper limit transmitted power of the dual-active-bridge converter under the single-phase-shift modulation strategy, and the reference current is the inductor current corresponding to the upper limit transmitted power.

[0009] In one embodiment, determining the current power mode of the dual-active-bridge converter according to the per-unit value of the target power and obtaining the phase shift ratio calculation strategy corresponding to the power mode includes: if the per-unit value of the target power is greater than the power upper limit threshold of the first power mode, determining that the power mode of the dual-active-bridge converter is the second power mode and obtaining the phase shift ratio calculation strategy corresponding to the second power mode; if the per-unit value of the target power is less than the power upper limit threshold of the first power mode, determining that the power mode of the dual-active-bridge converter is the first power mode and obtaining the phase shift ratio calculation strategy corresponding to the first power mode.

[0010] In one embodiment, the method further includes: if the per-unit value of the target power is greater than the power upper limit threshold of the second power mode, generating a target pulse width modulation signal based on a single-phase-shift modulation strategy; and controlling the duty cycle of the switching tubes of the primary full-bridge and the duty cycle of the switching tubes of the secondary full-bridge according to the target pulse width modulation signal, so as to melt the ice covering through the heat energy generated by the dual-active-bridge converter.

[0011] In one embodiment, obtaining the per-unit value of the target power of the dual-active-bridge converter includes: obtaining the temperature and humidity data of a temperature and humidity sensor, and generating the per-unit value of the target power according to the temperature and humidity data when the temperature and humidity data exceed the ice-covering threshold of the dual-active-bridge converter; or obtaining a preset output voltage input externally and the actual output voltage of the dual-active-bridge converter, calculating the difference between the actual output voltage and the preset output voltage, and generating the per-unit value of the target power based on the difference through a proportional-integral regulator.

[0012] In a second aspect, the present application further provides an ice-melting device for a dual-active-bridge converter, including: a per-unit value acquisition module of the target power, configured to obtain the per-unit value of the target power of the dual-active-bridge converter when there is ice covering on the dual-active-bridge converter; a phase-shift ratio calculation strategy acquisition module, configured to determine the current power mode of the dual-active-bridge converter according to the per-unit value of the target power, and obtain the phase-shift ratio calculation strategy corresponding to the power mode; a phase-shift ratio calculation module, configured to calculate a first phase-shift ratio of the primary full-bridge of the dual-active-bridge converter and a second phase-shift ratio of the secondary full-bridge according to the phase-shift ratio calculation strategy, the per-unit value of the target power, and the voltage transfer ratio of the dual-active-bridge converter; and a converter control module, configured to generate a pulse width modulation signal based on the first phase-shift ratio and the second phase-shift ratio, and control the duty cycle of the switching tubes of the primary full-bridge and the duty cycle of the switching tubes of the secondary full-bridge according to the pulse width modulation signal, so as to melt the ice covering through the heat energy generated by the dual-active-bridge converter.

[0013] In a third aspect, the present application further provides a computer device, including a memory and a processor, where the memory stores a computer program, and when the processor executes the computer program, the steps of the method described in the first aspect are implemented.

[0014] In a fourth aspect, the present application further provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the method described in the first aspect are implemented.

[0015] In a fifth aspect, the present application further provides a computer program product, including a computer program, and when the computer program is executed by a processor, the steps of the method described in the first aspect are implemented.

[0016] The ice melting method, device, computer equipment, computer-readable storage medium and computer program product of the above-mentioned dual-active full-bridge converter, in the case of icing on the dual-active full-bridge converter, obtain the per-unit value of the target power of the dual-active full-bridge converter, determine the current power mode of the dual-active converter according to the per-unit value of the target power and obtain the phase-shift ratio calculation strategy corresponding to the power mode. At different powers, configure different phase-shift ratios to maintain better transmission efficiency. Calculate the first phase-shift ratio of the primary-side full-bridge and the second phase-shift ratio of the secondary-side full-bridge of the dual-active full-bridge converter according to the per-unit value of the target power and the voltage transfer ratio of the dual-active full-bridge circuit according to the phase-shift ratio calculation strategy. Generate a pulse width modulation signal based on the first phase-shift ratio and the second phase-shift ratio, and control the duty cycle of the switching tubes of the primary-side full-bridge and the secondary-side full-bridge according to the pulse width modulation signal. While melting the ice by the heat energy generated by the dual-active full-bridge converter when increasing the power, keep a better phase-shift ratio for the dual-active full-bridge converter, thereby improving the power transmission efficiency of the dual-active full-bridge converter. Description of the Drawings

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments of the present application or related technologies. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0018] Figure 1 It is an application environment diagram of the ice melting method of the dual-active full-bridge converter in an embodiment;

[0019] Figure 2 It is a schematic flowchart of the ice melting method of the dual-active full-bridge converter in an embodiment;

[0020] Figure 3 It is a schematic diagram of the dual-active full-bridge converter in an embodiment;

[0021] Figure 4 It is a schematic diagram of the experimental environment of the signal modulation of the dual-active full-bridge converter in an embodiment;

[0022] Figure 5 It is a schematic diagram of the modulation strategy waveform of the dual-active full-bridge converter in an embodiment;

[0023] Figure 6 It is a schematic diagram of the modulation strategy waveform of another dual-active full-bridge converter in an embodiment;

[0024] Figure 7 It is a schematic flowchart of step 201 in an embodiment;

[0025] Figure 8It is a schematic flowchart of step 201 in another embodiment;

[0026] Figure 9 It is a schematic flowchart of step 202 in one embodiment;

[0027] Figure 10 It is a schematic diagram of a width pulse modulation signal in one embodiment;

[0028] Figure 11 It is a schematic flowchart of the calculation process of the actual power per unit value and the actual inductance per unit value in one embodiment;

[0029] Figure 12 It is a schematic flowchart of the generation process of the first phase shift expression and the second phase shift expression in one embodiment;

[0030] Figure 13 It is a schematic flowchart of step 203 in one embodiment;

[0031] Figure 14 It is a schematic flowchart of generating a target pulse width modulation signal based on a single-phase shift modulation strategy in one embodiment;

[0032] Figure 15 It is a schematic diagram of the transmission power surface diagram of a dual-active full-bridge circuit under a width pulse modulation signal in one embodiment;

[0033] Figure 16 It is a schematic diagram of the peak-to-peak characteristic surface diagram of the inductor current of a dual-active full-bridge circuit under a width pulse modulation signal in one embodiment;

[0034] Figure 17 It is a schematic diagram of the power range of the power mode of a dual-active full-bridge circuit in one embodiment;

[0035] Figure 18 It is a schematic flowchart of the ice melting method of a dual-active full-bridge converter in another embodiment;

[0036] Figure 19 It is a structural block diagram of the ice melting device of a dual-active full-bridge converter in one embodiment;

[0037] Figure 20 It is an internal structure diagram of a computer device in one embodiment. Specific embodiments

[0038] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0039] It should be noted that the terms "first", "second", etc. used in this application can be used to describe various components, but these components are not limited by these terms. These terms are only used to distinguish the first component from the second component. The terms "including" and "having" used in this application, and any variations thereof, are intended to cover non-exclusive inclusion. The term "plurality" used in this application refers to two or more. The term "and / or" used in this application refers to one of the solutions or any combination of multiple solutions.

[0040] The ice melting method of the dual active full-bridge converter provided by the embodiment of this application can be applied to, for example, Figure 1 the application environment shown, and this application environment includes at least a server 101 and a dual active full-bridge (DAB) converter 102.

[0041] Among them, the server 101 is used to obtain the per-unit value of the target power of the dual active full-bridge converter and determine the current power mode of the dual active full-bridge converter 102 when the dual active full-bridge converter 102 is iced. According to the phase shift ratio calculation strategy corresponding to the power mode, the per-unit value of the target power, and the voltage conversion ratio of the dual active full-bridge converter 102, calculate the first phase shift ratio of the primary-side full-bridge and the second phase shift ratio of the secondary-side full-bridge of the dual active full-bridge converter 102, generate a pulse width modulation signal based on the first phase shift ratio and the second phase shift ratio, and control the duty cycle of the switching tubes of the dual active full-bridge converter 102 according to the pulse width modulation signal, and melt the ice through the heat energy generated by the dual active full-bridge converter 102. The server 101 can communicate with the dual active full-bridge converter 102 through a network. The server 101 can be an independent physical server, or a server cluster or distributed system composed of multiple physical servers, or a cloud server providing cloud computing services.

[0042] The dual active full-bridge converter 102 is used to receive the pulse width modulation signal sent by the server 101 or the control signal generated based on the pulse width modulation signal, control the switching tubes of the primary-side full-bridge and the secondary-side full-bridge according to the pulse width modulation signal or the control signal, and increase the output power by controlling the switching tubes to generate more heat energy to melt the ice. The dual active full-bridge converter 102 can be a transformer, or a component of a transformer, or a hardware module of a transformer.

[0043] In an exemplary embodiment, as Figure 2 shown, an ice melting method of a dual active full-bridge converter is provided. Taking the server in Figure 1 as an example, the following steps 201 to step 204 are included.

[0044] Step 201, obtain the per-unit value of the target power of the dual active full-bridge converter.

[0045] In practical applications, the transmission of electric energy is usually carried out using ultra-high voltage direct current. For ultra-high voltage direct current, voltage conversion is required during use. The voltage conversion can be achieved through a dual-active full-bridge converter. However, outdoor converters are prone to icing in bad weather. In view of this, in this application, the power of the dual-active full-bridge converter is increased by increasing the power, and de-icing is carried out through the current thermal effect.

[0046] During the implementation process, when it is detected that the dual-active full-bridge converter is iced, the external system can send the per-unit value of the target power to the server, and the server obtains the per-unit value of the target power of the dual-active full-bridge converter, or the server can also generate the per-unit value of the target power.

[0047] Among them, the per-unit value of the target power refers to the per-unit value of the target power that the dual-active full-bridge converter needs to increase to. The target power can be generated by the server and / or the external system, or directly input by the user; the per-unit value is a standardized representation method used to represent the ratio of an electrical quantity relative to a reference value, which can simplify calculations and eliminate the influence of units. The per-unit value of the target power is the per-unit value of the target power; optionally, the per-unit value of the target power is calculated based on the target power and the reference power; the reference power can be the maximum transmission power that the dual-active full-bridge converter can achieve under the single-phase-shift modulation strategy.

[0048] During the execution process, the server can obtain the per-unit value of the target power input by the external system. The external system can configure sensors. By detecting the sensor data of the sensors, it is detected that the dual-active full-bridge converter is iced. The external system can calculate the per-unit value of the target power according to the sensor data and send it to the server; or, the external system can also query the per-unit value of the target power corresponding to the sensor data in the data table according to the sensor data and send it to the server; in addition, the external system can also obtain the per-unit value of the target power input by the user through the terminal and send it to the server. The external system can be a proportional-integral regulator.

[0049] In addition, the server can also calculate the per-unit value of the target power according to the sensor data, or query the per-unit value of the target power corresponding to the sensor data, or obtain the per-unit value of the target power input by the user through the terminal.

[0050] Step 202: Determine the current power mode of the dual-active full-bridge converter according to the per-unit value of the target power, and obtain the phase-shift ratio calculation strategy corresponding to the power mode.

[0051] In an actual scenario, the dual-active full-bridge converter adjusts the power by adjusting the phase-shift ratio between the primary-side full bridge and the secondary-side full bridge; in this application, by configuring an asymmetric phase-shift ratio for the primary-side full bridge and the secondary-side full bridge of the dual-active full-bridge converter, while adjusting the output power of the dual-active full-bridge converter, the inductor current of the dual-active full-bridge converter is reduced, and the power transmission efficiency is improved.

[0052] During the implementation process, different power modes can be pre-configured, and a phase-shift ratio calculation strategy can be pre-configured for different power modes. At the same time, power modes corresponding to different target power per-unit values are configured to ensure the adaptability of the calculated phase-shift ratio to the target power per-unit value; the server can determine the current power mode of the dual-active full-bridge converter according to the target power per-unit value and query the phase-shift ratio calculation strategy corresponding to the current power mode.

[0053] Among them, the current power mode of the dual-active full-bridge converter refers to the power mode that matches the target power per-unit value, that is, the power mode that the dual-active full-bridge converter needs to change to. The power mode can configure different power per-unit value ranges, and the power mode of the dual-active full-bridge converter is determined according to the power range where the target power per-unit value is located; the phase-shift ratio calculation strategy can be a calculation method, or a calculation formula, or an algorithm for the first phase-shift ratio of the primary-side full bridge and the second phase-shift ratio of the secondary-side full bridge. That is, by inputting the input data into this algorithm, the first phase-shift ratio and the second phase-shift ratio can be obtained.

[0054] Step 203, calculate the first phase-shift ratio of the primary-side full bridge and the second phase-shift ratio of the secondary-side full bridge of the dual-active full-bridge converter according to the phase-shift ratio calculation strategy, the target power per-unit value, and the voltage transfer ratio of the dual-active full-bridge converter.

[0055] Among them, the primary-side full bridge of the dual-active full-bridge converter is a full-bridge inverter circuit connected to the power supply side in the dual-active full-bridge converter. The primary-side full bridge can include four switching tubes and can also include an auxiliary inductor. In this application, the inductor current of the auxiliary inductor is reduced by adjusting the phase-shift ratio; the secondary-side full bridge of the dual-active full-bridge converter refers to the full-bridge circuit connected to the secondary side of the transformer, which is used to convert the AC voltage transmitted through the dual-active full-bridge converter back to DC voltage and output.

[0056] For example, as Figure 3 shown, the DAB converter consists of two full-bridge conversion circuits, a high-frequency transformer, and an auxiliary inductor. U ab is the input AC voltage of the primary bridge of the transformer, U cd is the output AC voltage of the secondary bridge of the transformer, i Lis the inductor current. U1 is the input voltage of the converter, U2 is the output voltage of the converter, and n is the turns ratio of the transformer; the voltage transfer ratio is defined as k = U1 / nU2, Ts is the switching period of the converter, and T hs is half of the switching period, and the switching frequency is fs. The left side is the full-bridge on the primary side of the dual-active full-bridge converter, and the right side is the full-bridge on the secondary side of the dual-active full-bridge converter. S1, S2, S3, and S4 are the four switching transistors on the primary-side full-bridge, and S5, S6, S7, and S8 are the four switching transistors on the secondary-side full-bridge.

[0057] During the implementation process, according to the phase-shift ratio calculation strategy, the first phase-shift ratio of the primary-side full-bridge of the dual-active full-bridge converter is calculated based on the per-unit value of the target power and the voltage transfer ratio of the dual-active full-bridge converter, and the second phase-shift ratio of the secondary-side full-bridge is calculated according to the phase-shift ratio calculation strategy based on the per-unit value of the target power and the voltage transfer ratio of the dual-active full-bridge converter.

[0058] Among them, the first phase-shift ratio is used to characterize the phase difference between the switching transistors of the primary-side full-bridge, and the second phase-shift ratio is used to characterize the phase difference between the switching transistors of the secondary-side full-bridge. For example, as Figure 3 shown, the first phase-shift ratio (D1) represents the internal phase-shift ratio of the primary-side full-bridge, which is defined as the phase difference between switching transistors S1 and S4; the second phase-shift ratio (D2) represents the asymmetry inside the secondary-side full-bridge, which is defined as the phase difference generated between switching transistors S1 and S8 due to the duty cycle not being 50%. Based on D2, the conduction duty cycles of switching transistors S5 and S7 can be expressed as 0.5 + 0.25D2, and the conduction duty cycles of switching transistors S6 and S8 can be expressed as 0.5 - 0.25D2.

[0059] During the execution process, the calculation formula and / or regular expression of the first phase-shift ratio and the calculation formula and / or regular expression of the second phase-shift ratio included in the phase-shift ratio calculation strategy can be extracted, and the first phase-shift ratio and the second phase-shift ratio are calculated according to the calculation formula and / or regular expression based on the per-unit value of the target power and the voltage transfer ratio; the per-unit value of the target power and the voltage transfer ratio can also be input into the phase-shift ratio algorithm corresponding to the phase-shift ratio calculation strategy to obtain the output first phase-shift ratio and second phase-shift ratio, and this algorithm can be stored and used in the form of components and / or functional modules.

[0060] Step 204, generate a pulse-width modulation signal based on the first phase-shift ratio and the second phase-shift ratio, and control the duty cycles of the switching transistors of the primary-side full-bridge and the duty cycles of the switching transistors of the secondary-side full-bridge according to the pulse-width modulation signal, so as to melt the ice coating by the heat energy generated by the dual-active full-bridge converter.

[0061] Under the condition of icing on the dual-active full-bridge converter, this application effectively utilizes the thermal effect of current to melt ice by adjusting the power. While adjusting the power, the first phase-shift ratio of the primary-side full-bridge and the second phase-shift ratio of the secondary-side full-bridge are correspondingly adjusted. The power transmission power of the dual-active full-bridge converter is improved through the dual-parameter modulation strategy of asymmetric duty cycle.

[0062] Among them, the pulse-width modulation signal is a periodic digital signal, and the time ratio of its high level and low level (i.e., the duty cycle) is variable. The switching states of the switching tubes in the primary-side full-bridge and the secondary-side full-bridge of the dual-active full-bridge converter can be controlled by this digital signal.

[0063] During the implementation process, an asymmetric pulse-width modulation signal (PWM pulse) is generated according to the first phase-shift ratio and the second phase-shift ratio. The duty cycles of the switching tubes in the primary-side full-bridge and the secondary-side full-bridge of the dual-active full-bridge converter are controlled by the pulse-width modulation signal, and the ice and / or snow covering the dual-active full-bridge converter are melted by the heat energy generated by the dual-active full-bridge converter.

[0064] This embodiment also provides a set of experimental verification data, the experimental verification data of the dual-active full-bridge circuit controlled by the pulse-width modulation signal generated according to the first phase-shift ratio and the second phase-shift ratio. The peak value of the inductor current under the modulation method of this application is compared with the peak value of the inductor current under the single-phase-shift modulation strategy. The specific experimental results are shown in the following examples.

[0065] For example, as Figure 4 shown in the experimental environment, when the input voltage is 45V, the output voltage is 11.25V, and the output power is 25W, the output voltage is 11.25V (voltage conversion ratio k = 2, and n = 2), the load resistance is 5Ω, and the modulation strategy waveform is as Figure 5 shown. The peak-to-peak values of the current of SPS and the modulation method of this application are 7.83A and 6.82A respectively. The peak-to-peak value of the inductor current of the modulation method of this application is reduced by 12.9% compared with the SPS modulation.

[0066] Continuing with the experimental environment shown in the above example Figure 4 when the input voltage is 45V, the output voltage is 15V, and the output power is 25W, the output voltage is 15V (voltage conversion ratio k = 1.5, and n = 2), the load resistance is 9Ω, and the modulation strategy waveform is as Figure 6 shown. The peak-to-peak values of the current of SPS and the modulation method of this application are 6.10A and 5.31A respectively. The peak-to-peak value of the inductor current of the modulation method of this application is reduced by 12.95% compared with the SPS modulation.

[0067] In the ice melting method of the above-mentioned dual-active full-bridge converter, when the dual-active full-bridge converter is covered with ice, the per-unit value of the target power of the dual-active full-bridge converter is obtained. According to the per-unit value of the target power, the current power mode of the dual-active converter is determined, and the phase shift ratio calculation strategy corresponding to the power mode is obtained. At different powers, different phase shift ratios are configured to maintain better transmission efficiency. According to the per-unit value of the target power and the voltage transmission ratio of the dual-active full-bridge circuit, the first phase shift ratio of the primary-side full-bridge and the second phase shift ratio of the secondary-side full-bridge of the dual-active full-bridge converter are calculated according to the phase shift ratio calculation strategy. Based on the first phase shift ratio and the second phase shift ratio, a pulse width modulation signal is generated, and the switching tubes of the dual-active full-bridge converter are controlled by the modulation signal with asymmetric duty cycle, reducing the inductor current in the converter and avoiding power loss. According to the pulse width modulation signal, the duty cycles of the switching tubes of the primary-side full-bridge and the secondary-side full-bridge are controlled. While increasing the power to melt the ice through the heat generated by the dual-active full-bridge converter, the dual-active full-bridge converter maintains a better phase shift ratio, thereby improving the power transmission efficiency of the dual-active full-bridge converter and effectively utilizing the heat generated by the dual-active full-bridge converter.

[0068] Based on the above exemplary embodiment, the following provides a method for melting ice of a dual-active full-bridge converter in one or more exemplary embodiments. Taking the server in Figure 1 as an example for illustration, the specific contents are as follows.

[0069] In practical applications, the ice-covered situation of the dual-active full-bridge converter can be obtained through sensors, can be obtained through the sensor data of the temperature and humidity sensor, or can be obtained through the sensor data of the ice-covered sensor. During the execution process, the server can determine the per-unit value of the target power according to the sensor data. In an optional implementation manner provided by the present application, as Figure 7 shown, obtaining the per-unit value of the target power of the dual-active full-bridge converter includes step 701.

[0070] Step 701, obtain the temperature and humidity data of the temperature and humidity sensor. When the temperature and humidity data exceed the ice-covered threshold of the dual-active full-bridge converter, generate the per-unit value of the target power according to the temperature and humidity data.

[0071] During the implementation process, the server obtains the temperature and humidity data of the temperature and humidity sensor, determines the rain and snow situation of the external environment through the temperature and humidity data, detects whether the temperature and humidity data exceed the ice-covered threshold of the dual-active full-bridge converter. If so, generate the per-unit value of the target power according to the temperature and humidity data. If not, no processing is required.

[0072] During the process of obtaining the temperature and humidity data, the server can obtain the temperature and humidity data through the temperature and humidity sensor in the area where the dual-active full-bridge converter is located, or can obtain the temperature and humidity data in the area where the dual-active full-bridge converter is located through an external temperature and humidity system.

[0073] During the generation of the per-unit value of the target power, different thresholds can be set for the temperature and humidity data, and different per-unit values of the target power can be adapted according to different thresholds. Alternatively, an algorithm for converting the temperature and humidity data and the per-unit value of the target power can also be configured, and the temperature and humidity data are input into the conversion algorithm to obtain the per-unit value of the target power.

[0074] In an alternative embodiment provided by the present application, the per-unit value of the target power corresponding to the current environment is determined through the sensor data of the temperature and humidity sensor, which improves the effectiveness of power regulation and also improves the accuracy of the power regulation value. At the same time, through the cooperation of the temperature and humidity sensor and the server, the server can timely determine the icing state of the dual-active full-bridge converter and then increase the power, which improves the timeliness of power regulation and further improves the safety of the dual-active full-bridge converter and the power network.

[0075] In addition, the icing condition of the sensor can also be obtained through manual monitoring. When it is manually monitored that the dual-active full-bridge converter is iced, the preset output voltage of the dual-active full-bridge converter can be input into the server through the terminal, so as to increase the output power of the dual-active full-bridge converter by increasing the output voltage. The server generates the per-unit value of the target power according to the difference between the preset output voltage and the actual output voltage; in another alternative embodiment provided by the present application, as Figure 8 shown, obtaining the per-unit value of the target power of the dual-active full-bridge converter includes step 801.

[0076] Step 801, obtain the preset output voltage input externally and the actual output voltage of the dual-active full-bridge converter, calculate the difference between the actual output voltage and the preset output voltage, and generate the per-unit value of the target power based on the difference through a proportional-integral regulator.

[0077] Among them, the proportional-integral regulator is a feedback control loop component used to keep a certain variable in the system constant or track the desired set value, and the difference between the actual output voltage and the preset output voltage is used to track the per-unit value of the target power corresponding to the preset output voltage.

[0078] During the implementation process, the server obtains the actual output voltage of the dual-active full-bridge converter input by the terminal and / or an external system, calculates the difference by subtracting the actual output voltage from the preset output voltage, inputs the difference into the proportional-integral regulator, and obtains the per-unit value of the target power output by the proportional-integral regulator.

[0079] In an alternative embodiment provided by the present application, the per-unit value of the target power is generated by obtaining the preset voltage input externally, which reduces the calculation burden of manually calculating the per-unit value of the target power. The per-unit value of the target power is calculated through a proportional-integral regulator, which improves the calculation accuracy of the per-unit value of the target power and improves the power control accuracy.

[0080] This application configures multiple power modes for a dual-active full-bridge converter, configures a power adaptation range and a corresponding phase-shift ratio calculation strategy for each power mode, and manages the power adjustment of the dual-active full-bridge converter through the preset power modes, improving the power regulation efficiency. At the same time, by differentiating the power adaptation range, the reliability of the phase-shift ratio calculation is improved.

[0081] During the execution process, two power modes can be set. The two power modes can be respectively set as the first power mode (low power mode) and the second power mode (high power mode). A power upper limit threshold can be set for the low power mode, and a power upper limit threshold can be set for the high power mode. When the per-unit value of the target power is less than the upper limit threshold of the low power mode, it is determined that the power mode of the dual-active full-bridge converter is the first power mode. When the per-unit value of the target power is greater than the upper limit threshold of the low power mode and less than the upper limit threshold of the high power mode, it is determined that the power mode of the dual-active full-bridge converter is the second power mode. In an optional implementation provided by this application, as Figure 9 shown, step 202 includes step 901 and step 902.

[0082] Step 901, if the per-unit value of the target power is less than the power upper limit threshold of the first power mode, then it is determined that the power mode of the dual-active full-bridge converter is the first power mode, and the phase-shift ratio calculation strategy corresponding to the first power mode is obtained.

[0083] During the implementation process, the server can compare the per-unit value of the target power with the power upper limit threshold of the first power mode to detect whether the per-unit value of the target power is less than this power upper limit threshold. If it is less, it indicates that the phase-shift ratio calculation strategy of the first power mode is adapted to the per-unit value of the target power. Then it is determined that the power mode of the dual-active full-bridge converter is the first power mode, and the phase-shift ratio calculation strategy corresponding to the first power mode is obtained. Among them, the power upper limit threshold of the first power mode exists in the form of a per-unit value.

[0084] During the execution process, the power upper limit threshold of the first power mode can be determined according to the voltage transfer ratio of the dual-active full-bridge converter. The power upper limit threshold of the first power mode can be (k 2 - 1) / (4k 2 - 4k + 1).

[0085] Step 902, if the per-unit value of the target power is greater than the power upper limit threshold of the first power mode, then it is determined that the power mode of the dual-active full-bridge converter is the second power mode, and the phase-shift ratio calculation strategy corresponding to the second power mode is obtained.

[0086] During the implementation process, if the server detects that the per-unit value of the target power is greater than the power upper limit threshold of the first power mode, indicating that the phase shift ratio calculation strategy of the first power mode is not compatible with the per-unit value of the target power, then determine the power mode of the dual-active full-bridge converter as the second power mode, and obtain the phase shift ratio calculation strategy corresponding to the second power mode.

[0087] During the execution process, the power upper limit threshold of the second power mode can be determined according to the voltage transfer ratio of the dual-active full-bridge converter, and the power upper limit threshold of the second power mode can be (6k 2 -8k + 2) / (9k 2 -12k + 4).

[0088] Among them, the power upper limit threshold of the second power mode is greater than the power upper limit threshold of the first power mode.

[0089] An optional implementation manner provided by this application, by presetting two power modes and the phase shift ratio calculation strategies corresponding to each power mode, compares the per-unit value of the target power with the power upper limit threshold of the low-power mode, and selects the appropriate power mode and phase shift ratio calculation strategy based on the comparison result, improving the calculation efficiency of the phase shift ratio and at the same time improving the calculation accuracy of the phase shift ratio.

[0090] Based on the two power modes provided in the above embodiments, the following will elaborate on these two power modes in detail; among them, the low-power mode refers to the output power of the dual-active full-bridge converter being in a lower power range, which can be a power mode that converts high voltage to a lower voltage, and the high-power mode refers to the output power of the dual-active full-bridge converter being in a higher power range, which can be a power mode that converts high voltage to a higher voltage.

[0091] For example, as Figure 10 shown, the basis for distinguishing the low-power mode and the high-power mode can be the change moment sequence of the square-wave voltages Uab and Ucd within a switching period, where Uab changes at three moments D1T hs and T hs and (1 + D1)T hs while U cd changes at two moments D2T hs and (1 + 0.5D2)T hs Then, (a) is the low-power mode (the first power mode), Figure 10 and (b) is the high-power mode (the second power mode). Figure 10

[0092] ​For the calculation of the first phase shift ratio and the second phase shift ratio, the waveforms of the modulation signals of the two power modes can be analyzed in advance to obtain the first phase shift ratio expression corresponding to the first phase shift ratio and the second phase shift ratio expression corresponding to the second phase shift ratio. The first phase shift ratio and the second phase shift ratio can be converted into the form of unknown parameters and substituted into the expressions of the actual power and the actual inductor current for calculation. In an optional implementation manner provided by the present application, as Figure 11 shown, the calculation process of the per-unit value of the actual power and the per-unit value of the actual inductor of the current power mode of the dual-active full-bridge converter includes steps 1101 to 1103.

[0093] Step 1101: Obtain the actual inductor current corresponding to multiple level change moments within a modulation period of the dual-active full-bridge converter.

[0094] During the implementation process, the server can calculate the actual inductor current corresponding to multiple level change moments within a modulation period of the dual-active full-bridge converter according to the input voltage of the primary-side full bridge, the output voltage of the secondary-side full bridge, the turns ratio of the coil, and the inductor; alternatively, the server can also obtain the actual inductor current by sending the derivation of the expression by an external system and / or manually. Wherein, the actual inductor current can exist in the form of an expression.

[0095] For example, the actual inductor current of the dual-active full-bridge converter can be calculated with reference to formula (1):

[0096] (Formula 1);

[0097] Step 1102: Obtain the peak value of the actual inductor current and the actual transmitted power under the current power mode of the dual-active full-bridge converter according to each actual inductor current, the first unknown parameter corresponding to the first phase shift ratio, and the second unknown parameter corresponding to the second phase shift ratio.

[0098] During the implementation process, each level change moment can be calculated according to the first phase shift ratio of the primary-side full bridge and the second phase shift ratio of the secondary-side full bridge. Then, the first unknown parameter corresponding to the first phase shift ratio and the second unknown parameter corresponding to the second phase shift ratio can be substituted into each actual inductor current to obtain the peak value of the actual inductor current under the current power mode of the dual-active full-bridge converter, and the actual transmitted power under the current power mode of the dual-active full-bridge converter can be calculated through the peak value of the actual inductor current.

[0099] For example, set the first phase shift ratio as the first unknown parameter D1, set the second phase shift ratio as the second unknown parameter D2, and substitute D1 and D2 into formula (1) to obtain the following formula (2):

[0100] (Formula 2);

[0101] Further, the peak-to-peak value of the inductor current mainly characterizes the fluctuation range of the inductor current within a single operating cycle, that is, the difference between the maximum value and the minimum value of the current. The inductor current reaches its maximum value at time t3 and its minimum value at time t0. Therefore, the peak-to-peak values of the inductor current in the first power mode and the second power mode are the same, as shown in Equation (3):

[0102] (Equation 3);

[0103] Further, according to the calculation formula of the average transmission power, the transmission power formula (4) of the DAB converter in the first power mode and the transmission power formula (5) of the DAB converter in the second power mode can be obtained:

[0104] (Equation 4);

[0105] (Equation 5).

[0106] Step 1103: Obtain the per-unit value of the actual power based on the actual transmission power and the reference power, and obtain the per-unit value of the actual inductor current based on the peak value and the reference current.

[0107] In the implementation process, the per-unit value is the ratio of the actual value to the reference value. The per-unit value of the actual power is the ratio of the actual power to the reference power, and the per-unit value of the actual inductor current is the ratio of the actual inductor current to the reference inductor current. Among them, the reference power is the upper limit transmission power of the dual-active-bridge converter under the single-phase-shift modulation strategy, and the reference current is the inductor current corresponding to the upper limit transmission power.

[0108] Among them, the per-unit value of the actual power can be an expression containing the first phase-shift ratio and the second phase-shift ratio, and the per-unit value of the actual inductor current can also be an expression containing the first phase-shift ratio and the second phase-shift ratio; the first phase-shift ratio can be the first unknown parameter, and the second phase-shift ratio can be the second unknown parameter.

[0109] During the execution process, in order to reduce the computational complexity, when calculating the power and current stress, the per-unit value is used to carry out the calculation work. Using the per-unit value can standardize the parameters in different power ranges, and this operation greatly simplifies the comparison analysis and optimization adjustment of the parameters under different working conditions.

[0110] For example, select the maximum transmission power that the DAB converter can reach under the single-phase-shift modulation strategy, as shown in Equation (6), and the input current in this state as the reference value, as shown in Equation (7):

[0111] (Equation 6);

[0112] (Formula 7);

[0113] Further, the per-unit value of the actual power in the first power mode is obtained by dividing the expression of the above formula (4) by the expression of formula (6), as shown in formula (8). The per-unit value of the actual power in the second power mode is obtained by dividing the expression of the above formula (5) by the expression of formula (6), as shown in formula (9). The per-unit value of the actual inductor current is obtained by dividing the expression of the above formula (3) by the expression of formula (7), as shown in formula (10):

[0114] (Formula 8);

[0115] (Formula 9);

[0116] (Formula 10).

[0117] An optional implementation provided by this application calculates the per-unit value of the actual power and the per-unit value of the actual inductor current through the calculation of the unknown parameters corresponding to the phase shift ratio. The device can accurately perform calculations through the form of regular expressions, improving the accuracy of the calculations. At the same time, through the form of expressions, it is convenient for data storage and data management, improving the modulation efficiency of the dual-active full-bridge converter.

[0118] It should be noted that the above steps 1101 to 1103 can be executed by the server. After the server finishes the execution, the per-unit value of the actual power and the per-unit value of the actual inductor current are obtained. It can also be calculated by the user and / or an external system and then sent to the server after obtaining the per-unit value of the actual power and the per-unit value of the actual inductor current. This is not limited here.

[0119] During the execution process, in order to keep the inductor current at a relatively small value to reduce power loss and improve power transmission efficiency, the first phase-shift expression corresponding to the first phase-shift ratio and the second phase-shift expression corresponding to the second phase-shift ratio can be obtained through the constraint conditions of the inequality. In an optional implementation provided by this application, as Figure 12 shown, the generation process of the first phase-shift expression and the second phase-shift expression includes steps 1201 to 1202.

[0120] Step 1201, obtain the per-unit value of the actual power and the per-unit value of the actual inductor current of the current power mode of the dual-active full-bridge converter.

[0121] During the implementation process, obtain the expression of the per-unit value of the actual power stored in the server and the expression of the per-unit value of the actual inductor current; or, obtain the expression of the per-unit value of the actual power and the expression of the per-unit value of the actual inductor current that have been calculated and sent by an external system and / or user; or, query the expression of the per-unit value of the actual power and the expression of the per-unit value of the actual inductor current from an external database.

[0122] Step 1202: Solve for the phase shift ratio according to the preset constraint conditions and the Lagrangian function to obtain the first phase shift ratio expression and the second phase shift ratio expression.

[0123] During the implementation process, the optimization objective is positioned as the per-unit value of the true inductor current in the form of an inequality. By obtaining the optimal control parameter combination (the first phase shift ratio and the second phase shift ratio), the peak-to-peak value of the inductor current is optimized to be minimized when the transmission power is a fixed value; among them, the constraint conditions include that the per-unit value of the actual power is equal to the per-unit value of the target power, and the per-unit value of the actual inductor current is the smallest.

[0124] For example, select the normalized peak-to-peak current i* mode as the optimization objective function, take the normalized transmission power P*mode as the equality condition, and the D1 and D2 constraint relationships between Mode 1 and Mode 2 as the inequality conditions. The mathematical model of this optimization problem is shown in Formula (11):

[0125] (Formula 11);

[0126] Among them, m represents the quantity of inequality constraint conditions, P * mode (D) is the equality constraint condition, and u is the inequality constraint condition;

[0127] Construct the corresponding Lagrangian function L, and the specific expression is shown in Formula (12):

[0128] (Formula 12);

[0129] Among them, λ represents the Lagrange multiplier corresponding to the equality constraint condition of the normalized real-time transmission power, and gn represents the slack variable introduced by the nth inequality constraint.

[0130] During the execution process, the Lagrangian function can be solved through the Karush-Kuhn-Tucker (KKT) conditions; for example, according to the KKT conditions, the optimal solution of the peak-to-peak value of the inductor current is obtained through Formula (13):

[0131] (Formula 13)

[0132] The first shift ratio expression and the second shift ratio expression corresponding to the first power mode and the second power mode are obtained by solving according to Formula 13. Formula (14) is the first shift ratio expression and the second shift ratio expression in the first power mode, and Formula (15) is the first shift ratio expression and the second shift ratio expression in the second power mode:

[0133] (Formula 14);

[0134] (Formula 15).

[0135] It should be noted that the above steps 1201 to 1202 can be executed by the server. After the server finishes the execution, the first shift ratio expression and the second shift ratio expression are obtained. It can also be calculated by the user and / or an external system and then sent to the server after obtaining the first shift ratio expression and the second shift ratio expression. There is no limitation here.

[0136] In this application, the first shift ratio and the second shift ratio are calculated through the constraint conditions of the inequality to obtain the first shift ratio expression and the second shift ratio expression, which improves the calculation accuracy of the first shift ratio and the second shift ratio. At the same time, the calculation of the first shift ratio and the second shift ratio is standardized in the form of an expression, which improves the calculation efficiency of the subsequent shift ratio.

[0137] During the calculation process of the first shift ratio and the second shift ratio, the first shift ratio and the second shift ratio can be calculated according to the first shift ratio expression and the second shift ratio expression included in the shift ratio calculation strategy. In an optional implementation manner provided by this application, as Figure 13 shown, step 203 includes steps 1301 to 1302.

[0138] Step 1301, extract the first shift ratio expression and the second shift ratio expression included in the shift ratio calculation strategy.

[0139] During the implementation process, the server extracts the first shift ratio expression and the second shift ratio expression included in the shift ratio calculation strategy to calculate the first shift ratio and the second shift ratio through the first shift ratio expression and the second shift ratio expression.

[0140] Step 1302, calculate the first shift ratio according to the first shift ratio expression, the per-unit value of the target power, and the voltage transfer ratio, and calculate the second shift ratio according to the second shift ratio expression, the per-unit value of the power, and the voltage transfer ratio.

[0141] During the implementation process, the server substitutes the per-unit value of the target power and the voltage transfer ratio into the first shift ratio expression to calculate the first shift ratio, and substitutes the per-unit value of the target power and the voltage transfer ratio into the second shift ratio expression to obtain the second shift ratio.

[0142] This application calculates the first phase shift ratio and the second phase shift ratio through the first phase shift ratio expression and the second phase shift ratio expression, which improves the calculation efficiency. At the same time, the calculation accuracy is improved through the standardized regular expression.

[0143] In addition, there is also a situation where the heat energy generated in the second power mode is insufficient to melt the ice covering the dual-active full-bridge converter. In response to this, the dual-active full-bridge converter can be modulated through the single-phase-shift modulation strategy to generate higher heat energy for ice melting. An optional implementation provided by this application is as Figure 14 shown, and it also includes step 1401 to step 1402.

[0144] Step 1401, if the per-unit value of the target power is greater than the power upper limit threshold of the second power mode, then generate a target pulse width modulation signal based on the single-phase-shift modulation strategy.

[0145] During the implementation process, if the per-unit value of the target power is greater than the power upper limit threshold of the second power mode, it indicates that the required heat energy is large, and the phase shift ratio corresponding to the second power mode cannot meet the heat energy requirement. Then the server generates a target pulse width modulation signal based on the single-phase-shift modulation strategy.

[0146] Step 1402, control the duty cycle of the switching tubes on the primary-side full-bridge and the duty cycle of the switching tubes on the secondary-side full-bridge according to the target pulse width modulation signal, so as to melt the ice covering through the heat energy generated by the dual-active full-bridge converter.

[0147] During the implementation process, the server controls the duty cycle of the switching tubes on the primary-side full-bridge and the duty cycle of the switching tubes on the secondary-side full-bridge according to the target pulse width modulation signal, so as to control the output power of the dual-active full-bridge converter through the single-phase-shift modulation strategy and generate more heat energy for ice melting.

[0148] An optional implementation provided by this application, in the case of a large per-unit value of the target power, gives priority to ensuring the output of heat energy to ensure the safety of the dual-active full-bridge converter. This application gives priority to ensuring the power transmission efficiency when the ice covering degree of the dual-active full-bridge converter does not affect safety, and gives priority to ensuring safety by increasing heat energy when the ice covering affects safety, which improves the safety of the dual-active full-bridge converter.

[0149] In one of the embodiments, an experimental example of controlling the dual-active full-bridge converter through the pulse width modulation signals generated by the first phase shift ratio and the second phase shift ratio is also provided; for example, the transmission power surface diagram of the DAB converter under the modulation strategy is as Figure 15 shown, the control parameters D1 and D2 jointly determine the size of the transmission power. Compared with the SPS modulation, this modulation strategy has higher modulation flexibility; for another example, the surface diagram of the peak-to-peak value characteristic of the inductor current of the DAB converter is asFigure 16 As shown, the control variables D1, D2 and the voltage transfer ratio k jointly determine the peak-to-peak value of the inductor current of the DAB converter. When k is constant, there are combinations of phase shift ratios D1 and D2 available to reduce the peak-to-peak current, such as Figure 17 As shown, when in the low transmission power range, the optimal solution is derived from the first power mode; while when in the high transmission power range, the optimal solution is derived from the second power mode.

[0150] In one embodiment, referring to Figure 18 , which shows a flowchart of an ice melting method for a dual active full-bridge converter provided by an embodiment of the present application. The ice melting method for the dual active full-bridge converter can be applied to Figure 1 the server shown in Figure 18 As shown, the ice melting method for the dual active full-bridge converter may include the following steps:

[0151] Step 1801, when there is ice covering on the dual active full-bridge converter, obtain the temperature and humidity data of the temperature and humidity sensor. When the temperature and humidity data exceed the ice covering threshold of the dual active full-bridge converter, generate a target power per unit value according to the temperature and humidity data.

[0152] Step 1802, if the target power per unit value is greater than the power upper limit threshold of the first power mode, determine the power mode of the dual active full-bridge converter as the second power mode, and obtain the phase shift ratio calculation strategy corresponding to the second power mode.

[0153] Step 1803, extract the first phase shift ratio expression and the second phase shift ratio expression included in the phase shift ratio calculation strategy.

[0154] Step 1804, calculate the first phase shift ratio according to the first phase shift ratio expression, the target power per unit value and the voltage transfer ratio, and calculate the second phase shift ratio according to the second phase shift ratio expression, the power per unit value and the voltage transfer ratio.

[0155] Step 1805, generate a pulse width modulation signal based on the first phase shift ratio and the second phase shift ratio, and control the duty cycle of the switching tubes on the primary side full-bridge and the duty cycle of the switching tubes on the secondary side full-bridge according to the pulse width modulation signal, so as to melt the ice covering through the heat energy generated by the dual active full-bridge converter.

[0156] It should be noted that any one or any combination of steps 1801 to 1805 can be combined with any one or any combination of steps 201 to 204 provided in the above embodiments according to the needs of implementation and deployment to form a new implementation manner; and any one or any combination of technical features in the technical solution formed by steps 1801 to 1805 can also be combined with any one or more technical features in the technical solution formed by steps 201 to 204 provided above according to the actual deployment requirements to form a new implementation manner, or select the technical features in one or more optional implementation manners provided in the above one or more embodiments to form a new implementation manner. Details are not described herein one by one.

[0157] It should be understood that although the steps in the flowcharts involved in the above embodiments are shown in sequence according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless specifically stated herein, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be executed alternately or in turn with at least a part of other steps or steps or stages in other steps. It can be understood that the steps in different embodiments can be freely combined as needed, and all non-contradictory solutions formed by the combination belong to the scope of protection of the present application.

[0158] Based on the same inventive concept, an ice melting device for a dual active full-bridge converter for implementing the ice melting method of the dual active full-bridge converter involved above is also provided in an embodiment of the present application. The implementation solution provided by this device to solve the problem is similar to the implementation solution described in the above method. Therefore, the specific limitations in one or more embodiments of the ice melting device for a dual active full-bridge converter provided below can refer to the limitations on the ice melting method of the dual active full-bridge converter in the above text, and details are not described herein again.

[0159] In an exemplary embodiment, as Figure 19 shown, an ice melting device for a dual active full-bridge converter is provided, including: a target power per unit value acquisition module 1901, a phase shift ratio calculation strategy acquisition module 1902, a phase shift ratio calculation module 1903, and a converter control module 1904, where:

[0160] The target power per unit value acquisition module 1901 is configured to acquire the target power per unit value of the dual active full-bridge converter when the dual active full-bridge converter is covered with ice;

[0161] The phase shift ratio calculation strategy acquisition module 1902 is configured to determine the current power mode of the dual-active-bridge converter according to the per-unit value of the target power, and acquire the phase shift ratio calculation strategy corresponding to the power mode;

[0162] The phase shift ratio calculation module 1903 is configured to calculate a first phase shift ratio of the primary-side full bridge and a second phase shift ratio of the secondary-side full bridge of the dual-active-bridge converter according to the phase shift ratio calculation strategy, the per-unit value of the target power, and the voltage transfer ratio of the dual-active-bridge converter;

[0163] The converter control module 1904 is configured to generate a pulse width modulation signal based on the first phase shift ratio and the second phase shift ratio, and control the duty cycle of the switching tubes of the primary-side full bridge and the duty cycle of the switching tubes of the secondary-side full bridge according to the pulse width modulation signal, so as to melt the ice covering through the heat energy generated by the dual-active-bridge converter.

[0164] In one embodiment, the phase shift ratio calculation module 1903 includes a first phase shift ratio expression extraction unit and a phase shift ratio calculation unit, where: the first phase shift ratio expression extraction unit is configured to extract a first phase shift ratio expression and a second phase shift ratio expression included in the phase shift ratio calculation strategy; the phase shift ratio calculation unit is configured to calculate the first phase shift ratio according to the first phase shift ratio expression, the per-unit value of the target power, and the voltage transfer ratio, and calculate the second phase shift ratio according to the second phase shift ratio expression, the per-unit value of the power, and the voltage transfer ratio.

[0165] In one embodiment, the device further includes an actual parameter acquisition module and a phase shift ratio expression calculation module, where: the actual parameter acquisition module is configured to acquire the per-unit value of the actual power and the per-unit value of the actual inductor current of the current power mode of the dual-active-bridge converter; the phase shift ratio expression calculation module is configured to solve for the phase shift ratio according to the preset constraint conditions and the Lagrangian function to obtain the first phase shift ratio expression and the second phase shift ratio expression, and the constraint conditions include that the per-unit value of the actual power is equal to the per-unit value of the target power, and the per-unit value of the actual inductor current is the minimum.

[0166] In one embodiment, the actual parameter acquisition module includes: an actual current acquisition unit, an actual parameter calculation unit, and a per-unit value calculation unit, where: the actual current acquisition unit is configured to acquire the actual inductor current corresponding to multiple level conversion moments within one modulation period of the dual-active-bridge converter; the actual parameter calculation unit is configured to obtain the peak value of the actual inductor current and the actual transmitted power in the current power mode of the dual-active-bridge converter according to each actual inductor current, the first unknown parameter corresponding to the first phase shift ratio, and the second unknown parameter corresponding to the second phase shift ratio; the per-unit value calculation unit is configured to obtain the actual power per-unit value based on the actual transmitted power and the reference power, and obtain the actual inductor current per-unit value based on the peak value and the reference current, where the reference power is the upper limit transmitted power of the dual-active-bridge converter under the single-phase-shift modulation strategy, and the reference current is the inductor current corresponding to the upper limit transmitted power.

[0167] In one embodiment, the phase shift ratio calculation strategy acquisition module 1902 includes: a first power mode determination module and a second power mode determination module, where: the first power mode determination module is configured to determine that the power mode of the dual-active-bridge converter is the first power mode and obtain the phase shift ratio calculation strategy corresponding to the first power mode if the target power per-unit value is less than the power upper limit threshold of the first power mode; the second power mode determination module is configured to determine that the power mode of the dual-active-bridge converter is the second power mode and obtain the phase shift ratio calculation strategy corresponding to the second power mode if the target power per-unit value is greater than the power upper limit threshold of the first power mode.

[0168] In one embodiment, the device further includes: a single-phase-shift modulation module and a switch tube control module, where: the single-phase-shift modulation module is configured to generate a target pulse width modulation signal based on the single-phase-shift modulation strategy if the target power per-unit value is greater than the power upper limit threshold of the second power mode; the switch tube control module is configured to control the duty cycle of the switch tubes on the primary-side full bridge and the duty cycle of the switch tubes on the secondary-side full bridge according to the target pulse width modulation signal, so as to melt the ice coating through the heat energy generated by the dual-active-bridge converter.

[0169] In one embodiment, the target power per-unit value acquisition module 1901 further includes: a first target power per-unit value acquisition unit and a second target power per-unit value acquisition unit, where: the first target power per-unit value acquisition unit is configured to acquire the temperature and humidity data of the temperature and humidity sensor, and generate a target power per-unit value according to the temperature and humidity data if the temperature and humidity data exceeds the ice coating threshold of the dual-active-bridge converter; the second target power per-unit value acquisition unit is configured to acquire the preset output voltage input externally and the actual output voltage of the dual-active-bridge converter, calculate the difference between the actual output voltage and the preset output voltage, and generate a target power per-unit value based on the difference through a proportional-integral regulator.

[0170] Each module in the ice melting device of the above-mentioned dual-active full-bridge converter can be implemented in whole or in part by software, hardware, and their combination. Each of the above modules can be embedded in or independent of a processor in a computer device in the form of hardware, or stored in a memory in the computer device in the form of software, so that the processor can call and execute the operations corresponding to each of the above modules.

[0171] In an exemplary embodiment, a computer device is provided. The computer device can be a server, and its internal structure diagram can be as Figure 20 shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O), and a communication interface. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data of the dual-active full-bridge converter. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, it realizes a method for melting ice of a dual-active full-bridge converter.

[0172] Those skilled in the art can understand that Figure 20 the structure shown in

[0173] is only a block diagram of a part of the structure related to the solution of this application, and does not constitute a limitation on the computer device to which the solution of this application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0174] When there is icing on the dual-active full-bridge converter, obtain the per-unit value of the target power of the dual-active full-bridge converter;

[0175] Determine the current power mode of the dual-active full-bridge converter according to the per-unit value of the target power, and obtain the phase-shift ratio calculation strategy corresponding to the power mode;

[0176] Calculate the first phase-shift ratio of the primary-side full-bridge and the second phase-shift ratio of the secondary-side full-bridge of the dual-active full-bridge converter according to the phase-shift ratio calculation strategy, the per-unit value of the target power, and the voltage transfer ratio of the dual-active full-bridge converter;

[0177] Generate a pulse width modulation signal based on a first phase shift ratio and a second phase shift ratio, and control the duty cycle of the switching tubes of the primary full-bridge and the duty cycle of the switching tubes of the secondary full-bridge according to the pulse width modulation signal, so as to melt the ice covering through the heat energy generated by the dual-active full-bridge converter.

[0178] In one embodiment, when the processor executes the computer program, the following steps are specifically implemented:

[0179] Extract the first phase shift ratio expression and the second phase shift ratio expression included in the phase shift ratio calculation strategy;

[0180] Calculate the first phase shift ratio according to the first phase shift ratio expression, the per-unit value of the target power, and the voltage transfer ratio, and calculate the second phase shift ratio according to the second phase shift ratio expression, the per-unit value of the power, and the voltage transfer ratio.

[0181] In one embodiment, when the processor executes the computer program, the following steps are further implemented:

[0182] Obtain the actual per-unit value of the power and the actual per-unit value of the inductor current of the current power mode of the dual-active full-bridge converter;

[0183] Solve the phase shift ratio according to the preset constraint conditions and the Lagrangian function to obtain the first phase shift ratio expression and the second phase shift ratio expression. The constraint conditions include that the actual per-unit value of the power is equal to the per-unit value of the target power, and the actual per-unit value of the inductor current is the smallest.

[0184] In one embodiment, when the processor executes the computer program, the following steps are specifically implemented:

[0185] Obtain the actual inductor current corresponding to multiple level conversion moments within a modulation period of the dual-active full-bridge converter;

[0186] According to each actual inductor current, the first unknown parameter corresponding to the first phase shift ratio, and the second unknown parameter corresponding to the second phase shift ratio, obtain the peak value of the actual inductor current and the actual transmitted power in the current power mode of the dual-active full-bridge converter;

[0187] Obtain the actual per-unit value of the power based on the actual transmitted power and the reference power, and obtain the actual per-unit value of the inductor current based on the peak value and the reference current. The reference power is the upper limit transmitted power of the dual-active full-bridge converter under the single-phase shift modulation strategy, and the reference current is the inductor current corresponding to the upper limit transmitted power.

[0188] In one embodiment, when the processor executes the computer program, the following steps are specifically implemented:

[0189] If the per-unit value of the target power is greater than the power upper limit threshold of the first power mode, determine the power mode of the dual-active-bridge converter as the second power mode, and obtain the phase-shift ratio calculation strategy corresponding to the second power mode;

[0190] If the per-unit value of the target power is less than the power upper limit threshold of the first power mode, determine the power mode of the dual-active-bridge converter as the first power mode, and obtain the phase-shift ratio calculation strategy corresponding to the first power mode.

[0191] In one embodiment, when the processor executes the computer program, the following steps are further implemented:

[0192] If the per-unit value of the target power is greater than the power upper limit threshold of the second power mode, generate a target pulse width modulation signal based on the single-phase-shift modulation strategy;

[0193] Control the duty cycle of the switching tubes on the primary-side full bridge and the duty cycle of the switching tubes on the secondary-side full bridge according to the target pulse width modulation signal, so as to melt the ice coating by the heat energy generated by the dual-active-bridge converter.

[0194] In one embodiment, when the processor executes the computer program, the following steps are specifically implemented:

[0195] Obtain the temperature and humidity data of the temperature and humidity sensor. When the temperature and humidity data exceed the ice coating threshold of the dual-active-bridge converter, generate the per-unit value of the target power according to the temperature and humidity data;

[0196] Alternatively, obtain the preset output voltage input externally and the actual output voltage of the dual-active-bridge converter, calculate the difference between the actual output voltage and the preset output voltage, and generate the per-unit value of the target power based on the difference through a proportional-integral regulator.

[0197] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0198] In one embodiment, a computer program product is provided, including a computer program. When the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0199] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in the present application are all information and data authorized by the user or fully authorized by all parties, and the collection, use, and processing of the relevant data need to comply with the relevant regulations.

[0200] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, a database, or other media used in the embodiments provided in the present application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The databases involved in the embodiments provided in the present application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the embodiments provided in the present application can be general-purpose processors, central processors, graphics processors, digital signal processors, programmable logic devices, data processing logics based on quantum computing, artificial intelligence (AI) processors, etc., without limitation.

[0201] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, 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, it should be considered to be within the scope recorded in the present application.

[0202] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A method for melting ice of a dual-active full-bridge converter, characterized in that, The method includes: When icing exists in the dual-active full-bridge converter, obtaining the per-unit value of the target power of the dual-active full-bridge converter; Determining the current power mode of the dual-active full-bridge converter according to the per-unit value of the target power, and obtaining the phase-shift ratio calculation strategy corresponding to the power mode; Calculating a first phase-shift ratio of the primary-side full-bridge and a second phase-shift ratio of the secondary-side full-bridge of the dual-active full-bridge converter according to the phase-shift ratio calculation strategy, the per-unit value of the target power, and the voltage transfer ratio of the dual-active full-bridge converter; Generating a pulse-width modulation signal based on the first phase-shift ratio and the second phase-shift ratio, and controlling the duty cycle of the switching tubes of the primary-side full-bridge and the duty cycle of the switching tubes of the secondary-side full-bridge according to the pulse-width modulation signal, so as to melt the icing through the heat energy generated by the dual-active full-bridge converter.

2. The method according to claim 1, wherein The calculating the first phase-shift ratio of the primary-side full-bridge and the second phase-shift ratio of the secondary-side full-bridge of the dual-active full-bridge converter according to the phase-shift ratio calculation strategy, the per-unit value of the target power, and the voltage transfer ratio of the dual-active full-bridge converter includes: Extracting a first phase-shift ratio expression and a second phase-shift ratio expression included in the phase-shift ratio calculation strategy; Calculating the first phase-shift ratio according to the first phase-shift ratio expression, the per-unit value of the target power, and the voltage transfer ratio, and calculating the second phase-shift ratio according to the second phase-shift ratio expression, the per-unit value of the power, and the voltage transfer ratio.

3. The method according to claim 2, wherein The generation process of the first phase-shift ratio expression and the second phase-shift ratio expression includes: Obtaining the per-unit value of the actual power and the per-unit value of the actual inductor current of the current power mode of the dual-active full-bridge converter; Solving the phase-shift ratio according to the preset constraint conditions and the Lagrangian function to obtain the first phase-shift ratio expression and the second phase-shift ratio expression, where the constraint conditions include that the per-unit value of the actual power is equal to the per-unit value of the target power, and the per-unit value of the actual inductor current is the smallest.

4. The method according to claim 3, wherein The obtaining the per-unit value of the actual power and the per-unit value of the actual inductor current of the current power mode of the dual-active full-bridge converter includes: Obtaining the actual inductor current corresponding to multiple level conversion moments within a modulation period of the dual-active full-bridge converter; Obtaining the peak value of the actual inductor current and the actual transmitted power in the current power mode of the dual-active full-bridge converter according to each actual inductor current, the first unknown parameter corresponding to the first phase-shift ratio, and the second unknown parameter corresponding to the second phase-shift ratio; Obtaining the per-unit value of the actual power based on the actual transmitted power and the reference power, and obtaining the per-unit value of the actual inductor current based on the peak value and the reference current, where the reference power is the upper limit transmitted power of the dual-active full-bridge converter under the single-phase-shift modulation strategy, and the reference current is the inductor current corresponding to the upper limit transmitted power.

5. The method according to claim 1, wherein The determining the current power mode of the dual-active full-bridge converter according to the per-unit value of the target power, and obtaining the phase-shift ratio calculation strategy corresponding to the power mode includes: If the per-unit value of the target power is greater than the power upper limit threshold of the first power mode, determine that the power mode of the dual-active-bridge converter is the second power mode, and obtain the phase-shift ratio calculation strategy corresponding to the second power mode; If the per-unit value of the target power is less than the power upper limit threshold of the first power mode, determine that the power mode of the dual-active-bridge converter is the first power mode, and obtain the phase-shift ratio calculation strategy corresponding to the first power mode.

6. The method according to claim 5, wherein The method further includes: If the per-unit value of the target power is greater than the power upper limit threshold of the second power mode, generate a target pulse width modulation signal based on the single-phase phase-shift modulation strategy; Control the duty cycle of the switching tubes of the primary-side full bridge and the duty cycle of the switching tubes of the secondary-side full bridge according to the target pulse width modulation signal, so as to melt the ice coating by the heat energy generated by the dual-active-bridge converter.

7. The method according to claim 1, wherein The obtaining of the per-unit value of the target power of the dual-active-bridge converter includes: Obtain the temperature and humidity data of the temperature and humidity sensor, and generate the per-unit value of the target power according to the temperature and humidity data when the temperature and humidity data exceed the ice coating threshold of the dual-active-bridge converter; Alternatively, obtain the preset output voltage input externally and the actual output voltage of the dual-active-bridge converter, calculate the difference between the actual output voltage and the preset output voltage, and generate the per-unit value of the target power based on the difference by a proportional-integral regulator.

8. An ice melting device for a dual-active full-bridge converter, characterized in that, The device includes: A per-unit value of target power obtaining module, configured to obtain the per-unit value of the target power of the dual-active-bridge converter when there is ice coating on the dual-active-bridge converter; A phase-shift ratio calculation strategy obtaining module, configured to determine the current power mode of the dual-active-bridge converter according to the per-unit value of the target power, and obtain the phase-shift ratio calculation strategy corresponding to the power mode; A phase-shift ratio calculation module, configured to calculate a first phase-shift ratio of the primary-side full bridge and a second phase-shift ratio of the secondary-side full bridge of the dual-active-bridge converter according to the phase-shift ratio calculation strategy, the per-unit value of the target power, and the voltage transfer ratio of the dual-active-bridge converter; A converter control module, configured to generate a pulse width modulation signal based on the first phase-shift ratio and the second phase-shift ratio, and control the duty cycle of the switching tubes of the primary-side full bridge and the duty cycle of the switching tubes of the secondary-side full bridge according to the pulse width modulation signal, so as to melt the ice coating by the heat energy generated by the dual-active-bridge converter.

9. A computer device, comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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