CN117240094A

CN117240094A - Control method, battery system, device, equipment and medium for DC/DC converter

Info

Publication number: CN117240094A
Application number: CN202311482989.XA
Authority: CN
Inventors: 罗宇; 林贵应; 陈金山; 陈鹏辉; 潘先喜
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2023-11-09
Filing date: 2023-11-09
Publication date: 2023-12-15
Anticipated expiration: 2043-11-09
Also published as: CN117240094B

Abstract

The application discloses a control method, a battery system, a device, equipment and a medium of a DC/DC converter. The control method of the DC/DC converter comprises the following steps: obtaining the output voltage of the DC/DC converter; if the absolute value of the output voltage is larger than the first voltage threshold value, the absolute value of the output voltage of the DC/DC converter is reduced; and controlling the DC/DC converter to switch to the bypass state when the absolute value of the output voltage of the DC/DC converter is reduced to be less than or equal to a second voltage threshold value, wherein the second voltage threshold value is less than or equal to the first voltage threshold value. According to the embodiment of the application, the reliability of switching the DC/DC converter from the working state to the bypass state is improved.

Description

Control method, battery system, device, equipment and medium for DC/DC converter

Technical Field

The present application relates to the field of DC/DC converter control technologies, and in particular, to a method, a battery system, a device, equipment, and a medium for controlling a DC/DC converter.

Background

With the continuous development of modern power electronic technology and new energy industry, energy storage technology using a battery cabinet as a core unit is widely focused. Currently, the energy capacity of an energy storage power station can be improved in a mode of parallel connection of multi-branch battery clusters. However, with the increase of the number of the branches of the battery clusters, the current imbalance phenomenon of the energy storage power station caused by the difference of the branches of the battery clusters often occurs, so that the service life of the energy storage power station is shortened. Moreover, inter-cluster circulation due to branch differences also poses a safety risk. A common solution to this risk is to use a DC/DC (Direct Current/Direct Current) converter to regulate the voltage of each battery cluster, so as to achieve inter-cluster Current sharing.

However, in the case where the DC/DC converter is switched from the operation state to the bypass state, the DC/DC converter is liable to suffer from an unreliable problem.

Disclosure of Invention

The application provides a control method, a battery system, a device, equipment and a medium of a DC/DC converter, which are beneficial to improving the reliability of switching the DC/DC converter from a working state to a bypass state.

In a first aspect, the present application provides a control method of a DC/DC converter, including: obtaining the output voltage of the DC/DC converter; if the absolute value of the output voltage is larger than the first voltage threshold value, the absolute value of the output voltage of the DC/DC converter is reduced; and controlling the DC/DC converter to switch to the bypass state when the absolute value of the output voltage of the DC/DC converter is reduced to be less than or equal to a second voltage threshold value, wherein the second voltage threshold value is less than or equal to the first voltage threshold value.

In a possible implementation manner of the first aspect, the method further includes: and if the absolute value of the output voltage is smaller than or equal to the first voltage threshold value, controlling the DC/DC converter to switch to the bypass state.

In a possible implementation manner of the first aspect, the DC/DC converter includes a voltage regulation module, where the voltage regulation module includes three branches connected in parallel, each branch includes an upper switching tube and a lower switching tube connected in series, and the bypass state includes a primary bypass state and a secondary bypass state;

Controlling the DC/DC converter to switch to a bypass state, comprising:

the DC/DC converter is controlled to be switched to a first-stage bypass state firstly, and then, the first-stage bypass state is switched to a second-stage bypass state, wherein in the first-stage bypass state, an upper switching tube in each branch is conducted, a lower switching tube in each branch is turned off, and in the second-stage bypass state, the upper switching tube and the lower switching tube in each branch are conducted.

In a possible implementation manner of the first aspect, the DC/DC converter includes a voltage regulation module, the voltage regulation module including a switching tube, reducing an absolute value of an output voltage of the DC/DC converter, including:

the duty ratio of the control signal of the switching tube is reduced to reduce the absolute value of the output voltage of the DC/DC converter, wherein the smaller the duty ratio of the control signal of the switching tube is, the smaller the absolute value of the output voltage of the DC/DC converter is.

Based on the same inventive concept, in a second aspect, an embodiment of the present application further provides a battery system, the battery system including a controller, a plurality of parallel battery clusters, and a DC/DC converter connected to the battery clusters, wherein the controller is connected to the DC/DC converter;

the controller is used for acquiring the output voltage of the DC/DC converter in the working state, if the absolute value of the output voltage is larger than a first voltage threshold value, controlling the absolute value of the output voltage of the DC/DC converter to be reduced, and under the condition that the absolute value of the output voltage of the DC/DC converter is reduced to be smaller than or equal to a second voltage threshold value, controlling the DC/DC converter to be switched to a bypass state; wherein the second voltage threshold is less than or equal to the first voltage threshold.

In a possible implementation manner of the second aspect, the controller is further configured to:

and if the absolute value of the output voltage is smaller than or equal to the first voltage threshold value, controlling the DC/DC converter to switch to the bypass state.

In a possible implementation manner of the second aspect, the DC/DC converter includes a voltage regulation module, where the voltage regulation module includes three branches connected in parallel, each branch includes an upper switching tube and a lower switching tube connected in series, and the bypass state includes a primary bypass state and a secondary bypass state;

a controller for controlling the switching of the DC/DC converter to a bypass state, comprising:

and the controller is used for controlling the DC/DC converter to be firstly switched to a first-stage bypass state and then switched to a second-stage bypass state from the first-stage bypass state, wherein in the first-stage bypass state, an upper switching tube in each branch is conducted, a lower switching tube in each branch is turned off, and in the second-stage bypass state, both the upper switching tube and the lower switching tube in each branch are conducted.

In a possible implementation manner of the second aspect, the DC/DC converter includes a voltage regulation module, the voltage regulation module includes a switching tube, and the controller is configured to reduce an absolute value of an output voltage of the DC/DC converter, and includes:

the controller is used for reducing the duty ratio of the control signal of the switching tube so as to reduce the absolute value of the output voltage of the DC/DC converter, wherein the smaller the duty ratio of the control signal of the switching tube is, the smaller the absolute value of the output voltage of the DC/DC converter is.

Based on the same inventive concept, in a third aspect, an embodiment of the present application further provides a control device of a DC/DC converter, including:

the voltage acquisition module is used for acquiring the output voltage of the DC/DC converter;

the step-down control module is used for controlling the absolute value of the output voltage of the DC/DC converter to be reduced if the absolute value of the output voltage is larger than a first voltage threshold value;

and the switching control module is used for controlling the DC/DC converter to switch to the bypass state under the condition that the absolute value of the output voltage of the DC/DC converter is reduced to be smaller than or equal to a second voltage threshold value, wherein the second voltage threshold value is smaller than or equal to the first voltage threshold value.

Based on the same inventive concept, in a fourth aspect, an embodiment of the present application further provides an electronic device, including: a processor and a memory storing computer program instructions;

the processor, when executing the computer program instructions, implements a method for controlling a DC/DC converter according to any one of the embodiments of the first aspect.

Based on the same inventive concept, in a fifth aspect, an embodiment of the present application further provides a computer readable storage medium, which is characterized in that the computer readable storage medium stores computer program instructions, which when executed by a processor, implement the control method of the DC/DC converter according to any one of the embodiments of the first aspect.

According to the embodiment of the application, if the absolute value of the output voltage of the DC/DC converter is larger than the first voltage threshold, the absolute value of the output voltage of the DC/DC converter is reduced to the second voltage threshold, and then the DC/DC converter is controlled to be switched from the working state to the bypass state. Therefore, the DC/DC converter can be prevented from being directly switched to the bypass state under the condition that the absolute value of the output voltage is large, the possibility of overcurrent of the DC/DC converter can be reduced, and the reliability of the DC/DC converter is improved.

The foregoing description is only an overview of the present application, and is intended to be implemented in accordance with the teachings of the present application in order that the same may be more clearly understood and to make the same and other objects, features and advantages of the present application more readily apparent.

Drawings

Features, advantages, and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

Fig. 1 is a schematic flow chart of a control method of a DC/DC converter according to an embodiment of the application;

fig. 2 is a schematic circuit diagram of a battery system according to an embodiment of the application;

fig. 3 is a schematic circuit diagram of a DC/DC converter according to an embodiment of the application;

Fig. 4 is a schematic flow chart of a control method of a DC/DC converter according to another embodiment of the application;

FIG. 5 is a schematic diagram of a current loop of a DC/DC converter according to an embodiment of the application;

FIG. 6 is a schematic diagram of another current loop of a DC/DC converter according to an embodiment of the application;

fig. 7 is a flowchart of a control method of a DC/DC converter according to another embodiment of the present application;

fig. 8 is a schematic structural diagram of a control device of a DC/DC converter according to an embodiment of the present application;

fig. 9 is a schematic structural diagram of an electronic device according to an embodiment of the application.

In the drawings, the drawings are not necessarily to scale.

In the accompanying drawings:

100. a battery system;

10. a DC/DC converter;

11. a voltage regulation module; 12. an LLC resonant module; 121. a transformer;

20. a controller; 30. a battery cluster; 31. a first bus; 32. and a second bus bar.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having" and any variations thereof in the description of the application and the claims and the description of the drawings above are intended to cover a non-exclusive inclusion. The terms first, second and the like in the description and in the claims or in the above-described figures, are used for distinguishing between different objects and not necessarily for describing a particular sequential or chronological order.

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "attached" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

Embodiments of the present application provide a control method, a battery system, an apparatus, a device, and a medium for a DC/DC converter, and embodiments of the present application will be described in detail with reference to the accompanying drawings.

As shown in fig. 1, a control method of a DC/DC converter according to an embodiment of the present application includes S10 to S30.

S10, obtaining the output voltage of the DC/DC converter.

S20, if the absolute value of the output voltage is larger than the first voltage threshold, the absolute value of the output voltage of the DC/DC converter is reduced.

And S30, controlling the DC/DC converter to switch to a bypass state under the condition that the absolute value of the output voltage of the DC/DC converter is reduced to be smaller than or equal to a second voltage threshold value, wherein the second voltage threshold value is smaller than or equal to the first voltage threshold value.

The specific implementation of each of the above steps will be described in detail below.

The DC/DC converter can adjust the voltage of each battery cluster to realize the current sharing among clusters. In the case where a DC/DC converter is required to equalize the voltages of the respective battery clusters, the DC/DC converter may be controlled to be in an operating state. The DC/DC converter may be switched from the operating state to the bypass state without the need for the DC/DC converter to be equalized. However, when the DC/DC converter is in an operating state and the absolute value of the output voltage is large, if the DC/DC converter is suddenly switched from the operating state to the bypass state, the DC/DC converter is liable to generate an overcurrent phenomenon, so that the DC/DC converter is liable to generate an unreliable problem, thereby affecting the operating stability of the battery cluster.

According to the control method of the DC/DC converter provided by the embodiment of the application, if the absolute value of the output voltage of the DC/DC converter is larger than the first voltage threshold value, the absolute value of the output voltage of the DC/DC converter is firstly reduced to the second voltage threshold value, and then the DC/DC converter is controlled to be switched from the working state to the bypass state. Therefore, the DC/DC converter can be prevented from being directly switched to the bypass state under the condition that the absolute value of the output voltage is large, the possibility of overcurrent of the DC/DC converter can be reduced, and the reliability of the DC/DC converter is improved.

Illustratively, the DC/DC converter in the embodiments of the present application may be applied to a battery system. Referring to fig. 2, the battery system 100 may include a plurality of battery clusters 30 connected in parallel, and the DC/DC converter 10 is connected to the battery clusters 30. Each battery cluster 30 is made up of a plurality of batteries connected in series. When the energy storage system is charged and discharged, a voltage difference may occur between the plurality of battery clusters 30 to cause a current imbalance phenomenon, and damage is caused to the battery, so as shown in fig. 2, the DC/DC converter 10 is connected to the battery clusters 30, and the voltage difference between the battery clusters 30 is reduced by the DC/DC converter 10.

The DC/DC converter can compensate the voltage of the battery cluster under the working state.

For example, the difference between the voltages of the battery clusters may be determined according to the voltages of the battery clusters, and the compensation voltages of the DC/DC converters corresponding to the battery clusters may be calculated, and the DC/DC converters may be controlled to output the corresponding compensation voltages. For example, one battery cluster and the DC/DC converter connected with the battery cluster are called one battery unit, the output total voltage of each battery unit is the sum of the battery cluster voltage and the compensation voltage output by the DC/DC converter, when the battery cluster voltages are different, the battery cluster voltage can be compensated by adjusting the value of the compensation voltage, that is, the output total voltage of each battery unit can be kept balanced.

The voltage output by the DC/DC converter may be a positive voltage or a negative voltage. For example, in the case where a certain battery cluster voltage is less than a target voltage, the DC/DC converter to which the battery cluster is connected may be used to output a positive voltage; in the case that the voltage of a certain battery cluster is greater than the target voltage, the DC/DC converter connected with the battery cluster can be used for outputting negative voltage, wherein the target voltage is the voltage required to be reached by a plurality of battery clusters. In other words, the DC/DC converter may be used to increase the total output voltage of the battery cells, and may also be used to decrease the total output voltage of the battery cells.

After receiving a request that the DC/DC converter needs to switch from the operation state to the bypass state, the output voltage of the DC/DC converter is compared with the first voltage threshold. In the case where the DC/DC converter needs to be maintained in an operating state, it may not be necessary to compare the output voltage of the DC/DC converter with the first voltage threshold value, nor to switch the state of the DC/DC converter.

In some embodiments, the DC/DC converter may include a voltage feedback module that may be used to feedback the output voltage of the DC/DC converter. In S10, the output voltage of the voltage feedback module may be obtained by the voltage feedback module. In S10, an output voltage of the DC/DC converter in the operating state is obtained.

In some embodiments, the specific values of the first voltage threshold in S20 and the second voltage threshold in S30 may be determined through experimental tests, for example, when the DC/DC converter is switched from the operating state to the bypass state, if the absolute value of the output voltage of the DC/DC converter is greater than the first voltage threshold, the DC/DC converter is triggered to generate an overcurrent problem, and if the absolute value of the output voltage of the DC/DC converter is less than or equal to the second voltage threshold, the DC/DC converter is not triggered to generate an overcurrent problem.

Of course, the specific values of the first voltage threshold in S20 and the second voltage threshold in S30 may also be determined according to other manners, which is not limited by the present application.

As one example, the first voltage threshold is 8V and the second voltage threshold is 5V.

It is understood that there may be a spike voltage or a spike voltage in the output voltage of the DC/DC converter, and in the case that the second voltage threshold is smaller than the first voltage threshold, it is more beneficial to ensure the reliability of switching the DC/DC converter from the operating state to the bypass state.

In S20, if the output voltage of the DC/DC converter is a positive voltage, the absolute value of the output voltage of the DC/DC converter is reduced, that is,: reducing the output voltage of the DC/DC converter; if the output voltage of the DC/DC converter is a negative voltage, the absolute value of the output voltage of the DC/DC converter is reduced, namely: the output voltage of the DC/DC converter is increased.

In some embodiments, as shown in fig. 3, the DC/DC converter 10 may include a voltage regulation module 11, the voltage regulation module 11 including a switching tube. Reducing the absolute value of the output voltage of the DC/DC converter in S20 may include: the duty ratio of the control signal of the switching tube is reduced to reduce the absolute value of the output voltage of the DC/DC converter, wherein the smaller the duty ratio of the control signal of the switching tube is, the smaller the absolute value of the output voltage of the DC/DC converter is.

As one example, as shown in fig. 3, the voltage regulation module 11 may include a first branch, a second branch, and a third branch, which are connected in parallel. Each branch may include an upper switching tube and a lower switching tube connected in series. For example, the upper switching tube and the lower switching tube of the first branch are respectively labeled as an upper switching tube Q1 and a lower switching tube Q2; the upper switching tube and the lower switching tube of the second branch are respectively marked as an upper switching tube Q3 and a lower switching tube Q4; the upper switching tube and the lower switching tube of the third branch are respectively marked as an upper switching tube Q5 and a lower switching tube Q6. The voltage regulation module 11 may further include a first inductance L1, a second inductance L2, and a first capacitance C1.

The switching transistors Q1, Q2, Q3, Q4 may include Metal-Oxide-semiconductor field effect transistors (MOSFETs) and the switching transistors Q1, Q2, Q3, Q4 include body diodes D1, D2, D3, D4, respectively.

The voltage regulation module 11 may be a bi-directional buck-boost voltage regulation module. When the lower switching tube Q2 is turned off, the upper switching tube Q1, the diode D2 and the first inductor L1 form a first buck type voltage reducing circuit; when the lower switching tube Q4 is turned off, the upper switching tube Q3, the diode D4 and the second inductor L2 form a second buck type voltage-reducing circuit. The first buck voltage-reducing circuit and the second buck voltage-reducing circuit are connected in parallel to realize power supply to the later-stage load. Conversely, when the upper switching tube Q1 is turned off, the lower switching tube Q2, the diode D1 and the first inductor L1 form a first boost type boost circuit; when the upper switching tube Q3 is turned off, the lower switching tube Q4, the diode D3 and the second inductor L2 form a second boost circuit. The first boost circuit and the second boost circuit are connected in parallel to realize energy supplement to the front-end power supply.

Illustratively, reducing the duty cycle of the control signal of the switching tube to reduce the absolute value of the output voltage of the DC/DC converter may include:

the lower switching tube Q2 and the lower switching tube Q4 are controlled to be turned off, and the duty ratio of control signals of the upper switching tube Q1 and the upper switching tube Q3 is reduced, so that the absolute value of the output voltage of the DC/DC converter is reduced.

The control signals of the upper switching transistor Q1 and the upper switching transistor Q3 may be PWM (Pulse Width Modulation ) signals.

Illustratively, a first end of the first capacitor C1 is connected to the first node N1, a second end of the first capacitor C1 is connected to the second node N2, the first node N1 is connected to the third node N3 in fig. 2, and the second node N2 is connected to the first bus bar 31 in fig. 2. The first capacitor C1 may be used as a low-voltage side capacitor, and the first capacitor C1 may maintain stability of the output voltage of the DC/DC converter when the DC/DC converter is operated.

The output voltage of the DC/DC converter may refer to the voltage output by the first capacitor C1. Herein, the first capacitor C1 is a low-voltage side capacitor, and the output voltage of the DC/DC converter refers to the low-voltage side output voltage of the DC/DC converter.

The upper switching tube Q5 and the lower switching tube Q6 can be used to control the polarity of the output voltage of the DC/DC converter 10. That is, the upper switching transistor Q5 and the lower switching transistor Q6 are directional transistors in the DC/DC converter 10.

For example, when the upper switching tube Q5 is turned off and the lower switching tube Q6 is turned on, the voltage difference across the first capacitor C1 is of the first polarity, and the DC/DC converter outputs the voltage of the first polarity; under the condition that the upper switch tube Q5 is turned on and the lower switch tube Q6 is turned off, the voltage difference between two ends of the first capacitor C1 is of a second polarity, and the DC/DC converter outputs voltage of the second polarity. Here, the voltage difference across the first capacitor C1 may refer to a difference between the voltage at the second terminal and the voltage at the first terminal thereof, i.e., a difference between the voltage at the second node N2 and the voltage at the first node N1. The first polarity is illustratively positive and the second polarity is negative.

It should be noted that, in fig. 3, the plurality of wires have a solid black dot at the intersection, which indicates that the plurality of wires are connected at the intersection; the fact that the plurality of wires have no black solid points at the intersections indicates that the plurality of wires have no connection relationship at the intersections.

Illustratively, as shown in FIG. 3, the DC/DC converter 10 may further include an LLC resonant module 12, which may include a third inductance L3, a third inductance L4, a second capacitance C2, a transformer 121, and switching tubes Q7-Q14. The LLC resonant module 12 can constitute a bi-directional isolated power supply module.

For example, as shown in fig. 3, a third capacitor C3 may be connected between the positive electrode and the negative electrode of the battery, and the third capacitor C3 may be used to maintain the high voltage output stability of the battery.

A fourth capacitor C4 may be connected between the LLC resonant module 12 and the voltage regulating module 11. The fourth capacitor C4 may be used for voltage regulation.

Illustratively, in S30, after the absolute value of the output voltage of the DC/DC converter decreases to the second voltage threshold, the DC/DC converter is controlled to switch from the operating state to the bypass state.

In some embodiments, as shown in fig. 4, the control method of the DC/DC converter provided in the embodiment of the present application may further include S40.

S40, if the absolute value of the output voltage is smaller than or equal to the first voltage threshold value, the DC/DC converter is controlled to be switched to a bypass state.

Under the condition that the absolute value of the output voltage of the DC/DC converter is smaller than or equal to the second voltage threshold value, the overcurrent problem of the DC/DC converter is not triggered, the absolute value of the output voltage of the DC/DC converter can be directly controlled to be switched from the working state to the bypass state instead of being reduced, and therefore the switching efficiency of the DC/DC converter can be guaranteed while the reliability of the DC/DC converter is guaranteed.

In some embodiments, as shown in fig. 3, the DC/DC converter as introduced above comprises a voltage regulation module 11, the voltage regulation module 11 comprising three branches in parallel, each branch comprising an upper switching tube and a lower switching tube in series. In order to ensure reliability of the DC/DC converter, the bypass states of the DC/DC converter may include a primary bypass state and a secondary bypass state. In the first-stage bypass state, upper switching tubes in each branch of the voltage regulating module 11 are turned on, and lower switching tubes in each branch of the voltage regulating module 11 are turned off; in the secondary bypass state, both the upper and lower switching tubes in each branch of the voltage regulation module 11 are turned on.

As shown in fig. 3, in the first-stage bypass state, the upper switching transistors Q1, Q3, Q5 in the voltage adjustment module 11 are all turned on, and the lower switching transistors Q2, Q4, Q6 in the voltage adjustment module 11 are all turned off. In the two-stage bypass state, the switching transistors Q1, Q3, Q5, Q2, Q4, Q6 of the voltage regulating module 11 are all turned on.

In some embodiments, controlling the DC/DC converter in S30 to switch to the bypass state may include: the DC/DC converter is controlled to be switched to a first-stage bypass state and then switched to a second-stage bypass state from the first-stage bypass state.

As shown in fig. 5, after receiving the request for switching the bypass state, if the DC/DC converter is directly switched from the operating state to the secondary bypass state, the fourth capacitor C4 between the LLC resonant module 12 and the voltage regulating module 11 and the switching transistors Q1 and Q2 form a loop (as shown by the arrow in fig. 5), and the fourth capacitor C4 is shorted, which is easy to cause a current spike, and even damage the devices of the voltage regulating module 11. In the embodiment of the application, the DC/DC converter is controlled to be switched to the first-stage bypass state and then switched to the second-stage bypass state, so that the short circuit of the fourth capacitor C4 can be avoided, the current peak is avoided, and the reliability of the DC/DC converter is improved.

As shown in fig. 6, after receiving the request for switching the bypass state, the DC/DC converter is switched from the operating state to the first-stage bypass state, and the upper switching transistors Q3 and Q5 and the first capacitor C1 form a loop (as indicated by the arrow in fig. 6), so that if the absolute value of the output voltage at the low-voltage output side of the DC/DC converter is large, a hardware overcurrent phenomenon is likely to occur. In the embodiment of the application, when the absolute value of the output voltage of the DC/DC converter in the working state is larger, the absolute value of the output voltage of the DC/DC converter is reduced, and after the absolute value of the output voltage of the DC/DC converter is reduced to meet the threshold requirement, the DC/DC converter is controlled to be switched from the working state to the primary bypass state, so that the overcurrent problem that the DC/DC converter is switched from the working state to the primary bypass state can be solved.

When the DC/DC converter is in the operating state, the LLC resonant module 12 is in the operating state, and the voltage regulating module 11 is also in the operating state. With the DC/DC converter in either the primary bypass state or the secondary bypass state, the LLC resonant module 12 is in an operational state. For example, a PWM signal may be sent to a transistor of the LLC resonant module 12 to control the LLC resonant module 12 to be in an operational state.

As an example, as shown in fig. 7, the control method of the DC/DC converter provided by the embodiment of the present application may include S71 to S75.

S71, obtaining the output voltage of the DC/DC converter in the working state.

S72, judging whether the absolute value of the output voltage is larger than a first voltage threshold. If yes, S73 is executed, and if no, S74 is executed.

S73, reducing the absolute value of the output voltage of the DC/DC converter, and reducing the absolute value of the output voltage of the DC/DC converter to be less than or equal to a second voltage threshold.

S74, controlling the DC/DC converter to enter a first-stage bypass state.

S75, controlling the DC/DC converter to enter a secondary bypass state.

Based on the same inventive concept, the embodiment of the application also provides a battery system. As shown in fig. 2, the battery system 100 may include a controller 20, a plurality of battery clusters 30 connected in parallel, and a DC/DC converter 10 connected to the battery clusters 30. The controller 20 is connected to the DC/DC converter 10.

A controller 20, configured to obtain an output voltage of the DC/DC converter in the operating state, and if the absolute value of the output voltage is greater than a first voltage threshold, control the absolute value of the output voltage of the DC/DC converter to decrease, and if the absolute value of the output voltage of the DC/DC converter decreases to be less than or equal to a second voltage threshold, control the DC/DC converter to switch to the bypass state; wherein the second voltage threshold is less than or equal to the first voltage threshold.

According to the battery system provided by the embodiment of the application, if the absolute value of the output voltage of the DC/DC converter is larger than the first voltage threshold, the absolute value of the output voltage of the DC/DC converter is firstly reduced to the second voltage threshold, and then the DC/DC converter is controlled to be switched from the working state to the bypass state. Therefore, the DC/DC converter can be prevented from being directly switched to the bypass state under the condition that the absolute value of the output voltage is large, the possibility of overcurrent of the DC/DC converter can be reduced, and the reliability of the DC/DC converter is improved.

The battery system disclosed by the embodiment of the application can be used in electric devices such as vehicles, ships or aircrafts, and is not limited to charging equipment for various electric devices.

In an embodiment of the present application, each battery cluster 30 may include a plurality of batteries connected in series. Batteries include, but are not limited to, lithium ion batteries, lithium metal batteries, lead acid batteries, nickel-metal hydride batteries, lithium sulfur batteries, lithium air batteries, or sodium ion batteries, without limitation. The battery may be a single cell, a battery module or a battery pack, and is not limited herein.

The circuit structure of the DC/DC converter 10 in the battery system disclosed in the embodiment of the present application may include, but is not limited to, the circuit structure of the DC/DC converter as shown in fig. 3.

For example, the controller 20 may be a chip or circuit that performs the relevant actions in accordance with the characteristic instructions. For example, the controller 20 may be a micro-control unit (Microcontroller Unit, MCU), but also a digital signal controller (Digital Signal Processor, DSP), an application specific integrated circuit (Application Specific-Integrated Circuit, ASIC), a Field-programmable gate array (Field-Programmable Gate Array, FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware components, or the like. For another example, the controller 20 may include an external clock, a random access Memory (Random Access Memory, RAM), a Read-Only Memory (ROM), and the like. The specific structure of the controller 20 is not limited in the present application.

In some embodiments, the controller 20 is further configured to: and if the absolute value of the output voltage of the DC/DC converter is smaller than or equal to the first voltage threshold value, controlling the DC/DC converter to switch to a bypass state.

In some embodiments, as shown in fig. 3, the DC/DC converter 10 includes a voltage regulation module 11, the voltage regulation module 11 including three branches in parallel, each branch including an upper switching tube and a lower switching tube in series. The specific structure of the voltage adjustment module 11 may be referred to the description of the above embodiment, and the description thereof will not be repeated here.

The bypass states of the DC/DC converter 10 include a primary bypass state and a secondary bypass state; the upper switching tube and the lower switching tube in each branch are conducted in the first-stage bypass state, and the lower switching tube in each branch is turned off in the second-stage bypass state.

The controller 20 for controlling the DC/DC converter to switch to the bypass state may include: the controller 20 is configured to control the DC/DC converter 10 to switch to the first-stage bypass state and then switch from the first-stage bypass state to the second-stage bypass state.

In the embodiment of the application, the DC/DC converter is controlled to be switched to the first-stage bypass state and then switched to the second-stage bypass state, so that the short circuit of the fourth capacitor C4 can be avoided, the current spike is avoided, and the reliability of the DC/DC converter is improved.

In addition, when the absolute value of the output voltage of the DC/DC converter in the working state is large, the absolute value of the output voltage of the DC/DC converter is reduced, and after the absolute value of the output voltage of the DC/DC converter is reduced to meet the threshold requirement, the DC/DC converter is controlled to be switched from the working state to the primary bypass state, so that the overcurrent problem that the DC/DC converter is switched from the working state to the primary bypass state can be solved.

In some embodiments, as shown in fig. 3, the DC/DC converter includes a voltage regulation module 11, the voltage regulation module 11 includes a switching tube, and the controller 20 is configured to reduce an absolute value of an output voltage of the DC/DC converter, including: the controller 20 is configured to reduce the duty cycle of the control signal of the switching tube to reduce the absolute value of the output voltage of the DC/DC converter, wherein the smaller the duty cycle of the control signal of the switching tube is, the smaller the absolute value of the output voltage of the DC/DC converter is.

As introduced above, the voltage regulation module 11 may be a bi-directional buck-boost voltage regulation module. When the lower switching tube Q2 is turned off, the upper switching tube Q1, the diode D2 and the first inductor L1 form a first buck type voltage reducing circuit; when the lower switching tube Q4 is turned off, the upper switching tube Q3, the diode D4 and the second inductor L2 form a second buck type voltage-reducing circuit. The first buck voltage-reducing circuit and the second buck voltage-reducing circuit are connected in parallel to realize power supply to the later-stage load.

The controller 20 may be configured to control the lower switching transistor Q2 and the lower switching transistor Q4 to be turned off, and reduce the duty ratio of the control signals of the upper switching transistor Q1 and the upper switching transistor Q3, so as to reduce the absolute value of the output voltage of the DC/DC converter.

The controller 20 may output a control signal to each switching tube of the DC/DC converter to control the switching tube to be turned on or off.

Illustratively, as shown in fig. 2, the multi-cluster battery clusters are connected in parallel and connected to a DC/AC (Direct Current/Alternating Current) converter at the output. Alternatively, the multi-cluster battery clusters are connected in parallel and connected to a PCS (Power Conversion System, energy storage converter) or a load at the output.

For example, as shown in fig. 2, the battery system 100 may further include a first switch K1, a second switch K2, a third switch K3, and a first resistor R1. One end of each of the battery clusters 30 is connected to the second bus bar 32 through a first switch, respectively. The second switch K2 and the first resistor R1 are connected in series and then connected in parallel with the third switch K3 to the third node N3 and the other end of the battery cluster 30.

For example, the first bus bar 31 may serve as a positive bus bar and the second bus bar 32 may serve as a negative bus bar.

For example, in the case of pre-charging the battery cluster 30, the first switch K1, the second switch K2 may be controlled to be turned on, and the third switch K3 may be controlled to be turned off. After the pre-charging is finished, the first switch K1 and the third switch K3 can be controlled to be turned on, and the second switch K2 is controlled to be turned off.

Based on the same inventive concept, the embodiment of the application also provides a control device of the DC/DC converter. As shown in fig. 8, the control device 200 may include a voltage acquisition module 201, a step-down control module 202, and a switching control module 203.

A voltage acquisition module 201 for acquiring an output voltage of the DC/DC converter;

a step-down control module 202, configured to control the absolute value of the output voltage of the DC/DC converter to be reduced if the absolute value of the output voltage is greater than a first voltage threshold;

and a switching control module 203, configured to control the DC/DC converter to switch to the bypass state when the absolute value of the output voltage of the DC/DC converter decreases to be less than or equal to a second voltage threshold, where the second voltage threshold is less than or equal to the first voltage threshold.

According to the control device for the DC/DC converter provided by the embodiment of the application, if the absolute value of the output voltage of the DC/DC converter is larger than the first voltage threshold value, the absolute value of the output voltage of the DC/DC converter is firstly reduced to the second voltage threshold value, and then the DC/DC converter is controlled to be switched from the working state to the bypass state. Therefore, the DC/DC converter can be prevented from being directly switched to the bypass state under the condition that the absolute value of the output voltage is large, the possibility of overcurrent of the DC/DC converter can be reduced, and the reliability of the DC/DC converter is improved.

In some embodiments, the switching control module 203 is further configured to control the DC/DC converter to switch to the bypass state if the absolute value of the output voltage is less than or equal to the first voltage threshold.

In some embodiments, the DC/DC converter includes a voltage regulation module including three branches connected in parallel, each branch including an upper switching tube and a lower switching tube connected in series, the bypass state including a primary bypass state and a secondary bypass state;

the handover control module 203 may be configured to: the DC/DC converter is controlled to be switched to a first-stage bypass state firstly, and then, the first-stage bypass state is switched to a second-stage bypass state, wherein in the first-stage bypass state, an upper switching tube in each branch is conducted, a lower switching tube in each branch is turned off, and in the second-stage bypass state, the upper switching tube and the lower switching tube in each branch are conducted.

In some embodiments, the DC/DC converter includes a voltage regulation module including a switching tube, and the buck control module 202 is operable to: the duty ratio of the control signal of the switching tube is reduced to reduce the absolute value of the output voltage of the DC/DC converter, wherein the smaller the duty ratio of the control signal of the switching tube is, the smaller the absolute value of the output voltage of the DC/DC converter is.

For specific limitations on the control device of the DC/DC converter, reference may be made to the above limitations on the control method of the DC/DC converter, and no further description is given here. The respective modules in the control device of the DC/DC converter described above may be implemented in whole or in part by software, hardware, and combinations thereof. The above modules may be embedded in hardware or may be independent of a processor in the electronic device, or may be stored in software in a memory in the electronic device, so that the processor may call and execute operations corresponding to the above modules.

Based on the same inventive concept, the embodiment of the application also provides electronic equipment.

Fig. 9 shows a schematic hardware structure of an electronic device according to an embodiment of the present application.

A processor 901 may be included in an electronic device, as well as a memory 902 in which computer program instructions are stored.

In particular, the processor 901 may include a Central Processing Unit (CPU), or an application specific integrated circuit (Application Specific Integrated Circuit, ASIC), or may be configured as one or more integrated circuits that implement embodiments of the present application.

Memory 902 may include mass storage for data or instructions. By way of example, and not limitation, the memory 902 may comprise a Hard Disk Drive (HDD), floppy Disk Drive, flash memory, optical Disk, magneto-optical Disk, magnetic tape, or universal serial bus (Universal Serial Bus, USB) Drive, or a combination of two or more of the foregoing. The memory 902 may include removable or non-removable (or fixed) media, where appropriate. The memory 902 may be internal or external to the integrated gateway disaster recovery device, where appropriate. In a particular embodiment, the memory 902 is a non-volatile solid state memory.

In a particular embodiment, the memory 902 includes Read Only Memory (ROM). The ROM may be mask programmed ROM, programmable ROM (PROM), erasable PROM (EPROM), electrically Erasable PROM (EEPROM), electrically rewritable ROM (EAROM), or flash memory, or a combination of two or more of these, where appropriate. By way of example, the memory may include non-volatile transient memory.

The processor 901 implements the control method of any one of the DC/DC converters of the above-described embodiments by reading and executing the computer program instructions stored in the memory 902.

In one example, electronic device 900 may also include communication interface 903 and bus 910. As shown in fig. 9, the processor 901, the memory 902, and the communication interface 903 are connected to each other via a bus 910, and communicate with each other.

The communication interface 903 is mainly used to implement communication between each module, device, unit, and/or apparatus in the embodiment of the present invention.

Bus 910 includes hardware, software, or both that couple components of an electronic device to each other. By way of example, and not limitation, the buses may include an Accelerated Graphics Port (AGP) or other graphics bus, an Enhanced Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), a HyperTransport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an infiniband interconnect, a Low Pin Count (LPC) bus, a memory bus, a micro channel architecture (MCa) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a video electronics standards association local (VLB) bus, or other suitable bus, or a combination of two or more of the above. Bus 910 may include one or more buses, where appropriate. Although embodiments of the invention have been described and illustrated with respect to a particular bus, the invention contemplates any suitable bus or interconnect.

By way of example, the electronic device may be a cell phone, tablet computer, notebook computer, palm top computer, vehicle mounted electronic device, ultra-mobile personal computer (UMPC), netbook or personal digital assistant (personal digital assistant, PDA), or the like.

The electronic device may perform the control method of the DC/DC converter in the embodiment of the present application, thereby implementing the control method of the DC/DC converter and the control apparatus of the DC/DC converter described in connection with fig. 1 and 8.

The embodiment of the application also provides a computer readable storage medium, on which a computer program is stored, which when executed by a processor, can implement the control method of the DC/DC converter in the above embodiment, and achieve the same technical effects, and in order to avoid repetition, the description is omitted here. The computer readable storage medium may include, but is not limited to, read-Only Memory (ROM), random access Memory (Random Access Memory, RAM), magnetic or optical disk.

According to some embodiments of the present application, there is also provided a computer program product, which, when executed by a processor, can implement the above-mentioned method. The computer program product includes one or more computer instructions. When loaded and executed on a computer, these computer instructions may implement some or all of the methods described above, in whole or in part, in accordance with the processes or functions described in embodiments of the present disclosure.

The functional blocks shown in the above-described structural block diagrams may be implemented in hardware, software, firmware, or a combination thereof. When implemented in hardware, it may be, for example, an electronic circuit, an Application Specific Integrated Circuit (ASIC), suitable firmware, a plug-in, a function card, or the like. When implemented in software, the elements of the application are the programs or code segments used to perform the required tasks. The program or code segments may be stored in a machine readable medium or transmitted over transmission media or communication links by a data signal carried in a carrier wave. "computer-readable medium" may include any medium capable of storing or transmitting information. Examples of a computer readable medium include an electronic circuit, a semiconductor memory device, a ROM, a flash memory, an Erasable ROM (EROM), a floppy disk, a CD-ROM, an optical disk, a hard disk, a fiber optic medium, a radio frequency link, and so forth. The code segments may be downloaded via computer networks such as the internet, intranets, etc.

According to embodiments of the application, the computer-readable storage medium may be a non-transitory computer-readable storage medium.

In the embodiments shown in the above figures, the resistor is represented by a single resistor, and the capacitor is represented by a single capacitor. In other embodiments, the resistor may be an integration of series, parallel or series-parallel resistors, and the capacitor may be an integration of series, parallel or series-parallel capacitors. Specific parameters of each device can be set according to actual requirements, and the application is not limited to this.

It should also be noted that the exemplary embodiments mentioned in this disclosure describe some methods or systems based on a series of steps or devices. However, the present application is not limited to the order of the above-described steps, that is, the steps may be performed in the order mentioned in the embodiments, or may be performed in a different order from the order in the embodiments, or several steps may be performed simultaneously.

Aspects of the present application are described above with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, enable the implementation of the functions/acts specified in the flowchart and/or block diagram block or blocks. Such a processor may be, but is not limited to being, a general purpose processor, a special purpose processor, an application specific processor, or a field programmable logic circuit. It will also be understood that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware which performs the specified functions or acts, or combinations of special purpose hardware and computer instructions.

These embodiments are not exhaustive of all details, nor are they intended to limit the application to the precise embodiments disclosed, in accordance with the application. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the application and the practical application, to thereby enable others skilled in the art to best utilize the application and various modifications as are suited to the particular use contemplated. The application is limited only by the claims and the full scope and equivalents thereof.

Claims

1. A control method of a DC/DC converter, comprising:

acquiring the output voltage of the DC/DC converter;

if the absolute value of the output voltage is larger than a first voltage threshold value, reducing the absolute value of the output voltage of the DC/DC converter;

and controlling the DC/DC converter to switch to a bypass state under the condition that the absolute value of the output voltage of the DC/DC converter is reduced to be smaller than or equal to a second voltage threshold value, wherein the second voltage threshold value is smaller than or equal to the first voltage threshold value.

2. The method of claim 1, wherein after the obtaining the output voltage of the DC/DC converter, the method further comprises: and if the absolute value of the output voltage is smaller than or equal to the first voltage threshold value, controlling the DC/DC converter to switch to a bypass state.

3. The method of claim 1 or 2, wherein the DC/DC converter comprises a voltage regulation module comprising three branches in parallel, each branch comprising an upper switching tube and a lower switching tube in series, the bypass state comprising a primary bypass state and a secondary bypass state;

the controlling the DC/DC converter to switch to a bypass state includes:

and controlling the DC/DC converter to be firstly switched to the primary bypass state and then switched to the secondary bypass state from the primary bypass state, wherein in the primary bypass state, the upper switching tube in each branch is conducted, the lower switching tube in each branch is turned off, and in the secondary bypass state, the upper switching tube and the lower switching tube in each branch are conducted.

4. The method according to claim 1 or 2, wherein the DC/DC converter comprises a voltage regulation module comprising a switching tube, the reducing the absolute value of the output voltage of the DC/DC converter comprising:

and reducing the duty ratio of the control signal of the switching tube to reduce the absolute value of the output voltage of the DC/DC converter, wherein the smaller the duty ratio of the control signal of the switching tube is, the smaller the absolute value of the output voltage of the DC/DC converter is.

5. A battery system, characterized in that the battery system comprises a controller, a plurality of parallel battery clusters and a DC/DC converter connected with the battery clusters, and the controller is connected with the DC/DC converter;

the controller is configured to obtain an output voltage of the DC/DC converter in a working state, if the absolute value of the output voltage is greater than a first voltage threshold, control the absolute value of the output voltage of the DC/DC converter to decrease, and if the absolute value of the output voltage of the DC/DC converter decreases to be less than or equal to a second voltage threshold, control the DC/DC converter to switch to a bypass state; wherein the second voltage threshold is less than or equal to the first voltage threshold.

6. The battery system of claim 5, wherein the controller is further configured to:

and if the absolute value of the output voltage is smaller than or equal to the first voltage threshold value, controlling the DC/DC converter to switch to a bypass state.

7. The battery system of claim 5 or 6, wherein the DC/DC converter comprises a voltage regulation module comprising three branches in parallel, each branch comprising an upper switching tube and a lower switching tube in series, the bypass state comprising a primary bypass state and a secondary bypass state;

The controller is configured to control the DC/DC converter to switch to a bypass state, and includes:

the controller is configured to control the DC/DC converter to switch to the first-stage bypass state first, and then switch from the first-stage bypass state to the second-stage bypass state, where in the first-stage bypass state, the upper switching tube in each branch is turned on, the lower switching tube in each branch is turned off, and in the second-stage bypass state, the upper switching tube and the lower switching tube in each branch are both turned on.

8. The battery system according to claim 5 or 6, wherein the DC/DC converter includes a voltage regulation module including a switching tube, the controller for reducing an absolute value of an output voltage of the DC/DC converter, comprising:

9. A control device for a DC/DC converter, comprising:

and the switching control module is used for controlling the DC/DC converter to switch to a bypass state under the condition that the absolute value of the output voltage of the DC/DC converter is reduced to be smaller than or equal to a second voltage threshold value, wherein the second voltage threshold value is smaller than or equal to the first voltage threshold value.

10. An electronic device, comprising: a processor and a memory storing computer program instructions;

the processor, when executing the computer program instructions, implements a method of controlling a DC/DC converter as claimed in any one of claims 1 to 4.

11. A computer readable storage medium, characterized in that the computer readable storage medium has stored thereon computer program instructions, which when executed by a processor, implement a method of controlling a DC/DC converter according to any of claims 1 to 4.