Control method and device of direct current converter, electronic equipment and storage medium

Abstract

The invention relates to the technical field of direct-current converters, and discloses a control method and device of a direct-current converter, electronic equipment and a storage medium, the direct-current converter comprises a plurality of direct-current conversion units which are connected in parallel, and the method comprises the following steps: determining a control signal of each switching tube in the direct-current conversion units; for different direct current conversion units, a preset phase difference is set between the control signals of the same switching tube; and according to the control signal of each switch tube in the DC conversion unit, controlling the on-off of the corresponding switch tube. When the same switching tube of different direct current conversion units is controlled, the control signals with certain phase difference are used for controlling, so that inductors in different direct current conversion units can be charged and discharged asynchronously, the current ripples of the inductors can be reduced, and the size and the weight of the inductors can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of direct current converters, and in particular to a control method, a device, an electronic device and a storage medium for a direct current converter. Background Art

[0002] A DC-DC converter (i.e., a DC-DC converter or DCDC converter), also known as a DC converter, is a voltage converter that converts a DC power source into other voltage types. DCDC converters are divided into boost DCDC converters, buck DCDC converters, and buck-boost DCDC converters. DCDC converters are widely used in various power usage scenarios, such as photovoltaic systems, new energy vehicle charging, and other uninterrupted charging scenarios.

[0003] Commonly used buck-boost DCDC converters are generally inductive energy storage types, but when used in high-power scenarios such as new energy vehicles, it will cause large inductor current ripple. Summary of the invention

[0004] In view of this, the present invention provides a control method, device, electronic device and storage medium of a DC converter, so as to reduce the inductor current ripple.

[0005] In a first aspect, the present invention provides a control method for a DC converter, wherein the DC converter comprises: a plurality of DC conversion units, and the DC conversion units comprise: a first switch tube, a second switch tube, a third switch tube, a fourth switch tube and an inductor, and the second end of the first switch tube is connected to the first end of the second switch tube and to one end of the inductor; the second end of the third switch tube is connected to the first end of the fourth switch tube and to the other end of the inductor;

[0006] The first switch tubes of each of the DC conversion units share a first end and serve as the first access end of the DC converter; the third switch tubes of each of the DC conversion units share a second end and serve as the second access end of the DC converter; the third switch tubes and the fourth switch tubes of each of the DC conversion units share a second end;

[0007] The method comprises:

[0008] Determine the control signal of each switch tube in the DC conversion unit; for different DC conversion units, a preset phase difference is set between the control signals of the same switch tube;

[0009] According to the control signal of each switch tube in the DC conversion unit, the corresponding switch tube is controlled to be turned on and off.

[0010] In a second aspect, the present invention provides a control device for a DC converter, wherein the DC converter comprises: a plurality of DC conversion units, and the DC conversion units comprise: a first switch tube, a second switch tube, a third switch tube, a fourth switch tube and an inductor, and the second end of the first switch tube is connected to the first end of the second switch tube and to one end of the inductor; the second end of the third switch tube is connected to the first end of the fourth switch tube and to the other end of the inductor;

[0011] The first switch tubes of each of the DC conversion units share a first end and serve as the first access end of the DC converter; the third switch tubes of each of the DC conversion units share a second end and serve as the second access end of the DC converter; the third switch tubes and the fourth switch tubes of each of the DC conversion units share a second end;

[0012] The device comprises:

[0013] A signal module, used to determine the control signal of each switch tube in the DC conversion unit; for different DC conversion units, a preset phase difference is set between the control signals of the same switch tube;

[0014] The control module is used to control the on and off of the corresponding switch tube according to the control signal of each switch tube in the DC conversion unit.

[0015] In a third aspect, the present invention provides an electronic device, comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the control method of a DC converter according to the first aspect or any corresponding embodiment thereof by executing the computer instructions.

[0016] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the control method for a DC converter according to the first aspect or any corresponding embodiment thereof.

[0017] In a fifth aspect, the present invention provides a computer program product, comprising computer instructions for causing a computer to execute the control method of a DC converter according to the first aspect or any corresponding embodiment thereof.

[0018] The present invention sets a plurality of parallel DC conversion units for the DC converter, and controls the on and off of the switch tube in each DC conversion unit respectively to realize DC conversion; and when controlling the same switch tube of different DC conversion units, the control is performed with a control signal with a certain phase difference, so that the inductors in different DC conversion units can be charged and discharged at different times, which can not only reduce the inductor current ripple, but also reduce the volume and weight of the inductor. In addition, the requirements for each switch tube are also reduced, which is conducive to reducing the weight and volume of the product and reducing the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the related technologies, the drawings required for use in the specific embodiments or the related technical descriptions will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 is a structural schematic diagram of a buck-boost DCDC converter according to an embodiment of the present invention;

[0021] Figure 2 yes Figure 1 The schematic diagram of the inductor current waveform of the buck-boost DCDC converter shown;

[0022] Figure 3 is a structural schematic diagram of a DC converter according to an embodiment of the present invention;

[0023] Figure 4 is a flow chart of a control method of a DC converter according to an embodiment of the present invention;

[0024] Figure 5 is a flow chart of another control method of a DC converter according to an embodiment of the present invention;

[0025] Figure 6 is a first principle schematic diagram of a DC converter according to an embodiment of the present invention;

[0026] Figure 7 yes Figure 6 A control signal timing diagram of the DC converter shown;

[0027] Figure 8 is a second principle schematic diagram of a DC converter according to an embodiment of the present invention;

[0028] Fig. 9 yes Figure 8 A control signal timing diagram of the DC converter shown;

[0029] Fig.10is a third principle schematic diagram of a DC converter according to an embodiment of the present invention;

[0030] Fig.11 yes Fig.10 A control signal timing diagram of the DC converter shown;

[0031] Fig.12 is a fourth principle schematic diagram of a DC converter according to an embodiment of the present invention;

[0032] Fig.13 yes Fig.12 A control signal timing diagram of the DC converter shown;

[0033] Fig.14 is a structural block diagram of a control device for a DC converter according to an embodiment of the present invention;

[0034] Fig.15 It is a schematic diagram of the hardware structure of the electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0036] In scenarios such as new energy vehicles, there is often a need to charge between batteries, so a buck-boost DCDC converter is generally used. Common buck-boost DCDC converters use inductive energy storage, such as Figure 1 As shown, it is a structural schematic diagram of an H-bridge type buck-boost DCDC converter, which controls the on and off of four high-frequency switching tubes (switching power tubes) Q1 / Q2 / Q3 / Q4 to make the inductor L1 continuously store / discharge energy and finally achieve a stable voltage / current output. At the same time, it can achieve a bidirectional boost / buck function, that is, the two batteries Bat on the left and right sides can charge and discharge each other.

[0037] However, when used in high-power scenarios, the DCDC converter has a large current ripple variation in the continuous mode due to the large inductance of the inductor L1. Figure 2 As shown, the entire control cycle T includes an on-time Ton and an off-time Toff, and the inductor current IL has a large ripple. Compared with the output current Io, its current ripple ratio can reach 40%, that is, the change value ΔL of the inductor current IL is approximately 40% Io.

[0038] In this case, it is necessary to increase the volume of the inductor and take heat dissipation measures to reduce the loss and the temperature. In addition, the use of high power also requires the selection of switch tubes with greater stress and stronger current capacity, which makes the volume, weight and cost of the entire DCDC converter high. The volume of inductor L1 can even occupy 1 / 3 of the entire DCDC converter space. Especially with the rapid development of new energy vehicles, small volume, low weight and cost reduction of automotive parts are important parts of product design requirements, which do not meet current needs.

[0039] A control method for a DC converter provided by an embodiment of the present invention provides a plurality of parallel DC conversion units for the DC converter, and controls the on and off of a switch tube in each DC conversion unit respectively to realize DC conversion; and when controlling the same switch tube of different DC conversion units, control is performed with a control signal with a certain phase difference, so that the inductors in the different DC conversion units can be charged and discharged at different times, which can not only reduce the inductor current ripple, but also reduce the volume and weight of the inductor.

[0040] According to an embodiment of the present invention, a control method embodiment of a DC converter is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0041] In this embodiment, a control method of a DC converter is provided, which can be used for a controller of a DC converter. The DC converter includes: a plurality of DC conversion units, and the DC conversion units include: a first switch tube, a second switch tube, a third switch tube, a fourth switch tube and an inductor. Each DC conversion unit has the same structure.

[0042] Figure 3 FIG. 1 shows a schematic diagram of the structure of the DC converter. Figure 3 As shown, the DC converter includes two DC conversion units, and the DC conversion unit includes four switch tubes and corresponding inductors. Specifically, as Figure 3 As shown, the first DC conversion unit includes a first switch tube Q1, a second switch tube Q3, a third switch tube Q5, a fourth switch tube Q7 and an inductor L1, and the second DC conversion unit includes a first switch tube Q2, a second switch tube Q4, a third switch tube Q6, a fourth switch tube Q8 and an inductor L2.

[0043] Furthermore, the second end of the first switch tube is connected to the first end of the second switch tube and to one end of the inductor; the second end of the third switch tube is connected to the first end of the fourth switch tube and to the other end of the inductor. The first switch tubes of each DC conversion unit share a first end and serve as the first access end of the DC converter; the third switch tubes of each DC conversion unit share a second end and serve as the second access end of the DC converter; the third switch tubes and the fourth switch tubes of each DC conversion unit share a second end.

[0044] like Figure 3 As shown, the port on the left side of the DC converter is used as the first access terminal, and the port on the right side of the DC converter is used as the second access terminal. Among them, for these two DC conversion units, the first switch tube Q1 of the first DC conversion unit and the first switch tube Q2 of the second DC conversion unit share the first end (that is, the two first ends are connected), and serve as the first access terminal on the left side of the DC converter. For example, the first access terminal can be connected to the positive electrode of the first battery Bat1. Similarly, the third switch tube Q5 of the first DC conversion unit and the third switch tube Q6 of the second DC conversion unit also share the first end, and serve as the second access terminal on the right side of the DC converter. For example, the second access terminal can be connected to the positive electrode of the second battery Bat2.

[0045] The second switch tube Q3 and the fourth switch tube Q7 of the first DC conversion unit, and the second switch tube Q4 and the fourth switch tube Q8 of the second DC conversion unit, these switch tubes share a second end (that is, these four second ends are connected) to form a power supply loop; Figure 3 As shown, the second ends of these switch tubes are all grounded.

[0046] For each DC conversion unit, two switch tubes form one bridge arm, and the other two switch tubes form another bridge arm, and the inductor is located between the two bridge arms. Figure 3 Taking the first DC conversion unit in as an example, the second end of the first switch tube Q1 is connected to the first end of the second switch tube Q3 to form a bridge arm, and the second end of the third switch tube Q5 is connected to the first end of the fourth switch tube Q7 to form another bridge arm; the two ends of the inductor L1 are respectively connected to the connection points of the two switch tubes in the two bridge arms.

[0047] For example, each switch tube can be a field effect tube (MOS), the first end of the switch tube is the drain, and the second end of the switch tube is the source. By controlling the gate voltage of each switch tube, the on-off control of the switch tube can be achieved.

[0048] Figure 4 is a flow chart of a control method of a DC converter according to an embodiment of the present invention. Figure 4 As shown, the process includes the following steps.

[0049] Step S401, determining the control signal of each switch tube in the DC conversion unit; for different DC conversion units, a preset phase difference is set between the control signals of the same switch tube.

[0050] In this embodiment, in order to control the operation of the DC converter, it is necessary to determine the signal for controlling the on and off of each switch tube, that is, the control signal. The control signal may be a PWM (Pulse Width Modulation) signal.

[0051] The DC converter in this embodiment includes a plurality of DC conversion units, each of which is also provided with a corresponding inductor, so the current of the entire DC converter is shunted by these inductors. In order to reduce the inductor current ripple, the control signals of the same switch tube are different for different DC conversion units, and a preset phase difference is provided between them. When the corresponding switch tube is controlled based on the control signal, the inductors of different DC conversion units may operate in different charge and discharge states. For example, one inductor is currently in a charging state, while another inductor is currently in a discharging state. The changes in the two inductor currents offset each other, thereby reducing the overall inductor current ripple.

[0052] by Figure 3 As shown in the figure, the switch tubes Q1 and Q2 are the same switch tubes belonging to different DC conversion units, and both are first switch tubes. Therefore, there is a certain phase difference between the control signals set for the first switch tube Q1 and the first switch tube Q2, so that the charging and discharging states of the inductor L1 and the inductor L2 can be staggered, and finally the ripple of the overall inductor current can be reduced.

[0053] It can be understood that the switch tubes Q3 and Q4 are both the same second switch tube, the switch tubes Q5 and Q6 are both the same third switch tube, and the switch tubes Q7 and Q8 are both the same fourth switch tube. The control signals set for these switch tubes also have corresponding preset phase differences, which will not be elaborated here.

[0054] Among them, since there may be more than two DC conversion units, in order to ensure that there is a certain phase difference between the control signals of the same type of switch tube of each DC conversion unit, these DC conversion units can be arranged in a cycle, and for any two adjacent DC conversion units, a suitable preset phase difference is set between the control signals of the same type of switch tube.

[0055] Step S402, controlling the on and off of corresponding switch tubes according to the control signals of the switch tubes in the DC conversion unit.

[0056] In this embodiment, after the control signal of each switch tube in the DC conversion unit is determined, the on and off of the corresponding switch tube can be controlled based on each control signal. Figure 3As shown, taking the first switch tube Q1 as an example, its control signal is a PWM signal composed of high and low levels. Based on the control signal, the gate voltage of the first switch tube Q1 can be controlled, thereby controlling the first switch tube Q1 to be turned on or off.

[0057] The control method of the DC converter provided in this embodiment is to set a plurality of parallel DC conversion units for the DC converter, respectively control the on and off of the switch tube in each DC conversion unit to realize DC conversion; and when controlling the same switch tube of different DC conversion units, control is performed with a control signal with a certain phase difference, so that the inductors in different DC conversion units can be charged and discharged at different times, which can not only reduce the inductor current ripple, but also reduce the volume and weight of the inductor. In addition, the requirements for each switch tube are also reduced, which is conducive to reducing the weight and volume of the product and reducing the cost.

[0058] Moreover, this method can be applied to high-power scenarios such as new energy vehicles. For example, it can be applied to charging and discharging between land vehicle batteries, or between land vehicle batteries and aircraft batteries, and has a wide range of applications.

[0059] In this embodiment, a control method of a DC converter is provided, which can be used in a controller of a DC converter. Figure 3 The DC converter shown in the figure will not be described in detail here. Figure 5 is a flow chart of a control method of a DC converter according to an embodiment of the present invention. Figure 5 As shown, the process includes the following steps.

[0060] Step S501, determining the control signal of each switch tube in the DC conversion unit; for different DC conversion units, a preset phase difference is set between the control signals of the same switch tube.

[0061] In this embodiment, in order to minimize the inductor ripple, the preset phase difference for: Wherein, N is the number of DC conversion units.

[0062] For example, when N is 2, the preset phase difference is 180°; when N is 3, the preset phase difference is 120°. The larger N is, the better the ripple removal effect is, but it will lead to a complex structure and even increase the cost. Generally, N is 2 or 3. Figure 3 As shown, the DC converter includes two DC conversion units, ie, N=2.

[0063] When determining the control signal, the control signal of one switch tube can be mainly determined, and the control signals of other switch tubes can be adaptively set on this basis. For ease of description, the switch tube is called the main switch tube. Specifically, the above step S501 includes: the following steps S5011 to S5012.

[0064] Step S5011, determining a main switch tube and determining a main duty cycle of the main switch tube; the main switch tube is one of the first switch tube, the second switch tube, the third switch tube, and the fourth switch tube.

[0065] In this embodiment, the main switch tube, that is, the main switch tube, can be determined according to the demand for the DC converter; among them, the first switch tube, the second switch tube, the third switch tube, and the fourth switch tube may all be the main switch tubes, which is determined based on actual conditions.

[0066] Furthermore, in order to generate an accurate control signal for the main switch, it is necessary to determine the duty cycle of the main switch, that is, the main duty cycle. For example, the on-time and off-time of the main switch can be determined, and then the main duty cycle of the main switch can be calculated.

[0067] At a certain moment, for different DC conversion units, the main switch tubes are the same switch tube, for example, the main switch tubes of each DC conversion unit are all first switch tubes. Moreover, the main duty cycle of each main switch tube is the same, that is, only one main duty cycle needs to be determined.

[0068] Among them, for the same type of switch tube, the corresponding control signal has the same duty cycle, so as to simplify the control.

[0069] Step S5012, generating a main control signal of a DC conversion unit according to a main duty cycle; a preset phase difference is set between the main control signals of different DC conversion units; the main control signal of each DC conversion unit is used to control the on and off of the main switch tube of each DC conversion unit.

[0070] In this embodiment, after determining the main duty cycle of the main switch tube, a main control signal of each DC conversion unit can be generated based on the main duty cycle and the preset phase difference. The main control signal is used to control the main switch tube of the corresponding DC conversion unit.

[0071] Among them, after determining the main duty cycle of the main switch tube, the main control signal A of a DC conversion unit can be determined, and then the preset phase difference is shifted on the basis of the main control signal A to obtain the main control signal B of another DC conversion unit, and then the preset phase difference is shifted again on the basis of the main control signal B to obtain the main control signal C of another DC conversion unit, and so on.

[0072] In some optional implementations, other switch tubes except the main switch tube need to be coordinated and controlled. Specifically, the step S501 of "determining the control signal of each switch tube in the DC conversion unit" may also include the following steps.

[0073] Determine the auxiliary switch tube; the auxiliary switch tube is another switch tube belonging to the same bridge arm as the main switch tube.

[0074] Generate a sub-control signal of the DC conversion unit; the sub-control signal of the DC conversion unit is complementary to the main control signal of the DC conversion unit, and there is a dead time; the sub-control signal of each DC conversion unit is used to control the on and off of the sub-switch tube of each DC conversion unit.

[0075] In this embodiment, for any DC conversion unit, the switch tubes belonging to the same bridge arm as the main switch tube can be controlled in coordination. For ease of description, the switch tubes belonging to the same bridge arm as the main switch tube are referred to as auxiliary switch tubes. Figure 3 As shown, the first switch tube Q1 and the second switch tube Q3 belong to the same bridge arm. If the first switch tube Q1 is the main switch tube, the second switch tube Q3 is the auxiliary switch tube; conversely, if the second switch tube Q3 is the main switch tube, the first switch tube Q1 is the auxiliary switch tube. Other bridge arms are similar to this and will not be described in detail.

[0076] For the auxiliary switch tube, its control signal is called an auxiliary control signal, which is complementary to the main control signal, that is, when the main control signal is high, the auxiliary control signal is low; when the main control signal is low, the auxiliary control signal is high.

[0077] In addition, to avoid the main and auxiliary switches being turned on at the same time, a dead time is set between the main control signal and the auxiliary control signal. Specifically, there is a certain time interval from the main switch being disconnected (the main control signal changes from high level to low level) to the auxiliary switch being turned on (the auxiliary control signal changes from low level to high level); and there is also a certain time interval from the auxiliary switch being disconnected (the auxiliary control signal changes from high level to low level) to the main switch being turned on (the main control signal changes from low level to high level). By setting the time interval, it is possible to effectively avoid the main switch and the auxiliary switch being turned on at the same time.

[0078] Similar to the main control signal, the duty cycles of the auxiliary control signals of different DC conversion units are also the same. In addition, since the auxiliary control signal is complementary to the main control signal, when there is a preset phase difference between the main control signals, there is also a preset phase difference between different auxiliary control signals.

[0079] Optionally, step S501 “determine the control signal of each switch tube in the DC conversion unit” may also include: step A3.

[0080] Step A3, setting the control signal of the upper switch tube belonging to a different bridge arm from the main switch tube to a normally open signal, and setting the control signal of the lower switch tube belonging to a different bridge arm from the main switch tube to a normally closed signal; wherein the upper switch tube is the first switch tube or the third switch tube, and the lower switch tube is the second switch tube or the fourth switch tube.

[0081] In this embodiment, for the other bridge arm corresponding to the main switch tube and the auxiliary switch tube, which also includes two switch tubes, for the convenience of unified description, the switch tube in the upper part of the bridge arm is called the "upper switch tube", and the switch tube in the lower part of the bridge arm is called the "lower switch tube".

[0082] It can be understood that the upper switch tube may be the first switch tube or the third switch tube, and the lower switch tube may be the second switch tube or the fourth switch tube, which is determined based on actual conditions. If the upper switch tube is the first switch tube, the lower switch tube is the second switch tube; if the upper switch tube is the third switch tube, the lower switch tube is the fourth switch tube.

[0083] For the upper switch tube, its control signal is set to a normally open signal, for example, the normally open signal is a signal that is always at a high level (or, the duty cycle is 1), and the upper switch tube can be controlled to be always turned on based on the normally open signal. For the lower switch tube, its control signal is set to a normally closed signal, for example, the normally closed signal is a signal that is always at a low level (or, the duty cycle is 0), and the lower switch tube can be controlled to be always turned off based on the normally closed signal, which is equivalent to the circuit structure corresponding to the non-existence of the lower switch tube.

[0084] The normally open upper switch tube can always provide a circuit for the inductor charging and discharging process, ensuring that the DC converter can always output the corresponding voltage signal.

[0085] Among them, for different DC conversion units, each upper switch tube is normally open, and each lower switch tube is normally closed, so the control signals of each upper switch tube are the same, and the control signals of each upper switch tube are also the same. Since the control signal at this time is a normally open signal or a normally closed signal, the control signal itself remains unchanged after shifting any phase difference, so it can also be considered that there is a preset phase difference between these normally open signals or normally closed signals.

[0086] In this embodiment, based on the main control signal, the complementary auxiliary control signal can be simply and conveniently determined; and a dead time is provided between the main control signal and the auxiliary control signal, which can effectively avoid the main switch tube and the auxiliary switch tube from being turned on at the same time, and can ensure the stable operation of each DC conversion unit. The two switch tubes of the other bridge arm are set to be normally open and normally closed respectively, which can simplify the control of the other bridge arm.

[0087] In some optional implementations, which switch tube is used as the main switch is determined according to the current direction of the DC converter and the voltage across both ends.

[0088] Specifically, the above step of “determining the main switch tube” may include steps A1 to A4.

[0089] Step A1, when the DC converter discharges from the first access terminal to the second access terminal and the voltage of the first access terminal is higher than the voltage of the second access terminal, the first switch tube is used as the main switch tube. At this time, the second switch tube is the auxiliary switch tube, the third switch tube is the normally open upper switch tube, and the fourth switch tube is the normally closed lower switch tube.

[0090] Optionally, the above step of “determining the main duty cycle of the main switch tube” includes the following step B1.

[0091] Step B1, when the main switch tube is the first switch tube, the main duty cycle of the main switch tube is: Wherein, D1 is the main duty cycle, V1 is the voltage of the first access terminal, and V2 is the voltage of the second access terminal. At this time, the DC conversion unit is a forward buck circuit.

[0092] like Figure 3 As shown, if the power supply voltage of the first battery Bat1 is higher than the power supply voltage of the second battery Bat2, and the first battery Bat1 needs to discharge the power supply of the second battery Bat2, the first switch tube is used as the main switch tube. That is, the switch tubes Q1 and Q2 are the main switch tubes of the corresponding DC conversion unit. At this time, the working principle diagram of the DC converter can be seen in Figure 6 As shown in the figure (the upper part corresponds to the inductor charging, and the lower part corresponds to the inductor discharging), and the timing diagram of the control signal of each switch tube can be found in Figure 7 As shown. Figure 7 As shown, the third switch tubes Q5 and Q6 remain turned on, the fourth switch tubes Q7 and Q8 remain turned off, the timing between the first switch tubes Q1 and Q2 always maintains a phase difference of 180 degrees, and the timing between the second switch tubes Q3 and Q4 also always maintains a phase difference of 180 degrees.

[0093] like Figure 6 As shown, when the first switch tube Q1 is turned off, the second switch tube Q3 is turned on, which serves as a freewheeling switch tube for releasing the energy stored in the inductor L1. There is a dead time between the turning on of the second switch tube Q3 and the turning off of the first switch tube Q1, so as to avoid the short circuit caused by the simultaneous turning on of the first switch tube Q1 and the second switch tube Q3. For the DC conversion unit of another path, the first switch tube Q2 and the second switch tube Q4 are the same.

[0094] exist Figure 7In the timing diagram shown, at time T1, the first switch tube Q1 and the first switch tube Q2 are turned on, and the second switch tube Q3 and the second switch tube Q4 are turned off. At this time, the currents of the two paths flow from the first battery Bat1 through the inductor L1 and the inductor L2 to the second battery Bat2, and are stored in the inductor L1 and the inductor L2. At time T2, the first switch tube Q1 of one path is turned on, the second switch tube Q3 is turned off, the first switch tube Q2 of the two paths is turned off, and the second switch tube Q4 changes from open to closed and then to open. At this time, the current of one path flows through the first switch tube Q1, the inductor L1, and the third switch tube Q5 in sequence, and stores energy in the inductor L1. The current of the two paths flows through the second switch tube Q4, the inductor L2, and the third switch tube Q6 in sequence, and releases energy from the inductor L2 to the second battery Bat2.

[0095] At time T3, the first switch tube Q1 of one circuit is turned on, and the second switch tube Q3 is turned off. The first switch tube Q2 of the second circuit is turned on, and the second switch tube Q4 is turned off. This is the same as time T1. At this time, the currents of the two circuits flow from the first battery Bat1 through the inductor L1 and the inductor L2 to the second battery Bat2, and are stored in the inductor L1 and the inductor L2. At time T4, the first switch tube Q1 of one circuit is turned off, and the second switch tube Q3 is turned off, closed, and then turned off. The first switch tube Q2 of the second circuit is turned on, and the second switch tube Q4 is turned off. At this time, the current of one circuit flows through the second switch tube Q3, the inductor L1, and the third switch tube Q5 in sequence, releasing energy from the inductor L1 to the second battery Bat2. The current of the two circuits flows through the first switch tube Q2, the inductor L2, and the third switch tube Q6 in sequence, and stores energy in the inductor L2.

[0096] like Figure 7 As shown, due to the shunting effect of the inductor, the current IL1 of the inductor L1 and the current IL2 of the inductor L2 are both small, so the ripple itself is small; and the output current Io represents the inductor current of all inductors, that is, Io is the sum of the two inductor currents. Since the charging and discharging processes of the two inductors can be partially offset, the ripple of the overall inductor current (output current Io) can be reduced.

[0097] Step A2: When the DC converter discharges from the first access terminal to the second access terminal and the voltage of the first access terminal is lower than the voltage of the second access terminal, the fourth switch tube is used as the main switch tube. At this time, the third switch tube is the auxiliary switch tube, the first switch tube is the normally open upper switch tube, and the second switch tube is the normally closed lower switch tube.

[0098] Optionally, the above step of “determining the main duty cycle of the main switch tube” includes the following step B2.

[0099] Step B2: When the main switch is the fourth switch, the main duty cycle of the main switch is: At this time, the DC conversion unit is a positive boost circuit.

[0100] like Figure 3 As shown, if the power supply voltage of the first battery Bat1 is lower than the power supply voltage of the second battery Bat2, and the first battery Bat1 needs to discharge the power supply of the second battery Bat2, the fourth switch tube is used as the main switch tube. That is, the switch tubes Q7 and Q8 are the main switch tubes of the corresponding DC conversion unit. At this time, the working principle diagram of the DC converter can be seen in Figure 8 As shown in the figure (the upper part corresponds to the inductor charging, and the lower part corresponds to the inductor discharging), and the timing diagram of the control signal of each switch tube can be found in Fig. 9 As shown. Fig. 9 As shown, the first switch tubes Q1 and Q2 remain turned on, the second switch tubes Q3 and Q4 remain turned off, the timing between the fourth switch tubes Q7 and Q8 always maintains a phase difference of 180 degrees, and the timing between the third switch tubes Q5 and Q6 also always maintains a phase difference of 180 degrees.

[0101] like Figure 8 As shown, when the fourth switch tube Q7 is turned off, the third switch tube Q5 is turned on, which serves as a freewheeling switch tube for releasing the energy stored in the inductor L1. There is a dead time between the turning on of the third switch tube Q5 and the turning off of the fourth switch tube Q7, so as to avoid the third switch tube Q5 and the fourth switch tube Q7 being turned on at the same time and causing a short circuit. For the DC conversion unit of another path, the third switch tube Q6 and the fourth switch tube Q8 are the same.

[0102] exist Fig. 9 In the timing diagram shown, at time T1, the fourth switch tube Q7 and the fourth switch tube Q8 are turned on, and the third switch tube Q5 and the third switch tube Q6 are turned off. At this time, the current of the two paths passes through the first battery Bat1 through the first switch tube Q1, the inductor L1, the fourth switch tube Q7 and the first switch tube Q2, the inductor L2, and the fourth switch tube Q8, and is stored in the inductor L1 and the inductor L2. At time T2, the fourth switch tube Q7 of one path is turned on, the third switch tube Q5 is turned off, the fourth switch tube Q8 of the second path is turned off, and the third switch tube Q6 is turned from open to closed and then open. At this time, the current of one path flows through the first switch tube Q1, the inductor L1, and the fourth switch tube Q7 in sequence, and stores energy in the inductor L1, and the current of the two paths flows through the first switch tube Q2, the inductor L2, and the third switch tube Q6 in sequence, and releases energy from the inductor L2 to the second battery Bat2.

[0103] At time T3, the fourth switch tube Q7 of one path is turned on, the third switch tube Q5 is turned off, the fourth switch tube Q8 of the second path is turned on, and the third switch tube Q6 is turned off, which is the same as time T1. At this time, the current of the two paths passes through the first battery Bat1 through the first switch tube Q1, the inductor L1, the fourth switch tube Q7 and the first switch tube Q2, the inductor L2, the fourth switch tube Q8, and is stored in the inductor L1 and the inductor L2. At time T4, the fourth switch tube Q7 of one path is turned off, and the third switch tube Q5 is turned off, the fourth switch tube Q8 of the second path is turned on, and the third switch tube Q6 is turned off. At this time, the current of one path flows through the first switch tube Q1, the inductor L1, and the third switch tube Q5 in sequence, releasing energy from the inductor L1 to the second battery Bat2, and the current of the two paths flows through the first switch tube Q2, the inductor L2, the fourth switch tube Q8 in sequence, and stores energy in the inductor L2.

[0104] Step A3, when the DC converter discharges from the second access terminal to the first access terminal and the voltage of the second access terminal is higher than the voltage of the first access terminal, the third switch tube is used as the main switch tube. At this time, the fourth switch tube is the auxiliary switch tube, the first switch tube is the normally open upper switch tube, and the second switch tube is the normally closed lower switch tube.

[0105] Optionally, the above step of “determining the main duty cycle of the main switch tube” includes the following step B3.

[0106] Step B3, when the main switch tube is the third switch tube, the main duty cycle of the main switch tube is: At this time, the DC conversion unit is a reverse step-down circuit.

[0107] like Figure 3 As shown, if the power supply voltage of the first battery Bat1 is lower than the power supply voltage of the second battery Bat2, and the second battery Bat2 needs to discharge the power supply of the first battery Bat1, then the third switch tube is used as the main switch tube in contrast to the above step A1. That is, the switch tubes Q5 and Q6 are the main switch tubes of the corresponding DC conversion unit. At this time, the working principle diagram of the DC converter can be seen in Fig.10 As shown in the figure (the upper part corresponds to the inductor charging, and the lower part corresponds to the inductor discharging), and the timing diagram of the control signal of each switch tube can be found in Fig.11 As shown. Fig.11 As shown, the first switch tubes Q1 and Q2 remain turned on, the second switch tubes Q3 and Q4 remain turned off, the timing between the third switch tubes Q5 and Q6 always maintains a phase difference of 180 degrees, and the timing between the fourth switch tubes Q7 and Q8 also always maintains a phase difference of 180 degrees.

[0108] like Fig.10As shown, when the third switch tube Q5 is turned off, the fourth switch tube Q7 is turned on, which serves as a freewheeling switch tube for releasing the energy stored in the inductor L1. There is a dead time between the turning on of the third switch tube Q5 and the turning off of the fourth switch tube Q7, so as to avoid the third switch tube Q5 and the fourth switch tube Q7 being turned on at the same time to cause a short circuit. For the DC conversion unit of another path, the third switch tube Q6 and the fourth switch tube Q8 are the same.

[0109] exist Fig.11 In the timing diagram shown, at time T1, the third switch tube Q5 and the third switch tube Q6 are turned on, and the fourth switch tube Q7 and the fourth switch tube Q8 are turned off. At this time, the currents of the two paths flow from the second battery Bat2 through the inductor L1 and the inductor L2 to the first battery Bat1, and are stored in the inductor L1 and the inductor L2. At time T2, the third switch tube Q5 of one path is turned on, the fourth switch tube Q7 is turned off, the third switch tube Q6 of the second path is turned off, and the fourth switch tube Q8 is turned from open to closed and then open. At this time, the current of one path flows through the third switch tube Q5, the inductor L1, and the first switch tube Q1 in sequence, and stores energy in the inductor L1. The current of the two paths flows through the fourth switch tube Q8, the inductor L2, and the first switch tube Q2 in sequence, and releases energy from the inductor L2 to the first battery Bat1.

[0110] At time T3, the third switch tube Q5 of one circuit is turned on, the fourth switch tube Q7 is turned off, the third switch tube Q6 of the second circuit is turned on, and the fourth switch tube Q8 is turned off, which is the same as time T1. At this time, the currents of the two circuits flow from the second battery Bat2 through the inductor L1 and the inductor L2 to the first battery Bat1, and are stored in the inductor L1 and the inductor L2. At time T4, the third switch tube Q5 of one circuit is turned off, and the fourth switch tube Q7 is turned off, closed, and then turned off. The third switch tube Q6 of the second circuit is turned on, and the fourth switch tube Q8 is turned off. At this time, the current of one circuit flows through the fourth switch tube Q7, the inductor L1, and the first switch tube Q1 in sequence, releasing energy from the inductor L1 to the first battery Bat1, and the current of the two circuits flows through the third switch tube Q6, the inductor L2, and the first switch tube Q2 in sequence, and stores energy in the inductor L2.

[0111] Step A4, when the DC converter discharges from the second access terminal to the first access terminal and the voltage of the second access terminal is lower than the voltage of the first access terminal, the second switch tube is used as the main switch tube. At this time, the first switch tube is the auxiliary switch tube, the third switch tube is the normally open upper switch tube, and the fourth switch tube is the normally closed lower switch tube.

[0112] Optionally, the above step of “determining the main duty cycle of the main switch tube” includes the following step B4.

[0113] Step B4, when the main switch tube is the second switch tube, the main duty cycle of the main switch tube is: At this time, the DC conversion unit is a reverse boost circuit.

[0114] like Figure 3 As shown, if the power supply voltage of the first battery Bat1 is higher than the power supply voltage of the second battery Bat2, and the second battery Bat2 needs to discharge the power supply of the first battery Bat1, then the second switch tube is used as the main switch tube in contrast to the above step A2. That is, the switch tubes Q3 and Q4 are the main switch tubes of the corresponding DC conversion unit. At this time, the working principle diagram of the DC converter can be seen in Fig.12 As shown in the figure (the upper part corresponds to the inductor charging, and the lower part corresponds to the inductor discharging), and the timing diagram of the control signal of each switch tube can be found in Fig.13 As shown. Fig.13 As shown, the third switch tubes Q5 and Q6 remain turned on, the fourth switch tubes Q7 and Q8 remain turned off, the timing between the first switch tubes Q1 and Q2 always maintains a phase difference of 180 degrees, and the timing between the second switch tubes Q3 and Q4 also always maintains a phase difference of 180 degrees.

[0115] like Fig.12 As shown, when the second switch tube Q3 is turned off, the first switch tube Q1 is turned on, and as a freewheeling switch tube for releasing the energy stored in the inductor L1, there is a dead time between the turn-on of the first switch tube Q1 and the turn-off of the second switch tube Q3, so as to avoid the short circuit caused by the simultaneous turn-on of the first switch tube Q1 and the second switch tube Q3. For the DC conversion unit of another circuit, the first switch tube Q2 and the second switch tube Q4 are the same.

[0116] exist Fig.13 In the timing diagram shown, at time T1, the second switch tube Q3 and the second switch tube Q4 are turned on, and the first switch tube Q1 and the first switch tube Q2 are turned off. At this time, the current of the two paths passes through the third switch tube Q5, the inductor L1, the second switch tube Q3 and the third switch tube Q6, the inductor L2, and the second switch tube Q4 from the second battery Bat2, and the energy is stored in the inductor L1 and the inductor L2. At time T2, the second switch tube Q3 of one path is turned on, the first switch tube Q1 is turned off, the second switch tube Q4 of the two paths is turned off, and the first switch tube Q2 changes from open to closed and then to open. At this time, the current of one path flows through the third switch tube Q5, the inductor L1, and the second switch tube Q3 in turn, and stores energy in the inductor L1. The current of the two paths flows through the third switch tube Q6, the inductor L2, and the first switch tube Q2 in turn, and releases energy from the inductor L2 to the first battery Bat1.

[0117] At time T3, the second switch tube Q3 of one path is turned on, the first switch tube Q1 is turned off, the second switch tube Q4 of the second path is turned on, and the first switch tube Q2 is turned off, which is the same as time T1. At this time, the currents of the two paths are from the second battery Bat2, the third switch tube Q5, the inductor L1, the second switch tube Q3 and the third switch tube Q6, the inductor L2, and the second switch tube Q4. The energy is stored in the inductor L1 and the inductor L2. At time T4, the second switch tube Q3 of one path is turned off, and the first switch tube Q1 is turned off, closed, and then turned off. The second switch tube Q4 of the second path is turned on, and the first switch tube Q2 is turned off. At this time, the current of one path flows through the third switch tube Q5, the inductor L1, and the first switch tube Q1 in turn, releasing energy from the inductor L1 to the first battery Bat1, and the current of the two paths flows through the third switch tube Q6, the inductor L2, the second switch tube Q4 in turn, and stores energy in the inductor L2.

[0118] It is understandable that the above Figure 7 , Fig. 9 , Fig.11 , Fig.13 Only the timing diagram of each control signal in one case is shown; for main duty cycles of other sizes, the working principle is similar to this and will not be repeated here.

[0119] Step S502, controlling the on and off of corresponding switch tubes according to the control signals of the switch tubes in the DC conversion unit.

[0120] For details, please see Figure 4 Step S402 of the illustrated embodiment will not be described in detail here.

[0121] The control method of the DC converter provided in this embodiment determines the preset phase difference based on the number of DC conversion units, and the control signal generated based on this can minimize the inductor ripple. The main switch tube is determined based on the actual situation, and the control signal of each main switch tube is generated according to the main duty cycle of the main switch tube. The control signal is generated in a simple way, and the DC converter can be controlled by a simple control method. And, if Figure 3 As shown, support capacitors C1 and C2 can be provided at both ends of the DC converter. Multiple inductors are used for current shunting, which reduces the heat dissipation requirements of the inductors, reduces the volume and weight of the inductors, and can also reduce the capacitance of the support capacitors C1 and C2, thereby reducing costs and improving the power density of the product.

[0122] In this embodiment, a control device for a DC converter is also provided, which is used to implement the above-mentioned embodiments and preferred implementation modes, and the descriptions that have been made are not repeated. As used below, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation of hardware, or a combination of software and hardware, is also possible and conceivable.

[0123] This embodiment provides a control device for a DC converter, wherein the DC converter comprises: a plurality of DC conversion units, wherein the DC conversion units comprise: a first switch tube, a second switch tube, a third switch tube, a fourth switch tube and an inductor, wherein the second end of the first switch tube is connected to the first end of the second switch tube and is connected to one end of the inductor; the second end of the third switch tube is connected to the first end of the fourth switch tube and is connected to the other end of the inductor;

[0124] The first switching tubes of each DC conversion unit share a first end and serve as the first access end of the DC converter; the third switching tubes of each DC conversion unit share a second end and serve as the second access end of the DC converter; the third switching tube and the fourth switching tube of each DC conversion unit share a second end.

[0125] like Fig.14 As shown, the device comprises:

[0126] The signal module 1401 is used to determine the control signal of each switch tube in the DC conversion unit; for different DC conversion units, the control signals of the same switch tube are provided with a preset phase difference;

[0127] The control module 1402 is used to control the on and off of the corresponding switch tube according to the control signal of each switch tube in the DC conversion unit.

[0128] In some optional implementations, the preset phase difference for:

[0129] Wherein, N is the number of the DC conversion units.

[0130] In some optional implementations, the signal module 1401 determines the control signal of each switch tube in the DC conversion unit, including:

[0131] Determine a main switch tube, and determine a main duty cycle of the main switch tube; the main switch tube is one of the first switch tube, the second switch tube, the third switch tube, and the fourth switch tube;

[0132] A main control signal of the DC conversion unit is generated according to the main duty cycle; a preset phase difference is set between the main control signals of different DC conversion units; and the main control signal of each DC conversion unit is used to control the on and off of the main switch tube of each DC conversion unit.

[0133] In some optional implementations, the signal module 1401 determines the control signal of each switch tube in the DC conversion unit, and further includes:

[0134] Determine a secondary switch tube; the secondary switch tube is another switch tube belonging to the same bridge arm as the main switch tube;

[0135] Generate a sub-control signal of the DC conversion unit; the sub-control signal of the DC conversion unit is complementary to the main control signal of the DC conversion unit, and there is a dead time; the sub-control signal of each DC conversion unit is used to control the on and off of the sub-switches of each DC conversion unit.

[0136] In some optional implementations, the signal module 1401 determines the control signal of each switch tube in the DC conversion unit, and further includes:

[0137] Setting the control signal of the upper switch tube belonging to a different bridge arm from the main switch tube to a normally open signal, and setting the control signal of the lower switch tube belonging to a different bridge arm from the main switch tube to a normally closed signal;

[0138] The upper switch tube is the first switch tube or the third switch tube, and the lower switch tube is the second switch tube or the fourth switch tube.

[0139] In some optional implementations, the signal module 1401 determines the main switch tube, including:

[0140] When the DC converter discharges from the first access terminal to the second access terminal and the voltage of the first access terminal is higher than the voltage of the second access terminal, the first switch tube is used as the main switch tube;

[0141] When the DC converter discharges from the first access terminal to the second access terminal and the voltage of the first access terminal is lower than the voltage of the second access terminal, the fourth switch tube is used as the main switch tube;

[0142] When the DC converter discharges from the second access terminal to the first access terminal and the voltage of the second access terminal is higher than the voltage of the first access terminal, the third switch tube is used as the main switch tube;

[0143] When the DC converter discharges from the second access terminal to the first access terminal and the voltage of the second access terminal is lower than the voltage of the first access terminal, the second switch tube is used as the main switch tube.

[0144] In some optional implementations, the signal module 1401 determines the main duty cycle of the main switch tube, including:

[0145] When the main switch tube is the first switch tube, the main duty cycle of the main switch tube is: When the main switch tube is the fourth switch tube, the main duty cycle of the main switch tube is: When the main switch tube is the third switch tube, the main duty cycle of the main switch tube is: When the main switch tube is the second switch tube, the main duty cycle of the main switch tube is: Wherein, D1 is the main duty cycle, V1 is the voltage of the first access terminal, and V2 is the voltage of the second access terminal.

[0146] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0147] The control device of the DC converter in this embodiment is presented in the form of a functional unit, where the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, including a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0148] The embodiment of the present invention also provides an electronic device having the above Fig.14 The control device of the DC converter shown. The electronic device may specifically be a controller of the DC converter.

[0149] See also Fig.15 , Fig.15 is a schematic diagram of the structure of an electronic device provided by an optional embodiment of the present invention, such as Fig.15 As shown, the electronic device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. The various components are connected to each other using different buses for communication, and can be installed on a common mainboard or installed in other ways as needed. The processor can process instructions executed in the electronic device, including instructions stored in or on the memory to display graphical information of the GUI on an external input / output device (such as a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories. Similarly, multiple electronic devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Fig.15 A processor 10 is taken as an example.

[0150] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0151] The memory 20 stores instructions executable by at least one processor 10, so that the at least one processor 10 executes the method shown in the above embodiment.

[0152] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the electronic device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the electronic device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0153] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 20 may also include a combination of the above types of memory.

[0154] The electronic device further comprises a communication interface 30 for the electronic device to communicate with other devices or a communication network.

[0155] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0156] A part of the present invention may be applied as a computer program product, such as a computer program instruction, which, when executed by a computer, can call or provide the method and / or technical solution according to the present invention through the operation of the computer. Those skilled in the art should understand that the existence of the computer program instruction in a computer-readable medium includes, but is not limited to, a source file, an executable file, an installation package file, etc., and accordingly, the way in which the computer program instruction is executed by the computer includes, but is not limited to: the computer directly executes the instruction, or the computer compiles the instruction and then executes the corresponding compiled program, or the computer reads and executes the instruction, or the computer reads and installs the instruction and then executes the corresponding installed program. Here, the computer-readable medium may be any available computer-readable storage medium or communication medium accessible to the computer.

[0157] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations should all be included in the protection scope of the present invention.

Claims

1. A control method for a DC converter, characterized in that: The DC converter includes: a plurality of DC conversion units, and the DC conversion units include: a first switch tube, a second switch tube, a third switch tube, a fourth switch tube and an inductor, and the second end of the first switch tube is connected to the first end of the second switch tube and connected to one end of the inductor; the second end of the third switch tube is connected to the first end of the fourth switch tube and connected to the other end of the inductor; The first switch tubes of each of the DC conversion units share a first end and serve as the first access end of the DC converter; the third switch tubes of each of the DC conversion units share a second end and serve as the second access end of the DC converter; the third switch tubes and the fourth switch tubes of each of the DC conversion units share a second end; The method comprises: Determine the control signal of each switch tube in the DC conversion unit; for different DC conversion units, a preset phase difference is set between the control signals of the same switch tube; According to the control signal of each switch tube in the DC conversion unit, the corresponding switch tube is controlled to be turned on and off.

2. The method according to claim 1, characterized in that The preset phase difference for: Wherein, N is the number of the DC conversion units.

3. The method according to claim 1, characterized in that: The step of determining the control signal of each switch tube in the DC conversion unit includes: Determine a main switch tube, and determine a main duty cycle of the main switch tube; the main switch tube is one of the first switch tube, the second switch tube, the third switch tube, and the fourth switch tube; A main control signal of the DC conversion unit is generated according to the main duty cycle; a preset phase difference is set between the main control signals of different DC conversion units; and the main control signal of each DC conversion unit is used to control the on and off of the main switch tube of each DC conversion unit.

4. The method according to claim 3, characterized in that The step of determining the control signal of each switch tube in the DC conversion unit further includes: Determine a secondary switch tube; the secondary switch tube is another switch tube belonging to the same bridge arm as the main switch tube; Generate a sub-control signal of the DC conversion unit; the sub-control signal of the DC conversion unit is complementary to the main control signal of the DC conversion unit, and there is a dead time; the sub-control signal of each DC conversion unit is used to control the on and off of the sub-switches of each DC conversion unit.

5. The method according to claim 3, characterized in that: The step of determining the control signal of each switch tube in the DC conversion unit further includes: Setting the control signal of the upper switch tube belonging to a different bridge arm from the main switch tube to a normally open signal, and setting the control signal of the lower switch tube belonging to a different bridge arm from the main switch tube to a normally closed signal; The upper switch tube is the first switch tube or the third switch tube, and the lower switch tube is the second switch tube or the fourth switch tube.

6. The method according to claim 3, characterized in that The determining of the main switch tube includes: When the DC converter discharges from the first access terminal to the second access terminal and the voltage of the first access terminal is higher than the voltage of the second access terminal, the first switch tube is used as the main switch tube; When the DC converter discharges from the first access terminal to the second access terminal and the voltage of the first access terminal is lower than the voltage of the second access terminal, the fourth switch tube is used as the main switch tube; When the DC converter discharges from the second access terminal to the first access terminal and the voltage of the second access terminal is higher than the voltage of the first access terminal, the third switch tube is used as the main switch tube; When the DC converter discharges from the second access terminal to the first access terminal and the voltage of the second access terminal is lower than the voltage of the first access terminal, the second switch tube is used as the main switch tube.

7. The method according to claim 6, characterized in that The determining of the main duty cycle of the main switch tube includes: When the main switch tube is the first switch tube, the main duty cycle of the main switch tube is: When the main switch tube is the fourth switch tube, the main duty cycle of the main switch tube is: When the main switch tube is the third switch tube, the main duty cycle of the main switch tube is: When the main switch tube is the second switch tube, the main duty cycle of the main switch tube is: Wherein, D1 is the main duty cycle, V1 is the voltage of the first access terminal, and V2 is the voltage of the second access terminal.

8. A control device for a DC converter, characterized in that: The DC converter includes: a plurality of DC conversion units, and the DC conversion units include: a first switch tube, a second switch tube, a third switch tube, a fourth switch tube and an inductor, and the second end of the first switch tube is connected to the first end of the second switch tube and connected to one end of the inductor; the second end of the third switch tube is connected to the first end of the fourth switch tube and connected to the other end of the inductor; The first switch tubes of each of the DC conversion units share a first end and serve as the first access end of the DC converter; the third switch tubes of each of the DC conversion units share a second end and serve as the second access end of the DC converter; the third switch tubes and the fourth switch tubes of each of the DC conversion units share a second end; The device comprises: A signal module, used to determine the control signal of each switch tube in the DC conversion unit; for different DC conversion units, a preset phase difference is set between the control signals of the same switch tube; The control module is used to control the on and off of the corresponding switch tube according to the control signal of each switch tube in the DC conversion unit.

9. An electronic device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the control method of the DC converter according to any one of claims 1 to 7 by executing the computer instructions.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the control method of the DC converter according to any one of claims 1 to 7.

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