Control methods, DC / DC conversion circuits and energy storage devices

Abstract

This application discloses a control method, a DC / DC converter circuit, and an energy storage device, belonging to the field of electronic technology. The method includes: when a jump in the input voltage on the input side is detected, from a first voltage to a second voltage, if the first voltage is greater than the target output voltage and the second voltage is less than the target output voltage, then increasing the first duty cycle of the first upper bridge arm to a first preset value at a first preset rate of change. After the first duty cycle increases to the first preset value, controlling the first duty cycle to decrease from the first preset value to a second preset value and maintain it at the second preset value, and controlling the second duty cycle of the second lower bridge arm to increase at a second preset rate of change, until the actual output voltage of the DC / DC converter circuit is the same as the target output voltage. In this way, not only can the current of the energy storage inductor be well controlled, avoiding triggering overcurrent protection, but the stability of the actual output voltage on the output side can also be ensured when the input voltage on the input side jumps.

Description

Technical Field

[0001] This application relates to the field of electronic technology, and in particular to a control method for a DC / DC (Direct Current / Direct Current) converter circuit, a DC / DC converter circuit, and an energy storage device. Background Technology

[0002] With the continuous development of new energy technologies, photovoltaic power generation technology is becoming increasingly popular. Photovoltaic power generation technology converts solar energy into electrical energy, which is then used to charge a battery pack via a DC / DC converter circuit. The input terminal of the DC / DC converter circuit is connected to the photovoltaic panel to receive its input voltage; the output terminal is connected to the battery pack to charge it. The DC / DC converter circuit may include inductors, capacitors, and switching transistors.

[0003] During the charging process of a photovoltaic panel and a battery pack via a DC / DC converter circuit, the input voltage of the photovoltaic panel may change, which can affect the charging stability of the battery pack. To address this, related technologies can control the DC / DC converter circuit to switch from buck mode to boost mode when the input voltage drops, causing the actual output voltage to be lower than the expected output voltage. In boost mode, the actual output voltage is increased by increasing the duty cycle of the corresponding switching transistor, thus maintaining the stability of the actual output voltage of the DC / DC converter circuit.

[0004] However, in boost mode, the increased duty cycle of the switching transistor causes the inductor current to increase rapidly, which in turn causes the inductor current to quickly reach the OCP (Over Current Protection) point, thus triggering the system to perform overcurrent protection. Summary of the Invention

[0005] This application provides a control method for a DC / DC converter circuit, a DC / DC converter circuit, and an energy storage device, which can ensure the stability of the output voltage while avoiding triggering OCP. The technical solution is as follows:

[0006] Firstly, a control method for a DC / DC converter circuit is provided, the method comprising:

[0007] When the input voltage on the input side is detected to jump from the first voltage to the second voltage, if the first voltage is greater than the target output voltage of the DC / DC converter circuit and the second voltage is less than the target output voltage, the first duty cycle of the first upper bridge arm is gradually increased to a first preset value.

[0008] After the first duty cycle increases to the first preset value, the first duty cycle is controlled to decrease from the first preset value to the second preset value and remain at the second preset value, and the second duty cycle of the second lower bridge arm is controlled to gradually increase until the actual output voltage of the DC / DC conversion circuit is the same as the target output voltage.

[0009] In this application, when the input voltage on the input side is detected to jump from a first voltage to a second voltage, if the first voltage is greater than the target output voltage of the DC / DC converter circuit and the second voltage is less than the target output voltage, the first duty cycle of the first upper bridge arm is gradually increased to a first preset value. This allows the first duty cycle of the first upper bridge arm to gradually increase, so that the output voltage on the output side, after decreasing, can gradually increase back to the second voltage. After the first duty cycle increases to the first preset value, the first duty cycle is controlled to decrease from the first preset value to a second preset value and maintained at the second preset value, while the second duty cycle of the second lower bridge arm is controlled to gradually increase until the actual output voltage of the DC / DC converter circuit is the same as the target output voltage.

[0010] In other words, in the scheme of this application, after the first duty cycle increases to a first preset value, it decreases to a second preset value and remains at the second preset value. This allows the DC / DC converter circuit to operate in buck-boost mode instead of boost mode, which reduces the overall rise rate of the energy storage inductor current and increases the overall fall rate of the energy storage inductor current. Therefore, the current of the energy storage inductor can be well controlled, avoiding triggering OCP. Furthermore, since the second duty cycle of the second lower bridge arm gradually increases until the actual output voltage on the output side is the same as the target output voltage, the stability of the actual output voltage on the output side can be guaranteed even if the input voltage on the input side changes abruptly.

[0011] In some possible implementations, gradually increasing the first duty cycle of the first upper bridge arm to a first preset value includes:

[0012] The first duty cycle of the first upper bridge arm is increased to a first preset value by a first preset rate of change.

[0013] The step of gradually increasing the second duty cycle of the second lower bridge arm until the actual output voltage of the DC / DC converter circuit is the same as the target output voltage includes:

[0014] The second duty cycle of the second lower bridge arm is controlled to increase at a second preset rate of change until the actual output voltage of the DC / DC converter circuit is the same as the target output voltage.

[0015] In some possible implementations, before increasing the first duty cycle of the first upper bridge arm to a first preset value by a first preset rate of change, the method further includes:

[0016] When the input voltage is detected to jump from the first voltage to the second voltage, the ratio between the target output voltage and the first voltage is determined as the first starting value of the first duty cycle;

[0017] The step of increasing the first duty cycle of the first upper bridge arm to a first preset value by a first preset rate of change includes:

[0018] The first duty cycle of the first upper bridge arm is increased from the first initial value to the first preset value at the first preset rate of change.

[0019] In some possible implementations, the second duty cycle of the second lower bridge arm is increased at a second preset rate of change until the actual output voltage of the DC / DC converter circuit is the same as the target output voltage, including:

[0020] The second duty cycle of the second lower bridge arm is controlled to start from a preset second initial value and increase at the second preset rate of change until the actual output voltage is the same as the target output voltage.

[0021] In some possible implementations, the method further includes:

[0022] If the first voltage is greater than the target output voltage and the second voltage is equal to the target output voltage, then the first duty cycle is increased to the first preset value by the first preset rate of change.

[0023] After the first duty cycle increases to the first preset value, the first duty cycle is controlled to decrease from the first preset value to the second preset value, and the second duty cycle is controlled to increase to the preset second starting value; the sum of the second preset value and the second starting value is 100%.

[0024] In some possible implementations, the method further includes:

[0025] If the first voltage is less than the target output voltage and the second voltage is greater than the target output voltage, then the first duty cycle is controlled to remain at the second preset value, and the second duty cycle is reduced to a preset second starting value at a third preset rate of change.

[0026] After the second duty cycle decreases to the second initial value, the driving of the second lower bridge arm is stopped, and the first duty cycle is controlled to decrease at a fourth preset rate of change until the actual output voltage is the same as the target output voltage.

[0027] In some possible implementations, the method further includes:

[0028] If the first voltage is less than the target output voltage and the second voltage is equal to the target output voltage, then the first duty cycle is controlled to remain at the second preset value, and the second duty cycle is reduced to a preset second starting value at a third preset rate of change; the sum of the second preset value and the second starting value is 100%.

[0029] In some possible implementations, the method further includes:

[0030] If both the first voltage and the second voltage are greater than the target output voltage, then the ratio between the target output voltage and the second voltage is determined as the first target value of the first duty cycle;

[0031] The first duty cycle is controlled to be adjusted to the first target value by the fifth preset rate of change.

[0032] In some possible implementations, the method further includes:

[0033] If both the first voltage and the second voltage are less than the target output voltage, then a second target value for the second duty cycle is determined based on the first duty cycle, the second voltage, and the target output voltage.

[0034] The second duty cycle is controlled to be adjusted to the second target value at a sixth preset rate of change.

[0035] In a second aspect, a DC / DC converter circuit is provided, comprising a first bridge arm unit connected to the input side, a second bridge arm unit connected to the output side, an energy storage inductor, and a controller; the energy storage inductor is connected at the midpoint between the first bridge arm unit and the second bridge arm unit; the first bridge arm unit comprises a first upper bridge arm and a first lower bridge arm connected in series; the second bridge arm unit comprises a second upper bridge arm and a second lower bridge arm connected in series; both the first upper bridge arm and the second lower bridge arm include a controllable switching transistor; the controller is used to execute the control method of the DC / DC converter circuit described in the first aspect.

[0036] Thirdly, a control device for a DC / DC converter circuit is provided, the device comprising:

[0037] The first amplification module is used to increase the first duty cycle of the first upper bridge arm to a first preset value by a first preset rate of change when it detects that the input voltage on the input side has changed from a first voltage to a second voltage, if the first voltage is greater than the target output voltage of the DC / DC conversion circuit and the second voltage is less than the target output voltage.

[0038] The first control module is configured to, after the first duty cycle increases to the first preset value, control the first duty cycle to decrease from the first preset value to the second preset value and maintain it at the second preset value, and control the second duty cycle of the second lower bridge arm to increase at the second preset rate of change until the actual output voltage of the DC / DC conversion circuit is the same as the target output voltage.

[0039] Fourthly, an energy storage device is provided, the energy storage device including a battery pack and the aforementioned DC / DC conversion circuit, the output side of the DC / DC conversion circuit being connected to the battery pack to charge the battery pack.

[0040] Fifthly, a computer-readable storage medium is provided, the computer-readable storage medium storing a computer program, which, when executed by a processor, implements the control method for the DC / DC conversion circuit described in the first aspect.

[0041] In a sixth aspect, a computer program product containing instructions is provided, which, when run on a computer, causes the computer to perform the steps of the control method for the DC / DC converter circuit described in the first aspect.

[0042] It is understood that the beneficial effects of the second, third, fourth, fifth, and sixth aspects mentioned above can be found in the relevant descriptions in the first aspect above, and will not be repeated here. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This is a schematic diagram of a power supply system provided in an embodiment of this application;

[0045] Figure 2 This is a schematic diagram of a DC / DC conversion circuit provided in an embodiment of this application;

[0046] Figure 3 This is a schematic diagram of another DC / DC conversion circuit provided in an embodiment of this application;

[0047] Figure 4 This is a flowchart of a control method for a DC / DC converter circuit provided in an embodiment of this application;

[0048] Figure 5This is a schematic diagram of the control process of a DC / DC converter circuit provided in an embodiment of this application;

[0049] Figure 6 This is a schematic diagram of the control process of another DC / DC converter circuit provided in an embodiment of this application;

[0050] Figure 7 This is a schematic diagram of the control process of another DC / DC converter circuit provided in an embodiment of this application;

[0051] Figure 8 This is a schematic diagram of the control process of another DC / DC converter circuit provided in an embodiment of this application;

[0052] Figure 9 This is a schematic diagram of the control process of another DC / DC converter circuit provided in an embodiment of this application;

[0053] Figure 10 This is a schematic diagram of the control process of another DC / DC converter circuit provided in an embodiment of this application;

[0054] Figure 11 This is a schematic diagram of the structure of a control device for a DC / DC converter circuit provided in an embodiment of this application. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0056] It should be understood that "multiple" as mentioned in this application refers to two or more. In the description of this application, unless otherwise stated, " / " indicates "or," for example, A / B can mean A or B; "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist, for example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, to facilitate a clear description of the technical solutions of this application, the terms "first," "second," etc., are used to distinguish identical or similar items with essentially the same function and effect. Those skilled in the art will understand that the terms "first," "second," etc., do not limit the quantity or execution order, and that "first," "second," etc., do not necessarily imply differences.

[0057] The terms "one embodiment" or "some embodiments" used in this application mean that one or more embodiments of this application include the specific features, structures, or characteristics described in that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this application do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. Furthermore, the terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0058] Before providing a detailed explanation of the embodiments of this application, the application scenarios of these embodiments will be described first.

[0059] DC / DC converter circuits can be applied to photovoltaic power generation systems. A DC / DC converter circuit includes a first bridge arm unit connected to the input side, a second bridge arm unit connected to the output side, and an energy storage inductor connected at the midpoint between the first and second bridge arm units. For example, the input terminal of the DC / DC converter circuit can be connected to a photovoltaic power generation device, and the output terminal can be connected to a battery pack. The photovoltaic power generation device converts light energy into electrical energy, which is input to the DC / DC converter circuit. After being boosted or bucked by the DC / DC converter circuit, the electrical energy is used to charge the battery pack. However, the input voltage of the photovoltaic power generation device will change due to the influence of sunlight intensity. For example, when the sun changes from unobstructed to shaded, the sunlight intensity decreases, and the input voltage of the photovoltaic power generation device will change from a higher voltage to a lower voltage, resulting in a drop in the actual output voltage. This will affect the stability of the battery pack's charging voltage.

[0060] To address this, this application provides a control method for a DC / DC converter circuit. When the input voltage on the input side changes from a higher voltage to a lower voltage, the duty cycle of the first upper bridge arm is gradually increased to a first preset value. After the duty cycle of the first upper bridge arm increases to the first preset value, the duty cycle of the first upper bridge arm is controlled to decrease from the first preset value to a second preset value and maintained at the second preset value. Meanwhile, the duty cycle of the second lower bridge arm is controlled to gradually increase until the actual output voltage on the output side is the same as the target output voltage.

[0061] In other words, in the scheme of this application, the first duty cycle is reduced to and maintained at the second preset value, thereby making the DC / DC conversion circuit work in buck-boost mode instead of boost mode. This reduces the overall rise rate of the energy storage inductor current and increases the overall fall rate of the energy storage inductor current, thus effectively controlling the energy storage inductor current and avoiding triggering OCP. Furthermore, since the duty cycle of the second lower bridge arm gradually increases until the actual output voltage on the output side is the same as the target output voltage, the stability of the actual output voltage on the output side can be guaranteed even if the input voltage on the input side changes abruptly.

[0062] Figure 1 This is a schematic diagram of a power supply system provided in an embodiment of this application. See also... Figure 1 The power supply system may include a DC power supply device 101, a DC / DC conversion circuit 102, and an energy storage device 103.

[0063] The DC power supply device 101 is used to provide electrical energy to the energy storage device 103. In some embodiments, the DC power supply device 101 may be a photovoltaic power generation device, a wind power generation device, or other power supply device that can provide DC power, and this application embodiment does not limit this.

[0064] DC / DC converter circuit 102 is used to boost or buck the input DC power before outputting it.

[0065] The energy storage device 103 is used to store electrical energy. In some embodiments, the energy storage device 103 may be a battery pack or the like, but this application embodiment does not limit this.

[0066] In some cases, the DC / DC converter circuit 102 may be a part of the circuitry constituting the energy storage device 103; or, as... Figure 1 As shown, the DC / DC conversion circuit 102 can also be a separate circuit independent of the energy storage device 103, and this application embodiment does not limit this.

[0067] For example, energy storage device 103 may include a battery pack ( Figure 1 (Not shown) and DC / DC converter circuit 102. In this case, the output side of DC / DC converter circuit 102 can be connected to the battery pack to charge the battery pack; and / or, the output side of DC / DC converter circuit 102 can also supply power to other loads connected to energy storage device 103 through energy storage device 103.

[0068] In this configuration, the DC power supply device 101 is connected to the input terminal IN of the DC / DC converter circuit 102, and the output terminal OUT of the DC / DC converter circuit 102 is connected to the energy storage device 103. Thus, the DC power supply device 101 can supply power to the energy storage device 103 through the DC / DC converter circuit 102.

[0069] It should be understood that the above power supply system is merely an illustrative example of this application, and the control method and DC / DC conversion circuit provided in this application can also be applied to other applicable power supply systems. For example, in some other power supply systems, the above-mentioned energy storage device 103 can be replaced by a load, such as household electrical appliances, etc. This application does not limit the objects included in the applicable power supply system or the connection relationships between the objects.

[0070] Figure 2 This is a schematic diagram of a DC / DC converter circuit 102 provided in an embodiment of this application. See also... Figure 2 The DC / DC converter circuit 102 includes an input terminal IN, a first bridge arm unit 201, an energy storage inductor 202, a second bridge arm unit 203, and an output terminal OUT.

[0071] The input terminal IN is used to connect to the input-side device (i.e., the DC power supply device 101 mentioned above), and the output terminal OUT is used to connect to the output-side device (e.g., ...). Figure 1 The energy storage device 103 shown is connected.

[0072] The first bridge arm unit 201 is connected to the input terminal IN, and the second bridge arm unit 203 is connected to the output terminal OUT. The energy storage inductor 202 is connected between the midpoint Z1 of the first bridge arm unit 201 and the midpoint Z2 of the second bridge arm unit 203.

[0073] The first bridge arm unit 201 includes a first upper bridge arm Q1 and a first lower bridge arm D1 connected in series. In this case, the first upper bridge arm Q1 and the first lower bridge arm D1 are located at the midpoint Z1 of the first bridge arm unit 201 described above.

[0074] The second bridge arm unit 203 includes a second upper bridge arm D2 and a second lower bridge arm Q2 connected in series. In this case, the second upper bridge arm D2 and the second lower bridge arm Q2 are located at the midpoint Z2 of the second bridge arm unit 203 described above.

[0075] The positive terminal of input IN is connected to the first upper bridge arm Q1, and the negative terminal of input IN is connected to the first lower bridge arm D1. The positive terminal of output OUT is connected to the second upper bridge arm D2, and the negative terminal of output OUT is connected to the second lower bridge arm Q2. The negative terminal of input IN is connected to the negative terminal of output OUT.

[0076] Both the first upper bridge arm Q1 and the second lower bridge arm Q2 may include controllable switching transistors. In some embodiments, such as Figure 3 As shown, both the first upper bridge arm Q1 and the second lower bridge arm Q2 can be composed of a body diode and a controllable switching transistor connected in parallel; alternatively, the first upper bridge arm Q1 and / or the second lower bridge arm Q2 can also be composed solely of controllable switching transistors. The type of controllable switching transistor used in the first upper bridge arm Q1 and the second lower bridge arm Q2 can be a metal-oxide-semiconductor (MOS) transistor, an insulated-gate bipolar transistor (IGBT), a bipolar transistor, etc., and this embodiment does not limit the specific type of transistor used.

[0077] In some embodiments, such as Figure 3 As shown, both the first lower bridge arm D1 and the second upper bridge arm D2 can be diodes; in other embodiments, the first lower bridge arm D1 and / or the second upper bridge arm D2 can also be switching transistors (including but not limited to MOSFETs, IGBTs, transistors, etc.), and this application does not limit this.

[0078] It should be noted that if the first lower bridge arm D1 is a switching transistor, then when the first upper bridge arm Q1 is turned on, the first lower bridge arm D1 remains in a normally open state; when the first upper bridge arm Q1 is turned off, the first lower bridge arm D1 remains in a normally closed state. If the second upper bridge arm D2 is a switching transistor, then when the second lower bridge arm Q2 is turned on, the second upper bridge arm D2 remains in a normally open state; when the second lower bridge arm Q2 is turned off, the second upper bridge arm D2 remains in a normally closed state.

[0079] The first upper arm Q1 and the second lower arm Q2 have a control cycle, the duration of which is the sum of the on-time and off-time. The first upper arm Q1 and the second lower arm Q2 also have a duty cycle, which is the ratio of the on-time to the total on-time within the control cycle. A larger duty cycle results in a longer on-time within the control cycle; a smaller duty cycle results in a shorter on-time within the control cycle.

[0080] For example, the operation of the DC / DC converter circuit 102 can be achieved by MPPT (Maximum Power Point Tracking) technology. Of course, the operation of the DC / DC converter circuit 102 can also be achieved by other technologies, and this application embodiment does not limit this.

[0081] The operation of the DC / DC converter circuit 102 can include the following three scenarios:

[0082] In the first scenario: when both the first upper bridge arm Q1 and the second lower bridge arm Q2 are in the on state, the current flows from the positive terminal of the input IN into the DC / DC converter circuit 102, then through the first upper bridge arm Q1, the energy storage inductor 202, and the second lower bridge arm Q2, finally returning to the negative terminal of the input IN. In this way, the energy storage inductor 202 is charged, and the amount of energy stored in the energy storage inductor 202 increases.

[0083] In the second scenario: when the first upper bridge arm Q1 is in the on state and the second lower bridge arm Q2 is in the off state, the current flows from the positive terminal IN into the DC / DC converter circuit 102, and then through the first upper bridge arm Q1, the energy storage inductor 202, and the second upper bridge arm D2 to the positive terminal OUT to supply power to the devices connected to the output side.

[0084] The third scenario: When both the first upper bridge arm Q1 and the second lower bridge arm Q2 are in the off state, the energy storage inductor 202 discharges. At this time, the current flows out from the energy storage inductor 202, through the second upper bridge arm D1, to the positive terminal of the output terminal OUT, so as to supply power to the equipment connected to the output side.

[0085] As can be seen from the above three scenarios, in the DC / DC converter circuit 102, when there is an input voltage at the input terminal IN, the duty cycle of the first upper bridge arm Q1 and the duty cycle of the second lower bridge arm Q2 will affect the output voltage at the output terminal OUT. Therefore, when the input voltage at the input terminal IN changes, the stability of the output voltage at the output terminal OUT can be maintained by adjusting the duty cycle of the first upper bridge arm Q1 and the duty cycle of the second lower bridge arm Q2.

[0086] In some embodiments, such as Figure 3 As shown, the DC / DC converter circuit 102 may also include a capacitor C and a switch K.

[0087] In some embodiments, when the OCP is triggered due to excessive current in the energy storage inductor 202, the switch K can be controlled to open to protect the DC / DC converter circuit 102. For example, the switch K can be a relay, etc., but this embodiment does not limit the application to this.

[0088] It should be noted that in related technologies, when the input voltage at the input terminal IN drops and falls below the output voltage, the duty cycle of the first upper bridge arm Q1 can be increased to 100% to control the DC / DC converter circuit to switch from buck mode to boost mode. In boost mode, the duty cycle of the second lower bridge arm Q2 is increased to maintain the stability of the output voltage at the output terminal OUT. However, during the increase of the duty cycle of the second lower bridge arm Q2, the current of the energy storage inductor 202 will increase rapidly, causing the current of the energy storage inductor 202 to quickly reach the OCP point. This will trigger the system to perform OCP, controlling the switch K to open. After the switch K is open for a period of time (e.g., 10 seconds), the switch K will close again. Because the voltage of capacitor C is relatively large before the switch K is open, while the voltage at the input terminal IN is relatively small, the voltage difference across the switch K is large, which can cause arcing, leading to the contacts of the switch K sticking together and causing safety issues.

[0089] Therefore, embodiments of this application provide the following when the input voltage at input terminal IN changes: Figure 4 The method described in this embodiment aims to maintain a stable output voltage at the output terminal OUT while avoiding triggering OCP, thereby preventing related safety issues.

[0090] In some embodiments, the DC / DC converter circuit 102 may further include a controller that can perform the following... Figure 4 The method described in the examples.

[0091] The control method of the DC / DC converter circuit provided in the embodiments of this application will be explained in detail below.

[0092] Figure 4 This is a flowchart illustrating a control method for a DC / DC converter circuit according to an embodiment of this application. This method can be applied to a DC / DC converter circuit, specifically to a controller within that circuit. For example, the DC / DC converter circuit can be as described above... Figures 1 to 3 The DC / DC converter circuit 102 described in the embodiment. See also... Figure 4 The method includes the following steps:

[0093] Step 401: When the controller detects that the input voltage on the input side changes from the first voltage to the second voltage, if the first voltage is greater than the target output voltage of the DC / DC converter circuit and the second voltage is less than the target output voltage, the controller will gradually increase the first duty cycle of the first upper bridge arm to the first preset value.

[0094] The target output voltage is the voltage required by the device on the output side of the DC / DC converter circuit. For example, if a load is connected to the output side of the DC / DC converter circuit, the target output voltage is the voltage required for the load to operate. Or, for example, if a battery pack is connected to the output side of the DC / DC converter circuit, the target output voltage is the charging voltage required by the battery pack.

[0095] In some embodiments, the controller determines that the input voltage on the input side has changed by: if the controller detects that the change in the input voltage on the input side within a preset time period is greater than a preset voltage change range, then the controller determines that the input voltage on the input side has changed.

[0096] The first duty cycle is the duty cycle of the first upper arm. The rate of change of the first duty cycle is the change in the first duty cycle per unit time.

[0097] In some embodiments, the controller can increase the first duty cycle of the first upper bridge arm to a first preset value at a first preset rate of change.

[0098] The first preset rate of change can be preset. The first preset rate of change is greater than 0. For example, the first preset rate of change can be a single preset rate, such as a change of 1.8%, 1.9%, or 2.0% per unit time. Alternatively, the first preset rate of change can include multiple preset rates of change, such as at least two of 1.8%, 1.9%, or 2.0% per unit time. The duration of the aforementioned unit time can be determined according to actual needs.

[0099] When the first preset rate of change is a preset rate of change, the controller increases the first duty cycle of the first upper bridge arm to the first preset value at this preset rate of change. That is, the rate of change of the first duty cycle is the same during the increase process.

[0100] For example, the first preset value is 100%, and the first preset change rate is 1.9% per unit time. The controller can continuously increase the first duty cycle of the first upper bridge arm to 100% at a change rate of 1.9% per unit time.

[0101] When the first preset rate of change includes multiple preset rates of change, the controller can sequentially increase the first duty cycle of the first upper bridge arm by the multiple preset rates of change until the first duty cycle of the first upper bridge arm is increased to the first preset value.

[0102] For example, the first preset value is 100%, and the first preset change rate includes a change of 1.9% every unit time and a change of 2.0% every unit time. The controller can first increase the first duty cycle of the first upper bridge arm to 70% at a change rate of 1.9% every unit time, and then continue to increase the first duty cycle of the first upper bridge arm to 100% at a change rate of 2.0% every unit time.

[0103] It should be noted that among the multiple preset change rates included in the first preset change rate, the previously used preset change rate can be smaller than the later used preset change rate. That is, the multiple preset change rates can increase sequentially, and the change rate can be gradually increased. In this way, the controller can increase the first duty cycle of the first upper bridge arm to the first preset value in a relatively short time.

[0104] The first preset value can be set in advance. The first preset value can be set to a relatively large value. For example, the first preset value can be set to 98%, 99%, 100%, etc., but this application embodiment does not limit this.

[0105] It should be noted that if the input voltage on the input side is greater than the target output voltage, it indicates that the input voltage on the input side is high. In this case, the DC / DC converter circuit can operate in buck mode, with the duty cycle of the first upper bridge arm greater than 0% and less than the first preset value, and the duty cycle of the second lower bridge arm 0%, meaning the second lower bridge arm is in the off state. At this time, the input voltage on the input side is stepped down to the target output voltage by the first upper bridge arm, the energy storage inductor, and the second upper bridge arm, and then output to the device on the output side to power the device.

[0106] If the input voltage before the input transition (i.e., the first voltage) is greater than the target output voltage, and the input voltage after the input transition (i.e., the second voltage) is less than the target output voltage, it indicates that the input voltage on the input side has decreased, and the actual output voltage on the output side will also decrease accordingly. In this case, while maintaining the duty cycle of the second lower bridge arm at 0%, the controller increases the first duty cycle of the first upper bridge arm to a first preset value at a first preset rate of change. In this way, the first duty cycle of the first upper bridge arm can be gradually increased, avoiding the problem of sudden changes in duty cycle. Thus, the actual output voltage on the output side, after decreasing due to the input voltage transition, can gradually increase back to the target output voltage.

[0107] In some embodiments, when the controller detects that the input voltage on the input side has switched from a first voltage to a second voltage, it can also determine a first initial value for the first duty cycle. Then, the controller can increase the first duty cycle of the first upper bridge arm from the first initial value to a first preset value at a first preset rate of change.

[0108] The first initial value of the first duty cycle is the duty cycle of the first upper bridge arm when the input voltage on the input side is the first voltage.

[0109] In one possible implementation, the controller determines the first initial value of the first duty cycle by: determining the ratio between the target output voltage and a first voltage as the first initial value of the first duty cycle. For example, the controller can determine the first initial value of the first duty cycle using the following formula:

[0110]

[0111] Where D1 is the first initial value of the first duty cycle, V out1 For the target output voltage, V in1 This is the first voltage.

[0112] Step 402: After the first duty cycle increases to the first preset value, the controller controls the first duty cycle to decrease from the first preset value to the second preset value and maintain it at the second preset value, and controls the second duty cycle of the second lower bridge arm to gradually increase until the actual output voltage of the DC / DC conversion circuit is the same as the target output voltage.

[0113] The second preset value can be set in advance. The second preset value can be set to a larger value, which is smaller than the first preset value. For example, the second preset value can be set to 89%, 90%, 91%, etc., but this application embodiment does not limit this.

[0114] The second duty cycle is the duty cycle of the second lower bridge arm. The rate of change of the second duty cycle is the amount of change of the second duty cycle per unit time.

[0115] In some embodiments, the controller may control the second duty cycle of the second lower bridge arm to increase at a second preset rate of change until the actual output voltage of the DC / DC converter circuit is the same as the target output voltage.

[0116] The second preset rate of change can be set in advance. The second preset rate of change is greater than 0. For example, the second preset rate of change can be an increase of 1.8%, 1.9%, 2.0%, etc., every unit of time.

[0117] On one hand, after the first duty cycle increases to a first preset value, the controller controls the first duty cycle to decrease from the first preset value to a second preset value and maintain it at the second preset value. Thus, the first upper bridge arm will have a turn-off phase during the control cycle, during which the energy storage inductor will discharge. On the other hand, after the first duty cycle increases to the first preset value, the controller increases the second duty cycle of the second lower bridge arm by a second preset rate of change, which can avoid the problem of sudden duty cycle changes. Thus, the conduction time of the second lower bridge arm gradually increases during the control cycle. During the conduction phase of the second lower bridge arm, the energy storage inductor will charge, and during the turn-off phase, the energy storage inductor will discharge. Furthermore, the second duty cycle of the second lower bridge arm will gradually increase until the actual output voltage on the output side is the same as the target output voltage, thus ensuring the stability of the actual output voltage on the output side even if the input voltage on the input side changes abruptly.

[0118] As can be seen above, when both the first upper bridge arm and the second lower bridge arm are in the ON phase, the input-side device charges the energy storage inductor. When the first upper bridge arm is in the ON phase and the second lower bridge arm is in the OFF phase, both the input-side device and the energy storage inductor charge the output-side device. When both the first upper bridge arm and the second lower bridge arm are in the OFF phase, only the energy storage inductor charges the output-side device. Therefore, compared to the boost mode, in the buck-boost mode, the overall rate of increase of the energy storage inductor current is smaller, and the overall rate of decrease of the energy storage inductor current is larger. This allows for better control of the energy storage inductor current, preventing OCP (Optical Current Collapse) and thus avoiding other problems caused by OCP, such as switch contact sticking caused by repeated switching due to OCP.

[0119] In some embodiments, the operation of the controller controlling the second duty cycle of the second lower bridge arm to increase at a second preset rate of change until the actual output voltage of the DC / DC converter circuit is the same as the target output voltage can be: the controller controls the second duty cycle of the second lower bridge arm to start from a preset second initial value and increase at a second preset rate of change until the actual output voltage on the output side is the same as the target output voltage.

[0120] The second starting value can be preset. The second starting value can be set relatively small. On the one hand, the second starting value cannot be set too small, otherwise it may cause the second lower bridge arm to not be fully conductive. On the other hand, the second starting value cannot be set too large, otherwise it may cause a sudden change in the duty cycle of the second lower bridge arm. For example, the second starting value can be set to 9%, 9.5%, 10%, etc., but this application embodiment does not limit this.

[0121] In some embodiments, the controller can control the second duty cycle of the second lower bridge arm to start from a preset second initial value and increase to a second target value at a second preset rate of change, so that the actual output voltage on the output side is the same as the target output voltage.

[0122] The second target value is the duty cycle of the second lower bridge arm that, given a second input voltage on the input side, ensures that the output voltage on the output side reaches the target output voltage. For example, the controller can determine the second target value using the following formula:

[0123]

[0124] Where D3 is the second target value; D2 is the first duty cycle, which is the second preset value at this time; V out1 Target output voltage; V in2 This is the second voltage.

[0125] In some embodiments, the sum of the second preset value and the second initial value can be 100% to avoid sudden changes in the actual output voltage. For example, the second preset value can be 90%, and the second initial value can be 10%.

[0126] It should be noted that V out =[D a / (1-D b )]*V in , where V out V is the output voltage on the output side. in D is the input voltage on the input side. a D is the first duty cycle of the first upper arm. b Let V be the second duty cycle of the second lower bridge arm. Then, during the process of the first duty cycle of the first upper bridge arm decreasing from the first preset value to the second preset value, in order to make V... out With V in Equally, while the first duty cycle decreases from the first preset value to the second preset value, the second duty cycle of the second lower bridge arm is increased to a second starting value that is 100% of the sum of the first and second preset values. In this way, it can be ensured that the actual output voltage on the output side will not fluctuate significantly.

[0127] It should be noted that when the controller detects a jump in the input voltage from the first voltage to the second voltage, if the first voltage is greater than the target output voltage and the second voltage is less than the target output voltage, steps 401 to 402 can be executed to make the actual output voltage on the output side the same as the target output voltage, thereby ensuring the stability of the power supply on the output side. In other cases, other operations can be used to ensure the stability of the power supply on the output side. The operations in other cases are explained below:

[0128] In some cases, if the first voltage is greater than the target output voltage and the second voltage is equal to the target output voltage, the controller increases the first duty cycle to a first preset value at a first preset rate of change. After the first duty cycle increases to the first preset value, the controller controls the first duty cycle to decrease from the first preset value to a second preset value, and controls the second duty cycle to increase to a preset second starting value; the sum of the second preset value and the second starting value is 100%.

[0129] It should be noted that if the input voltage on the input side is greater than the target output voltage, it indicates that the input voltage on the input side is high. In this case, the first duty cycle of the first upper bridge arm is greater than 0% and less than the first preset value, and the second duty cycle of the second lower bridge arm is 0%, meaning that the second lower bridge arm is in the off state. At this time, the input voltage on the input side is stepped down to the target output voltage by the first upper bridge arm, the energy storage inductor, and the second upper bridge arm, and then output to the device on the output side to charge the device on the output side.

[0130] If the input voltage before the input side transition (i.e., the first voltage) is greater than the target output voltage, and the input voltage after the input side transition (i.e., the second voltage) is equal to the target output voltage, it indicates that the input voltage on the input side has decreased, and the actual output voltage on the output side has also decreased accordingly. In this case, while maintaining the second duty cycle of the second lower bridge arm at 0%, the controller increases the first duty cycle of the first upper bridge arm to the first preset value at a first preset rate of change. In this way, the first duty cycle of the first upper bridge arm can be gradually increased, avoiding the problem of sudden changes in duty cycle. Thus, after the output voltage on the output side decreases, it can gradually increase to the target output voltage as the first duty cycle changes.

[0131] After the first duty cycle increases to a first preset value, the controller controls the first duty cycle to decrease from the first preset value to a second preset value and maintain it at the second preset value. In this way, the first upper bridge arm will have a turn-off phase during the control cycle. During the turn-off phase of the first upper bridge arm, the energy storage inductor will discharge, thus effectively controlling the current of the energy storage inductor and avoiding triggering OCP.

[0132] Furthermore, after the first duty cycle increases to a first preset value, while controlling the first duty cycle to decrease from the first preset value to a second preset value, the second duty cycle of the second lower bridge arm is controlled to increase to a preset second starting value and remain at the second starting value. Because V out =[D a / (1-D b )]*V inTherefore, while the first duty cycle decreases from the first preset value to the second preset value, the second duty cycle of the second lower bridge arm is increased to a second initial value that sums with the second preset value to 100%. This ensures that the actual output voltage on the output side will not fluctuate significantly, and at this time, the actual output voltage on the output side is equal to the input voltage on the input side, which is the target output voltage. In this way, the stability of the actual output voltage on the output side can be guaranteed even if the input voltage on the input side changes abruptly.

[0133] In some cases, if the first voltage is less than the target output voltage and the second voltage is greater than the target output voltage, the controller controls the first duty cycle to remain at a second preset value, and reduces the second duty cycle to a preset second starting value at a third preset rate of change. After the second duty cycle is reduced to the second starting value, the second lower bridge arm is stopped from being driven, and the first duty cycle is controlled to decrease at a fourth preset rate of change until the actual output voltage on the output side is the same as the target output voltage.

[0134] The third preset rate of change can be set in advance. The third preset rate of change is less than 0. For example, the third preset rate of change can be -1.8%, -1.9%, -2.0% per unit time, etc. For example, the third preset rate of change can be the opposite of the second preset rate of change, or it can be other values.

[0135] The fourth preset rate of change can be preset. The fourth preset rate of change is less than 0. For example, the fourth preset rate of change can be -1.8%, -1.9%, -2.0% per unit time, etc. For example, the fourth preset rate of change can be the opposite of the first preset rate of change, or it can be other values.

[0136] It should be noted that if the input voltage on the input side is less than the target output voltage, it indicates that the input voltage on the input side is too low. In this case, the DC / DC converter circuit can operate in buck-boost mode, with the first duty cycle of the first upper bridge arm being the second preset value and the second duty cycle of the second lower bridge arm being the second target value. At this time, the input voltage on the input side is boosted to the target output voltage by the DC / DC converter circuit and then output to the device on the output side to power the device.

[0137] If the input voltage before the input transition (i.e., the first voltage) is less than the target output voltage, and the input voltage after the input transition (i.e., the second voltage) is greater than the target output voltage, it indicates that the input voltage on the input side has transitioned from a lower voltage to a higher voltage, and the actual output voltage also increases accordingly. In this case, the controller can maintain the first duty cycle of the first upper bridge arm at a second preset value while reducing the second duty cycle of the second lower bridge arm to a second initial value at a third preset rate of change. In this way, the second duty cycle of the second lower bridge arm can be gradually reduced, avoiding the problem of sudden changes in duty cycle. As a result, after the actual output voltage on the output side suddenly increases due to the input voltage transition, it can gradually decrease with the change of the second duty cycle.

[0138] After the second duty cycle of the second lower bridge arm decreases to the second initial value, driving the second lower bridge arm is stopped, that is, the second duty cycle of the second lower bridge arm is reduced from the second initial value to 0% to turn off the second lower bridge arm. At the same time, the first duty cycle of the first upper bridge arm is controlled to decrease at a fourth preset rate of change to gradually reduce the actual output voltage on the output side until the actual output voltage on the output side is the same as the target output voltage. In this way, the stability of the actual output voltage on the output side can be guaranteed even if the input voltage on the input side changes abruptly.

[0139] In some embodiments, the operation of the controller controlling the first duty cycle to decrease at a fourth preset rate of change until the actual output voltage on the output side is the same as the target output voltage can be as follows: while the controller reduces the second duty cycle from a second initial value to 0%, it increases the first duty cycle from a second preset value to a first preset value, and then controls the first duty cycle to decrease from the first preset value at a fourth preset rate of change until the actual output voltage on the output side is the same as the target output voltage.

[0140] For example, the sum of the second preset value and the second initial value can be 100%. In this way, while reducing the second duty cycle from the second initial value to 0%, increasing the first duty cycle from the second preset value to a first preset value that is 100% of the sum of the second and the second initial values ​​can ensure that the actual output voltage on the output side does not fluctuate significantly.

[0141] In some embodiments, the controller may control the first duty cycle to start from a first preset value and decrease to a first target value at a fourth preset rate of change, so that the actual output voltage on the output side is the same as the target output voltage.

[0142] When the input voltage on the input side is the second voltage and the actual output voltage on the output side is the target output voltage, the duty cycle corresponding to the first upper bridge arm can be calculated as the first target value according to the formula provided above. For example, the controller can determine the ratio between the target output voltage and the second voltage as the first target value.

[0143] In some cases, if the first voltage is less than the target output voltage and the second voltage is equal to the target output voltage, the controller controls the first duty cycle to remain at a second preset value, and reduces the second duty cycle to a preset second starting value at a third preset rate of change. The sum of the second preset value and the second starting value is 100%.

[0144] It should be noted that if the input voltage on the input side is less than the target output voltage, it indicates that the input voltage on the input side is a low voltage. In this case, the first duty cycle of the first upper bridge arm is the second preset value, and the second duty cycle of the second lower bridge arm is the second target value. At this time, the input voltage on the input side is boosted to the target output voltage by the DC / DC converter circuit and then output to the device on the output side to power the device on the output side.

[0145] If the input voltage before the input transition (i.e., the first voltage) is less than the target output voltage, and the input voltage after the input transition (i.e., the second voltage) is equal to the target output voltage, it indicates that the input voltage on the input side has transitioned from a lower voltage to the target output voltage, and the actual output voltage also increases accordingly. In this case, while maintaining the first duty cycle of the first upper bridge arm at the second preset value, the second duty cycle of the second lower bridge arm is reduced to the second initial value at a third preset rate of change. In this way, the second duty cycle of the second lower bridge arm can be gradually reduced, avoiding the problem of sudden changes in duty cycle. Thus, after the actual output voltage on the output side suddenly increases due to the input voltage transition, it can gradually decrease again.

[0146] After the first duty cycle is maintained at the second preset value and the second duty cycle decreases to the second initial value and remains at the second initial value, since the sum of the second preset value and the second initial value is 100%, V out =[D a / (1-D b )]*V in As can be seen, the actual output voltage on the output side is equal to the input voltage on the input side at this time, which is the target output voltage. In this way, the stability of the actual output voltage on the output side can be guaranteed even if the input voltage on the input side changes abruptly.

[0147] In some cases, if both the first voltage and the second voltage are greater than the target output voltage, the controller determines the ratio between the target output voltage and the second voltage as the first target value of the first duty cycle, and controls the first duty cycle to be adjusted to the first target value at a fifth preset rate of change.

[0148] The fifth preset rate of change can be set in advance. If the adjustment requirement is to decrease the first duty cycle, the fifth preset rate of change will be less than 0; if the adjustment requirement is to increase the first duty cycle, the fifth preset rate of change will be greater than 0.

[0149] When the input voltage on the input side is the second voltage and the actual output voltage on the output side is the target output voltage, the first duty cycle corresponding to the first upper bridge arm can be calculated as the first target value according to the formula provided above.

[0150] In some embodiments, after calculating the first target value, the first duty cycle can be adjusted to the first target value so that the actual output voltage is adjusted to the target output voltage.

[0151] In other embodiments, the first duty cycle can be adjusted until the actual output voltage is adjusted to the target output voltage. When the actual output voltage is the target output voltage, the value of the first duty cycle is the first target value.

[0152] It should be noted that if the input voltage on the input side is greater than the target output voltage, it indicates that the input voltage on the input side is a relatively high voltage. In this case, the first duty cycle of the first upper bridge arm is greater than 0% and less than the first preset value, and the second duty cycle of the second lower bridge arm is 0%, meaning that the second lower bridge arm is in the off state. At this time, the input voltage on the input side is stepped down to the target output voltage by the first upper bridge arm, the energy storage inductor, and the second upper bridge arm, and then output to the device on the output side to supply power to the device on the output side.

[0153] If both the input voltage before the input transition (i.e., the first voltage) and the input voltage after the input transition (i.e., the second voltage) are greater than the target output voltage, it indicates that the input voltage on the input side is consistently higher than the target output voltage, requiring the DC / DC converter circuit to operate in buck mode. In this case, while maintaining the second duty cycle of the second lower bridge arm at 0%, the controller can directly adjust the first duty cycle to the first target value corresponding to the second voltage using a fifth preset rate of change, so that the actual output voltage on the output side can be adjusted to the target output voltage. This ensures the stability of the actual output voltage on the output side even when the input voltage on the input side changes.

[0154] In some embodiments, the operation of the controller controlling the first duty cycle to adjust to the first target value at a fifth preset rate of change can be: the controller controlling the first duty cycle to start from the first initial value and adjust to the first target value at a fifth preset rate of change.

[0155] The first initial value is the duty cycle of the first upper bridge arm when the input voltage on the input side is a first voltage. For example, the controller can determine the first initial value as the ratio between the target output voltage and the first voltage.

[0156] If the first initial value is greater than the first target value, then the fifth preset rate of change is less than 0. In this case, the controller controls the first duty cycle to decrease from the first initial value to the first target value using the fifth preset rate of change. If the first initial value is less than the first target value, then the fifth preset rate of change is greater than 0. In this case, the controller controls the first duty cycle to increase from the first initial value to the first target value using the fifth preset rate of change.

[0157] In some cases, if both the first voltage and the second voltage are less than the target output voltage, the controller determines the second target value of the second duty cycle based on the first duty cycle, the second voltage, and the target output voltage, and controls the second duty cycle to be adjusted to the second target value at a sixth preset rate of change.

[0158] The sixth preset rate of change can be set in advance. If the adjustment requirement is to decrease the second duty cycle, the sixth preset rate of change will be less than 0; if the adjustment requirement is to increase the second duty cycle, the sixth preset rate of change will be greater than 0.

[0159] When the input voltage on the input side is the second voltage and the actual output voltage on the output side is the target output voltage, the second duty cycle corresponding to the second lower bridge arm can be calculated as the second target value according to the formula provided above.

[0160] In some embodiments, after calculating the second target value, the second duty cycle can be adjusted to the second target value so that the actual output voltage is adjusted to the target output voltage.

[0161] In other embodiments, the second duty cycle can be adjusted until the actual output voltage is adjusted to the target output voltage. When the actual output voltage is the target output voltage, the value of the second duty cycle is the second target value.

[0162] It should be noted that if the input voltage on the input side is less than the target output voltage, it indicates that the input voltage on the input side is a low voltage. In this case, the first duty cycle of the first upper bridge arm is the second preset value, and the second duty cycle of the second lower bridge arm is the third initial value. At this time, the input voltage on the input side is boosted to the target output voltage by the DC / DC converter circuit and then output to the device on the output side to power the device on the output side.

[0163] If both the input voltage before the input voltage jump (i.e., the first voltage) and the input voltage after the input voltage jump (i.e., the second voltage) are less than the target output voltage, it indicates that the DC / DC converter circuit can always operate in buck-boos mode. In this case, while maintaining the first duty cycle at the second preset value, the controller can directly adjust the second duty cycle to the second target value corresponding to the second voltage at a sixth preset rate of change, so that the actual output voltage on the output side can be adjusted to the target output voltage. In this way, the stability of the actual output voltage on the output side can be guaranteed even when the input voltage on the input side jumps.

[0164] For example, the controller can determine the second target value using the following formula:

[0165]

[0166] Where D3 is the second target value; D2 is the first duty cycle, which is the second preset value at this time; V out1 Target output voltage; V in2 This is the second voltage.

[0167] In some embodiments, the operation of the controller controlling the second duty cycle to adjust to the second target value at a sixth preset rate of change can be: the controller controls the second duty cycle to start from a third initial value and adjust to the second target value at a sixth preset rate of change.

[0168] When the input voltage on the input side is the first voltage, and the actual output voltage on the output side is the target output voltage, the second duty cycle corresponding to the second lower bridge arm is the third initial value. For example, the controller can determine the third initial value using the following formula:

[0169]

[0170] Where D4 is the third initial value; D2 is the first duty cycle, which is the second preset value at this time; V out1 Target output voltage; V in1 This is the first voltage.

[0171] If the third initial value is greater than the second target value, then the sixth preset rate of change is less than 0. In this case, the controller controls the second duty cycle to decrease from the third initial value to the second target value using the sixth preset rate of change. If the third initial value is less than the second target value, then the sixth preset rate of change is greater than 0. In this case, the controller controls the second duty cycle to increase from the third initial value to the second target value using the sixth preset rate of change.

[0172] In this embodiment, when the input voltage on the input side is detected to jump from a first voltage to a second voltage, if the first voltage is greater than the target output voltage of the DC / DC converter circuit and the second voltage is less than the target output voltage, then the first duty cycle of the first upper bridge arm is increased to a first preset value at a first preset rate of change. In this way, the first duty cycle of the first upper bridge arm can gradually increase, so that after the actual output voltage on the output side decreases due to the decrease in input voltage, it can gradually increase back to the target output voltage.

[0173] After the first duty cycle increases to the first preset value, the first duty cycle is controlled to decrease from the first preset value to the second preset value and remain at the second preset value. The second duty cycle of the second lower bridge arm is controlled to increase at the second preset rate of change until the actual output voltage of the DC / DC converter circuit is the same as the target output voltage.

[0174] Thus, the overall rate of increase of the energy storage inductor current is relatively small, while the overall rate of decrease of the energy storage inductor current is relatively large. Therefore, the current of the energy storage inductor can be well controlled, avoiding triggering OCP. Furthermore, since the second duty cycle of the second lower bridge arm will increase until the actual output voltage on the output side is the same as the target output voltage, the stability of the actual output voltage on the output side can be guaranteed even if the input voltage on the input side changes abruptly.

[0175] To facilitate understanding, the following will be combined with... Figures 5 to 10 The control method of the above DC / DC converter circuit is illustrated by example. In the figure, D refers to the duty cycle, which is expressed as %, D1 refers to the first duty cycle, D2 refers to the second duty cycle, and T refers to time.

[0176] Assuming the first preset value is 100%, the first preset change rate is 2.0% per unit time, the second preset value is 90%, the second preset change rate is 2.5% per unit time, the second initial value is 10%, the target output voltage is 64V, the third preset change rate is -2.5% per unit time, the fourth preset change rate is -2.0% per unit time, the fifth preset change rate is -1.5% per unit time, the sixth preset change rate is -2.0% per unit time, and the sum of the second preset value and the second initial value is 100%.

[0177] In the first scenario, assuming the controller detects a jump in the input voltage on the input side from a first voltage of 150V to a second voltage of 7V, then see... Figure 5 , Figure 5 This is a schematic diagram of the control process of a DC / DC converter circuit provided in an embodiment of this application. The control process may include a first stage and a second stage.

[0178] Phase 1: The controller determines the initial value of D1 to be approximately 43% based on the target output voltage of 64V and the initial voltage of 150V. While maintaining D2 at 0%, the controller controls D1... Figures 5 to 10 (All values ​​are represented by solid lines) Starting from 43%, it increases at a rate of 2.0% per unit time. After D1 increases to 100% at time t1, the controller reduces D1 from 100% to 90%, while simultaneously controlling D2 (…). Figures 5 to 10 (The percentage is represented by dashed lines) increasing from 0% to 10%.

[0179] In the second stage: the controller determines the second target value of D2 to be 90% based on the target output voltage of 64V, the second voltage of 7V, and the second preset value of 90%. While keeping D1 at 90%, the controller controls D2 to increase from 10% at a rate of 2.5% per unit time. At time t2, D2 increases to 90% to adjust the actual output voltage on the output side to the target output voltage of 64V.

[0180] In the second scenario, assuming the controller detects a jump in the input voltage on the input side from a first voltage of 7V to a second voltage of 30V, then see... Figure 6 , Figure 6 This is a schematic diagram of the control process of a DC / DC converter circuit provided in an embodiment of this application.

[0181] The controller determines a third initial value of 90% for D2 based on the target output voltage of 64V, a first voltage of 7V, and a first duty cycle of 90%. The controller then determines a second target value of approximately 58% for D2 based on the target output voltage of 64V, a second voltage of 30V, and a first duty cycle of 90%. Subsequently, while maintaining D1 at 90%, the controller controls D2 to decrease from 90% at a rate of -2.0% per unit time. At time t3, D2 decreases to 58% to adjust the actual output voltage on the output side to the target output voltage of 64V.

[0182] In the third case, assuming the controller detects a jump in the input voltage on the input side from a first voltage of 30V to a second voltage of 64V, then see... Figure 7 , Figure 7 This is a schematic diagram of the control process of a DC / DC converter circuit provided in an embodiment of this application.

[0183] With an input voltage of 30V, an actual output voltage of 64V, and D1 at 90%, D2 can be calculated to be 58%.

[0184] Therefore, when the input voltage jumps from the first voltage of 30V to the second voltage of 64V, the controller, while keeping D1 at 90%, reduces D2 from 58% at a rate of -2.5% per unit time. At time t4, D2 decreases to 10% to adjust the actual output voltage on the output side to the target output voltage of 64V.

[0185] In the fourth case, assuming the controller detects that the input voltage on the input side jumps from a first voltage of 7V to a second voltage of 80V, then as follows... Figure 8 As shown, Figure 8 This is a schematic diagram of the control process of a DC / DC converter circuit provided in an embodiment of this application. The control process may include a first stage and a second stage.

[0186] With an input voltage of 7V, an actual output voltage of 64V, and D1 at 90%, D2 can be calculated to be 90%.

[0187] Phase 1: With control D1 maintained at 90%, the controller controls D2, starting from 90%, to decrease at a rate of -2.5% per unit time. At time t5, D2 decreases to 10%.

[0188] Phase Two: The controller determines the first target value of D1 to be 80% based on the second voltage of 80V and the target output voltage of 64V. When D2 decreases to 10%, D1 is increased to 100% while D2 is decreased to 0%. After D1 increases to 100%, while D2 remains at 0%, D1 is decreased at a rate of -2.0% per unit time. At time t6, D1 decreases to 80% to adjust the actual output voltage on the output side to the target output voltage of 64V.

[0189] In the fifth scenario, assuming the controller detects a jump in the input voltage from a first voltage of 80V to a second voltage of 90V, then see... Figure 9 , Figure 9 This is a schematic diagram of the control process of a DC / DC converter circuit provided in an embodiment of this application.

[0190] The controller determines the initial value of D1 to be 80% based on the first voltage of 80V and the target output voltage of 64V, and determines the first target value of D1 to be 71% based on the second voltage of 90V and the target output voltage of 64V. Then, while keeping D2 at 0%, control D1 starts at 80% and decreases at a rate of -1.5% per unit time. At time t7, D1 decreases to 71% to adjust the actual output voltage on the output side to the target output voltage of 64V.

[0191] In the sixth scenario, assuming the controller detects a jump in the input voltage from a first voltage of 90V to a second voltage of 64V, then see... Figure 10 , Figure 10 This is a schematic diagram of the control process of a DC / DC converter circuit provided in an embodiment of this application. The control process may include a first stage and a second stage.

[0192] Phase 1: The controller determines the initial value of D1 to be 71% based on the initial voltage of 90V and the target output voltage of 64V. Afterwards, while keeping D2 at 0%, D1 increases from 71% at a rate of 2.0% per unit time. At time t8, D1 increases to 100%.

[0193] Second stage: After D1 increases to 100%, the controller controls D1 to decrease to 90%, while simultaneously controlling D2 to increase to 10%, so that the actual output voltage on the output side is adjusted to the target output voltage of 64V.

[0194] Figure 11 This is a schematic diagram of the structure of a control device for a DC / DC converter circuit provided in an embodiment of this application. This device can be implemented by software, hardware, or a combination of both, serving as part or all of the controller in the DC / DC converter circuit. See also... Figure 11 The device includes: a first enlargement module 1101 and a first control module 1102.

[0195] The first amplification module 1101 is used to gradually increase the first duty cycle of the first upper bridge arm to a first preset value when the input voltage on the input side is detected to jump from the first voltage to the second voltage, if the first voltage is greater than the target output voltage of the DC / DC conversion circuit and the second voltage is less than the target output voltage.

[0196] The first control module 1102 is used to control the first duty cycle to decrease from the first preset value to a second preset value and maintain it at the second preset value after the first duty cycle increases to the first preset value, and to control the second duty cycle of the second lower bridge arm to gradually increase until the actual output voltage of the DC / DC conversion circuit is the same as the target output voltage.

[0197] In some possible implementations, the first enlargement module 1101 is used for:

[0198] Increase the first duty cycle of the first upper bridge arm to a first preset value by a first preset rate of change;

[0199] The first control module 1102 is used for:

[0200] The second duty cycle of the second lower bridge arm is increased by a second preset rate of change until the actual output voltage of the DC / DC converter circuit is the same as the target output voltage.

[0201] In some possible implementations, the first enlargement module 1101 is used for:

[0202] When the input voltage is detected to jump from the first voltage to the second voltage, the ratio between the target output voltage and the first voltage is determined as the first starting value of the first duty cycle;

[0203] The first duty cycle of the first upper bridge arm is increased from the first initial value to the first preset value at a first preset rate of change.

[0204] In some possible implementations, the control module 1102 is used for:

[0205] The second duty cycle of the second lower bridge arm is controlled to start from a preset second initial value and increase at a second preset rate of change until the actual output voltage is the same as the target output voltage.

[0206] In some possible implementations, the device also includes:

[0207] The second amplification module is used to increase the first duty cycle to a first preset value by a first preset rate of change if the first voltage is greater than the target output voltage and the second voltage is equal to the target output voltage.

[0208] The second control module is used to control the first duty cycle to decrease from the first preset value to the second preset value after the first duty cycle increases to the first preset value, and to control the second duty cycle to increase to the preset second starting value; the sum of the second preset value and the second starting value is 100%.

[0209] In some possible implementations, the device further includes a first reduction module, which is used to:

[0210] If the first voltage is less than the target output voltage and the second voltage is greater than the target output voltage, then the first duty cycle is controlled to remain at the second preset value, and the second duty cycle is reduced to the preset second starting value at a third preset rate of change.

[0211] After the second duty cycle decreases to the second initial value, the second lower bridge arm is stopped from being driven, and the first duty cycle is controlled to decrease at the fourth preset rate of change until the actual output voltage is the same as the target output voltage.

[0212] In some possible implementations, the device also includes:

[0213] The second reduction module is configured to, if the first voltage is less than the target output voltage and the second voltage is equal to the target output voltage, control the first duty cycle to remain at a second preset value, and reduce the second duty cycle to a preset second starting value at a third preset rate of change; the sum of the second preset value and the second starting value is 100%.

[0214] In some possible implementations, the device also includes:

[0215] The first determining module is used to determine the ratio between the target output voltage and the second voltage as the first target value of the first duty cycle if both the first voltage and the second voltage are greater than the target output voltage.

[0216] The third control module is used to control the first duty cycle to be adjusted to the first target value by the fifth preset change rate.

[0217] In some possible implementations, the device also includes:

[0218] The second determining module is used to determine a second target value for the second duty cycle based on the first duty cycle, the second voltage, and the target output voltage if both the first voltage and the second voltage are less than the target output voltage.

[0219] The fourth control module is used to control the second duty cycle to be adjusted to the second target value at the sixth preset rate of change.

[0220] In this embodiment, when the input voltage on the input side is detected to jump from a first voltage to a second voltage, if the first voltage is greater than the target output voltage of the DC / DC converter circuit and the second voltage is less than the target output voltage, the first duty cycle of the first upper bridge arm is gradually increased to a first preset value. This allows the first duty cycle of the first upper bridge arm to gradually increase, so that the output voltage on the output side, after decreasing, can gradually increase back to the second voltage. After the first duty cycle increases to the first preset value, the first duty cycle is controlled to decrease from the first preset value to a second preset value and remain at the second preset value, while the second duty cycle of the second lower bridge arm is controlled to gradually increase until the actual output voltage of the DC / DC converter circuit is the same as the target output voltage. Thus, the overall rate of increase of the energy storage inductor current is small, and the overall rate of decrease of the energy storage inductor current is large, thereby effectively controlling the current of the energy storage inductor and avoiding triggering OCP. Furthermore, since the second duty cycle of the second lower bridge arm increases until the actual output voltage on the output side is the same as the target output voltage, the stability of the actual output voltage on the output side can be guaranteed even when the input voltage on the input side jumps.

[0221] It should be noted that the control device for the DC / DC converter circuit provided in the above embodiments is only illustrated by the division of the above functional modules when controlling the DC / DC converter circuit. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0222] The functional units and modules in the above embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of the embodiments of this application.

[0223] The control device for the DC / DC converter circuit and the control method for the DC / DC converter circuit provided in the above embodiments belong to the same concept. The specific working process and technical effects of the units and modules in the above embodiments can be found in the method embodiments section, and will not be repeated here.

[0224] This application also provides an energy storage device, which includes a battery pack and a DC / DC converter circuit. The output side of the DC / DC converter circuit is connected to the battery pack to charge the battery pack. The DC / DC converter circuit includes at least one processor, a memory, and a computer program stored in the memory and executable on the at least one processor. When the processor executes the computer program, it implements the steps in any of the above-described method embodiments.

[0225] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, can implement the steps in the various method embodiments described above.

[0226] This application provides a computer program product that, when run on a computer, causes the computer to perform the steps described in the various method embodiments above.

[0227] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, all or part of the processes in the above method embodiments of this application can be implemented by a computer program instructing related hardware. This computer program can be stored in a computer-readable storage medium, and when executed by a processor, it can implement the steps of the various method embodiments described above. The computer program includes computer program code, which can be in the form of source code, object code, executable files, or some intermediate form. The computer-readable medium can include at least: any entity or device capable of carrying the computer program code to a photographing device / terminal device, a recording medium, a computer memory, ROM (Read-Only Memory), RAM (Random Access Memory), CD-ROM (Compact Disc Read-Only Memory), magnetic tape, floppy disk, and optical data storage devices. The computer-readable storage medium mentioned in this application can be a non-volatile storage medium; in other words, it can be a non-transient storage medium.

[0228] It should be understood that all or part of the steps of the above embodiments can be implemented by software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented in whole or in part as a computer program product. The computer program product includes one or more computer instructions. The computer instructions can be stored in the above-described computer-readable storage medium.

[0229] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0230] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0231] In the embodiments provided in this application, it should be understood that the disclosed apparatus / computer devices and methods can be implemented in other ways. For example, the apparatus / computer device embodiments described above are merely illustrative. For instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0232] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0233] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A control method for a DC / DC converter circuit, characterized in that, The DC / DC converter circuit includes a first bridge arm unit connected to the input side, a second bridge arm unit connected to the output side, and an energy storage inductor; the energy storage inductor is connected at the midpoint between the first bridge arm unit and the second bridge arm unit; the first bridge arm unit includes a first upper bridge arm and a first lower bridge arm connected in series; the second bridge arm unit includes a second upper bridge arm and a second lower bridge arm connected in series; both the first upper bridge arm and the second lower bridge arm include a controllable switching transistor; the control method includes: When the input voltage on the input side is detected to jump from a first voltage to a second voltage, if the first voltage is greater than the target output voltage of the DC / DC converter circuit and the second voltage is less than the target output voltage, the first duty cycle of the first upper bridge arm is gradually increased from a first initial value to a first preset value, where the first initial value is the ratio of the target output voltage to the first voltage. After the first duty cycle increases to the first preset value, the first duty cycle is controlled to decrease from the first preset value to the second preset value and remain at the second preset value, so that the DC / DC conversion circuit works in BUCK-BOOST mode, and the second duty cycle of the second lower bridge arm is controlled to gradually increase from the second initial value until the actual output voltage of the DC / DC conversion circuit is the same as the target output voltage. The setting of the second initial value satisfies the requirement that the second lower bridge arm is fully turned on and there is no sudden change in duty cycle. Among them, V out =[D a / (1-D b )]*V in V out V is the output voltage on the output side. in D is the input voltage on the input side. a D is the first duty cycle of the first upper bridge arm. b The second duty cycle is the second lower bridge arm.

2. The method as described in claim 1, characterized in that, The step of gradually increasing the first duty cycle of the first upper bridge arm from a first initial value to a first preset value includes: The first duty cycle of the first upper bridge arm is increased from the first initial value to the first preset value by a first preset rate of change. The process of gradually increasing the second duty cycle of the second lower bridge arm from a second initial value until the actual output voltage of the DC / DC converter circuit is the same as the target output voltage includes: The second duty cycle of the second lower bridge arm is controlled to increase from the second initial value at a second preset rate of change until the actual output voltage of the DC / DC converter circuit is the same as the target output voltage.

3. The method as described in claim 2, characterized in that, Before increasing the first duty cycle of the first upper bridge arm from the first initial value to the first preset value at a first preset rate of change, the method further includes: When the input voltage is detected to jump from the first voltage to the second voltage, the ratio between the target output voltage and the first voltage is determined as the first starting value of the first duty cycle.

4. The method as described in claim 2, characterized in that, The step of controlling the second duty cycle of the second lower bridge arm to increase from the second initial value at a second preset rate of change until the actual output voltage of the DC / DC converter circuit is the same as the target output voltage includes: The second duty cycle of the second lower bridge arm is controlled to increase from the second initial value at the second preset rate of change until the actual output voltage is the same as the target output voltage.

5. The method as described in any one of claims 2 to 4, characterized in that, The method further includes: If the first voltage is greater than the target output voltage and the second voltage is equal to the target output voltage, then the first duty cycle is increased to the first preset value by the first preset rate of change. After the first duty cycle increases to the first preset value, the first duty cycle is controlled to decrease from the first preset value to the second preset value, and the second duty cycle is controlled to increase to the second starting value; the sum of the second preset value and the second starting value is 100%.

6. The method according to any one of claims 2 to 4, characterized in that, The method further includes: If the first voltage is less than the target output voltage and the second voltage is greater than the target output voltage, then the first duty cycle is controlled to remain at the second preset value, and the second duty cycle is reduced to the second initial value at a third preset rate of change. After the second duty cycle decreases to the second initial value, the driving of the second lower bridge arm is stopped, and the first duty cycle is controlled to decrease at a fourth preset rate of change until the actual output voltage is the same as the target output voltage.

7. The method as described in any one of claims 2 to 4, characterized in that, The method further includes: If the first voltage is less than the target output voltage and the second voltage is equal to the target output voltage, then the first duty cycle is controlled to remain at the second preset value, and the second duty cycle is reduced to the second initial value at a third preset rate of change; the sum of the second preset value and the second initial value is 100%.

8. The method according to any one of claims 2 to 4, characterized in that, The method further includes: If both the first voltage and the second voltage are greater than the target output voltage, then the ratio between the target output voltage and the second voltage is determined as the first target value of the first duty cycle; The first duty cycle is controlled to be adjusted to the first target value at a fifth preset rate of change.

9. A DC / DC converter circuit, characterized in that, The DC / DC converter circuit includes a first bridge arm unit connected to the input side, a second bridge arm unit connected to the output side, an energy storage inductor, and a controller; the energy storage inductor is connected at the midpoint between the first bridge arm unit and the second bridge arm unit; the first bridge arm unit includes a first upper bridge arm and a first lower bridge arm connected in series; the second bridge arm unit includes a second upper bridge arm and a second lower bridge arm connected in series; both the first upper bridge arm and the second lower bridge arm include a controllable switch; the controller is used to execute the method as described in any one of claims 1 to 8.

10. An energy storage device, characterized in that, The energy storage device includes a battery pack and a DC / DC converter circuit as described in claim 9, wherein the output side of the DC / DC converter circuit is connected to the battery pack to charge the battery pack.

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