Voltage conversion circuit and control method thereof, electronic device and storage medium

Abstract

The present application relates to a voltage conversion circuit, a control method thereof, an electronic device, and a storage medium. In this method, a main control circuit obtains a first duty cycle of a fourth switch tube of the voltage conversion circuit and an input current flowing through an inductor; controls the first switch tube of the voltage conversion circuit to be turned on and the third switch tube to be turned off. When the input current is less than a first preset value, the main control circuit controls the fourth switch tube to be turned on at the first duty cycle and controls the second switch tube of the voltage conversion circuit to be turned off. The main control circuit calculates a second duty cycle of the second switch tube based on the first duty cycle and updates the second duty cycle using the dead time of the voltage conversion circuit. When the input current is greater than or equal to the first preset value and less than the required current of the external device, the main control circuit controls the fourth switch tube to be turned on at the first duty cycle and controls the second switch tube to be turned on at the third duty cycle. The present application can solve the problem of current jitter caused by the dead time in the voltage conversion circuit.

Description

Technical Field

[0001] The present invention relates to the field of energy storage devices, and in particular to a control method for a voltage conversion circuit, electronic equipment, a voltage conversion circuit, and a storage medium. Background Art

[0002] A voltage conversion circuit may be provided in an electronic device. The voltage conversion circuit (eg, an H-bridge buck-boost circuit) may be used to boost or buck voltage.

[0003] In related technologies, when a voltage conversion circuit is used to boost the voltage, a dead time may easily occur in the voltage conversion circuit during the current rising phase of the voltage conversion circuit, causing current jitter, which affects the normal voltage boosting and lowering of the electronic equipment, and there is also a risk of explosion of the electronic equipment. Summary of the Invention

[0004] The present application provides a control method for a voltage conversion circuit, an electronic device, a voltage conversion circuit, and a storage medium to solve the problem in related technologies of current jitter in the voltage conversion circuit during the current rising phase when the voltage conversion circuit is used to boost voltage.

[0005] The present application provides a control method for a voltage conversion circuit, wherein the voltage conversion circuit includes a first switching tube, a second switching tube, a third switching tube, a fourth switching tube, and an inductor, wherein the first end of the first switching tube is used to connect to a first voltage input end, the second end of the first switching tube is connected to the first end of the third switching tube, the second end of the third switching tube is used to connect to a second voltage input end, the first end of the second switching tube is used to connect to a first voltage output end, the second end of the second switching tube is connected to the first end of the fourth switching tube, and the second end of the fourth switching tube is used to connect to a second voltage output end, the first voltage input end and the second voltage input end are used to connect to a power supply device, the first voltage output end and the second voltage output end are used to connect to an external device, the first end of the inductor is connected between the first switching tube and the third switching tube, and the second switching tube includes a body diode The method includes: obtaining a first duty cycle of the fourth switching tube and an input current flowing through the inductor; controlling the first switching tube to remain on and the third switching tube to remain off; when the input current is less than a first preset value, controlling the fourth switching tube to be turned on with the first duty cycle and controlling the second switching tube to be turned off; obtaining a required current of the external device and a dead time of the voltage conversion circuit; calculating a second duty cycle of the second switching tube based on the first duty cycle, and updating the second duty cycle using the dead time to obtain a third duty cycle; and when the input current is greater than or equal to the first preset value and less than the required current, controlling the fourth switching tube to be turned on with the first duty cycle and controlling the second switching tube to be turned on with the third duty cycle.

[0006] When performing a boost conversion, the voltage conversion circuit of the present application obtains the first duty cycle of the fourth switch and the input current flowing through the inductor. When the input current is less than a first preset value, the fourth switch is controlled to conduct at the first duty cycle and the second switch is controlled to disconnect. The required current of the external device and the dead time of the voltage conversion circuit are then obtained, and the second duty cycle of the second switch is updated using the dead time to obtain a third duty cycle. Finally, the fourth switch is controlled to conduct at the first duty cycle and the second switch is controlled to conduct at the updated third duty cycle. The solution of the present application uses the dead time to update the second duty cycle of the second switch while maintaining the duty cycle of the fourth switch unchanged. Therefore, the normal operation of the voltage conversion circuit can be ensured while avoiding the impact of the dead time on the fourth switch. This also avoids the problem of current jitter in the fourth switch due to the influence of the dead time, thereby improving the stability and safety of the voltage conversion circuit during boost conversion.

[0007] In a second aspect, the present application provides a voltage conversion circuit, comprising a main control circuit, a first switching tube, a second switching tube, a third switching tube, a fourth switching tube, and an inductor, wherein the first end of the first switching tube is used to connect to a first voltage input end, the second end of the first switching tube is connected to the first end of the third switching tube, the second end of the third switching tube is used to connect to a second voltage input end, the first end of the second switching tube is used to connect to a first voltage output end, the second end of the second switching tube is connected to the first end of the fourth switching tube, and the second end of the fourth switching tube is used to connect to a second voltage output end. The first voltage input end and the second voltage input and output ends are used to connect to a power supply device, and the first voltage output end and the second voltage output end are used to connect to an external device. The first end of the inductor is connected between the first and third switching tubes, the second switching tube includes a body diode, and the second end of the inductor is connected between the second and fourth switching tubes. The main control circuit is connected to the control ends of the first, second, third, and fourth switching tubes and is used to perform the above method.

[0008] In a third aspect, the present application provides an electronic device, comprising: a battery module; the above-mentioned voltage conversion circuit, wherein the battery module is connected to the first voltage output terminal and the second voltage output terminal.

[0009] In a fourth aspect, the present application provides a computer storage medium storing program instructions. When the program instructions are executed on an energy storage device, the energy storage device executes the above-mentioned voltage conversion circuit control method. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is an application scenario diagram of a control method for a voltage conversion circuit in one embodiment of the present application.

[0011] Figure 2 This is a flow chart of a control method for a voltage conversion circuit in one embodiment of the present application.

[0012] Figure 3 Schematic diagram of input current and the conduction time of the fourth switch tube and the second switch tube in one embodiment of the present application.

[0013] Figure 4 Schematic diagram of the input current and the conduction time of the fourth switch tube and the second switch tube in the existing solution of this application.

[0014] Figure 5 This is a flow chart for obtaining the first duty cycle of the fourth switch tube in one embodiment of the present application.

[0015] Figure 6 This is a flow chart of updating the second duty cycle by using the dead time in one embodiment of the present application.

[0016] Figure 7 A schematic diagram of a control device for a voltage conversion circuit provided in one embodiment of the present application.

[0017] Figure 8 A schematic diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0018] In order to more clearly understand the above-mentioned objectives, features and advantages of the present application, the present application is described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application pertains. The terms used herein in the specification of this application are for the purpose of describing embodiments in one embodiment only and are not intended to limit this application.

[0020] It should be noted that the terms "first", "second", "third", "fourth" and the like (if any) in the specification, claims and drawings of this application are used to distinguish similar objects, rather than to describe a specific order or sequence. In the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a concrete way.

[0021] It should also be noted that the methods disclosed in the embodiments of this application or the methods shown in the flowcharts include one or more steps for implementing the methods. Without departing from the scope of the claims, the order of executing multiple steps can be interchanged with each other, and some steps can also be deleted. Some embodiments will be described below with reference to the accompanying drawings. The following embodiments and features of the embodiments may be combined with each other unless there is a conflict.

[0022] When using a voltage conversion circuit to boost voltage, dead time occurs during the alternating conduction of the individual switches in the voltage conversion circuit during the current rise phase. However, when this dead time is applied to the switches, it can easily cause current jitter, affecting the normal boosting of electronic devices and posing a risk of device failure. To address this issue, the present application discloses the following solution.

[0023] refer to Figure 1FIG2 is an application scenario diagram of a control method for a voltage conversion circuit according to an embodiment of the present application. The method is applied to a voltage conversion circuit 10 and is used to compensate the duty cycle of the switching tube of the voltage conversion circuit when the voltage conversion circuit is performing a voltage boost to avoid current jitter during the rising phase of the voltage conversion circuit.

[0024] In one embodiment of the present application, a voltage conversion circuit 10 includes a first switching transistor Q1, a second switching transistor Q2, a third switching transistor Q3, a fourth switching transistor Q4, and an inductor L. The first end of the first switching transistor Q1 is connected to the first voltage input terminal VIN1, and the second end of the first switching transistor Q1 is connected to the first end of the third switching transistor Q3. The second end of the third switching transistor Q3 is connected to the second voltage input terminal VIN2. The first end of the second switching transistor Q2 is connected to the first voltage output terminal VOUT1, and the second end of the second switching transistor Q2 is connected to the first end of the fourth switching transistor Q4. The second end of the fourth switching transistor Q4 is connected to the second voltage output terminal VOUT2. The first voltage input terminal VIN1 and the second voltage input terminal VIN2 are connected to a power supply device. The first voltage output terminal VOUT1 and the second voltage output terminal VOUT2 are connected to external devices. The first end of the inductor L is connected between the first switching transistor Q1 and the third switching transistor Q3, and the second end of the inductor L is connected between the second switching transistor Q2 and the fourth switching transistor Q4. The second end of the third switching transistor Q3 is also connected to the second end of the fourth switching transistor Q4. The second switching transistor Q2 includes a body diode D2.

[0025] In one embodiment of the present application, the power supply device may be a DC power supply device such as a solar power supply device, an energy storage device, or other power supply devices such as a bidirectional power supply, and the present application does not limit this. The external device may be an electrical device that receives electrical energy, such as a household appliance.

[0026] In one embodiment of the present application, the first switch tube Q1, the second switch tube Q2, the third switch tube Q3 and the fourth switch tube Q4 can be MOS tubes or triodes. Figure 1 The following description uses the example of the first switching transistor Q1, the second switching transistor Q2, the third switching transistor Q3, and the fourth switching transistor Q4 being triodes. For example, when the first switching transistor Q1 is a triode, the first terminal of the first switching transistor Q1 is the collector (C electrode), the second terminal is the emitter (E electrode), and the control terminal is the base (G electrode). The terminals of the second switching transistor Q2, the third switching transistor Q3, and the fourth switching transistor Q4 are the same as those of the first switching transistor Q1 and are not described again here.

[0027] like Figure 1As shown, the first switch transistor Q1 includes a first body diode D1, which is connected between the first and second ends of the first switch transistor Q1. The second switch transistor Q2 includes a second body diode D2, which is connected between the first and second ends of the second switch transistor Q2. The third switch transistor Q3 includes a third body diode D3, which is connected between the first and second ends of the third switch transistor Q3. The fourth switch transistor Q4 includes a fourth body diode D4, which is connected between the first and second ends of the fourth switch transistor Q4.

[0028] In one embodiment of the present application, the voltage conversion circuit 10 further includes a first filter circuit 11, a second filter circuit 12, a third filter circuit 13, and a fourth filter circuit 14. The first filter circuit 11 is connected between the second terminal and the control terminal of the first switch transistor Q1. The second filter circuit 12 is connected between the second terminal and the control terminal of the second switch transistor Q2. The third filter circuit 13 is connected between the second terminal and the control terminal of the third switch transistor Q3. The fourth filter circuit 14 is connected between the second terminal and the control terminal of the fourth switch transistor Q4.

[0029] In the embodiment of the present application, the circuit structures and functions of the first filter circuit 11, the second filter circuit 12, the third filter circuit 13 and the fourth filter circuit 14 are the same. The circuit structure and function of the first filter circuit 12 are specifically described below taking the first filter circuit 12 as an example. Figure 1 The first filter circuit 11 includes a first resistor R1, a second resistor R2, and a capacitor C. The first resistor R1 and the capacitor C are connected in series, and the second resistor R2 is connected in parallel with the first resistor R1 and the capacitor C. The first filter circuit 11 is used to filter the input voltage of the first switch tube Q1 to make the voltage more stable.

[0030] In one embodiment of the present application, the voltage conversion circuit 10 further includes a main control circuit (not shown). The main control circuit is connected to the control terminals of the first switch tube Q1, the second switch tube Q2, the third switch tube Q3, and the fourth switch tube Q4. For example, taking the first switch tube Q1 as an example, when the first switch tube Q1 is a triode, the main control circuit is connected to the G pole of the first switch tube Q1. The main control circuit is used to execute the control method of the voltage conversion circuit of the present application. In one embodiment of the present application, the main control circuit can be a chip. In one embodiment of the present application, the first switch tube Q1, the second switch tube Q2, the third switch tube Q3, and the fourth switch tube Q4 can be NPN-type triodes.

[0031] refer to Figure 2 FIG. 1 is a flow chart of a control method of a voltage conversion circuit 10 according to an embodiment of the present invention. The control method of the voltage conversion circuit includes the following steps.

[0032] Step S210 , obtaining a first duty cycle of the fourth switch tube and an input current flowing through the inductor.

[0033] In one embodiment of the present application, the main control circuit can obtain the duty cycle of each switch. For example, the main control circuit obtains the first duty cycle of the fourth switch Q4. In one embodiment of the present application, the first duty cycle can be preset or obtained through other means, which is not limited by the present application. In one embodiment of the present application, the main control circuit also includes a sampling circuit that can sample the input current flowing through the inductor L and transmit it to the main control circuit.

[0034] Step S220 , controlling the first switch tube to remain turned on and the third switch tube to remain turned off.

[0035] In one embodiment of the present application, the main control circuit controls the first switch Q1 to remain on and the third switch Q3 to remain off, so that the voltage conversion circuit 10 operates in a boost mode. In one embodiment of the present application, the main control circuit controls the first switch Q1 to be on by adjusting the voltage at the control terminal of the first switch Q1. For example, the main control circuit controls the first switch Q1 to be on by adjusting the voltage at the control terminal of the first switch Q1 to a high level. In one embodiment of the present application, the main control circuit controls the third switch Q3 to be off by adjusting the voltage at the control terminal of the third switch Q3. For example, the main control circuit controls the third switch Q3 to be off by adjusting the voltage at the control terminal of the third switch Q3 to a low level.

[0036] In another embodiment of the present application, when the first switch Q1 and the third switch Q3 of the voltage conversion circuit 10 are NPN transistors, the main control circuit sends a first pulse width modulation (PWM) signal to the first switch Q1 to control the first switch Q1 to remain on, wherein the duty cycle of the first PWM signal is 1. The main control circuit sends a second PWM signal to the third switch Q3 to control the third switch Q3 to remain off, wherein the duty cycle of the second PWM signal is 0.

[0037] Step S230 , when the input current is less than a first preset value, controlling the fourth switch tube to be turned on with a first duty cycle, and controlling the second switch tube to be turned off.

[0038] refer to Figure 3As shown, it is a schematic diagram of the input current and the conduction time of the fourth switch tube Q4 and the second switch tube Q2 in one embodiment of the present application. In one embodiment of the present application, after the first switch tube Q1 remains on and the third switch tube Q3 remains off, when the fourth switch tube Q4 is controlled to be turned on, the input current flowing through the inductor L gradually increases with time. When the input current is less than the first preset value, the main control circuit controls the fourth switch tube Q4 to be turned on with a first duty cycle, and controls the second switch tube Q2 to be turned off. In one embodiment of the present application, the main control circuit controls the second switch tube Q2 to be turned off by adjusting the voltage of the control end of the second switch tube Q2 to a low level. In one embodiment of the present application, the first preset value can be set according to user needs. For example, the first preset value can be set to 2 amperes. This application does not limit this. Reference Figure 3 , in the rising stage when the input current is less than the first preset value and gradually increases, since the input current is small and the second body diode D2 is connected between the first and second ends of the second switch tube Q2, Figure 3 During the time period from the first time point t1 to the second time point t2, the fourth switch Q4 is turned on, and the input current increases. During the time period from the second time point t2 to the third time point t3, the fourth switch Q4 is turned off, and the voltage conversion circuit 10 enters the asynchronous rectification stage. The corresponding input current is freewheeled through the second body diode D2 of the second switch Q2.

[0039] Step S240 , obtaining the required current of the external device and the dead time of the voltage conversion circuit.

[0040] In one embodiment of the present application, the demand current is the current required by the load connected to the voltage conversion circuit 10. For example, after the voltage conversion circuit 10 is connected to an external device serving as a load through the first voltage output terminal VOUT1 and the second voltage output terminal VOUT2, the demand current is the current required by the external device.

[0041] In one embodiment of the present application, the switching transistor of the voltage conversion circuit 10 is an insulated gate transistor (IGBT). In related art, since power devices such as IGBTs all have a certain amount of junction capacitance, this can cause delays in the device's turn-on and turn-off. The impact of this delay is minimized during module circuit design. For example, circuit designs to minimize this delay include increasing the drive voltage and current at the control terminal or providing a junction capacitance release loop. To ensure reliable IGBT operation and prevent the upper and lower bridge arms from being cutoff due to turn-off delay, it is necessary to set a dead time. The dead time is the time it takes for both the upper and lower bridge arms to be turned off simultaneously. This dead time effectively prevents delay effects that could cause one bridge arm to not fully turn off while the other is still on, thus preventing cut-through and module explosion. A larger dead time results in more reliable module operation, but it can also cause output waveform distortion and reduce output efficiency. A smaller dead time results in less distortion in the module's output waveform, but it can also reduce reliability. Dead time is typically in the microsecond range. Generally, dead time cannot be changed and depends solely on the power component manufacturing process. In related technologies, dead time is also used to refer to the time domain that cannot be controlled. For example, in inverters, dead time refers to the "0" zone of the power device's output voltage and current. In transmission control, dead time refers to the zero-crossing time of the motor's forward and reverse switching voltage and current. The optimal dead time setting principle is: while ensuring safety, the smaller the dead time, the better, to prevent the power tube from blowing up and the output from shorting out.

[0042] In one embodiment of the present application, the main control circuit obtains the dead time of the voltage conversion circuit 10. The dead time refers to the time when the second switch Q2 and the fourth switch Q4 are simultaneously off. The dead time of the voltage conversion circuit 10 is a standard value and a known constant. Therefore, the dead time of the voltage conversion circuit can be directly obtained.

[0043] Step S250 , calculating a second duty cycle of the second switch tube according to the first duty cycle, and updating the second duty cycle using the dead time to obtain a third duty cycle.

[0044] In one embodiment of the present application, the main control circuit uses the dead time to update the second duty cycle of the second switch tube Q2 to obtain a third duty cycle, while keeping the duty cycle of the fourth switch tube Q4 unchanged.

[0045] Step S260 , when the input current is greater than or equal to the first preset value and less than the required current, controlling the fourth switch tube to be turned on with the first duty cycle, and controlling the second switch tube to be turned on with the third duty cycle.

[0046] refer to Figure 3When the input current is greater than or equal to the first preset value and less than the required current, the main control circuit controls the fourth switch Q4 to conduct at the first duty cycle and controls the second switch Q2 to conduct at the third duty cycle. Because the second switch Q2 is conducted at the updated third duty cycle, the on-time of the second switch Q2 at the third duty cycle is reduced relative to the on-time of the second switch Q2 at the second duty cycle. Therefore, when the fourth switch Q4 switches from off to on, the second switch Q2 switches from on to off in advance by the dead time, thereby preventing the dead time from affecting the fourth switch Q4. This further prevents current jitter in the fourth switch Q4 caused by the dead time, thereby improving the stability and safety of the voltage conversion circuit 10.

[0047] For example, this application solves the problem of current jitter in the voltage boost stage in the related art. For details, refer to Figure 4 , in the rising stage when the input current is less than the first preset value and gradually increases, since the input current is small and the second body diode D2 is connected between the first and second ends of the second switch tube Q2, Figure 3 In the time period from the first time point t1 to the second time point t2 shown, the fourth switch tube Q4 is turned on, and the input current rises at this time. When in the time period from the second time point t2 to the third time t3, the fourth switch tube Q4 is disconnected, and the voltage conversion circuit 10 enters the asynchronous rectification stage, and the corresponding input current is continued through the second body diode D2 of the second switch tube Q2. When the input current exceeds the first preset value, the voltage conversion circuit 10 enters the synchronous rectification stage. At this time, since the input current is large, if the second body diode D2 is still used, it will cause the second body diode D2 to heat up and burn. Therefore, when the fourth switch tube Q4 is turned off, the second switch tube Q2 needs to be turned on and the second switch tube Q2 is used for continued current. However, in the process of alternating conduction of the fourth switch tube Q4 and the second switch tube Q2, a dead time occurs between the fourth switch tube Q4 and the second switch tube Q2, and the dead time will be compensated to the fourth switch tube Q4. For example, referring to Figure 4 The dead time compensation is applied to the on-time of the fourth switch Q4 from the fifth time point t5 to the sixth time point t6, which shortens the on-time of the fourth switch Q4. Since the current rises when the fourth switch Q4 is turned on, if the on-time of the fourth switch Q4 is shortened, the corresponding current will fluctuate. Figure 4 From the fifth time point t5 to the sixth time point t6, the current jitters, thus causing the input current to jitter, affecting the normal voltage boosting of the voltage conversion circuit 10 and affecting the safety of the circuit.

[0048] refer to Figure 3When performing a boost conversion, the voltage conversion circuit 10 of the present application obtains the first duty cycle of the fourth switch Q4 and the input current flowing through the inductor L. When the input current is less than a first preset value, the fourth switch Q4 is controlled to be turned on at the first duty cycle, and the second switch Q2 is controlled to be turned off. The required current of the external device and the dead time of the voltage conversion circuit are then obtained, and the second duty cycle of the second switch Q2 is updated using the dead time. For example, the dead time is compensated for the on-time of the second switch Q2 between the fourth time point t4 and the fifth time point t5 to obtain a third duty cycle. The fourth switch Q4 is then controlled to be turned on at the first duty cycle, for example, the fourth switch Q4 is controlled to be turned on from the fifth time point t5 to the sixth time point t6. Finally, the second switch Q2 is controlled to be turned on at the updated third duty cycle. The solution of the present application utilizes the dead time to update the second duty cycle of the second switch tube Q2, while keeping the duty cycle of the fourth switch tube Q4 unchanged. Therefore, the normal operation of the voltage conversion circuit 10 can be ensured while avoiding the influence of the dead time on the fourth switch tube Q4. In addition, the current jitter problem of the fourth switch tube Q4 caused by the influence of the dead time is avoided, thereby improving the stability and safety of the voltage conversion circuit 10. For example, referring to Figure 4 , the on-time of the fourth switch tube Q4 from the fourth time point t4 to the fifth time point t5 is 6.6us, and the dead time is 0.24us. After the dead time is compensated for the on-time of the fourth switch tube Q4 from the fourth time point t4 to the fifth time point t5, the on-time of the fourth switch tube Q4 is shortened to 6.6-0.24=6.36us. However, referring to Figure 3 The solution of the present application utilizes the dead time to update the second duty cycle of the second switch tube Q2 while keeping the duty cycle of the fourth switch tube Q4 unchanged, thereby avoiding the influence of the dead time on the fourth switch tube Q4. Therefore, the problem of current jitter of the fourth switch tube caused by the influence of the dead time is avoided, and the stability and safety of the voltage conversion circuit during the boost conversion are improved.

[0049] refer to Figure 5 As shown, it is a flow chart of obtaining the first duty cycle of the fourth switch tube in one embodiment of the present application, which specifically includes the following steps.

[0050] Step S510: obtaining the supply voltage of the power supply device and the required voltage of the external device.

[0051] In one embodiment of the present application, the main control circuit obtains the supply voltage input from the first voltage input terminal VIN1 and the second voltage input terminal VIN2. In one embodiment of the present application, the main control circuit can obtain the supply voltage input from the first voltage input terminal VIN1 and the second voltage input terminal VIN2 through a sampling circuit.

[0052] Step S520 : determining a first duty cycle of the fourth switch tube according to the power supply voltage of the power supply device and the required voltage of the external device.

[0053] In one embodiment of the present application, the main control circuit subtracts the supply voltage from the demand voltage to obtain a voltage difference, and then divides the voltage difference by the demand voltage to obtain a first duty cycle. Specifically, the main control circuit calculates the first duty cycle according to the formula dc1 = (v1 - v2) / v1, where v1 represents the demand voltage, v2 represents the supply voltage, and dc1 represents the first duty cycle. For example, if the demand voltage is 10V and the supply voltage is 4.5V, then according to the above formula, the first duty cycle can be calculated to be 0.55.

[0054] In this application, the main control circuit determines a first duty cycle according to the power supply voltage and the required voltage of the external device, and controls the fourth switch tube Q4 to be turned on according to the first duty cycle, so that the voltage conversion circuit 10 stably outputs the required voltage of the external device.

[0055] In one embodiment of the present application, after the input current is greater than or equal to a first preset value, the main control circuit controls the fourth switch Q4 and the second switch Q2 to alternately turn on and off according to a preset conversion cycle. The preset conversion cycle is the sum of the time it takes for the fourth switch Q4 to be turned on once and the time it takes for it to be turned off once. For example, within a preset conversion cycle, when the fourth switch Q4 is turned on, the second switch Q2 is turned off; and when the fourth switch Q4 is turned off, the second switch Q2 is turned on. Therefore, the sum of the first duty cycle of the fourth switch Q4 and the second duty cycle of the second switch Q2 is 1. The second duty cycle of the second switch Q2 is equal to 1 minus the first duty cycle of the fourth switch Q4. For example, if the first duty cycle is 0.55, the second duty cycle is 0.45.

[0056] After calculating the second duty cycle of the second switch Q2 , the main control circuit also uses the dead time to update the second duty cycle of the second switch Q2 to compensate for the dead time on the second switch Q2 , thereby preventing the dead time from affecting the fourth switch Q4 .

[0057] refer to Figure 6 As shown, it is a flow chart of using dead time to update the second duty cycle in one embodiment of the present application, which specifically includes the following steps.

[0058] Step S610: obtaining a preset conversion period of the voltage conversion circuit.

[0059] In one embodiment of the present application, the main control circuit uses the total time of the fourth switch Q4 being on once plus the time of the fourth switch Q4 being off once as the preset conversion period. For example, if the fourth switch Q4 is on once for 6.6 μs and off once for 5.4 μs, the total time of the on and off times is 12 μs. The main control circuit may use 12 μs as the preset conversion period.

[0060] Step S620: multiply the second duty cycle by the preset conversion period to obtain the planned on-time of the second switch tube.

[0061] In one embodiment of the present application, the main control circuit multiplies the second duty cycle by the preset conversion period of the fourth switch Q4 to obtain the product value as the planned on-time of the second switch Q2. For example, if the second duty cycle is 0.45 and the preset conversion period is 12 μs, the planned on-time of the second switch Q2 is 12*0.45=5.4 μs.

[0062] Step S630 : Subtract the dead time from the planned on-time to obtain the actual on-time.

[0063] In one embodiment of the present application, the main control circuit calculates the difference between the planned on-time of the second switch Q2 and the dead time to reduce the on-time of the second switch Q2. For example, if the dead time is 0.24 μs and the planned on-time of Q2 is 5.4 μs, the actual on-time of the second switch Q2 is 5.4 μs - 0.24 μs = 5.16 μs. Thus, the actual on-time of the second switch Q2 is reduced by 0.24 μs relative to the planned on-time of the second switch Q2.

[0064] Step S640: Divide the actual on-time by the preset conversion period to obtain a third duty cycle.

[0065] For example, the main control circuit divides the actual on-time of 5.16 μs by the preset conversion period of 12 μs to obtain a third duty cycle of 0.43. In one embodiment of the present application, the main control circuit uses the formula dc3 = (dc2 × Tt) / T, where dc2 represents the second duty cycle, T represents the preset conversion period, and dc3 represents the third duty cycle.

[0066] The main control circuit divides the actual on-time by the preset period to obtain a third duty cycle, which is reduced by the preset duty cycle relative to the second duty cycle; the preset duty cycle is the ratio of the dead time to the preset conversion period.

[0067] In one embodiment of the present application, the method for updating the second duty cycle using the dead time to obtain the third duty cycle further includes: obtaining a preset conversion period of the voltage conversion circuit 10; subtracting the dead time from the preset conversion period to obtain an actual conversion period; multiplying the first duty cycle by the preset conversion period to obtain an actual on-time of the fourth switch Q4; subtracting the actual on-time from the actual conversion period to obtain an actual on-time of the second switch Q2; and dividing the actual on-time of the second switch Q2 by the preset conversion period to obtain the third duty cycle. In one embodiment of the present application, the main control circuit calculates the third duty cycle according to the formula dc3 = ((Tt) - dc1 × T) / T, where T represents the preset conversion period, t represents the dead time, (Tt) represents the actual conversion period, represents the first duty cycle, dc1 × T represents the actual on-time of the fourth switch Q4, and ((Tt) - dc1 × T) represents the actual on-time of the second switch Q2. For example, if the preset conversion period of the voltage conversion circuit 10 is 12 us, the dead time is 0.24 us, and the first duty cycle is 0.55, then the main control circuit subtracts the dead time from the preset conversion period to obtain an actual conversion period of (12-0.24) = 11.76 us. The main control circuit multiplies the first duty cycle by the preset conversion period to obtain the actual on-time of the fourth switch Q4, which is 0.55×12 = 6.6 us. The main control circuit subtracts the actual on-time from the actual conversion period to obtain the actual on-time of the second switch Q2, which is (11.76-6.6) = 5.16 us. The main control circuit divides the actual on-time of the second switch Q2 by the preset conversion period to obtain a third duty cycle of dc3 = 5.16 / 12 = 0.43.

[0068] In one embodiment of the present application, the second duty cycle is updated using the dead time to obtain a third duty cycle, including: obtaining a preset conversion period of the voltage conversion circuit 10; dividing the dead time by the preset conversion period to obtain a dead period percentage; subtracting the dead period percentage from 1 and then subtracting the first duty cycle to obtain the third duty cycle. In one embodiment of the present application, the main control circuit calculates the third duty cycle according to the formula dc3 = (1-t / T-dc1), where T represents the preset conversion period, t represents the dead time, dc3 represents the third duty cycle, and dc1 represents the first duty cycle. For example, if the preset conversion period of the voltage conversion circuit 10 obtained by the main control circuit is 12us, and the dead time obtained is 0.24us, the first duty cycle obtained is 0.55. Then, the dead period percentage obtained by the main control circuit by dividing the dead time by the preset conversion period is 0.24 / 12 = 2%. The main control circuit subtracts the dead zone percentage from 1 and then subtracts the first duty cycle to obtain a third duty cycle of dc3 = 1-2% - 0.55 = 0.43.

[0069] refer to Figure 7FIG. 1 is a schematic diagram of a control device for a voltage conversion circuit according to an embodiment of the present application. The control device 70 for a voltage conversion circuit is applied to the voltage conversion circuit 10. Specifically, the control device 70 for a voltage conversion circuit includes a first acquisition module 701, a first switch control module 702, a second switch control module 703, a second acquisition module 704, a third switch control module 705, and a fourth switch control module 706.

[0070] The first acquisition module 701 is configured to acquire a first duty cycle of the fourth switch tube and an input current flowing through the inductor.

[0071] The first switch control module 702 is configured to control the first switch to remain on and the third switch to remain off.

[0072] The second switch control module 703 is configured to control the fourth switch tube to be turned on with a first duty cycle and control the second switch tube to be turned off when the input current is less than a first preset value.

[0073] The second acquisition module 704 is configured to acquire the required current of the external device and the dead time of the voltage conversion circuit.

[0074] The third switch control module 705 is configured to calculate a second duty cycle of the second switch according to the first duty cycle, and update the second duty cycle using the dead time to obtain a third duty cycle.

[0075] The fourth switch control module 706 is configured to control the fourth switch to be turned on with a first duty cycle and control the second switch to be turned on with a third duty cycle when the input current is greater than or equal to the first preset value and less than the required current.

[0076] It is understandable that the above Figure 7 The module division described is a logical functional division, and other division methods may be used in actual implementation. In addition, the functional modules in the various embodiments of this application can be integrated into the same processing unit, each module can be physically independent, or two or more modules can be integrated into the same unit. The above-mentioned integrated modules can be implemented in the form of hardware or hardware plus software functional modules.

[0077] refer to Figure 8 FIG2 is a schematic diagram of an electronic device provided in an embodiment of the present application. In one embodiment of the present application, the electronic device 80 includes, but is not limited to, a memory 802, a processor 803, and a computer program stored in the memory 802 and executable on the processor 803, such as a control program for a voltage conversion circuit.

[0078] The processor 803 may be a central processing unit (CPU), or other general-purpose processors, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor. The processor 803 is the computing core and control center of the electronic device 80. It utilizes various interfaces and lines to connect various parts of the entire electronic device 80 and obtain the operating system of the electronic device 80 as well as various installed applications, program codes, etc.

[0079] The processor 803 obtains the operating system of the electronic device 80 and various installed applications. The processor 803 obtains the application to implement the steps in the above-mentioned control method embodiments of each voltage conversion circuit, for example Figure 2 、 Figure 5 、 Figure 6 Steps in the embodiment.

[0080] The memory 802 can be used to store computer programs and / or modules. The processor 803 implements various functions of the electronic device 80 by running or accessing the computer programs and / or modules stored in the memory 802 and calling the data stored in the memory 802. The memory 802 may mainly include a program storage area and a data storage area. The program storage area may store an operating system and at least one application required for a function (such as a sound playback function, an image playback function, etc.); the data storage area may store data generated based on the use of the vehicle-mounted device. In addition, the memory 802 may include non-volatile memory, such as a hard disk, internal memory, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device.

[0081] The memory 802 may be an external memory and / or an internal memory of the electronic device 80. Furthermore, the memory 802 may be a physical memory, such as a memory stick, a TF card (Trans-flash Card), and the like.

[0082] If the program code and various data in the memory 802 are implemented in the form of a software functional unit and sold or used as an independent product, they can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, such as the channel method of the base station, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, it can implement the steps of the above-mentioned various method embodiments. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form, etc. The computer-readable medium may include: any entity or device that can carry computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), etc.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. A control method for a voltage conversion circuit, characterized in that: The voltage conversion circuit includes a first switching transistor, a second switching transistor, a third switching transistor, a fourth switching transistor, and an inductor. The first end of the first switching transistor is used to connect to a first voltage input terminal, the second end of the first switching transistor is connected to the first end of the third switching transistor, the second end of the third switching transistor is used to connect to a second voltage input terminal, the first end of the second switching transistor is used to connect to a first voltage output terminal, the second end of the second switching transistor is connected to the first end of the fourth switching transistor, and the second end of the fourth switching transistor is used to connect to a second voltage output terminal. The first voltage input terminal and the second voltage input terminal are used to connect to a power supply device, and the first voltage output terminal and the second voltage output terminal are used to connect to an external device. The first end of the inductor is connected between the first and third switching transistors, the second switching transistor includes a body diode, and the second end of the inductor is connected between the second and fourth switching transistors. The method includes: Obtaining a first duty cycle of the fourth switch tube and an input current flowing through the inductor; Controlling the first switch tube to remain on and the third switch tube to remain off; When the input current is less than a first preset value, controlling the fourth switch tube to be turned on with the first duty cycle, and controlling the second switch tube to be turned off; Obtaining a demand current of the external device and a dead time of the voltage conversion circuit; Calculating a second duty cycle of the second switch tube according to the first duty cycle, and updating the second duty cycle using the dead time to obtain a third duty cycle; When the input current is greater than or equal to the first preset value and less than the required current, the fourth switch tube is controlled to be turned on with the first duty cycle, and the second switch tube is controlled to be turned on with the third duty cycle.

2. The control method of the voltage conversion circuit according to claim 1, wherein: The obtaining of the first duty cycle of the fourth switch tube includes: Obtaining the supply voltage of the power supply device and the required voltage of the external device; The first duty cycle of the fourth switch is determined according to the power supply voltage of the power supply device and the required voltage of the external device.

3. The control method of the voltage conversion circuit according to claim 2, wherein: The determining the first duty cycle of the fourth switch tube according to the power supply voltage of the power supply device and the required voltage of the external device includes: Subtracting the supply voltage from the required voltage to obtain a voltage difference; The voltage difference is divided by the required voltage to obtain the first duty cycle.

4. The control method of the voltage conversion circuit according to claim 1, wherein: The calculating the second duty cycle of the second switch tube according to the first duty cycle includes: The second duty cycle is equal to 1 minus the first duty cycle.

5. The control method of the voltage conversion circuit according to claim 1, wherein: The updating the second duty cycle by using the dead time to obtain a third duty cycle includes: Obtaining a preset conversion period of the voltage conversion circuit; Multiplying the second duty cycle by a preset conversion period to obtain a planned on-time of the second switch tube; Subtracting the dead time from the planned on-time to obtain the actual on-time; The third duty cycle is obtained by dividing the actual on-time by the preset conversion period.

6. The control method of the voltage conversion circuit according to claim 1, wherein: The updating the second duty cycle by using the dead time to obtain a third duty cycle includes: Obtaining a preset conversion period of the voltage conversion circuit; Subtracting the dead time from the preset conversion period to obtain an actual conversion period; Multiplying the first duty cycle by a preset conversion period to obtain an actual on-time of the fourth switch tube; Subtracting the actual on-time from the actual conversion period to obtain the actual on-time of the second switch tube; The third duty cycle is obtained by dividing the actual on-time of the second switch tube by the preset conversion period.

7. The control method of the voltage conversion circuit according to claim 1, wherein: The updating the second duty cycle by using the dead time to obtain a third duty cycle includes: Obtaining a preset conversion period of the voltage conversion circuit; Dividing the dead time by the preset conversion period to obtain a dead percentage; The third duty cycle is obtained by subtracting the deadband percentage from 1 and then subtracting the first duty cycle.

8. A voltage conversion circuit, characterized in that: The voltage conversion circuit includes a main control circuit, a first switching transistor, a second switching transistor, a third switching transistor, a fourth switching transistor, and an inductor. The first end of the first switching transistor is used to connect to a first voltage input terminal, the second end of the first switching transistor is connected to the first end of the third switching transistor, the second end of the third switching transistor is used to connect to a second voltage input terminal, the first end of the second switching transistor is used to connect to a first voltage output terminal, the second end of the second switching transistor is connected to the first end of the fourth switching transistor, and the second end of the fourth switching transistor is used to connect to a second voltage output terminal. The first voltage input terminal and the second voltage input terminal are used to connect to a power supply device, and the first voltage output terminal and the second voltage output terminal are used to connect to an external device. The first end of the inductor is connected between the first and third switching transistors, the second switching transistor includes a body diode, and the second end of the inductor is connected between the second and fourth switching transistors. The main control circuit is connected to the control ends of the first switch tube, the second switch tube, the third switch tube and the fourth switch tube, and is used to execute the control method of the voltage conversion circuit according to any one of claims 1 to 7.

9. An electronic device, characterized in that: include: Battery modules; According to the voltage conversion circuit as claimed in claim 8, the battery module is connected to the first voltage output terminal and the second voltage output terminal.

10. A computer storage medium, characterized in that The computer storage medium stores program instructions, and when the program instructions are executed on the energy storage device, the energy storage device executes the control method for the voltage conversion circuit according to any one of claims 1 to 7.

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