H-bridge circuit control method, electronic equipment and switching power supply

Abstract

The embodiment of the invention discloses an H-bridge circuit control method, electronic equipment and a switching power supply. For an H-bridge circuit comprising a first switching tube group and a second switching tube group, the control method comprises the following steps: setting a target state and a target voltage of the H-bridge circuit; obtaining a duty ratio according to the output voltage and the target voltage; performing PWM modulation on the first switching tube group according to the duty ratio, the target state and the target voltage; and according to the target state and the target voltage, the second switching tube group is controlled to maintain a corresponding on or off state, so that the charging and discharging state of the H-bridge circuit reaches the target state, and the output voltage reaches the target voltage. By means of the mode, flexible switching between the BUCK mode and the BOOST mode can be achieved under the same H-bridge circuit topology, the defect of unipolar output is overcome, random combination of positive and negative bipolar voltage output and charging and discharging states is achieved, and the application scene and the use scheme of the H-bridge circuit are expanded.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of switching power supplies, and in particular to an H-bridge circuit control method, electronic equipment, and a switching power supply. Background Art

[0002] In the field of power electronics, DC-DC converters are core components for achieving DC voltage conversion and are widely used in various electronic devices and systems. Currently, the three most common DC-DC topologies used in switching power supplies are buck (step-down), boost (step-up), and buck-boost (step-down-boost).

[0003] A buck circuit can achieve a step-down function, where the output voltage is lower than the input voltage, and its output voltage maintains the same polarity as the input voltage. A boost circuit can achieve a step-up function, where the output voltage is higher than the input voltage, and similarly, its output voltage maintains the same polarity as the input voltage. A buck-boost circuit can achieve either step-up or step-down functions, but its output voltage has the opposite polarity to the input voltage.

[0004] However, existing technologies suffer from the following drawbacks: Whether using a buck circuit, a boost circuit, or a buck-boost circuit, they can only achieve unipolar voltage output. Specifically, the output voltage of a buck circuit and a boost circuit always maintains the same polarity as the input voltage; while a buck-boost circuit, while having an output voltage with the opposite polarity to the input voltage, still only outputs a single polarity voltage. This limitation prevents traditional DC-DC converters from achieving both positive and negative bipolar voltage outputs within the same circuit topology, restricting their use in applications requiring a bipolar power supply. Summary of the Invention

[0005] The main technical problem solved by the embodiments of the present invention is to provide an H-bridge circuit control method, an electronic device and a switching power supply, which can solve at least some of the defects of the existing switching power supplies.

[0006] In a first aspect, an embodiment of the present invention provides an H-bridge circuit control method, wherein the H-bridge circuit includes a first switch tube group and a second switch tube group, and includes the following steps: setting a target state and a target voltage of the H-bridge circuit; obtaining a duty cycle based on the output voltage and the target voltage; performing PWM modulation on the first switch tube group based on the duty cycle, the target state, and the target voltage; and controlling the second switch tube group to maintain a corresponding on or off state based on the target state and the target voltage, so that the charging and discharging state of the H-bridge circuit reaches the target state and the output voltage reaches the target voltage.

[0007] Optionally, obtaining the duty cycle based on the output voltage and the target voltage includes the following steps: calculating the duty cycle through dual closed-loop control based on the output voltage and the target voltage; the dual closed-loop control includes a voltage outer loop with the output voltage and the target voltage as input, and a current inner loop with the output of the voltage outer loop as input.

[0008] Optionally, the duty cycle is calculated through dual closed-loop control based on the output voltage and the target voltage, including the following steps: inputting the difference between the output voltage and the target voltage as an error signal into a first PI controller to obtain a voltage loop output; limiting the voltage loop output; and inputting the limited voltage loop output as an input to a second PI controller to obtain the duty cycle.

[0009] Optionally, the first switch tube group includes a first upper-arm switch tube S1 and a first lower-arm switch tube S2, and the PWM modulation of the first switch tube group according to the duty cycle, the target state, and the target voltage includes the following steps: when the target state is set to a discharge state and the polarity of the target voltage is positive, the first upper-arm switch tube S1 acts as a buck tube, and the on-time of the first upper-arm switch tube S1 is controlled according to the duty cycle to output the target voltage; when the target state is set to a discharge state and the polarity of the target voltage is negative, the first lower-arm switch tube S2 acts as a buck tube, and the on-time of the first lower-arm switch tube S2 is controlled according to the duty cycle to output the target voltage.

[0010] Optionally, the PWM modulation of the first switch tube group according to the duty cycle, the target state and the target voltage also includes the following steps: when the target state is set to the charging state and the polarity of the target voltage is positive, the first lower bridge arm switch tube S2 is used as a BOOST tube, and the conduction time of the first lower bridge arm switch tube S2 is controlled according to the duty cycle, and the first upper bridge arm switch tube S1 is controlled to be a freewheeling tube; when the target state is set to the charging state and the polarity of the target voltage is negative, the first upper bridge arm switch tube S1 is used as a BOOST tube, and the conduction time of the first upper bridge arm switch tube S1 is controlled according to the duty cycle, and the first lower bridge arm switch tube S2 is controlled to be a freewheeling tube.

[0011] Optionally, the BOOST transistor or the BUCK transistor is turned on before the freewheeling transistor.

[0012] Optionally, the second switch tube group includes a second upper-arm switch tube S3 and a second lower-arm switch tube S4, and controlling the second switch tube group to maintain a corresponding on-state or off-state according to the target state and the target voltage includes the following steps: when the target state is set to a discharge state and the polarity of the target voltage is positive, controlling the second upper-arm switch tube S3 to remain off and controlling the second lower-arm switch tube S4 to remain on; when the target state is set to a discharge state and the polarity of the target voltage is negative, controlling the second lower-arm switch tube S4 to remain off and controlling the second upper-arm switch tube S3 to remain on.

[0013] Optionally, controlling the second switch tube group to maintain a corresponding on or off state according to the target state and the target voltage also includes the following steps: when the target state is set to a charging state and the polarity of the target voltage is positive, controlling the second upper arm switch tube S3 to remain off and controlling the second lower arm switch tube S4 to remain on; when the target state is set to a charging state and the polarity of the target voltage is negative, controlling the second lower arm switch tube S4 to remain off and controlling the second upper arm switch tube S3 to remain on.

[0014] In a second aspect, an embodiment of the present invention provides an electronic device, comprising: at least one processor; at least one network interface, the network interface being communicatively connected to the corresponding processor; and a memory being communicatively connected to the at least one processor; wherein the network interface is used to establish a communication connection between the processor and other external devices; the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor so that the at least one processor can execute the H-bridge circuit control method as described in the first aspect.

[0015] In a third aspect, an embodiment of the present invention provides a switching power supply, comprising: an H-bridge circuit; and the electronic device as described in the second aspect.

[0016] The beneficial effects of the embodiments of the present invention are as follows: unlike the prior art, the embodiments of the present invention can realize flexible switching between BUCK mode and BOOST mode under the same H-bridge circuit topology, overcome the defects of unipolar output, realize random combination of positive and negative bipolar voltage output and charge and discharge states, and expand the application scenarios and usage schemes of the H-bridge circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] One or more embodiments are exemplarily illustrated by corresponding drawings, which do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0018] Figure 1 It is a structural diagram of the Buck circuit in the prior art; Figure 2 It is a structural diagram of a Boost circuit in the prior art; Figure 3 It is a structural diagram of a Buck-Boost circuit in the prior art; Figure 4 It is a structural diagram of the H-bridge circuit; Figure 5 1 is a flow chart of an H-bridge circuit control method provided by an embodiment of the present invention; Figure 6 It is the control block diagram for calculating duty cycle; Figure 7 The figure shows the current loop when the H-bridge circuit is set to discharge state and the polarity of the target voltage is positive and the BUCK tube is turned on. Figure 8 The figure shows the current loop of the freewheeling diode when the H-bridge circuit is set to the discharge state and the polarity of the target voltage is positive; Figure 9 The figure shows the current loop when the H-bridge circuit is set to discharge state and the polarity of the target voltage is negative and the buck tube is conducting. Figure 10 The figure shows the current loop of the freewheeling diode when the H-bridge circuit is set to the discharge state and the polarity of the target voltage is negative; Figure 11 The figure shows the current loop when the H-bridge circuit is set to charging state and the polarity of the target voltage is positive and the BOOST tube is turned on. Figure 12 The figure shows the current loop when the H-bridge circuit is set to the charging state and the polarity of the target voltage is positive and the freewheeling diode is turned on; Figure 13 The figure shows the current loop when the H-bridge circuit is set to charging state and the polarity of the target voltage is negative and the BOOST tube is turned on. Figure 14 The figure shows the current loop of the freewheeling diode when the H-bridge circuit is set to the charging state and the polarity of the target voltage is negative; Figure 15 It is a structural diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0019] In order to facilitate the understanding of the present application, the present application is described in more detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that when an element is described as being "fixed to" another element, it can be directly on the other element, or there can be one or more centered elements therebetween. When an element is described as being "connected to" another element, it can be directly connected to the other element, or there can be one or more centered elements therebetween. The terms "upper", "lower", "inner", "outer", "bottom" and the like used in this specification indicate an orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" and the like are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0020] Unless otherwise defined, all technical and scientific terms used in this specification have the same meanings as those commonly understood by those skilled in the art to which this application belongs. The terms used in this specification and in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" as used in this specification includes any and all combinations of one or more of the relevant listed items.

[0021] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0022] The technical solution in this application will be described below with reference to the accompanying drawings.

[0023] In the field of power electronics, three basic DC-DC topologies are widely used in switching power supplies. As examples and not limitations, Figure 1 The Buck circuit shown can achieve the step-down function, and the output voltage is lower than the input voltage and maintains the same polarity as the input voltage; Figure 2 The Boost circuit shown can achieve the boost function, and the output voltage is higher than the input voltage and maintains the same polarity as the input voltage; Figure 3 The Buck-Boost circuit shown can achieve both step-up and step-down functions, but the output voltage has the opposite polarity to the input voltage.

[0024] These existing traditional topologies have significant technical drawbacks. Specifically, Buck, Boost, and Buck-Boost circuits can only achieve unipolar voltage outputs and cannot flexibly generate positive or negative output voltages according to application requirements. Understandably, when certain applications require both positive and negative voltage outputs, traditional single topologies cannot meet the technical requirements of bipolar outputs.

[0025] By way of example and not limitation, applications such as motor drive, battery charge and discharge management, and bidirectional power conversion often require a power supply system that can flexibly control the output voltage polarity. Specifically, motor forward and reverse control requires bidirectional positive and negative voltage drive, and battery systems require both charging and discharging modes.

[0026] By way of example and not limitation, Figure 4 The H-bridge circuit shown includes a DC power supply DC, switches S1, S2, S3, S4, an inductor L, a capacitor C, and a load R. Specifically, switches S1 and S3 form the upper arm, switches S2 and S4 form the lower arm, inductor L is connected between the two midpoints of the H-bridge circuit, and capacitor C and load R are connected in parallel at the output end of the circuit. As a classic circuit topology, the H-bridge circuit, although structurally equipped with the hardware foundation for achieving bipolar output, is primarily used in the prior art as a full-bridge inverter circuit to implement DC-AC conversion, converting DC power into AC power. It is not difficult to understand that traditional H-bridge applications have not fully realized their potential in the field of DC-DC conversion, particularly in achieving adjustable positive and negative voltage outputs.

[0027] As an example, not a limitation, existing H-bridge inverter applications typically generate AC output by alternating diagonal switches. However, they lack specialized control strategies for achieving adjustable positive and negative voltage outputs in DC-DC conversion. Specifically, key technical challenges remain, such as how to properly allocate the operating modes of the four switches, how to flexibly switch between charging and discharging states, and how to ensure circuit stability with varying polarity outputs.

[0028] Based on the above problems, the embodiment of the present invention provides an H-bridge circuit control method, the flow chart of which is as follows: Figure 5 As shown, the specific steps include: S100: Set the target state and target voltage of the H-bridge circuit In some embodiments of the present application, the control system first determines the operating target of the H-bridge circuit. Specifically, the operating target includes a target state and a target voltage. The target state includes two operating modes: charging state and discharging state. The target voltage includes two parameters: voltage amplitude and voltage polarity. It is easy to understand that the charging state corresponds to the operating characteristics of the boost circuit, and the discharging state corresponds to the operating characteristics of the buck circuit.

[0029] By way of example and not limitation, when the H-bridge circuit is used to charge a battery, the control system sets the target state to the charging state and simultaneously sets the target voltage amplitude corresponding to the rated battery voltage. When the H-bridge circuit is used to power a load, the control system sets the target state to the discharging state, and the target voltage polarity can be set to positive or negative based on the load characteristics.

[0030] S200: Obtain duty cycle based on output voltage and target voltage In some embodiments of the present application, the control system uses a closed-loop control algorithm to calculate the duty cycle required for PWM modulation based on the output voltage and the target voltage. Specifically, a dual closed-loop control structure is adopted, with the outer loop being the voltage loop and the inner loop being the current loop, to ensure that the output voltage accurately tracks the target voltage.

[0031] S300: Perform PWM modulation on the first switch group according to the duty cycle, target state and target voltage In some embodiments of the present application, the first switching transistor group includes a first upper-arm switching transistor S1 and a first lower-arm switching transistor S2. This step performs differential PWM modulation on the first upper-arm switching transistor S1 and the first lower-arm switching transistor S2 based on the aforementioned parameters. Specifically, the first upper-arm switching transistor S1 and the first lower-arm switching transistor S2 utilize a complementary high-frequency switching mode, with one serving as the main power switch and the other as the freewheeling switch.

[0032] Specifically, when the target state is the discharge state and the target voltage polarity is positive, the first upper-arm switch tube S1 acts as a Buck tube to control the on-time according to the duty cycle, and the first lower-arm switch tube S2 acts as a freewheeling tube to provide a freewheeling path for the inductor current. When the target state is the discharge state and the target voltage polarity is negative, the first lower-arm switch tube S2 acts as a Buck tube to control the on-time according to the duty cycle, and the first upper-arm switch tube S1 acts as a freewheeling tube to provide a freewheeling path for the inductor current. When the target state is the charge state and the target voltage polarity is positive, the first lower-arm switch tube S2 acts as a Boost tube to control the on-time according to the duty cycle, and the first upper-arm switch tube S1 acts as a freewheeling tube to cooperate with the inductor energy storage and release process. When the target state is the charge state and the target voltage polarity is negative, the first upper-arm switch tube S1 acts as a Boost tube to control the on-time according to the duty cycle, and the first lower-arm switch tube S2 acts as a freewheeling tube to cooperate with the inductor energy storage and release process.

[0033] The on-time of the main power switch is directly determined by the duty cycle. A higher duty cycle results in a longer on-time and higher output power. The freewheeling switch, which turns on during the main power switch's off period, provides a continuous flow path for the inductor current, preventing voltage spikes caused by sudden changes in the inductor current.

[0034] S400: According to the target state and target voltage, control the second switch tube group to maintain the corresponding on or off state, so that the charge and discharge state of the H-bridge circuit reaches the target state and the output voltage reaches the target voltage In some embodiments of the present application, the second switch tube group includes a second upper arm switch tube S3 and a second lower arm switch tube S4. The second upper arm switch tube S3 and the second lower arm switch tube S4 are set to a long-term on or off state without high-frequency switching.

[0035] Specifically, when the target voltage polarity is positive, regardless of whether the device is in the charging or discharging state, the second upper-arm switch S3 is kept off and the second lower-arm switch S4 is kept on, allowing current to flow from the top to the bottom of the H-bridge. By way of example and not limitation, when the target voltage polarity is negative, the second lower-arm switch S4 is kept off and the second upper-arm switch S3 is kept on, reversing the current flow direction and generating a voltage opposite to the positive polarity across the load.

[0036] In some embodiments of the present application, step S200 specifically includes the following steps: Step S210: Calculate the duty cycle through dual closed-loop control according to the output voltage and the target voltage.

[0037] In some embodiments of the present application, a dual closed-loop control structure includes two control loops: an outer voltage loop and an inner current loop. Specifically, the outer voltage loop takes the output voltage Vout and the target voltage Vref as inputs and is responsible for ensuring that the output voltage accurately tracks the target voltage. The inner current loop takes the output of the outer voltage loop as input and is responsible for providing fast dynamic response and good current regulation performance.

[0038] In some embodiments of the present application, step S210 specifically includes the following steps: Step S211: inputting the difference between the output voltage and the target voltage as an error signal into the first PI controller to obtain a voltage loop output.

[0039] In some embodiments of the present application, the control system first uses the difference between the output voltage Vout and the target voltage Vref as an error signal. Specifically, the error signal e = Vref - Vout is input to a first PI controller, which processes the error signal using a proportional-integral algorithm to obtain a voltage loop output.

[0040] The proportional component of the first PI controller can quickly respond to changes in voltage error, while the integral component can eliminate the system's steady-state error. By way of example and not limitation, when the output voltage is below the target voltage, the error signal is positive, and the first PI controller outputs a positive regulation signal, indicating that the system needs to increase power transfer. When the output voltage is above the target voltage, the error signal is negative, and the first PI controller outputs a negative regulation signal, indicating that the system needs to decrease power transfer.

[0041] Specifically, the transfer function of the first PI controller can be expressed as Kp1+Ki1 / s, where Kp1 is a proportional coefficient and Ki1 is an integral coefficient.

[0042] Step S212: limiting the voltage loop output.

[0043] In some embodiments of the present application, the output of the first PI controller is subject to amplitude limiting to prevent excessive control signals from causing system instability or hardware damage. Specifically, the amplitude limiting process limits the voltage loop output to between preset upper and lower limits, ensuring that the subsequent current loop input signal remains within a reasonable range.

[0044] As an example, and not a limitation, during system startup or sudden load changes, the voltage error may be large, and the output of the first PI controller may exceed the normal operating range. In this case, the limiter can promptly constrain the control signal to prevent overshoot or oscillation in the system. Specifically, the upper limiter is typically determined based on the maximum allowable inductor current, while the lower limiter takes into account the minimum operating current requirement of the circuit.

[0045] Step S213: the voltage loop output after limiting is input to the second PI controller to obtain a duty cycle.

[0046] In some embodiments of the present application, the limited voltage loop output serves as the input signal to a second PI controller, which generates the final duty cycle (Duty) based on a current regulation algorithm. Specifically, the second PI controller forms the inner current loop of the dual closed-loop control structure, and its output directly affects the PWM modulation of the first switch group in the H-bridge circuit.

[0047] As an example and not a limitation, a larger proportional coefficient Kp2 can improve the response speed of the system, but too large a value may cause system instability; an appropriate integral coefficient Ki2 can improve the steady-state performance of the system, but improper setting may cause integral saturation problems.

[0048] Specifically, the output duty cycle of the second PI controller typically ranges from 0 to 1, corresponding to the ratio of the switch's on-time to the switching period. When the Duty value is large, the switch's on-time is long, delivering more power to the load; when the Duty value is small, the switch's on-time is short, delivering less power to the load.

[0049] In some embodiments of the present application, step S300 specifically includes the following steps: Step S310: When the target state is set to the discharge state and the polarity of the target voltage is positive, the first upper arm switch tube S1 acts as a buck tube, controls the on-time of the first upper arm switch tube S1 according to the duty cycle, and controls the first lower arm switch tube S2 as a freewheeling tube.

[0050] Specifically, if Figure 7 As shown, when the first upper arm switch tube S1 is turned on, the current starts from the positive electrode of the DC power supply DC, passes through the first upper arm switch tube S1 and the inductor L, and flows to the load R. The inductor L stores magnetic energy in this process, and the inductor current shows a linear growth trend.

[0051] It's easy to understand that the first high-side switch S1, acting as a buck transistor and serving as the main power switch, has its on-time directly determined by the duty cycle. By way of example and not limitation, when the first high-side switch S1 is on, the current in the inductor increases linearly. Simultaneously, the inductor experiences self-induction, hindering the rapid rise of current. The inductor converts the input electrical energy into magnetic energy for storage.

[0052] For example Figure 8As shown, when the first upper-arm switch S1 turns off, the first lower-arm switch S2 immediately turns on as a freewheeling transistor, providing a continuous flow path for the inductor current. Because the inductor current cannot suddenly drop to zero, the inductor begins to release previously stored magnetic energy. This current flows through the first lower-arm switch S2 and the load R, forming a freewheeling loop, gradually reducing the inductor current. By alternating between the first upper-arm switch S1 and the first lower-arm switch S2, a step-down output is achieved, achieving an output voltage lower than the input voltage while maintaining positive polarity.

[0053] As a Buck transistor, the first upper-arm switch S1 must be turned on before the freewheeling transistor S2. Specifically, at the beginning of each PWM switching cycle, the control system first turns on the first upper-arm switch S1, establishing a current path from the DC power supply through the first upper-arm switch S1, the inductor L, and the load R. It then controls the conduction of the freewheeling transistor S2. If the freewheeling transistor S2 turns on before the Buck transistor S1, it may cause a sharp change in the voltage across the inductor, resulting in excessive di / dt and dangerous inrush current. This not only affects system stability but can also damage the switch and other circuit components.

[0054] Specifically, the on-time of Buck diode S1 is strictly controlled by the duty cycle, which must change slowly and gradually rather than suddenly. When the system starts up or switches operating modes, the duty cycle gradually increases from the initial value to the target value, ensuring a smooth increase in the inductor current and preventing adverse effects of sudden surges on the circuit.

[0055] Step S320: When the target state is set to the discharge state and the polarity of the target voltage is negative, the first lower bridge arm switch tube S2 acts as a buck tube, and the conduction time of the first lower bridge arm switch tube S2 is controlled according to the duty cycle, and the first upper bridge arm switch tube S1 is controlled to act as a freewheeling tube.

[0056] Specifically, if Figure 9 As shown, when the first lower bridge arm switch tube S2 is turned on, the current flows from the second upper bridge arm switch tube S3 through the inductor L to the load R, and then forms a loop through the first lower bridge arm switch tube S2. At this time, the current direction is opposite to that in step S310, and a negative polarity voltage output is generated at both ends of the load.

[0057] It's easy to understand that when the first lower-arm switch S2 functions as a Buck transistor, its operating principle is similar to that of the first upper-arm switch S1 in step S310, but the current flow direction is fundamentally different. By way of example and not limitation, when the first lower-arm switch S2 is on, the current in the inductor flows from the second upper-arm switch S3 to the first lower-arm switch S2. The inductor stores magnetic energy, causing the inductor current to increase linearly. Self-induction also hinders the rapid rise of current.

[0058] For example Figure 10 As shown in the figure, when the first lower-arm switch S2 is turned off, the first upper-arm switch S1 is turned on as a freewheeling transistor. The inductor releases the stored magnetic energy, and the current flows through the first upper-arm switch S1, the load R, and the second upper-arm switch S3 to form a freewheeling loop. Because the current direction is opposite to the positive polarity output, the voltage polarity across the load is also reversed, achieving a negative polarity step-down output.

[0059] The first lower-arm switch S2, acting as a buck transistor, must also be turned on before the freewheeling transistor S1. Specifically, the control system first turns on the first lower-arm switch S2 at the beginning of each switching cycle, establishing a negative current path. Freewheeling transistor S1 then turns on after the first lower-arm switch S2 turns off, providing a freewheeling path for the inductor current. The priority of turning on the buck transistor S2 ensures a smooth buildup of negative inductor current, preventing electromagnetic interference and voltage oscillations that could be caused by sudden changes in current direction.

[0060] In this mode, gradual duty cycle adjustment is particularly important because negative polarity output involves a complete reversal of current direction. A slow duty cycle change is required to achieve a smooth current transition and prevent excessive transient current from occurring during the positive and negative polarity switching process.

[0061] Step S330: When the target state is set to the charging state and the polarity of the target voltage is positive, the first lower bridge arm switch tube S2 is used as a BOOST tube, and the conduction time of the first lower bridge arm switch tube S2 is controlled according to the duty cycle, and the first upper bridge arm switch tube S1 is controlled to be a freewheeling tube.

[0062] Specifically, if Figure 11 As shown in the figure, when the first lower bridge arm switch tube S2 is turned on, the inductor is directly connected to the DC power supply (DC2) on the right. The current in the inductor increases linearly. The inductor's self-inductance hinders the current from rising. The inductor converts electrical energy into magnetic energy and stores it. At this time, the energy is mainly provided by capacitor C.

[0063] It's easy to understand that the operating principles of a boost circuit differ significantly from those of a buck circuit. As an example, and not a limitation, during the inductor energy storage phase when the first lower-arm switch S2 is on, DC power source DC2 doesn't directly charge DC power source DC1. Instead, it first charges inductor L, causing the inductor current to continue increasing, preparing for the subsequent energy release phase.

[0064] For example Figure 12 As shown, when the first lower-arm switch S2 turns off, the first upper-arm switch S1 turns on as a freewheeling transistor, and the inductor begins to release stored magnetic energy. At this point, the DC power supply DC and the inductor L simultaneously supply power to the load R, achieving a boosted output voltage that exceeds the input voltage. Due to the combined power supply of the DC power supply and the inductor, the output voltage can exceed the input voltage while maintaining positive polarity.

[0065] Specifically, Boost transistor S2 is first turned on to establish the inductor energy storage loop, and the inductor current increases linearly from zero. When the inductor has stored enough energy, Boost transistor S2 is turned off, and freewheeling transistor S1 is immediately turned on, releasing the inductor's energy and boosting the output voltage. If the S1 freewheeling transistor is turned on before the S2 Boost transistor has completed energy storage, the inductor will not store enough energy, and the boost function will not be able to be effectively achieved. It may also cause a DC power supply short circuit or inductor current loss of control.

[0066] Specifically, the on-time of the S2 Boost tube needs to be precisely controlled. If the on-time is too short, the inductor energy storage will be insufficient and the boost effect will be poor. If the on-time is too long, the inductor current may be too large, exceeding the safe operating range.

[0067] Step S340: When the target state is set to the charging state and the polarity of the target voltage is negative, the first upper arm switch tube S1 acts as a BOOST tube, controls the on-time of the first upper arm switch tube S1 according to the duty cycle, and controls the first lower arm switch tube S2 as a freewheeling tube.

[0068] Specifically, if Figure 13 As shown, when the first upper arm switch S1 is turned on, the current in the inductor increases linearly. The self-inductance of the inductor hinders the current from rising. The inductor converts electrical energy into magnetic energy and stores it. The current direction is opposite to that in step S330.

[0069] It's easy to understand that the inductor energy storage process in this operating mode is similar to step S330, but the current flows in the opposite direction. By way of example and not limitation, while the first upper-arm switch S1 is on, the inductor stores energy by connecting to the DC power supply DC2, preparing for the subsequent negative-polarity boost output.

[0070] For example Figure 14 As shown, when the first upper-arm switch S1 is turned off, the first lower-arm switch S2 is turned on as a freewheeling transistor, allowing the inductor to release stored magnetic energy. At this point, the DC power supply DC and the inductor L simultaneously supply power to the load R. However, because the current direction is opposite to that in step S330, a negative boost output is generated across the load, achieving a boost conversion function in which the output voltage is higher than the input voltage and has a negative polarity.

[0071] Specifically, Boost transistor S1 is turned on first to store energy in the inductor, establishing a negative inductor current. Freewheeling transistor S2 is turned on after Boost transistor S1 is turned off, collaborating with the inductor to complete the negative boost energy release process. The priority turn-on of S1 Boost transistor ensures not only sufficient inductor energy storage but also a smooth negative current buildup, avoiding current surges and voltage overshoots during the positive-negative polarity transition.

[0072] In some embodiments of the present application, step S400 specifically includes the following steps: Step S410: when the target state is set to the discharge state and the polarity of the target voltage is positive, the second upper bridge arm switch tube S3 is controlled to remain turned off, and the second lower bridge arm switch tube S4 is controlled to remain turned on.

[0073] Specifically, if Figure 7 and Figure 8 As shown, the second upper arm switch tube S3 remains in the off state for a long time, and the second lower arm switch tube S4 remains in the on state for a long time, cooperating with the PWM modulation of the first switch tube group S1 and S2 to achieve the forward step-down output of the Buck circuit.

[0074] It's easy to understand that the state of the second switch group directly determines the current flow path in the H-bridge circuit. By way of example and not limitation, when the second upper-arm switch S3 is off and the second lower-arm switch S4 is on, current can only flow from the top to the bottom of the H-bridge circuit, from the first upper-arm switch S1 through the inductor L to the load R, and then through the second lower-arm switch S4 back to the negative terminal of the circuit, forming a positive current loop.

[0075] Specifically, when Buck transistor S1 is on, the current path is: DC power supply positive electrode → S1 → inductor L → load R → S4 → DC power supply negative electrode. When freewheeling transistor S2 is on, the current path is: S2 → inductor L → load R → S4 → S2, forming a closed freewheeling loop. The off state of the second upper-arm switch S3 ensures that the current does not flow through the right path of the upper arm. The on state of the second lower-arm switch S4 provides a stable lower-arm return path for the current, generating a positive voltage across the load.

[0076] Step S420: when the target state is set to the discharge state and the polarity of the target voltage is negative, the second lower bridge arm switch tube S4 is controlled to remain turned off, and the second upper bridge arm switch tube S3 is controlled to remain turned on.

[0077] Specifically, if Figure 9 and Figure 10 As shown, the second lower bridge arm switch tube S4 remains in the off state, and the second upper bridge arm switch tube S3 remains in the on state, cooperating with the PWM modulation of the first switch tube group, and the current direction is completely opposite to that in step S410.

[0078] It's easy to understand that by changing the conduction state of the second switch group, flexible switching of current polarity can be achieved. By way of example and not limitation, when the second lower-arm switch S4 is off and the second upper-arm switch S3 is on, current is forced to flow from the bottom to the top of the H-bridge circuit, i.e., from the second upper-arm switch S3 through the inductor L to the load R, and then back through the corresponding switch, forming a negative current loop.

[0079] Specifically, when the Buck transistor S2 is on, the current path is: DC power supply positive electrode → S3 → load R → inductor L → S2 → DC power supply negative electrode; when the freewheeling transistor S1 is on, the current path is: S3 → load R → inductor L → S1. Because the current direction is opposite to the positive polarity mode, the voltage polarity across the load is also reversed, achieving a negative-polarity Buck step-down output. The off state of the second lower-arm switch S4 blocks the current path in the lower arm, while the on state of S3 provides a path for reverse current to flow in the upper arm.

[0080] Step S430: when the target state is set to the charging state and the polarity of the target voltage is positive, the second upper bridge arm switch tube S3 is controlled to remain turned off, and the second lower bridge arm switch tube S4 is controlled to remain turned on.

[0081] Specifically, if Figure 11 and Figure 12 As shown, the second upper bridge arm switch tube S3 is turned off and the second lower bridge arm switch tube S4 is turned on, cooperating with the first switch tube group to realize the forward boost output function of the Boost circuit.

[0082] It's easy to understand that the state settings of the second switch group remain consistent when outputting the same polarity in both the charging and discharging states. As an example and not a limitation, whether in Buck or Boost mode, as long as positive polarity output is required, the second upper-arm switch S3 remains off and the second lower-arm switch S4 remains on, ensuring consistent current flow.

[0083] Specifically, in the energy storage stage when the Boost tube S2 is turned on, Figure 11 , the current path is mainly: DC power supply DC2 positive pole → inductor L → S2 → S4 → DC power supply DC2 negative pole. Figure 12 In the energy release stage when the freewheeling tube S1 is turned on, the current path is: capacitor C → inductor L → S1 → DC power supply DC1 → S4, realizing the superposition of DC power supply DC2 and capacitor C to generate a positive polarity output higher than the input voltage.

[0084] Step S440: when the target state is set to the charging state and the polarity of the target voltage is negative, the second lower bridge arm switch tube S4 is controlled to remain turned off, and the second upper bridge arm switch tube S3 is controlled to remain turned on.

[0085] Specifically, if Figure 13 and Figure 14 As shown, the state configuration of the second lower bridge arm switch tube S4 being turned off and the second upper bridge arm switch tube S3 being turned on is the same as the setting of step S420, but with a different PWM modulation strategy of the first switch tube group to realize the negative boost function of the Boost circuit.

[0086] It's easy to understand that the state control rules for the second switch group are consistent during negative polarity output. As an example, not a limitation, whether buck mode is used for negative polarity step-down or boost mode is used for negative polarity step-up, the second lower-arm switch S4 is turned off and the second upper-arm switch S3 is turned on, ensuring a unified control strategy and system predictability.

[0087] Specifically, during the energy storage phase when boost transistor S1 is on, current primarily flows between DC power supply DC2 and the inductor, preparing for a negative-polarity boost. The current path is: DC power supply DC2 positive electrode → S3 → S1 → inductor L → DC power supply DC2 negative electrode. During the energy release phase when freewheeling transistor S2 is on, the current path is: DC power supply DC2 positive electrode → S3 → DC power supply DC1 → S2 → inductor L → DC power supply DC2 negative electrode. Through this path, DC power supply DC2 and capacitor C achieve a negative-polarity boost output. Because the current direction is opposite to the positive-polarity mode, the output voltage polarity is also negative.

[0088] Different from the existing technology, the embodiments of the present invention can realize flexible switching between BUCK mode and BOOST mode under the same H-bridge circuit topology, overcome the defects of unipolar output, realize random combination of positive and negative bipolar voltage output and charge and discharge states, and expand the application scenarios and usage schemes of the H-bridge circuit.

[0089] The embodiment of the present invention also provides an electronic device based on the above H-bridge circuit control method, the structural diagram of which is shown in FIG. Figure 12 As shown, the electronic device 100 includes: One or more processors 101, network interface 102, and memory 103, Figure 12 In the figure, a processor 101, a network interface 102 and a memory 103 are taken as an example.

[0090] The network interface 102 is in communication with the corresponding processor 101, and the processor 101 and the memory 103 can be connected via a bus or other means. Figure 12 The bus connection is taken as an example.

[0091] The network interface 102 is used to establish a communication connection between the processor 101 and other external devices, and includes the following types of interfaces: RJ-45 interface, SC fiber optic interface, AUI interface, FDDI interface, and Console interface.

[0092] Memory 103, as a nonvolatile computer-readable storage medium, can be used to store nonvolatile software programs, nonvolatile computer-executable programs, and modules. Processor 101 executes the nonvolatile software programs, instructions, and units stored in memory 103 to perform various functional applications and data processing in the electronic device, thereby implementing the H-bridge circuit control method of the above-described method embodiment.

[0093] The memory 103 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and applications required for at least one function; the data storage area may store data created based on the use of the electronic device, etc. In addition, the memory 103 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory 103 may optionally include a memory remotely located relative to the processor 101, and these remote memories may be connected to the electronic device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0094] The one or more units are stored in the memory 103 , and when executed by one or more processors 101 , perform the H-bridge circuit control method in any of the above method embodiments.

[0095] The electronic device can execute the H-bridge circuit control method provided in the embodiment of the present invention, and has a corresponding program module and beneficial effects of the execution method. For technical details not fully described in the electronic device embodiment, please refer to the H-bridge circuit control method provided in the embodiment of the present invention.

[0096] In some embodiments of the present application, a switching power supply is further provided. The switching power supply includes an H-bridge circuit and the electronic device as described in the above embodiment.

[0097] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Based on the idea of ​​the present application, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the present application as above, which are not provided in detail for the sake of simplicity. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for controlling an H-bridge circuit, wherein the H-bridge circuit comprises a first switching tube group and a second switching tube group, wherein: The steps include: Setting a target state and a target voltage of the H-bridge circuit; Obtaining a duty cycle according to the output voltage and the target voltage; Performing PWM modulation on the first switch tube group according to the duty cycle, the target state, and the target voltage; According to the target state and the target voltage, the second switch tube group is controlled to maintain a corresponding on or off state, so that the charge and discharge state of the H-bridge circuit reaches the target state and the output voltage reaches the target voltage.

2. The method according to claim 1, characterized in that Obtaining the duty cycle according to the output voltage and the target voltage includes the following steps: The duty cycle is calculated according to the output voltage and the target voltage through dual closed-loop control; the dual closed-loop control includes a voltage outer loop with the output voltage and the target voltage as input, and a current inner loop with the output of the voltage outer loop as input.

3. The method according to claim 2, characterized in that The step of calculating the duty cycle by double closed-loop control according to the output voltage and the target voltage comprises the following steps: Inputting the difference between the output voltage and the target voltage as an error signal into a first PI controller to obtain a voltage loop output; Limiting the voltage loop output; The voltage loop output after limiting is used as input to a second PI controller to obtain the duty cycle.

4. The method according to claim 1, wherein The first switch tube group includes a first upper-arm switch tube S1 and a first lower-arm switch tube S2. The PWM modulation of the first switch tube group according to the duty cycle, the target state, and the target voltage includes the following steps: When the target state is set to the discharge state and the polarity of the target voltage is positive, the first upper arm switch tube S1 functions as a buck tube, and the on-time of the first upper arm switch tube S1 is controlled according to the duty cycle to output the target voltage; When the target state is set to the discharge state and the polarity of the target voltage is negative, the first lower bridge arm switch tube S2 serves as a BUCK tube, and the conduction time of the first lower bridge arm switch tube S2 is controlled according to the duty cycle to output the target voltage.

5. The method according to claim 4, characterized in that The performing PWM modulation on the first switch tube group according to the duty cycle, the target state and the target voltage further includes the following steps: When the target state is set to the charging state and the polarity of the target voltage is positive, the first lower bridge arm switch tube S2 is used as a BOOST tube, the on-time of the first lower bridge arm switch tube S2 is controlled according to the duty cycle, and the first upper bridge arm switch tube S1 is controlled to be a freewheeling tube; When the target state is set to the charging state and the polarity of the target voltage is negative, the first upper arm switch tube S1 serves as a BOOST tube, and the conduction time of the first upper arm switch tube S1 is controlled according to the duty cycle, and the first lower arm switch tube S2 is controlled to serve as a freewheeling tube.

6. The method according to claim 5, characterized in that The BOOST tube or the BUCK tube is turned on before the freewheeling tube.

7. The method according to claim 1, characterized in that The second switch tube group includes a second upper-arm switch tube S3 and a second lower-arm switch tube S4. Controlling the second switch tube group to maintain a corresponding on or off state according to the target state and the target voltage includes the following steps: When the target state is set to the discharge state and the polarity of the target voltage is positive, the second upper bridge arm switch tube S3 is controlled to remain turned off, and the second lower bridge arm switch tube S4 is controlled to remain turned on; When the target state is set to the discharge state and the polarity of the target voltage is negative, the second lower bridge arm switch tube S4 is controlled to remain turned off, and the second upper bridge arm switch tube S3 is controlled to remain turned on.

8. The method according to claim 7, characterized in that The controlling the second switch tube group to maintain a corresponding on or off state according to the target state and the target voltage further includes the following steps: When the target state is set to the charging state and the polarity of the target voltage is positive, the second upper bridge arm switch tube S3 is controlled to remain turned off, and the second lower bridge arm switch tube S4 is controlled to remain turned on; When the target state is set to the charging state and the polarity of the target voltage is negative, the second lower bridge arm switch tube S4 is controlled to remain turned off, and the second upper bridge arm switch tube S3 is controlled to remain turned on.

9. An electronic device, characterized in that: include: at least one processor; at least one network interface, the network interface being communicatively connected to a corresponding processor; as well as, a memory communicatively connected to the at least one processor; wherein, The network interface is used to establish a communication connection between the processor and other external devices; The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the H-bridge circuit control method according to any one of claims 1 to 8.

10. A switching power supply, characterized in that: include: H-bridge circuit; as well as The electronic device according to claim 9.

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