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

Abstract

The embodiment of the application discloses an H-bridge circuit control method, electronic equipment and switching power supply. The control method is for an H-bridge circuit comprising a first switch tube group and a second switch tube group, and comprises: setting a target state and a target voltage of the H-bridge circuit; obtaining a duty cycle according to an output voltage and the target voltage; PWM modulating the first switch tube group according to the duty cycle, the target state and the target voltage; and controlling the second switch tube group to keep a corresponding conduction or cut-off state according to the target state and the target voltage, 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 the above manner, the embodiment of the application can realize flexible switching of BUCK mode and BOOST mode under the same H-bridge circuit topology, overcome the defect of single polarity output, realize random combination of positive and negative bipolar voltage output and charge and discharge state, and expand the application scene and use scheme of the H-bridge circuit.

Description

TECHNICAL FIELD

[0001] The embodiment of the present application relates to the field of switching power supply, in particular to an H-bridge circuit control method, electronic equipment and switching power supply. BACKGROUND

[0002] In the field of power electronics, DC-DC converters are the core devices for realizing DC voltage conversion and are widely used in various electronic devices and systems. Currently, the three basic DC-DC topologies widely used in switching power supplies are buck circuit (Buck), boost circuit (Boost) and buck-boost circuit (Buck-Boost).

[0003] The Buck circuit can realize the function of reducing the output voltage below the input voltage, and the output voltage and the input voltage maintain the same polarity. The Boost circuit can realize the function of increasing the output voltage above the input voltage, and the output voltage and the input voltage also maintain the same polarity. The Buck-Boost circuit can realize the function of increasing or reducing the voltage, but the output voltage and the input voltage are opposite in polarity.

[0004] However, the prior art has the following defects: whether it is a Buck circuit, a Boost circuit or a Buck-Boost circuit, it can only realize single-polarity voltage output. Specifically, the output voltage and the input voltage of the Buck circuit and the Boost circuit always maintain the same polarity; and although the output voltage and the input voltage of the Buck-Boost circuit are opposite in polarity, it can still only output a single-polarity voltage. This limitation makes the traditional DC-DC converter unable to realize positive and negative bipolar voltage output in the same circuit topology, limiting its use in applications requiring bipolar power supply. SUMMARY

[0005] The technical problem solved by the embodiment of the present application is to provide an H-bridge circuit control method, electronic equipment and switching power supply, which can solve at least part of the defects existing in the prior art.

[0006] In a first aspect, the embodiment of the present application provides an H-bridge circuit control method, the H-bridge circuit comprising a first switch tube group and a second switch tube group, comprising the following steps: setting a target state and a target voltage of the H-bridge circuit; obtaining a duty cycle according to an output voltage and the target voltage; PWM modulating the first switch tube group according to the duty cycle, the target state and the target voltage; controlling the second switch tube group to maintain a corresponding conduction or cutoff state according to the target state and the target voltage, so that the charge and discharge state of the H-bridge circuit reaches the target state, and the output voltage reaches the target voltage.

[0007] Optionally, the obtaining the duty cycle according to the output voltage and the target voltage comprises: calculating the duty cycle according to the output voltage and the target voltage by double closed-loop control; the double closed-loop control comprises a voltage outer loop taking the output voltage and the target voltage as inputs, and a current inner loop taking an output of the voltage outer loop as an input.

[0008] Optionally, the calculating the duty cycle according to the output voltage and the target voltage by double closed-loop control comprises: inputting a difference between the output voltage and the target voltage as an error signal to a first PI controller to obtain a voltage loop output; limiting the voltage loop output; and inputting the limited voltage loop output to a second PI controller to obtain the duty cycle.

[0009] Optionally, the first switch tube group comprises a first upper bridge arm switch tube S1 and a first lower bridge 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 comprises: when the target state is set to a discharging state and a polarity of the target voltage is positive, the first upper bridge arm switch tube S1 is used as a BUCK tube to control a conduction time of the first upper bridge arm switch tube S1 according to the duty cycle to output the target voltage; and when the target state is set to the discharging state and the polarity of the target voltage is negative, the first lower bridge arm switch tube S2 is used as a BUCK tube to control a conduction time of the first lower bridge arm switch tube S2 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 further comprises: when the target state is set to a charging state and a polarity of the target voltage is positive, the first lower bridge arm switch tube S2 is used as a BOOST tube to control a conduction time of the first lower bridge arm switch tube S2 according to the duty cycle, and the first upper bridge arm switch tube S1 is used as a freewheeling tube; and 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 to control a conduction time of the first upper bridge arm switch tube S1 according to the duty cycle, and the first lower bridge arm switch tube S2 is used as a freewheeling tube.

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

[0012] Optionally, the second switch tube group comprises a second upper bridge arm switch tube S3 and a second lower bridge arm switch tube S4, and the step of controlling the second switch tube group to keep a corresponding conduction or cut-off state according to the target state and the target voltage comprises the following steps: when the target state is set as the discharging state and the polarity of the target voltage is positive, the second upper bridge arm switch tube S3 is controlled to keep cut-off and the second lower bridge arm switch tube S4 is controlled to keep conduction; when the target state is set as the discharging state and the polarity of the target voltage is negative, the second lower bridge arm switch tube S4 is controlled to keep cut-off and the second upper bridge arm switch tube S3 is controlled to keep conduction.

[0013] Optionally, the step of controlling the second switch tube group to keep a corresponding conduction or cut-off state according to the target state and the target voltage further comprises the following steps: when the target state is set as the charging state and the polarity of the target voltage is positive, the second upper bridge arm switch tube S3 is controlled to keep cut-off and the second lower bridge arm switch tube S4 is controlled to keep conduction; when the target state is set as the charging state and the polarity of the target voltage is negative, the second lower bridge arm switch tube S4 is controlled to keep cut-off and the second upper bridge arm switch tube S3 is controlled to keep conduction.

[0014] In a second aspect, an embodiment of the present application provides an electronic device, comprising: at least one processor; at least one network interface, which is in communication connection with the corresponding processor; and a memory in communication connection with the at least one processor; wherein the network interface is configured to establish a communication connection between the processor and other external devices; and the memory stores instructions executable 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 the first aspect.

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

[0016] The embodiment of the present application has the following beneficial effects: different from the prior art, the embodiment of the present application can realize flexible switching between the BUCK mode and the BOOST mode under the same H-bridge circuit topology, overcome the defect of single-polarity output, realize random combination of positive and negative bipolar voltage output and charging and discharging states, and expand the application scenarios and use schemes of the H-bridge circuit. BRIEF DESCRIPTION OF DRAWINGS

[0017] One or more embodiments are illustrated by way of example with reference to the accompanying drawings, which are schematic and not intended to be limiting of the embodiments, and in which like reference numerals designate similar elements in the figures and wherein: the figures do not limit the present application to the scale of the drawings.

[0018] Figure 1 is a structural schematic diagram of a Buck circuit in the prior art;

[0019] Figure 2 is a structural schematic diagram of a Boost circuit in the prior art;

[0020] Figure 3 is a structural schematic diagram of a Buck-Boost circuit in the prior art;

[0021] Figure 4 is a structural schematic diagram of an H-bridge circuit;

[0022] Figure 5 is a flowchart of an H-bridge circuit control method provided by an embodiment of the present application;

[0023] Figure 6 is a control block diagram for calculating a duty cycle;

[0024] Figure 7 shows a current loop of the BUCK transistor being turned on when the H-bridge circuit is set to a discharging state and the polarity of the target voltage is positive;

[0025] Figure 8 shows a current loop of the freewheeling transistor being turned on when the H-bridge circuit is set to a discharging state and the polarity of the target voltage is positive;

[0026] Figure 9 shows a current loop of the BUCK transistor being turned on when the H-bridge circuit is set to a discharging state and the polarity of the target voltage is negative;

[0027] Figure 10 shows a current loop of the freewheeling transistor being turned on when the H-bridge circuit is set to a discharging state and the polarity of the target voltage is negative;

[0028] Figure 11 shows a current loop of the BOOST transistor being turned on when the H-bridge circuit is set to a charging state and the polarity of the target voltage is positive;

[0029] Figure 12 shows a current loop of the freewheeling transistor being turned on when the H-bridge circuit is set to a charging state and the polarity of the target voltage is positive;

[0030] Figure 13 shows a current loop of the BOOST transistor being turned on when the H-bridge circuit is set to a charging state and the polarity of the target voltage is negative;

[0031] Figure 14 shows a current loop of the freewheeling transistor being turned on when the H-bridge circuit is set to a charging state and the polarity of the target voltage is negative;

[0032] Figure 15 is a structural schematic diagram of an electronic device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0033] For the purpose of facilitating the understanding of the present application, the present application will be 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 one or more intervening elements can be present therebetween. When an element is described as being "connected to" another element, it can be directly connected to the other element or one or more intervening elements can be present therebetween. The terms "upper", "lower", "inner", "outer", "bottom", and the like as used in the present specification indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are merely used for the purpose of facilitating the description of the present application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", "third", and the like are merely used for the purpose of description and cannot be understood as indicating or implying relative importance.

[0034] Unless otherwise defined, all technical and scientific terms used in the present specification have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs. The terms used in the present specification are merely used for the purpose of describing specific embodiments of the present application and are not intended to limit the present application. The term "and / or" used in the present specification includes any and all combinations of one or more related listed items.

[0035] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as there is no conflict.

[0036] The technical solutions in the present application will be described below in conjunction with the accompanying drawings.

[0037] In the field of power electronics, three basic DC-DC topologies are widely used in switching power supplies. As an example but not limitation, the Buck circuit shown in Figure 1 can realize the function of voltage reduction, and the output voltage is lower than the input voltage and maintains the same polarity as the input voltage; the Boost circuit shown in Figure 2 can realize the function of voltage increase, and the output voltage is higher than the input voltage and maintains the same polarity as the input voltage; and the Buck-Boost circuit shown in Figure 3 can realize the functions of voltage increase and voltage reduction at the same time, but the output voltage is opposite in polarity to the input voltage.

[0038] The existing conventional topologies have obvious technical defects. Specifically, the Buck circuit, the Boost circuit and the Buck-Boost circuit can only realize single-polarity voltage output, and cannot flexibly generate positive or negative output voltage according to application requirements. It is not difficult to understand that when some application scenarios need to output both positive and negative voltages, the traditional single topology cannot meet the technical requirements of such bipolar output.

[0039] As an example but not limitation, in the application fields of motor drive, battery charging and discharging management, bidirectional power conversion, etc., a power supply system capable of flexibly controlling the polarity of the output voltage is often needed. Specifically, positive and negative bidirectional voltage drive is needed for motor forward and reverse control, and both charging mode and discharging mode are needed for battery system.

[0040] As an example but not limitation, the H-bridge circuit shown in Figure 4 includes a DC power supply DC, a switch tube S1, a switch tube S2, a switch tube S3, a switch tube S4, an inductor L, a capacitor C and a load R. Specifically, the switch tubes S1 and S3 constitute the upper bridge arm, the switch tubes S2 and S4 constitute the lower bridge arm, the inductor L is connected between the two midpoints of the H-bridge circuit, and the capacitor C is connected in parallel with the load R at the output end of the circuit. As a classic circuit topology, the H-bridge circuit has the hardware foundation to realize bipolar output in structure, but in the prior art, it is mainly used as a full-bridge inverter circuit to realize DC-AC conversion function and convert DC into AC. It is not difficult to understand that the conventional H-bridge application scheme does not fully exert its potential in the field of DC-DC conversion, especially in the application value of realizing adjustable positive and negative voltage output.

[0041] As an example but not limitation, the existing H-bridge inverter application usually adopts the way of alternatingly turning on the diagonal switch tubes to generate AC output, but lacks a special control strategy for adjustable positive and negative voltage output in DC-DC conversion. Specifically, how to reasonably allocate the working mode of the four switch tubes, how to realize flexible switching between charging and discharging states, and how to ensure the stability of the circuit in different polarity output, the above key technical problems have not been effectively solved in the prior art.

[0042] Based on the above problems, the H-bridge circuit control method provided by the embodiments of the present application has a flowchart as shown in Figure 5 , and specifically includes the following steps:

[0043] S100: Set the target state and target voltage of the H-bridge circuit

[0044] In some embodiments of the present application, the control system first needs to determine the working target of the H-bridge circuit. Specifically, the working target includes a target state and a target voltage, the target state includes two working modes of a charging state and a discharging state, and the target voltage includes two parameters of a voltage amplitude and a voltage polarity. It is not difficult to understand that the charging state corresponds to the working characteristics of the Boost circuit, and the discharging state corresponds to the working characteristics of the Buck circuit.

[0045] By way of example and not limitation, when the application requirement of the H-bridge circuit is battery charging, the control system sets the target state to the charging state, and sets the corresponding target voltage amplitude according to the rated voltage of the battery. When the application requirement of the H-bridge circuit is to supply power to the load, the control system sets the target state to the discharging state, and the polarity of the target voltage can be set to positive or negative according to the load characteristics.

[0046] S200: obtaining a duty cycle according to the output voltage and the target voltage

[0047] In some embodiments of the present application, the control system calculates the duty cycle required for PWM modulation according to the output voltage and the target voltage through a closed-loop control algorithm. Specifically, a double closed-loop control structure is adopted, the outer loop is a voltage loop, and the inner loop is a current loop, to ensure that the output voltage can accurately track the target voltage.

[0048] S300: PWM modulating the first switch tube group according to the duty cycle, the target state and the target voltage

[0049] In some embodiments of the present application, the first switch tube group includes a first upper bridge arm switch tube S1 and a first lower bridge arm switch tube S2, and this step differentially PWM modulates the first upper bridge arm switch tube S1 and the first lower bridge arm switch tube S2 according to the aforementioned parameters. Specifically, the first upper bridge arm switch tube S1 and the first lower bridge arm switch tube S2 adopt a complementary high-frequency switching mode, one of which is a main power switch tube and the other is a freewheeling switch tube.

[0050] Specifically, when the target state is discharging state and the target voltage polarity is positive, the first upper bridge arm switch S1 works as a Buck tube to control the on time according to the duty cycle, and the first lower bridge arm switch S2 works as a freewheeling tube to provide a freewheeling path for the inductor current. When the target state is discharging state and the target voltage polarity is negative, the first lower bridge arm switch S2 works as a Buck tube to control the on time according to the duty cycle, and the first upper bridge arm switch S1 works as a freewheeling tube to provide a freewheeling path for the inductor current. When the target state is charging state and the target voltage polarity is positive, the first lower bridge arm switch S2 works as a Boost tube to control the on time according to the duty cycle, and the first upper bridge arm switch S1 works as a freewheeling tube to cooperate with the inductor energy storage and release process. When the target state is charging state and the target voltage polarity is negative, the first upper bridge arm switch S1 works as a Boost tube to control the on time according to the duty cycle, and the first lower bridge arm switch S2 works as a freewheeling tube to cooperate with the inductor energy storage and release process.

[0051] The on time of the main power switch is directly determined by the duty cycle. The greater the duty cycle, the longer the on time, and the greater the output power. The freewheeling switch is turned on during the off period of the main power switch to provide a continuous flow path for the inductor current, preventing voltage spikes caused by sudden changes in inductor current.

[0052] S400: According to the target state and the target voltage, the second switch group is controlled to keep the 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

[0053] In some embodiments of the present application, the second switch group includes a second upper bridge arm switch S3 and a second lower bridge arm switch S4. The second upper bridge arm switch S3 and the second lower bridge arm switch S4 are set to a long on or off state and do not perform high frequency switching.

[0054] Specifically, when the target voltage polarity is positive, whether in charging or discharging state, the second upper bridge arm switch S3 is kept off and the second lower bridge arm switch S4 is kept on, so that the current can flow from the top to the bottom of the H bridge. As an example but not limitation, when the target voltage polarity is negative, the second lower bridge arm switch S4 is kept off and the second upper bridge arm switch S3 is kept on, so that the current flow is reversed and a voltage opposite to the positive polarity is generated across the load.

[0055] In some embodiments of the present application, step S200 specifically includes the following steps:

[0056] Step S210: According to the output voltage and the target voltage, the duty cycle is calculated by double closed loop control.

[0057] In some embodiments of the present application, the double closed-loop control structure includes two control loops, i.e., a voltage outer loop and a current inner loop. Specifically, the voltage outer 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 current inner loop takes the output of the voltage outer loop as input, and is responsible for providing fast dynamic response and good current regulation performance.

[0058] In some embodiments of the present application, step S210 specifically includes the following steps:

[0059] Step S211: input the difference between the output voltage and the target voltage as an error signal to the first PI controller, and obtain the voltage loop output.

[0060] In some embodiments of the present application, the control system first takes 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 the first PI controller, and the first PI controller processes the error signal according to the proportional integral algorithm to obtain the voltage loop output.

[0061] The proportional element of the first PI controller can quickly respond to changes in voltage error, and the integral element can eliminate the steady-state error of the system. As an example but not limitation, when the output voltage is lower than the target voltage, the error signal is positive, and the first PI controller outputs a positive adjustment signal indicating that the system needs to increase power transmission; when the output voltage is higher than the target voltage, the error signal is negative, and the first PI controller outputs a negative adjustment signal indicating that the system needs to reduce power transmission.

[0062] Specifically, the transfer function of the first PI controller can be represented as Kp1 + Ki1 / s, where Kp1 is the proportional coefficient and Ki1 is the integral coefficient.

[0063] Step S212: limit the voltage loop output.

[0064] In some embodiments of the present application, the output of the first PI controller needs to be limited to prevent the control signal from being too large and causing system instability or hardware damage. Specifically, the limiting element limits the voltage loop output between a pre-set upper limit and a lower limit, ensuring that the subsequent current loop input signal is within a reasonable range.

[0065] As an example but not limitation, when the system starts or the load changes suddenly, the voltage error may be large, and the output of the first PI controller may exceed the normal working range, at which time the limiting element can timely constrain the control signal to prevent the system from overshooting or oscillating. Specifically, the upper limit of the limiting is usually determined according to the maximum allowable value of the inductor current, and the lower limit of the limiting considers the minimum working current requirement of the circuit.

[0066] Step S213: the amplitude-limited voltage loop output is taken as an input to the second PI controller to obtain a duty cycle.

[0067] In some embodiments of the present application, the amplitude-limited voltage loop output is taken as an input signal of the second PI controller, and the second PI controller generates a final duty cycle Duty based on a current regulation algorithm. Specifically, the second PI controller constitutes a current inner loop in a double closed-loop control structure, and its output directly acts on PWM modulation of the first switch group in the H-bridge circuit.

[0068] By way of example but not limitation, a larger proportional coefficient Kp2 can improve the response speed of the system, but too large a coefficient can cause the system to be unstable; a proper integral coefficient Ki2 can improve the steady-state performance of the system, but improper setting can cause integral saturation problems.

[0069] Specifically, the output duty cycle Duty of the second PI controller usually ranges from 0 to 1, corresponding to the proportion of the switch-on time of the switch to the switching period. When the Duty value is larger, the switch-on time of the switch is longer, and the power transmitted to the load is larger; when the Duty value is smaller, the switch-on time of the switch is shorter, and the power transmitted to the load is smaller.

[0070] In some embodiments of the present application, step S300 specifically includes the following steps:

[0071] Step S310: when the target state is set to the discharging state and the polarity of the target voltage is positive, the first upper arm switch S1 acts as a BUCK tube, and the conduction time of the first upper arm switch S1 is controlled according to the duty cycle, and the first lower arm switch S2 acts as a freewheeling tube.

[0072] Specifically, as shown in Figure 7 When the first upper arm switch S1 is turned on, the current flows from the positive electrode of the DC power supply DC, passes through the first upper arm switch 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.

[0073] It is not difficult to understand that the first upper arm switch S1 acts as a Buck tube and undertakes the role of main power switching, and its conduction time is directly determined by the duty cycle. By way of example but not limitation, during the conduction period of the first upper arm switch S1, the current in the inductor increases linearly, and the inductor generates self-induction phenomenon, which hinders the rapid rise of the current. The inductor converts the input electrical energy into magnetic energy and stores it.

[0074] Again as shown in Figure 8As shown, when the first upper bridge arm switch S1 is off, the first lower bridge arm switch S2 is immediately on as a freewheeling diode to provide a continuous current path for the inductor current. Since the inductor current cannot suddenly become zero, the inductor begins to release the stored magnetic energy, and the current forms a freewheeling loop through the first lower bridge arm switch S2 and the load R, and the inductor current gradually decreases. Through the alternating on and off of the first upper bridge arm switch S1 and the first lower bridge arm switch S2, the input voltage is stepped down and output, and the output voltage is lower than the input voltage and remains positive.

[0075] The first upper bridge arm switch S1 as a Buck tube must be established before the freewheeling diode S2 is on. Specifically, at the beginning of each PWM switching cycle, the control system first makes the first upper bridge arm switch S1 on, establishes a current path from the DC power supply through the first upper bridge arm switch S1, the inductor L to the load R, and then controls the on of the freewheeling diode S2. If the freewheeling diode S2 is on before the Buck tube S1, it may cause a sharp change in the voltage across the inductor, leading to a dangerous impact current due to a large di / dt, affecting system stability and possibly damaging the switch and other circuit elements.

[0076] Specifically, the on time of the Buck tube S1 is strictly controlled by the duty cycle, and the change of the duty cycle must be in a slow and gradual manner rather than a sudden manner. When the system starts or the working mode switches, the duty cycle gradually increases from the initial value to the target value, ensuring smooth growth of the inductor current and avoiding adverse effects of instantaneous impact on the circuit.

[0077] Step S320: When the target state is set to the discharging state and the polarity of the target voltage is negative, the first lower bridge arm switch S2 as a BUCK tube controls the on time of the first lower bridge arm switch S2 according to the duty cycle, and controls the first upper bridge arm switch S1 as a freewheeling diode.

[0078] Specifically, as shown in Figure 9 When the first lower bridge arm switch S2 is on, the current flows from the second upper bridge arm switch S3 through the inductor L to the load R, and then forms a loop through the first lower bridge arm switch S2. At this time, the current direction is opposite to that in step S310, and a negative polarity voltage output is generated across the load.

[0079] It is not difficult to understand that when the first lower bridge arm switch S2 as a Buck tube, its working principle is similar to that of the first upper bridge arm switch S1 in step S310, but the current flow direction has changed fundamentally. As an example but not limitation, during the on period of the first lower bridge arm switch S2, the current in the inductor flows from the second upper bridge arm switch S3 end to the first lower bridge arm switch S2 end, the inductor stores magnetic energy, and the inductor current linearly increases, and the self-induction phenomenon also hinders the rapid rise of the current.

[0080] Again,Figure 10 As shown, when the first lower bridge arm switch S2 is off, the first upper bridge arm switch S1 is on as a freewheeling diode, the inductor releases the stored magnetic energy, and the current flows through the first upper bridge arm switch S1, the load R, and the second upper bridge arm switch S3 to form a freewheeling circuit. Since the current direction is opposite to the positive polarity output, the voltage polarity across the load is also reversed accordingly, achieving a negative polarity step-down output.

[0081] The first lower bridge arm switch S2 as a Buck tube must also establish a conduction state before the freewheeling diode S1. Specifically, the control system first drives the first lower bridge arm switch S2 to be on at the beginning of each switching period, establishing a negative polarity current path, and the freewheeling diode S1 begins to conduct only after the first lower bridge arm switch S2 is off, providing a freewheeling path for the inductor current. The priority conduction of the Buck tube S2 ensures that the negative inductor current can be established smoothly, avoiding electromagnetic interference and voltage oscillation phenomena that may be caused by sudden changes in current direction.

[0082] In this mode, gradual adjustment of the duty cycle is particularly important, as the negative polarity output involves a complete reversal of the current direction, and a smooth transition of the current is more necessary through slow changes in the duty cycle to prevent excessive transient current during the positive and negative polarity switching process.

[0083] 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 S2 as a BOOST tube controls the conduction time of the first lower bridge arm switch S2 according to the duty cycle, and the first upper bridge arm switch S1 as a freewheeling diode.

[0084] Specifically, as shown in Figure 11 When the first lower bridge arm switch S2 is on, the inductor is directly connected to the right DC power supply (DC2), the current in the inductor increases linearly, the self-inductance of the inductor hinders the rise of the current, and the inductor stores the electrical energy as magnetic energy. At this time, the energy is mainly provided by the capacitor C.

[0085] It is not difficult to understand that the working principle of the Boost circuit is significantly different from that of the Buck circuit. As an example, but not limited to, during the inductor energy storage stage when the first lower bridge arm switch S2 is on, the DC power supply DC2 does not directly charge the DC power supply DC1, but first charges the inductor L, and the inductor current continues to grow, preparing for the subsequent energy release stage.

[0086] As shown in Figure 12 When the first lower bridge arm switch S2 is off, the first upper bridge arm switch S1 is on as a freewheeling diode, and the inductor begins to release the stored magnetic energy. At this time, the DC power supply and the inductor L supply power to the load R simultaneously, achieving a step-up effect with an output voltage higher than the input voltage. Due to the superimposed supply of the DC power supply and the inductor, the output voltage can exceed the input voltage while maintaining a positive polarity.

[0087] Specifically, the Boost tube S2 is first turned on to establish an inductive energy storage loop, and the inductive current increases linearly from zero. When the inductive energy storage is sufficient, the Boost tube S2 is turned off, and the freewheeling tube S1 is turned on immediately to release the inductive energy and achieve the output voltage boost. If the freewheeling tube S1 is turned on before the Boost tube S2 completes the energy storage, the inductive energy storage will be insufficient, and the effective voltage boost cannot be achieved, which may cause a short circuit of the DC power supply or an out-of-control inductive current.

[0088] Specifically, the on-time of the Boost tube S2 needs to be precisely controlled. If the on-time is too short, the inductive energy storage will be insufficient, and the voltage boost will be ineffective. If the on-time is too long, the inductive current will be too large, exceeding the safe working range.

[0089] Step S340: 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 the Boost tube, the on-time of the first upper bridge arm switch tube S1 is controlled according to the duty ratio, and the first lower bridge arm switch tube S2 is used as the freewheeling tube.

[0090] Specifically, as shown in FIG. 3B, when the first upper bridge arm switch tube S1 is turned on, the current in the inductor increases linearly. The inductance hinders the current from rising, and the inductor converts the electrical energy into magnetic energy and stores it. The current direction is opposite to that in step S330. Figure 13 As can be understood, the inductive energy storage process in this working mode is similar to that in step S330, but the current flow direction is completely opposite. As an example but not limitation, during the on-time of the first upper bridge arm switch tube S1, the inductor stores energy through the DC power supply DC2 connected thereto, preparing for the subsequent negative polarity voltage boost output.

[0091] As shown in FIG. 3B, when the first upper bridge arm switch tube S1 is turned off, the first lower bridge arm switch tube S2 is turned on as the freewheeling tube, and the inductor releases the stored magnetic energy. At this time, the DC power supply DC and the inductor L supply power to the load R at the same time, but since the current direction is opposite to that in step S330, a negative polarity voltage boost output is generated across the load, achieving the Boost conversion function of outputting a voltage higher than the input voltage and having a negative polarity.

[0092] Figure 14 Specifically, the Boost tube S1 is first turned on to store inductive energy, establishing a negative inductive current. The freewheeling tube S2 is turned on after the Boost tube S1 is turned off, cooperating with the inductor to complete the negative polarity voltage boost energy release process. The preferential on of the Boost tube S1 not only ensures the sufficiency of inductive energy storage, but also ensures the stability of the negative inductive current, avoiding current surges and voltage overshoots during the positive and negative polarity conversion process. Figure 14 As shown in FIG. 3B, when the first upper bridge arm switch tube S1 is turned off, the first lower bridge arm switch tube S2 is turned on as the freewheeling tube, and the inductor releases the stored magnetic energy. At this time, the DC power supply DC and the inductor L supply power to the load R at the same time, but since the current direction is opposite to that in step S330, a negative polarity voltage boost output is generated across the load, achieving the Boost conversion function of outputting a voltage higher than the input voltage and having a negative polarity.

[0093] Specifically, the Boost tube S1 is first turned on to store inductive energy, establishing a negative inductive current. The freewheeling tube S2 is turned on after the Boost tube S1 is turned off, cooperating with the inductor to complete the negative polarity voltage boost energy release process. The preferential on of the Boost tube S1 not only ensures the sufficiency of inductive energy storage, but also ensures the stability of the negative inductive current, avoiding current surges and voltage overshoots during the positive and negative polarity conversion process.

[0094] In some embodiments of the present application, step S400 specifically comprises the following steps:

[0095] Step S410: When the target state is set to the discharging state and the polarity of the target voltage is positive, the second upper bridge arm switch S3 is controlled to remain off, and the second lower bridge arm switch S4 is controlled to remain on.

[0096] Specifically, as shown in Figure 7 and Figure 8 , the second upper bridge arm switch S3 remains in a long-time off state, and the second lower bridge arm switch S4 remains in a long-time on state, cooperating with the PWM modulation of the first switch group S1, S2, to realize the forward voltage reduction output of the Buck circuit.

[0097] It is not difficult to understand that the state setting of the second switch group directly determines the current flow path in the H-bridge circuit. As an example but not limitation, when the second upper bridge arm switch S3 is off and the second lower bridge arm switch S4 is on, the current can only flow from the upper to the lower of the H-bridge circuit, i.e. from the first upper bridge arm switch S1 to the load R through the inductor L, and then returns to the negative pole of the circuit through the second lower bridge arm switch S4, forming a forward current loop.

[0098] Specifically, in the Buck tube S1 on phase, the current path is: DC power supply positive pole→S1→inductor L→load R→S4→DC power supply negative pole; in the freewheeling tube S2 on phase, the current path is: S2→inductor L→load R→S4→S2, forming a closed freewheeling loop. The off state of the second upper bridge arm switch S3 ensures that the current cannot pass through the right path of the upper bridge arm, and the on state of the second lower bridge arm switch S4 provides a stable return path for the current in the lower bridge arm, thereby generating a positive polarity voltage across the load.

[0099] Step S420: When the target state is set to the discharging state and the polarity of the target voltage is negative, the second lower bridge arm switch S4 is controlled to remain off, and the second upper bridge arm switch S3 is controlled to remain on.

[0100] Specifically, as shown in Figure 9 and Figure 10 , the second lower bridge arm switch S4 remains in an off state, and the second upper bridge arm switch S3 remains in an on state, cooperating with the PWM modulation of the first switch group, and the current direction is completely opposite to that of step S410.

[0101] It is not difficult to understand that by changing the conduction state of the second switch tube group, the flexible switching of the current polarity can be realized. As an example but not limitation, when the second lower arm switch tube S4 is off and the second upper arm switch tube S3 is on, the current is forced to flow from the lower to the upper of the H-bridge circuit, that is, from the second upper arm switch tube S3 to the load R through the inductor L, and then returns through the corresponding switch tube, forming a negative current loop.

[0102] Specifically, in the Buck tube S2 conduction phase, the current path is: DC power positive pole→S3→load R→inductor L→S2→DC power negative pole; in the freewheeling tube S1 conduction phase, the current path is: S3→load R→inductor L→S1. Since the current direction is opposite to that of the positive polarity mode, the voltage polarity across the load is also reversed accordingly, realizing the negative polarity Buck step-down output. The off state of the second lower arm switch tube S4 blocks the current path of the lower arm, and the on state of S3 provides a flow path for the reverse current in the upper arm.

[0103] Step S430: When the target state is set to the charging state and the polarity of the target voltage is positive, control the second upper arm switch tube S3 to remain off and control the second lower arm switch tube S4 to remain on.

[0104] Specifically, as shown in Figure 11 and Figure 12 , the state configuration of the second upper arm switch tube S3 being off and the second lower arm switch tube S4 being on cooperates with the first switch tube group to realize the positive step-up output function of the Boost circuit.

[0105] It is not difficult to understand that the state settings of the second switch tube group remain the same when the same polarity output is required in the charging state and the discharging state. As an example but not limitation, whether in Buck mode or Boost mode, as long as positive polarity output is required, the second upper arm switch tube S3 remains off and the second lower arm switch tube S4 remains on, ensuring the consistency of the current flow direction.

[0106] Specifically, in the energy storage phase of the Boost tube S2 conduction, as shown in Figure 11 , the current path is mainly: DC power DC2 positive pole→inductor L→S2→S4→DC power DC2 negative pole. As shown in Figure 12 , in the energy release phase of the freewheeling tube S1 conduction, the current path is: capacitor C→inductor L→S1→DC power DC1→S4, realizing the superimposed power supply of DC power DC2 and capacitor C, and generating a positive polarity output higher than the input voltage.

[0107] Step S440: When the target state is set to the charging state and the polarity of the target voltage is negative, control the second lower arm switch tube S4 to remain off and control the second upper arm switch tube S3 to remain on.

[0108] Specifically, as shown in Figure 13 and Figure 14 The state configuration of the second lower bridge arm switch tube S4 being off and the second upper bridge arm switch tube S3 being on is the same as the setting of step S420, but cooperates with different first switch tube group PWM modulation strategies to realize the negative boost function of the Boost circuit.

[0109] It is not difficult to understand that the state control rule of the second switch tube group has consistency when the negative polarity output. As an example but not limited, whether it is negative polarity step-down of Buck mode or negative polarity step-up of Boost mode, the configuration of the second lower bridge arm switch tube S4 being off and the second upper bridge arm switch tube S3 being on is adopted to ensure the uniformity of the control strategy and the predictability of the system.

[0110] Specifically, in the energy storage stage of the Boost tube S1 being on, the current mainly flows between the direct current power supply DC2 and the inductor, preparing for the negative polarity step-up, and the current path is: the positive pole of the direct current power supply DC2→S3→S1→the inductor L→the negative pole of the direct current power supply DC2. In the energy release stage of the freewheeling tube S2 being on, the current path is: the positive pole of the direct current power supply DC2→S3→the direct current power supply DC1→S2→the inductor L→the negative pole of the direct current power supply DC2. The direct current power supply DC2 and the capacitor C realize the negative polarity step-up output through the above path. Since the current direction is opposite to that of the positive polarity mode, the polarity of the output voltage is also negative.

[0111] Different from the prior art, the embodiment of the present application can realize flexible switching of BUCK mode and BOOST mode under the same H-bridge circuit topology, overcome the defects of single polarity output, realize random combination of positive and negative bipolar voltage output and charging and discharging state, and expand the application scenarios and use schemes of the H-bridge circuit.

[0112] The embodiment of the present application also provides an electronic device based on the above-mentioned H-bridge circuit control method, and a structure diagram thereof is shown in Figure 12 The electronic device 100 comprises:

[0113] one or more processors 101, a network interface 102, and a memory 103, Figure 12 For example, one processor 101, one network interface 102, and one memory 103 are taken as an example.

[0114] The network interface 102 and the corresponding processor 101 are in communication connection, and the processor 101 and the memory 103 can be connected through a bus or other means, Figure 12 For example, a bus connection is taken as an example.

[0115] The network interface 102 is configured to establish a communication connection between the processor 101 and other external devices, including the following types: RJ-45 interface, SC optical fiber interface, AUI interface, FDDI interface, Console interface and other interface types.

[0116] The memory 103 is a non-volatile computer readable storage medium, which is configured to store non-volatile software programs, non-volatile computer executable programs and modules. The processor 101 executes various function applications and data processing of the electronic device by running the non-volatile software programs, instructions and units stored in the memory 103, that is, implements the H-bridge circuit control method of the above method embodiments.

[0117] The memory 103 can include a program storage area and a data storage area, wherein the program storage area can store an operating system and at least one application required by a function; the data storage area can store data created according to the use of the electronic device, etc. In addition, the memory 103 can include a high-speed random access memory, and can also include a non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other non-volatile solid-state memory device. In some embodiments, the memory 103 can optionally include a memory remotely arranged with respect to the processor 101, and these remote memories can be connected to the electronic device through a network. Examples of the above network include but are not limited to the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0118] The one or more units are stored in the memory 103, and when executed by the one or more processors 101, the H-bridge circuit control method in any of the above method embodiments is executed.

[0119] The above electronic device can execute the H-bridge circuit control method provided by the embodiments of the present application, and has the corresponding program modules and beneficial effects of the execution method. Technical details not described in detail in the electronic device embodiment can refer to the H-bridge circuit control method provided by the embodiments of the present application.

[0120] In some embodiments of the present application, a switching power supply is also provided, which includes an H-bridge circuit and an electronic device as described in the above embodiments.

[0121] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit them; under the idea of the present application, the technical features in the above examples or different embodiments can also be combined, the steps can be implemented in any order, and there are many other changes of different aspects of the present application as described above. In order to be brief, they are not provided in detail; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method of controlling an H-bridge circuit, the H-bridge circuit comprising a first set of switching transistors and a second set of switching transistors, characterized by, The method comprises the following steps: setting a target state and a target voltage of the H-bridge circuit; the target voltage comprises a voltage amplitude and a voltage polarity; obtaining a duty cycle according to the output voltage and the target voltage; controlling the first switch group to be PWM modulated according to the duty cycle, the target state and the target voltage; the first switch group comprises a first upper bridge arm switch S1 and a first lower bridge arm switch S2; the method comprises the following steps: when the target state is set to be a discharging state and the polarity of the target voltage is positive, the first upper bridge arm switch S1 is used as a BUCK tube, and the conduction time of the first upper bridge arm switch S1 is controlled according to the duty cycle, so as to output the target voltage; when the target state is set to be a discharging state and the polarity of the target voltage is negative, the first lower bridge arm switch S2 is used as a BUCK tube, and the conduction time of the first lower bridge arm switch S2 is controlled according to the duty cycle, so as to output the target voltage; the first upper bridge arm switch S1 and the first lower bridge arm switch S2 adopt a complementary high-frequency switching mode, in which one is used as a main power switch, and the other is used as a freewheeling switch; controlling the second switch group to keep a corresponding conduction or cut-off state according to 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; the second switch group comprises a second upper bridge arm switch S3 and a second lower bridge arm switch S4.

2. The method of claim 1, wherein, The method of obtaining the duty cycle according to the output voltage and the target voltage comprises the following steps: calculating the duty cycle through double-loop control according to the output voltage and the target voltage; the double-loop control comprises a voltage outer loop taking the output voltage and the target voltage as inputs, and a current inner loop taking the output of the voltage outer loop as an input.

3. The method of claim 2, wherein, The method of calculating the duty cycle through double-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; amplitude-limiting the voltage loop output; inputting the amplitude-limited voltage loop output into a second PI controller to obtain the duty cycle.

4. The method of claim 1, wherein, The method of controlling the first switch group to be PWM modulated according to the duty cycle, the target state and the target voltage further comprises the following steps: when the target state is set to be a charging state and the polarity of the target voltage is positive, the first lower bridge arm switch S2 is used as a BOOST tube, the conduction time of the first lower bridge arm switch S2 is controlled according to the duty cycle, and the first upper bridge arm switch S1 is controlled to be a freewheeling tube; when the target state is set to be a charging state and the polarity of the target voltage is negative, the first upper bridge arm switch S1 is used as a BOOST tube, the conduction time of the first upper bridge arm switch S1 is controlled according to the duty cycle, and the first lower bridge arm switch S2 is controlled to be a freewheeling tube.

5. The method of claim 4, wherein, The BOOST tube or the BUCK tube is turned on prior to the freewheeling tube.

6. The method of claim 1, wherein, The second switch tube group comprises a second upper bridge arm switch tube S3 and a second lower bridge arm switch tube S4, and the step of controlling the second switch tube group to keep a corresponding conduction or non-conduction state according to the target state and the target voltage comprises the following steps. When the target state is set to the discharging state and the polarity of the target voltage is positive, the second upper bridge arm switch tube S3 is controlled to keep non-conduction and the second lower bridge arm switch tube S4 is controlled to keep conduction. When the target state is set to the discharging state and the polarity of the target voltage is negative, the second lower bridge arm switch tube S4 is controlled to keep non-conduction and the second upper bridge arm switch tube S3 is controlled to keep conduction.

7. The method of claim 6, wherein, The step of controlling the second switch tube group to keep a corresponding conduction or non-conduction state according to the target state and the target voltage further comprises 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 keep non-conduction and the second lower bridge arm switch tube S4 is controlled to keep conduction. 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 keep non-conduction and the second upper bridge arm switch tube S3 is controlled to keep conduction.

8. An electronic device, comprising: Comprise: at least one processor; at least one network interface, which is in communication connection with the corresponding processor; and, a memory in communication connection with 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, 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 1-7.

9. A switching power supply, characterized by Comprise: an H-bridge circuit; and the electronic device according to claim 8.

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