Bridge circuit control system, power supply module and electric equipment

Abstract

The invention discloses a bridge circuit control system, a power supply module and electric equipment. The bridge circuit control system comprises a bridge circuit, a photoelectric coupler, a signal circuit and a controller. The bridge circuit comprises a first switch and a second switch which are electrically connected, the photoelectric coupler comprises a light-emitting part and a light-operated switch, the light-emitting part is connected with the first switch in parallel, the light-operated switch is located in the light-emitting range of the light-emitting part, and the signal circuit is electrically connected with the light-operated switch and used for sending an indication signal to the controller according to the on-off state of the light-operated switch. The controller is used for controlling a target switch according to the indication signal, and the target switch is the first switch or the second switch. In the invention, the complexity and the element number of the photoelectric coupler and the signal circuit are far less than those of other voltage and current sampling circuits for realizing the same function. Therefore, through a small number of circuit elements, the energy consumption when the bridge circuit switch is turned on can be reduced, and the circuit design complexity can be reduced.

Description

Technical Field

[0001] The present disclosure relates to the field of power electronics technology, and particularly to a bridge circuit control system, a power supply module, and an electrical device. Background Art

[0002] In a bridge circuit, in order to reduce the energy loss caused by the switch when turning on during the commutation of the bridge arm, soft-switching technology has gradually been widely applied. The so-called soft-switching technology means that when the inductor current in the bridge circuit is zero or the voltage across the switch tube to be turned on is zero, the switch tube is turned on to reduce the energy loss caused by the turn-on of the switch tube.

[0003] In the related art, a current sensor is often connected in series on the branch where the switch tube is located, and in cooperation with the subsequent conditioning circuit and comparison circuit, information on the inductor current returning to zero is obtained, so as to turn on the switch tube when the inductor current returns to zero, thereby reducing the switching loss.

[0004] However, in the above structure, a large number of circuit components are required, and the circuit design is relatively complex. Summary of the Invention

[0005] Embodiments of the present disclosure provide a bridge circuit control system, a power supply module, and an electrical device, which can solve the above technical problems existing in the related art. The technical solutions are as follows:

[0006] In a first aspect, a bridge circuit control system is provided. The bridge circuit control system includes a bridge circuit, an optocoupler, a signal circuit, and a controller;

[0007] The bridge circuit includes a first switch and a second switch that are electrically connected;

[0008] The optocoupler includes a light-emitting component and a light-controlled switch. The light-emitting component is connected in parallel with the first switch, and the light-controlled switch is within the light-emitting range of the light-emitting component;

[0009] The signal circuit is electrically connected to the light-controlled switch and is configured to send an indication signal to the controller according to the switch state of the light-controlled switch;

[0010] The controller is configured to control a target switch according to the indication signal, where the target switch is the first switch or the second switch.

[0011] In a possible implementation manner, the light-emitting component is a light-emitting diode. The positive electrode of the light-emitting diode is electrically connected to the drain of the first switch, and the negative electrode of the light-emitting diode is electrically connected to the source of the first switch.

[0012] In a possible implementation, the bridge circuit control system further includes a current-limiting resistor, which is located on the parallel branch of the light-emitting component and is connected in series with the light-emitting component.

[0013] In a possible implementation, the light control switch is a phototransistor.

[0014] In a possible implementation, the signal circuit includes a signal voltage source, a resistor, and a signal terminal;

[0015] The signal voltage source is used to continuously output a high level;

[0016] One end of the resistor is electrically connected to the signal voltage source, and the other end is respectively electrically connected to one end of the light control switch and the signal terminal. The other end of the light control switch is grounded, and the signal terminal is electrically connected to the controller.

[0017] In a possible implementation, the controller is configured to:

[0018] Determine the basic turn-off duration and turn-on duration of the target switch according to the input voltage and output voltage of the bridge circuit;

[0019] Based on the basic turn-off duration and the adjustment duration, determine the turn-off duration of the target switch;

[0020] Control the target switch according to the turn-off duration and the turn-on duration, and adjust the adjustment duration according to the indication signal when the target switch is turned on;

[0021] Wherein, the initial value of the adjustment duration is a specified value.

[0022] In a possible implementation, the controller is configured to:

[0023] Determine the sum of the basic turn-off duration and the adjustment duration as the turn-off duration of the target switch.

[0024] In a possible implementation, the target switch is the first switch;

[0025] The controller is configured to:

[0026] If the switch state of the light control switch indicated by the indication signal when the first switch is turned on is the on state, increase the adjustment duration by the specified value. If the switch state of the light control switch indicated by the indication signal when the first switch is turned on is the off state, keep the adjustment duration unchanged.

[0027] In a possible implementation, the target switch is the second switch;

[0028] The controller is configured to:

[0029] If the switch state of the light control switch indicated by the indication signal when the second switch is on is off, increase the adjustment duration by the specified value; if the switch state of the light control switch indicated by the indication signal when the second switch is on is on, keep the adjustment duration unchanged.

[0030] In a second aspect, a power supply module is provided, which includes the bridge circuit control system provided by the first aspect and its possible implementations.

[0031] In a third aspect, an electrical device is provided, which includes the bridge circuit control system provided by the first aspect and its possible implementations.

[0032] The beneficial effects brought by the technical solutions provided by the present disclosure at least include:

[0033] In the present disclosure, the light-emitting component is connected in parallel with the first switch. That is to say, one end of the light-emitting component is connected between the first switch and the second switch, and is electrically connected to the inductor in the bridge circuit. Therefore, whether the light-emitting component emits light can reflect whether there is a voltage across the first switch, that is, it can reflect the level of the first intermediate node between the first switch and the second switch, and can also reflect whether the current of the inductor is reversed. The switch state of the light control switch is affected by whether the light-emitting component emits light. Therefore, the switch state of the light control switch can reflect whether the current of the inductor has been reversed, and accordingly, the opening of the first switch or the second switch can be controlled, which can reduce the energy consumption when the switch is turned on. The complexity and the number of components of the optocoupler and the signal circuit are much smaller than those of other voltage and current sampling circuits that achieve the same function. Thus, the present disclosure can reduce the energy consumption when the bridge circuit switch is turned on with a small number of circuit components, and can reduce the circuit design complexity.

[0034] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present disclosure. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0036] Figure 1 is a circuit schematic diagram of a DC / DC circuit provided by an embodiment of the present disclosure;

[0037] Figure 2It is a circuit schematic diagram of another DC / DC circuit provided by an embodiment of the present disclosure;

[0038] Figure 3 It is a circuit schematic diagram of an AC / DC circuit provided by an embodiment of the present disclosure;

[0039] Figure 4 It is a circuit schematic diagram of a DC / AC circuit provided by an embodiment of the present disclosure;

[0040] Figure 5 It is a control signal diagram of a DC / DC circuit provided by an embodiment of the present disclosure;

[0041] Figure 6 It is a current cycle schematic diagram of an AC / DC circuit provided by an embodiment of the present disclosure;

[0042] Figure 7 It is a control signal diagram of an AC / DC circuit provided by an embodiment of the present disclosure;

[0043] Figure 8 It is a control signal diagram of an AC / DC circuit provided by an embodiment of the present disclosure;

[0044] Figure 9 It is a current cycle schematic diagram of a DC / AC circuit provided by an embodiment of the present disclosure;

[0045] Figure 10 It is a control signal diagram of a DC / AC circuit provided by an embodiment of the present disclosure;

[0046] Figure 11 It is a control signal diagram of a DC / AC circuit provided by an embodiment of the present disclosure.

[0047] Reference numerals:

[0048] 11. First switch; 12. Second switch; 13. Current-limiting resistor; 14. Inductor; 15. First diode; 16. Second diode; 17. Third diode; 18. Fourth diode; 19. Third switch; 110. Fourth switch;

[0049] 2. Optocoupler; 21. Light-emitting component; 22. Light-controlled switch;

[0050] 3. Signal circuit; 31. Signal voltage source; 32. Resistor; 33. Signal terminal;

[0051] 4. Input source;

[0052] 5. Output source;

[0053] A. First intermediate node;

[0054] B. Second intermediate node. Detailed implementation manners

[0055] To make the objectives, technical solutions and advantages of the present disclosure clearer, the following will further describe the implementation manners of the present disclosure in detail with reference to the accompanying drawings.

[0056] It should be noted that, without conflict, the embodiments in the present disclosure and the features in the embodiments may be combined with each other. The following will detail the present disclosure with reference to the accompanying drawings and in combination with the embodiments.

[0057] An embodiment of the present disclosure provides a bridge circuit control system, as Figure 1 shown. The bridge circuit control system includes a bridge circuit, an optocoupler 2, a signal circuit 3, and a controller. The bridge circuit includes a first switch 11 and a second switch 12 which are electrically connected. The optocoupler 2 includes a light-emitting component 21 and a light-controlled switch 22. The light-emitting component 21 is connected in parallel with the first switch 11. The light-controlled switch 22 is within the light-emitting range of the light-emitting component 21. The signal circuit 3 is electrically connected to the light-controlled switch 22 and is configured to send an indication signal to the controller according to the on / off state of the light-controlled switch 22. The controller is configured to control a target switch according to the indication signal, where the target switch is the first switch 11 or the second switch 12.

[0058] In the embodiment of the present disclosure, the light-emitting component 21 is connected in parallel with the first switch 11. That is to say, one end of the light-emitting component 21 is connected between the first switch 11 and the second switch 12, which is also electrically connected to the inductor 14 in the bridge circuit. Therefore, whether the light-emitting component 21 emits light can reflect whether there is a voltage across the first switch 11, that is, it can reflect the level of the first intermediate node A between the first switch 11 and the second switch 12, and can also reflect whether the current of the inductor 14 has reversed. The on / off state of the light-controlled switch 22 is affected by whether the light-emitting component 21 emits light. Therefore, the on / off state of the light-controlled switch 22 can reflect whether the current of the inductor 14 has reversed, and accordingly, the first switch 11 or the second switch 12 can be controlled to turn on, which can reduce the energy consumption when the switch is turned on. The circuit structure complexity and the number of components of the optocoupler 2 and the signal circuit 3 are much smaller than those of other voltage or current sampling circuits that achieve the same function. Thus, with a small number of circuit components, the energy consumption when the bridge circuit switch is turned on can be reduced, and the circuit design complexity can be lowered.

[0059] Among them, when the bridge circuit enters the dead zone, the current direction of the inductor 3 determines how the first diode 15 and the second diode 16 conduct. When the first diode 15 conducts, the voltage across the first switch 11 is zero. At this time, controlling the first switch 11 to turn on can reduce the energy consumption when the first switch 11 is turned on. When the second diode 16 conducts, the voltage across the second switch 12 is zero. At this time, controlling the second switch 12 to turn on can reduce the energy consumption when the second switch 12 is turned on. The light-emitting component 21 is connected in parallel with the first switch 11. Whether the light-emitting component 21 emits light is determined by the voltage across the first switch 11. Therefore, the switch state of the light control switch 22 can reflect whether the voltage across the first switch 11 is zero (or approximately zero. When the first diode 15 conducts, the voltage across the first switch 11 is approximately zero) or whether it changes from zero to a high level (when the first diode 15 changes from conduction to cut-off and the second diode 16 changes from cut-off to conduction, the voltage across the second switch 12 is approximately zero). The switch state information of the light control switch 22 can be received by the controller, and the controller adjusts the switching moments of the first switch 11 and the second switch 12 to gradually make the circuit work in the zero-voltage turn-on state.

[0060] In addition, the light-emitting component 21 of the optocoupler 2 is partially located on the bridge circuit, and the light control switch 22 is partially located on the signal circuit 3, so as to achieve electrical isolation between the bridge circuit and the signal circuit 3.

[0061] Among them, the inductor 14 is connected in series with the input source 4 or the output source 5, and the first switch 11 and the second switch 12 are on the same bridge arm of the bridge circuit.

[0062] In the embodiments of the present disclosure, the first switch 11 and the second switch 12 are equivalent, and the light-emitting component 21 can also be connected in parallel with the second switch 12. Although Figure 1 、 Figures 3 to 11 both show the scheme where the light-emitting component 21 is connected in parallel with the first switch 11, such a setting is only for the convenience of describing the scheme. The light-emitting component 21 can be connected in parallel with either the first switch 11 or the second switch 12, and the embodiments of the present disclosure do not limit this.

[0063] For example: in Figure 2In the shown circuit diagram, the light-emitting component 21 is connected in parallel with the second switch 12. Whether the light-emitting component 21 emits light is determined by the voltage across the second switch 12. Therefore, the switch state of the light control switch 22 can reflect whether the voltage across the second switch 12 is zero (or approximately zero, when the second diode 16 is conducting, the voltage across the second switch 12 is approximately zero) or whether it changes from zero to a high level (when the second diode 16 changes from conducting to non-conducting and the first diode 15 changes from non-conducting to conducting, the voltage across the first switch 11 is approximately zero). The switch state information of the light control switch 22 can be received by the controller, and the controller adjusts the switching moments of the first switch 11 and the second switch 12, gradually making the circuit work in the zero-voltage turn-on state. In this way, the control of the first switch 11 and the second switch 12 can also be achieved.

[0064] By analogy, in the embodiments of the present disclosure, two optocouplers 2 and signal circuits 3 can also be provided. The light-emitting component 21 of one optocoupler 2 is connected in parallel with the first switch 11, and the light control switch 22 of this optocoupler 2 is located on one of the signal circuits 3; the light-emitting component 21 of the other optocoupler 2 is connected in parallel with the second switch 11, and the light control switch 22 of this optocoupler 2 is located on the other of the signal circuits 3. In this way, the voltages of the first switch 11 and the second switch 12 can be directly detected, rather than indirectly detecting the voltage of one of the switches, so as to improve the accuracy of zero-voltage control.

[0065] The embodiments of the present disclosure do not limit the specific circuit structure of the bridge circuit.

[0066] For example: The bridge circuit can be a DC (Direct Durrent) / DC circuit as shown in Figure 1 or a DC / AC (Alternating Current) circuit as shown in Figure 3 or an AC / DC circuit as shown in Figure 4

[0067] The first switch 11 and the second switch 12 can be, for example but not limited to, MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), IGBT (Insulate-Gate Bipolar Transistor), or GaN (gallium nitride) transistors.

[0068] Among them, the GaN transistor has the characteristics of small turn-off loss and large turn-on loss. The embodiments of the present disclosure can effectively reduce the turn-on loss of the first switch 11. By setting the first switch 11 as a GaN transistor, the switching loss of the first switch 11 can be controlled within a relatively small range.

[0069] The bridge circuit further includes a first diode 15 and a second diode 16. The specific structures of the first diode 15 and the second diode 16 are not limited in the embodiments of the present disclosure.

[0070] For example, both the first diode 15 and the second diode 16 are separate structures. The first diode 15 is connected in parallel with the first switch 11, and the second diode 16 is connected in parallel with the second switch 12.

[0071] For another example, both the first switch 11 and the second switch 12 are MOSFETs. The first diode 15 is the body diode of the first switch 11, and the second diode 16 is the body diode of the second switch 12.

[0072] In some embodiments, the light-emitting component 21 is a light-emitting diode. The positive electrode of the light-emitting diode is electrically connected to the drain of the first switch 11, and the negative electrode of the light-emitting diode is electrically connected to the source of the first switch 11.

[0073] Among them, the light-emitting diode is reverse to the first diode 15. When there is a voltage across the first switch 11, the light-emitting diode conducts. At this time, the light-emitting diode can emit light, so as to irradiate the light-controlled switch 22 and make the light-controlled switch 22 in the on state; when the first switch 11 is in the off state and there is no voltage across it, no current passes through the light-emitting diode, and the light-controlled switch 22 is in the off state; when the first switch 11 is in the on state, there is no voltage across the first switch 11, no current passes through the light-emitting diode, and the light-controlled switch 22 is in the off state.

[0074] In this way, the lighting requirement of the light-emitting component 21 can be realized in a relatively simple manner, thereby reducing the cost of the light-emitting component 21.

[0075] In some embodiments, the bridge circuit control system further includes a current-limiting resistor 13. The current-limiting resistor 13 is located on the parallel branch of the light-emitting component 21 and is connected in series with the light-emitting component 21.

[0076] In this way, it can prevent the current flowing through the light-emitting component 21 from being too large, resulting in overload and damage of the light-emitting component 21, thereby ensuring the service life of the light-emitting component 21.

[0077] In some embodiments, the light-controlled switch 22 is a phototransistor.

[0078] In this way, when the phototransistor receives light, it can absorb the light, thereby generating photo-generated carriers, and through the internal electrical amplification mechanism, generating a photocurrent gain, so as to make the phototransistor conduct. When the phototransistor does not receive light, the phototransistor can block the current.

[0079] The optical transistor can be, for example but not limited to, an optoelectronic device composed of a three-terminal device such as a field-effect transistor.

[0080] Among them, the field-effect optical transistor has a fast response speed (about 50 picoseconds). When the light-emitting component 21 emits light, the optical transistor can respond quickly, so as to ensure the response speed for controlling the first switch 11.

[0081] In some embodiments, the signal circuit 3 includes a signal voltage source 31, a resistor 32, and a signal terminal 33. The signal voltage source 31 is used to continuously output a high level. One end of the resistor 32 is electrically connected to the signal voltage source 31, and the other end is respectively electrically connected to one end of the light control switch 22 and the signal terminal 33. The other end of the light control switch 22 is grounded, and the signal terminal 33 is electrically connected to the controller.

[0082] In this way, when there is a voltage across the first switch 11, the light-emitting component 21 emits light, and the light control switch 22 is turned on. At this time, the resistor 32 will be grounded through the light control switch 22. At this time, the signal terminal 33 is in a low-level state; when the voltage across the first switch 11 drops to a lower range, the light-emitting component 21 does not emit light, and the light control switch 22 is turned off. At this time, the signal terminal 33 is in a high-level state. Thus, when the light control switch 22 switches between the on and off states, the signal terminal 33 will switch between the low-level state and the high-level state. Among them, the signal terminal 33 is electrically connected to the controller, and it is used to output an indication signal, so that the first switch 11 or the second switch 12 can be controlled through the controller.

[0083] In some embodiments, the controller is used for:

[0084] S1. Determine the basic turn-off duration and turn-on duration of the target switch according to the input voltage and output voltage of the bridge circuit;

[0085] S2. Determine the turn-off duration of the target switch based on the basic turn-off duration and the adjustment duration;

[0086] S3. Control the target switch according to the turn-off duration and turn-on duration, and adjust the adjustment duration according to the indication signal when the target switch is turned on;

[0087] Among them, the initial value of the adjustment duration is a specified value.

[0088] In this way, in one control period of the target switch, first determine the basic turn-off duration and turn-on duration of the target switch according to the input voltage and output voltage of the bridge circuit, and determine the turn-off duration of the target switch according to the basic turn-off duration and the adjustment duration. Then, perform control according to the turn-off duration and turn-on duration. During the process of controlling according to the turn-off duration and turn-on duration, if it is determined through the indication signal that there is a large voltage across the target switch when the target switch is turned on, the adjustment duration needs to be adjusted so that the voltage of the target switch can be closer to zero in the next control period. By cycling in this way, the target switch can achieve zero-voltage startup in each control period, thereby enabling the soft-switching technology of the target switch.

[0089] Among them, the initial value of the adjustment duration can be zero.

[0090] In some embodiments, the controller is configured to: determine the sum of the basic turn-off duration and the adjustment duration as the turn-off duration of the target switch.

[0091] In this way, the adjustment process of the turn-off duration of the first switch 11 can be realized in a relatively simple manner.

[0092] In some embodiments, the target switch is the first switch 11. The controller is configured to: if the switch state of the optical control switch 22 indicated by the indication signal when the first switch 11 is turned on is the on state, increase the adjustment duration by a specified value; if the switch state of the optical control switch 22 indicated by the indication signal when the first switch 11 is turned on is the off state, keep the adjustment duration unchanged.

[0093] In this way, the first switch 11 can achieve zero-voltage startup in each control period, thereby enabling the soft-switching technology of the first switch 11.

[0094] Among them, the specified value in "increase the adjustment duration by a specified value" can be a relatively small time value, such as two microseconds, to prevent the adjustment of the adjustment duration from being excessive in a single time, resulting in a significant reduction in the power factor of the bridge circuit.

[0095] In some embodiments, the target switch is the second switch 12. The controller is configured to: if the switch state of the optical control switch 22 indicated by the indication signal when the second switch 12 is turned on is the off state, increase the adjustment duration by a specified value; if the switch state of the optical control switch 22 indicated by the indication signal when the second switch 12 is turned on is the on state, keep the adjustment duration unchanged.

[0096] In this way, the second switch 12 can achieve zero-voltage startup in each control period, thereby enabling the soft-switching technology of the second switch 12.

[0097] Among them, the specified value in "increasing the specified value to the adjustment duration" can be a relatively small time value, such as two microseconds, to prevent excessive adjustment of the adjustment duration at one time, resulting in a significant decrease in the power factor of the bridge circuit.

[0098] Next, the following will be separately Figure 1 , Figure 3 and Figure 4 The three bridge circuits shown in are analyzed.

[0099] (1) Regarding Figure 1 The DC / DC circuit shown

[0100] Figure 1 In the DC / DC circuit shown, the bridge circuit has only one arm. Among them, the input source 4 is connected to the inductor 14, the inductor 14 is connected to the first intermediate node A of the first switch 11 and the second switch 12. The first switch 11 is located between the first intermediate node A and the negative pole of the output source 5, and the second switch 12 is located between the first intermediate node A and the positive pole of the output source 5.

[0101] Figure 5 shows the control diagram of the DC / DC circuit. Among them, iL is the inductor current, G11 is the control signal of the first switch 11. When G11 is at a high potential, the first switch 11 is turned on. When G11 is at a low potential, the first switch 11 is turned off. G12 is the control signal of the second switch 12. When G12 is at a high potential, the second switch 12 is turned on. When G12 is at a low potential, the second switch 12 is turned off. vds is the voltage value of the first intermediate node A of the first switch 11 and the second switch 12. ZCD is an indication signal. When ZCD is at a high level, it means that the optical control switch 22 is in the off state. When ZCD is at a low level, it means that the optical control switch 22 is in the on state.

[0102] As Figure 5 shown, the inductor current will change with the on-off states of the first switch 11 and the second switch 12. Between t 0 -t 1 , G11 is at a high level, G12 is at a low level, the first switch 11 is turned on, the second switch 12 is turned off, and the input source 4 charges the inductor 14, and the inductor current iL rises; between t 2 -t 3 , when G11 is at a low level, G12 is at a high level, the first switch 11 is turned off, the second switch 12 is turned on, the input source 4 and the inductor 14 supply power to the load, and the inductor current iL drops. When the inductor current iL reverses, the voltage vds across the first switch 11 becomes zero. At this time, turning on the first switch 11 can effectively reduce the switching loss of the first switch 11. Among them, t 1 -t 2 and t 3-t 4 They are all dead times set to avoid the simultaneous conduction of the first switch 11 and the second switch 12.

[0103] In this DC / DC circuit, the target switch is always the first switch 11, and the controller is configured to:

[0104] S01. Determine the basic turn-off duration and turn-on duration of the first switch 11 according to the input voltage and output voltage of the bridge circuit;

[0105] S02. Determine the turn-off duration of the first switch 11 based on the basic turn-off duration and the adjustment duration;

[0106] S03. Control the first switch 11 according to the turn-off duration and turn-on duration, and adjust the adjustment duration according to the indication signal when the first switch 11 is turned on. Among them, if the switch state of the optical control switch 22 indicated by the indication signal when the first switch 11 is turned on is the on state, a specified value is added to the adjustment duration. If the switch state of the optical control switch 22 indicated by the indication signal when the first switch 11 is turned on is the off state, the adjustment duration remains unchanged.

[0107] Among them, after the circuit tends to be stable, the turn-off duration of the first switch 11 is maintained at T on .

[0108] (2) Regarding Figure 3 the shown AC / DC circuit

[0109] Figure 3 In the shown AC / DC circuit, the bridge circuit further includes a third diode 17 and a fourth diode 18. Among them, one end of the input source 4 is connected to the inductor 14, the inductor 14 is connected to the first intermediate node A between the first switch 11 and the second switch 12. The first switch 11 is located between the first intermediate node A and the negative pole of the output source 5, and the second switch 12 is located between the first intermediate node A and the positive pole of the output source 5. The other end of the input source 4 is connected to the second intermediate node B between the third diode 17 and the fourth diode 18. The third diode 17 is located between the second intermediate node B and the negative pole of the output source 5, and the fourth diode 18 is located between the second intermediate node B and the positive pole of the output source 5.

[0110] Figure 6 It shows the variation diagram of the voltage of the input source 4 and the inductor current.

[0111] As Figure 7 shown, the inductor current will change with the on / off states of the first switch 11 and the second switch 12. In the positive half cycle of the input source 4, at t 0 -t 1Between them, G11 is at a high level, G12 is at a low level, the first switch 11 is turned on, the second switch 12 is turned off, the inductor 14 is charged, and the inductor current iL rises; at t 2 -t 3 Between them, G11 is at a low level, G12 is at a high level, the first switch 11 is turned off, the second switch 12 is turned on, the inductor 14 discharges, and the inductor current iL drops. When the inductor current iL reverses, the voltage across the first switch 11 becomes zero. At this time, turning on the first switch 11 can effectively reduce the switching loss of the first switch 11. Among them, t 1 -t 2 and t 3 -t 4 are both dead times set to avoid the simultaneous conduction of the first switch 11 and the second switch 12.

[0112] Among them, in the positive half-cycle of the input source 4, the target switch is the first switch 11. Combining Figure 7 as shown, the controller is used for:

[0113] S21. Determine the first basic turn-off duration and the first turn-on duration of the first switch 11 according to the input voltage and the output voltage of the bridge circuit;

[0114] S22. Determine the first turn-off duration of the first switch 11 based on the first basic turn-off duration and the adjustment duration;

[0115] S23. Control the first switch 11 according to the first turn-off duration and the first turn-on duration, and adjust the adjustment duration according to the indication signal when the first switch 11 is turned on. Among them, if the switch state of the optical control switch 22 indicated by the indication signal when the first switch 11 is turned on is the on state, then add a specified value to the adjustment duration. If the switch state of the optical control switch 22 indicated by the indication signal when the first switch 11 is turned on is the off state, then keep the adjustment duration unchanged.

[0116] As Figure 8 shown, in the negative half-cycle of the input source 4, at t 0 -t 1 Between them, G11 is at a low level, G12 is at a high level, the first switch 11 is turned off, the second switch 12 is turned on, the inductor 14 is charged, and the inductor current iL rises; at t 2 -t 3 Between them, G11 is at a high level, G12 is at a low level, the first switch 11 is turned on, the second switch 12 is turned off, the inductor 14 discharges, and the inductor current iL drops. When the inductor current iL reverses, the voltage across the second switch 12 becomes zero. At this time, turning on the second switch 12 can effectively reduce the switching loss of the second switch 12. Among them, t 1 -t 2 and t3 -t 4 They are all dead times set to avoid the simultaneous conduction of the first switch 11 and the second switch 12.

[0117] In the negative half-cycle of the input source 4, the target switch is the second switch 12. Combining Figure 8 as shown, the controller is used for:

[0118] S31. Determine the second basic turn-off duration and the second turn-on duration of the second switch 12 according to the input voltage and the output voltage of the bridge circuit;

[0119] S32. Based on the second basic turn-off duration and the adjustment duration, determine the second turn-off duration of the second switch 12;

[0120] S33. Control the second switch 12 according to the second turn-off duration and the second turn-on duration, and adjust the adjustment duration according to the indication signal when the second switch 12 is turned on. Among them, if the switch state of the light control switch 22 indicated by the indication signal when the second switch 12 is turned on is the off state, increase the adjustment duration by a specified value. If the switch state of the light control switch 22 indicated by the indication signal when the second switch 12 is turned on is the on state, keep the adjustment duration unchanged.

[0121] Among them, after the circuit tends to be stable, in the positive half-cycle of the input source 4, the turn-off duration of the first switch 11 is maintained at T off1 and the turn-on duration is maintained at T on1 . In the negative half-cycle of the input source 4, the turn-off duration of the second switch 12 is maintained at T off2 and the turn-on duration is maintained at T on2 . Among them, T off1 and T off2 can be equal. And in the negative half-cycle and the positive half-cycle of the input source 4, the adjustment durations used by the first switch 11 and the second switch 12 can be the same value.

[0122] (III) Regarding Figure 4 the AC / DC circuit shown

[0123] Figure 4In the AC / DC circuit shown, the bridge circuit further includes a third diode 17, a fourth diode 18, a third switch 19, and a fourth switch 110. The first switch 11 and the second switch 12 are located on one arm of the bridge circuit, the third switch 19 and the fourth switch 110 are located on the other arm of the bridge circuit, the third diode 17 is connected in parallel with the third switch 19, and the fourth diode 18 is connected in parallel with the fourth switch 110. One end of the output source 5 is connected to the inductor 14, the inductor 14 is connected to the first intermediate node A between the first switch 11 and the second switch 12, the first switch 11 is located between the first intermediate node A and the negative pole of the input source 4, the second switch 12 is located between the first intermediate node A and the positive pole of the input source 4, the other end of the output source 5 is connected to the second intermediate node B between the third switch 19 and the fourth switch 110, the third diode 17 is located between the second intermediate node B and the negative pole of the input source 4, and the fourth diode 18 is located between the second intermediate node B and the positive pole of the input source 4.

[0124] Figure 9 The change diagram of the voltage of the input source 4 and the inductor current is shown.

[0125] As Figure 8 shown, in the positive half-cycle of the output source 5, the third switch 19 is always on, the fourth switch 110 is always off. Between t 0 -t 1 , G11 is at a low level, G12 is at a high level, the first switch 11 is off, the second switch 12 is on, the inductor 14 is charged, and the inductor current iL rises; between t 2 -t 3 , G11 is at a high level, G12 is at a low level, the first switch 11 is on, the second switch 12 is off, the inductor 14 is discharged, and the inductor current iL falls. When the inductor current iL reverses, the voltage across the second switch 12 becomes zero. At this time, turning on the second switch 12 can effectively reduce the switching loss of the second switch 12. Among them, t 1 -t 2 and t 3 -t 4 are both dead times set to avoid the simultaneous conduction of the first switch 11 and the second switch 12.

[0126] Among them, in the positive half-cycle of the output source 5, the target switch is the second switch 12. As shown in combination with Figure 10 , the controller is used for:

[0127] S41. Determine the second basic turn-off duration and the second turn-on duration of the second switch 12 according to the input voltage and the output voltage of the bridge circuit;

[0128] S42. Determine the second turn-off duration of the second switch 12 based on the second basic turn-off duration and the adjustment duration;

[0129] S43. Control the second switch 12 according to the second turn-off duration and the second turn-on duration, and adjust the adjustment duration according to the indication signal when the second switch 12 is turned on. Among them, if the switch state of the light control switch 22 indicated by the indication signal when the second switch 12 is turned on is the on state, increase the adjustment duration by a specified value; if the switch state of the light control switch 22 indicated by the indication signal when the second switch 12 is turned on is the off state, keep the adjustment duration unchanged.

[0130] As Figure 11 shown, in the negative half-cycle of the output source 5, the fourth switch 110 is always on, the third switch 19 is always off. At t 0 -t 1 between, G11 is at a high level, G12 is at a low level, the first switch 11 is on, the second switch 12 is off, the inductor 14 is charged, and the inductor current iL rises; at t 2 -t 3 between, G11 is at a low level, G12 is at a high level, the first switch 11 is off, the second switch 12 is on, the inductor 14 discharges, and the inductor current iL drops. When the inductor current iL reverses, the voltage vds across the first switch 11 becomes zero. At this time, turning on the first switch 11 can effectively reduce the switching loss of the first switch 11. Among them, t 1 -t 2 and t 3 -t 4 are both dead times set to avoid simultaneous conduction of the first switch 11 and the second switch 12.

[0131] In the negative half-cycle of the output source 5, the target switch is the first switch 11. As shown in Figure 11 , the controller is used for:

[0132] S51. Determine the first basic turn-off duration and the first turn-on duration of the first switch 11 according to the input voltage and the output voltage of the bridge circuit;

[0133] S52. Based on the first basic turn-off duration and the adjustment duration, determine the first turn-off duration of the first switch 11;

[0134] S53. Control the first switch 11 according to the first turn-off duration and the first turn-on duration, and adjust the adjustment duration according to the indication signal when the first switch 11 is turned on. Among them, if the switch state of the light control switch 22 indicated by the indication signal when the first switch 11 is turned on is the on state, increase the adjustment duration by a specified value; if the switch state of the light control switch 22 indicated by the indication signal when the first switch 11 is turned on is the off state, keep the adjustment duration unchanged.

[0135] Among them, after the circuit tends to be stable, in the negative half-cycle of the output source 5, the off-time of the first switch 11 is maintained at T off3 and the on-time is maintained at T on3 . In the positive half-cycle of the output source 5, the off-time of the second switch 12 is maintained at T off4 and the on-time is maintained at T on4 . Among them, T off3 and T off4 can be equal. And in the negative half-cycle and positive half-cycle of the output source 5, the adjustment time used by the first switch 11 and the second switch 12 can be the same value.

[0136] Based on the same concept, an embodiment of the present disclosure also provides a power supply module, which includes the bridge circuit control system mentioned above.

[0137] Based on the same concept, an embodiment of the present disclosure also provides an electrical device, which includes the bridge circuit control system mentioned above.

[0138] Among them, the electrical device can be, for example but not limited to, a UPS (Uninterruptible Power Supply), a charging pile or an electric fan.

[0139] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present disclosure. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or their combinations.

[0140] Unless otherwise specifically stated, the relative arrangements, numerical expressions and values of the components and steps set forth in these embodiments do not limit the scope of the present disclosure. At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn in actual proportional relationships. Technologies, methods and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the said technologies, methods and devices should be regarded as part of the specification. In all the examples shown and discussed here, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that: similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0141] In the description of the present disclosure, it should be understood that the orientation or positional relationship indicated by orientation words such as "front, rear, upper, lower, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom", etc. is usually based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present disclosure and simplifying the description. Without contrary explanation, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the protection scope of the present disclosure; the orientation words "inside, outside" refer to the inside and outside relative to the contour of each component itself.

[0142] For ease of description, spatial relative terms such as "above", "over", "on the upper surface", "upper" etc. may be used here to describe the spatial positional relationship of one device or feature to other devices or features as shown in the figures. It should be understood that the spatial relative terms are intended to encompass different orientations in use or operation in addition to the orientation depicted in the figures for the device. For example, if the device in the figures is inverted, the device described as "above" or "over" other devices or structures will then be positioned "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both the orientations of "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and corresponding interpretations should be made for the spatial relative descriptions used herein.

[0143] In addition, it should be noted that the use of words such as "first", "second", etc. to limit components is only for the convenience of distinguishing the corresponding components. Without additional statement, the above words have no special meaning. Therefore, it should not be construed as a limitation on the protection scope of the present disclosure.

[0144] The above are only the preferred embodiments of the present disclosure and are not used to limit the present disclosure. For those skilled in the art, the present disclosure can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure shall be included within the protection scope of the present disclosure.

Claims

1. A bridge circuit control system, characterized in that: The bridge circuit control system comprises a bridge circuit, a photoelectric coupler (2), a signal circuit (3) and a controller; The bridge circuit comprises a first switch (11) and a second switch (12) which are electrically connected; The photoelectric coupler (2) comprises a light-emitting element (21) and a light-controlled switch (22), the light-emitting element (21) being connected in parallel with the first switch (11), and the light-controlled switch (22) being located within the light-emitting range of the light-emitting element (21); The signal circuit (3) is electrically connected to the light-controlled switch (22), and is used to send an indication signal to the controller according to the switch state of the light-controlled switch (22); The controller is used for controlling a target switch according to the indication signal, wherein the target switch is the first switch (11) or the second switch (12).

2. The bridge circuit control system according to claim 1, characterized in that: The light-emitting element (21) is a light-emitting diode, the anode of the light-emitting diode is electrically connected to the drain of the first switch (11), and the cathode of the light-emitting diode is electrically connected to the source of the first switch (11).

3. The bridge circuit control system according to claim 2, characterized in that: The bridge circuit control system further comprises a current limiting resistor (13), wherein the current limiting resistor (13) is located on a parallel branch of the light-emitting element (21) and is connected in series with the light-emitting element (21).

4. The bridge circuit control system according to claim 1, characterized in that: The light-controlled switch (22) is a phototransistor.

5. The bridge circuit control system according to claim 4, characterized in that: The signal circuit (3) comprises a signal voltage source (31), a resistor (32) and a signal terminal (33); The signal voltage source (31) is used to continuously output a high level; One end of the resistor (32) is electrically connected to the signal voltage source (31), and the other end is electrically connected to one end of the light-controlled switch (22) and the signal terminal (33), respectively; the other end of the light-controlled switch (22) is grounded, and the signal terminal (33) is electrically connected to the controller.

6. The bridge circuit control system according to claim 1, characterized in that: The controller is used to: Determining a basic off-time and on-time of a target switch according to an input voltage and an output voltage of the bridge circuit; Determining the off time of the target switch based on the basic off time and the adjustment time; Controlling the target switch according to the off time and the on time, and adjusting the adjustment time according to an indication signal when the target switch is turned on; The initial value of the adjustment duration is a specified value.

7. The bridge circuit control system according to claim 6, characterized in that: The controller is used to: The sum of the basic off-time and the adjusted time is determined as the off-time of the target switch.

8. The bridge circuit control system according to claim 6, characterized in that: The target switch is the first switch (11); The controller is used to: If the switch state of the light-controlled switch (22) indicated by the indication signal when the first switch (11) is turned on is an on state, the adjustment time length is increased by the specified value; if the switch state of the light-controlled switch (22) indicated by the indication signal when the first switch (11) is turned on is an off state, the adjustment time length is kept unchanged.

9. The bridge circuit control system according to claim 6, characterized in that: The target switch is the second switch (12); The controller is used to: If the switch state of the light-controlled switch (22) indicated by the indication signal when the second switch (12) is turned on is an off state, the adjustment time length is increased by the specified value; if the switch state of the light-controlled switch (22) indicated by the indication signal when the second switch (12) is turned on is an on state, the adjustment time length is kept unchanged.

10. A power module, characterized in that: The power module includes the bridge circuit control system according to any one of claims 1-9.

11. An electrical device, characterized in that: The electrical equipment includes the bridge circuit control system described in any one of claims 1-9.

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