Voltage conversion circuit, photovoltaic junction box and photovoltaic module

Abstract

The embodiment of the utility model provides a voltage conversion circuit, a photovoltaic junction box and a photovoltaic module. According to the voltage conversion circuit, a first isolation transformation module outputs a first voltage signal in a first half cycle based on a first control signal of a control module; the first isolation switch module is based on the control of the control module, conducts a first connection between the first isolation transformation module and the first filtering module in a first half period, and cuts off the first connection in a second half period. The second isolation transformation module outputs a second voltage signal in a second half cycle based on a second control signal of the control module; the second isolation switch module conducts a second connection between the second isolation transformation module and the second filtering module in a second half period based on the control of the control module; the filtering module is used for filtering the voltage signal to obtain an AC voltage signal.

Description

Technical Field

[0001] The utility model relates to the field of power transformation, in particular to a voltage conversion circuit, a photovoltaic junction box and a photovoltaic component. Background Art

[0002] Existing photovoltaic grid-connected inverters usually boost the DC power output by photovoltaic modules into DC high voltage, then chop it into a 50HZ sinusoidal fundamental wave through an H-bridge, and then transmit it to the grid through an inductor-capacitor-inductor (LCL) filter circuit; the inverter H-bridge on the high-voltage side has the risk of direct short circuit of the Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) in the same bridge arm, and there is a disadvantage of high-frequency switching loss and high-frequency electromagnetic radiation when the four MOSFETs of the H-bridge are hard-switched. Utility Model Content

[0003] The embodiments of the present disclosure provide a voltage conversion circuit, a photovoltaic junction box and a photovoltaic module.

[0004] According to a first aspect of an embodiment of the present disclosure, a voltage conversion circuit is provided, wherein the voltage conversion circuit comprises:

[0005] A detection module, configured to detect a circuit parameter, wherein the circuit parameter includes at least one of the following: a first half cycle and a second half cycle of the alternating current, wherein the first half cycle is different from the second half cycle;

[0006] A control module, used to control at least one of the first isolation transformer module, the first isolation switch module, the second isolation transformer module and the second isolation switch module according to the circuit parameters;

[0007] The first isolation transformer module is configured to output a first voltage signal in the first half cycle according to an input DC voltage signal based on a first control signal of the control module;

[0008] The first isolation switch module is used to conduct the first connection between the first isolation transformer module and the first filter module in the first half cycle based on the control of the control module, and to disconnect the first connection in the second half cycle;

[0009] The first filtering module is used for, in the first half cycle, inputting a first voltage signal through the first connection, filtering the first voltage signal to obtain a first AC voltage signal, and outputting the first AC voltage signal to the AC power grid;

[0010] The second isolation transformer module is configured to output a second voltage signal in the second half cycle according to the input DC voltage signal based on the second control signal of the control module;

[0011] The second isolation switch module is used for switching on the second connection between the second isolation transformer module and the second filter module in the second half cycle based on the control of the control module, and switching off the second connection in the first half cycle;

[0012] The second filtering module is used to input a second voltage signal through the second connection and filter the second voltage signal to obtain a second AC voltage signal in the second half cycle, and output the second AC voltage signal to the AC power grid.

[0013] In some embodiments, the first isolation transformer module includes: a first full-bridge circuit, a first transformer and a first full-wave rectifier circuit;

[0014] The first full-bridge circuit is used for converting the DC voltage signal into a first square wave voltage signal in the first half cycle based on the first sinusoidal pulse width modulation signal of the control module, and inputting the first square wave voltage signal into the first primary winding of the first transformer, wherein the first control signal includes the first sinusoidal pulse width modulation signal;

[0015] The first full-wave rectifier circuit is used for full-wave rectifying the first induced voltage signal output by the first secondary winding of the first transformer inducing the first square wave voltage to obtain the first voltage signal;

[0016] The second isolation transformer module comprises: a second full-bridge circuit, a second transformer and a second full-wave rectifier circuit;

[0017] The second full-bridge circuit is used to convert the DC voltage signal into a second square wave voltage signal in the second half cycle based on the second sinusoidal pulse width modulation signal of the control module, and input the second square wave voltage signal to the second primary winding of the second transformer; the first control signal includes the second sinusoidal pulse width modulation signal;

[0018] The second full-wave rectifier circuit is used to full-wave rectify the second induced voltage signal output by the second secondary winding of the second transformer inducing the second square wave voltage to obtain the second voltage signal.

[0019] In some embodiments, the first transformer and the second transformer are the same transformer, the first primary winding and the second primary winding are the same primary winding, the first full-bridge circuit and the second full-bridge circuit are the same full-bridge circuit; the first transformer includes the first secondary winding and the second secondary winding,

[0020] The first full-bridge circuit is used to convert the DC voltage signal into a first square wave voltage signal in the first half cycle based on the first sinusoidal pulse width modulation signal, and input the first square wave voltage signal to the first primary winding; and to convert the DC voltage signal into a second square wave voltage signal in the second half cycle based on the second sinusoidal pulse width modulation signal, and input the second square wave voltage signal to the first primary winding;

[0021] The first full-wave rectifier circuit is used for full-wave rectifying the first induced voltage signal output by the first secondary winding inducing the first square wave voltage to obtain the first voltage signal;

[0022] The second full-wave rectifier circuit is used to full-wave rectify the second induced voltage signal output by the second secondary winding inducing the second square wave voltage to obtain the second voltage signal.

[0023] In some embodiments, the first isolation transformer module includes: a first flyback isolation circuit composed of a first switch tube, a third transformer and a first rectifier diode, wherein the first switch tube is connected to a first end of a third primary winding of the third transformer, a second end of the third primary winding inputs the DC voltage signal, and the first rectifier diode is connected to a third secondary winding of the third transformer; the first flyback isolation circuit converts the DC voltage signal into the first voltage signal in the first half cycle based on a third sinusoidal pulse width modulation signal input by the control module to the first switch tube;

[0024] The second isolation transformer module comprises: a second flyback isolation circuit composed of a second switch tube, a fourth transformer and a second rectifier diode, wherein the second switch tube is connected to a first end of a fourth primary winding of the fourth transformer, the second end of the fourth primary winding inputs the DC voltage signal, the second rectifier diode is connected to a fourth secondary winding of the fourth transformer, and the second flyback isolation circuit converts the DC voltage signal into the second voltage signal in the second half cycle based on a fourth sinusoidal pulse width modulation signal input by the control module to the second switch tube;

[0025] The first control signal includes the third sinusoidal pulse width modulation signal and the fourth sinusoidal pulse width modulation signal.

[0026] In some embodiments, the first isolation switch module includes: a third flyback isolation circuit composed of a third switch tube, a fifth transformer and a third rectifier diode, and a fourth switch tube, wherein the third switch tube is connected to a first end of a fifth primary winding of the fifth transformer, a second end of the fifth primary winding inputs the DC voltage signal, the third rectifier diode is connected to a fifth secondary winding of the fifth transformer, and the third flyback isolation circuit outputs a first isolation switch signal to the fourth switch tube based on a first switch signal input by the control module to the third switch tube, so as to turn on or off the first connection;

[0027] The second isolation switch module includes: a fourth flyback isolation circuit composed of a fifth switch tube, a sixth transformer and a fourth rectifier diode, and a sixth switch tube, wherein the fifth switch tube is connected to the first end of the sixth primary winding of the sixth transformer, the second end of the sixth primary winding is input with the DC voltage signal, the fourth rectifier diode is connected to the sixth secondary winding of the sixth transformer, and the fourth flyback isolation circuit outputs a second isolation switch signal to the sixth switch tube based on the second switch signal input by the control module to the fifth switch tube to turn on or off the second connection.

[0028] In some embodiments, the voltage conversion circuit further includes: a first voltage stabilization module, configured to perform voltage stabilization processing on the DC voltage signal input to the second end of the fifth primary winding and the second end of the sixth primary winding.

[0029] In some embodiments, the voltage conversion circuit further includes at least one of the following: a second voltage stabilization module, a third voltage stabilization module;

[0030] The second voltage stabilizing module is connected between the third rectifier diode and the fourth switch tube, and is used for performing voltage stabilization processing on the first isolation switch signal;

[0031] The third voltage stabilizing module is connected between the fourth rectifier diode and the sixth switch tube, and is used for performing voltage stabilizing processing on the second isolation switch signal.

[0032] In some embodiments, the first filtering module includes a first inductor-capacitor LC filtering circuit;

[0033] The second filtering module includes a second inductor-capacitor (LC) filtering circuit.

[0034] In some embodiments, the first inductor of the first LC filter circuit and the second inductor of the second LC filter circuit are the same inductor.

[0035] In some embodiments, the circuit parameter further includes at least one item: a current value corresponding to the first AC voltage signal, a current value corresponding to the second AC voltage signal;

[0036] A control module for at least one of the following:

[0037] Based on the current value corresponding to the first AC voltage signal, adjusting the duty cycle of the first control signal to adjust the first voltage signal;

[0038] Based on the current value corresponding to the second AC voltage signal, the duty cycle of the second control signal is adjusted to adjust the second voltage signal.

[0039] According to a second aspect of an embodiment of the present disclosure, a photovoltaic junction box is provided, comprising the voltage conversion circuit described in the first aspect.

[0040] According to a third aspect of the embodiments of the present disclosure, a photovoltaic assembly is provided, comprising the voltage conversion circuit described in the first aspect, or the photovoltaic junction box described in the second aspect.

[0041] According to a fourth aspect of an embodiment of the present disclosure, a voltage conversion circuit control method is provided, characterized in that it is applied to the voltage conversion circuit described in the first aspect, and the method includes:

[0042] Acquire a circuit parameter detected by a detection module, wherein the circuit parameter includes one of the following: a first half cycle and a second half cycle of the alternating current, wherein the first half cycle is different from the second half cycle;

[0043] determining circuit parameters for the first half cycle;

[0044] Sending a first control signal to control the first isolation transformer module to output a first voltage signal according to the input DC voltage signal in the first half cycle;

[0045] Controlling the first isolation switch module to conduct the first connection between the first isolation transformer module and the first filter module, wherein the first filter module is used to input a first voltage signal through the first connection in the first half cycle, filter the first voltage signal to obtain a first AC voltage signal, and output the first AC voltage signal to the AC power grid;

[0046] Control the second isolation switch module to shut down the second connection between the second isolation transformer module and the second filter module, wherein the second filter module is used to input a second voltage signal through the second connection in the second half cycle, filter the second voltage signal to obtain a second AC voltage signal, and output the second AC voltage signal to the AC power grid.

[0047] In some embodiments, the method further comprises:

[0048] Determine the circuit parameters for the second half cycle,

[0049] sending a second control signal to control the second isolation transformer module to output a second voltage signal according to the input DC voltage signal in the second half cycle,

[0050] Controlling the first isolating switch module to disconnect the first connection;

[0051] The second isolating switch module is controlled to conduct the second connection.

[0052] In some embodiments, the method further comprises:

[0053] The circuit parameters also include at least one item: the current value corresponding to the first AC voltage signal, the current value corresponding to the second AC voltage signal;

[0054] The method further comprises at least one of the following:

[0055] Based on the current value corresponding to the first AC voltage signal, adjusting the duty cycle of the first control signal to adjust the first voltage signal;

[0056] Based on the current value corresponding to the second AC voltage signal, the duty cycle of the second control signal is adjusted to adjust the second voltage signal.

[0057] According to a fifth aspect of the embodiments of the present disclosure, an electronic device is provided, wherein the electronic device:

[0058] one or more processors;

[0059] Wherein, the processor is used to call instructions so that the electronic device executes the voltage conversion circuit control method described in the fourth aspect.

[0060] According to a sixth aspect of an embodiment of the present disclosure, a storage medium is proposed, wherein the storage medium stores instructions, and when the instructions are executed on an electronic device, the electronic device executes the voltage conversion circuit control method described in the fourth aspect.

[0061] The voltage conversion circuit provided by the embodiment of the present disclosure is that the control module obtains the first half cycle and the second half cycle of the detection module detecting the alternating current, the first isolation transformer module outputs the first voltage signal in the first half cycle based on the first control signal of the control module; the first isolation switch module conducts the first connection between the first isolation transformer module and the first filter module in the first half cycle based on the control of the control module, and shuts off the first connection in the second half cycle; the second isolation transformer module outputs the second voltage signal in the second half cycle based on the second control signal of the control module; the second isolation switch module conducts the second connection between the second isolation transformer module and the second filter module in the second half cycle based on the control of the control module; the filter module is used to filter the voltage signal to obtain the AC voltage signal. On the one hand, the voltage conversion circuit can realize voltage conversion and synchronization with the AC power grid based on the monitoring of the AC power cycle by the detection module, and meet the grid-connected power generation requirements. On the other hand, the first isolation transformer module and the second isolation transformer module only need to transform the half-amplitude voltage of the AC power, which can improve the transformation efficiency and reduce energy waste. On the other hand, the isolation transformer module isolates the AC power grid when the isolation transformer module is not output, reduces the probability of the isolation transformer module being damaged by the AC backflow, and improves the circuit safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 is a schematic structural diagram of a voltage conversion circuit according to an exemplary embodiment;

[0063] Figure 2 is a schematic structural diagram of a voltage conversion circuit according to an exemplary embodiment;

[0064] Figure 3 is a schematic structural diagram of a voltage conversion circuit according to an exemplary embodiment;

[0065] Figure 4 is a schematic structural diagram of a voltage conversion circuit according to an exemplary embodiment;

[0066] Figure 5 is a schematic structural diagram of a voltage conversion circuit according to an exemplary embodiment;

[0067] Figure 6 is a schematic structural diagram of a voltage conversion circuit according to an exemplary embodiment;

[0068] Figure 7 is a schematic structural diagram of a voltage conversion circuit according to an exemplary embodiment;

[0069] Figure 8 is a schematic structural diagram of a voltage conversion circuit according to an exemplary embodiment;

[0070] Fig. 9 is a schematic structural diagram of a voltage conversion circuit according to an exemplary embodiment;

[0071] Fig.10 is a schematic structural diagram of a voltage conversion circuit according to an exemplary embodiment;

[0072] Fig.11 is a schematic structural diagram of a voltage conversion circuit according to an exemplary embodiment;

[0073] Fig.12 is a schematic structural diagram of a voltage conversion circuit according to an exemplary embodiment;

[0074] Fig.13 is a schematic structural diagram of a voltage conversion circuit according to an exemplary embodiment;

[0075] Fig.14 is a flow chart of a voltage conversion circuit control method according to an exemplary embodiment;

[0076] Fig.15 is a flow chart of a voltage conversion circuit control method according to an exemplary embodiment;

[0077] Fig.16 is a flow chart of a voltage conversion circuit control method according to an exemplary embodiment;

[0078] Fig.17 is a schematic structural diagram of a voltage conversion circuit according to an exemplary embodiment;

[0079] Fig.18 is a schematic structural diagram of a voltage conversion circuit according to an exemplary embodiment;

[0080] Fig.19 is a flow chart of a voltage conversion circuit control method according to an exemplary embodiment;

[0081] Fig. 20 The diagram is a schematic structural diagram of an electronic device according to an exemplary embodiment. DETAILED DESCRIPTION

[0082] In order to make the technical solutions and beneficial effects of the utility model more obvious and easy to understand, the following is a detailed description by listing specific embodiments. The drawings are not necessarily drawn to scale, and local features may be enlarged or reduced to more clearly show the details of the local features; unless otherwise defined, the technical and scientific terms used herein have the same meanings as those in the technical field to which this application belongs.

[0083] The embodiments of the present disclosure are not exhaustive, but are only illustrative of some embodiments, and are not intended to be a specific limitation on the scope of protection of the present disclosure. In the absence of contradiction, each step in a certain embodiment can be implemented as an independent embodiment, and the steps can be arbitrarily combined. For example, a solution after removing some steps in a certain embodiment can also be implemented as an independent embodiment, and the order of the steps in a certain embodiment can be arbitrarily exchanged. In addition, the optional implementation methods in a certain embodiment can be arbitrarily combined; in addition, the embodiments can be arbitrarily combined, for example, some or all of the steps of different embodiments can be arbitrarily combined, and a certain embodiment can be arbitrarily combined with the optional implementation methods of other embodiments.

[0084] In each embodiment of the present disclosure, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between the embodiments are consistent and can be referenced to each other, and the technical features in different embodiments can be combined to form a new embodiment based on their internal logical relationships.

[0085] The terms used in the embodiments of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure.

[0086] In the embodiments of the present disclosure, unless otherwise specified, elements expressed in the singular form, such as "a", "an", "the", "above", "said", "aforementioned", "this", etc., may mean "one and only one", or "one or more", "at least one", etc. For example, when using articles such as "a", "an", "the" in English in translation, the noun after the article may be understood as a singular expression or a plural expression.

[0087] In the embodiments of the present disclosure, “plurality” refers to two or more.

[0088] In some embodiments, the terms "at least one", "one or more", "a plurality of", "multiple", etc. can be used interchangeably.

[0089] In some embodiments, "at least one of A and B", "A and / or B", "A in one case, B in another case", "A in one case, B in another case", etc., may include the following technical solutions according to the situation: in some embodiments, A (A is executed independently of B); in some embodiments, B (B is executed independently of A); in some embodiments, execution is selected from A and B (A and B are selectively executed); in some embodiments, A and B (both A and B are executed). When there are more branches such as A, B, C, etc., the above is also similar.

[0090] In some embodiments, the recording method of "A or B" may include the following technical solutions according to the situation: in some embodiments, A (A is executed independently of B); in some embodiments, B (B is executed independently of A); in some embodiments, execution is selected from A and B (A and B are selectively executed). When there are more branches such as A, B, C, etc., the above is also similar.

[0091] The prefixes such as "first" and "second" in the embodiments of the present disclosure are only used to distinguish different description objects, and do not constitute restrictions on the position, order, priority, value or content of the description objects. The statement of the description object refers to the description in the context of the claims or embodiments, and should not constitute redundant restrictions due to the use of prefixes. For example, if the description object is a "field", the ordinal number before the "field" in the "first field" and the "second field" does not limit the position or order between the "fields", and the "first" and "second" do not limit whether the "fields" they modify are in the same message, nor do they limit the order of the "first field" and the "second field". For another example, if the description object is a "level", the ordinal number before the "level" in the "first level" and the "second level" does not limit the priority between the "levels". For another example, the numerical value of the description object is not limited by the ordinal number, and can be one or more. Taking the "first device" as an example, the numerical value of the "device" can be one or more. In addition, the objects modified by different prefixes may be the same or different. For example, if the description object is "device", then the "first device" and the "second device" may be the same device or different devices, and their types may be the same or different. For another example, if the description object is "information", then the "first information" and the "second information" may be the same information or different information, and their contents may be the same or different.

[0092] In some embodiments, “including A”, “comprising A”, “used to indicate A”, and “carrying A” can be interpreted as directly carrying A or indirectly indicating A.

[0093] In some embodiments, terms such as “…”, “determine…”, “in the case of…”, “at the time of…”, “when…”, “if…”, “if…”, etc. can be used interchangeably.

[0094] In some embodiments, terms such as "greater than", "greater than or equal to", "not less than", "more than", "more than or equal to", "not less than", "higher than", "higher than or equal to", "not lower than", and "above" can be replaced with each other, and terms such as "less than", "less than or equal to", "not greater than", "less than", "less than or equal to", "no more than", "lower than", "lower than or equal to", "not higher than", and "below" can be replaced with each other.

[0095] In some embodiments, devices, etc. can be interpreted as physical or virtual, and their names are not limited to the names recorded in the embodiments. Terms such as "device", "equipment", "device", "circuit", "network element", "node", "function", "unit", "section", "system", "network", "chip", "chip system", "entity", and "subject" can be used interchangeably.

[0096] In addition, each element, each row, or each column in the table of the embodiments of the present disclosure may be implemented as an independent embodiment, and the combination of any elements, any rows, and any columns may also be implemented as an independent embodiment.

[0097] The four MOS of the inverter H-bridge will cause high-frequency switching loss and high-frequency electromagnetic radiation when switching. Especially in the low voltage and low current stage of each sine cycle, the input voltage is first increased to high voltage and then converted to low voltage, which results in serious energy waste.

[0098] The inverter H-bridge consists of two left and right bridge arms, each of which consists of upper and lower bridge arm MOS. The lower bridge arm MOS controls the negative end of the high voltage, and the upper bridge arm MOS controls the positive end of the high voltage. In this way, the upper and lower bridge arm MOS are not at the same potential. Especially when driving the upper bridge arm, a voltage pump is required to boost the drive voltage to exceed the DC bus voltage, which increases the driving cost. In addition, the upper and lower bridge arm MOS are respectively connected to the positive and negative ends of the DC high voltage, and there is a risk of direct short circuit. Then, the high-voltage side H-bridge controls at least a pair of left and right MOS tubes to operate simultaneously at a time, which makes the control complicated.

[0099] Figure 1 1 is a voltage conversion circuit 100 according to an embodiment of the present disclosure. Figure 1 As shown, the voltage conversion circuit 100 includes:

[0100] A detection module 110, configured to detect a circuit parameter, wherein the circuit parameter includes at least one of the following: a first half cycle and a second half cycle of the alternating current, wherein the first half cycle is different from the second half cycle;

[0101] The control module 120 is used to control at least one of the first isolation transformer module 130, the first isolation switch module 140, the second isolation transformer module 160 and the second isolation switch module 170 according to the circuit parameters;

[0102] The first isolation transformer module 130 is configured to output a first voltage signal in the first half cycle according to an input DC voltage signal based on a first control signal of the control module 120;

[0103] The first isolation switch module 140 is used to switch on the first connection between the first isolation transformer module 130 and the first filter module 150 in the first half cycle based on the control of the control module 120, and to switch off the first connection in the second half cycle;

[0104] The first filtering module 150 is used for, in the first half cycle, inputting a first voltage signal through the first connection, filtering the first voltage signal to obtain a first AC voltage signal, and outputting the first AC voltage signal to the AC power grid;

[0105] The second isolation transformer module 160 is configured to output a second voltage signal in the second half cycle according to the input DC voltage signal based on the second control signal of the control module 120;

[0106] The second isolation switch module 170 is used to conduct the second connection between the second isolation transformer module 160 and the second filter module 180 in the second half cycle based on the control of the control module 120, and to shut down the second connection in the first half cycle;

[0107] The second filtering module 180 is used to input a second voltage signal through the second connection and filter the second voltage signal to obtain a second AC voltage signal in the second half cycle, and output the second AC voltage signal to the AC power grid.

[0108] Here, the voltage conversion circuit 100 can be used for photovoltaic power generation and grid connection. The voltage conversion circuit 100 can convert the DC voltage signal generated by photovoltaic power generation into an AC voltage signal of an AC grid. Here, the AC power can be industrial frequency AC power, including 220V / 50Hz AC power, but is not limited thereto.

[0109] In a possible implementation, the first half cycle may be a positive half cycle of the alternating current, and the second half cycle may be a negative half cycle of the alternating current.

[0110] In a possible implementation, the first half cycle may be a negative half cycle of the alternating current, and the second cycle may be a positive half cycle of the alternating current.

[0111] The detection module 110 can be used to detect the zero-crossing point of the alternating current. For example, the detection module 110 may include a rectifier diode and a current-limiting resistor connected in series with the rectifier diode, and the zero-crossing point of the alternating current is determined by the current of the alternating current through the current-limiting resistor. The detection module 110 determines whether the alternating current is in a positive half-cycle or a negative half-cycle by means of half-wave rectification of the alternating current, that is, determines the first half-cycle and / or the second half-cycle.

[0112] In a possible implementation, the detection module 110 detects the first half cycle and the second half cycle including at least one of the following:

[0113] The detection module 110 detects the starting position and the ending position of the first half cycle;

[0114] The detection module 110 detects a start position and an end position of the second half cycle.

[0115] In a possible implementation, the control module 120 may determine the second half cycle based on the determined first half cycle, for example, determining the end position and the start position of the second half cycle based on the start position and the end position of the first half cycle, respectively.

[0116] In a possible implementation, the control module 120 may determine the first half cycle based on the determined second half cycle, for example, determining the end position and the start position of the first half cycle based on the start position and the end position of the second half cycle, respectively.

[0117] In one possible implementation, different circuit parameters may be indicated by different electrical signals. For example, the control module 120 may indicate the starting position of the first half cycle by a rising edge, and indicate the ending position of the first half cycle and the starting position of the second half cycle by a falling edge, and so on.

[0118] In a possible implementation, the detection module 110 is connected to the control module 120 , and the detection module 110 sends the circuit parameters to the control module 120 through the connection with the control module 120 .

[0119] The control module 120 may enable at least one of the first isolation transformer module 130, the first isolation switch module 140, the second isolation transformer module 160 and the second isolation switch module 170 based on the first half cycle and / or the second half cycle. For example, the control module 120 may send a first control signal in the first half cycle to enable the first isolation transformer module 130 and control the first isolation switch module 140 to output a first voltage signal, and send a second control signal in the second half cycle to enable the second isolation transformer module 160 and control the second isolation switch module 170 to output a second voltage signal.

[0120] In a possible implementation, the first voltage signal may be a DC voltage signal, and the second voltage signal may be a DC voltage signal.

[0121] In a possible implementation, the first AC voltage signal may be a voltage signal within a half cycle of AC power, the first AC voltage signal may be a DC voltage signal, and the second voltage signal may be a DC voltage signal.

[0122] In a possible implementation, the first control signal may be an enable signal for switching the output of the first isolation transformer module 130 .

[0123] In a possible implementation, the first control signal may be used to adjust the output voltage value of the first isolation transformer module 130. In a possible implementation, the second control signal may be an enable signal used to switch the output of the second isolation transformer module 160.

[0124] In a possible implementation, the second control signal may be used to adjust the output voltage value of the second isolation transformer module 160 .

[0125] In a possible implementation, the control module 120 may include a controller and a peripheral circuit. The control module 120 may provide a control logic signal, and the peripheral circuit may provide level adaptation. For example, the control module 120 may provide a control logic signal for a switch tube, and the peripheral circuit may control the logic signal to perform level conversion (such as boosting, etc.) to control the switch tube.

[0126] The isolation transformer module (the first isolation transformer module 130 and the second isolation transformer module 160) can achieve isolation between the DC voltage signal and the voltage signal (the first voltage signal and the second voltage signal) through an isolation circuit, such as a transformer. The isolation transformer module can achieve voltage regulation through a transformer, for example, by stepping up or down the DC voltage signal through a transformer to obtain a voltage signal (the first voltage signal and the second voltage signal).

[0127] In a possible implementation, the isolation transformer module may include a chopper circuit to chop the DC voltage signal, and then obtain the voltage signal (the first voltage signal and the second voltage signal) through isolation transformer transformation and rectification.

[0128] The voltage value of the first voltage signal can meet the requirement of the first AC voltage signal of the first half-cycle AC power, and the voltage value of the second voltage signal can meet the requirement of the second AC voltage signal of the second half-cycle AC power. For example, the DC voltage signal can be chopped using an SPWM signal to obtain the first voltage signal or the second voltage signal, and the first voltage signal or the second voltage signal is filtered by the first filtering module 150 and the second filtering module 180 respectively to obtain the first AC voltage signal and the second AC voltage signal that meet the AC power requirement.

[0129] In a possible implementation manner, the voltage polarities of the first AC voltage signal and the second AC voltage signal are opposite.

[0130] The first isolation transformer module 130 and the second isolation transformer module 160 are respectively only responsible for half a cycle voltage output of the alternating current. Compared with one isolation transformer module that needs to be responsible for the entire cycle voltage output of the alternating current, the output voltage difference between the first isolation transformer module 130 and the second isolation transformer module 160 is smaller, reducing the risk of voltage difference breakdown caused by the large output voltage difference.

[0131] The first isolating switch module 140 can be used to switch the first AC voltage input to the first filter module 150; the second isolating switch module 170 can be used to switch the second AC voltage input to the second filter module 180. In the first half cycle, the first isolating switch module 140 conducts the first connection, so that the first voltage signal is input to the first filter module 150 for filtering to obtain the first AC voltage signal input to the AC power grid; at the same time, the second isolating switch module 170 disconnects the second connection, reducing the situation where the AC power grid electrical signal is backflowed into the second isolation transformer module 160, and reducing the risk of the second isolation transformer module 160 being broken down by the AC power grid electrical signal. In the second half cycle, the second isolating switch module 170 conducts the second connection, so that the second voltage signal is input to the second filter module 180 for filtering to obtain the second AC voltage signal input to the AC power grid; at the same time, the first isolating switch module 140 disconnects the first connection, reducing the situation where the AC power grid electrical signal is backflowed into the first isolation transformer module 130, and reducing the risk of the first isolation transformer module 130 being broken down by the AC power grid electrical signal.

[0132] In this way, the first isolation transformer module 130 and the second isolation transformer module 160 are respectively used for half-cycle voltage output of the alternating current, and the first isolation switch module 140 and the second isolation switch module 170 are used to switch the first voltage signal and the second voltage signal respectively. The voltage conversion circuit 100 provided by the embodiment of the present disclosure obtains the first half cycle and the second half cycle of the alternating current detected by the detection module 110 by the control module 120, and the first isolation transformer module 130 outputs the first voltage signal in the first half cycle based on the first control signal of the control module 120; the first isolation switch module 140, based on the control of the control module 120, turns on the first connection between the first isolation transformer module 130 and the first filter module 150 in the first half cycle, and turns off the first connection in the second half cycle; the second isolation transformer module 160, based on the second control signal of the control module 120, outputs the second voltage signal in the second half cycle; the second isolation switch module 170, based on the control of the control module 120, turns on the second connection between the second isolation transformer module 160 and the second filter module 180 in the second half cycle; the filter module is used to filter the voltage signal to obtain an AC voltage signal. On the one hand, the voltage conversion circuit 100 can realize voltage conversion and synchronization with the AC power grid based on the monitoring of the AC power cycle by the detection module 110, so as to meet the grid-connected power generation demand. On the other hand, the first isolation transformer module 130 and the second isolation transformer module 160 only need to transform the voltage of half the amplitude of the AC power, which can improve the transformation efficiency and reduce energy waste. On the other hand, the isolation transformer module isolates the AC power grid when the isolation transformer module is not output, reducing the probability of the isolation transformer module being damaged by the backflow of AC power and improving the circuit safety.

[0133] In one embodiment, Figure 2 As shown, the first isolation transformer module 130 includes: a first full-bridge circuit 131, a first transformer 132 and a first full-wave rectifier circuit 133;

[0134] The first full-bridge circuit 131 is used for converting the DC voltage signal into a first square wave voltage signal in the first half cycle based on the first sinusoidal pulse width modulation signal of the control module 120, and inputting the first square wave voltage signal to the first primary winding of the first transformer 132, wherein the first control signal includes the first sinusoidal pulse width modulation signal;

[0135] The first full-wave rectifier circuit 133 is used for full-wave rectifying the first induced voltage signal output by the first secondary winding of the first transformer 132 inducing the first square wave voltage to obtain the first voltage signal;

[0136] like Figure 3As shown, the second isolation transformer module 160 includes: a second full-bridge circuit 161, a second transformer 162 and a second full-wave rectifier circuit 163;

[0137] The second full-bridge circuit 161 is used to convert the DC voltage signal into a second square wave voltage signal in the second half cycle based on the second sinusoidal pulse width modulation signal of the control module 120, and input the second square wave voltage signal to the second primary winding of the second transformer 162; the first control signal includes the second sinusoidal pulse width modulation signal;

[0138] The second full-wave rectifier circuit 163 is used to perform full-wave rectification on the second induced voltage signal output by the second secondary winding of the second transformer 162 inducing the second square wave voltage to obtain the second voltage signal.

[0139] Specifically, Figure 4 As shown, the first full-bridge circuit 131 may include an H-bridge composed of four switch tubes Q1, Q2, Q3 and Q4. Among them, Q1 and Q4 form a current path, and Q3 and Q2 form a current path. The first transformer 132 may include a transformer T1. The first full-wave rectifier circuit 133 includes four rectifier diodes D1, D2, D3 and D4, among which D1 and D3 form a current path, and D2 and D4 form a current path.

[0140] In the first half cycle, the control module 120 controls Q1, Q2, Q3 and Q4 to input a first square wave voltage signal to the first primary winding of the first transformer 132 through a first sinusoidal pulse width modulation signal. The first square wave voltage signal can generate a current in one or two directions in the first primary winding of the first transformer 132, thereby inducing a first induced voltage signal in the first secondary winding of the first transformer 132. The induced current of the first secondary winding of the first transformer 132 can be in one direction or in two directions. The first sinusoidal pulse width modulation signals applied by the control module 120 to Q1, Q2, Q3 and Q4 are different.

[0141] The first full-wave rectifier circuit 133 rectifies the induced current of the first secondary winding of the first transformer 132. Figure 4 As shown, a positive first voltage signal is generated at the N poles of D1 and D4.

[0142] In the first half cycle, the first isolation switch module 140 conducts the first connection, and the first filter module 150 filters the first voltage signal to obtain a first AC voltage signal.

[0143] The second full-bridge circuit 161 may include an H-bridge composed of four switch tubes Q5, Q6, Q7 and Q8. Among them, Q5 and Q8 form a current path, and Q7 and Q6 form a current path. The second transformer 162 may include a transformer T2. The second full-wave rectifier circuit 163 includes four rectifier diodes D5, D6, D7 and D8, among which D5 and D7 form a current path, and D6 and D8 form a current path.

[0144] In the second half cycle, the control module 120 controls Q5, Q6, Q7 and Q8 to input a second square wave voltage signal to the first primary winding of the second transformer 162 through a second sinusoidal pulse width modulation signal. The second square wave voltage signal can generate a current in one or two directions in the first primary winding of the second transformer 162, thereby inducing a second induced voltage signal in the first secondary winding of the second transformer 162. The induced current of the first secondary winding of the second transformer 162 can be in one direction or in two directions. The first sinusoidal pulse width modulation signals applied by the control module 120 to Q5, Q6, Q7 and Q8 are different.

[0145] The second full-wave rectifier circuit 163 rectifies the induced current of the first secondary winding of the second transformer 162. Figure 4 As shown, a positive second voltage signal is generated at the N poles of D5 and D7.

[0146] In the second half cycle, the second isolation switch module 170 conducts the second connection, and the second filtering module 180 filters the second voltage signal to obtain a second AC voltage signal.

[0147] In a possible implementation, the first transformer 132 and the second transformer 162 may be used for voltage boosting or voltage reduction.

[0148] In one possible implementation, in the first half cycle, the control module 120 can turn off the second full-bridge circuit 161Q5, Q6, Q7 and Q8, so that no induced electromotive force is generated on the second transformer 162, that is, in the first half cycle, the second isolation transformer module 160 does not generate a second voltage signal.

[0149] In one possible implementation, in the second half cycle, the control module 120 can turn off the first full-bridge circuit 131Q1, Q2, Q3 and Q4, so that no induced electromotive force is generated on the first transformer 132, that is, in the first half cycle, the first isolation transformer module 130 does not generate a first voltage signal.

[0150] In this way, by generating a square wave voltage signal through a full-bridge circuit and performing full-bridge rectification, the conversion efficiency of the DC voltage signal into a voltage signal (a first voltage signal and a second voltage signal) can be improved, thereby reducing energy waste.

[0151] In some embodiments, the first transformer 132 and the second transformer 162 are the same transformer, the first primary winding and the second primary winding are the same primary winding, the first full-bridge circuit 131 and the second full-bridge circuit 161 are the same full-bridge circuit; the first transformer 132 includes the first secondary winding and the second secondary winding,

[0152] The first full-bridge circuit 131 is configured to convert the DC voltage signal into a first square wave voltage signal in the first half cycle based on the first sinusoidal pulse width modulation signal, and input the first square wave voltage signal to the first primary winding; and to convert the DC voltage signal into a second square wave voltage signal in the second half cycle based on the second sinusoidal pulse width modulation signal, and input the second square wave voltage signal to the first primary winding;

[0153] The first full-wave rectifier circuit 133 is used for full-wave rectifying the first induced voltage signal output by the first secondary winding inducing the first square wave voltage to obtain the first voltage signal;

[0154] The second full-wave rectifier circuit 163 is used to perform full-wave rectification on the second induced voltage signal output by the second secondary winding inducing the second square wave voltage to obtain the second voltage signal.

[0155] Specifically, the first full-bridge circuit 131 and the second full-bridge circuit 161 can work only in the first half cycle and the second half cycle respectively, so only one full-bridge circuit can be used to work in the first half cycle and the second half cycle, and the first transformer 132 can have two secondary windings, which are used to output the first voltage signal and the second voltage signal in the first half cycle and the second half cycle respectively. The first connection and the second connection are conducted through the first isolation switch module 140 and the second isolation switch module 170.

[0156] like Figure 5 As shown, the first full-bridge circuit 131 may include an H-bridge composed of four switch tubes Q1, Q2, Q3 and Q4. Among them, Q1 and Q4 form a current path, and Q3 and Q2 form a current path. The first transformer 132 may include a transformer T1. The first transformer 132 includes a first secondary winding T1-A and a second secondary winding T1-B. The first full-wave rectifier circuit 133 includes four rectifier diodes D1, D2, D3 and D4, among which D1 and D3 form a current path, and D2 and D4 form a current path. The second full-wave rectifier circuit 163 includes four rectifier diodes D5, D6, D7 and D8, among which D5 and D7 form a current path, and D6 and D8 form a current path.

[0157] In the first half cycle, the control module 120 controls Q1, Q2, Q3 and Q4 to input the first square wave voltage signal to the first primary winding of the first transformer 132 through the first sinusoidal pulse width modulation signal. The first square wave voltage signal can generate a current in one or two directions in the first primary winding of the first transformer 132, thereby inducing a first induced voltage signal in the first secondary winding T1-A of the first transformer 132. The induced current of the first secondary winding T1-A of the first transformer 132 can be in one direction or in two directions. Among them, the first sinusoidal pulse width modulation signals applied by the control module 120 to Q1, Q2, Q3 and Q4 are different. The first full-wave rectifier circuit 133 rectifies the induced current of the first secondary winding T1-A of the first transformer 132. A positive first voltage signal is generated at the N poles of D1 and D4. The first isolation switch module 140 conducts the first connection, and the first filter module 150 filters the first voltage signal to obtain a first AC voltage signal.

[0158] In the second half cycle, the control module 120 controls Q1, Q2, Q3 and Q4 to input a second square wave voltage signal to the first primary winding of the first transformer 132 through a second sinusoidal pulse width modulation signal. The second square wave voltage signal can generate a current in one or two directions in the first primary winding of the first transformer 132, thereby inducing a second induced voltage signal in the second secondary winding T1-B of the first transformer 132. The induced current of the second secondary winding T1-B of the first transformer 132 can be in one direction or in two directions. Among them, the second sinusoidal pulse width modulation signal applied by the control module 120 to Q1, Q2, Q3 and Q4 is different. The second full-wave rectifier circuit 163 rectifies the induced current of the second secondary winding T1-B of the first transformer 132. A positive second voltage signal is generated at the N poles of D5 and D7. The second isolation switch module 170 conducts the second connection, and the second filter module 180 filters the second voltage signal to obtain a second AC voltage signal.

[0159] In this way, the number of full-bridge circuits and transformers can be reduced, the circuit complexity can be reduced, and the cost can be reduced.

[0160] In some embodiments, Figure 6As shown, the first isolation transformer module 130 includes: a first flyback isolation circuit composed of a first switch tube 134, a third transformer 135 and a first rectifier diode 136, wherein the first switch tube 134 is connected to a first end of a third primary winding of the third transformer 135, a second end of the third primary winding inputs the DC voltage signal, and the first rectifier diode 136 is connected to a third secondary winding of the third transformer 135; the first flyback isolation circuit converts the DC voltage signal into the first voltage signal in the first half cycle based on the third sinusoidal pulse width modulation signal input by the control module 120 to the first switch tube 134;

[0161] like Figure 7 As shown, the second isolation transformer module 160 includes: a second flyback isolation circuit consisting of a second switch tube 164, a fourth transformer 165, and a second rectifier diode 166, wherein the second switch tube 164 is connected to a first end of a fourth primary winding of the fourth transformer 165, the second end of the fourth primary winding inputs the DC voltage signal, the second rectifier diode 166 is connected to a fourth secondary winding of the fourth transformer 165, and the second flyback isolation circuit converts the DC voltage signal into the second voltage signal in the second half cycle based on the fourth sinusoidal pulse width modulation signal input by the control module 120 to the second switch tube 164;

[0162] The first control signal includes the third sinusoidal pulse width modulation signal and the fourth sinusoidal pulse width modulation signal.

[0163] Here, the first switch tube 134 and the first rectifier diode 136 can be connected to the opposite ends of the third transformer 135. The first switch tube 134 switches the current flowing out of the third primary winding of the third transformer 135 according to the third sinusoidal pulse width modulation signal, thereby generating an induced electromotive force in the third secondary winding of the third transformer 135, which is rectified by the first rectifier diode 136 to obtain a first voltage signal.

[0164] Specifically, Figure 8 As shown, the first switch tube 134Q1 and the first rectifier diode 136D1 can be connected to the opposite terminals of the third transformer 135T1. In the first half cycle, Q1 switches the current flowing out of the third primary winding of T1 according to the third sinusoidal pulse width modulation signal, thereby generating an induced electromotive force at the third secondary winding of T1, which is rectified by the first rectifier diode 136D1 to obtain a first voltage signal.

[0165] In the first half cycle, the first isolation switch module 140 conducts the first connection, and the first filter module 150 filters the first voltage signal to obtain a first AC voltage signal.

[0166] Here, the second switch tube 164 and the second rectifier diode 166 can be connected to the opposite-name terminals of the fourth transformer 165. The second switch tube 164 switches the current flowing out of the fourth primary winding of the fourth transformer 165 according to the fourth sinusoidal pulse width modulation signal, thereby generating an induced electromotive force at the fourth secondary winding of the fourth transformer 165, which is rectified by the second rectifier diode 166 to obtain a second voltage signal.

[0167] Specifically, Figure 8 As shown, the second switch tube 164Q5 and the second rectifier diode 166D5 can be connected to the opposite-name terminals of the fourth transformer 165T2. In the second half cycle, Q5 switches the current flowing out of the fourth primary winding of T2 according to the fourth sinusoidal pulse width modulation signal, thereby generating an induced electromotive force at the fourth secondary winding of T2, which is rectified by D5 to obtain a second voltage signal

[0168] In the second half cycle, the second isolation switch module 170 conducts the second connection, and the second filtering module 180 filters the second voltage signal to obtain a second AC voltage signal.

[0169] When the voltage value of the input voltage (ie, the DC voltage signal) is low, the flyback circuit has a higher conversion efficiency and can reduce energy waste.

[0170] In some embodiments, Fig. 9 As shown, the first isolation switch module 140 includes: a third flyback isolation circuit composed of a third switch tube 141, a fifth transformer 142 and a third rectifier diode 143, and a fourth switch tube 144, wherein the third switch tube 141 is connected to the first end of the fifth primary winding of the fifth transformer 142, the second end of the fifth primary winding is input with the DC voltage signal, the third rectifier diode 143 is connected with the fifth secondary winding of the fifth transformer 142, and the third flyback isolation circuit outputs a first isolation switch signal to the fourth switch tube 144 based on the first switch signal input to the third switch tube 141 by the control module 120, so as to turn on or off the first connection;

[0171] like Fig.10As shown, the second isolation switch module 170 includes: a fourth flyback isolation circuit composed of a fifth switch tube 171, a sixth transformer 172 and a fourth rectifier diode 173, and a sixth switch tube 174, wherein the fifth switch tube 171 is connected to the first end of the sixth primary winding of the sixth transformer 172, the second end of the sixth primary winding is input with the DC voltage signal, the fourth rectifier diode 173 is connected to the sixth secondary winding of the sixth transformer 172, and the fourth flyback isolation circuit outputs a second isolation switch signal to the sixth switch tube 174 based on the second switch signal input by the control module 120 to the fifth switch tube 171, so as to turn on or off the second connection.

[0172] Specifically, Figure 4 As shown, the third switch tube 141Q12 and the third rectifier diode 143D9 can be connected to the fifth primary winding and the fifth secondary winding of the fifth transformer 142T3, respectively. Q12 switches the outflow current of the fifth primary winding of T3 according to the first switch signal, thereby generating an induced electromotive force in the fifth secondary winding of T3, that is, generating a first isolation switch signal, and the first isolation switch signal is used to control the conduction or closure of the fourth switch tube 144Q9, thereby turning on or off the first connection. Since the first switch signal and the first isolation switch signal are isolated by the fifth transformer 142T3, the situation of AC power backflow in the AC power grid damaging the control module 120 is reduced. In the first half cycle, the first isolation switch signal is used to control the conduction of the fourth switch tube 144Q9, that is, to turn on the first connection. In the second half cycle, the first isolation switch signal is used to control the closure of the fourth switch tube 144Q9, that is, to turn off the first connection.

[0173] The fifth switch tube 171Q11 and the fourth rectifier diode 173D10 can be connected to the sixth primary winding and the sixth secondary winding of the sixth transformer 172T4, respectively. Q11 switches the outflow current of the fifth primary winding of T4 according to the second switch signal, thereby generating an induced electromotive force in the sixth secondary winding of T4, that is, generating a second isolation switch signal, and the second isolation switch signal is used to control the conduction or closure of the sixth switch tube 174Q10, thereby turning on or off the second connection. Since the second switch signal and the second isolation switch signal are isolated by the sixth transformer 172T4, the situation of AC power backflow in the AC power grid damaging the control module 120 is reduced. In the second half cycle, the second isolation switch signal is used to control the conduction of the sixth switch tube 174Q10, that is, to turn on the second connection. In the second half cycle, the second isolation switch signal is used to control the closing of the sixth switch tube 174Q10, that is, to turn off the first connection.

[0174] like Figure 4As shown, the negative output end of the first isolation transformer module 130 is connected to the positive output end of the second isolation transformer module 160 through the first isolation switch module 140 (controlled by the second isolation switch module), and is output to the first end of the AC power grid through the filter module, and the positive output end of the first isolation transformer module 130 is connected to the AC power grid and the negative output end of the second isolation transformer module and is output to the second end of the AC power grid, thereby realizing power supply to the AC power grid.

[0175] In some embodiments, the voltage conversion circuit 100 further includes: a first voltage stabilization module, configured to perform voltage stabilization processing on the DC voltage signal input to the second end of the fifth primary winding and the second end of the sixth primary winding.

[0176] In a possible implementation, the first voltage stabilizing module may include: a first resistor connected in series with the first input terminal of the DC voltage signal of the fifth primary winding, a voltage stabilizing diode connected in parallel with the first input terminal, and a first capacitor connected in parallel with the first input terminal, wherein the first resistor is used to limit the current entering the voltage stabilizing diode.

[0177] In a possible implementation, the first voltage stabilizing module may include: a second resistor connected in series with the second input terminal of the DC voltage signal of the sixth primary winding, a voltage stabilizing diode connected in parallel with the second input terminal, and a second capacitor connected in parallel with the second input terminal, wherein the second resistor is used to limit the current entering the voltage stabilizing diode.

[0178] In a possible implementation, the first input terminal of the DC voltage signal of the fifth primary winding is connected to the second input terminal of the DC voltage signal of the sixth primary winding, and the first input terminal and the second input terminal may share a first voltage stabilization module.

[0179] In a possible implementation, the voltage regulator diode may be a Zener diode.

[0180] Specifically, Figure 4 As shown, the first input terminal of the DC voltage signal of the fifth primary winding T3 of the fifth transformer 142T3 is connected to the second input terminal of the DC voltage signal of the sixth primary winding of the sixth transformer 172T4, and the first voltage stabilizing module may include: a first resistor R3 connected in series with the first input terminal (i.e., connected in series with the second input terminal), a voltage stabilizing diode ZD3 connected in parallel with the first input terminal (i.e., connected in parallel with the second input terminal), and a first capacitor C5 connected in parallel with the first input terminal (i.e., connected in parallel with the second input terminal).

[0181] The first voltage stabilization module can reduce fluctuations in the DC voltage signal and improve the stability of the output first isolation switch signal and the second isolation switch signal.

[0182] In some embodiments, the voltage conversion circuit 100 further includes at least one of the following: a second voltage stabilization module, a third voltage stabilization module;

[0183] The second voltage stabilizing module is connected between the third rectifier diode 143 and the fourth switch tube 144, and is used to perform voltage stabilization processing on the first isolation switch signal;

[0184] The third voltage stabilizing module is connected between the fourth rectifier diode 173 and the sixth switch tube 174 and is used for performing voltage stabilization processing on the second isolation switch signal.

[0185] Here, the second voltage stabilizing module is connected in parallel with the first isolation switch signal input terminal of the fourth switch tube 144 to stabilize the first isolation switch signal.

[0186] The third voltage stabilizing module is connected in parallel with the second isolation switch signal input terminal of the sixth switch tube 174 to stabilize the second isolation switch signal.

[0187] Specifically, Figure 4 As shown, the second voltage stabilizing module includes: a resistor R1, a capacitor C3 and a voltage stabilizing diode ZD1 connected in parallel with the first isolation switch signal input terminal of the fourth switch tube 144. The third voltage stabilizing module includes: a resistor R2, a capacitor C4 and a voltage stabilizing diode ZD2 connected in parallel with the third isolation switch signal input terminal of the sixth switch tube 174.

[0188] In some embodiments, the first filtering module 150 includes a first inductor-capacitor LC filtering circuit;

[0189] The second filtering module 180 includes a second inductor-capacitor (LC) filtering circuit.

[0190] Here, an LC filter circuit may be used to filter the first voltage signal and the second voltage signal respectively.

[0191] In some embodiments, the first inductor of the first LC filter circuit and the second inductor of the second LC filter circuit are the same inductor.

[0192] Since the first isolation transformer module 130 outputs the first voltage signal in the first half cycle and the second isolation transformer module 160 outputs the second voltage signal in the second half cycle, the first voltage signal h and the second voltage signal output by the first isolation transformer module 130 and the second isolation transformer module 160 will not exist at the same time. Therefore, an inductor can be shared for filtering to reduce circuit cost.

[0193] like Figure 4As shown, the negative output end of the first isolation transformer module 130 is connected to one end of the inductor L1 through the first isolation switch module 140 and the positive output end of the second isolation transformer module 160 (controlled by the second isolation switch module), and the other end of L1 is provided with capacitors C2 and C3; L1 combines with C2 to filter the first voltage signal, and L1 combines with C3 to filter the second voltage signal.

[0194] In some embodiments, the circuit parameter further includes at least one item: a current value corresponding to the first AC voltage signal, a current value corresponding to the second AC voltage signal;

[0195] The control module 120 is configured to:

[0196] Based on the current value corresponding to the first AC voltage signal, adjusting the duty cycle of the first control signal to adjust the first voltage signal;

[0197] Based on the current value corresponding to the second AC voltage signal, the duty cycle of the second control signal is adjusted to adjust the second voltage signal.

[0198] Depending on the load of the AC power grid, the current value of the first AC voltage signal and the current value of the second AC voltage signal may vary, thereby affecting the voltage value of the first AC voltage signal and the voltage value of the second AC voltage signal.

[0199] The first control signal may include a sinusoidal pulse width modulation signal, and the detection module 110 may detect the current value of the first AC voltage signal by connecting a detection resistor in series to the first AC voltage signal output terminal, etc. The control module 120 may adjust the first AC voltage signal by adjusting the duty cycle of the sinusoidal pulse width modulation signal.

[0200] The second control signal may include a sinusoidal pulse width modulation signal, and the detection module 110 may detect the current value of the second AC voltage signal by connecting a detection resistor in series to the second AC voltage signal output terminal, etc. The control module 120 may adjust the second AC voltage signal by adjusting the duty cycle of the sinusoidal pulse width modulation signal.

[0201] By adjusting the duty cycle of the sinusoidal pulse width modulation signal, the output energy of the first isolation transformer module 130 and the second isolation transformer module 160 can be adjusted to meet different load requirements.

[0202] Fig.11 A photovoltaic junction box is shown according to an embodiment of the present disclosure. Fig.11 As shown, the voltage conversion circuit 100 includes:

[0203] Figures 1 to 10 The voltage conversion circuit 100 disclosed in any embodiment. The voltage conversion circuit 100 is as follows Figures 1 to 10Any embodiment has been described and will not be repeated here.

[0204] Fig.12 A photovoltaic module according to an embodiment of the present disclosure is shown. Fig.12 As shown, the photovoltaic module includes: photovoltaic battery group and Figures 1 to 10 The voltage conversion circuit 100 disclosed in any embodiment. The battery pack is used to supply power to the voltage conversion circuit 100. The voltage conversion circuit 100 is as follows: Figures 1 to 10 Any embodiment has been described and will not be repeated here.

[0205] Fig.13 A photovoltaic module according to an embodiment of the present disclosure is shown. Fig.13 As shown, the photovoltaic module includes: photovoltaic battery group and Fig.11 The photovoltaic junction box disclosed in any embodiment includes: Figures 1 to 10 The voltage conversion circuit 100 disclosed in any embodiment. The battery pack is used to supply power to the voltage conversion circuit 100. The voltage conversion circuit 100 is as follows: Figures 1 to 10 Any embodiment has been described and will not be repeated here.

[0206] Fig.14 A voltage conversion circuit 100 control method according to an embodiment of the present disclosure is applied to Figure 1 and Fig.13 The voltage conversion circuit 100 disclosed in any embodiment, such as Fig.14 As shown, the voltage conversion circuit 100 control method includes:

[0207] Step 1401: Acquire circuit parameters detected by the detection module 110, wherein the circuit parameters include one of the following: a first half cycle and a second half cycle of the alternating current, wherein the first half cycle is different from the second half cycle;

[0208] Step 1402: Determine circuit parameters for the first half cycle;

[0209] Step 1403: Send a first control signal to control the first isolation transformer module 130 to output a first voltage signal according to the input DC voltage signal in the first half cycle;

[0210] Step 1404: Control the first isolation switch module 140 to conduct the first connection between the first isolation transformer module 130 and the first filter module 150, wherein the first filter module 150 is used to input a first voltage signal through the first connection in the first half cycle, filter the first voltage signal to obtain a first AC voltage signal, and output the first AC voltage signal to the AC power grid;

[0211] Step 1405: Control the second isolating switch module 170 to cut off the second connection between the second isolation transformer module 160 and the second filtering module 180, wherein the second filtering module 180 is used to input a second voltage signal through the second connection in the second half cycle, filter the second voltage signal to obtain a second AC voltage signal, and output the second AC voltage signal to the AC power grid.

[0212] In some embodiments, the method of this embodiment may be executed by the control module 120 in the voltage conversion circuit 100 .

[0213] In some embodiments, the method of this embodiment may be executed by a controller included in the control module 120 in the voltage conversion circuit 100 .

[0214] The detection module 110 detects the circuit parameters in the following manner: Figures 1 to 10 Any embodiment described above will not be repeated here.

[0215] The control module 120 may first be initialized and start acquiring circuit parameters.

[0216] Here, determining the first half cycle may include determining the positive zero crossing point of the alternating current; determining the second half cycle may include determining the negative zero crossing point of the alternating current. Alternatively, determining the first half cycle may include determining the negative zero crossing point of the alternating current; determining the second half cycle may include determining the positive zero crossing point of the alternating current.

[0217] The control module 120 determines that it has entered the first half cycle, and can control the first isolation transformer module 130 to output the first voltage signal through the first control signal. The first isolation transformer module 130 outputs the first voltage signal as shown in FIG. Figures 1 to 10 Any embodiment described above will not be repeated here.

[0218] The control module 120 determines that the first half cycle has begun, and can control the first isolation switch module 140 to conduct the first connection, and the first filter module 150 filters the first voltage signal to obtain a first AC voltage signal output to the AC power grid.

[0219] The control module 120 determines that it has entered the first half cycle and can control the second isolation switch module 170 to disconnect the second connection to reduce the risk of the second isolation transformer module 160 being broken down due to the backflow of AC power from the AC grid into the second isolation transformer module 160 .

[0220] Here, step 1403 to step 1405 are executed in no particular order. For example, step 1404 and step 1405 may be executed first, and then step 1403; or step 1405 may be executed first, then step 1403, and finally step 1404, but the present invention is not limited thereto.

[0221] Fig.15 A voltage conversion circuit 100 control method according to an embodiment of the present disclosure is applied to Figure 1 and Fig.13 The voltage conversion circuit 100 disclosed in any embodiment, such as Fig.15 As shown, the voltage conversion circuit 100 control method includes:

[0222] Step 1501: Determine circuit parameters for the second half cycle;

[0223] Step 1502: Send a second control signal to control the second isolation transformer module 160 to output a second voltage signal according to the input DC voltage signal in the second half cycle;

[0224] Step 1503: controlling the first isolating switch module 140 to disconnect the first connection;

[0225] Step 1504: Control the second isolation switch module 170 to conduct the second connection.

[0226] The control module 120 determines that it has entered the second half cycle, and can control the second isolation transformer module 160 to output a second voltage signal through a second control signal. The second isolation transformer module 160 outputs a second voltage signal such as Figures 1 to 10 Any embodiment described will not be repeated here.

[0227] The control module 120 determines that the second half cycle has begun, and can control the second isolation switch module 170 to conduct the second connection, and the second filter module 180 filters the second voltage signal to obtain a second AC voltage signal output to the AC power grid.

[0228] The control module 120 determines that it has entered the second half cycle, and can control the first isolation switch module 140 to disconnect the first connection, thereby reducing the risk of the first isolation transformer module 130 being broken down due to the AC power of the AC power grid flowing back into the first isolation transformer module 130 .

[0229] Here, step 1502 to step 1504 are executed in no particular order. For example, step 1503 and step 1504 may be executed first, and then step 1502; or step 1504 may be executed first, then step 1503, and finally step 1502, but the present invention is not limited thereto.

[0230] In a possible implementation, the control module 120 may be set to be timing based on the first half cycle duration and / or the second half cycle duration, and the control module 120 may set the first control signal and / or the second control signal based on the first half cycle duration and / or the second half cycle duration. For example, the first control signal and the second control signal may include a sinusoidal pulse width modulation signal, and the control module 120 may set the sinusoidal pulse width modulation signal duty cycle based on the first half cycle duration and / or the second half cycle duration to adjust the output of the first isolation transformer module 130 and the second isolation transformer module 160.

[0231] Fig.16 A voltage conversion circuit 100 control method according to an embodiment of the present disclosure is applied to Figure 1 and Fig.13 The voltage conversion circuit 100 disclosed in any embodiment, such as Fig.16 As shown,

[0232] The circuit parameters also include at least one item: the current value corresponding to the first AC voltage signal, the current value corresponding to the second AC voltage signal;

[0233] The voltage conversion circuit 100 control method includes at least one of the following:

[0234] Step 1601: Based on the current value corresponding to the first AC voltage signal, adjust the duty cycle of the first control signal to adjust the first voltage signal;

[0235] Step 1602: Based on the current value corresponding to the second AC voltage signal, adjust the duty cycle of the second control signal to adjust the second voltage signal.

[0236] The detection module 110 detects the circuit parameters in the following manner: Figures 1 to 10 Any embodiment described above will not be repeated here.

[0237] Depending on the load of the AC power grid, the current value of the first AC voltage signal and the current value of the second AC voltage signal may vary, thereby affecting the voltage value of the first AC voltage signal and the voltage value of the second AC voltage signal.

[0238] The first control signal may include a sinusoidal pulse width modulation signal, and the detection module 110 may detect the current value of the first AC voltage signal by connecting a detection resistor in series to the first AC voltage signal output terminal, etc. The control module 120 may adjust the first AC voltage signal by adjusting the duty cycle of the sinusoidal pulse width modulation signal.

[0239] The second control signal may include a sinusoidal pulse width modulation signal, and the detection module 110 may detect the current value of the second AC voltage signal by connecting a detection resistor in series to the second AC voltage signal output terminal, etc. The control module 120 may adjust the second AC voltage signal by adjusting the duty cycle of the sinusoidal pulse width modulation signal.

[0240] By adjusting the duty cycle of the sinusoidal pulse width modulation signal, the output energy of the first isolation transformer module 130 and the second isolation transformer module 160 can be adjusted to meet different load requirements.

[0241] The following provides multiple specific examples in combination with any of the above embodiments:

[0242] like Fig.17 As shown, this embodiment provides a flexible grid-connected inverter, which turns on the positive half-cycle enabling module in the positive half-cycle of the power grid, and controls the boost / buck circuit module 1 to output a 50HZ sinusoidal positive half-cycle; turns on the negative half-cycle enabling module in the negative half-cycle of the power grid, and controls the boost / buck circuit module 2 to output a 50HZ sinusoidal negative half-cycle; at the filter inductor position, that is, the LC filter module synthesizes a complete sinusoidal wave and then transmits it to the power grid; wherein after the MCU synchronizes the zero point, the constant current value of the 50HZ sinusoidal wave at each moment is set, and the constant current value of the sinusoidal wave at each moment is output and fed back at the secondary side of the high-frequency transformer.

[0243] like Fig.18 As shown, this embodiment provides a flexible grid-connected inverter, which consists of a buck-boost module 1 (i.e., a first isolation transformer module), a sinusoidal positive half-cycle enabling module (i.e., a first isolation switch module), an LC filter module (i.e., a first filter module and a second filter module), an MCU module (i.e., a control module), a current and zero-crossing detection module (i.e., a detection module), a buck-boost module 2 (i.e., a second isolation transformer module), and a sinusoidal negative half-cycle enabling module (i.e., a second filter module and a second filter module); wherein the current and zero-crossing detection module is used to feed back the grid zero-crossing signal and the current output by the inverter to the MCU module; wherein the buck-boost module 1 is used to feed back the grid zero-crossing signal and the current output by the inverter to the MCU module; The electric energy boost output of the solar panel is isolated in the positive half cycle of the sine wave, and the sine wave positive half cycle enabling module is used to control the electric energy output by the buck-boost module 1 to be transmitted to the grid during the positive half cycle of the grid and prevent the grid electric energy from being fed back to the secondary coil of the buck-boost module 1 during the negative half cycle of the grid; wherein, the LC filtering module is used to make the synthesized sinusoidal wave waveform smoother; wherein, the buck-boost module 2 is used to boost the electric energy output of the solar panel to isolate the negative half cycle of the sine wave; wherein, the sine wave negative half cycle enabling module is used to control the electric energy output by the buck-boost module 2 to be transmitted to the grid during the negative half cycle of the grid and prevent the grid electric energy from being fed back to the secondary coil of the buck-boost module 2 during the positive half cycle of the grid.

[0244] like Fig.19As shown, the flexible inverter program workflow includes: the MCU module first reads the grid zero-crossing signal through the current and zero-crossing detection module, reads the zero-crossing signal cycle to confirm that the grid is normally connected, and waits for the positive half-cycle zero-crossing. After the positive half-cycle zero-crossing arrives, the MCU module controls the positive half-cycle enabling module to be enabled, and calculates the sinusoidal current value I+ that needs to be output at the current moment in real time, and outputs PWM to control the buck-boost module 1 to output I+ current (according to the current read and the current fed back by the zero-crossing detection module, the PWM duty cycle is adjusted in real time). In this way, the current is calculated, the current is set, the current is read, and the PWM is adjusted to adjust the current until the positive half-cycle output of the sine wave is completed. The MCU module controls the positive half-cycle enabling module to be disabled, and then the MCU module waits for the negative half-cycle zero-crossing to arrive. After the negative half-cycle zero-crossing arrives, the MCU module controls the negative half-cycle enabling module to be enabled, and calculates the sinusoidal current value I- that needs to be output at the current moment in real time, and outputs PWM to control the buck-boost module 2 to output I- current (according to the current read and the current fed back by the zero-crossing detection module, the PWM duty cycle is adjusted in real time). In this way, the current is calculated, set, read and PWM is adjusted until the negative half cycle of the sine wave is output. The MCU module controls the negative half cycle enable module to be disabled; in this way, the output of a cycle of sine wave is completed.

[0245] like Figure 4 As shown, this embodiment provides a dual full-bridge flexible inverter circuit, wherein:

[0246] The sine wave positive half-cycle enabling module is composed of Q9, D9, T3, Q12, R1, C3, ZD1, R3, C5, and ZD3, among which Q9 is an enabling MOS, and D9, T3, and Q12 form a flyback isolation power supply to provide a driving signal for the Q9 control electrode, and R1, C3, ZD1, R3, C5, and ZD3 are protection devices for the MOS control electrode (to prevent the MOS tube driving electrode voltage from exceeding 20V).

[0247] The buck-boost module 1 is composed of T1, Q1, Q2, Q3, Q4, D1, D2, D3, and D4, wherein T1 is a DC / AC transformer, Q1, Q2, Q3, and Q4 form a full-bridge drive MOS to drive T1, and D1, D2, D3, and D4 form a bridge rectifier.

[0248] The LC filter module consists of L1, C2, and C3.

[0249] The sinusoidal wave negative half-cycle enabling module is composed of Q10, D10, T4, Q11, R2, C4, ZD2, R3, C5, and ZD3, among which Q10 is an enabling MOS, and D10, T4, and Q11 form a flyback isolation power supply to provide a driving signal for the Q10 control electrode, and R2, C4, ZD2, R3, C5, and ZD3 are protection devices for the MOS control electrode (to prevent the MOS tube driving electrode voltage from exceeding 20V).

[0250] The buck-boost module 2 is composed of T2, Q5, Q6, Q7, Q8, D5, D6, D7, and D8, wherein T2 is a DC / AC transformer, Q5, Q6, Q7, and Q8 form a full-bridge drive MOS to drive T2, and D5, D6, D7, and D8 form a bridge rectifier.

[0251] like Figure 5 As shown, this embodiment provides a dual output winding full-bridge flexible inverter circuit, wherein:

[0252] The T1 transformer has two output windings, the positive half cycle output T1 coil, the negative half cycle output T1-B coil, the rest of the circuit is the same as the attached Figure 4 The embodiments are similar and will not be described again here.

[0253] like Figure 8 As shown, this embodiment provides a dual flyback flexible inverter circuit power part, wherein:

[0254] T1 and T2 adopt flyback drive, and the rest of the circuit is the same as the attached Figure 4 The embodiments are similar and will not be described again. The circuit of the embodiment of the present disclosure is adopted.

[0255] A circuit and a control method according to any of the above embodiments:

[0256] First, two buck-boost circuits are used to directly synthesize a sine wave without the need for H-bridge chopping and polarity switching, which saves the hardware cost of the H-bridge inverter and avoids switching losses and electromagnetic radiation during H-bridge inversion.

[0257] Second, two-way buck-boost circuits are used to directly synthesize sine waves, without the need for high-power LCL sine wave filter components;

[0258] Third, this embodiment uses one-stage boosting, isolation, inversion, and grid connection, and only requires one-stage energy conversion, which reduces the energy conversion links and improves the conversion efficiency;

[0259] Fourth, this embodiment uses two buck-boost circuits to directly synthesize a sine wave, without the need for H-bridge chopping and polarity switching, and without the need for high-power LCL sine wave filtering components;

[0260] Fifth, this embodiment directly reads the current delivered to the grid by the inverter and controls the PWM of the buck-boost circuit, achieving sinusoidal wave generation and grid connection at the first level;

[0261] Fig. 20 : is a schematic diagram of the structure of the electronic device 9100 provided in the embodiment of the present disclosure. The electronic device 9100 may be a network device, or a terminal (such as a user device, etc.), or a chip, a chip system, or a processor, etc. that supports the network device to implement any of the above methods, or a chip, a chip system, or a processor, etc. that supports the terminal to implement any of the above information transmission methods. The electronic device 9100 may be used to implement the voltage conversion circuit control method described in the above method embodiment, and the details may refer to the description in the above method embodiment.

[0262] like Fig. 20 As shown, the electronic device 9100 includes one or more processors 9101. The processor 9101 can be a general-purpose processor or a dedicated processor, for example, a baseband processor or a central processing unit. The baseband processor can be used to process the communication protocol and communication data, and the central processing unit can be used to control the communication device (such as a base station, a baseband chip, a terminal device, a terminal device chip, a DU or a CU, etc.), execute a program, and process the data of the program. The processor 9101 is used to call instructions so that the electronic device 9100 executes any of the above voltage conversion circuit control methods.

[0263] In some embodiments, the electronic device 9100 further includes one or more memories 9102 for storing instructions. Optionally, all or part of the memory 9102 may also be outside the electronic device 9100.

[0264] In some embodiments, the electronic device 9100 further includes one or more transceivers 9103. When the electronic device 9100 includes one or more transceivers 9103, the steps of sending, receiving and / or acquiring in the above method are performed by the transceiver 9103, and the other steps are performed by the processor 9101.

[0265] In some embodiments, the steps of obtaining and the like in the above method may also be executed by the processor 9101 , for example, obtaining information from the memory 9102 .

[0266] In some embodiments, the transceiver may include a receiver and a transmitter, and the receiver and the transmitter may be separate or integrated. Optionally, the terms such as transceiver, transceiver unit, transceiver, transceiver circuit, etc. may be replaced with each other, the terms such as transmitter, transmission unit, transmitter, transmission circuit, etc. may be replaced with each other, and the terms such as receiver, receiving unit, receiver, receiving circuit, etc. may be replaced with each other.

[0267] Optionally, the electronic device 9100 further includes one or more interface circuits 9104, which are connected to the memory 9102. The interface circuit 9104 can be used to receive signals from the memory 9102 or other devices, and can be used to send signals to the memory 9102 or other devices. For example, the interface circuit 9104 can read instructions stored in the memory 9102 and send the instructions to the processor 9101.

[0268] The electronic device 9100 described in the above embodiments may be a network device or a terminal, but the scope of the electronic device 9100 described in the present disclosure is not limited thereto, and the structure of the electronic device 9100 may not be limited thereto. Fig. 20 The electronic device may be an independent device or may be part of a larger device. For example, the electronic device may be: (1) an independent integrated circuit IC, or a chip, or a chip system or subsystem; (2) a collection of one or more ICs, optionally, the above IC collection may also include a storage component for storing data and programs; (3) an ASIC, such as a modem; (4) a module that can be embedded in other devices; (5) a receiver, a terminal device, an intelligent terminal device, a cellular phone, a wireless device, a handheld device, a mobile unit, a vehicle-mounted device, a network device, a cloud device, an artificial intelligence device, etc.; (6) others, etc.

[0269] A person skilled in the art can understand that all or part of the steps of implementing the above method embodiment can be completed by hardware related to program commands, and the aforementioned program can be stored in a storage medium, and the storage medium includes: a mobile storage device, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and other media that can store program codes.

[0270] Alternatively, if the above-mentioned integrated unit of the present application is implemented in the form of a software function module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the embodiment of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several commands to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as mobile storage devices, ROM, RAM, magnetic disks or optical disks.

[0271] It should be understood that the above embodiments are exemplary and are not intended to include all possible implementations included in the claims. Various modifications and changes may be made on the basis of the above embodiments without departing from the scope of the present disclosure. Similarly, the various technical features of the above embodiments may be arbitrarily combined to form other embodiments of the utility model that may not be explicitly described. Therefore, the above embodiments only express several implementations of the utility model and do not limit the scope of protection of the utility model patent.

Claims

1. A voltage conversion circuit, characterized in that: The voltage conversion circuit comprises: A detection module, configured to detect a circuit parameter, wherein the circuit parameter includes at least one of the following: a first half cycle and a second half cycle of the alternating current, wherein the first half cycle is different from the second half cycle; A control module, used to control at least one of the first isolation transformer module, the first isolation switch module, the second isolation transformer module and the second isolation switch module according to the circuit parameters; The first isolation transformer module is configured to output a first voltage signal in the first half cycle according to an input DC voltage signal based on a first control signal of the control module; The first isolation switch module is used to conduct the first connection between the first isolation transformer module and the first filter module in the first half cycle based on the control of the control module, and to disconnect the first connection in the second half cycle; The first filtering module is used for, in the first half cycle, inputting a first voltage signal through the first connection, filtering the first voltage signal to obtain a first AC voltage signal, and outputting the first AC voltage signal to the AC power grid; The second isolation transformer module is configured to output a second voltage signal in the second half cycle according to the input DC voltage signal based on the second control signal of the control module; The second isolation switch module is used for switching on the second connection between the second isolation transformer module and the second filter module in the second half cycle based on the control of the control module, and switching off the second connection in the first half cycle; The second filtering module is used to input a second voltage signal through the second connection and filter the second voltage signal to obtain a second AC voltage signal in the second half cycle, and output the second AC voltage signal to the AC power grid.

2. The voltage conversion circuit according to claim 1, characterized in that: The first isolation transformer module comprises: a first full-bridge circuit, a first transformer and a first full-wave rectifier circuit; The first full-bridge circuit is used for converting the DC voltage signal into a first square wave voltage signal in the first half cycle based on the first sinusoidal pulse width modulation signal of the control module, and inputting the first square wave voltage signal into the first primary winding of the first transformer, wherein the first control signal includes the first sinusoidal pulse width modulation signal; The first full-wave rectifier circuit is used for full-wave rectifying the first induced voltage signal output by the first secondary winding of the first transformer inducing the first square wave voltage to obtain the first voltage signal; The second isolation transformer module comprises: a second full-bridge circuit, a second transformer and a second full-wave rectifier circuit; The second full-bridge circuit is used to convert the DC voltage signal into a second square wave voltage signal in the second half cycle based on the second sinusoidal pulse width modulation signal of the control module, and input the second square wave voltage signal to the second primary winding of the second transformer; the first control signal includes the second sinusoidal pulse width modulation signal; The second full-wave rectifier circuit is used to full-wave rectify the second induced voltage signal output by the second secondary winding of the second transformer inducing the second square wave voltage to obtain the second voltage signal.

3. The voltage conversion circuit according to claim 2, characterized in that: The first transformer and the second transformer are the same transformer, the first primary winding and the second primary winding are the same primary winding, the first full-bridge circuit and the second full-bridge circuit are the same full-bridge circuit; the first transformer includes the first secondary winding and the second secondary winding, The first full-bridge circuit is used to convert the DC voltage signal into a first square wave voltage signal in the first half cycle based on the first sinusoidal pulse width modulation signal, and input the first square wave voltage signal to the first primary winding; and to convert the DC voltage signal into a second square wave voltage signal in the second half cycle based on the second sinusoidal pulse width modulation signal, and input the second square wave voltage signal to the first primary winding; The first full-wave rectifier circuit is used for full-wave rectifying the first induced voltage signal output by the first secondary winding inducing the first square wave voltage to obtain the first voltage signal; The second full-wave rectifier circuit is used to full-wave rectify the second induced voltage signal output by the second secondary winding inducing the second square wave voltage to obtain the second voltage signal.

4. The voltage conversion circuit according to claim 1, characterized in that: The first isolation transformer module comprises: a first flyback isolation circuit consisting of a first switch tube, a third transformer and a first rectifier diode, wherein the first switch tube is connected to a first end of a third primary winding of the third transformer, a second end of the third primary winding inputs the DC voltage signal, and the first rectifier diode is connected to a third secondary winding of the third transformer; the first flyback isolation circuit converts the DC voltage signal into the first voltage signal in the first half cycle based on a third sinusoidal pulse width modulation signal input by the control module to the first switch tube; The second isolation transformer module comprises: a second flyback isolation circuit composed of a second switch tube, a fourth transformer and a second rectifier diode, wherein the second switch tube is connected to a first end of a fourth primary winding of the fourth transformer, the second end of the fourth primary winding inputs the DC voltage signal, the second rectifier diode is connected to a fourth secondary winding of the fourth transformer, and the second flyback isolation circuit converts the DC voltage signal into the second voltage signal in the second half cycle based on a fourth sinusoidal pulse width modulation signal input by the control module to the second switch tube; The first control signal includes the third sinusoidal pulse width modulation signal and the fourth sinusoidal pulse width modulation signal.

5. The voltage conversion circuit according to claim 1, characterized in that: The first isolation switch module comprises: a third flyback isolation circuit composed of a third switch tube, a fifth transformer and a third rectifier diode, and a fourth switch tube, wherein the third switch tube is connected to a first end of a fifth primary winding of the fifth transformer, a second end of the fifth primary winding inputs the DC voltage signal, the third rectifier diode is connected to a fifth secondary winding of the fifth transformer, and the third flyback isolation circuit outputs a first isolation switch signal to the fourth switch tube based on a first switch signal input by the control module to the third switch tube, so as to turn on or off the first connection; The second isolation switch module includes: a fourth flyback isolation circuit composed of a fifth switch tube, a sixth transformer and a fourth rectifier diode, and a sixth switch tube, wherein the fifth switch tube is connected to the first end of the sixth primary winding of the sixth transformer, the second end of the sixth primary winding is input with the DC voltage signal, the fourth rectifier diode is connected to the sixth secondary winding of the sixth transformer, and the fourth flyback isolation circuit outputs a second isolation switch signal to the sixth switch tube based on the second switch signal input by the control module to the fifth switch tube to turn on or off the second connection.

6. The voltage conversion circuit according to claim 5, characterized in that: The voltage conversion circuit further includes: a first voltage stabilization module, configured to perform voltage stabilization processing on the DC voltage signal input to the second end of the fifth primary winding and the second end of the sixth primary winding.

7. The voltage conversion circuit according to claim 5, characterized in that: The voltage conversion circuit further includes at least one of the following: a second voltage stabilization module and a third voltage stabilization module; The second voltage stabilizing module is connected between the third rectifier diode and the fourth switch tube, and is used for performing voltage stabilization processing on the first isolation switch signal; The third voltage stabilizing module is connected between the fourth rectifier diode and the sixth switch tube, and is used for performing voltage stabilizing processing on the second isolation switch signal.

8. The voltage conversion circuit according to claim 1, characterized in that: The first filtering module includes a first inductor-capacitor LC filtering circuit; The second filtering module includes a second inductor-capacitor (LC) filtering circuit.

9. The voltage conversion circuit according to claim 1, characterized in that: The first inductor of the first LC filter circuit and the second inductor of the second LC filter circuit are the same inductor.

10. A photovoltaic junction box, characterized in that: A voltage conversion circuit comprising any one of claims 1 to 9.

11. A photovoltaic module, characterized in that: It comprises the voltage conversion circuit according to any one of claims 1 to 9, or the photovoltaic junction box according to claim 10.

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