Conversion circuit and power conversion system

Abstract

The present invention discloses a conversion circuit and a power conversion system. The conversion circuit includes: a rectifier module, a control module, and a switch module. The rectifier module switches to an initial conduction state according to an initial state signal, so that the control module obtains the initial voltage of the load. The control module switches to a first control state according to the initial voltage and a first voltage threshold group, so as to generate a first control signal or a second control signal according to the voltage of the first rectifier end and the second rectifier end. The switch module controls the connection state between the rectifier module and the load according to the voltage of the first rectifier end, the voltage of the second rectifier end, and the actual voltage of the load, so as to control the connection state between the external AC power supply and the first receiving end of the load. The rectifier module is used to switch the conduction state according to the first control signal or the second control signal, so as to control the connection state between the external AC power supply and the second receiving end of the load. The conversion circuit of this embodiment can improve the conversion efficiency of the AC-DC converter.

Description

Technical Field

[0001] The present invention relates to the technical field of power converters, and in particular to a conversion circuit and a power conversion system. Background Art

[0002] Currently, a high-voltage linear regulator (LDO) needs to be provided in an AC-DC converter to reduce the voltage of high-voltage AC power and convert the AC power into DC power.

[0003] In the related art, since most of the voltage drop of the AC-DC converter is concentrated in the high-voltage linear regulator, the conversion efficiency of the AC-DC converter is low. Therefore, how to improve the conversion efficiency of the AC-DC converter has become a technical problem that needs to be solved urgently. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a conversion circuit that can reduce the system loss of an AC-DC converter, thereby improving the conversion efficiency of the AC-DC converter.

[0005] The present invention also provides a power conversion system having the above conversion circuit.

[0006] According to a first aspect of the present invention, a conversion circuit is applied to a device to be powered, wherein the device to be powered includes a load, and the load includes a first receiving end and a second receiving end; the conversion circuit includes:

[0007] a rectifier module, wherein a first rectifier terminal of the rectifier module is used to electrically connect to a first power supply terminal of an external AC power source, a second rectifier terminal of the rectifier module is used to electrically connect to a second power supply terminal of the external AC power source, and the rectifier module is further used to electrically connect to a second receiving terminal of the load;

[0008] A control module, the control module being electrically connected to the rectifier module and the load, respectively, and being configured to generate an initial state signal, a first control signal, and a second control signal; wherein the rectifier module is configured to switch to an initial conduction state according to the initial state signal, so that the control module obtains an initial voltage of the load; the control module is configured to switch to a first control state according to the initial voltage and a preset first voltage threshold group; the first control signal is a signal generated by the control module in the first control state according to the actual voltage of the load and the voltage at the first rectifier end; the second control signal is a signal generated by the control module in the first control state according to the actual voltage of the load and the voltage at the second rectifier end;

[0009] a switch module, the switch module being configured to be electrically connected to the first receiving end, the first rectifier end, and the second rectifier end of the load, respectively, and the switch module being configured to control a connection state between the rectifier module and the load based on a voltage at the first rectifier end, a voltage at the second rectifier end, and an actual voltage of the load, thereby controlling a connection state between the external AC power supply and the first receiving end of the load;

[0010] The rectifier module is configured to switch a conduction state according to the first control signal or the second control signal to control a connection state between the external AC power source and the second receiving end of the load.

[0011] The conversion circuit according to an embodiment of the present invention has at least the following advantageous effects: the control module generates an initial state signal, a first control signal, and a second control signal. The rectifier module switches to an initial conduction state based on the initial state signal, allowing the control module to obtain the initial voltage of the load. The control module switches to a first control state based on the initial voltage and a preset first voltage threshold group, generating a first control signal based on the actual voltage of the load and the voltage at the first rectifier terminal, and a second control signal based on the actual voltage of the load and the voltage at the second rectifier terminal. The switch module controls the connection state between the rectifier module and the load based on the voltage at the first rectifier terminal, the voltage at the second rectifier terminal, and the actual voltage of the load, thereby controlling the connection state between the external AC power supply and the first receiving terminal of the load. The rectifier module is configured to switch its conduction state based on the first control signal or the second control signal to control the connection state between the external AC power supply and the second receiving terminal of the load. The conversion circuit of this embodiment can achieve step-down conversion of the AC power supply signal without using a high-voltage linear regulator, thereby reducing system losses of the AC-DC converter and thereby improving the conversion efficiency of the AC-DC converter.

[0012] According to some embodiments of the present invention, the rectifier module includes:

[0013] a first rectifier unit, the first rectifier unit being configured to be electrically connected to the control module, the first power supply end, the second power supply end, the switch module, and the second receiving end of the load, respectively, and the first rectifier unit being configured to switch a conduction state according to the first control signal or the second control signal to control a connection state between the external AC power supply and the second receiving end of the load;

[0014] The second rectifier unit is used to be electrically connected to the second rectifier unit, the control module, the first power supply end, the second power supply end, the switch module, and the second receiving end of the load respectively, and the second rectifier unit is used to be shut down according to the second control signal.

[0015] According to some embodiments of the present invention, the first rectifying unit includes:

[0016] a first voltage-controlled flow element, wherein a gate of the first voltage-controlled flow element is electrically connected to the control module, a drain of the first voltage-controlled flow element is electrically connected to a first power supply terminal of the external AC power supply, a source of the first voltage-controlled flow element is electrically connected to a second receiving terminal of the load, the first voltage-controlled flow element is configured to be turned off according to the first control signal, and the first voltage-controlled flow element is configured to be turned on according to the second control signal;

[0017] A second voltage-controlled flow element, the gate of the second voltage-controlled flow element is used to be electrically connected to the control module, the drain of the second voltage-controlled flow element is used to be electrically connected to the second power supply end of the external AC power supply, the source of the second voltage-controlled flow element is used to be electrically connected to the second receiving end of the load, the second voltage-controlled flow element is used to be turned on according to the first control signal, and the second voltage-controlled flow element is used to be turned off according to the second control signal.

[0018] According to some embodiments of the present invention, the second rectifying unit includes:

[0019] a first capacitor, one end of the first capacitor being electrically connected to a first power supply end of the external AC power supply;

[0020] a third voltage-controlled flow element, wherein a gate of the third voltage-controlled flow element is electrically connected to the control module, a drain of the third voltage-controlled flow element is electrically connected to the other end of the first capacitor, a source of the third voltage-controlled flow element is electrically connected to the second receiving end of the load, and the third voltage-controlled flow element is configured to be shut down according to the first control signal or the second control signal;

[0021] a second capacitor, one end of the second capacitor being electrically connected to the second power supply end of the external AC power supply;

[0022] A fourth voltage-controlled flow element, wherein the gate of the fourth voltage-controlled flow element is used to be electrically connected to the control module, the drain of the fourth voltage-controlled flow element is used to be electrically connected to the other end of the second capacitor, the source of the fourth voltage-controlled flow element is used to be electrically connected to the second receiving end of the load, and the fourth voltage-controlled flow element is used to be shut down according to the first control signal or the second control signal.

[0023] According to some embodiments of the present invention, the control module is further configured to generate a third control signal and a fourth control signal; the control module is configured to switch to a second control state based on the actual voltage of the load and a preset second voltage threshold group; the third control signal is a signal generated by the control module in the second control state based on the actual voltage of the load and the voltage of the first rectifier end; the fourth control signal is a signal generated by the control module in the second control state based on the actual voltage of the load and the voltage of the second rectifier end;

[0024] The first pressure-controlled flow element is used to shut down according to the third control signal or the fourth control signal; the second pressure-controlled flow element is used to turn on according to the third control signal, and the second pressure-controlled flow element is used to shut down according to the fourth control signal; the third pressure-controlled flow element is used to shut down according to the third control signal, and the third pressure-controlled flow element is used to turn on according to the fourth control signal; the fourth pressure-controlled flow element is used to shut down according to the third control signal, and the fourth pressure-controlled flow element is used to turn on according to the fourth control signal.

[0025] According to some embodiments of the present invention, the control module is further configured to generate a fifth control signal and a sixth control signal; the control module is configured to switch to a third control state or a fourth control state according to the actual voltage of the load and a preset third voltage threshold group; the fifth control signal is a signal generated by the control module in the third control state, and the sixth control signal is a signal generated by the control module in the fourth control state;

[0026] The first pressure-controlled flow element is used to shut down according to the fifth control signal, and the first pressure-controlled flow element is used to turn on according to the sixth control signal; the second pressure-controlled flow element is used to shut down according to the fifth control signal, and the second pressure-controlled flow element is used to turn on according to the sixth control signal; the third pressure-controlled flow element is used to turn on according to the fifth control signal and the sixth control signal, respectively; the fourth pressure-controlled flow element is used to turn on according to the fifth control signal and the sixth control signal, respectively.

[0027] According to some embodiments of the present invention, the switch module includes:

[0028] a first diode, wherein an anode of the first diode is electrically connected to a first terminal of the external AC power source and a connection node of the rectifier module, and a cathode of the first diode is electrically connected to a first receiving terminal of the load;

[0029] A second diode, wherein the anode of the second diode is used to be electrically connected to the second end of the external AC power supply and the connection node of the rectifier module, and the cathode of the second diode is used to be electrically connected to the first receiving end of the load.

[0030] According to some embodiments of the present invention, the control module is further configured to generate a modulation signal, and the second rectifier unit further includes:

[0031] a third capacitor, one end of the third capacitor being electrically connected to a connection node between the third capacitor and the third voltage-controlled flow element;

[0032] a fifth voltage-controlled flow element, wherein the gate of the fifth voltage-controlled flow element is used to be electrically connected to the control module, the drain of the fifth voltage-controlled flow element is used to be electrically connected to the other end of the third capacitor, the source of the fifth voltage-controlled flow element is used to be electrically connected to the second receiving end of the load, and the fifth voltage-controlled flow element is used to be turned on or off according to the modulation signal;

[0033] a fourth capacitor, one end of the fourth capacitor being electrically connected to a connection node between the fourth capacitor and the fourth voltage-controlled flow element;

[0034] A sixth voltage-controlled flow element, wherein the gate of the sixth voltage-controlled flow element is used to be electrically connected to the control module, the drain of the sixth voltage-controlled flow element is used to be electrically connected to the other end of the fourth capacitor, the source of the sixth voltage-controlled flow element is used to be electrically connected to the second receiving end of the load, and the sixth voltage-controlled flow element is used to be turned on or off according to the modulation signal.

[0035] According to some embodiments of the present invention, the conversion circuit further includes:

[0036] A withstand voltage capacitor is used to be electrically connected to the first power supply end of the external AC power supply and the first rectifier end of the rectifier module respectively.

[0037] According to a second aspect of the present invention, a power conversion system includes:

[0038] Equipment to be powered;

[0039] The conversion circuit according to the first embodiment of the present invention.

[0040] The power conversion system according to the embodiment of the present invention has at least the following beneficial effects: by adopting the above-mentioned conversion circuit, the power conversion system realizes step-down conversion of the AC power supply signal without using a high-voltage linear regulator, thereby reducing the system loss of the AC-DC converter and further improving the conversion efficiency of the AC-DC converter.

[0041] Additional aspects and advantages of the present invention will be set forth in part in the description which follows and, in part, will be obvious from the description which follows, or may be learned by practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0043] Figure 1 A block diagram of a conversion circuit according to a specific embodiment of the present invention;

[0044] Figure 2 A circuit schematic diagram of a specific embodiment of the conversion circuit of the present invention;

[0045] Figure 3 FIG. 4 is a circuit schematic diagram of another specific embodiment of the conversion circuit of the present invention.

[0046] Reference numerals:

[0047] Rectifier module 100 , first rectifier unit 110 , second rectifier unit 120 , control module 200 , switch module 300 , external AC power supply 400 , load 500 . DETAILED DESCRIPTION

[0048] The following describes embodiments of the present invention in detail. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended only to explain the present invention and are not to be construed as limiting the present invention.

[0049] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0050] In the description of the present invention, "several" means more than one, "plurality" means more than two, "greater than," "less than," and "exceed" are understood to exclude the number itself, while "above," "below," and "within" are understood to include the number itself. The use of "first" and "second" in the description is solely for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, implicitly specifying the number of the indicated technical features, or implicitly specifying the order of the indicated technical features.

[0051] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0052] In the description of the present invention, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the exemplary expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0053] Currently, isolated AC-DC converter systems use a bulky transformer to convert the high-voltage AC grid voltage into low-voltage AC power. This is then rectified using a rectifier bridge consisting of four diodes to produce low-voltage DC power for powering the device being powered. Non-isolated converters primarily use high-voltage linear regulators for voltage reduction. These use off-chip diodes to form a rectifier bridge, directly converting the high-voltage AC grid voltage into high-voltage DC power. A high-voltage linear regulator then reduces this high-voltage DC power to the low-voltage DC power required to power the device. This high-voltage linear regulator typically consists of a high-voltage field-effect transistor (FET) and some control circuitry.

[0054] In the related art, since most of the voltage drop of the AC-DC converter is concentrated in the high-voltage linear regulator, the conversion efficiency of the AC-DC converter is low. Therefore, how to improve the conversion efficiency of the AC-DC converter has become a technical problem that needs to be solved urgently.

[0055] Based on this, the embodiments of the present disclosure provide a conversion circuit and a power conversion system, which can reduce the system loss of the AC-DC converter, thereby improving the conversion efficiency of the AC-DC converter.

[0056] like Figure 1As shown, an embodiment of the present invention provides a conversion circuit, which includes: a rectifier module 100, a control module 200, and a switch module 300. The conversion circuit is applied to a device to be powered, including a load 500, and the load 500 includes a first receiving end and a second receiving end. The first rectifier end of the rectifier module 100 is used to electrically connect to the first power supply end of the external AC power supply 400, and the second rectifier end of the rectifier module 100 is used to electrically connect to the second power supply end of the external AC power supply 400. The rectifier module 100 is also used to electrically connect to the second receiving end of the load 500; the control module 200 is used to electrically connect to the rectifier module 100 and the load 500, respectively, and the control module 200 is used to generate an initial state signal, a first control signal, and a second control signal; wherein, the rectifier module 100 is used to switch to an initial conduction state according to the initial state signal, so that the control module 200 obtains the initial voltage of the load 500; the control module 200 is used to switch to a first control state according to the initial voltage and a preset first voltage threshold group; the first control signal is the control module 200 in the first control state, based on The control module 200 is configured to generate a signal according to the actual voltage of the load 500 and the voltage of the first rectifier end; the second control signal is a signal generated by the control module 200 in the first control state according to the actual voltage of the load 500 and the voltage of the second rectifier end; the switch module 300 is used to be electrically connected to the first receiving end, the first rectifier end, and the second rectifier end of the load 500, respectively. The switch module 300 is used to control the connection state of the rectifier module 100 and the load 500 according to the voltage of the first rectifier end, the voltage of the second rectifier end, and the actual voltage of the load 500, so as to control the connection state of the external AC power supply 400 and the first receiving end of the load 500; wherein, the rectifier module 100 is used to switch the conduction state according to the first control signal or the second control signal to control the connection state of the external AC power supply 400 and the second receiving end of the load 500.

[0057] Specifically, the external AC power supply 400 is AC mains electricity with a voltage range of 85V-264V. The load 500 includes a device to be powered, which operates using a DC signal. The first power supply terminal of the external AC power supply 400 is electrically connected to the first rectifier terminal of the rectifier module 100, and the second power supply terminal of the external AC power supply 400 is electrically connected to the second rectifier terminal of the rectifier module 100. The first receiving terminal of the load 500 is electrically connected to the switch module 300, and the second receiving terminal of the load 500 is electrically connected to the rectifier module 100. The switch module 300 is also electrically connected to the first rectifier terminal and the second rectifier terminal of the rectifier module 100, respectively. The control module 200 is electrically connected to the rectifier module 100 and the load 500, respectively.

[0058] When the device to be powered is started, the control module 200 generates an initial state signal, which is received by the rectifier module 100. The rectifier module 100 switches to the initial conduction state according to the initial state signal. In the initial conduction state, the rectifier module 100 can rectify the AC signal provided by the external AC power source 400, causing the switch module 300 to open the power supply channel between the external AC power source 400 and the first receiving end of the load 500. At this time, an initial voltage is generated at both ends of the load 500. The control module 200 obtains the initial voltage of the load 500, compares the initial voltage with a preset first voltage threshold group, and switches its own control state based on the comparison result. For example, the first voltage threshold group includes a reference threshold A1. If the initial voltage Vo1 generated by the load 500 is less than A1, it indicates that the load 500 has a low ability to consume the supply current. At this time, the control module 200 switches to the first control state. In the first control state, the control module 200 obtains the actual voltage of the load 500, the voltage at the first rectifier terminal of the rectifier module 100, and the voltage at the second rectifier terminal of the rectifier module 100, and generates a first control signal based on the voltage at the first rectifier terminal and the actual voltage of the load 500, and generates a second control signal based on the voltage at the second rectifier terminal and the actual voltage of the load 500. The actual voltage of the load 500 is the real-time voltage of the load 500 after the control module 200 determines the working state.

[0059] When the voltage at the first rectifier terminal of the rectifier module 100 gradually increases with the AC signal, and the voltage at the first rectifier terminal is greater than the actual voltage of the load 500, the switch module 300 opens the signal path between the first receiving terminal of the load 500 and the first rectifier terminal of the rectifier module 100, thereby opening the power supply path between the first receiving terminal of the load 500 and the external AC power source 400. At this point, the control module 200 generates a first control signal, and the rectifier module 100 opens the power supply path between the second receiving terminal of the load 500 and the external AC power source 400 in accordance with the first control signal, thereby achieving a voltage reduction operation on the AC signal provided by the external AC power source 400 and simultaneously converting the AC signal into a DC signal, allowing the load 500 to operate according to the DC signal.

[0060] When the voltage at the first rectifier terminal of the rectifier module 100 gradually decreases with the AC signal and becomes less than the actual voltage of the load 500, the switch module 300 disconnects the signal path between the first receiving terminal of the load 500 and the first rectifier terminal of the rectifier module 100, thereby disconnecting the power supply path between the first receiving terminal of the load 500 and the external AC power source 400. At this point, the control module 200 generates a first control signal, and the rectifier module 100 disconnects the power supply path between the second receiving terminal of the load 500 and the external AC power source 400 in accordance with the first control signal. The load 500 then operates with power supplied by the output capacitor. The output capacitor and the load 500 are connected in parallel.

[0061] When the voltage at the second rectifier terminal of the rectifier module 100 gradually increases with the AC signal, and the voltage at the second rectifier terminal is greater than the actual voltage of the load 500, the switch module 300 opens the signal path between the first receiving terminal of the load 500 and the second rectifier terminal of the rectifier module 100, thereby opening the power supply path between the first receiving terminal of the load 500 and the external AC power source 400. At this point, the control module 200 generates a second control signal, and the rectifier module 100 opens the power supply path between the second receiving terminal of the load 500 and the external AC power source 400 in accordance with the second control signal, thereby achieving a voltage reduction operation on the AC signal provided by the external AC power source 400 and simultaneously converting the AC signal into a DC signal, allowing the load 500 to operate according to the DC signal.

[0062] When the voltage at the second rectifier terminal of the rectifier module 100 gradually decreases with the AC signal and becomes lower than the actual voltage of the load 500, the switch module 300 disconnects the signal path between the first receiving terminal of the load 500 and the second rectifier terminal of the rectifier module 100, thereby disconnecting the power path between the first receiving terminal of the load 500 and the external AC power source 400. At this point, the control module 200 generates a second control signal, and the rectifier module 100 disconnects the power path between the second receiving terminal of the load 500 and the external AC power source 400 in accordance with the second control signal. The load 500 then operates with power supplied by the output capacitor.

[0063] Through the above control process, while achieving the voltage reduction and signal conversion of the AC signal, when the ability of the conversion circuit to provide the DC signal current is greater than the current consumption ability of the load 500, the conversion circuit can increase the voltage of the DC signal received by the load 500.

[0064] According to the conversion circuit of the embodiment of the present invention, the control module 200 generates an initial state signal, a first control signal, and a second control signal. The rectifier module 100 switches to an initial conduction state based on the initial state signal, allowing the control module 200 to obtain an initial voltage of the load 500. Based on the initial voltage and a preset first voltage threshold set, the control module 200 switches to a first control state, generating a first control signal based on the actual voltage of the load 500 and the voltage at the first rectifier terminal, and a second control signal based on the actual voltage of the load 500 and the voltage at the second rectifier terminal. The switch module 300 controls the connection between the rectifier module 100 and the load 500 based on the voltage at the first rectifier terminal, the voltage at the second rectifier terminal, and the actual voltage of the load 500, thereby controlling the connection between the external AC power source 400 and the first receiving terminal of the load 500. The rectifier module 100 switches to a conduction state based on the first control signal or the second control signal, thereby controlling the connection between the external AC power source 400 and the second receiving terminal of the load 500. The conversion circuit of this embodiment can achieve voltage reduction conversion of the AC power supply signal without using a high-voltage linear regulator, thereby reducing the system loss of the AC-DC converter and further improving the conversion efficiency of the AC-DC converter.

[0065] like Figure 2 As shown, in some specific embodiments of the present invention, the rectifier module 100 includes: a first rectifier unit and a second rectifier unit. The first rectifier unit is used to be electrically connected to the control module 200, the first power supply end, the second power supply end, the switch module 300, and the second receiving end of the load 500, respectively. The first rectifier unit is used to switch the conductive state according to the first control signal or the second control signal to control the connection state between the external AC power supply 400 and the second receiving end of the load 500; the second rectifier unit is used to be electrically connected to the second rectifier unit, the control module 200, the first power supply end, the second power supply end, the switch module 300, and the second receiving end of the load 500, respectively. The second rectifier unit is used to be shut down according to the second control signal.

[0066] Specifically, the first rectifier unit and the second rectifier unit are connected in parallel. One parallel node between the first rectifier unit and the second rectifier unit is a first rectifier end, and the other parallel node between the first rectifier unit and the second rectifier unit is a second rectifier end. The first rectifier end is electrically connected to the first power supply end of the external AC power supply 400 and the switch module 300, respectively. The second rectifier end is electrically connected to the second power supply end of the external AC power supply 400 and the switch module 300, respectively. The first rectifier unit and the second rectifier unit are each electrically connected to the second receiving end of the load 500.

[0067] When the voltage at the first rectifier terminal gradually increases with the AC signal and becomes greater than the actual voltage of the load 500, the switch module 300 opens the power supply path between the first receiving terminal of the load 500 and the external AC power source 400, and the control module 200 generates a first control signal. Based on the first control signal, the first rectifier unit opens the power supply path between the second receiving terminal of the load 500 and the external AC power source 400, and the second rectifier unit shuts down based on the first control signal. This achieves a voltage reduction operation on the AC signal provided by the external AC power source 400 and also converts the AC signal into a DC signal, allowing the load 500 to operate based on the DC signal.

[0068] When the voltage at the first rectifier terminal gradually decreases with the AC signal and becomes less than the actual voltage of the load 500, the switch module 300 disconnects the power supply path between the first receiving terminal of the load 500 and the external AC power source 400, and the control module 200 generates a first control signal. Based on the first control signal, the first rectifier unit disconnects the power supply path between the second receiving terminal of the load 500 and the external AC power source 400, and the second rectifier unit shuts down based on the first control signal. At this point, the load 500 operates with power supplied by the output capacitor CL.

[0069] When the voltage at the second rectifier terminal gradually increases with the AC signal and becomes greater than the actual voltage of the load 500, the switch module 300 opens the power supply path between the first receiving terminal of the load 500 and the external AC power source 400, and the control module 200 generates a second control signal. Based on the second control signal, the first rectifier unit opens the power supply path between the second receiving terminal of the load 500 and the external AC power source 400, and the second rectifier unit shuts down based on the second control signal. This achieves a voltage reduction operation for the AC signal provided by the external AC power source 400, while also converting the AC signal into a DC signal, allowing the load 500 to operate based on the DC signal.

[0070] When the voltage at the second rectifier terminal gradually decreases with the AC signal and becomes less than the actual voltage of the load 500, the switch module 300 disconnects the power supply path between the first receiving terminal of the load 500 and the external AC power source 400, and the control module 200 generates a second control signal. Based on the second control signal, the first rectifier unit disconnects the power supply path between the second receiving terminal of the load 500 and the external AC power source 400, and the second rectifier unit shuts down based on the second control signal. The load 500 then operates with power supplied by the output capacitor CL.

[0071] like Figure 2As shown, in some specific embodiments of the present invention, the first rectifier unit includes: a first voltage-controlled flow element M1 and a second voltage-controlled flow element M2. The gate of the first voltage-controlled flow element M1 is used to be electrically connected to the control module 200, the drain of the first voltage-controlled flow element M1 is used to be electrically connected to the first power supply terminal of the external AC power supply 400, the source of the first voltage-controlled flow element M1 is used to be electrically connected to the second receiving terminal of the load 500, the first voltage-controlled flow element M1 is used to be turned off according to the first control signal, and the first voltage-controlled flow element M1 is used to be turned on according to the second control signal; the gate of the second voltage-controlled flow element M2 is used to be electrically connected to the control module 200, the drain of the second voltage-controlled flow element M2 is used to be electrically connected to the second power supply terminal of the external AC power supply 400, the source of the second voltage-controlled flow element M2 is used to be electrically connected to the second receiving terminal of the load 500, the second voltage-controlled flow element M2 is used to be turned on according to the first control signal, and the second voltage-controlled flow element M2 is used to be turned off according to the second control signal.

[0072] Specifically, the control module 200 is electrically connected to the gate of the first voltage-controlled flow element M1 and the gate of the second voltage-controlled flow element M2, respectively. The drain of the first voltage-controlled flow element M1 is electrically connected to the first power supply terminal of the external AC power supply 400, and the drain of the second voltage-controlled flow element M2 is electrically connected to the second power supply terminal of the external AC power supply 400. The source of the first voltage-controlled flow element M1 and the source of the second voltage-controlled flow element M2 are both electrically connected to the second receiving terminal of the load 500, and the second receiving terminal of the load 500 is grounded. The connection node between the drain of the first voltage-controlled flow element M1 and the first power supply terminal of the external AC power supply 400 is the first rectifier terminal, and the connection node between the drain of the second voltage-controlled flow element M2 and the second power supply terminal of the external AC power supply 400 is the second rectifier terminal.

[0073] When the voltage at the first rectifier end gradually increases with the AC signal, and the voltage at the first rectifier end is greater than the actual voltage of the load 500, the switch module 300 opens the power supply channel between the first receiving end of the load 500 and the external AC power supply 400, and the control module 200 generates a first control signal. The first voltage-controlled flow element M1 is turned off according to the first control signal, the second voltage-controlled flow element M2 is turned on according to the first control signal, and the second rectifier unit is turned off according to the first control signal. At this time, the external AC power supply 400 can form a DC current loop through the second voltage-controlled flow element M2, the switch module 300, and the load 500, thereby realizing the step-down operation of the AC signal provided by the external AC power supply 400, and at the same time converting the AC signal into a DC signal, so that the load 500 works according to the DC signal.

[0074] When the voltage at the first rectifier terminal gradually decreases with the AC signal and becomes less than the actual voltage of the load 500, the switch module 300 disconnects the power supply path between the first receiving terminal of the load 500 and the external AC power source 400, and the control module 200 generates a first control signal. The first voltage-controlled current element M1, the second voltage-controlled current element M2, and the second rectifier unit are all turned off in response to the first control signal. The external AC power source 400 is unable to form a DC current loop with the load 500, and the load 500 now operates with power supplied by the output capacitor CL.

[0075] When the voltage at the second rectifier end gradually increases with the AC signal, and the voltage at the second rectifier end is greater than the actual voltage of the load 500, the switch module 300 opens the power supply channel between the first receiving end of the load 500 and the external AC power supply 400, and the control module 200 generates a second control signal. The first voltage-controlled flow element M1 is turned on according to the second control signal, the second voltage-controlled flow element M2 is turned off according to the second control signal, and the second rectifier unit is turned off according to the second control signal. At this time, the external AC power supply 400 can form a DC current loop through the first voltage-controlled flow element M1, the switch module 300, and the load 500, thereby realizing the step-down operation of the AC signal provided by the external AC power supply 400, and at the same time converting the AC signal into a DC signal, so that the load 500 works according to the DC signal.

[0076] When the voltage at the second rectifier terminal gradually decreases with the AC signal and becomes less than the actual voltage of the load 500, the switch module 300 disconnects the power supply path between the first receiving terminal of the load 500 and the external AC power source 400, and the control module 200 generates a second control signal. The first voltage-controlled current element M1, the second voltage-controlled current element M2, and the second rectifier unit are all turned off in response to the second control signal. The external AC power source 400 is unable to form a DC current loop with the load 500, and the load 500 now operates with power supplied by the output capacitor CL.

[0077] like Figure 2As shown, in some specific embodiments of the present invention, the second rectifier unit includes: a first capacitor Cp1, a third voltage-controlled flow element M3, a second capacitor Cp2, and a fourth voltage-controlled flow element M4. One end of the first capacitor Cp1 is used to be electrically connected to the first power supply end of the external AC power supply 400; the gate of the third voltage-controlled flow element M3 is used to be electrically connected to the control module 200, the drain of the third voltage-controlled flow element M3 is used to be electrically connected to the other end of the first capacitor Cp1, the source of the third voltage-controlled flow element M3 is used to be electrically connected to the second receiving end of the load 500, and the third voltage-controlled flow element M3 is used to be shut down according to the first control signal or the second control signal; one end of the second capacitor Cp2 is used to be electrically connected to the second power supply end of the external AC power supply 400; the gate of the fourth voltage-controlled flow element M4 is used to be electrically connected to the control module 200, the drain of the fourth voltage-controlled flow element M4 is used to be electrically connected to the other end of the second capacitor Cp2, the source of the fourth voltage-controlled flow element M4 is used to be electrically connected to the second receiving end of the load 500, and the fourth voltage-controlled flow element M4 is used to be shut down according to the first control signal or the second control signal.

[0078] Specifically, the control module 200 is electrically connected to the gate of the third voltage-controlled flow element M3 and the gate of the fourth voltage-controlled flow element M4, respectively. One end of the first capacitor Cp1 is electrically connected to the first power supply terminal of the external AC power supply 400, the drain of the third voltage-controlled flow element M3 is electrically connected to the other end of the first capacitor Cp1, one end of the second capacitor Cp2 is electrically connected to the second power supply terminal of the external AC power supply 400, and the drain of the fourth voltage-controlled flow element M4 is electrically connected to the other end of the second capacitor Cp2. The source of the third voltage-controlled flow element M3 and the source of the fourth voltage-controlled flow element M4 are both electrically connected to the second receiving end of the load 500, and the second receiving end of the load 500 is grounded. The connection node between the first capacitor Cp1 and the first power supply terminal of the external AC power supply 400 is the first rectifier terminal, and the connection node between the second capacitor Cp2 and the second power supply terminal of the external AC power supply 400 is the second rectifier terminal. Among them, the first capacitor Cp1 and the second capacitor Cp2 are both used to conduct according to the AC signal.

[0079] When the voltage at the first rectifier terminal gradually increases with the AC signal and the voltage at the first rectifier terminal is greater than the actual voltage of the load 500, the control module 200 generates a first control signal, at which point the third and fourth voltage-controlled flow elements M3 and M4 are both turned off according to the first control signal. When the voltage at the first rectifier terminal gradually decreases with the AC signal and the voltage at the first rectifier terminal is less than the actual voltage of the load 500, the control module 200 generates a first control signal, at which point the third and fourth voltage-controlled flow elements M3 and M4 are both turned off according to the first control signal.

[0080] When the voltage at the second rectifier terminal gradually increases with the AC signal and the voltage at the second rectifier terminal is greater than the actual voltage of the load 500, the control module 200 generates a second control signal, and the third and fourth voltage-controlled flow elements M3 and M4 are both turned off according to the second control signal. When the voltage at the second rectifier terminal gradually decreases with the AC signal and the voltage at the second rectifier terminal is less than the actual voltage of the load 500, the control module 200 generates a second control signal, and the third and fourth voltage-controlled flow elements M3 and M4 are both turned off according to the second control signal.

[0081] like Figure 2 As shown, in some specific embodiments of the present invention, the control module 200 is also used to generate a third control signal and a fourth control signal; the control module 200 is used to switch to the second control state according to the actual voltage of the load 500 and the preset second voltage threshold group; the third control signal is a signal generated by the control module 200 in the second control state according to the actual voltage of the load 500 and the voltage of the first rectifier end; the fourth control signal is a signal generated by the control module 200 in the second control state according to the actual voltage of the load 500 and the voltage of the second rectifier end; the first voltage-controlled flow element M1 is used to turn off according to the third control signal or the fourth control signal; the second voltage-controlled flow element M2 is used to turn on according to the third control signal, and the second voltage-controlled flow element M2 is used to turn off according to the fourth control signal; the third voltage-controlled flow element M3 is used to turn off according to the third control signal, and the third voltage-controlled flow element M3 is used to turn on according to the fourth control signal; the fourth voltage-controlled flow element M4 is used to turn off according to the third control signal, and the fourth voltage-controlled flow element M4 is used to turn on according to the fourth control signal.

[0082] Specifically, after the control module 200 switches to the first control state, the conversion circuit can gradually increase the voltage of the DC signal received by the load 500. The control module 200 compares the actual voltage of the load 500 with a preset second voltage threshold set in real time and switches the control state of the control module 200 based on the comparison result. For example, the second voltage threshold set includes two reference thresholds A1 and A2, where A2>A1. If the actual voltage Vo2 of the load 500 is still less than A1, the control module 200 does not switch the control state. If the actual voltage Vo2 of the load 500 is greater than A1 but less than A2, the control module 200 switches to the second control state. In the second control state, the control module 200 obtains the actual voltage of the load 500, the voltage at the first rectifier terminal of the rectifier module 100, and the voltage at the second rectifier terminal of the rectifier module 100. It generates a third control signal based on the voltage at the first rectifier terminal and the actual voltage of the load 500, and generates a fourth control signal based on the voltage at the second rectifier terminal and the actual voltage of the load 500.

[0083] In the second control state, when the voltage at the first rectifier end gradually increases with the AC signal, and the voltage at the first rectifier end is greater than the actual voltage of the load 500, the switch module 300 opens the power supply channel between the first receiving end of the load 500 and the external AC power supply 400, and the control module 200 generates a third control signal. The first voltage-controlled flow element M1 is turned off according to the third control signal, the second voltage-controlled flow element M2 is turned on according to the third control signal, and the third voltage-controlled flow element M3 and the fourth voltage-controlled flow element M4 are turned off according to the third control signal. At this time, the external AC power supply 400 can form a DC current loop through the second voltage-controlled flow element M2, the switch module 300, and the load 500, thereby realizing the step-down operation of the AC signal provided by the external AC power supply 400, and at the same time converting the AC signal into a DC signal, so that the load 500 works according to the DC signal.

[0084] When the voltage at the first rectifier terminal gradually decreases with the AC signal and becomes less than the actual voltage of the load 500, the switch module 300 disconnects the power supply path between the first receiving terminal of the load 500 and the external AC power source 400, and the control module 200 generates a third control signal. The first, second, third, and fourth voltage-controlled flow elements M1, M2, M3, and M4 are all turned off in response to the third control signal. The external AC power source 400 is unable to form a DC current loop with the load 500, and the load 500 now operates with power supplied by the output capacitor CL.

[0085] In the second control state, when the voltage at the second rectifier terminal gradually increases and decreases with the AC signal, the control module 200 generates a fourth control signal. The first and second voltage-controlled flow elements M1 and M2 are both turned off according to the fourth control signal, and the third and fourth voltage-controlled flow elements M3 and M4 are turned on according to the fourth control signal. At this time, the external AC power supply 400 can only form a current loop with the third and fourth voltage-controlled flow elements M3 and M4, respectively, and the ground terminal. That is, at this time, the external AC power supply 400 will not power the load 500 through the rectifier module 100.

[0086] Through the above control process, while achieving voltage reduction and signal conversion for the AC signal, the conversion circuit can also reduce the voltage of the DC signal received by load 500 when the current capacity of the conversion circuit to provide the DC signal is less than the current consumption capacity of load 500. Thereafter, control module 200 again determines the actual voltage of load 500. Referring to the above example, if the actual voltage Vo2 of load 500 is now less than A1, control module 200 switches back to the first control state.

[0087] like Figure 2As shown, in some specific embodiments of the present invention, the control module 200 is also used to generate a fifth control signal and a sixth control signal; the control module 200 is used to switch to a third control state or a fourth control state according to the actual voltage of the load 500 and a preset third voltage threshold group; the fifth control signal is a signal generated by the control module 200 in the third control state, and the sixth control signal is a signal generated by the control module 200 in the fourth control state; the first pressure-controlled flow element M1 is used to shut down according to the fifth control signal, and the first pressure-controlled flow element M1 is used to turn on according to the sixth control signal; the second pressure-controlled flow element M2 is used to shut down according to the fifth control signal, and the second pressure-controlled flow element M2 is used to turn on according to the sixth control signal; the third pressure-controlled flow element M3 is used to turn on according to the fifth control signal and the sixth control signal, respectively; the fourth pressure-controlled flow element M4 is used to turn on according to the fifth control signal and the sixth control signal, respectively.

[0088] Specifically, the control module 200 compares the actual voltage of the load 500 with the preset third and fourth voltage threshold groups in real time and switches the control state of the control module 200 based on the comparison results. For example, the third voltage threshold group includes three reference thresholds A1, A2, and A3, where A3>A2>A1. When the actual voltage Vo2 of the load 500 is greater than A2, it indicates that the converter circuit's ability to provide DC signal current cannot meet the current consumption capacity of the load 500. In this case, if the actual voltage Vo2 of the load 500 is greater than A2 and less than A3, the control module 200 switches to the third control state; if the actual voltage Vo2 of the load 500 is greater than A3, the control module 200 switches to the fourth control state.

[0089] In the third control state, the control module 200 generates a fifth control signal. The first and second voltage-controlled flow elements M1, M2 are both turned off according to the fifth control signal, while the third and fourth voltage-controlled flow elements M3, M4 are turned on according to the fourth control signal. At this point, the external AC power source 400 can only form a current loop with the third and fourth voltage-controlled flow elements M3, M4, and ground. In other words, the external AC power source 400 does not power the load 500 via the rectifier module 100.

[0090] In the fourth control state, the control module 200 generates a sixth control signal. The first, second, third, and fourth voltage-controlled flow elements M1, M2, M3, and M4 are all turned on according to the sixth control signal. At this time, the external AC power supply 400 forms a current loop through the first, second, third, and fourth voltage-controlled flow elements M1, M2, M3, and M4, and the ground terminal. In other words, the external AC power supply 400 does not supply power to the load 500 through the rectifier module 100.

[0091] Through the above control process, while achieving the voltage reduction and signal conversion of the AC signal, since the current capability of the conversion circuit to provide the DC signal is 0, the conversion circuit can reduce the voltage of the DC signal received by the load 500.

[0092] like Figure 2 As shown, in some specific embodiments of the present invention, the switch module 300 includes: a first diode D1 and a second diode D2. The anode of the first diode D1 is used to electrically connect to the first terminal of the external AC power source 400 and the connection node of the rectifier module 100, and the cathode of the first diode D1 is used to electrically connect to the first receiving terminal of the load 500; the anode of the second diode D2 is used to electrically connect to the second terminal of the external AC power source 400 and the connection node of the rectifier module 100, and the cathode of the second diode D2 is used to electrically connect to the first receiving terminal of the load 500.

[0093] Specifically, the first receiving terminal of the load 500 is electrically connected to the cathode of the first diode D1 and the cathode of the second diode D2, respectively. The anode of the first diode D1 is electrically connected to the first rectifier terminal, and the anode of the second diode D2 is electrically connected to the second rectifier terminal. When the voltage at the first rectifier terminal is greater than the actual voltage of the load 500, the first diode D1 is turned on; when the voltage at the first rectifier terminal is less than the actual voltage of the load 500, the first diode D1 is turned off. When the voltage at the second rectifier terminal is greater than the actual voltage of the load 500, the second diode D2 is turned on; when the voltage at the second rectifier terminal is less than the actual voltage of the load 500, the second diode D2 is turned off.

[0094] like Figure 3 As shown, in some specific embodiments of the present invention, the control module 200 is further used to generate a modulation signal, and the second rectifier unit further includes: a third capacitor Cp3, a fifth voltage-controlled flow element M5, a fourth capacitor Cp4, and a sixth voltage-controlled flow element M6. One end of the third capacitor Cp3 is used to be electrically connected to the connection node between the third capacitor Cp3 and the third voltage-controlled flow element M3; the gate of the fifth voltage-controlled flow element M5 is used to be electrically connected to the control module 200, the drain of the fifth voltage-controlled flow element M5 is used to be electrically connected to the other end of the third capacitor Cp3, the source of the fifth voltage-controlled flow element M5 is used to be electrically connected to the second receiving end of the load 500, and the fifth voltage-controlled flow element M5 is used to be turned on or off according to the modulation signal; one end of the fourth capacitor Cp4 is used to be electrically connected to the connection node between the fourth capacitor Cp4 and the fourth voltage-controlled flow element M4; the gate of the sixth voltage-controlled flow element M6 is used to be electrically connected to the control module 200, the drain of the sixth voltage-controlled flow element M6 is used to be electrically connected to the other end of the fourth capacitor Cp4, the source of the sixth voltage-controlled flow element M6 is used to be electrically connected to the second receiving end of the load 500, and the sixth voltage-controlled flow element M6 is used to be turned on or off according to the modulation signal.

[0095] Specifically, the control module 200 is electrically connected to the gate of the fifth voltage-controlled flow element M5 and the gate of the sixth voltage-controlled flow element M6, respectively. One end of the third capacitor Cp3 is electrically connected to the connection node between the first capacitor Cp1 and the third voltage-controlled flow element M3, and the drain of the fifth voltage-controlled flow element M5 is electrically connected to the other end of the third capacitor Cp3. One end of the fourth capacitor Cp4 is electrically connected to the connection node between the second capacitor Cp2 and the fourth voltage-controlled flow element M4, and the drain of the sixth voltage-controlled flow element M6 is electrically connected to the other end of the fourth capacitor Cp4. The source of the fifth voltage-controlled flow element M5 and the source of the sixth voltage-controlled flow element M6 are both electrically connected to the second receiving end of the load 500. Among them, the third capacitor Cp3 and the fourth capacitor Cp4 are both used to conduct according to the AC signal.

[0096] The control module 200 generates a modulation signal, and the fifth voltage-controlled flow element M5 and the sixth voltage-controlled flow element M6 are turned on or off according to the modulation signal, thereby controlling the voltage at the first rectifier end and the voltage at the second rectifier end, thereby reducing the static power consumption of the conversion circuit.

[0097] like Figure 2 、 Figure 3 As shown, in some specific embodiments of the present invention, the conversion circuit further includes a withstand voltage capacitor CX. The withstand voltage capacitor CX is used to be electrically connected to the first power supply terminal of the external AC power supply 400 and the first rectifier terminal of the rectifier module 100 respectively.

[0098] Specifically, the withstand voltage capacitor CX is connected in series with the first power supply terminal of the external AC power source 400 and the first rectifier terminal of the rectifier module 100. Since the withstand voltage capacitor CX is electrically connected to the first power supply terminal of the external AC power source 400, the withstand voltage capacitor CX can reduce the input voltage of the AC signal provided by the external AC power source 400. It will be understood that the capacitance of the withstand voltage capacitor CX can be adaptively adjusted according to the power supply conditions of the external AC power source 400.

[0099] The following describes in detail how to obtain the electrical parameters of each component in the conversion circuit provided in the embodiment of the present application.

[0100] In a specific embodiment of the present invention, referring to Figure 2 、 Figure 3 The first voltage control flow element M1, the second voltage control flow element M2, the third voltage control flow element M3, the fourth voltage control flow element M4, the fifth voltage control flow element M5, and the sixth voltage control flow element M6 are all selected as field effect transistors. The AC signal provided by the external AC power supply 400 is V LINE , the voltage between the first rectifier terminal and the second rectifier terminal is Vac, the voltage of the withstand voltage capacitor CX is Vcx, the voltage drop of the first diode D1 and the second diode D2 is Vd, and the voltage of the load 500 is Vo. The following equations (1) and (2) can be obtained:

[0101] VLINE =Vac+Vcx..............Formula (1)

[0102] Vac=Vo+Vd............Formula (2)

[0103] The voltage Vo of the load 500 can be obtained by the following formula (3):

[0104]

[0105] Where R is the load resistance of 500 Ω and X is the impedance of the withstand voltage capacitor CX.

[0106] The current Io of the load 500 can be obtained by the following formula (4):

[0107]

[0108] Among them, f AC is the frequency of the external AC power supply 400, and Cx is the capacitance of the withstand voltage capacitor CX.

[0109] The output power Po of the conversion circuit can be obtained by the following formula (5):

[0110] Po=Vo*Io............Formula (5)

[0111] Combining the above equations (1), (2), (3), (4), and (5), we can obtain the following equations (6) and (7):

[0112]

[0113]

[0114] An embodiment of the present invention further provides a power conversion system, which includes a device to be powered and a power conversion circuit as described in any of the above embodiments.

[0115] It can be seen that the contents of the above-mentioned power conversion circuit embodiments are all applicable to the embodiments of this power conversion system. The functions specifically implemented by the embodiments of this power conversion system are the same as those of the above-mentioned power conversion circuit embodiments, and the beneficial effects achieved are also the same as those achieved by the above-mentioned power conversion circuit embodiments.

[0116] While the embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited to the embodiments described above. Various modifications may be made within the scope of knowledge possessed by a person skilled in the art without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof may be combined with one another unless there is a conflict.

Claims

1. A conversion circuit, characterized in that: Applied to a device to be powered, the device to be powered includes a load, the load includes a first receiving end and a second receiving end; the conversion circuit includes: a rectifier module, wherein a first rectifier terminal of the rectifier module is used to electrically connect to a first power supply terminal of an external AC power source, a second rectifier terminal of the rectifier module is used to electrically connect to a second power supply terminal of the external AC power source, and the rectifier module is further used to electrically connect to a second receiving terminal of the load; A control module, the control module being electrically connected to the rectifier module and the load, respectively, and being configured to generate an initial state signal, a first control signal, and a second control signal; wherein the rectifier module is configured to switch to an initial conduction state according to the initial state signal, so that the control module obtains an initial voltage of the load; the control module is configured to switch to a first control state according to the initial voltage and a preset first voltage threshold group; the first control signal is a signal generated by the control module in the first control state according to the actual voltage of the load and the voltage at the first rectifier end; the second control signal is a signal generated by the control module in the first control state according to the actual voltage of the load and the voltage at the second rectifier end; a switch module, the switch module being configured to be electrically connected to the first receiving end, the first rectifier end, and the second rectifier end of the load, respectively, and the switch module being configured to control a connection state between the rectifier module and the load based on a voltage at the first rectifier end, a voltage at the second rectifier end, and an actual voltage of the load, thereby controlling a connection state between the external AC power supply and the first receiving end of the load; The rectifier module is configured to switch a conduction state according to the first control signal or the second control signal to control a connection state between the external AC power source and the second receiving end of the load.

2. The conversion circuit according to claim 1, characterized in that The rectifier module includes: a first rectifier unit, the first rectifier unit being configured to be electrically connected to the control module, the first power supply end, the second power supply end, the switch module, and the second receiving end of the load, respectively, and the first rectifier unit being configured to switch a conduction state according to the first control signal or the second control signal to control a connection state between the external AC power supply and the second receiving end of the load; The second rectifier unit is used to be electrically connected to the second rectifier unit, the control module, the first power supply end, the second power supply end, the switch module, and the second receiving end of the load respectively, and the second rectifier unit is used to be shut down according to the second control signal.

3. The conversion circuit according to claim 2, characterized in that: The first rectifying unit includes: a first voltage-controlled flow element, wherein a gate of the first voltage-controlled flow element is electrically connected to the control module, a drain of the first voltage-controlled flow element is electrically connected to a first power supply terminal of the external AC power supply, a source of the first voltage-controlled flow element is electrically connected to a second receiving terminal of the load, the first voltage-controlled flow element is configured to be turned off according to the first control signal, and the first voltage-controlled flow element is configured to be turned on according to the second control signal; A second voltage-controlled flow element, the gate of the second voltage-controlled flow element is used to be electrically connected to the control module, the drain of the second voltage-controlled flow element is used to be electrically connected to the second power supply end of the external AC power supply, the source of the second voltage-controlled flow element is used to be electrically connected to the second receiving end of the load, the second voltage-controlled flow element is used to be turned on according to the first control signal, and the second voltage-controlled flow element is used to be turned off according to the second control signal.

4. The conversion circuit according to claim 3, characterized in that: The second rectifying unit includes: a first capacitor, one end of the first capacitor being electrically connected to a first power supply end of the external AC power supply; a third voltage-controlled flow element, wherein a gate of the third voltage-controlled flow element is electrically connected to the control module, a drain of the third voltage-controlled flow element is electrically connected to the other end of the first capacitor, a source of the third voltage-controlled flow element is electrically connected to the second receiving end of the load, and the third voltage-controlled flow element is configured to be shut down according to the first control signal or the second control signal; a second capacitor, one end of the second capacitor being electrically connected to the second power supply end of the external AC power supply; A fourth voltage-controlled flow element, wherein the gate of the fourth voltage-controlled flow element is used to be electrically connected to the control module, the drain of the fourth voltage-controlled flow element is used to be electrically connected to the other end of the second capacitor, the source of the fourth voltage-controlled flow element is used to be electrically connected to the second receiving end of the load, and the fourth voltage-controlled flow element is used to be shut down according to the first control signal or the second control signal.

5. The conversion circuit according to claim 4, characterized in that: The control module is further configured to generate a third control signal and a fourth control signal; the control module is configured to switch to a second control state based on the actual voltage of the load and a preset second voltage threshold group; the third control signal is a signal generated by the control module in the second control state based on the actual voltage of the load and the voltage of the first rectifier end; the fourth control signal is a signal generated by the control module in the second control state based on the actual voltage of the load and the voltage of the second rectifier end; The first pressure-controlled flow element is used to shut down according to the third control signal or the fourth control signal; the second pressure-controlled flow element is used to turn on according to the third control signal, and the second pressure-controlled flow element is used to shut down according to the fourth control signal; the third pressure-controlled flow element is used to shut down according to the third control signal, and the third pressure-controlled flow element is used to turn on according to the fourth control signal; the fourth pressure-controlled flow element is used to shut down according to the third control signal, and the fourth pressure-controlled flow element is used to turn on according to the fourth control signal.

6. The conversion circuit according to claim 5, characterized in that: The control module is further configured to generate a fifth control signal and a sixth control signal; the control module is configured to switch to a third control state or a fourth control state according to the actual voltage of the load and a preset third voltage threshold group; the fifth control signal is a signal generated by the control module in the third control state, and the sixth control signal is a signal generated by the control module in the fourth control state; The first pressure-controlled flow element is configured to be turned off according to the fifth control signal, and the first pressure-controlled flow element is configured to be turned on according to the sixth control signal; The second pressure-controlled flow element is used to shut down according to the fifth control signal, and the second pressure-controlled flow element is used to turn on according to the sixth control signal; the third pressure-controlled flow element is used to turn on according to the fifth control signal and the sixth control signal respectively; the fourth pressure-controlled flow element is used to turn on according to the fifth control signal and the sixth control signal respectively.

7. The conversion circuit according to claim 6, characterized in that: The switch module includes: a first diode, wherein an anode of the first diode is electrically connected to a first terminal of the external AC power source and a connection node of the rectifier module, and a cathode of the first diode is electrically connected to a first receiving terminal of the load; A second diode, wherein the anode of the second diode is used to be electrically connected to the second end of the external AC power supply and the connection node of the rectifier module, and the cathode of the second diode is used to be electrically connected to the first receiving end of the load.

8. The conversion circuit according to claim 7, characterized in that: The control module is further configured to generate a modulation signal, and the second rectifier unit further comprises: a third capacitor, one end of the third capacitor being electrically connected to a connection node between the third capacitor and the third voltage-controlled flow element; a fifth voltage-controlled flow element, wherein the gate of the fifth voltage-controlled flow element is used to be electrically connected to the control module, the drain of the fifth voltage-controlled flow element is used to be electrically connected to the other end of the third capacitor, the source of the fifth voltage-controlled flow element is used to be electrically connected to the second receiving end of the load, and the fifth voltage-controlled flow element is used to be turned on or off according to the modulation signal; a fourth capacitor, one end of the fourth capacitor being electrically connected to a connection node between the fourth capacitor and the fourth voltage-controlled flow element; A sixth voltage-controlled flow element, wherein the gate of the sixth voltage-controlled flow element is used to be electrically connected to the control module, the drain of the sixth voltage-controlled flow element is used to be electrically connected to the other end of the fourth capacitor, the source of the sixth voltage-controlled flow element is used to be electrically connected to the second receiving end of the load, and the sixth voltage-controlled flow element is used to be turned on or off according to the modulation signal.

9. The conversion circuit according to any one of claims 1 to 8, characterized in that: Also includes: A withstand voltage capacitor is used to be electrically connected to the first power supply end of the external AC power supply and the first rectifier end of the rectifier module respectively.

10. A power conversion system, characterized in that: include: Equipment to be powered; The conversion circuit according to any one of claims 1 to 9.

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