Power conversion circuit, power conversion method and control device

Abstract

The invention provides a power conversion circuit, a power conversion method and a control device, and the power conversion circuit comprises a filtering unit which is configured to carry out the filtering processing of an AC power supply inputted by a first input end and a second input end, and obtains a filtered AC power supply; the voltage conversion unit is configured to perform power supply conversion and voltage reduction processing on the filtered alternating current power supply to obtain a first direct current power supply; the voltage stabilizing unit is configured to perform filtering and voltage reduction processing on the first direct-current power supply to obtain a filtered second direct-current power supply; the micro-current stealing unit is configured to adjust the use frequency of the voltage stabilizing unit based on the self-oscillation principle and the high-frequency pulse characteristic to obtain a third direct-current power supply; and the power supply automatic switching unit is configured to perform comparison and power supply switching processing on the second direct-current power supply and the third direct-current power supply to obtain a target power supply.

Description

Technical Field

[0001] The present disclosure relates to the technical field of voltage converters, and more specifically, to a power conversion circuit, a power conversion method, and a control device. Background Art

[0002] With more and more hospital renovation projects, hospitals are eager for energy-saving and carbon-reduction solutions. However, air conditioners are used in special departments of hospitals, which results in a large amount of energy waste. For example, the fresh air unit is turned on at full load 24 hours a day, and the cold and heat sources cannot be intelligently allocated on demand, resulting in energy waste. Summary of the invention

[0003] The present disclosure provides a power conversion circuit, a power conversion method and a control device.

[0004] According to a first aspect of the present disclosure, a power conversion circuit is proposed, comprising: a filtering unit, electrically connected to a first input terminal and a second input terminal, configured to filter the AC power input from the first input terminal and the second input terminal to obtain a filtered AC power; a voltage conversion unit, electrically connected to the filtering unit, configured to perform power conversion and voltage reduction processing on the filtered AC power to obtain a first DC power; a voltage stabilizing unit, electrically connected to the voltage conversion unit, configured to filter and voltage reduce the first DC power to obtain a filtered second DC power; a micro-current stealing unit, electrically connected to the voltage conversion unit, configured to adjust the use frequency of the voltage stabilizing unit based on the self-oscillation principle and high-frequency pulse characteristics to obtain a third DC power; and a power automatic switching unit, electrically connected to the voltage stabilizing unit and the micro-current stealing unit, configured to compare and perform power switching processing on the second DC power and the third DC power to obtain a target power.

[0005] For example, the micro-current stealing unit includes: a first photocoupler, wherein the first end of the first photocoupler and the second end of the first photocoupler are electrically connected to the voltage conversion unit respectively; a gold farad, wherein one end of the gold farad is connected to the third end of the first photocoupler, and the other end is grounded; a first resistor, wherein one end of the first resistor is connected to the fourth end of the first photocoupler, and the other end is electrically connected to the first voltage output end; a second photocoupler, wherein the first end of the second photocoupler is electrically connected to one end of the first resistor, and the second end and the third end are respectively grounded; a first coupling inductor, wherein one end of the first coupling inductor is electrically connected to the third end of the first photocoupler; a second resistor, wherein one end of the second resistor is electrically connected to the other end of the first coupling inductor; a first transistor, wherein the gate of the first transistor is electrically connected to the other end of the second resistor, the drain is electrically connected to the other end of the first coupling inductor, and the source is grounded; a first comparator, wherein the positive input end of the first comparator is electrically connected to the drain of the first transistor, and the output end is electrically connected to the fourth end of the second photocoupler; and a first light-emitting diode, wherein one end of the first light-emitting diode is electrically connected to the first voltage output end, and the other end is electrically connected to the negative output end of the first comparator.

[0006] For example, the automatic power switching unit includes: a second comparator, the positive input terminal of the second comparator is electrically connected to the output terminal of the first comparator, and the negative input terminal is electrically connected to the voltage stabilizing unit; a third resistor, one end of the third resistor is electrically connected to the output terminal of the second comparator; a fourth resistor, one end of the fourth resistor is electrically connected to the positive input terminal of the second comparator; wherein one end of the fourth resistor is the output terminal of the target power supply; a second transistor, the gate of the second transistor is electrically connected to the other end of the third resistor, the drain is electrically connected to the other end of the fourth resistor, and the source is grounded.

[0007] For example, the filtering unit includes: a first capacitor, one end of which is electrically connected to the first input terminal; a fifth resistor, one end of which is electrically connected to the first input terminal, and the other end of which is electrically connected to the other end of the first capacitor; a fast self-recovery fuse, one end of which is electrically connected to the second input terminal; a second coupled inductor, one end of which is electrically connected to the other end of the fifth capacitor and the other end of the fast self-recovery fuse respectively, and the other end of which is electrically connected to the voltage conversion unit.

[0008] For example, the voltage conversion unit includes: a third coupled inductor, one end of which is electrically connected to the filtering unit; and a bridge, one end of which is connected to the other end of the third coupled inductor, and the other end of which is electrically connected to the micro-current stealing unit and the voltage stabilizing unit respectively.

[0009] For example, the voltage stabilizing unit includes: a second capacitor, one end of the second capacitor is electrically connected to the voltage conversion unit, and the other end is grounded; wherein, one end of the second capacitor is the first voltage output end; a third capacitor, one end of the third capacitor is electrically connected to the voltage conversion unit, and the other end is grounded; a three-terminal voltage stabilizing integrated sub-unit, a first end of the three-terminal voltage stabilizing integrated sub-unit is electrically connected to one end of the third capacitor, and the second end is grounded; a fourth capacitor, one end of the fourth capacitor is electrically connected to the third end of the three-terminal voltage stabilizing integrated sub-unit, and the other end is grounded; a fifth capacitor, one end of the fifth capacitor is electrically connected to the third end of the three-terminal voltage stabilizing integrated sub-unit, and the other end is grounded; wherein, one end of the fifth capacitor is the second voltage output end; a second light-emitting diode, one end of the second light-emitting diode is electrically connected to one end of the fifth capacitor, and the other end is electrically connected to the power automatic switching unit.

[0010] According to the second aspect of the embodiment of the present disclosure, a power conversion method is provided, which is applied to the power conversion circuit provided by the first invention of the present disclosure, including: filtering the AC power supply by a filtering unit to obtain a filtered AC power supply; using a voltage conversion unit to perform power conversion and voltage reduction processing on the filtered AC power supply to obtain a first DC power supply; using a voltage stabilizing unit to filter and voltage reduce the first DC power supply to obtain a filtered second DC power supply; using a micro-current stealing unit to adjust the use frequency of the voltage stabilizing unit based on the self-oscillation principle and high-frequency pulse characteristics to obtain a third DC power supply; and using an automatic power switching unit to compare and perform power switching processing on the second DC power supply and the third DC power supply to obtain a target power supply.

[0011] According to a third aspect of an embodiment of the present disclosure, a control device is provided, comprising: the power conversion circuit provided by the first aspect of the embodiment of the present disclosure.

[0012] For example, the device also includes: a temperature and humidity detection module, which is used to collect temperature data and humidity data in each room of the hospital; a main controller, which is electrically connected to the power conversion circuit and the temperature and humidity detection module, respectively, and is used to process the temperature data and humidity data and output power control instructions when the DC power supply provided by the power conversion circuit is powered; an auxiliary controller, which is electrically connected to the main controller, and is used to output a power control signal according to the power control instruction; a zero-crossing detection circuit, which is electrically connected to the power conversion circuit and the auxiliary controller, and is used to capture the operating frequency and zero-crossing time of the mains; wherein the operating frequency and zero-crossing time are used for the working clock synchronization signal of the zero-crossing detection circuit, the auxiliary controller and the thyristor frequency conversion circuit; and the thyristor frequency conversion circuit, which is electrically connected to the auxiliary controller, and is used to adjust the output power of the load according to the power control signal.

[0013] For example, the zero-crossing detection circuit includes: a sixth resistor, one end of the sixth resistor is electrically connected to the first AC power input terminal; a seventh resistor, one end of the sixth resistor is electrically connected to the second AC power input terminal; a rectifier bridge, a first end of the rectifier bridge is connected to the other end of the sixth resistor, and a second end is electrically connected to the other end of the seventh resistor; a third photoelectric coupler, a first end of the third photoelectric coupler is electrically connected to the third end of the rectifier bridge, and a second end is electrically connected to the fourth end of the rectifier bridge; wherein the third end of the third photoelectric coupler is the first target voltage output terminal; the fourth end of the third photoelectric coupler is the second target voltage output terminal; an eighth resistor, one end of the eighth resistor is electrically connected to the fourth end of the third photoelectric coupler, and the other end is grounded.

[0014] According to the technical solution of the disclosed embodiment, a power conversion circuit, a power conversion method and a control device are provided. The circuit converts and reduces the voltage of an AC power supply through a voltage conversion unit to obtain a low-amplitude DC power supply, and processes the low-amplitude DC power supply through a voltage stabilization, micro-current stealing and power automatic switching unit to obtain a target power supply that is a low-amplitude stable DC power supply. The target power supply can provide working power for the main controller after the 220V power supply is disconnected, thereby achieving the purpose of energy saving. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and other purposes, features and advantages of the embodiments of the present disclosure will be made clearer by describing the embodiments of the present disclosure in conjunction with the accompanying drawings. It should be noted that throughout the accompanying drawings, the same elements are represented by the same or similar reference numerals. In the drawings:

[0016] Figure 1 A schematic diagram of the structure of a power conversion circuit according to an embodiment of the present disclosure is shown;

[0017] Figure 2 A schematic structural diagram of a power conversion circuit according to another embodiment of the present disclosure is shown;

[0018] Figure 3 A flow chart of a power conversion method according to an embodiment of the present disclosure is shown;

[0019] Figure 4 A schematic diagram showing the structure of a control device according to an embodiment of the present disclosure is shown; and

[0020] Figure 5 A schematic structural diagram of a zero-crossing detection circuit according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of them. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present disclosure. In the following description, some specific embodiments are only used for descriptive purposes and should not be understood as any limitation to the present disclosure, but are only examples of the embodiments of the present disclosure. Conventional structures or constructions will be omitted when they may cause confusion in the understanding of the present disclosure. It should be noted that the shapes and sizes of the components in the figures do not reflect the actual size and proportion, but only illustrate the contents of the embodiments of the present disclosure.

[0022] Unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present disclosure should have the usual meanings understood by those skilled in the art. The words "first", "second" and similar words used in the embodiments of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components.

[0023] In addition, in the description of the embodiments of the present disclosure, the term "connected to" or "connected" may refer to two components being directly connected, or may refer to two components being connected via one or more other components, and the connection method is electrical connection or electrical coupling. In addition, the two components may also be connected or coupled by wire or wirelessly.

[0024] According to their different functions, the capacitor used in the embodiment of the present disclosure may be an adjustable capacitor device, and the resistor used may be an adjustable resistor device. In the example of the present disclosure, the capacitor and the resistor may be assumed to be adjustable, and no further description will be given below.

[0025] Hereinafter, various embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. It should be noted that in the accompanying drawings, the same reference numerals are given to components having substantially the same or similar structures and functions, and repeated descriptions thereof will be omitted.

[0026] Figure 1 A schematic structural diagram of a power conversion circuit according to an embodiment of the present disclosure is shown.

[0027] like Figure 1 As shown, the power conversion circuit 100 includes a filtering unit 110 , a voltage conversion unit 120 , a voltage stabilizing unit 130 , a micro-current stealing unit 140 and a power automatic switching unit 150 .

[0028] The filter unit 110 is electrically connected to the first input terminal and the second input terminal, and is configured to filter the AC power input from the first input terminal and the second input terminal to obtain a filtered AC power.

[0029] The voltage conversion unit 120 is electrically connected to the filtering unit 110 and is configured to perform power conversion and voltage reduction processing on the filtered AC power to obtain a first DC power.

[0030] The voltage stabilizing unit 130 is electrically connected to the voltage converting unit 120 and is configured to filter and reduce the voltage of the first DC power supply to obtain a filtered second DC power supply.

[0031] The micro-current stealing unit 140 is electrically connected to the voltage conversion unit 120, and is configured to adjust the use frequency of the voltage stabilizing unit based on the self-oscillation principle and high-frequency pulse characteristics to obtain a third DC power supply.

[0032] The power automatic switching unit 150 is electrically connected to the voltage stabilizing unit 120 and the micro-current stealing unit 140, and is configured to compare the second DC power supply and the third DC power supply and perform power switching processing to obtain a target power supply.

[0033] According to an embodiment of the present disclosure, the circuit converts and steps down an AC power supply through a voltage conversion unit to obtain a low-amplitude DC power supply, and processes the low-amplitude DC power supply through a voltage stabilization, micro-current stealing, and automatic power switching unit to obtain a target power supply that is a low-amplitude stable DC power supply. The target power supply can be used to power a main controller, thereby achieving energy saving.

[0034] Figure 2 A schematic structural diagram of a power conversion circuit according to another embodiment of the present disclosure is shown.

[0035] like Figure 2 As shown, the power conversion circuit 200 includes a filter unit 210 , a voltage conversion unit 220 , a voltage stabilization unit 230 , a micro-current stealing unit 240 and a power automatic switching unit 250 .

[0036] It should be noted that the filter unit 210, the voltage conversion unit 220, the voltage stabilization unit 230, the micro-current stealing unit 240, the power automatic switching unit 250 and Figure 1 The functions of the filter unit 110, the voltage conversion unit 120, the voltage stabilization unit 130, the micro-current stealing unit 140 and the power automatic switching unit 150 shown are the same, and for the sake of simplicity, they are not repeated here.

[0037] like Figure 2 As shown, the filtering unit 210 may include a first capacitor C1, a fifth resistor R5, a fast self-recovery fuse R and a second coupled inductor.

[0038] Specifically, one end of the first capacitor C1 is electrically connected to the first input terminal INPUT1, and the other end is electrically connected to one end of the second coupling inductor. The fifth resistor R5 is connected in parallel with the first capacitor C1, that is, one end of the fifth resistor R5 is electrically connected to the first input terminal INPUT1, and the other end is electrically connected to one end of the second coupling inductor. One end of the fast self-recovery fuse R is electrically connected to the second input terminal INPUT2, and the other end is electrically connected to one end of the second coupling inductor. The other end of the second coupling inductor is electrically connected to the voltage conversion unit 220.

[0039] For example, the second coupled inductor may be a coupled inductor formed by combining inductors L3 and L4.

[0040] like Figure 2 As shown, the filtering unit 210 may include a third coupled inductor and a bridge D.

[0041] Specifically, one end of the third coupled inductor is electrically connected to the filter unit 210 , and the other end is electrically connected to the bridge D. The bridge D is electrically connected to the voltage stabilizing unit 230 and the micro-current stealing unit 240 , respectively.

[0042] For example, the third coupled inductor may be a coupled inductor formed by combining inductors L5 and L6.

[0043] For example, the bridge D may be a bridge type bridge composed of four diodes.

[0044] like Figure 2 As shown, the voltage stabilizing unit 230 may include a second capacitor C2, a third capacitor C3, a three-terminal voltage stabilizing integrated sub-unit 7805, a fourth capacitor C4, a fifth capacitor C5 and a second light emitting diode LED2.

[0045] Specifically, one end of the second capacitor C2 is electrically connected to the bridge D, and the other end is grounded, wherein one end of the second capacitor C2 is the first voltage output terminal V1. One end of the third capacitor C3 is electrically connected to the bridge D, and the other end is grounded. The first end of the three-terminal voltage stabilizing integrated subunit 7805 is electrically connected to one end of the third capacitor C1, the second end is grounded, and the third end is electrically connected to one end of the fourth capacitor C4. The other end of the fourth capacitor C4 is grounded. One end of the fifth capacitor C5 is electrically connected to one end of the fourth capacitor C4, and the other end is grounded. One end of the second light emitting diode LED2 is electrically connected to one end of the fifth capacitor C5, and the other end is electrically connected to the power automatic switching unit 250.

[0046] It can be understood that the first end of the three-terminal voltage stabilization integrated sub-unit 7805 is the voltage input terminal IN, the second end is the ground line GND, and the third end is the voltage stabilization output terminal OUT, which is used to stabilize the low-amplitude DC power output by the voltage conversion unit 220.

[0047] For example, the second capacitor C2 is an electrolytic capacitor, the third capacitor C3 is a monolithic capacitor, the fourth capacitor C4 is a monolithic capacitor, and the fifth capacitor C5 is an electrolytic capacitor.

[0048] like Figure 2 As shown, the micro-current stealing unit 240 may include a first photocoupler TP521, a gold farad F, a first resistor R1, a second photocoupler TP521, a first coupling inductor, a second resistor R2, a first transistor, a first comparator, and a first light-emitting diode LED1.

[0049] Specifically, the first end and the second end of the first photocoupler TP521 are electrically connected to the bridge D of the voltage conversion unit, respectively, and the third end is electrically connected to one end of the gold farad F. The other end of the gold farad F is grounded. One end of the first resistor is connected to the fourth end of the first photocoupler TP521, and the other end is electrically connected to the first voltage output terminal V1. The first end of the second photocoupler TP521 is electrically connected to one end of the first resistor R1, and the second end and the third end are grounded respectively. One end of the first coupling inductor is electrically connected to the third end of the first photocoupler TP521, and the other end is electrically connected to one end of the second resistor and the drain of the first transistor, respectively. One end of the second resistor R2 is electrically connected to the other end of the first coupling inductor, and the other end is electrically connected to the gate of the first transistor. The source of the first transistor is grounded. The positive input end of the first comparator is electrically connected to the drain of the first transistor, and the output end is electrically connected to the fourth end of the second photocoupler TP512. One end of the first light-emitting diode is electrically connected to the first voltage output terminal V1, and the other end is electrically connected to the negative output end of the first comparator.

[0050] For example, the first transistor may be an NPN transistor.

[0051] For example, the first light emitting diode may be a red light emitting diode for lighting up for prompting.

[0052] like Figure 2 As shown, the power automatic switching unit 250 includes a second comparator, a third resistor R3, a fourth resistor R4 and a second transistor.

[0053] Specifically, the positive input terminal of the second comparator is electrically connected to the output terminal of the first comparator, and the negative input terminal is electrically connected to the second light emitting diode LED2 of the voltage stabilizing unit. One end of the third resistor R3 is electrically connected to the output terminal of the second comparator. One end of the fourth resistor R4 is electrically connected to the positive input terminal of the second comparator, wherein one end of the fourth resistor R4 is the output terminal OUTPUT of the target power supply. The gate of the second transistor is electrically connected to the other end of the third resistor R3, the drain is electrically connected to the other end of the fourth resistor R4, and the source is grounded.

[0054] For example, the second transistor may be an NPN transistor.

[0055] According to an embodiment of the present disclosure, the filter unit 210 is a complex filter unit composed of capacitors and inductors. The filter unit 210 can be used to filter the 220VAC alternating current, specifically filtering high-frequency ripples and reducing low-frequency ripples and common-mode ripples through a dual-channel common-mode mutual inductor to obtain a low-ripple 220VAC alternating current power supply. The low-ripple 220VAC alternating current power supply is converted into voltage amplitude and electrical characteristics by the voltage conversion unit 220 to obtain a low-amplitude direct current (i.e., V1).

[0056] For example, the low-amplitude direct current V1 output by the voltage conversion unit 220 may be a direct current of 11.7V.

[0057] For example, the low-amplitude DC power output by the voltage conversion unit 220 is filtered and reduced by the voltage stabilization unit to obtain a DC regulated voltage (ie, V2) with an amplitude of 4.7 V. The DC regulated voltage with an amplitude of 4.7 V is a pure DC power supply.

[0058] For example, the low-amplitude direct current output by the voltage conversion unit 220 is subjected to micro-current stealing by the micro-current stealing unit 240. Specifically, when the voltage of the farad capacitor F is lower than 11.7V, the farad capacitor F is in a charging state. After the farad capacitor F is charged to exceed the threshold, the charging circuit will be automatically disconnected and the farad capacitor F will enter a discharging state for supplying the subsequent MCU unit. After being discharged to the lowest voltage, charging will be started again, and the cycle will continue.

[0059] For example, the second DC power output by the voltage stabilizing unit 230 and the third DC power output by the micro-current stealing unit 240 are compared and switched by the power automatic switching unit 250 to obtain a target power supply. The target power supply can be a stable DC power supply with an amplitude of 5V, which is used to power the main controller.

[0060] According to the embodiment of the present disclosure, the micro-current stealing unit 240 in the power conversion circuit 200 obtains a great energy-saving effect by intercepting the energy consumption of capacitor charging through a dual comparison circuit.

[0061] According to an embodiment of the present disclosure, a power conversion method for the power conversion circuit shown in the above embodiment is also provided. Figure 3 FIG. 1 is a flow chart of a power conversion method according to an embodiment of the present disclosure. Figure 3 As shown, the power conversion method according to the embodiment of the present disclosure may include the following steps. It should be noted that the sequence numbers of the steps in the following method are only used as representations of the steps for the purpose of description, and should not be regarded as indicating the execution order of the steps. Unless explicitly stated, the method does not need to be executed completely in the order shown.

[0062] In step S310, the filter unit performs filtering processing on the AC power to obtain a filtered AC power.

[0063] In step S320, the filtered AC power is converted and stepped down by a voltage conversion unit to obtain a first DC power.

[0064] In step S330, the first DC power source is filtered and reduced in voltage by using a voltage stabilizing unit to obtain a filtered second DC power source.

[0065] In step S340, the micro-current stealing unit adjusts the operating frequency of the voltage stabilizing unit based on the self-oscillation principle and the high-frequency pulse characteristics to obtain a third DC power supply.

[0066] In step S350, the automatic power switching unit compares the second DC power source and the third DC power source and performs power switching processing to obtain a target power source.

[0067] It should be noted that the method provided by the present disclosure is implemented based on the power conversion circuit shown in the above embodiment. The specific structures of the filtering unit, voltage conversion unit, voltage stabilization unit, micro-current stealing unit and power automatic switching unit in the method are as shown in the above embodiment. Figure 1 , 2 As shown, no further description is given here.

[0068] According to the embodiment of the present disclosure, Figure 4 As shown, a control device 400 is also provided, including: Figure 1 or Figure 2 The power conversion circuit shown.

[0069] It should be noted that the power conversion circuit 410 included in the control device 400, the specific structures of the components of the circuit in the power conversion circuit 410, such as the filtering unit, the voltage conversion unit, the voltage stabilizing unit, the micro-current stealing unit and the power automatic switching unit are as shown in the above embodiment, for example, Figure 1 or Figure 2 For the sake of simplicity, it will not be described here.

[0070] like Figure 4 As shown, the control device 400 further includes a temperature and humidity detection module 420 , a main controller (MCU) 430 , an auxiliary controller 440 , a zero-crossing detection circuit 450 and a thyristor frequency conversion circuit 460 .

[0071] The temperature and humidity detection module 420 is used to collect temperature data and humidity data in the clean room of the hospital.

[0072] The main controller 430 is electrically connected to the power conversion circuit 410 and the temperature and humidity detection module 420 respectively, and is used to process the temperature data and humidity data and output power control instructions when the power conversion circuit 410 is powered by a DC power supply.

[0073] The auxiliary controller 440 is electrically connected to the main controller 430, and is used to output a power control signal according to the power control instruction.

[0074] The zero-crossing detection circuit 450 is electrically connected to the power conversion circuit 410 and the auxiliary controller 440, respectively, and is used to capture the operating frequency and zero-crossing time of the mains power; wherein the operating frequency and zero-crossing time are used as the working clock synchronization signal of the zero-crossing detection circuit, the auxiliary controller and the thyristor frequency conversion circuit.

[0075] The thyristor frequency conversion circuit 460 is electrically connected to the auxiliary controller 440 and is used to adjust the output power of the load according to the power control signal.

[0076] According to an embodiment of the present disclosure, the specific structure of the zero-crossing detection circuit 450 is as follows: Figure 5 The zero-crossing detection circuit 450 may include a sixth resistor R6, a seventh resistor R7, a rectifier bridge DB107, a third photocoupler TP521 and an eighth resistor R8.

[0077] Specifically, one end of the sixth resistor R6 is electrically connected to the first mains input terminal. One end of the seventh resistor R7 is electrically connected to the second mains input terminal. The first end of the rectifier bridge DB107 is connected to the other end of the sixth resistor R6, and the second end is electrically connected to the other end of the seventh resistor R7. The first end of the third photocoupler TP521 is electrically connected to the third end of the rectifier bridge DB107, and the second end is electrically connected to the fourth end of the rectifier bridge DB107. Among them, the third end of the third photocoupler TP521 is the output end of the first target voltage OUTPUT1, and the fourth end is the output end of the second target voltage OUTPUT2. One end of the eighth resistor R8 is electrically connected to the fourth end of the third photocoupler TP521, and the other end is grounded.

[0078] In the disclosed embodiment, the zero-crossing detection circuit 450 is current-limited by two KW-level carbon film resistors to prevent the circuit from burning. The rectifier bridge DB107 is a 1000V1A rectifier bridge that can output about 380V DC. When the zero point comes, the third photocoupler TP521 is turned on, and the automatic reset circuit rises to a high level, so that the MCU can accurately capture each zero point.

[0079] In the embodiment of the present disclosure, the load adjusted by the thyristor frequency conversion circuit 460 may be air conditioners used in various departments and clean rooms of a hospital, or other equipment including a main controller.

[0080] For example, the control device can also be electrically connected to a local host computer through the serial port of the main controller to perform data interaction processing, and the host computer can display various data, switch control functions of the device, data statistics functions, data analysis and recording functions, etc. In addition, data forwarding can be achieved through the IoT cloud platform to achieve the purpose of full network control.

[0081] It should be noted that, in the above description, the technical solution of the embodiment of the present disclosure is shown only by way of example, but it does not mean that the embodiment of the present disclosure is limited to the above steps and structures. Where possible, the steps and structures can be adjusted and selected as needed. Therefore, some steps and units are not necessary elements for implementing the overall inventive concept of the embodiment of the present disclosure.

[0082] The present disclosure has been described so far in conjunction with the preferred embodiments. It should be understood that those skilled in the art may make various other changes, substitutions and additions without departing from the spirit and scope of the embodiments of the present disclosure. Therefore, the scope of the embodiments of the present disclosure is not limited to the above-mentioned specific embodiments, but should be limited by the appended claims.

Claims

1. A power conversion circuit, characterized in that: include: a filter unit, electrically connected to the first input terminal and the second input terminal, configured to filter the AC power input from the first input terminal and the second input terminal to obtain a filtered AC power; a voltage conversion unit, electrically connected to the filtering unit, and configured to perform power conversion and voltage reduction processing on the filtered AC power supply to obtain a first DC power supply; a voltage stabilizing unit, electrically connected to the voltage conversion unit, and configured to filter and reduce the voltage of the first DC power supply to obtain a filtered second DC power supply; a micro-current stealing unit, electrically connected to the voltage conversion unit, and configured to adjust the use frequency of the voltage stabilizing unit based on the self-oscillation principle and high-frequency pulse characteristics to obtain a third DC power supply; and The power automatic switching unit is electrically connected to the voltage stabilizing unit and the micro-current stealing unit, and is configured to compare the second DC power supply and the third DC power supply and perform power switching processing to obtain a target power supply.

2. The power conversion circuit according to claim 1, characterized in that: The micro-current stealing unit comprises: A first photoelectric coupler, wherein a first end of the first photoelectric coupler and a second end of the first photoelectric coupler are electrically connected to the voltage conversion unit respectively; A gold farad, one end of which is connected to the third end of the first photoelectric coupler, and the other end of which is grounded; a first resistor, one end of the first resistor being connected to the fourth end of the first photoelectric coupler, and the other end of the first resistor being electrically connected to the first voltage output end; A second photoelectric coupler, wherein a first end of the second photoelectric coupler is electrically connected to one end of the first resistor, and a second end and a third end of the second photoelectric coupler are grounded respectively; a first coupling inductor, wherein one end of the first coupling inductor is electrically connected to the third end of the first photoelectric coupler; a second resistor, one end of the second resistor being electrically connected to the other end of the first coupling inductor; a first transistor, wherein a gate of the first transistor is electrically connected to the other end of the second resistor, a drain of the first transistor is electrically connected to the other end of the first coupling inductor, and a source of the first transistor is grounded; a first comparator, wherein a positive input terminal of the first comparator is electrically connected to the drain of the first transistor, and an output terminal of the first comparator is electrically connected to the fourth terminal of the second photocoupler; and A first light emitting diode, wherein one end of the first light emitting diode is electrically connected to the first voltage output end, and the other end of the first light emitting diode is electrically connected to the negative output end of the first comparator.

3. The power conversion circuit according to claim 2, characterized in that: The power automatic switching unit comprises: A second comparator, wherein a positive input terminal of the second comparator is electrically connected to the output terminal of the first comparator, and a negative input terminal of the second comparator is electrically connected to the voltage stabilizing unit; a third resistor, one end of the third resistor being electrically connected to the output end of the second comparator; a fourth resistor, one end of which is electrically connected to the positive input end of the second comparator; wherein one end of the fourth resistor is the output end of the target power supply; and A second transistor, wherein the gate of the second transistor is electrically connected to the other end of the third resistor, the drain of the second transistor is electrically connected to the other end of the fourth resistor, and the source of the second transistor is grounded.

4. The power conversion circuit according to claim 1, characterized in that: The filtering unit comprises: A first capacitor, one end of the first capacitor being electrically connected to the first input end; a fifth resistor, one end of the fifth resistor being electrically connected to the first input end, and the other end of the fifth resistor being electrically connected to the other end of the first capacitor; a fast self-resetting fuse, one end of which is electrically connected to the second input end; and A second coupled inductor, one end of which is electrically connected to the other end of the fifth capacitor and the other end of the fast self-recovery fuse respectively, and the other end of which is electrically connected to the voltage conversion unit.

5. The power conversion circuit according to claim 1, characterized in that: The voltage conversion unit comprises: a third coupled inductor, one end of which is electrically connected to the filtering unit; and An electric bridge, one end of which is connected to the other end of the third coupled inductor, and the other end of which is electrically connected to the micro-current stealing unit and the voltage stabilizing unit respectively.

6. The power conversion circuit according to claim 1, characterized in that: The voltage stabilizing unit comprises: A second capacitor, one end of which is electrically connected to the voltage conversion unit and the other end of which is grounded; wherein one end of the second capacitor is a first voltage output end; A third capacitor, one end of which is electrically connected to the voltage conversion unit, and the other end of which is grounded; A three-terminal voltage stabilizing integrated sub-unit, wherein a first terminal of the three-terminal voltage stabilizing integrated sub-unit is electrically connected to one terminal of the third capacitor, and a second terminal is grounded; a fourth capacitor, one end of which is electrically connected to the third end of the three-terminal voltage-stabilizing integrated sub-unit, and the other end of which is grounded; a fifth capacitor, one end of which is electrically connected to the third end of the three-terminal voltage-stabilizing integrated sub-unit, and the other end of which is grounded; wherein one end of the fifth capacitor is the second voltage output end; and A second light emitting diode, wherein one end of the second light emitting diode is electrically connected to one end of the fifth capacitor, and the other end of the second light emitting diode is electrically connected to the automatic power switching unit.

7. A power conversion method, characterized in that: The method is applied to the power conversion circuit according to any one of claims 1 to 6, comprising: The filter unit performs filtering processing on the AC power supply to obtain a filtered AC power supply; Using a voltage conversion unit to perform power conversion and voltage reduction processing on the filtered AC power supply to obtain a first DC power supply; Using a voltage stabilizing unit to filter and reduce the voltage of the first DC power supply to obtain a filtered second DC power supply; The micro-current stealing unit adjusts the use frequency of the voltage stabilizing unit based on the self-oscillation principle and high-frequency pulse characteristics to obtain a third DC power supply; and The automatic power switching unit compares the second DC power supply and the third DC power supply and performs power switching processing to obtain a target power supply.

8. A control device, characterized in that: include: The power conversion circuit according to any one of claims 1 to 6, wherein the power conversion circuit is used to convert an AC power source into a DC power source.

9. The control device according to claim 8, characterized in that: The device also includes: Temperature and humidity detection module, used to collect temperature and humidity data in each room of the hospital; A main controller, electrically connected to the power conversion circuit and the temperature and humidity detection module, respectively, for processing the temperature data and the humidity data and outputting a power control instruction when the DC power supply provided by the power conversion circuit is powered; an auxiliary controller, electrically connected to the main controller, and configured to output a power control signal according to the power control instruction; A zero-crossing detection circuit is electrically connected to the power conversion circuit and the auxiliary controller, respectively, and is used to capture the operating frequency and zero-crossing time of the mains; wherein the operating frequency and the zero-crossing time are used as the working clock synchronization signal of the zero-crossing detection circuit, the auxiliary controller and the thyristor frequency conversion circuit; and The thyristor frequency conversion circuit is electrically connected to the auxiliary controller and is used to adjust the output power of the load according to the power control signal.

10. The control device according to claim 9, characterized in that: The zero-crossing detection circuit comprises: a sixth resistor, one end of which is electrically connected to the first mains input terminal; a seventh resistor, one end of which is electrically connected to the second mains input terminal; a rectifier bridge, wherein a first end of the rectifier bridge is connected to the other end of the sixth resistor, and a second end of the rectifier bridge is electrically connected to the other end of the seventh resistor; a third photoelectric coupler, wherein a first end of the third photoelectric coupler is electrically connected to a third end of the rectifier bridge, and a second end of the third photoelectric coupler is electrically connected to a fourth end of the rectifier bridge; wherein the third end of the third photoelectric coupler is a first target voltage output end; and the fourth end of the third photoelectric coupler is a second target voltage output end; and An eighth resistor, one end of the eighth resistor is electrically connected to the fourth end of the third photoelectric coupler, and the other end of the eighth resistor is grounded.

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