Thyristor-based input rectification protection circuit and control method thereof

Abstract

The application belongs to the technical field of chargers, and particularly relates to an input rectification protection circuit based on thyristors and a control method thereof, which comprises a commercial power access circuit and a PFC circuit, and further comprises: an input detection circuit, a main control circuit, the main control circuit comprising a main control chip, the main control chip being connected with the input detection circuit and being used for acquiring an input voltage detected by the input detection circuit; a rectification circuit, the rectification circuit being connected with the commercial power access circuit and the main control chip, the rectification circuit being further connected with the PFC circuit, so that the main control chip sends an electric signal to the rectification circuit when the input voltage exceeds a preset normal voltage range, so that the rectification circuit filters out the voltage exceeding the preset normal voltage range in the input voltage and then outputs. The application on one hand realizes the setting of no input relay, thereby reducing the cost, and on the other hand realizes that the charger can still work in the case that the commercial power voltage is too high.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of chargers, and particularly relates to an input rectification protection circuit based on thyristors and a control method thereof. BACKGROUND

[0002] The charger is a charging device adopting high-frequency power supply technology and using advanced intelligent dynamic adjustment charging technology. The charger (charging machine) can be divided into a power frequency machine and a high-frequency machine according to the working frequency of the designed circuit. The power frequency machine is designed based on the traditional analog circuit principle, and the internal power devices (such as transformers, inductors, capacitors, etc.) are relatively large. When the machine is in operation with a large load, a small noise exists, but the machine model has strong resistance to adverse power grid environment conditions, and the reliability and stability are stronger than those of the high-frequency machine.

[0003] At present, in the common charger suitable for the global range, the normal input voltage is 85V-265V. When the input voltage is in this range, the charger can work normally. However, when the input voltage is higher than 270V, many chargers will be damaged. In view of this scenario, a common method is to add an input relay at the input end. When it is detected that the input voltage is too high, the input relay is popped open, thereby protecting the subsequent components from being damaged by high voltage. At this time, the charger no longer works, which leads to two problems. One is that each charger needs to set an input relay to cause a cost problem. The other is that once the input relay is popped open due to high voltage, the charger cannot work, which affects use.

[0004] Therefore, it is necessary to design an input rectification protection circuit based on thyristors and a control method thereof. SUMMARY

[0005] The application aims to provide an input rectification protection circuit based on thyristors and a control method thereof, and aims to solve the technical problems in the prior art that the charger sets an input relay to cause high cost and the charger cannot work due to the input relay being popped open at high voltage.

[0006] To achieve the above-mentioned purpose, the application provides an input rectification protection circuit based on thyristors, which comprises a commercial power access circuit and a PFC circuit, and further comprises:

[0007] An input detection circuit, which is connected with the commercial power access circuit and is used for detecting the input voltage of the commercial power access circuit;

[0008] A main control circuit, which comprises a main control chip, is connected with the input detection circuit, and is used for acquiring the input voltage detected by the input detection circuit;

[0009] A rectifier circuit is connected with the mains access circuit and the main control chip, and is also connected with the PFC circuit, so that the main control chip sends an electrical signal to the rectifier circuit when the input voltage exceeds the preset normal voltage range, and the rectifier circuit filters out the voltage exceeding the preset normal voltage range in the input voltage and outputs.

[0010] Optionally, the rectifier circuit comprises a second diode, a first thyristor, a second thyristor and a third diode, the cathode of the second diode is connected with the mains access circuit, the anode of the first thyristor is connected with the cathode of the second diode, the cathode of the second thyristor is connected with the cathode of the first thyristor, the anode of the third diode is connected with the anode of the second thyristor, the anode of the third diode is connected with the anode of the second diode, and the anode of the third diode and the anode of the second diode are also connected with the PFC circuit; the cathode of the third diode and the anode of the second thyristor are also connected with the mains access circuit.

[0011] The control electrode of the first thyristor and the control electrode of the second thyristor are connected with the main control chip.

[0012] Optionally, the rectifier circuit comprises a second diode, a first thyristor, a second thyristor and a third diode, the cathode of the second diode is connected with the mains access circuit, the anode of the first thyristor is connected with the cathode of the second diode, the cathode of the second thyristor is connected with the cathode of the first thyristor, the anode of the third diode is connected with the anode of the second thyristor, the anode of the third diode is connected with the anode of the second diode, and the anode of the third diode and the anode of the second diode are also connected with the PFC circuit; the cathode of the third diode and the anode of the second thyristor are also connected with the mains access circuit.

[0013] Optionally, the first thyristor driving circuit comprises a first optocoupler, an eleventh transistor and a second resistor, the first pin of the first optocoupler is connected with a first power supply end, the collector of the eleventh transistor is connected with the second pin of the first optocoupler, the base of the eleventh transistor is connected with the first pin of the main control chip, the fourth pin of the first optocoupler is connected with a second power supply end, the second resistor is connected with the third pin of the first optocoupler, and the second resistor is also connected with the control electrode of the first thyristor.

[0014] Optionally, the second thyristor driving circuit comprises a second optocoupler, a fifteenth transistor and a first resistor, the first pin of the second optocoupler is connected with a first power supply end, the collector of the fifteenth transistor is connected with the second pin of the second optocoupler, the base of the fifteenth transistor is connected with the second pin of the main control chip, the fourth pin of the first optocoupler is connected with a second power supply end, the first resistor is connected with the third pin of the second optocoupler, and the first resistor is also connected with the control electrode of the second thyristor.

[0015] Optionally, the input detection circuit comprises a voltage detection circuit and a phase detection circuit, the voltage detection circuit is connected with the mains access circuit, the phase detection circuit is connected with the voltage detection circuit, and the voltage detection circuit and the phase detection circuit are both connected with the master control chip.

[0016] Optionally, the voltage detection circuit comprises a first operational amplifier and a second operational amplifier, the input ends of the first operational amplifier and the second operational amplifier are connected with the mains access circuit, the output end of the second operational amplifier is connected with the output end of the first operational amplifier, and the output ends of the first operational amplifier and the second operational amplifier are both connected with the fourteenth pin of the master control chip.

[0017] Optionally, the phase detection circuit comprises a fourteenth transistor, the base of the fourteenth transistor is connected with the output end of the second operational amplifier, and the emitter of the fourteenth transistor is connected with the nineteenth pin of the master control chip and the first power supply end.

[0018] The above one or more technical solutions in the input rectification protection circuit based on silicon controlled rectifier provided by the embodiment of the present application at least have one of the following technical effects:

[0019] The input detection circuit is arranged to detect the input voltage of the mains access circuit, the master control chip is arranged to judge the input voltage, and when the input voltage exceeds the preset normal voltage range, the electric signal is sent to the rectifier circuit, and the rectifier circuit is controlled based on the electric signal to filter out the voltage exceeding the preset normal voltage range in the input voltage and then output, so that the input relay is not needed to be arranged, the cost is reduced, and the high voltage is filtered out, so that the charger does not work directly under the high voltage, the charger can work under the high voltage, and the use convenience is greatly improved.

[0020] To achieve the above object, the embodiment of the present application provides a control method of an input rectification protection circuit based on silicon controlled rectifier, which comprises the following steps:

[0021] Step S100: the input detection circuit detects the input voltage of the mains access circuit;

[0022] Step S200: the master control chip acquires the input voltage detected by the input detection circuit, and judges whether the input voltage exceeds the preset normal voltage range according to the input voltage;

[0023] Step S300: If the judgment is yes, the main control chip controls the first thyristor and the second thyristor to be turned on according to a preset thyristor turn-on point when the input voltage drops to a preset normal voltage range, so that the rectifier circuit outputs after filtering the voltage exceeding the preset normal voltage range in the input voltage.

[0024] The control method of the input rectification protection circuit based on the thyristor provided by the embodiment of the present application has at least one of the following technical effects:

[0025] The control method of the input rectification protection circuit based on the thyristor provided by the embodiment of the present application has at least one of the following technical effects: BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0027] Figure 1 The overall circuit schematic diagram of the input rectification protection circuit based on the thyristor provided by the embodiment of the present application;

[0028] Figure 2 The circuit schematic diagram of the main control circuit provided by the embodiment of the present application;

[0029] Figure 3 The combined circuit schematic diagram of the input detection circuit, the PFC circuit, the rectifier circuit, the first thyristor driving circuit and the second thyristor driving circuit provided by the embodiment of the present application;

[0030] Figure 4 The circuit schematic diagram of the input detection circuit provided by the embodiment of the present application;

[0031] Figure 5A circuit diagram of the auxiliary power supply circuit provided in an embodiment of the present invention;

[0032] Figure 6 A schematic flowchart illustrating the control method for the input rectifier protection circuit based on silicon controlled rectifiers provided in this embodiment of the invention.

[0033] The following are the labeling elements in the figure:

[0034] 100. Mains power input circuit; 200. PFC circuit;

[0035] 300. Input detection circuit; 310. Voltage detection circuit; 320. Phase detection circuit;

[0036] 400. Main control circuit; 410. First thyristor drive circuit; 420. Second thyristor drive circuit; 500. Rectifier circuit; 600. Auxiliary power supply circuit. Detailed Implementation

[0037] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain embodiments of the present invention, and should not be construed as limiting the present invention.

[0038] In the description of the embodiments of the present invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of 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, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0039] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of the present invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0040] In the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances.

[0041] In one embodiment of the present invention, such as Figure 1 As shown, an input rectification protection circuit based on a silicon controlled rectifier (SCR) is provided, including a mains power access circuit 100 and a PFC circuit 200. The mains power access circuit 100 is used to connect to mains power.

[0042] The input rectification protection circuit based on thyristors also includes an input detection circuit 300, a main control circuit 400, and a rectifier circuit 500.

[0043] The input detection circuit 300 is connected to the mains power access circuit 100 and is used to detect the input voltage of the mains power access circuit 100; the main control circuit 400 includes a main control chip U6, which is connected to the input detection circuit 300 and is used to acquire the input voltage detected by the input detection circuit 300; the rectifier circuit 500 is connected to both the mains power access circuit 100 and the main control chip U6, and is also connected to the PFC circuit 200, so that when the input voltage exceeds the preset normal voltage range, the main control chip U6 sends an electrical signal to the rectifier circuit 500, so that the rectifier circuit 500 filters out the voltage exceeding the preset normal voltage range from the input voltage and outputs it.

[0044] The preset normal voltage range is pre-set, such as 85V-265V.

[0045] This invention first detects the input voltage of the mains power access circuit 100 by setting the input detection circuit 300, and then sets the main control chip to judge the input voltage. When the input voltage exceeds the preset normal voltage range, an electrical signal is sent to the rectifier circuit 500. Based on the electrical signal, the rectifier circuit 500 is controlled to filter out the voltage exceeding the preset normal voltage range before outputting. This eliminates the need for an input relay, reducing costs. Furthermore, by filtering out high voltage, the charger will not stop working under high voltage conditions, allowing it to continue operating even when the mains voltage is too high, thus greatly improving ease of use.

[0046] In another embodiment of the invention, such asFigure 1 and Figure 3 As shown, the mains power input circuit 100 includes a positive mains power input terminal AC-N, a negative mains power input terminal AC-N, a common-mode inductor L3, and a fourth capacitor C4. The positive and negative mains power input terminals AC-N are used to connect to mains power. The first end of the common-mode inductor L3 is connected to both the positive and negative mains power input terminals AC-N, and the second end of the common-mode inductor L3 is connected to the fourth capacitor C4. The second end of the common-mode inductor L3 is also connected to the rectifier circuit 500. By using the common-mode inductor L3 and the fourth capacitor C4, the connected mains power is rectified and filtered, improving circuit safety performance.

[0047] In another embodiment of the invention, such as Figure 3 As shown, the PFC circuit 200 includes a first inductor L1, a first transistor Q1, and a first diode D1. The first terminal of the first inductor L1 is connected to the rectifier circuit 500. The drain of the first transistor Q1 is connected to the second terminal of the first inductor L1. The anode of the first diode D1 is connected to the second terminal of the first inductor L1. The cathode of the first diode D1 is connected to a high-voltage power supply terminal +385Vdc. The gate of the first transistor Q1 is used to connect to a PFC control circuit (not shown). The PFC control circuit can be designed by those skilled in the art, and this application does not impose specific limitations on it.

[0048] In another embodiment of the invention, such as Figures 1-3 As shown, the rectifier circuit 500 includes a second diode D2, a first thyristor V1, a second thyristor V2, and a third diode D3. The cathode of the second diode D2 is connected to the mains power input circuit 100. The anode of the first thyristor V1 is connected to the cathode of the second diode D2. The cathode of the second thyristor V2 is connected to the cathode of the first thyristor V1. The cathode of the third diode D3 is connected to the anode of the second thyristor V2. The cathode of the third diode D3 and the anode of the second thyristor V2 are also connected to the mains power input circuit. The anode of the third diode D3 is connected to the anode of the second diode D2. The anodes of the third diode D3 and the second diode D2 are also connected to the PFC circuit 200.

[0049] The control electrode of the first thyristor V1 and the control electrode of the second thyristor V2 are both connected to the main control chip U6.

[0050] Compared to the rectifier bridge in the prior art, the present invention achieves control over the rectification process by setting the first thyristor V1 and the second thyristor V2. Specifically, by setting the control electrode of the first thyristor V1 and the control electrode of the second thyristor V2 to be connected to the main control chip U6, the main control chip U6 can control the conduction angle of the first thyristor V1 and the second thyristor V2, thereby achieving rectification and filtering based on thyristors, so that the charger can still work when the mains voltage is too high.

[0051] Furthermore, the cathode of the second diode D2 is connected to the third pin of the common-mode inductor L3, and the first pin of the common-mode inductor L3 is connected to the cathode of the third diode D3 and the anode of the second thyristor V2. The cathode of the third diode D3 and the anode of the second thyristor V2 are also connected to the anode of the fourth diode D4, and after connection, to the +385Vdc high-voltage power supply terminal. The cathodes of the first thyristor V1 and the second thyristor V2 are also connected to the first inductor L1.

[0052] Furthermore, by setting the first thyristor V1 and the second thyristor V2, the EMI circuit is brought closer to the input end, cutting off the interference path from the inside of the machine to the input end. This eliminates the need for the magnetic ring wound on the input line, further improving the hardware circuit and reducing production costs.

[0053] In another embodiment of the invention, such as Figures 2-3 As shown, the input rectification protection circuit based on thyristors further includes a first thyristor driving circuit 410 and a second thyristor driving circuit 420. One end of the first thyristor driving circuit 410 is connected to the control electrode of the first thyristor V1, and the other end of the first thyristor driving circuit 410 is connected to the main control chip U6. One end of the second thyristor driving circuit 420 is connected to the control electrode of the second thyristor V2, and the other end of the second thyristor driving circuit 420 is connected to the main control chip U6.

[0054] In this embodiment, the main control chip U6 controls the first thyristor drive circuit 410 and the second thyristor drive circuit 420, thereby controlling the conduction angle of the first thyristor V1 and the second thyristor V2 through the first thyristor drive circuit 410 and the second thyristor drive circuit 420.

[0055] In another embodiment of the invention, such as Figure 3As shown, the first thyristor driving circuit 410 includes a first optocoupler, an eleventh transistor Q11, and a second resistor R2. The first pin of the first optocoupler is connected to the first power supply terminal +5V. The collector of the eleventh transistor Q11 is connected to the second pin of the first optocoupler. The base of the eleventh transistor Q11 is connected to the first pin of the main control chip U6. The fourth pin of the first optocoupler is connected to the second power supply terminal +12S. The second resistor R2 is connected to the third pin of the first optocoupler. The second resistor R2 is also connected to the control electrode of the first thyristor V1.

[0056] In this embodiment, the first optocoupler is divided into two parts in the schematic diagram, namely the input part U15A and the output part U15B. The first and second pins of the input part U15A are the first and second pins of the first optocoupler, and the third and fourth pins of the output part U15B are the third and fourth pins of the first optocoupler.

[0057] In another embodiment of the invention, such as Figure 3 As shown, the second thyristor driving circuit 420 includes a second optocoupler, a fifteenth transistor Q15, and a first resistor R1. The first pin of the second optocoupler is connected to the first power supply terminal +5V. The collector of the fifteenth transistor Q15 is connected to the second pin of the second optocoupler. The base of the fifteenth transistor Q15 is connected to the second pin of the main control chip U6. The fourth pin of the first optocoupler is connected to the second power supply terminal +12S. The first resistor R1 is connected to the third pin of the second optocoupler. The first resistor R1 is also connected to the control electrode of the second thyristor V2.

[0058] In this embodiment, the second optocoupler is divided into two parts in the schematic diagram, namely the input part U16A and the output part U16B. The first and second pins of the input part U16A are the first and second pins of the second optocoupler, and the third and fourth pins of the output part U16B are the third and fourth pins of the second optocoupler.

[0059] Specifically, the main control chip U6 sends signals to the first optocoupler and the second optocoupler, and controls the first thyristor V1 and the second thyristor V2 based on the first optocoupler and the second optocoupler respectively, thereby realizing the control of the conduction angle of the first thyristor V1 and the second thyristor V2.

[0060] In another embodiment of the invention, such as Figure 1 , Figure 2 and Figure 4As shown, the input detection circuit 300 includes a voltage detection circuit 310 and a phase detection circuit 320. The voltage detection circuit 310 is connected to the mains power input circuit 100, and the phase detection circuit 320 is connected to the voltage detection circuit 310. Both the voltage detection circuit 310 and the phase detection circuit 320 are connected to the main control chip U1. Phase and voltage detection are achieved respectively through the voltage detection circuit 310 and the phase detection circuit 320.

[0061] In another embodiment of the invention, such as Figure 4 As shown, the voltage detection circuit 310 includes a first operational amplifier U8B and a second operational amplifier U8A. The input terminals of the first operational amplifier U8B and the second operational amplifier U8A are connected to the mains power access circuit 100. The output terminal of the second operational amplifier U8A is connected to the output terminal of the first operational amplifier U8B. The output terminals of the first operational amplifier U8B and the second operational amplifier U8A are both connected to the fourteenth pin of the main control chip U6.

[0062] In another embodiment of the invention, such as Figure 4 As shown, the phase detection circuit 320 includes a fourteenth transistor Q14. The base of the fourteenth transistor Q14 is connected to the output terminal of the second operational amplifier U8A, and the emitter of the fourteenth transistor Q14 is connected to the nineteenth pin of the main control chip U6 and the first power supply terminal +5V.

[0063] In another embodiment of the invention, such as Figure 1 and Figure 5 As shown, the input rectification protection circuit based on thyristors also includes an auxiliary power supply circuit 600. The auxiliary power supply circuit 600 includes an auxiliary power management chip U4, a transformer T11, and an output management chip U5. The primary winding of the transformer T11 is connected to the high-voltage power supply terminal +385Vdc. The primary winding of the transformer T11 is also connected to the auxiliary power management chip U4. The output management chip U5 is connected to the secondary winding of the transformer T11, and outputs +5V through the auxiliary power supply terminal +5V after passing through the second pin of the output management chip U5.

[0064] In another embodiment of the invention, such as Figure 6 As shown, the present invention also provides a control method for an input rectifier protection circuit based on a silicon controlled rectifier (SCR), the method comprising the following steps:

[0065] Step S100: The input detection circuit 300 detects the input voltage of the mains power access circuit 100;

[0066] Step S200: The main control chip U6 acquires the input voltage detected by the input detection circuit 300, and determines whether the input voltage exceeds the preset normal voltage range based on the input voltage;

[0067] Step S300: If the determination is yes, the main control chip U6 controls the first thyristor V1 and the second thyristor V2 to conduct according to the preset thyristor conduction point when the input voltage drops to the preset normal voltage range, so that the rectifier circuit 500 filters out the voltage in the input voltage that exceeds the preset normal voltage range and outputs it.

[0068] The control method for the input rectification protection circuit based on thyristors described in this invention first detects the input voltage of the mains power access circuit 100 through the input detection circuit 300; then, the main control chip U6 acquires the input voltage detected by the input detection circuit 300 and determines whether the input voltage exceeds a preset normal voltage range; finally, if the determination is yes, the main control chip U6 controls the first thyristor V1 and the second thyristor V2 to conduct according to the preset thyristor conduction point when the input voltage drops to the preset normal voltage range, so that the rectifier circuit 500 filters out the voltage in the input voltage that exceeds the preset normal voltage range before outputting it. Thus, on the one hand, there is no need to set up an input relay, reducing costs; on the other hand, by filtering out high voltage, the charger will not directly stop working under high voltage conditions, so that the charger can still work when the mains voltage is too high, thereby greatly improving the convenience of use.

[0069] In another embodiment of the present invention, step S200: after the main control chip U6 acquires the input voltage detected by the input detection circuit 300 and determines whether the input voltage exceeds the preset normal voltage range based on the input voltage, it further includes:

[0070] If the determination is negative, the main control chip U6 controls the first thyristor V1 and the second thyristor V2 to conduct, so that the input voltage is output from the PFC circuit 200.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A thyristor-based input rectification protection circuit comprising a mains access circuit and a PFC circuit, characterized in that, Also include: Input detection circuit, the input detection circuit is connected with the mains access circuit, and is used for detecting the input voltage of the mains access circuit; The main control circuit includes a main control chip, the main control chip is connected with the input detection circuit, and is used for acquiring the input voltage detected by the input detection circuit; The rectifier circuit is connected with the mains access circuit and the main control chip, and the rectifier circuit is also connected with the PFC circuit, so that the main control chip sends an electrical signal to the rectifier circuit when the input voltage exceeds the preset normal voltage range, and the rectifier circuit includes two thyristors. When the input voltage exceeds the preset normal voltage range, the main control chip controls the first thyristor and the second thyristor to turn on according to the preset thyristor turn-on point when the input voltage drops to the preset normal voltage range, so that the rectifier circuit filters out the voltage exceeding the preset normal voltage range in the input voltage and outputs.

2. Thyristor-based input rectification protection circuit according to claim 1, characterized in that The rectifier circuit includes a second diode, a first thyristor, a second thyristor and a third diode, the cathode of the second diode is connected with the mains access circuit, the anode of the first thyristor is connected with the cathode of the second diode, the cathode of the second thyristor is connected with the cathode of the first thyristor, the cathode of the third diode is connected with the anode of the second thyristor, the cathode of the third diode and the anode of the second thyristor are also connected with the mains access circuit, the anode of the third diode is connected with the anode of the second diode, and the anode of the third diode and the anode of the second diode are also connected with the PFC circuit; The control electrode of the first thyristor and the control electrode of the second thyristor are connected with the main control chip.

3. Thyristor-based input rectification protection circuit according to claim 2, characterized in that It also includes a first thyristor drive circuit and a second thyristor drive circuit, one end of the first thyristor drive circuit is connected with the control electrode of the first thyristor, the other end of the first thyristor drive circuit is connected with the main control chip, one end of the second thyristor drive circuit is connected with the control electrode of the second thyristor, and the other end of the second thyristor drive circuit is connected with the main control chip.

4. Thyristor-based input rectification protection circuit according to claim 3, characterized in that The first thyristor drive circuit includes a first optocoupler, an eleventh transistor and a second resistor, the first pin of the first optocoupler is connected with a first power supply end, the collector of the eleventh transistor is connected with the second pin of the first optocoupler, the base of the eleventh transistor is connected with the first pin of the main control chip, the fourth pin of the first optocoupler is connected with a second power supply end, the second resistor is connected with the third pin of the first optocoupler, and the second resistor is also connected with the control electrode of the first thyristor.

5. The thyristor-based input rectification protection circuit of claim 3, wherein, The second silicon controlled rectifier driving circuit comprises a second optocoupler, a fifteenth transistor and a first resistor, a first pin of the second optocoupler is connected with the first power supply end, a collector of the fifteenth transistor is connected with a second pin of the second optocoupler, a base of the fifteenth transistor is connected with a second pin of the main control chip, a fourth pin of the second optocoupler is connected with the second power supply end, the first resistor is connected with a third pin of the second optocoupler, and the first resistor is also connected with a control electrode of the second silicon controlled rectifier.

6. Thyristor-based input rectification protection circuit according to any of claims 1-5, characterized in that, The input detection circuit comprises a voltage detection circuit and a phase detection circuit, the voltage detection circuit is connected with the commercial power access circuit, the phase detection circuit is connected with the voltage detection circuit, and the voltage detection circuit and the phase detection circuit are both connected with the main control chip.

7. Thyristor-based input rectification protection circuit according to claim 6, characterized in that The voltage detection circuit comprises a first operational amplifier and a second operational amplifier, input ends of the first operational amplifier and the second operational amplifier are connected with the commercial power access circuit, an output end of the second operational amplifier is connected with an output end of the first operational amplifier, and output ends of the first operational amplifier and the second operational amplifier are both connected with a fourteenth pin of the main control chip.

8. Thyristor-based input rectification protection circuit according to claim 7, characterized in that The phase detection circuit comprises a fourteenth transistor, a base of the fourteenth transistor is connected with an output end of the second operational amplifier, and an emitter of the fourteenth transistor is connected with a nineteenth pin of the main control chip and the first power supply end.

9. A method of controlling a thyristor-based input rectifier protection circuit according to any one of claims 1-8, characterized by, The method comprises the following steps: Step S100: The input detection circuit detects an input voltage of the commercial power access circuit. Step S200: The main control chip acquires the input voltage detected by the input detection circuit, and judges whether the input voltage exceeds a preset normal voltage range according to the input voltage. Step S300: If the judgment is yes, the main control chip controls the first silicon controlled rectifier and the second silicon controlled rectifier to be turned on according to a preset silicon controlled rectifier turn-on point when the input voltage drops to the preset normal voltage range, so that the rectification circuit outputs after filtering the voltage exceeding the preset normal voltage range in the input voltage.

10. The control method of the thyristor-based input rectification protection circuit according to claim 9, characterized in that, Step S200: After the main control chip acquires the input voltage detected by the input detection circuit and judges whether the input voltage exceeds a preset normal voltage range according to the input voltage, the method further comprises the following steps: If the judgment is no, the main control chip controls the first silicon controlled rectifier and the second silicon controlled rectifier to be turned on, so that the input voltage is output from the PFC circuit.

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