Circuit structure, air conditioning system and control method

Abstract

The invention provides a circuit structure, an air conditioning system and a control method, and the circuit structure comprises a bus circuit which is provided with a load; the voltage reduction assembly is connected with the bus circuit; the pressure reduction assembly comprises a control part; the control module is in signal connection with the control part, and the control module controls the bus circuit to be connected or disconnected through the control part; when the control part controls the bus circuit to be connected, the bus circuit charges the voltage reduction assembly; when the control part controls the bus circuit to be disconnected, the voltage reduction assembly supplies power to the bus circuit, and the circuit structure solves the technical problem that the voltage withstanding requirement of parts on the bus of the inverter circuit is high.

Description

Technical Field

[0001] The present invention relates to the field of circuit technology, and in particular to a circuit structure, an air conditioning system and a control method. Background Art

[0002] In the traditional variable frequency drive inverter circuit system, the high voltage bus is used to power the IPM module inverter, and the six IGBTs inside the IPM are alternately opened to control the AC motor to run, thereby realizing the operation of the entire motor drive system. The motor is an inductive load, and the variable frequency technology often has harmonic problems, which will have a negative impact on the power grid in the long run. Generally, some PFC circuits are also used to rectify the harmonic problem.

[0003] However, the high bus voltage power supply makes the selection of circuit components and IPM modules tend to be high-voltage type, which often makes the cost of the entire system high and the circuit complex. Therefore, the existing technology needs to be further developed. Summary of the invention

[0004] The purpose of the present invention is to overcome the above technical deficiencies and provide a circuit structure, an air conditioning system and a control method to solve the technical problem of high withstand voltage requirements of components on the busbar of the inverter circuit in the related art.

[0005] In order to achieve the above technical objectives, the present invention adopts the following technical solutions: a circuit structure is provided, including: a bus circuit, a load is arranged on the bus circuit; a step-down component, the step-down component is connected to the bus circuit; the step-down component includes a control component; a control module, the control module is signal-connected to the control component, and the control module controls the connection or disconnection of the bus circuit through the control component; when the control component controls the bus circuit to be connected, the bus circuit charges the step-down component; when the control component controls the bus circuit to be disconnected, the step-down component supplies power to the bus circuit.

[0006] Furthermore, the control component is an IGBT switch tube Q1 arranged on the bus circuit, and the gate of the IGBT switch tube Q1 is connected to the control module.

[0007] Furthermore, the step-down component includes an inductor L1, which is arranged on the bus circuit, one end of the inductor L1 is connected to the emitter of the IGBT switch tube Q1, and the other end of the inductor L1 is connected to the load.

[0008] Furthermore, the voltage-reducing component includes: a capacitor C1 connected in parallel with an inductor L1.

[0009] Furthermore, the bus circuit includes a P-phase circuit and an N-phase circuit; the step-down component includes a connecting circuit, one end of the connecting circuit is connected to the N-phase circuit, and the other end of the connecting circuit is connected to the circuit between the inductor L and the control component; the connecting circuit is provided with a diode D1; the diode D1 is connected in parallel with the capacitor C1.

[0010] Furthermore, the circuit structure includes a filter circuit, which includes: a first filter circuit, one end of the first filter circuit is connected to the P-phase circuit of the bus circuit; the other end of the first filter circuit is connected to the N-phase circuit of the bus circuit; a capacitor C2 is arranged on the first filter circuit; a second filter circuit, one end of the second filter circuit is connected to the P-phase circuit of the bus circuit; the other end of the second filter circuit is connected to the N-phase circuit of the bus circuit; a resistor is arranged on the second filter circuit; and the second filter circuit is connected to the first filter circuit.

[0011] Further, there are multiple first filter circuits, and the multiple first filter circuits are connected to each other; and / or there are multiple capacitors C2, and the multiple capacitors C2 are arranged at intervals on the first filter circuit.

[0012] Furthermore, the circuit structure includes a sampling circuit, the sampling circuit is connected to the bus circuit, a resistor R1 and a resistor R2 are provided on the sampling circuit, and the resistor R1 and the resistor R2 are connected in series; the control module is connected to the circuit signal between the resistor R1 and the resistor R2.

[0013] Furthermore, the circuit structure also includes a protection component, which includes: a relay K1 arranged on the bus circuit; the relay K1 is used to control the on and off of the bus circuit; an IGBT switch tube Q2, the IGBT switch tube Q2 is connected to the control module signal, and the control module controls the relay K1 to be closed or disconnected through the IGBT switch tube Q2.

[0014] Furthermore, the protection component includes: a protection circuit, one end of the protection circuit is connected to the control module, and the other end of the protection circuit is connected to the gate of the IGBT switch tube Q2; a resistor R4, which is arranged on the protection circuit; and a resistor R3, which is connected in parallel with the resistor R4.

[0015] Furthermore, there are multiple loads; and / or, the loads are connected to the control module, and the loads are driven by the control module.

[0016] An air conditioning system includes a circuit structure, and the circuit structure is the above-mentioned circuit structure.

[0017] Furthermore, the load of the circuit structure includes: a first drive module connected to the control module, the first drive module is used to drive the compressor; a second drive module connected to the control module, the first drive module is used to drive the fan.

[0018] A control method is applicable to the above-mentioned circuit structure, and the control method includes: a control module drives a control component to turn on the bus circuit; the control module drives the control component to close the bus circuit; repeating the above process to reduce the voltage of the bus circuit; and adjusting the voltage of the bus circuit by adjusting the frequency of turning on and off the control component.

[0019] Beneficial effects:

[0020] 1. The circuit structure of the present invention includes a bus circuit, on which a load is arranged; a step-down component, which is connected to the bus circuit; the step-down component includes a control component; a control module, which is connected to the control component by signal, and the control module controls the bus circuit to be connected or disconnected through the control component; when the control component controls the bus circuit to be connected, the bus circuit charges the step-down component; when the control component controls the bus circuit to be disconnected, the step-down component supplies power to the bus circuit. With the above arrangement, by shutting off the bus circuit, the low voltage of the step-down component temporarily replaces the high voltage of the bus circuit to supply power to the load, thereby achieving the effect of reducing the load pressure, improving harmonics and reducing the load withstand voltage, thereby reducing the selection of the withstand voltage of system components, thereby reducing the system cost, and solving the technical problem of high withstand voltage requirements of components on the bus of the inverter circuit.

[0021] 2. The circuit structure of the present invention proposes a drive circuit system that can adjust and reduce the bus voltage, which can improve harmonics and reduce system costs.

[0022] 3. The circuit structure of the present invention has bus voltage numerical display, fault display function and multiple shutdown protection circuits to ensure system safety and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic diagram of a circuit structure used in an embodiment of the present invention;

[0024] Figure 2 is a schematic diagram of the structure of a voltage-reducing component using a circuit structure according to an embodiment of the present invention;

[0025] Figure 3 It is a flow chart of the control method adopted in the embodiment of the present invention.

[0026] The above drawings include the following reference numerals:

[0027] 10. Bus circuit; 20. Step-down component; 21. Control component; 22. Connection circuit; 30. Control module; 31. First filter circuit; 32. Second filter circuit; 41. First drive module; 42. Compressor; 43. Second drive module; 44. Drive fan. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0029] See also Figures 1 to 3 According to an embodiment of the present invention, a circuit structure is provided, including: a bus circuit 10, on which a load is arranged; a step-down component 20, which is connected to the bus circuit 10; the step-down component 20 includes a control component 21; a control module 30, which is connected to the control component 21 by signal, and the control module 30 controls the bus circuit 10 to be connected or disconnected through the control component 21; when the control component 21 controls the bus circuit 10 to be connected, the bus circuit 10 charges the step-down component 20; when the control component 21 controls the bus circuit 10 to be disconnected, the step-down component 20 supplies power to the bus circuit 10. With the above arrangement, by shutting down the bus circuit 10, the low voltage of the step-down component 20 temporarily replaces the high voltage of the bus circuit 10 to supply power to the load, thereby achieving the effect of reducing the load pressure, improving harmonics and reducing the load withstand voltage, thereby reducing the selection of the withstand voltage of system components, thereby reducing the system cost, and solving the technical problem of high withstand voltage requirements of components on the bus of the inverter circuit.

[0030] See also Figure 1 , Figure 2 In the circuit structure of this embodiment, the control component 21 is an IGBT switch tube Q1 disposed on the bus circuit 10, and the gate of the IGBT switch tube Q1 is connected to the control module 30. In this way, the bus circuit 10 is controlled to be turned on and off by the GBT switch tube Q1, and the step-down component 20 is controlled to supply power to the load, thereby ensuring the normal operation of the circuit.

[0031] In the circuit structure of this embodiment, see Figure 1 , Figure 2 The step-down component 20 includes an inductor L1, which is arranged on the bus circuit 10. One end of the inductor L1 is connected to the emitter of the IGBT switch tube Q1, and the other end of the inductor L1 is connected to the load. L1 can achieve the function of energy storage, thereby supplying power to the load and reducing the voltage of the bus circuit 10.

[0032] In the circuit structure of this embodiment, see Figure 1 , Figure 2The step-down component 20 includes: a capacitor C1, which is connected in parallel with an inductor L1. In this way, Q1, L1, D1 and C1 can form a simple BUCK circuit. When Q1 is turned on, L1 and C1 are charged, and the current flows from P through Q1 and L1, flows through the load behind, and then returns from the N terminal to form a complete loop. When Q1 is disconnected, L1 has the ability to reduce current attenuation, and the voltage across C1 cannot change transiently. The potential of L1 is positive on the right and negative on the left, which is equivalent to discharging. Together with C1, it supplies power to the load end. The structure is simple and easy to implement.

[0033] See also Figure 1 , Figure 2 In the circuit structure of this embodiment, the bus circuit 10 includes a P-phase circuit and an N-phase circuit; the step-down component 20 includes a connecting circuit 22, one end of the connecting circuit 22 is connected to the N-phase circuit, and the other end of the connecting circuit 22 is connected to the circuit between the inductor L and the control component 21; the connecting circuit 22 is provided with a diode D1; the diode D1 is connected in parallel with the capacitor C1. In this way, it can be ensured that the current of the step-down component 20 flows to the load in the working direction, and the load is ensured to operate normally.

[0034] In the circuit structure of this embodiment, see Figure 1 The circuit structure includes a filter circuit, which includes: a first filter circuit 31, one end of the first filter circuit 31 is connected to the P phase circuit of the bus circuit 10; the other end of the first filter circuit 31 is connected to the N phase circuit of the bus circuit 10; the first filter circuit 31 is provided with a capacitor C2; a second filter circuit 32, one end of the second filter circuit 32 is connected to the P phase circuit of the bus circuit 10; the other end of the second filter circuit 32 is connected to the N phase circuit of the bus circuit 10; a resistor is provided on the second filter circuit 32; the second filter circuit 32 is connected to the first filter circuit 31. In this way, the bus circuit 10 can be filtered and a stable voltage can be provided for the subsequent load.

[0035] See also Figure 1 In the circuit structure of this embodiment, there are multiple first filter circuits 31, and the multiple first filter circuits 31 are connected to each other; and / or, there are multiple capacitors C2, and the multiple capacitors C2 are arranged on the first filter circuit 31 at intervals.

[0036] Specifically, C2 is 6 large-capacity electrolytic capacitors. The electrolytic capacitor C2 and two voltage-equalizing resistors form a busbar energy storage filter circuit, which can provide a stable voltage for the subsequent loads.

[0037] In the circuit structure of this embodiment, see Figure 1The circuit structure includes a sampling circuit, which is connected to the bus circuit 10. The sampling circuit is provided with a resistor R1 and a resistor R2, which are connected in series. The control module is connected to the circuit signal between the resistor R1 and the resistor R2. In this way, the resistor R1 and the resistor R2 form a sampling circuit of the bus circuit 10, and the sampling circuit is connected to the control module 30, so that the control module 30 controls the voltage of the bus circuit 10 according to the real-time voltage condition of the bus circuit 10.

[0038] See also Figure 1 In the circuit structure of this embodiment, the circuit structure also includes a protection component, which includes: a relay K1 arranged on the bus circuit 10; the relay K1 is used to control the on and off of the bus circuit 10; an IGBT switch tube Q2, the IGBT switch tube Q2 is connected to the control module 30 signal, and the control module 30 controls the relay K1 to be attracted or disconnected through the IGBT switch tube Q2. In this way, the protection component is controlled by the control module 30, and when the internal coil is energized, the gate can be pulled down to make P conductive, otherwise it is disconnected. Q2 is an IGBT switch tube, and the MCU 3 pin gives a signal to control the on and off of the internal coil of K1, thereby controlling the switch of K1. The normal operation of the circuit is guaranteed.

[0039] See also Figure 1 In the circuit structure of this embodiment, the protection component includes: a protection circuit, one end of the protection circuit is connected to the control module 30, and the other end of the protection circuit is connected to the gate of the IGBT switch tube Q2; a resistor R4 is arranged on the protection circuit; and a resistor R3 is connected in parallel with the resistor R4. In this way, R4 is a current limiting resistor and R3 is a turn-off resistor. K1, Q2, R3 and R4 can form a controllable bus protection circuit. When it is detected that the bus voltage is too low or too high or there is a strong fluctuation interference in the bus, a signal can be given through the control module 30, so that the circuit controls K1 to turn off the bus P, thereby protecting the safety of the rear load.

[0040] In the circuit structure of this embodiment, there are multiple loads; and / or the loads are connected to the control module 30, and the loads are driven by the control module 30. In this way, the performance of the circuit structure is improved.

[0041] The air conditioning system of this embodiment, see Figure 1 , including a circuit structure, the circuit structure is the above-mentioned circuit structure.

[0042] Specifically, the drive circuit system that reduces the bus voltage can improve harmonics and reduce load withstand voltage, thereby reducing the selection of system component withstand voltage and thus reducing system costs. The system is equipped with multiple shutdown protection circuits to improve system stability and safety and achieve safe and reliable operation of the drive circuit.

[0043] Specifically, the air conditioning system of this embodiment controls the control component 21 to turn on and off by modulating PWM, so that the voltage at both ends of the rear end bus of L1 is reduced to a preset voltage.

[0044] See also Figure 1 In the air-conditioning system of this embodiment, the load of the circuit structure includes: a first driving module 41, connected to the control module 30, and the first driving module 41 is used to drive the compressor 42; a second driving module 43, connected to the control module 30, and the first driving module 41 is used to drive the fan 44.

[0045] The control method of this embodiment is applicable to the above-mentioned circuit structure, and the control method includes: the control module 30 drives the control component 21 to turn on the bus circuit 10; the control module 30 drives the control component 21 to close the bus circuit 10; repeats the above process to reduce the voltage of the bus circuit 10; and adjusts the voltage of the bus circuit 10 by adjusting the frequency of turning on and off the control component 21.

[0046] The circuit structure of this embodiment is described as follows:

[0047] The drive circuit system of this embodiment that can adjust and reduce bus voltage can improve harmonics and reduce load withstand voltage, thereby reducing the selection of system component withstand voltage, thereby reducing system cost. The system is further equipped with multiple shutdown protection circuits to improve system stability and safety, and realize safe and reliable operation of the drive circuit.

[0048] like Figure 1 As shown, a dual-motor control system with a single compressor and a single fan sharing a busbar is taken as an example.

[0049] Q1 is an IGBT switch tube, L1 is an inductor, D1 is a diode, and C1 is an energy storage capacitor. Q1, L1, D1, and C1 can form a simple BUCK circuit. When Q1 is turned on, L1 and C1 are charged, and the current flows from P through Q1 and L1, flows through the load behind, and then returns from the N terminal to form a complete loop. When Q1 is disconnected, L1 has the ability to reduce current attenuation, and the voltage across C1 cannot change transiently. The potential of L1 is positive on the right and negative on the left, which is equivalent to discharge, and supplies power to the load end together with C1. Q1 is controlled by the modulated PWM square wave given by the MCU1 pin, and the switching process is repeated continuously to achieve voltage reduction. Its output voltage can be expressed as Vout = Vin*D, and the output voltage can be adjusted by adjusting the D (duty cycle) of PWM. At the same time, it can be used with a voltage sampling circuit as feedback to adjust D in real time to make the output voltage of the buck circuit stable. The specific amount of voltage reduction can also be achieved by adjusting D to achieve the function of adjustable voltage reduction.

[0050] Specifically, based on the principle of volt-second balance of inductance, that is, the voltage applied across the inductor multiplied by the conduction time is equal to the voltage across the inductor at the turn-off time multiplied by the turn-off time, (VOUT-VI N)*D=VOUT*(1-D), D=ton / ton+toff, Vout=Vi n*D, that is, by modulating the PWM of D to control the on and off of the device 21, the purpose of adjusting the bus voltage is achieved.

[0051] P and N are busbars, P is the positive terminal, and N is the negative terminal. R1 and R2 form a sampling circuit for busbar voltage, which enters through the 2-pin channel of the MCU, and the collected voltage can be displayed on the display module. C2 is a busbar energy storage filter circuit formed by 6 large-capacity electrolytic capacitors, electrolytic capacitor C2 and two voltage-equalizing resistors; it can provide a stable voltage for the subsequent loads. The two IPM modules control the compressor and fan motors respectively, and the PWM signals of their inverter circuits are controlled by the 4th and 5th pins of the MCU chip respectively.

[0052] K1 is a relay connected in parallel to the bus P. When the internal coil is energized, the gate can be pulled down to make P conductive, otherwise it is disconnected. Q2 is an IGBT switch tube. The MCU 3 pin gives a signal to control the power on and off of the internal coil of K1, thereby controlling the switch of K1. R4 is a current limiting resistor, and R3 is a turn-off resistor. K1, Q2, R3 and R4 can form a controllable bus protection circuit. When it is detected that the bus voltage is too low or too high or there is strong fluctuation interference in the bus, a signal can be given through the MCU 3 pin, so that the circuit controls K1 to turn off the bus P and disconnect it, thereby protecting the safety of the rear load. In addition, when the voltage is detected to be abnormal, the MCU can cut off all PWM signal outputs of pins 4, 5, and 1, so that Q1 is turned off and the two IPM modules are turned off, ensuring that all components stop working, realizing the function of multiple shutdown protection, and ensuring that the components are not damaged. At the same time, the MCU is equipped with 3 indicator lights on the periphery. When a fault occurs, the indicator lights can give an indication in the first time and display the fault code, so that relevant personnel can find the fault in the first time and deal with it in the first time.

[0053] The circuit structure of this embodiment can reduce the phase difference of the input voltage and current by adjusting the BUCK circuit, thereby reducing the power factor angle, thereby improving the harmonics of the entire circuit system and reducing the harmonic content.

[0054] The driving circuit system that reduces the bus voltage reduces the withstand voltage of the load components, thereby reducing the selection requirements for the withstand voltage of the system components and further reducing the system cost.

[0055] 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 in the protection scope of the present invention.

[0056] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0057] Optionally, the specific examples in this embodiment may refer to the examples described in the above embodiments, and this embodiment will not be described in detail here.

[0058] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0059] In the above embodiments of the present application, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0060] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A circuit structure, characterized in that: include: A bus circuit (10), wherein a load is arranged on the bus circuit (10); A step-down component (20), the step-down component (20) being connected to the bus circuit (10); the step-down component (20) comprising a control component (21); A control module (30), wherein the control module (30) is signal-connected to the control component (21), and the control module (30) controls the connection or disconnection of the bus circuit (10) through the control component (21); when the control component (21) controls the bus circuit (10) to be connected, the bus circuit (10) charges the step-down component (20); when the control component (21) controls the bus circuit (10) to be disconnected, the step-down component (20) supplies power to the bus circuit (10).

2. The circuit structure according to claim 1, characterized in that: The control component (21) is an IGBT switch tube Q1 arranged on the bus circuit (10), and the gate of the IGBT switch tube Q1 is connected to the control module (30).

3. The circuit structure according to claim 1, characterized in that: The step-down component (20) comprises an inductor L1, which is arranged on the bus circuit (10), one end of the inductor L1 is connected to the emitter of the IGBT switch tube Q1, and the other end of the inductor L1 is connected to the load.

4. The circuit structure according to claim 3, characterized in that: The pressure reducing component (20) comprises: The capacitor C1 is connected in parallel with the inductor L1.

5. The circuit structure according to claim 4, characterized in that: The bus circuit (10) includes a P-phase circuit and an N-phase circuit; the step-down component (20) includes a connecting circuit (22), one end of the connecting circuit (22) is connected to the N-phase circuit, and the other end of the connecting circuit (22) is connected to the circuit between the inductor L and the control component (21); the connecting circuit (22) is provided with a diode D1; the diode D1 is connected in parallel with the capacitor C1.

6. The circuit structure according to claim 1, characterized in that: The circuit structure includes a filter circuit, and the filter circuit includes: a first filter circuit (31), wherein one end of the first filter circuit (31) is connected to a P-phase circuit of the bus circuit (10); the other end of the first filter circuit (31) is connected to an N-phase circuit of the bus circuit (10); and a capacitor C2 is provided on the first filter circuit (31); A second filter circuit (32), one end of the second filter circuit (32) is connected to the P-phase circuit of the bus circuit (10); the other end of the second filter circuit (32) is connected to the N-phase circuit of the bus circuit (10); a resistor is provided on the second filter circuit (32); and the second filter circuit (32) is connected to the first filter circuit (31).

7. The circuit structure according to claim 6, characterized in that: There are multiple first filter circuits (31), and the multiple first filter circuits (31) are connected to each other; and / or, There are a plurality of capacitors C2, and the plurality of capacitors C2 are arranged at intervals on the first filter circuit (31).

8. The circuit structure according to claim 1, characterized in that: The circuit structure comprises a sampling circuit, the sampling circuit is connected to the bus circuit (10), a resistor R1 and a resistor R2 are arranged on the sampling circuit, the resistor R1 and the resistor R2 are connected in series; the control module is connected to the circuit signal between the resistor R1 and the resistor R2.

9. The circuit structure according to claim 1, characterized in that: The circuit structure further includes a protection component, and the protection component includes: A relay K1 is arranged on the bus circuit (10); the relay K1 is used to control the on and off of the bus circuit (10); IGBT switch tube Q2, the IGBT switch tube Q2 is signal-connected to the control module (30), and the control module (30) controls the relay K1 to be closed or disconnected through the IGBT switch tube Q2.

10. The circuit structure according to claim 9, characterized in that: The protection component comprises: A protection circuit, one end of the protection circuit being connected to the control module (30), and the other end of the protection circuit being connected to the gate of the IGBT switch tube Q2; A resistor R4 is provided on the protection circuit; The resistor R3 is connected in parallel with the resistor R4.

11. The circuit structure according to any one of claims 1 to 10, characterized in that: The load is multiple; and / or, The load is connected to the control module (30), and the load is driven by the control module (30).

12. An air conditioning system, comprising a circuit structure, characterized in that: The circuit structure is the circuit structure according to any one of claims 1 to 11.

13. The circuit structure according to claim 12, characterized in that: The load of the circuit structure includes: A first driving module (41) connected to the control module (30), wherein the first driving module (41) is used to drive a compressor (42); The second driving module (43) is connected to the control module (30), and the first driving module (41) is used to drive the fan (44).

14. A control method, applicable to the circuit structure according to any one of claims 1 to 11, characterized in that: The control method comprises: The control module (30) drives the control component (21) to conduct the bus circuit (10); The control module (30) drives the control component (21) to close the bus circuit (10); Repeating the above process to reduce the voltage of the bus circuit (10); By adjusting the frequency of turning on and off of the control component (21), the voltage of the bus circuit (10) is adjusted.

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