Circuit structure and air conditioning system

Abstract

The utility model provides a circuit structure and an air conditioning system, 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 resistance requirement of parts on the bus of the inverter circuit is high.

Description

Technical Field

[0001] The utility model relates to the technical field of circuits, in particular to a circuit structure and an air-conditioning system. Background Art

[0002] In traditional variable-frequency drive inverter circuit systems, a high-voltage busbar is used to power the IPM module. The six internal IGBTs (Inter-GBTs) are alternately activated to control the AC motor, thus enabling the entire motor drive system. However, as motors are inductive loads, variable-frequency technology often introduces harmonics, which can negatively impact the power grid over the long term. PFC circuits are typically used to address these harmonics.

[0003] However, the high bus voltage power supply forces the selection of circuit components and IPM modules to be high-voltage, which often increases the cost of the entire system and complicates the circuit. Therefore, the existing technology needs further development. Utility Model Content

[0004] The purpose of the present invention is to overcome the above technical deficiencies and provide a circuit structure and an air-conditioning system 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 provided 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 provided 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 provided 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 which is connected to the N-phase circuit, and the other end of which 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 provided 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 provided on the second filter circuit; and the second filter circuit is connected to the first filter circuit.

[0011] Furthermore, 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, which is connected to the bus circuit. The sampling circuit is provided with a resistor R1 and a resistor R2, which are connected in series; and 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 attracted 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, which 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] Beneficial effects:

[0019] 1. The circuit structure of the present invention includes a busbar circuit, on which a load is provided; a step-down component, which is connected to the busbar circuit; the step-down component includes a control component; a control module, which is connected to the control component by signal, and which controls the connection or disconnection of the busbar circuit through the control component; when the control component controls the busbar circuit to be connected, the busbar circuit charges the step-down component; when the control component controls the busbar circuit to be disconnected, the step-down component supplies power to the busbar circuit. With the above arrangement, by shutting off the busbar circuit, the low voltage of the step-down component temporarily replaces the high voltage of the busbar 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 system costs, and solving the technical problem of high withstand voltage requirements for components on the busbar of the inverter circuit.

[0020] 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.

[0021] 3. The circuit structure of this utility model has bus voltage numerical display, fault display function and multiple shutdown protection circuits to ensure system safety and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural diagram of the circuit structure adopted in the embodiment of the present utility model;

[0023] Figure 2 This is a schematic structural diagram of a step-down component of a circuit structure used in an embodiment of the present utility model;

[0024] Figure 3 It is a schematic diagram of the working process of the circuit structure adopted in the embodiment of the present utility model.

[0025] The above drawings include the following reference numerals:

[0026] 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

[0027] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0028] See also Figures 1 to 3 According to an embodiment of the present invention, a circuit structure is provided, comprising: a bus circuit 10, on which a load is disposed; a step-down assembly 20, connected to the bus circuit 10; the step-down assembly 20 including a control component 21; and a control module 30, signal-connected to the control component 21. 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 assembly 20; when the control component 21 controls the bus circuit 10 to be disconnected, the step-down assembly 20 supplies power to the bus circuit 10. With this arrangement, by shutting off the bus circuit 10, the low voltage of the step-down assembly 20 temporarily replaces the high voltage of the bus circuit 10 to supply power to the load, thereby reducing load pressure, improving harmonics, and lowering load withstand voltage, thereby reducing the selection of system component withstand voltages, thereby reducing system costs, and resolving the technical problem of high withstand voltage requirements for components on the bus of the inverter circuit.

[0029] Specifically, the air conditioning system of this embodiment performs on-off control by modulating the PWM control component 21, so that the voltage at both ends of the rear-end bus of L1 is reduced to a preset voltage.

[0030] See also Figure 1 、 Figure 2 In the circuit structure of this embodiment, the control component 21 is an IGBT switch Q1 provided on the bus circuit 10. The gate of the IGBT switch Q1 is connected to the control module 30. In this way, the IGBT switch Q1 controls the conduction and disconnection of the bus circuit 10 and controls the step-down component 20 to supply power to the load, ensuring normal circuit operation.

[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 connected in parallel with an inductor L1. Thus, Q1, L1, D1, and C1 form a simple buck circuit. When Q1 is on, L1 and C1 are charged, and current flows from P through Q1 and L1, flows through the load, and returns from the N terminal to form a complete loop. When Q1 is off, 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 busbar 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 which is connected to the N-phase circuit, and the other end of which is connected to the circuit between the inductor L and the control component 21. The connecting circuit 22 is provided with a diode D1, which is connected in parallel with the capacitor C1. This ensures that the current of the step-down component 20 flows to the load in the working direction, ensuring normal operation of the load.

[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 which is connected to the P-phase circuit of the bus circuit 10; the other end of which is connected to the N-phase circuit of the bus circuit 10; a capacitor C2 disposed on the first filter circuit 31; a second filter circuit 32, one end of which is connected to the P-phase circuit of the bus circuit 10; the other end of which is connected to the N-phase circuit of the bus circuit 10; a resistor disposed on the second filter circuit 32; and 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 to subsequent loads.

[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 at intervals on the first filter circuit 31.

[0036] Specifically, C2 is a busbar energy storage and filtering circuit formed by six large-capacity electrolytic capacitors. The electrolytic capacitors C2 and two equalizing resistors 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 connected to the bus circuit 10. The sampling circuit is provided with resistors R1 and R2, which are connected in series. A control module is connected to the circuit signal between resistors R1 and R2. Thus, resistors R1 and R2 form the sampling circuit of the bus circuit 10. The sampling circuit is connected to the control module 30, so that the control module 30 controls the voltage of the bus circuit 10 based on the real-time voltage of the bus circuit 10.

[0038] See also Figure 1 In this embodiment, the circuit structure also includes a protection component, which includes: a relay K1 disposed on the bus circuit 10; relay K1 is used to control the on / off state of the bus circuit 10; and an IGBT switch Q2. The IGBT switch Q2 is signal-connected to the control module 30, and the control module 30 controls the closing or opening of relay K1 through the IGBT switch Q2. Thus, the protection component is controlled by the control module 30. When the internal coil is energized, the gate is pulled down, turning P on; otherwise, it is turned off. Q2 is an IGBT switch, and the MCU sends a signal from pin 3 to control the opening and closing of the internal coil of K1, thereby controlling the on / off state of K1. This ensures normal circuit operation.

[0039] See also Figure 1 In the circuit structure of this embodiment, the protection component includes: a protection circuit, one end of which is connected to the control module 30, and the other end of which is connected to the gate of the IGBT switch tube Q2; a resistor R4, which is provided on the protection circuit; and a resistor R3, which is connected in parallel with the resistor R4. In this way, R4 is a current-limiting resistor and R3 is a shutdown 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 on the bus, a signal can be sent through the control module 30, causing the circuit to control K1 to shut down the bus P, thereby protecting the safety of the downstream 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, a drive circuit system that reduces bus voltage can improve harmonics and lower load withstand voltage, thereby reducing the selection of system component withstand voltages and thus reducing system costs. The system is also equipped with multiple shutdown protection circuits to improve system stability and safety, ensuring safe and reliable operation of the drive circuit.

[0043] See also Figure 1In 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.

[0044] The circuit structure of this embodiment is described as follows:

[0045] This embodiment of a drive circuit system with adjustable bus voltage reduction can improve harmonics and reduce load withstand voltage, thereby reducing the selection of system component withstand voltages and thus reducing system costs. The system is also equipped with multiple shutdown protection circuits to improve system stability and safety, ensuring safe and reliable operation of the drive circuit.

[0046] like Figure 1 As shown, a dual-motor control system with a single compressor and a single fan sharing a busbar is used as an example.

[0047] Q1 is an IGBT switch, L1 is an inductor, D1 is a diode, and C1 is an energy storage capacitor. Q1, L1, D1, and C1 form a simple buck circuit. When Q1 is on, L1 and C1 charge. Current flows from P through Q1 and L1, then flows through the load and returns to N, completing the circuit. When Q1 is off, L1 reduces current decay, preventing transient voltage changes across C1. L1's potential becomes positive on the right and negative on the left, effectively discharging, and together with C1, supplies power to the load. Q1 is controlled by a modulated PWM square wave supplied by MCU pin 1, repeatedly switching on and off to achieve voltage reduction. Its output voltage is expressed as Vout = Vin * D. The output voltage is adjusted by adjusting the PWM duty cycle (D). A voltage sampling circuit can also be used as feedback to adjust D in real time, ensuring stable output voltage. The desired voltage reduction can also be achieved by adjusting D, creating an adjustable step-down function.

[0048] Specifically, based on the principle of volt-second balance of the inductor, 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 control of D to control the on and off of the 21 devices, the purpose of adjusting the bus voltage is achieved.

[0049] P and N represent the busbars, with P being the positive terminal and N being the negative terminal. R1 and R2 form the busbar voltage sampling circuit, which inputs the voltage through pin 2 of the MCU. The collected voltage is displayed on the display module. C2 represents six large-capacity electrolytic capacitors. Electrolytic capacitors C2 and two equalizing resistors form a busbar energy storage and filtering circuit, providing a stable voltage for subsequent loads. Two IPM modules control the compressor and fan motors, respectively. The PWM signals of their inverter circuits are controlled by pins 4 and 5 of the MCU chip, respectively.

[0050] K1 is a relay connected in parallel to bus P. When the internal coil is energized, it pulls down the brake disc, turning P on and off; otherwise, it turns it off. Q2 is an IGBT switch. A signal from MCU pin 3 controls the on / off of K1's internal coil, thereby controlling K1's switching. R4 is a current-limiting resistor, and R3 is a shutdown resistor. K1, Q2, R3, and R4 form a controllable bus protection circuit. When the bus voltage is detected to be too low or too high, or when there is strong bus interference, a signal from MCU pin 3 controls K1 to disconnect bus P, thereby protecting downstream loads. Furthermore, when voltage abnormalities are detected, the MCU disconnects all PWM signals from pins 4, 5, and 1, shutting down Q1 and both IPM modules. This ensures that all components cease operation, implementing multiple shutdown protections to prevent component damage. The MCU is also equipped with three indicator lights that immediately indicate a fault and display a fault code, allowing personnel to quickly identify and address the problem.

[0051] The circuit structure of this embodiment can reduce the phase difference of the input voltage and current by adjusting the BUCK circuit, thereby lowering the power coefficient angle, thereby improving the harmonics of the entire circuit system and reducing the harmonic content.

[0052] 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.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0054] 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 sequential order. 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 a sequence 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.

[0055] 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.

[0056] 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.

[0057] In the above embodiments of the present application, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0058] The above is only a preferred embodiment 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 provided 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) is connected to the control component (21) by signal, 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, wherein: The control component (21) is an IGBT switch tube Q1 provided 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 2, wherein: 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, wherein: The pressure reduction component (20) includes: The capacitor C1 is connected in parallel with the inductor L1.

5. The circuit structure according to claim 4, characterized in that: The busbar 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, wherein: The circuit structure includes a filter circuit, and the filter circuit includes: a first filter circuit (31), one end of the first filter circuit (31) being connected to the P-phase circuit of the bus circuit (10); the other end of the first filter circuit (31) being connected to the N-phase circuit of the bus circuit (10); and a capacitor C2 being 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 multiple capacitors C2, and the multiple capacitors C2 are arranged at intervals on the first filter circuit (31).

8. The circuit structure according to claim 1, wherein: 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 provided 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, wherein: The circuit structure further includes a protection component, which includes: A relay K1 is provided 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 via the IGBT switch tube Q2.

10. The circuit structure according to claim 9, characterized in that: The protection component includes: 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; Resistor R4, 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: There are multiple loads; 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 air conditioning system according to claim 12, characterized in that The load of the circuit structure includes: A first driving module (41) is connected to the control module (30), and the first driving module (41) is used to drive a compressor (42); The second drive module (43) is connected to the control module (30), and the first drive module (41) is used to drive the fan (44).

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