Control circuit of variable frequency air conditioner with low standby power consumption

Abstract

The invention provides a control circuit of a variable frequency air conditioner with low standby power consumption. The control circuit of the variable frequency air conditioner with low standby power consumption comprises a strong current power supply filter circuit, a PFC (Power Factor Correction) circuit, an inverter circuit and a switching power supply circuit, wherein the PFC circuit is arranged between the strong current power supply filter circuit and the inverter circuit, and the PFC circuit is used for supplying power to the inverter circuit; and the switching power supply circuit is used for supplying power to a weak current load. The strong and weak current loads are separately controlled, the technical problem that the standby power consumption of the variable-frequency mobile air conditioner is high, and the standby power consumption requirements of all regions cannot be met is solved, and the technical effect that the standby power consumption of the air conditioner is reduced to 0.5 W or below is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioners, and more specifically, to a control circuit for a variable-frequency air conditioner with low standby power consumption. Background Art

[0002] With the development of technology and the increasing improvement of people's living standards, air conditioners have become essential household appliances in people's lives. With the increasing maturity of technologies in the household appliance field and the increasingly fierce competition, consumers' requirements for the quality of air conditioners are also getting higher and higher.

[0003] Compared with fixed-frequency mobile air conditioners, variable-frequency mobile air conditioners have low noise and good comfort; and compared with split air conditioners, they are easy to install and move, and are gradually favored by the market. However, at present, the standby power consumption of variable-frequency mobile air conditioners on the market is generally high. Due to the relevant access regulations on low standby power consumption in some regions (e.g., Europe requires the standby power consumption to be less than 0.5W), variable-frequency mobile air conditioners are extremely rare in the market of these regions. Summary of the Invention

[0004] To solve the problem that the standby power consumption of variable-frequency mobile air conditioners is high and cannot meet the standby power consumption requirements of various regions, the present invention provides a control circuit for a variable-frequency air conditioner with low standby power consumption. The control circuit for the variable-frequency air conditioner with low standby power consumption includes: a strong power supply filtering circuit, a PFC circuit, an inverter circuit, and a switching power supply circuit; wherein, the PFC circuit is arranged between the strong power supply filtering circuit and the inverter circuit, and the PFC circuit is used to supply power to the inverter circuit; the switching power supply circuit is used to supply power to weak electrical loads.

[0005] Compared with the prior art, the technical effects achieved by adopting this technical solution are as follows: By setting a control circuit for a variable-frequency air conditioner with low standby power consumption including a strong power supply filtering circuit and a switching power supply circuit, and arranging a PFC circuit between the strong power supply filtering circuit and the inverter circuit, and separating the PFC circuit and the switching power supply circuit through a first rectifier circuit and a second rectifier circuit, the standby power consumption of the air conditioner can be reduced to less than 0.5W, meeting the standby power consumption requirements of various regions. The PFC circuit boosts the output voltage of the strong power supply filtering circuit for use by the subsequent inverter circuit (the intake fan motor in the room, the exhaust fan motor outdoors, and the compressor); the switching power supply circuit supplies power to weak electrical loads for use by weak electrical loads such as a display lamp board, 15V, and 12V.

[0006] In an example of the present invention, the control circuit for the variable-frequency air conditioner with low standby power consumption further includes: a first rectifier circuit arranged between the strong power supply filtering circuit and the PFC circuit; a second rectifier circuit arranged between the strong power supply filtering circuit and the switching power supply circuit.

[0007] Compared with the prior art, the technical effects achieved by adopting this technical solution are as follows: By arranging a first rectification circuit between the strong power supply filtering circuit and the PFC circuit, and arranging a second rectification circuit between the strong power supply filtering circuit and the switching power supply circuit, after the mains AC voltage is input, the PFC circuit and the switching power supply circuit can be separated through the first rectification circuit and the second rectification circuit.

[0008] In an example of the present invention, the strong power supply filtering circuit includes a first safety capacitor, and the second rectification circuit draws power from the strong power supply filtering circuit through the first safety capacitor.

[0009] Compared with the prior art, the technical effects achieved by adopting this technical solution are as follows: By arranging that the strong power supply filtering circuit includes a first safety capacitor, and arranging that the second rectification circuit draws power from the strong power supply filtering circuit through the first safety capacitor, the interference brought by the switching power supply can be effectively reduced.

[0010] In an example of the present invention, the control circuit of the variable-frequency air conditioner with low standby power consumption further includes: a first control circuit, arranged at the rear stage of the first safety capacitor; wherein, the first control circuit is controlled by the main control load power supply of 12V.

[0011] Compared with the prior art, the technical effects achieved by adopting this technical solution are as follows: By arranging a first control circuit at the rear stage of the first safety capacitor, and arranging that the first control circuit is controlled by the main control load power supply of 12V, when the air conditioner is in standby or shutdown, the first control circuit can be synchronously disconnected, thereby reducing the power consumption brought by the voltage detection circuit.

[0012] In an example of the present invention, the control circuit of the variable-frequency air conditioner with low standby power consumption further includes: a second safety capacitor, arranged between the neutral line and the live line of the strong power supply filtering circuit; a safety resistor, connected in parallel with the second safety capacitor.

[0013] Compared with the prior art, the technical effects achieved by adopting this technical solution are as follows: By arranging a second safety capacitor between the neutral line and the live line of the strong power supply filtering circuit, a power supply filtering effect can be achieved. By connecting a safety resistor in parallel at both ends of the second safety capacitor, it can prevent the power supply plug from being charged for a long time due to the charging and discharging process of the second safety capacitor when the power supply line is plugged or unplugged, meeting the safety standard requirements. In addition, by reducing the capacitance value of the second safety capacitor and increasing the resistance value of the safety resistor, the power consumption generated by the safety resistor during the standby of the air conditioner can be reduced.

[0014] In an example of the present invention, the switching power supply circuit outputs two paths of voltages. One path outputs an isolated power supply for the display lamp board only, and the other path outputs a main control load power supply of 15V-1 for the main control load to use.

[0015] In one embodiment of the present invention, the control circuit of the variable frequency air conditioner with low standby power consumption further includes: a second control circuit, which is arranged at the rear stage of the main control load power supply 15V-1.

[0016] Compared with the prior art, the technical effect achieved by adopting this technical solution is: by setting a second control circuit after the main control load power supply 15V-1, the display light board can be controlled by the second control circuit, so that the main control load power supply is cut off when the air conditioner is in standby or shut down. Among them, the second control circuit uses an optical coupler PC2 to isolate and control through the display light board.

[0017] In one embodiment of the present invention, the control circuit of the variable frequency air conditioner with low standby power consumption further includes: a dummy load resistor connected in parallel between the main control load power supply 15V-1 and the ground.

[0018] Compared with the prior art, the technical effect achieved by adopting this technical solution is: the larger the resistance of the dummy load resistor is, the smaller the power consumption caused by the air conditioner when it is in standby mode. Under the premise of satisfying the working conditions of the switching power supply, the power consumption generated by the air conditioner when it is in standby mode can be reduced by increasing the resistance of the dummy load resistor as much as possible.

[0019] In one example of the present invention, the control circuit of the variable frequency air conditioner with low standby power consumption further includes: a display light board MCU; wherein, when the air conditioner is on standby or turned off, the display light board MCU outputs a low level through the protection device BM1, and the first control circuit is disconnected.

[0020] In one example of the present invention, when the air conditioner is turned on, the display light board MCU outputs a high level through the protection device BM1, and the first control circuit is turned on.

[0021] After adopting the technical solution of the present invention, the following technical effects can be achieved:

[0022] (1) The control circuit of the variable frequency air conditioner with low standby power consumption includes a strong power supply filter circuit and a switching power supply circuit, and a PFC circuit is set between the strong power supply filter circuit and the inverter circuit. The PFC circuit and the switching power supply circuit can be separated through the first rectifier circuit and the second rectifier circuit, so that the standby power consumption of the air conditioner can be reduced to less than 0.5W, meeting the standby power consumption requirements of various regions. The output voltage of the strong power supply filter circuit is boosted by the PFC circuit for use by the subsequent inverter circuit (indoor air intake motor, outdoor exhaust motor and compressor); the weak current load is powered by the switching power supply circuit for use by the display light board, 15V, 12V and other weak current loads.

[0023] (2) By providing a first rectifying circuit between the strong power supply filtering circuit and the PFC circuit, and a second rectifying circuit between the strong power supply filtering circuit and the switching power supply circuit, after the mains AC voltage is input, the PFC circuit and the switching power supply circuit can be separated by the first rectifying circuit and the second rectifying circuit.

[0024] (3) By providing that the strong power supply filtering circuit includes a first safety capacitor, and setting that the first rectifying circuit draws power from the strong power supply filtering circuit through the first safety capacitor, the interference brought by the switching power supply can be effectively reduced. By providing a first control circuit at the rear stage of the first safety capacitor, and setting that the first control circuit is controlled by the main control load power supply of 12V, when the air conditioner is in standby or shutdown, the first control circuit can be synchronously disconnected, thereby reducing the power consumption brought by the voltage detection circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural diagram of a control circuit of a variable-frequency air conditioner with low standby power consumption provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following detailed description of specific embodiments of the present invention will be given with reference to the accompanying drawings.

[0027] Refer to Figure 1 , which is a schematic structural diagram of a control circuit of a variable-frequency air conditioner with low standby power consumption provided by the present invention. The control circuit of the variable-frequency air conditioner with low standby power consumption includes: a strong power supply filtering circuit, a PFC circuit, an inverter circuit, and a switching power supply circuit; wherein, the PFC circuit is provided between the strong power supply filtering circuit and the inverter circuit, and the PFC circuit is used to supply power to the inverter circuit; the switching power supply circuit is used to supply power to the weak electrical load. Among them, the control circuit of the variable-frequency air conditioner with low standby power consumption further includes a voltage detection circuit; the switching power supply circuit includes a display lamp board power supply circuit and a main control load power supply circuit.

[0028] It can be understood that by providing that the control circuit of the variable-frequency air conditioner with low standby power consumption includes a strong power supply filtering circuit and a switching power supply circuit, and providing a PFC circuit between the strong power supply filtering circuit and the inverter circuit, the PFC circuit and the switching power supply circuit can be separated by the first rectifying circuit and the second rectifying circuit, so that the standby power consumption of the air conditioner can be as low as below 0.5W, meeting the standby power consumption requirements of various regions. The PFC circuit boosts the output voltage of the strong power supply filtering circuit for use by the subsequent inverter circuit (the indoor intake fan, the outdoor exhaust fan, and the compressor); the switching power supply circuit supplies power to the weak electrical load for use by weak electrical loads such as the display lamp board, 15V, and 12V.

[0029] Further, the control circuit of the variable-frequency air conditioner with low standby power consumption further includes: a first rectifier circuit disposed between the strong power supply filtering circuit and the PFC circuit; a second rectifier circuit disposed between the strong power supply filtering circuit and the switching power supply circuit. For example, the first rectifier circuit is a rectifier bridge BG1; the second rectifier circuit is a rectifier bridge BG2.

[0030] It can be understood that by providing a first rectifier circuit between the strong power supply filtering circuit and the PFC circuit, and a second rectifier circuit between the strong power supply filtering circuit and the switching power supply circuit, after the mains AC voltage is input, the PFC circuit and the switching power supply circuit can be separated by the first rectifier circuit and the second rectifier circuit. Among them, the AC voltage can be extended and is applicable to different voltage types.

[0031] Further, the strong power supply filtering circuit includes a first safety capacitor, and the second rectifier circuit takes power from the strong power supply filtering circuit through the first safety capacitor. For example, the first safety capacitor is CRV5 and CRV6; the second rectifier circuit takes power from CRV5 and CRV6 of the strong power supply filtering circuit. Among them, CRV5 and CRV6 are Y capacitors.

[0032] It can be understood that by providing the strong power supply filtering circuit with a first safety capacitor, and setting the first rectifier circuit to take power from the strong power supply filtering circuit through the first safety capacitor, the interference brought by the switching power supply can be effectively reduced.

[0033] Further, the control circuit of the variable-frequency air conditioner with low standby power consumption further includes: a first control circuit disposed at the rear stage of the first safety capacitor; wherein, the first control circuit is controlled by the main control load power supply of 12V. For example, the first control circuit is disposed at the rear stage of CRV5 and CRV6, the voltage detection circuit is disposed at the rear stage of the first control circuit, and the first control circuit is a control circuit of relay RY1. When the air conditioner is in standby (shutdown), relay RY1 is disconnected, which can reduce the power consumption brought by the voltage detection circuit.

[0034] It can be understood that by providing a first control circuit at the rear stage of the first safety capacitor, and setting the first control circuit to be controlled by the main control load power supply of 12V, when the air conditioner is in standby or shutdown, the first control circuit can be synchronously disconnected, thereby reducing the power consumption brought by the voltage detection circuit.

[0035] Further, the control circuit of the variable-frequency air conditioner with low standby power consumption further includes: a second safety capacitor disposed between the neutral line and the live line of the strong power supply filtering circuit; a safety resistor connected in parallel with the second safety capacitor.

[0036] For example, the second safety capacitor is CRV1. Among them, CRV1 is an X capacitor, and safety resistors R1, R2, and R3 are connected in parallel across both ends of CRV1; R1, R2, and R3 are discharge resistors, and when the air conditioner is in standby, the discharge resistors R1, R2, and R3 will generate power consumption. An X capacitor CRV7 is provided at the rear stage of the first control circuit. At this time, the selection of the discharge resistor is only related to the X capacitor CRV1. In addition, by optimizing other EMC devices, the capacitance value of the X capacitor CRV1 can be reduced and the resistance values of R1, R2, and R3 can be increased, thereby further reducing the standby power consumption.

[0037] It can be understood that by setting a second safety capacitor between the neutral wire and the live wire of the strong power supply filtering circuit, the power supply filtering function can be achieved. By connecting a safety resistor in parallel across both ends of the second safety capacitor, it can prevent the power supply plug from being charged for a long time due to the charging and discharging process of the second safety capacitor when the power supply cord is plugged in or unplugged, meeting the requirements of the safety standard. In addition, by reducing the capacitance value of the second safety capacitor and increasing the resistance value of the safety resistor, the power consumption generated by the safety resistor when the air conditioner is in standby can be reduced.

[0038] Furthermore, the switching power supply circuit outputs two voltages. One outputs an isolated power supply for the display lamp board only, and the other outputs a main control load power supply of 15V-1 for the main control load.

[0039] Furthermore, the control circuit of the variable-frequency air conditioner with low standby power consumption further includes: a second control circuit, which is provided at the rear stage of the main control load power supply of 15V-1. Among them, the second control circuit uses an optocoupler PC2 to isolate and control through the display lamp board. In addition, the second control circuit is an isolated control and can be applied to the field of low-voltage isolation control.

[0040] It can be understood that by providing a second control circuit at the rear stage of the main control load power supply of 15V-1, the display lamp board can be controlled through the second control circuit, and the main control load power supply can be cut off when the air conditioner is in standby or shutdown.

[0041] Furthermore, the control circuit of the variable-frequency air conditioner with low standby power consumption further includes: a dummy load resistor, which is connected in parallel between the main control load power supply of 15V-1 and the ground.

[0042] It can be understood that the larger the resistance value of the dummy load resistor, the smaller the power consumption it brings when the air conditioner is in standby. On the premise of meeting the operation of the switching power supply, the power consumption generated when the air conditioner is in standby can be reduced by increasing the resistance value of the dummy load resistor as much as possible.

[0043] Furthermore, the control circuit of the variable-frequency air conditioner with low standby power consumption further includes: a display lamp board MCU; among them, when the air conditioner is in standby or shutdown, the display lamp board MCU outputs a low level through the protection device BM1, and the first control circuit is disconnected.

[0044] Furthermore, when the air conditioner is turned on, the display lamp board MCU outputs a high level through the protection device BM1, and the first control circuit is turned on.

[0045] In a specific embodiment, the main control MCU is connected to the strong power supply filtering circuit through PTC-1; the main control MCU is connected to the voltage detection circuit through AC-S and DC-S.

[0046] The specific control principle of the control circuit of the variable-frequency air conditioner with low standby power consumption is as follows: when the air conditioner is in standby (turned off), the display lamp board MCU outputs a low level through BM1, and the triodes Q1, optocoupler PC2, triode Q2, and PMOS transistor MOS1 are turned off, and there is no output of 15V, 12V, and 3.3V; since there is no 12V output, the first control circuit is disconnected. At this time, the power consumption of the air conditioner is mainly generated by the discharge resistor, switching power supply, and display lamp board. At the same time, by increasing the resistance values of the discharge resistors R1, R2, R3 and the dummy load R13, the standby power consumption can be made less than 0.5W.

[0047] When the air conditioner is turned on, the display lamp board MCU outputs a high level through BM1, the triodes Q1, optocoupler PC2, triode Q2, and PMOS transistor MOS1 are turned on, and 15V, 12V, and 3.3V are output. At the same time, the first control circuit is turned on.

[0048] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be determined by the scope defined by the claims.

Claims

1. The control circuit of a variable-frequency air conditioner with low standby power consumption, characterized in that, the control circuit of the variable-frequency air conditioner with low standby power consumption includes: a strong power supply filtering circuit, a PFC circuit, an inverter circuit, and a switching power supply circuit; wherein, the PFC circuit is arranged between the strong power supply filtering circuit and the inverter circuit, and the PFC circuit is used to supply power to the inverter circuit; the switching power supply circuit is used to supply power to the weak electrical load.

2. The control circuit of the variable-frequency air conditioner with low standby power consumption according to claim 1, characterized in that, the control circuit of the variable-frequency air conditioner with low standby power consumption further includes: a first rectification circuit, arranged between the strong power supply filtering circuit and the PFC circuit; a second rectification circuit, arranged between the strong power supply filtering circuit and the switching power supply circuit.

3. The control circuit of the variable-frequency air conditioner with low standby power consumption according to claim 2, characterized in that, the strong power supply filtering circuit includes a first safety capacitor, and the second rectification circuit takes power from the strong power supply filtering circuit through the first safety capacitor.

4. The control circuit of the variable-frequency air conditioner with low standby power consumption according to claim 3, characterized in that, the control circuit of the variable-frequency air conditioner with low standby power consumption further includes: a first control circuit, arranged at the rear stage of the first safety capacitor; wherein, the first control circuit is controlled by the main control load power supply of 12V.

5. The control circuit of the variable-frequency air conditioner with low standby power consumption according to claim 1, characterized in that, the control circuit of the variable-frequency air conditioner with low standby power consumption further includes: a second safety capacitor, arranged between the neutral wire and the live wire of the strong power supply filtering circuit; a safety resistor, connected in parallel with the second safety capacitor.

6. The control circuit of the variable-frequency air conditioner with low standby power consumption according to claim 1, characterized in that, the switching power supply circuit outputs two paths of voltages, one path outputs an isolated power supply for the display lamp board only, and the other path outputs a main control load power supply of 15V-1 for the main control load to use.

7. The control circuit of the variable-frequency air conditioner with low standby power consumption according to claim 6, characterized in that, the control circuit of the variable-frequency air conditioner with low standby power consumption further includes: a second control circuit, arranged at the rear stage of the main control load power supply of 15V-1.

8. The control circuit of the variable-frequency air conditioner with low standby power consumption according to claim 7, characterized in that, the control circuit of the variable-frequency air conditioner with low standby power consumption further includes: a dummy load resistor, connected in parallel between the main control load power supply of 15V-1 and the ground.

9. The control circuit of the variable-frequency air conditioner with low standby power consumption according to claim 4, characterized in that, the control circuit of the variable-frequency air conditioner with low standby power consumption further includes: a display lamp board MCU; wherein, when the air conditioner is in standby or shutdown, the display lamp board MCU outputs a low level through the protection device BM1, and the first control circuit is disconnected.

10. The control circuit of the variable-frequency air conditioner with low standby power consumption according to claim 9, characterized in that, when the air conditioner is turned on, the display lamp board MCU outputs a high level through the protection device BM1, and the first control circuit is turned on.

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