Air conditioner outdoor unit standby power supply circuit and control method thereof

Abstract

The invention discloses a standby power supply circuit of an air conditioner outdoor unit and a control method of the standby power supply circuit. The power supply circuit comprises a driving circuit, a relay control circuit, a control unit and a switching power supply circuit. The driving circuit is used for driving the power device; the relay control circuit is used for controlling the working state of the power device, and the working state comprises a standby state and a normal working state; the control unit is used for controlling on-off of a corresponding relay in the relay control circuit. And the switching power supply circuit is used for supplying power to the relay control circuit and the control unit. The probability of electric corrosion and electric breakdown between a high-power device and a radiator as well as between the high-power device and a power device pin in a refrigerant heat dissipation system independently powered by an outdoor unit can be reduced, and the purposes of reducing electric corrosion and electric breakdown risks caused by condensate water and improving the stability and safety of the system are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of power supply systems for air-conditioning outdoor units, and in particular relates to a standby power supply circuit for an air-conditioning outdoor unit and a control method thereof. Background Art

[0002] In the existing refrigerant cooling system with independent power supply for outdoor units, the radiator is connected to the system pipeline and has a large contact area with the air, which is easily affected by moisture and produces condensed water. At the same time, the radiator is connected to high-power devices. This condensed water may cause electrical corrosion and electrical breakdown between the high-power devices and the radiator, as well as between the pins of the power devices, affecting the stability and safety of the system. Summary of the invention

[0003] In order to solve the above problems, the present invention provides a standby power supply circuit for an air-conditioning outdoor unit and a control method thereof, which can reduce the probability of electrical corrosion and electrical breakdown between high-power devices and the radiator, and between the pins of power devices in the refrigerant heat dissipation system in which the outdoor unit is independently powered, thereby reducing the risk of electrical corrosion and electrical breakdown caused by condensed water and improving the stability and safety of the system.

[0004] The technical solution adopted by the present invention is:

[0005] In a first aspect, the present application discloses a standby power supply circuit for an air conditioner outdoor unit, comprising a drive circuit, a relay control circuit, a control unit, and a switch power supply circuit. The drive circuit is used to drive a power device;

[0006] The output end of the relay control circuit is connected to the input end of the drive circuit, and is used to control the working state of the power device, and the working state includes a standby state and a normal working state; the signal output end of the control unit is connected to the corresponding signal input end of the relay control circuit, and is used to control the on and off of the corresponding relay in the relay control circuit; the switching power supply circuit is used to provide power for the relay control circuit and the control unit.

[0007] As an optional technical solution, the drive circuit includes a first single-phase bridge rectifier DB2 and a power device connected to the output end of the first single-phase bridge rectifier, the power device includes a power diode, an IGBT and an IPM module; the input end of the first single-phase bridge rectifier constitutes the input end of the entire drive circuit, and a bus capacitor C2 is connected between the power diode and the IGBT.

[0008] As an optional technical solution, the relay control circuit includes a first relay K401, a second relay K402, a third relay K403, diodes VD1, VD2, VD3 and a current-limiting resistor R401; the contact circuit of the first relay K401 is connected in series with the current-limiting resistor R401 and then connected to the live wire, and the coil of the first relay K401 is connected in parallel with the diode VD1, one end of which is connected to the first signal input terminal, and the other end is connected to the 12V power supply; the contact circuit of the second relay K402 is connected to the neutral line, and the coil of the second relay K402 is connected in parallel with the diode VD2, one end of which is connected to the second signal input terminal, and the other end is connected to the 12V power supply; the contact circuit of the third relay K403 is used to short-circuit the current-limiting resistor R401 and the first relay K401 in the normal working state, and the coil of the third relay K403 is connected in parallel with the diode VD3, one end of which is connected to the third signal input terminal, and the other end is connected to the 12V power supply.

[0009] As an optional technical solution, the first signal output terminal, the second signal output terminal and the third signal output terminal of the control unit are respectively connected to the first signal input terminal, the second signal input terminal and the third signal input terminal of the relay control circuit, and are used to control the working states of the first relay K401, the second relay K402 and the third relay K403; when in the standby state, the control unit controls the first relay K401, the second relay K402 and the third relay K403 to be in the disconnected state, so that the drive circuit remains in the power-off state; when in the normal working state, the control unit controls the moving and static contacts of the third relay K403 to be connected and conducted, the moving and static contacts of the second relay K402 to be connected and conducted, and the moving and static contacts of the first relay K401 to be disconnected.

[0010] As an optional technical solution, the switching power supply circuit includes a second single-phase bridge rectifier DB1, a filter capacitor C1 and a switching power supply; the input port of the second single-phase bridge rectifier is connected to the mains, and the output port is connected to the input port of the switching power supply; the filter capacitor C1 is connected between the output ports of the second single-phase bridge rectifier; the switching power supply has three-level output, namely 5V, 12V, and 15V output, wherein the 5V output is used to supply the control unit, the 12V output is used to supply the relay control circuit, and the 15V output is used to supply the drive circuit.

[0011] As an optional technical solution, the switching power supply includes: an isolation transformer T1, a switch IC D1, diodes VD5-VD7, capacitors C4-C6, and transformer secondary output power supplies of 15V, 12V, and 5V; wherein the diode VD5 and the capacitor C4 are connected to the first group of secondary outputs of the transformer to output a 15V power supply; the diode VD6 and the capacitor C5 are connected to the second group of secondary outputs of the transformer to output a 12V power supply; the diode VD7 and the capacitor C6 are connected to the third group of secondary outputs of the transformer to output a 5V power supply; the 15V, 12V, and 5V power supplies are shared by a common ground, and are shared by a common ground with the drive circuit and the control unit; the reference ground of the transformer primary switch IC D1 is connected to the negative output of the second single-phase bridge rectifier and is isolated from the secondary ground by an isolation transformer.

[0012] In a second aspect, the present application discloses a control method for a power supply circuit, wherein the power supply circuit includes the standby power supply circuit of the air conditioner outdoor unit as described in the first aspect above, and the method includes:

[0013] When the control unit does not receive the power-on signal, the control unit outputs the first control signal, the second control signal, and the third control signal to the first relay K401, the second relay K402, and the third relay K403 respectively, so as to control the moving and static contacts of the first relay K401, the second relay K402, and the third relay K403 to remain in the disconnected state, so that the connection between the drive circuit and the live wire L and the neutral wire N is disconnected, and the drive circuit remains in the power-off state and enters the standby state.

[0014] When the control unit receives the power-on signal, the control unit first controls the moving and static contacts of the first relay K401 and the second relay K402 to be connected and conducted. At this time, the bus capacitor C2 in the drive circuit is charged through the current limiting resistor R401; after the charging delay is a predetermined time, the control unit sends a fourth control signal to control the moving and static contacts of the third relay K403 to be connected and conducted, so as to short-circuit the first relay K401 and the current limiting resistor R401; then the control unit sends a fifth control signal to control the moving and static contacts of the first relay K401 to be disconnected and enter a normal working state.

[0015] As an optional technical solution, the method also includes: in normal working state, when the control unit receives a shutdown signal, the control unit outputs a control signal to disconnect the connection between the moving and static contacts of the second relay K402 and the third relay K403, so that the drive circuit is in a power-off state and enters the standby state again.

[0016] The beneficial effects of the present invention are as follows: in the present application, by disconnecting the connection between the drive circuit and the live wire L and the neutral wire N in standby mode, the power device in the drive circuit and the refrigerant radiator have no potential difference. The probability of electrical corrosion and electrical breakdown between high-power devices and the radiator and power device pins caused by condensed water in the refrigerant cooling system with a separate power supply for the outdoor unit can be effectively reduced, thereby improving the reliability and safety of the electric control. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a circuit block diagram of a standby power supply circuit of an air conditioner outdoor unit in an exemplary embodiment.

[0018] Figure 2 is a circuit schematic diagram of a driving circuit in an exemplary embodiment.

[0019] Figure 3 is a circuit schematic diagram of a relay control circuit in an exemplary embodiment.

[0020] Figure 4 is a circuit schematic diagram of a control unit in an exemplary embodiment.

[0021] Figure 5 is a circuit schematic diagram of a switching power supply circuit in an exemplary embodiment.

[0022] Figure 6 is a further circuit schematic diagram of a switching power supply circuit in an exemplary embodiment. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. The components and method steps of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0024] Example

[0025] like Figure 1As shown, this embodiment discloses a standby power supply circuit for an air conditioner outdoor unit, including a drive circuit 1, a relay control circuit 2, a control unit 3 and a switch power supply circuit 4. The drive circuit 1 is used to drive a power device; the output end of the relay control circuit 2 is connected to the input end of the drive circuit 1, and is used to control the working state of the power device, and the working state includes a standby state and a normal working state; the signal output end of the control unit 3 is connected to the corresponding signal input end of the relay control circuit 2, and is used to control the on and off of the corresponding relay in the relay control circuit 2, thereby controlling the conduction or disconnection of the drive circuit 1 and the mains (live wire L, neutral wire N), so as to achieve the purpose of controlling the working state of the drive circuit 1; the switch power supply circuit 4 is used to provide power for the relay control circuit 2 and the control unit 3.

[0026] As an optional implementation, Figure 2 As shown, the drive circuit 1 includes a first single-phase bridge rectifier DB2 and a power device connected to the output end of the first single-phase bridge rectifier, and the power device includes a power diode (VD8-VDN), an IGBT (D5-DN) and an IPM module; the input end of the first single-phase bridge rectifier constitutes the input end of the entire drive circuit, and the input end is connected to the output end of the relay control circuit 2, as shown in FIG. Figure 2 and Figure 3 As shown, the L1 ends in the two figures are connected together and the N1 ends are connected together. A bus capacitor C2 is connected between the power diode and the IGBT. The drive circuit 1 adopts the existing technology. The purpose of this embodiment is to control the on-off of each existing power device in the drive circuit 1 and the mains (live wire L, neutral wire N) through the relay control circuit 2, so that when in standby mode, the power diode (VD8-VDN), IGBT (D5-DN) and IPM module are disconnected from the live wire L and the neutral wire N, so that there is no potential difference between each power device and the refrigerant radiator, so as to reduce the probability of electrical corrosion and electrical breakdown between high-power devices and radiators and power device pins caused by condensed water, and improve the reliability and safety of electronic control.

[0027] As an optional implementation, Figure 3As shown, the relay control circuit 2 includes a first relay K401, a second relay K402, a third relay K403, diodes VD1, VD2, VD3 and a current limiting resistor R401; the contact loop of the first relay K401 is connected in series with the current limiting resistor R401 and then connected to the live wire, and the coil of the first relay K401 is connected in parallel with the diode VD1, one end of which is connected to the first signal input terminal, and the other end is connected to the 12V power supply; the contact loop of the second relay K402 is connected to the neutral line, and the coil of the second relay K402 is connected in parallel with the diode VD2, one end of which is connected to the second signal input terminal, and the other end is connected to the 12V power supply; the contact loop of the third relay K403 is used to short-circuit the current limiting resistor R401 and the first relay K401 in the normal working state, and the coil of the third relay K403 is connected in parallel with the diode VD3, one end of which is connected to the third signal input terminal, and the other end is connected to the 12V power supply.

[0028] As an optional implementation, Figure 4 As shown, the first signal output terminal, the second signal output terminal and the third signal output terminal of the control unit 3 are respectively connected to the first signal input terminal, the second signal input terminal and the third signal input terminal of the relay control circuit 2, and are used to control the working state of the first relay K401, the second relay K402 and the third relay K403; when in the standby state, the control unit 3 controls the first relay K401, the second relay K402 and the third relay K403 to be disconnected, so that the drive circuit 1 remains in a power-off state (i.e., disconnected from the live wire L and the neutral wire N); when in the normal working state, the control unit 3 controls the moving and static contacts of the third relay K403 to be connected and conducted, the moving and static contacts of the second relay K402 to be connected and conducted, and the moving and static contacts of the first relay K401 to be disconnected. In this embodiment, the control unit 3 can be used but not limited to a single-chip microcomputer of the Renesas R5F526T model.

[0029] As an optional implementation, Figure 5 As shown, the switching power supply circuit 4 includes a second single-phase bridge rectifier DB1, a filter capacitor C1 and a switching power supply; the input port of the second single-phase bridge rectifier is connected to the mains, and the output port is connected to the input port of the switching power supply; the filter capacitor C1 is connected between the output ports of the second single-phase bridge rectifier; the switching power supply has three-level output, namely 5V, 12V, and 15V output, wherein the 5V output is used to supply the control unit, the 12V output is used to supply the relay control circuit, and the 15V output is used to supply the drive circuit.

[0030] As an optional implementation, Figure 6As shown, the switching power supply includes: an isolation transformer T1, a switch ICD1, diodes VD5-VD7, capacitors C4-C6, and transformer secondary output power supplies 15V, 12V, and 5V; wherein the diode VD5 and the capacitor C4 are connected to the first group of secondary outputs of the transformer to output a 15V power supply; the diode VD6 and the capacitor C5 are connected to the second group of secondary outputs of the transformer to output a 12V power supply; the diode VD7 and the capacitor C6 are connected to the third group of secondary outputs of the transformer to output a 5V power supply; the 15V, 12V, and 5V power supplies are grounded in common, and are grounded in common with the drive circuit and the control unit; the reference ground of the transformer primary switch IC D1 is connected to the negative end output of the second single-phase bridge rectifier bridge, and is isolated from the secondary ground by the isolation transformer. This embodiment also discloses a control method for a power supply circuit, and the power supply circuit includes a standby power supply circuit for an air conditioner outdoor unit as in the above embodiment, and the method includes:

[0031] When the control unit 3 does not receive the power-on signal, the control unit 3 outputs the first control signal, the second control signal, and the third control signal to the first relay K401, the second relay K402, and the third relay K403 respectively, so as to control the moving and static contacts of the first relay K401, the second relay K402, and the third relay K403 to remain in the disconnected state, so that the connection between the drive circuit 1 and the live wire L and the neutral wire N is disconnected, and the drive circuit 1 remains in the power-off state and enters the standby state.

[0032] When the control unit 3 receives the power-on signal, the control unit 3 first controls the moving and static contacts of the first relay K401 and the second relay K402 to be connected and conducted. At this time, the bus capacitor C2 in the drive circuit is charged through the current limiting resistor R401; after the charging delay is a predetermined time, the control unit 3 sends a fourth control signal to control the moving and static contacts of the third relay K403 to be connected and conducted, so as to short-circuit the first relay K401 and the current limiting resistor R401; then the control unit 3 sends a fifth control signal to control the moving and static contacts of the first relay K401 to be disconnected and enter a normal working state.

[0033] As an optional implementation, the method also includes: in normal working state, when the control unit 3 receives a shutdown signal, the control unit 3 outputs a control signal to disconnect the connection between the moving and static contacts of the second relay K402 and the third relay K403, so that the drive circuit 1 is in a power-off state and enters the standby state again.

[0034] In order to better understand this embodiment, this embodiment is further described below.

[0035] When the outdoor unit is powered on, Figure 5 The independent switching power supply circuit 4 starts to work. Figure 4The control unit 4 in the power supply is powered. At this time, if the control unit 4 does not receive the power-on signal, it will remain Figure 2 The first relay K401, the second relay K402, and the third relay K403 in the relay control circuit 2 are in the disconnected state, so that the drive circuit 1 at the rear end of the relay remains in the power-off state and the connection with the live and neutral wires is disconnected. At this time, there is no potential difference between the power device in the drive circuit 1 and the refrigerant radiator. Enter the standby state.

[0036] When the control unit 3 receives the power-on signal, the control unit 3 first controls the first relay K401 and the second relay K402 to be turned on, and at this time, the bus capacitor C2 in the drive circuit 1 is charged through the current limiting resistor R401. After the charging delay is set for a predetermined time, the control unit 3 controls the third relay K403 to be turned on to short-circuit the first relay K401 and the current limiting resistor R401, wherein the value range of the predetermined time can be determined according to the actual situation. Then the control unit 3 controls the first relay K401 to be turned off, reducing the power consumption of the switch power supply during operation and entering the normal operation state.

[0037] During normal operation, when the control unit 3 receives the shutdown signal and confirms that all system functions have stopped, the control unit 3 outputs a control signal to enable the relay control circuit 2 to control the second relay K402 and the third relay K403 to disconnect the drive circuit 1 from the live and neutral wires. At this time, there is no potential difference between the power devices in the drive circuit 1 and the refrigerant radiator, and the system enters the standby state again.

[0038] The above is only a specific implementation method of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. All technical solutions that fall within the scope defined by the claims of the present invention fall within the protection scope of the present invention.

Claims

1. The standby power supply circuit of the air conditioner outdoor unit is characterized in that: include: A driving circuit for driving a power device; A relay control circuit, whose output end is connected to the input end of the drive circuit, and is used to control the working state of the power device, wherein the working state includes a standby state and a normal working state; A control unit, whose signal output terminal is connected to the corresponding signal input terminal of the relay control circuit, and is used to control the on and off of the corresponding relay in the relay control circuit; The switching power supply circuit is used to provide power to the relay control circuit and the control unit.

2. The standby power supply circuit of the air conditioner outdoor unit according to claim 1, characterized in that: The drive circuit includes a first single-phase bridge rectifier DB2 and a power device connected to the output end of the first single-phase bridge rectifier, and the power device includes a power diode, an IGBT and an IPM module; the input end of the first single-phase bridge rectifier constitutes the input end of the entire drive circuit, and a bus capacitor C2 is connected between the power diode and the IGBT.

3. The standby power supply circuit of the air conditioner outdoor unit according to claim 1, characterized in that: The relay control circuit includes a first relay K401, a second relay K402, a third relay K403, diodes VD1, VD2, VD3 and a current-limiting resistor R401; the contact loop of the first relay K401 is connected in series with the current-limiting resistor R401 and then connected to the live wire, and the coil of the first relay K401 is connected in parallel with the diode VD1, one end of which is connected to the first signal input terminal, and the other end is connected to the 12V power supply; the contact loop of the second relay K402 is connected to the neutral line, and the coil of the second relay K402 is connected in parallel with the diode VD2, one end of which is connected to the second signal input terminal, and the other end is connected to the 12V power supply; the contact loop of the third relay K403 is used to short-circuit the current-limiting resistor R401 and the first relay K401 in the normal working state, and the coil of the third relay K403 is connected in parallel with the diode VD3, one end of which is connected to the third signal input terminal, and the other end is connected to the 12V power supply.

4. The standby power supply circuit of the air conditioner outdoor unit according to claim 3, characterized in that: The first signal output terminal, the second signal output terminal and the third signal output terminal of the control unit are respectively connected to the first signal input terminal, the second signal input terminal and the third signal input terminal of the relay control circuit, and are used to control the working states of the first relay K401, the second relay K402 and the third relay K403; when in the standby state, the control unit controls the first relay K401, the second relay K402 and the third relay K403 to be in the disconnected state, so that the drive circuit remains in the power-off state; when in the normal working state, the control unit controls the moving and static contacts of the third relay K403 to be connected and conducted, the moving and static contacts of the second relay K402 to be connected and conducted, and the moving and static contacts of the first relay K401 to be disconnected.

5. The standby power supply circuit of the air conditioner outdoor unit according to claim 1, characterized in that: The switching power supply circuit includes a second single-phase bridge rectifier DB1, a filter capacitor C1 and a switching power supply; the input port of the second single-phase bridge rectifier is connected to the mains, and the output port is connected to the input port of the switching power supply; the filter capacitor C1 is connected between the output ports of the second single-phase bridge rectifier; the switching power supply has three-level output, namely 5V, 12V, and 15V output, wherein the 5V output is used to supply the control unit, the 12V output is used to supply the relay control circuit, and the 15V output is used to supply the drive circuit.

6. The standby power supply circuit of the air conditioner outdoor unit according to claim 5, characterized in that: The switching power supply includes: an isolation transformer T1, a switch IC D1, diodes VD5-VD7, capacitors C4-C6, and transformer secondary output power supplies 15V, 12V, and 5V; wherein the diode VD5 and the capacitor C4 are connected to the first group of secondary outputs of the transformer to output a 15V power supply; the diode VD6 and the capacitor C5 are connected to the second group of secondary outputs of the transformer to output a 12V power supply; the diode VD7 and the capacitor C6 are connected to the third group of secondary outputs of the transformer to output a 5V power supply; the 15V, 12V, and 5V power supplies are shared by a common ground, and are shared by a common ground with the drive circuit and the control unit; the reference ground of the transformer primary switch IC D1 is connected to the negative output of the second single-phase bridge rectifier and is isolated from the secondary ground by an isolation transformer.

7. A method for controlling a power supply circuit, wherein the power supply circuit comprises a standby power supply circuit for an air conditioner outdoor unit according to any one of claims 1 to 6, characterized in that: The method comprises: When the control unit does not receive the power-on signal, the control unit outputs the first control signal, the second control signal, and the third control signal to the first relay K401, the second relay K402, and the third relay K403, respectively, so as to control the moving and static contacts of the first relay K401, the second relay K402, and the third relay K403 to remain in an open state, so that the connection between the drive circuit and the live wire L and the neutral wire N is disconnected, and the drive circuit remains in a power-off state and enters a standby state; When the control unit receives the power-on signal, the control unit first controls the moving and static contacts of the first relay K401 and the second relay K402 to be connected and conducted. At this time, the bus capacitor C2 in the drive circuit is charged through the current limiting resistor R401; after the charging delay is a predetermined time, the control unit sends a fourth control signal to control the moving and static contacts of the third relay K403 to be connected and conducted, so as to short-circuit the first relay K401 and the current limiting resistor R401; then the control unit sends a fifth control signal to control the moving and static contacts of the first relay K401 to be disconnected and enter a normal working state.

8. The control method of the power supply circuit according to claim 7, characterized in that: The method also includes: in normal working state, when the control unit receives a shutdown signal, the control unit outputs a control signal to disconnect the connection between the moving and static contacts of the second relay K402 and the third relay K403, so that the drive circuit is in a power-off state and enters a standby state again.

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