Air conditioner outdoor unit controller, protection device and method thereof and air conditioner

Abstract

The invention discloses an air conditioner outdoor unit controller, a protection device and method thereof and an air conditioner, and the device comprises a control unit which controls the on or off of a low-frequency discharge unit according to the size of surge voltage at the front end of a rectifier bridge; when the low-frequency discharge unit is conducted, low-frequency interference in the surge voltage is filtered out, and first filtered-out voltage at the front end of the rectifier bridge is obtained; the high-frequency absorption unit is used for filtering high-frequency interference in the first filtering voltage at the front end of the rectifier bridge when the low-frequency discharge unit is switched on, so that second filtering voltage at the front end of the rectifier bridge is obtained; and when the low-frequency discharge unit is not conducted, filtering high-frequency interference in the surge voltage to obtain a third filtered voltage at the front end of the rectifier bridge. According to the scheme, the high-frequency interference and the low-frequency interference of the surge voltage of the alternating current input side of the air conditioner outdoor unit controller are filtered out respectively, the bus voltage is prevented from being too high, and reliable protection of the air conditioner outdoor unit controller is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of air conditioners, and specifically relates to a protection device and method for an air conditioner outdoor unit controller, an air conditioner outdoor unit controller and an air conditioner, and more particularly to a device and method for improving the reliability of an air conditioner outdoor unit controller, an air conditioner outdoor unit controller and an air conditioner. Background Art

[0002] Since the development of the variable frequency outdoor unit of the air conditioner, the after-sales failure rate of the power devices of the inverter in the air conditioner outdoor unit controller has always ranked among the top (accounting for about 25%). With the introduction of domestic power components, related problems may be further aggravated. At present, the after-sales failure rate can only be controlled by improving device specifications or using imported devices. This cannot eliminate such problems while increasing costs.

[0003] The above contents are only used to assist in understanding the technical solution of the present invention and do not constitute an admission that the above contents are prior art. Summary of the invention

[0004] The object of the present invention is to provide a protection device for an air conditioner outdoor unit controller, an air conditioner outdoor unit controller and an air conditioner and a protection method for the air conditioner outdoor unit controller thereof, so as to solve the problem that when a hardware protection method is adopted, it is necessary to improve the hardware specifications or add additional protection circuits, which is costly and cannot prevent the occurrence of faults. The high-frequency interference and low-frequency interference of the surge voltage on the AC input side of the air conditioner outdoor unit controller are filtered out respectively, so that the bus voltage of the air conditioner outdoor unit controller is within a safe voltage range, and the bus voltage is prevented from being too high. The cost is low and the reliable protection of the air conditioner outdoor unit controller can be achieved.

[0005] The present invention provides a protection device for an air conditioner outdoor unit controller, the air conditioner outdoor unit controller has a rectifier bridge; the protection device for the air conditioner outdoor unit controller is arranged at the front end of the rectifier bridge in the air conditioner outdoor unit controller; the protection device for the air conditioner outdoor unit controller comprises: a sampling unit, a low-frequency discharge unit, a high-frequency absorption unit, and a control unit; the low-frequency discharge unit and the high-frequency absorption unit are connected and are both arranged at the front end of the rectifier bridge; wherein the sampling unit is used to sample a surge voltage from the AC power input side of the front end of the rectifier bridge, and record it as the surge voltage of the front end of the rectifier bridge; the control ... The voltage controls the conduction or shutoff of the low-frequency discharge unit; the low-frequency discharge unit is used to filter out the low-frequency interference in the surge voltage at the front end of the rectifier bridge when the low-frequency discharge unit itself is turned on, so as to obtain the first filtered voltage at the front end of the rectifier bridge; the high-frequency absorption unit is used to filter out the high-frequency interference in the first filtered voltage at the front end of the rectifier bridge when the low-frequency discharge unit is turned on, so as to obtain the second filtered voltage at the front end of the rectifier bridge; when the low-frequency discharge unit is not turned on, the high-frequency interference in the surge voltage at the front end of the rectifier bridge is filtered out, so as to obtain the third filtered voltage at the front end of the rectifier bridge.

[0006] In some embodiments, the low-frequency discharge unit includes: a first discharge module; the high-frequency absorption unit includes: a first RC module; wherein the input end of the first discharge module is used to receive the surge voltage at the front end of the rectifier bridge; the output end of the first discharge module is connected to the input end of the first RC module; the output end of the first RC module is connected to the front end of the rectifier bridge.

[0007] In some embodiments, the low-frequency discharge unit further includes: a second discharge module; wherein the output end of the first discharge module is also connected to the input end of the second discharge module; and the output end of the second discharge module is connected to the front end of the rectifier bridge.

[0008] In some embodiments, the high-frequency absorption unit further includes: a second RC module; wherein the input end of the first discharge module is also connected to the input end of the second RC module; the output end of the second RC module is connected to the input end of the first RC module; wherein, when the low-frequency discharge unit further includes a second discharge module, the first discharge module is connected in parallel with the second RC module, and the second discharge module is connected in parallel with the first RC module; and the on-voltage of the first discharge module is the same as the on-voltage of the second discharge module.

[0009] In some embodiments, the first RC module includes: a first resistor and a first capacitor; the second RC module includes: a second resistor and a second capacitor; the resistance of the first resistor is greater than the resistance of the second resistor; wherein the output end of the first discharge module is connected to the first connection end of the first resistor; the second connection end of the first resistor is connected to the first connection end of the first capacitor; the second connection end of the first capacitor, as the output end of the first RC module, is connected to the front end of the rectifier bridge; the input end of the first discharge module is also connected to the first connection end of the second resistor; the second connection end of the second resistor is connected to the first connection end of the second capacitor; the second connection end of the second capacitor is connected to the first connection end of the first resistor.

[0010] In some embodiments, when the low-frequency discharge unit includes a first discharge module and a second discharge module, and the high-frequency absorption unit includes a first RC module and a second RC module, the control unit controls the on or off of the low-frequency discharge unit according to the size of the surge voltage at the front end of the rectifier bridge, including: determining whether the surge voltage at the front end of the rectifier bridge is greater than the on-voltage of a single discharge module in the first discharge module and the second discharge module; if it is determined that the surge voltage at the front end of the rectifier bridge is not greater than the on-voltage of a single discharge module in the first discharge module and the second discharge module, then controlling both the first discharge module and the second discharge module to be turned off; if it is determined that the surge voltage at the front end of the rectifier bridge is greater than the on-voltage of a single discharge module in the first discharge module and the second discharge module, then controlling both the first discharge module and the second discharge module to be turned off; If the surge voltage of the front end of the rectifier bridge is greater than the on-voltage of a single discharge module in the first discharge module and the second discharge module, it is determined whether the surge voltage at the front end of the rectifier bridge is greater than the sum of the on-voltages of the two discharge modules in the first discharge module and the second discharge module; if it is determined that the surge voltage at the front end of the rectifier bridge is greater than the sum of the on-voltages of the two discharge modules in the first discharge module and the second discharge module, the first discharge module and the second discharge module are controlled to be turned on; if it is determined that the surge voltage at the front end of the rectifier bridge is not greater than the sum of the on-voltages of the two discharge modules in the first discharge module and the second discharge module, the first discharge module is controlled to be turned on, and the second discharge module is controlled to be turned off.

[0011] Matching the above device, the present invention further provides an air conditioner outdoor unit controller and an air conditioner, including: the protection device of the air conditioner outdoor unit controller described above.

[0012] Matching the above-mentioned air conditioner outdoor unit controller and air conditioner, the present invention provides a protection method for an air conditioner outdoor unit controller on another aspect, comprising: sampling a surge voltage from the AC power input side of the front end of the rectifier bridge, and recording it as the surge voltage of the front end of the rectifier bridge; controlling the on or off of the low-frequency discharge unit according to the size of the surge voltage of the front end of the rectifier bridge; wherein, through the low-frequency discharge unit, when it is turned on, the low-frequency interference in the surge voltage of the front end of the rectifier bridge is filtered out to obtain a first filtered voltage of the front end of the rectifier bridge; through the high-frequency absorption unit, when the low-frequency discharge unit is turned on, the high-frequency interference in the first filtered voltage of the front end of the rectifier bridge is filtered out to obtain a second filtered voltage of the front end of the rectifier bridge; through the high-frequency absorption unit, when the low-frequency discharge unit is not turned on, the high-frequency interference in the surge voltage of the front end of the rectifier bridge is filtered out to obtain a third filtered voltage of the front end of the rectifier bridge.

[0013] In some embodiments, when the low-frequency discharge unit includes a first discharge module and a second discharge module, and the high-frequency absorption unit includes a first RC module and a second RC module, the on or off of the low-frequency discharge unit is controlled according to the size of the surge voltage at the front end of the rectifier bridge, including: determining whether the surge voltage at the front end of the rectifier bridge is greater than the on-voltage of a single discharge module in the first discharge module and the second discharge module; if it is determined that the surge voltage at the front end of the rectifier bridge is not greater than the on-voltage of a single discharge module in the first discharge module and the second discharge module, then controlling both the first discharge module and the second discharge module to be turned off; if it is determined that the surge voltage at the front end of the rectifier bridge is greater than the on-voltage of a single discharge module in the first discharge module and the second discharge module, then controlling both the first discharge module and the second discharge module to be turned off; If the surge voltage at the front end of the rectifier bridge is greater than the on-voltage of a single discharge module in the first discharge module and the second discharge module, it is determined whether the surge voltage at the front end of the rectifier bridge is greater than the sum of the on-voltages of the two discharge modules in the first discharge module and the second discharge module; if it is determined that the surge voltage at the front end of the rectifier bridge is greater than the sum of the on-voltages of the two discharge modules in the first discharge module and the second discharge module, the first discharge module and the second discharge module are both controlled to be turned on; if it is determined that the surge voltage at the front end of the rectifier bridge is not greater than the sum of the on-voltages of the two discharge modules in the first discharge module and the second discharge module, the first discharge module is controlled to be turned on, and the second discharge module is controlled to be turned off.

[0014] Therefore, the scheme of the present invention, through the protection of the bus voltage of the air conditioner outdoor unit controller, sets a protection device at the front end of the rectifier bridge in the air conditioner outdoor unit controller, the protection device has a low-frequency discharge unit (such as a discharge tube) arranged in series, and a high-frequency absorption unit (such as a resistor and a capacitor arranged in series) connected to the low-frequency discharge unit, and controls the opening and closing of the low-frequency discharge unit according to the size of the surge voltage on the AC input side of the rectifier bridge front end in the air conditioner outdoor unit controller, so as to filter out the low-frequency interference by the low-frequency discharge unit, and absorb the high-frequency interference by the high-frequency absorption unit, so that the bus voltage of the air conditioner outdoor unit controller is within the safe voltage range; thus, by filtering out the high-frequency interference and the low-frequency interference of the surge voltage on the AC input side of the air conditioner outdoor unit controller respectively, the bus voltage of the air conditioner outdoor unit controller is within the safe voltage range, and the bus voltage is avoided from being too high, and the cost is low and reliable protection of the air conditioner outdoor unit controller can be achieved.

[0015] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the present invention.

[0016] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of an embodiment of a protection device for an air conditioner outdoor unit controller of the present invention;

[0018] Figure 2 It is a structural schematic diagram of an embodiment of a high-voltage absorption circuit of the present invention;

[0019] Figure 3 A flow chart of an embodiment of a method for improving the reliability of an air conditioner outdoor unit controller according to the present invention;

[0020] Figure 4 A schematic flow chart of an embodiment of a method for protecting an outdoor unit controller of an air conditioner according to the present invention;

[0021] Figure 5 The figure is a flow chart of an embodiment of controlling the on or off of the low-frequency discharge unit in the method of the present invention. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of 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.

[0023] Considering that, for the failure of the power devices of the inverter in the air conditioner outdoor unit controller, the use of hardware protection requires improving the hardware specifications or adding additional protection circuits, which is costly and cannot prevent the occurrence of failures. If a new surge protection control circuit is used, the failure rate is expected to be less than 5%.

[0024] However, the operating conditions of household air conditioners are complex and the power grid environment is unstable. Years of after-sales experience have shown that the power grids of household air conditioners sold in my country still have a large number of problems such as lightning strikes, harmonics and voltage drops.

[0025] In addition, during the reliability verification of the series air conditioner outdoor unit, it was found that the bus voltage of the air conditioner outdoor unit controller can reach 780V in the case of lightning surge, which has exceeded the withstand voltage of the power devices in the inverter, thus affecting the after-sales failure rate. The rear voltage refers to the voltage at the intelligent power module (IPM) of the compressor on the rear side of the DC bus.

[0026] Therefore, the scheme of the present invention proposes a protection device for an air-conditioning outdoor unit controller, specifically a device for improving the reliability of the air-conditioning outdoor unit controller, and designs two channels (i.e., a high-frequency channel and a low-frequency channel) to filter out corresponding interference. This can solve the problem of increasing costs by improving hardware specifications or adding additional protection circuits through hardware protection in related schemes, thereby reducing costs and achieving protection of the air-conditioning outdoor unit controller; it can also solve the problem of excessive bus voltage of the air-conditioning outdoor unit controller in the event of a harmonic surge, thereby improving the reliability and safety of the air-conditioning outdoor unit controller.

[0027] According to an embodiment of the present invention, a protection device for an outdoor unit controller of an air conditioner is provided. Figure 1 The structure diagram of an embodiment of the device of the present invention is shown in FIG. The air conditioner outdoor unit controller has a rectifier bridge; the protection device of the air conditioner outdoor unit controller, such as a high-voltage absorption circuit, is arranged at the front end of the rectifier bridge in the air conditioner outdoor unit controller, and is used to filter out high and low frequency interference in the surge voltage on the AC input side of the front end of the rectifier bridge in the air conditioner outdoor unit controller; in the scheme of the present invention, Figure 1 As shown, the protection device of the air conditioner outdoor unit controller includes: a sampling unit, a low-frequency discharge unit (such as a discharge tube), a high-frequency absorption unit (such as a resistor and a capacitor arranged in series), and a control unit (such as a peripheral circuit of the discharge tube); the low-frequency discharge unit and the high-frequency absorption unit are connected and are both arranged at the front end of the rectifier bridge.

[0028] Wherein, the sampling unit is used to sample the surge voltage from the AC power input side of the front end of the rectifier bridge, and record it as the surge voltage of the front end of the rectifier bridge.

[0029] The control unit is used to control the on or off of the low-frequency discharge unit according to the size of the surge voltage at the front end of the rectifier bridge.

[0030] The low-frequency discharge unit is arranged at the front end of the rectifier bridge in the air conditioner outdoor unit controller, and is used to filter out the low-frequency interference in the surge voltage at the front end of the rectifier bridge when the low-frequency discharge unit itself is turned on (that is, when the low-frequency discharge unit itself is turned on under the control of the control unit), so as to obtain the first filtered voltage at the front end of the rectifier bridge, so as to transmit the first filtered voltage at the front end of the rectifier bridge to the high-frequency absorption unit, or transmit the first filtered voltage at the front end of the rectifier bridge to the rectifier bridge of the air conditioner outdoor unit controller.

[0031] The high-frequency absorption unit is arranged at the front end of the rectifier bridge in the air conditioner outdoor unit controller and is connected to the low-frequency discharge unit. It is used to filter out the high-frequency interference in the first filtered voltage at the front end of the rectifier bridge when the low-frequency discharge unit is turned on, and obtain the second filtered voltage at the front end of the rectifier bridge, so as to transmit the second filtered voltage at the front end of the rectifier bridge to the rectifier bridge of the air conditioner outdoor unit controller.

[0032] The high-frequency absorption unit is also used to filter out high-frequency interference in the surge voltage at the front end of the rectifier bridge when the low-frequency discharge unit is not turned on, so as to obtain a third filtered voltage at the front end of the rectifier bridge, and transmit the third filtered voltage at the front end of the rectifier bridge to the rectifier bridge of the air conditioner outdoor unit controller.

[0033] Since there will be two types of interference in the surge situation, high-frequency interference and low-frequency interference, the solution of the present invention designs two channels (i.e., a high-frequency channel and a low-frequency channel) to filter out the corresponding interference for the above two types of interference. In the solution of the present invention, interference with a voltage greater than 1500V is considered to be low-frequency interference, whereas interference with a voltage lower than 1500V is considered to be high-frequency interference, wherein the high-frequency channel is used to filter out high-frequency interference, and the low-frequency channel is used to filter out low-frequency interference. The solution of the present invention can always maintain the bus voltage of the air-conditioning outdoor unit controller within the withstand voltage range of the main board in the air-conditioning outdoor unit controller, thereby ensuring that the main board in the air-conditioning outdoor unit controller is not damaged when the bus voltage is within the withstand voltage range, thereby reducing the after-sales failure rate of the air-conditioning outdoor unit.

[0034] In some embodiments, the low-frequency discharge unit includes: a first discharge module (such as a discharge tube G1); the high-frequency absorption unit includes: a first RC module (such as a resistor R2 and a capacitor C2); wherein the input end of the first discharge module is used to receive the surge voltage at the front end of the rectifier bridge; the output end of the first discharge module is connected to the input end of the first RC module; the output end of the first RC module is connected to the front end of the rectifier bridge.

[0035] In the solution of the present invention, when a discharge tube (such as the discharge tube G1) is already turned on, only a set of RC filtering circuits (such as the resistor R2 and the capacitor C2) is needed to absorb the high-frequency spike voltage that cannot be filtered out by the turned-on discharge tube (such as the discharge tube G1), thereby ensuring that the mainboard components of the air conditioner outdoor unit controller are not damaged.

[0036] In some embodiments, the first RC module includes: a first resistor (such as resistor R2) and a first capacitor (such as capacitor C2). The output end of the first discharge module is connected to the first connection end of the first resistor; the second connection end of the first resistor is connected to the first connection end of the first capacitor; the second connection end of the first capacitor, as the output end of the first RC module, is connected to the front end of the rectifier bridge.

[0037] In the solution of the present invention, an RC filtering circuit is adopted to form a high-frequency channel, which solves the problem of a sharp increase in the bus voltage of the main board in the air-conditioning outdoor unit controller when the main board in the air-conditioning outdoor unit controller is subject to high-frequency interference, thereby reducing costs and achieving protection of the air-conditioning outdoor unit controller.

[0038] In some embodiments, the low-frequency discharge unit further includes: a second discharge module (such as a discharge tube G2), wherein the output end of the first discharge module is also connected to the input end of the second discharge module; and the output end of the second discharge module is connected to the front end of the rectifier bridge.

[0039] Figure 2 FIG. 1 is a schematic diagram of a high voltage absorption circuit according to an embodiment of the present invention. Figure 2 The new type of surge protection circuit shown in the figure first establishes the maximum surge protection capability of the EMI circuit by connecting two discharge tubes (i.e., discharge tube G1 and discharge tube G2) in series. The new type of surge protection circuit can filter out the peak voltage from greater than 0V to protect the mainboard of the air conditioner outdoor controller. Compared with the related scheme that can only provide protection when the voltage is greater than 4680V, ​​the protection capability of the mainboard of the air conditioner outdoor controller is greatly improved. The new type of surge protection circuit can control the voltage difference between the two discharge tubes (i.e., discharge tube G1 and discharge tube G2) when working through the peripheral circuit, thereby completing the conversion of the high-frequency channel and the low-frequency channel in a very short time. Among them, the peripheral circuit is a circuit of the RC module part connected in parallel with the two discharge tubes. In the scheme of the present invention, the high-frequency channel is actually a channel for filtering high-frequency interference, and the low-frequency channel is a channel for filtering low-frequency interference, which can filter out high-frequency interference and low-frequency interference respectively.

[0040] The solution of the present invention provides a new type of surge protection circuit, such as a high-voltage absorption circuit, which is used for the normal and stable operation of the air conditioner when the power grid is unstable during the later user use. The high-voltage absorption circuit connects two discharge tubes in series, and connects resistors and capacitors with specific parameters in parallel at both ends of the two discharge tubes. By adjusting the ratio of the resistor and the capacitor, the on and off state of the discharge tube is controlled, thereby effectively reducing high-frequency surges and residual pressure, and ensuring that the power frequency withstand voltage meets the requirements. Among them, the on and off of the discharge tube is directly affected by the on-voltage of the discharge tube itself; the on and off of the discharge tube is also affected by the withstand voltage of the RC module. Adjust the ratio of the resistor and the capacitor, for example: the resistance of the resistor with a larger resistance value in the two RC modules and the resistance of the resistor with a smaller resistance value can be 15:1, and the withstand voltage value of the resistor with a larger resistance value is 100 times the on-voltage of the discharge tube. The high-voltage absorption circuit can be triggered in a unique manner and the absorption element is connected in parallel on the peripheral circuit. At this time, it can suppress LC resonance (i.e., the resonance generated by inductance and capacitance) and enhance its anti-interference ability.

[0041] In some embodiments, the high-frequency absorption unit further includes: a second RC module (such as a resistor R1 and a capacitor C1). The input end of the first discharge module is also connected to the input end of the second RC module; the output end of the second RC module is connected to the input end of the first RC module.

[0042] Wherein, when the low-frequency discharge unit further includes a second discharge module, the first discharge module is connected in parallel with the second RC module, and the second discharge module is connected in parallel with the first RC module; and the on-voltage of the first discharge module is the same as the on-voltage of the second discharge module, and the resistance of the second RC module is greater than the resistance of the first RC module.

[0043] In the solution of the present invention, when the discharge tube G1 and the discharge tube G2 are not turned on, the maximum voltage that the mainboard of the air conditioner outdoor unit controller needs to withstand is relatively high, so two sets of RC filters are required to reduce the bus voltage to ensure that the mainboard components of the air conditioner outdoor unit controller are not damaged.

[0044] In some embodiments, the first RC module includes: a first resistor (such as resistor R2) and a first capacitor (such as capacitor C2); the second RC module includes: a second resistor (such as resistor R1) and a second capacitor (such as capacitor C1); the resistance value of the first resistor is greater than the resistance value of the second resistor.

[0045] Among them, the output end of the first discharge module is connected to the first connection end of the first resistor; the second connection end of the first resistor is connected to the first connection end of the first capacitor; the second connection end of the first capacitor, as the output end of the first RC module, is connected to the front end of the rectifier bridge.

[0046] The input end of the first discharge module is also connected to the first connection end of the second resistor; the second connection end of the second resistor is connected to the first connection end of the second capacitor; and the second connection end of the second capacitor is connected to the first connection end of the first resistor.

[0047] like Figure 2 As shown, the high-voltage absorption circuit includes: a discharge tube G1, a discharge tube G2, a resistor R1, a resistor R2, a capacitor C1 and a capacitor C2. Among them, the device characteristics are: R2>>R1, C1=C2, G1=G2; that is, the resistance value of the resistor R2 is much greater than the resistance value of the resistor R1, the capacitance value of the capacitor C1 is the same as that of the capacitor C2, and the discharge performance of the discharge tube G1 and the discharge tube G2 is the same.

[0048] Among them, the first connection end of the discharge tube G1 is connected to the terminal PIN1, the second connection end of the discharge tube G1 is connected to the first connection end of the discharge tube G2, the common end of the second connection end of the discharge tube G1 and the first connection end of the discharge tube G2 is connected to the terminal PIN3, and the second connection end of the discharge tube G2 is connected to the terminal PIN2. The resistor R1 and the capacitor C1 are connected in series between the terminal PIN1 and the terminal PIN3, and the resistor R2 and the capacitor C2 are connected in series between the terminal PIN3 and the terminal PIN2. The terminal PIN1 is connected to the incoming line end of the AC power supply, and the terminal PIN2 is connected close to the rectifier bridge end (that is, the terminal PIN2 is connected to the front end of the rectifier bridge).

[0049] Among them, the specific parameters can be adjusted according to the actual situation. The national standard lightning surge standard is 2000V. For example, if it is designed according to twice the national standard interference, the voltage interference is within 4000V. At this time, two discharge tubes with a voltage of 1500V are selected in series. Therefore, the resistors should be 150KΩ and 10KΩ, and the capacitors should be 1nF / 2000V (2000V is the capacitor's maximum withstand voltage). Component selection relationship: single discharge tube withstand voltage: (maximum interference voltage-1000) / 2; capacitor: capacitance is 1nF, withstand voltage: maximum interference voltage / 2; resistor values ​​are: R1: (maximum interference voltage-1000) / 20, R2: R1 / 10.

[0050] In the scheme of the present invention, the residual voltage is absorbed by modifying the anti-surge circuit part of the front stage of the electromagnetic interference (EMI) circuit (i.e., the EMI front-end circuit), and the protection of different segments (such as high frequency band and low frequency band) is completed by using a double discharge tube series connection and peripheral circuit adjustment method; this method can improve the performance of the lightning protection circuit, can well solve the problem of insufficient withstand voltage of most devices, and can greatly reduce the failure rate of power devices in the inverter of the air conditioner outdoor unit controller.

[0051] In some embodiments, when the low-frequency discharge unit includes a first discharge module and a second discharge module, and the high-frequency absorption unit includes a first RC module and a second RC module, the control unit controls the on or off of the low-frequency discharge unit according to the magnitude of the surge voltage at the front end of the rectifier bridge, including:

[0052] The control unit is further specifically used to determine whether the surge voltage at the front end of the rectifier bridge is greater than the turn-on voltage of a single discharge module in the first discharge module and the second discharge module.

[0053] The control unit is further specifically used to control both the first discharge module and the second discharge module to be turned off if it is determined that the surge voltage at the front end of the rectifier bridge is not greater than the turn-on voltage of a single discharge module in the first discharge module and the second discharge module.

[0054] The control unit is specifically used to determine whether the surge voltage at the front end of the rectifier bridge is greater than the sum of the on-voltages of the two discharge modules in the first discharge module and the second discharge module if it is determined that the surge voltage at the front end of the rectifier bridge is greater than the on-voltage of a single discharge module in the first discharge module and the second discharge module.

[0055] The control unit is specifically used to control both the first discharge module and the second discharge module to be turned on when the surge voltage at the front end of the rectifier bridge is greater than the turn-on voltage of a single discharge module in the first discharge module and the second discharge module, if it is determined that the surge voltage at the front end of the rectifier bridge is greater than the sum of the turn-on voltages of the two discharge modules in the first discharge module and the second discharge module.

[0056] The control unit is specifically used to control the first discharge module to be turned on and the second discharge module to be turned off when the surge voltage at the front end of the rectifier bridge is greater than the turn-on voltage of a single discharge module in the first discharge module and the second discharge module, if it is determined that the surge voltage at the front end of the rectifier bridge is not greater than the sum of the turn-on voltages of the two discharge modules in the first discharge module and the second discharge module.

[0057] In the scheme of the present invention, Figure 2 The new surge protection circuit shown in the figure achieves comprehensive protection for the mainboard of the air conditioner outdoor unit controller by switching the low-frequency channel and the high-frequency channel at different voltage levels. Figure 2 The specific working principle of the protection mechanism of the new surge protection circuit shown is explained in detail.

[0058] Among them, when there is a surge voltage on the AC input side of the rectifier bridge front end of the air conditioner outdoor unit controller, the bus voltage of the air conditioner outdoor unit controller itself is in a low voltage state (that is, the surge voltage is less than the working voltage of a single discharge tube) protection mechanism: the low-frequency channel is turned on and the high-frequency channel is turned off. In this process, only the capacitive circuit is used for absorption. At this time, the resistor and the capacitor are connected in series (such as the resistor R1 and the capacitor C1 in series, and the resistor R2 and the capacitor C2 in series) to form an RC filter to filter out the peak voltage in this voltage state, thereby achieving the stability of the new surge protection circuit. In addition, the mainboard of the air conditioner outdoor unit controller only relies on its own voltage resistance to ensure the normal operation of the controller, otherwise it will be damaged; because the discharge tube G1 and the discharge tube G2 are not turned on at this time, the maximum voltage that the mainboard of the air conditioner outdoor unit controller needs to withstand is relatively high, so two sets of RC filters are required to reduce the bus voltage, thereby ensuring that the mainboard components of the air conditioner outdoor unit controller are not damaged.

[0059] When there is a surge voltage on the AC input side of the front end of the rectifier bridge of the air conditioner outdoor controller, the bus voltage of the air conditioner outdoor controller itself is in a medium voltage state (i.e., the surge voltage reaches the conduction voltage of a single discharge tube). The protection mechanism is as follows: at this time, the high-frequency channel and the low-frequency channel work simultaneously. At this time, the current first passes through a discharge tube such as the discharge tube G1 (i.e., first passes through the low-frequency channel), and then passes through another discharge tube such as the capacitive circuit outside the discharge tube G2, such as the resistor R2 and the capacitor C2 (i.e., then passes through the high-frequency channel), and finally reaches the EMI circuit of the back stage of the mainboard. At this time, since the discharge tube (such as the discharge tube G1) is already turned on in the new surge protection circuit, only a set of RC filter circuits (such as the resistor R2 and the capacitor C2) is needed to absorb the high-frequency spike voltage that cannot be filtered out by the turned-on discharge tube (such as the discharge tube G1). Among them, the discharge tube G1 connected in parallel with the RC module with a larger resistance value in the two RC modules is turned on first, as the incoming line end of the power supply, and the RC module with a smaller resistance value in the two RC modules is connected to the front end of the rectifier bridge.

[0060] When there is a surge voltage on the AC input side of the rectifier bridge front end of the air conditioner outdoor unit controller, the bus voltage of the air conditioner outdoor unit controller itself is in a high voltage state (the conduction voltage satisfies the conduction voltage of the two discharge tubes). The protection mechanism: at this time, the new surge protection circuit only works through the low-frequency channel, and the two discharge tubes (i.e., discharge tube G1 and discharge tube G2) are both in the conduction state. At this time, the current completely passes through the two discharge tubes in series (i.e., discharge tube G1 and discharge tube G2), so the capacitive circuit (i.e., resistor R1 and capacitor C1, resistor R2 and capacitor C2) is short-circuited. At this time, the capacitive circuit is in a short-circuit state, and all peak voltages are absorbed by the two discharge tubes.

[0061] In the scheme of the present invention, the reason for using two discharge tubes in series is that through a large number of tests, it is found that the general low-frequency interference is higher than 1500V, so two discharge tubes are used in series. When one discharge tube is turned on, the interference voltage will be reduced by 1500V, and the low-frequency interference will be converted into high-frequency interference. Under normal circumstances, the interference voltage is less than 4000V, and the national standard is 2000V, so the interference filtering effect is completed on this basis. The outdoor controller can operate stably under a surge voltage higher than the national standard of 2000V; the interference filtering specifically includes: first, the RC module itself can absorb the interference; in addition, when the discharge tube is turned on, the interference is transmitted to the ground, thereby filtering the interference. To a large extent, it can be ensured that the interference will not damage the mainboard. In the scheme of the present invention, two discharge tubes are connected in series to form a low-frequency channel. The low-frequency channel solves the problem of a sharp increase in the bus voltage of the mainboard in the air conditioner outdoor controller when the mainboard is subjected to low-frequency interference, thereby improving the reliability and safety of the air conditioner outdoor controller.

[0062] In the scheme of the present invention, the working voltages of the above three working states are inconsistent, the purpose is to ensure that the bus voltage of the air conditioner outdoor unit controller is maintained within the tolerable range of the mainboard of the air conditioner outdoor unit controller (including the withstand voltage range of the mainboard components) under different surge voltage conditions. Therefore, under the above three different conditions, by quickly switching the low-frequency channel and the high-frequency channel in a short time, the entire circuit can respond quickly when facing surge signals of different frequencies, thereby absorbing the peak voltage under lightning surge conditions. Therefore, it is ensured that the bus voltage of the controller is always maintained within the withstand voltage of the mainboard components under various frequency bands, which can largely resist the potential threat brought by lightning surges.

[0063] Figure 3 The figure is a flow chart of an embodiment of a method for improving the reliability of an air conditioner outdoor unit controller according to the present invention. Figure 2 The new surge protection circuit shown in Figure 3 As shown, the method for improving the reliability of the air conditioner outdoor unit controller includes:

[0064] Step 1: Start Figure 2 The novel surge protection circuit shown obtains the bus voltage of the air conditioner outdoor unit controller itself when there is a surge voltage on the AC input side of the rectifier bridge front end of the air conditioner outdoor unit controller, and then executes step 2.

[0065] Step 2, determine whether the surge voltage is greater than the conduction voltage of a single discharge tube among the discharge tube G1 and the discharge tube G2: if not, execute step 3; if yes, execute step 4.

[0066] Step 3: If the surge voltage is smaller than the conduction voltage of a single discharge tube among the discharge tube G1 and the discharge tube G2, the current only flows through the high-frequency channel, and at this time, the discharge tube G1 and the discharge tube G2 are not turned on.

[0067] Step 4: Determine whether the surge voltage is greater than the sum of the conduction voltages of the two discharge tubes G1 and G2: If so, execute step 5; otherwise, execute step 6.

[0068] Step 5: If the surge voltage is greater than the sum of the conduction voltages of the two discharge tubes G1 and G2, both the discharge tube G1 and G2 are controlled to be turned on, and the current only flows through the low-frequency channel.

[0069] Step 6: If the surge voltage is not greater than the sum of the conduction voltages of the two discharge tubes G1 and G2, the discharge tube G1 is controlled to be turned on, and the current first flows through the low-frequency channel and then transfers to the high-frequency channel at the PIN3 point.

[0070] In the scheme of the present invention, by Figure 2 The new anti-surge circuit shown can complete the high- and low-frequency channel conversion in a short time, so as to achieve the purpose of filtering out both high and low frequency interference, and can solve the problem of high after-sales failure rate due to the risk of damage to the controller caused by excessive bus voltage. Under different surge voltage conditions, the bus voltage of the air-conditioning outdoor unit controller can be maintained within the tolerable range of the mainboard of the air-conditioning outdoor unit controller (including the withstand voltage range of the mainboard components). By quickly switching between the low-frequency channel and the high-frequency channel in a short time, the entire circuit can respond quickly when facing surge signals of different frequencies, thereby absorbing the peak voltage under lightning surge conditions, ensuring that the bus voltage of the controller is always maintained within the withstand voltage of the mainboard components under various frequency bands, and can largely resist the potential threats brought by lightning surges.

[0071] By adopting the technical solution of the present invention, a protection device is arranged at the front end of the rectifier bridge in the air-conditioning outdoor unit controller to protect the bus voltage of the air-conditioning outdoor unit controller. The protection device has a low-frequency discharge unit (such as a discharge tube) arranged in series, and a high-frequency absorption unit (such as a resistor and a capacitor arranged in series) connected to the low-frequency discharge unit. The opening and closing of the low-frequency discharge unit is controlled according to the surge voltage on the AC input side of the front end of the rectifier bridge in the air-conditioning outdoor unit controller, so that the low-frequency discharge unit is used to filter the low-frequency interference, and the high-frequency absorption unit is used to absorb the high-frequency interference, so that the bus voltage of the air-conditioning outdoor unit controller is within a safe voltage range; thus, by filtering the high-frequency interference and the low-frequency interference of the surge voltage on the AC input side of the air-conditioning outdoor unit controller respectively, the bus voltage of the air-conditioning outdoor unit controller is within a safe voltage range, and the bus voltage is avoided from being too high. The cost is low and reliable protection of the air-conditioning outdoor unit controller can be achieved.

[0072] According to an embodiment of the present invention, an air conditioner outdoor unit controller and an air conditioner corresponding to the protection device of the air conditioner outdoor unit controller are also provided. The air conditioner outdoor unit controller and the air conditioner may include: the protection device of the air conditioner outdoor unit controller described above.

[0073] Since the processing and functions implemented by the air conditioner outdoor unit controller and the air conditioner in this embodiment basically correspond to the embodiments, principles and examples of the device, for the details not described in this embodiment, please refer to the relevant descriptions in the aforementioned embodiments and will not be repeated here.

[0074] According to an embodiment of the present invention, a protection method for an air conditioner outdoor unit controller corresponding to an air conditioner outdoor unit controller and an air conditioner is also provided. Figure 4 The flowchart of an embodiment of the method of the present invention is shown in FIG. The protection method of the air conditioner outdoor unit controller may include: step S110 to step S120.

[0075] At step S110, the sampling unit samples a surge voltage from the AC power input side of the front end of the rectifier bridge, and records it as the surge voltage of the front end of the rectifier bridge;

[0076] In step S120, the control unit controls the on or off of the low-frequency discharge unit according to the magnitude of the surge voltage at the front end of the rectifier bridge.

[0077] Among them, the low-frequency discharge unit is arranged at the front end of the rectifier bridge in the air-conditioning outdoor unit controller. When the low-frequency discharge unit is turned on, the low-frequency interference in the surge voltage at the front end of the rectifier bridge is filtered out to obtain the first filtered voltage at the front end of the rectifier bridge, so as to transmit the first filtered voltage at the front end of the rectifier bridge to the high-frequency absorption unit, or transmit the first filtered voltage at the front end of the rectifier bridge to the rectifier bridge of the air-conditioning outdoor unit controller.

[0078] The high-frequency absorption unit is arranged at the front end of the rectifier bridge in the air conditioner outdoor unit controller and is connected to the low-frequency discharge unit. Through the high-frequency absorption unit, when the low-frequency discharge unit is turned on, the high-frequency interference in the first filtered voltage at the front end of the rectifier bridge is filtered out to obtain the second filtered voltage at the front end of the rectifier bridge, so as to transmit the second filtered voltage at the front end of the rectifier bridge to the rectifier bridge of the air conditioner outdoor unit controller.

[0079] Through the high-frequency absorption unit, when the low-frequency discharge unit is not turned on, the high-frequency interference in the surge voltage at the front end of the rectifier bridge is filtered out to obtain the third filtered voltage at the front end of the rectifier bridge, so as to transmit the third filtered voltage at the front end of the rectifier bridge to the rectifier bridge of the air conditioner outdoor unit controller.

[0080] Since there will be two types of interference in the surge situation, high-frequency interference and low-frequency interference, the solution of the present invention designs two channels (i.e., a high-frequency channel and a low-frequency channel) to filter out the corresponding interference for the above two types of interference. In the solution of the present invention, interference with a voltage greater than 1500V is considered to be low-frequency interference, whereas interference with a voltage lower than 1500V is considered to be high-frequency interference, wherein the high-frequency channel is used to filter out high-frequency interference, and the low-frequency channel is used to filter out low-frequency interference. The solution of the present invention can always maintain the bus voltage of the air-conditioning outdoor unit controller within the withstand voltage range of the main board in the air-conditioning outdoor unit controller, thereby ensuring that the main board in the air-conditioning outdoor unit controller is not damaged when the bus voltage is within the withstand voltage range, thereby reducing the after-sales failure rate of the air-conditioning outdoor unit.

[0081] In some embodiments, when the low-frequency discharge unit includes a first discharge module and a second discharge module, and the high-frequency absorption unit includes a first RC module and a second RC module, the specific process of controlling the on or off of the low-frequency discharge unit by the control unit in step S120 according to the size of the surge voltage at the front end of the rectifier bridge is described in the following exemplary description.

[0082] Combine the following Figure 5 The flowchart of an embodiment of controlling the on or off of the low-frequency discharge unit in the method of the present invention further illustrates the specific process of controlling the on or off of the low-frequency discharge unit in step S120, including: steps S210 to S250.

[0083] In step S210, the control unit determines whether the surge voltage at the front end of the rectifier bridge is greater than the turn-on voltage of a single discharge module in the first discharge module and the second discharge module.

[0084] At step S220, through the control unit, if it is determined that the surge voltage at the front end of the rectifier bridge is not greater than the turn-on voltage of a single discharge module in the first discharge module and the second discharge module, the first discharge module and the second discharge module are controlled to be turned off.

[0085] At step S230, through the control unit, if it is determined that the surge voltage at the front end of the rectifier bridge is greater than the on-voltage of a single discharge module in the first discharge module and the second discharge module, it is determined whether the surge voltage at the front end of the rectifier bridge is greater than the sum of the on-voltages of the two discharge modules in the first discharge module and the second discharge module.

[0086] At step S240, through the control unit, when the surge voltage at the front end of the rectifier bridge is greater than the turn-on voltage of a single discharge module in the first discharge module and the second discharge module, if it is determined that the surge voltage at the front end of the rectifier bridge is greater than the sum of the turn-on voltages of the two discharge modules in the first discharge module and the second discharge module, the first discharge module and the second discharge module are controlled to be turned on.

[0087] At step S250, through the control unit, when the surge voltage at the front end of the rectifier bridge is greater than the turn-on voltage of a single discharge module in the first discharge module and the second discharge module, if it is determined that the surge voltage at the front end of the rectifier bridge is not greater than the sum of the turn-on voltages of the two discharge modules in the first discharge module and the second discharge module, the first discharge module is controlled to be turned on and the second discharge module is controlled to be turned off.

[0088] In the scheme of the present invention, Figure 2 The new surge protection circuit shown in the figure achieves comprehensive protection for the mainboard of the air conditioner outdoor unit controller by switching the low-frequency channel and the high-frequency channel at different voltage levels. Figure 2 The specific working principle of the protection mechanism of the new surge protection circuit shown is explained in detail.

[0089] Among them, when there is a surge voltage on the AC input side of the rectifier bridge front end of the air conditioner outdoor unit controller, the bus voltage of the air conditioner outdoor unit controller itself is in a low voltage state (that is, the surge voltage is less than the working voltage of a single discharge tube) protection mechanism: the low-frequency channel is turned on and the high-frequency channel is turned off. In this process, only the capacitive circuit is used for absorption. At this time, the resistor and the capacitor are connected in series (such as the resistor R1 and the capacitor C1 in series, and the resistor R2 and the capacitor C2 in series) to form an RC filter to filter out the peak voltage in this voltage state, thereby achieving the stability of the new surge protection circuit. In addition, the mainboard of the air conditioner outdoor unit controller only relies on its own voltage resistance to ensure the normal operation of the controller, otherwise it will be damaged; because the discharge tube G1 and the discharge tube G2 are not turned on at this time, the maximum voltage that the mainboard of the air conditioner outdoor unit controller needs to withstand is relatively high, so two sets of RC filters are required to reduce the bus voltage, thereby ensuring that the mainboard components of the air conditioner outdoor unit controller are not damaged.

[0090] When there is a surge voltage on the AC input side of the rectifier bridge front end of the air conditioner outdoor unit controller, the bus voltage of the air conditioner outdoor unit controller itself is in a medium voltage state (that is, the surge voltage reaches the conduction voltage of a single discharge tube). The protection mechanism is as follows: at this time, the high-frequency channel and the low-frequency channel work simultaneously. At this time, the current first passes through a discharge tube such as the discharge tube G1 (that is, it passes through the low-frequency channel first), and then passes through another discharge tube such as the capacitive circuit outside the discharge tube G2 such as the resistor R2 and the capacitor C2 (that is, it passes through the high-frequency channel again), and finally reaches the EMI circuit of the back stage of the mainboard. At this time, since the discharge tube (such as the discharge tube G1) is already turned on in the new surge protection circuit, only a set of RC filtering circuits (such as the resistor R2 and the capacitor C2) are needed to absorb the high-frequency spike voltage that cannot be filtered out by the turned-on discharge tube (such as the discharge tube G1).

[0091] When there is a surge voltage on the AC input side of the rectifier bridge front end of the air conditioner outdoor unit controller, the bus voltage of the air conditioner outdoor unit controller itself is in a high voltage state (the conduction voltage satisfies the conduction voltage of the two discharge tubes). The protection mechanism: at this time, the new surge protection circuit only works through the low-frequency channel, and the two discharge tubes (i.e., discharge tube G1 and discharge tube G2) are both in the conduction state. At this time, the current completely passes through the two discharge tubes in series (i.e., discharge tube G1 and discharge tube G2), so the capacitive circuit (i.e., resistor R1 and capacitor C1, resistor R2 and capacitor C2) is short-circuited. At this time, the capacitive circuit is in a short-circuit state, and all peak voltages are absorbed by the two discharge tubes.

[0092] In the scheme of the present invention, the reason for using two discharge tubes in series is that through a large number of tests, it is found that the general low-frequency interference is higher than 1500V, so two discharge tubes are used in series. When one discharge tube is turned on, the interference voltage will be reduced by 1500V, and the low-frequency interference will be converted into high-frequency interference. Under normal circumstances, the interference voltage is less than 4000V, and the national standard is 2000V, so on this basis, the interference filtering effect is completed. It can be ensured to a large extent that the interference will not damage the mainboard. In the scheme of the present invention, two discharge tubes are connected in series to form a low-frequency channel. The low-frequency channel solves the problem of a sharp increase in the bus voltage of the mainboard in the air conditioner outdoor controller when the mainboard in the air conditioner outdoor controller is subjected to low-frequency interference, thereby improving the reliability and safety of the air conditioner outdoor controller.

[0093] In the scheme of the present invention, the working voltages of the above three working states are inconsistent, the purpose is to ensure that the bus voltage of the air conditioner outdoor unit controller is maintained within the tolerable range of the mainboard of the air conditioner outdoor unit controller (including the withstand voltage range of the mainboard components) under different surge voltage conditions. Therefore, under the above three different conditions, by quickly switching the low-frequency channel and the high-frequency channel in a short time, the entire circuit can respond quickly when facing surge signals of different frequencies, thereby absorbing the peak voltage under lightning surge conditions. Therefore, it is ensured that the bus voltage of the controller is always maintained within the withstand voltage of the mainboard components under various frequency bands, which can largely resist the potential threat brought by lightning surges.

[0094] Figure 3 The figure is a flow chart of an embodiment of a method for improving the reliability of an air conditioner outdoor unit controller according to the present invention. Figure 2 The new surge protection circuit shown in Figure 3 As shown, the method for improving the reliability of the air conditioner outdoor unit controller includes:

[0095] Step 1: Start Figure 2 The novel surge protection circuit shown obtains the bus voltage of the air conditioner outdoor unit controller itself when there is a surge voltage on the AC input side of the rectifier bridge front end of the air conditioner outdoor unit controller, and then executes step 2.

[0096] Step 2, determine whether the surge voltage is greater than the conduction voltage of a single discharge tube among the discharge tube G1 and the discharge tube G2: if not, execute step 3; if yes, execute step 4.

[0097] Step 3: If the surge voltage is smaller than the conduction voltage of a single discharge tube among the discharge tube G1 and the discharge tube G2, the current only flows through the high-frequency channel, and at this time, the discharge tube G1 and the discharge tube G2 are not turned on.

[0098] Step 4: Determine whether the surge voltage is greater than the sum of the conduction voltages of the two discharge tubes G1 and G2: If so, execute step 5; otherwise, execute step 6.

[0099] Step 5: If the surge voltage is greater than the sum of the conduction voltages of the two discharge tubes G1 and G2, both the discharge tube G1 and G2 are controlled to be turned on, and the current only flows through the low-frequency channel.

[0100] Step 6: If the surge voltage is not greater than the sum of the conduction voltages of the two discharge tubes G1 and G2, the discharge tube G1 is controlled to be turned on, and the current first flows through the low-frequency channel and then transfers to the high-frequency channel at the PIN3 point.

[0101] In the scheme of the present invention, by Figure 2 The new anti-surge circuit shown can complete the high- and low-frequency channel conversion in a short time, so as to achieve the purpose of filtering out both high and low frequency interference, and can solve the problem of high after-sales failure rate due to the risk of damage to the controller caused by excessive bus voltage. Under different surge voltage conditions, the bus voltage of the air-conditioning outdoor unit controller can be maintained within the tolerable range of the mainboard of the air-conditioning outdoor unit controller (including the withstand voltage range of the mainboard components). By quickly switching between the low-frequency channel and the high-frequency channel in a short time, the entire circuit can respond quickly when facing surge signals of different frequencies, thereby absorbing the peak voltage under lightning surge conditions, ensuring that the bus voltage of the controller is always maintained within the withstand voltage of the mainboard components under various frequency bands, and can largely resist the potential threats brought by lightning surges.

[0102] Since the processing and functions implemented by the method of this embodiment basically correspond to the embodiments, principles and examples of the aforementioned air-conditioner outdoor unit controller and air conditioner, for the details not described in this embodiment, please refer to the relevant descriptions in the aforementioned embodiments and will not be repeated here.

[0103] In summary, it is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0104] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the claims of the present invention.

Claims

1. A protective device for an air conditioner outdoor unit controller, characterized in that: The air conditioner outdoor unit controller has a rectifier bridge; the protection device of the air conditioner outdoor unit controller includes: a sampling unit, a low-frequency discharge unit, a high-frequency absorption unit, and a control unit; the low-frequency discharge unit and the high-frequency absorption unit are connected and are both arranged at the front end of the rectifier bridge; wherein, The sampling unit is used to sample the surge voltage from the AC power input side of the front end of the rectifier bridge, and record it as the surge voltage of the front end of the rectifier bridge; The control unit is used to control the on or off of the low-frequency discharge unit according to the surge voltage at the front end of the rectifier bridge; The low-frequency discharge unit is used to filter out the low-frequency interference in the surge voltage at the front end of the rectifier bridge when the low-frequency discharge unit itself is turned on, so as to obtain a first filtered voltage at the front end of the rectifier bridge; The high-frequency absorption unit is used to filter out the high-frequency interference in the first filtered voltage at the front end of the rectifier bridge when the low-frequency discharge unit is turned on, so as to obtain the second filtered voltage at the front end of the rectifier bridge; When the low-frequency discharge unit is not turned on, high-frequency interference in the surge voltage at the front end of the rectifier bridge is filtered out to obtain a third filtered voltage at the front end of the rectifier bridge.

2. The protection device for the air conditioner outdoor unit controller according to claim 1, characterized in that: The low-frequency discharge unit includes: a first discharge module; the high-frequency absorption unit includes: a first RC module; wherein, The input end of the first discharge module is used to receive the surge voltage at the front end of the rectifier bridge; the output end of the first discharge module is connected to the input end of the first RC module; the output end of the first RC module is connected to the front end of the rectifier bridge.

3. The protection device for the air conditioner outdoor unit controller according to claim 2, characterized in that: The low-frequency discharge unit further includes: a second discharge module; wherein: The output end of the first discharge module is also connected to the input end of the second discharge module; the output end of the second discharge module is connected to the front end of the rectifier bridge.

4. The protection device for the air conditioner outdoor unit controller according to claim 2 or 3, characterized in that: The high-frequency absorption unit further includes: a second RC module; wherein, The input end of the first discharge module is also connected to the input end of the second RC module; the output end of the second RC module is connected to the input end of the first RC module; Wherein, when the low-frequency discharge unit further includes a second discharge module, the first discharge module is connected in parallel with the second RC module, and the second discharge module is connected in parallel with the first RC module; and a turn-on voltage of the first discharge module is the same as a turn-on voltage of the second discharge module.

5. The protection device for the air conditioner outdoor unit controller according to claim 4, characterized in that: The first RC module includes: a first resistor and a first capacitor; the second RC module includes: a second resistor and a second capacitor; the resistance of the first resistor is greater than the resistance of the second resistor; wherein, The output end of the first discharge module is connected to the first connection end of the first resistor; the second connection end of the first resistor is connected to the first connection end of the first capacitor; the second connection end of the first capacitor, as the output end of the first RC module, is connected to the front end of the rectifier bridge; The input end of the first discharge module is also connected to the first connection end of the second resistor; the second connection end of the second resistor is connected to the first connection end of the second capacitor; and the second connection end of the second capacitor is connected to the first connection end of the first resistor.

6. The protection device for the air conditioner outdoor unit controller according to any one of claims 1 to 5, characterized in that: In the case where the low-frequency discharge unit includes a first discharge module and a second discharge module, and the high-frequency absorption unit includes a first RC module and a second RC module, the control unit controls the on or off of the low-frequency discharge unit according to the magnitude of the surge voltage at the front end of the rectifier bridge, including: Determine whether the surge voltage at the front end of the rectifier bridge is greater than the turn-on voltage of a single discharge module in the first discharge module and the second discharge module; If it is determined that the surge voltage at the front end of the rectifier bridge is not greater than the turn-on voltage of a single discharge module in the first discharge module and the second discharge module, control the first discharge module and the second discharge module to be turned off; If it is determined that the surge voltage at the front end of the rectifier bridge is greater than the on-voltage of a single discharge module in the first discharge module and the second discharge module, then determine whether the surge voltage at the front end of the rectifier bridge is greater than the sum of the on-voltages of the two discharge modules in the first discharge module and the second discharge module; If it is determined that the surge voltage at the front end of the rectifier bridge is greater than the sum of the conduction voltages of the two discharge modules in the first discharge module and the second discharge module, then the first discharge module and the second discharge module are controlled to be turned on; If it is determined that the surge voltage at the front end of the rectifier bridge is not greater than the sum of the on-state voltages of the first discharge module and the second discharge module, the first discharge module is controlled to be turned on, and the second discharge module is controlled to be turned off.

7. An air conditioner outdoor unit controller, characterized in that: include: A protective device for an air conditioner outdoor unit controller as claimed in any one of claims 1 to 6.

8. An air conditioner, characterized in that: include: A protective device for an air conditioner outdoor unit controller as claimed in any one of claims 1 to 6, or an air conditioner outdoor unit controller as claimed in claim 7.

9. A method for protecting an air conditioner outdoor unit controller corresponding to the protection device for the air conditioner outdoor unit controller according to any one of claims 1 to 6, characterized in that: include: Sampling a surge voltage from the AC power input side of the front end of the rectifier bridge, and recording it as the surge voltage of the front end of the rectifier bridge; Controlling the on or off of the low-frequency discharge unit according to the size of the surge voltage at the front end of the rectifier bridge; Wherein, the low-frequency discharge unit, when turned on, filters out the low-frequency interference in the surge voltage at the front end of the rectifier bridge to obtain a first filtered voltage at the front end of the rectifier bridge; By means of the high-frequency absorption unit, when the low-frequency discharge unit is turned on, high-frequency interference in the first filtered voltage at the front end of the rectifier bridge is filtered out to obtain a second filtered voltage at the front end of the rectifier bridge; By means of the high-frequency absorption unit, when the low-frequency discharge unit is not turned on, the high-frequency interference in the surge voltage at the front end of the rectifier bridge is filtered out to obtain a third filtered voltage at the front end of the rectifier bridge.

10. The method for protecting the controller of the outdoor unit of the air conditioner according to claim 9, characterized in that: In the case where the low-frequency discharge unit includes a first discharge module and a second discharge module, and the high-frequency absorption unit includes a first RC module and a second RC module, controlling the on or off of the low-frequency discharge unit according to the size of the surge voltage at the front end of the rectifier bridge includes: Determine whether the surge voltage at the front end of the rectifier bridge is greater than the turn-on voltage of a single discharge module in the first discharge module and the second discharge module; If it is determined that the surge voltage at the front end of the rectifier bridge is not greater than the turn-on voltage of a single discharge module in the first discharge module and the second discharge module, control the first discharge module and the second discharge module to be turned off; If it is determined that the surge voltage at the front end of the rectifier bridge is greater than the on-voltage of a single discharge module in the first discharge module and the second discharge module, then determine whether the surge voltage at the front end of the rectifier bridge is greater than the sum of the on-voltages of the two discharge modules in the first discharge module and the second discharge module; If it is determined that the surge voltage at the front end of the rectifier bridge is greater than the sum of the conduction voltages of the two discharge modules in the first discharge module and the second discharge module, then the first discharge module and the second discharge module are controlled to be turned on; If it is determined that the surge voltage at the front end of the rectifier bridge is not greater than the sum of the on-state voltages of the first discharge module and the second discharge module, the first discharge module is controlled to be turned on, and the second discharge module is controlled to be turned off.

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