Protection circuit, compressor and air conditioner

Abstract

The utility model provides a protection circuit, a compressor and an air conditioner. The protection circuit comprises a resistor R5 located on a bus; the charging loop is connected with the resistor R5, and a working module is arranged on the charging loop; the working module has a charging state, and when the working module is in the charging state, the current on the charging loop flows through the resistor R5; the control part is used for controlling on and off of a circuit where the resistor R5 is located; and the detection module is used for detecting the voltage of the bus, the detection module is in signal connection with the control part so as to control the control part to switch on or switch off the bus according to the voltage on the bus, and the protection circuit solves the technical problem that the cement resistor on the compressor is easy to damage.

Description

Technical Field

[0001] The utility model relates to the technical field of compressors, in particular to a protection circuit, a compressor and an air conditioner. Background Art

[0002] In commercial air-conditioning units, the charging logic of the compressor drive bus charging circuit is generally to charge the main circuit through a cement resistor when power is turned on. When the bus voltage is detected to be greater than the preset voltage value, the second relay K2 that short-circuits the cement resistor is energized to reduce losses.

[0003] However, due to abnormal conditions such as debugging control or logic control, the fan IPM module may continue to work after the second relay K2 is disconnected when the compressor stops, forming a current loop, thereby overloading the cement resistor on the charging circuit, causing damage to the cement resistor and the driver board to fail to work normally. Utility Model Content

[0004] The purpose of the present invention is to overcome the above technical deficiencies and provide a protection circuit, a compressor and an air conditioner to solve the technical problem in the related art that the cement resistor on the compressor is easily damaged.

[0005] In order to achieve the above technical objectives, the present invention adopts the following technical solutions: providing a protection circuit, including:

[0006] Resistor R5 located on the busbar;

[0007] a charging circuit connected to the resistor R5, wherein a working module is provided on the charging circuit; the working module has a charging state, and when the working module is in the charging state, the current on the charging circuit flows through the resistor R5;

[0008] A control component, the control component is used to control the on and off of the circuit where the resistor R5 is located;

[0009] A detection module is used to detect the voltage of the busbar. The detection module is connected to the control component signal to control the control component to turn on or off the busbar according to the voltage on the busbar.

[0010] Furthermore, the detection module includes:

[0011] A comparator U1, used to drive the control component;

[0012] A detection circuit, one end of the detection circuit is connected to the bus, and the other end of the detection circuit is connected to the positive input end of the comparator U1.

[0013] Furthermore, the detection module further includes:

[0014] A comparison circuit, one end of which is connected to an input voltage, the other end of which is connected to an inverting input end of the comparator, and a resistor R3 is provided on the comparison circuit.

[0015] Furthermore, the detection module further includes a resistor R6, and the resistor R6 is connected in parallel with the resistor R3.

[0016] Furthermore,

[0017] The detection circuit is provided with a resistor R4; and / or,

[0018] One end of the resistor R6 is connected to the comparison circuit, and the other end of the resistor R6 is grounded; and / or,

[0019] The control component is a first relay K1 provided on the busbar.

[0020] Furthermore, the detection module includes a transistor Q1 , the base of the transistor Q1 is connected to the output end of the comparator U1 , and the transistor Q1 is used to turn on or off the circuit that controls the detection module.

[0021] Furthermore, the protection circuit includes:

[0022] A control circuit, wherein the control circuit is provided with a second relay K2 connected in parallel with the resistor R5;

[0023] A control module is connected to the second relay K2 by signal to control the second relay K2 to connect or disconnect the control circuit.

[0024] Furthermore, a first voltage threshold is set in the control module, and when the voltage value across the resistor R5 is greater than or equal to the first voltage threshold, the second relay K2 is energized; a second voltage threshold is set in the detection module, and when the voltage value across the R5 is greater than or equal to the second voltage threshold, the control component is turned on or the bus; wherein the first voltage threshold is less than the second voltage threshold.

[0025] A compressor includes a protection circuit, wherein the protection circuit is the above-mentioned protection circuit.

[0026] Furthermore, the compressor comprises:

[0027] A charging circuit, wherein a capacitor C2 is provided on the charging circuit and the capacitor C2 is connected to the bus;

[0028] A working module, the working module is connected to the capacitor C2; the working module is a fan driving module for driving a fan.

[0029] An air conditioner includes a protection circuit, wherein the protection circuit is the above-mentioned protection circuit.

[0030] Beneficial effects:

[0031] The present invention provides a protection circuit comprising: a resistor R5 located on a busbar; a charging circuit connected to the resistor R5, with a working module disposed on the charging circuit; the working module having a charging state. When the working module is in the charging state, current in the charging circuit flows through the resistor R5; a control component for controlling the on / off state of the circuit in which the resistor R5 is located; and a detection module for detecting the voltage of the busbar. The detection module is signal-connected to the control component to control the control component to turn the busbar on or off based on the voltage on the busbar. When the busbar is off, the working module may continue to operate, thereby generating current in the charging circuit. This current flows through the resistor R5 and may burn out the resistor. With this configuration, a control component for controlling the on / off state of the busbar is disposed in the circuit in which the resistor R5 is located. The detection module detects the voltage on the busbar. When the voltage is too high, the control component shuts off the charging circuit, thereby preventing excessive voltage across the resistor R5 and protecting the resistor R5. This solves the technical problem of easily damaged cement resistors in compressors. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural diagram of the protection circuit adopted in the embodiment of the present utility model;

[0033] Figure 2 Schematic diagram of the structure of the detection module of the protection circuit used in the embodiment of the present utility model;

[0034] Figure 3 This is a schematic structural diagram of an embodiment of a control component of a protection circuit used in an embodiment of the present utility model;

[0035] Figure 4 It is a structural diagram of another embodiment of the control component used in the embodiment of the present utility model;

[0036] Figure 5 This is a control flow chart of an embodiment of the protection circuit used in the embodiment of the present utility model;

[0037] Figure 6 This is a control flow chart of another embodiment of the protection circuit adopted in the embodiment of the present utility model.

[0038] The above drawings include the following reference numerals:

[0039] 1. Busbar; 2. Detection module; 21. Detection circuit; 22. Comparison circuit; 3. Control circuit; 4. Control module; 5. Charging circuit; 6. Working module. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0041] See also Figures 1 to 4 According to an embodiment of the present invention, a protection circuit is provided, comprising: a resistor R5 located on a bus 1; a charging circuit connected to the resistor R5, and a working module 6 provided on the charging circuit; the working module 6 has a charging state, and when the working module 6 is in the charging state, the current on the charging circuit flows through the resistor R5; a control component, the control component being used to control the on / off of the circuit in which the resistor R5 is located; a detection module 2, the detection module 2 being used to detect the voltage of the bus 1, the detection module 2 being signal-connected to the control component to control the control component to turn on or off the bus 1 according to the voltage on the bus 1.

[0042] When busbar 1 is shut off, operating module 6 may continue to operate, thereby generating a current in the charging circuit. This current flows through resistor R5, potentially burning out resistor R5. With this configuration, a control component for controlling the on / off state of busbar 1 is provided in the circuit where resistor R5 resides. Detection module 2 detects the voltage on busbar 1. When the voltage is too high, the control component shuts off the charging circuit, thereby preventing excessive voltage across resistor R5 and protecting it. This resolves the technical issue of easily damaged cement resistors in compressors.

[0043] See also Figure 1 、 Figure 2 In the protection circuit of this embodiment, the detection module 2 includes: a comparator U1, which is used to drive the control component; a detection circuit 21, one end of the detection circuit 21 is connected to the bus 1, and the other end of the detection circuit 21 is connected to the positive input end of the comparator U1.

[0044] Specifically, the control component is a relay K1. A first relay K1 is connected in series next to the cement resistor R5. The comparator U1 detects the relationship between the bus voltage and the preset voltage value, and controls the relay connected in series with the cement resistor to be closed or disconnected, thereby controlling the cement resistor to be connected in and out of the charging circuit.

[0045] In the protection circuit of this embodiment, see Figure 1 The detection module 2 further includes: a comparison circuit 22, one end of the comparison circuit 22 is connected to the input voltage 23, the other end of the comparison circuit 22 is connected to the inverting input end of the comparator U1, and a resistor R3 is provided on the comparison circuit 22.

[0046] In this way, an input voltage 23 is used to provide a comparison value for the comparator U1, so that the detection module 2 can judge the magnitude of the bus 1 voltage, which is convenient for control.

[0047] See also Figure 1 In the protection circuit of this embodiment, the detection module 2 further includes a resistor R6, and the resistor R6 is connected in parallel with the resistor R3.

[0048] In this way, the comparison resistance value can be conveniently adjusted through the resistor R3 and the resistor R6, thereby meeting the requirements of different voltage value controls.

[0049] In the protection circuit of this embodiment, see Figure 1 , a resistor R4 is provided on the detection circuit 21; and / or, one end of the resistor R6 is connected to the comparison circuit 22, and the other end of the resistor R6 is grounded; and / or, the control component is a first relay K1 provided on the bus 1.

[0050] With the above arrangement, the voltage input to the comparator U1 can be adjusted through R4, thereby protecting the comparator U1.

[0051] In the protection circuit of this embodiment, see Figure 1 、 Figure 2 The detection module 2 includes a transistor Q1 , the base of which is connected to the output end of the comparator U1 , and the transistor Q1 is used to turn on or off the circuit that controls the detection module 2 .

[0052] In this way, by providing the transistor Q1, the signal output by the comparator U1 can accurately control the control component, thereby effectively ensuring the safety of the resistor R5.

[0053] In the protection circuit of this embodiment, see Figure 1 、 Figure 2 The protection circuit includes: a control circuit 3, on which a second relay K2 connected in parallel with the resistor R5 is provided; a control module 4, which is signal-connected to the second relay K2 to control the second relay K2 to connect or disconnect the control circuit 3.

[0054] With the above arrangement, by providing a protection circuit and short-circuiting the resistor R5, the resistor R5 is protected. Thus, different control strategies can be selected according to different situations to control the resistor R5, thereby enriching the function of the protection structure.

[0055] In the protection circuit of this embodiment, see Figure 1 、 Figure 2 A first voltage threshold is set in the control module 4. When the voltage value across the resistor R5 is greater than or equal to the first voltage threshold, the second relay K2 is energized. A second voltage threshold is set in the detection module 2. When the voltage value across the resistor R5 is greater than or equal to the second voltage threshold, the control component turns on the bus 1. The first voltage threshold is less than the second voltage threshold.

[0056] With the above arrangement, when the bus 1 voltage is greater than the preset voltage value of the second relay K2 that shorts the resistor R5, the MCU first controls the second relay K2 to close. At the same time, when the comparator U1 detects that the bus 1 voltage is greater than the preset voltage protection value (there is a certain threshold between this voltage protection value and the preset voltage value for K2 to close, thereby controlling the second relay K2 to close before the first relay K1), the first relay K1 is disconnected, thereby disconnecting the resistor R5.

[0057] For example, for a three-phase 540V voltage, the software usually determines that K2 is energized at 380V, and the energizing threshold of K1 can be set to 400V through the hardware circuit.

[0058] The compressor of this embodiment includes a protection circuit, and the protection circuit is the protection circuit mentioned above.

[0059] Specifically, the compressor of this embodiment adopts the above-mentioned protection circuit, and a control component for controlling the on and off of the bus 1 is provided in the circuit where the resistor R5 is located. The voltage on the bus 1 is detected by the detection module 2. When the voltage is too high, the control component shuts off the charging circuit, thereby avoiding excessive voltage at both ends of the resistor R5, protecting the resistor R5, and solving the technical problem that the cement resistor on the compressor is easily damaged.

[0060] In the compressor of this embodiment, see Figure 1 The compressor includes: a charging circuit 5, on which a capacitor C2 is provided, and the capacitor C2 is connected to the bus 1; and a working module 6, which is connected to the capacitor C2.

[0061] Specifically, due to abnormal conditions such as debugging control or logic control, the fan IPM module may continue to work after the second relay K2 is disconnected when the compressor stops, forming a current loop, thereby overloading the cement resistor on the charging circuit, causing damage to the cement resistor and the driver board to fail to work normally.

[0062] The air conditioner of this embodiment includes a protection circuit, which is the protection circuit mentioned above.

[0063] The protection circuit of this embodiment is described as follows:

[0064] In commercial air conditioning units, the typical charging logic for the compressor drive bus charging circuit is to charge the main circuit via a cement resistor upon power-up. When the bus voltage is detected to be greater than a preset value, the second relay K2 is activated, shorting the cement resistor to reduce losses. However, due to abnormalities in commissioning control or logic control, it is possible that when the compressor is shut down, the second relay K2 disconnects while the fan IPM module continues to operate, creating a current loop that overloads the cement resistor in the charging circuit, damaging it and causing the driver board to malfunction.

[0065] To address the above-mentioned issues, the present invention proposes a method for protecting cement resistors from overload in a charging circuit. The main implementation method involves connecting a first relay K1 in series with the cement resistor. A comparator detects the relationship between the bus voltage and a preset voltage value, controlling the closing and opening of the relay connected in series with the cement resistor, thereby controlling the cement resistor's connection and disconnection from the charging circuit. When the bus voltage is detected to be less than the preset protection voltage value, the comparator outputs a low level, closing the first relay K1 connected in series with the cement resistor, connecting the cement resistor to the charging circuit for charging. When the bus voltage is greater than the preset voltage value of the second relay K2, which shorts the cement resistor, the MCU first controls the second relay K2 to close. Simultaneously, when the comparator detects that the bus voltage is greater than the preset voltage protection value (there is a certain threshold between this voltage protection value and the preset voltage value at which K2 closes, thereby controlling the second relay K2 to close before the first relay K1), the first relay K1 opens, disconnecting the cement resistor. This ensures normal charging function and, after the second relay K2 opens, if overcharging occurs, the first relay K1 disconnects the cement resistor, thus preventing damage to the cement resistor.

[0066] Example 1:

[0067] See also Figure 3 、 Figure 5 A first relay K1 is connected in series with the cement resistor. A comparator detects the relationship between the bus voltage and a preset voltage value, controlling the closing and opening of the relay connected in series with the cement resistor, thereby controlling the cement resistor's connection and disconnection from the charging circuit. When the bus voltage is detected to be less than the preset protection voltage, the comparator outputs a low level, closing the first relay K1 connected in series with the cement resistor, connecting the cement resistor to the charging circuit for charging. At this time, comparator U1 detects the voltage of bus 1. If the voltage does not exceed the preset voltage protection value, it indicates that resistor R5 will not burn out, and the first relay K1 does not operate.

[0068] Example 2:

[0069] See also Figure 4 、 Figure 5 A first relay K1 is connected in series with the cement resistor. A comparator detects the relationship between the bus voltage and a preset voltage value, controlling the closing and opening of the relay connected in series with the cement resistor, thereby controlling the cement resistor's connection and disconnection from the charging circuit. When the bus voltage is detected to be lower than the preset protection voltage, the comparator outputs a low level, closing the first relay K1 connected in series with the cement resistor, connecting the cement resistor to the charging circuit for charging. At this point, comparator U1 detects the voltage of bus 1. When the voltage reaches the preset protection voltage, indicating that resistor R5 may be burned out, the first relay K1 disconnects bus 1, protecting resistor R5.

[0070] Example 3:

[0071] See also Figure 6 , a first relay K1 is connected in series next to the cement resistor, and the relationship between the bus voltage and the preset voltage value is detected by the comparator, which controls the relay connected in series with the cement resistor to be closed and disconnected, thereby controlling the cement resistor to be connected and disconnected from the charging circuit. When it is detected that the bus voltage is lower than the preset protection voltage value, the comparator outputs a low level, and the first relay K1 connected in series with the cement resistor is closed, connecting the cement resistor to the charging circuit for charging. When the bus voltage is greater than the preset voltage value of the second relay K2 that short-circuits the cement resistor, the MCU first controls the second relay K2 to be closed. At the same time, when the comparator detects that the bus voltage is greater than the preset voltage protection value (there is a certain threshold between this voltage protection value and the preset voltage value for K2 to be closed, thereby controlling the second relay K2 to be closed before the first relay K1), the first relay K1 is disconnected, thereby disconnecting the cement resistor.

[0072] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in a sequence other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0073] Optionally, the specific examples in this embodiment may refer to the examples described in the above embodiments, and this embodiment will not be described in detail here.

[0074] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0075] In the above embodiments of the present application, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0076] The above is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A protection circuit, characterized in that: include: Resistor R5 located on busbar (1); A charging circuit is connected to the resistor R5, and a working module (6) is provided on the charging circuit; the working module (6) has a charging state, and when the working module (6) is in the charging state, the current on the charging circuit flows through the resistor R5; A control component, the control component is used to control the on and off of the circuit where the resistor R5 is located; A detection module (2) is used to detect the voltage of the busbar (1); the detection module (2) is connected to the control component signal to control the control component to turn on or off the busbar (1) according to the voltage on the busbar (1).

2. The protection circuit according to claim 1, wherein: The detection module (2) comprises: A comparator U1, used to drive the control component; A detection circuit (21), one end of the detection circuit (21) is connected to the bus (1), and the other end of the detection circuit (21) is connected to the positive input end of the comparator U1.

3. The protection circuit according to claim 2, wherein: The detection module (2) further comprises: A comparison circuit (22), one end of the comparison circuit (22) is connected to an input voltage (23), the other end of the comparison circuit (22) is connected to an inverting input end of the comparator, and a resistor R3 is provided on the comparison circuit (22).

4. The protection circuit according to claim 3, wherein: The detection module (2) further comprises a resistor R6, and the resistor R6 is connected in parallel with the resistor R3.

5. The protection circuit according to claim 4, characterized in that: The detection circuit (21) is provided with a resistor R4; and / or, One end of the resistor R6 is connected to the comparison circuit (22), and the other end of the resistor R6 is grounded; and / or, The control component is a first relay K1 arranged on the busbar (1).

6. The protection circuit according to claim 2, wherein: The detection module (2) comprises a transistor Q1, the base of which is connected to the output end of the comparator U1, and the transistor Q1 is used to turn on or off the circuit that controls the detection module (2).

7. The protection circuit according to claim 1, wherein: The protection circuit comprises: A control circuit (3), wherein the control circuit (3) is provided with a second relay K2 connected in parallel with the resistor R5; A control module (4) is connected to the second relay K2 via a signal to control the second relay K2 to connect or disconnect the control circuit (3).

8. The protection circuit according to claim 7, wherein: A first voltage threshold is provided in the control module (4), and when the voltage value across the resistor R5 is greater than or equal to the first voltage threshold, the second relay K2 is energized; a second voltage threshold is provided in the detection module (2), and when the voltage value across the resistor R5 is greater than or equal to the second voltage threshold, the control component is turned on or the bus (1); wherein the first voltage threshold is less than the second voltage threshold.

9. A compressor comprising a protection circuit, characterized in that: The protection circuit is the protection circuit according to any one of claims 1 to 8.

10. The compressor according to claim 9, characterized in that The compressor comprises: A charging circuit (5), wherein the charging circuit (5) is provided with a capacitor C2, and the capacitor C2 is connected to the busbar (1); A working module (6), the working module (6) is connected to the capacitor C2; the working module (6) is a fan driving module for driving a fan.

11. An air conditioner comprising a protection circuit, characterized in that: The protection circuit is the protection circuit according to any one of claims 1 to 8.

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