Magnetic suspension compressor, control method and device thereof, storage medium and program product

Abstract

The invention discloses a magnetic suspension compressor and a control method and device thereof, a storage medium and a computer program product, and the method comprises the steps: controlling a selection switch module after receiving a starting instruction, so as to enable a power amplifier module to be connected with a resistor module or the power amplifier module to be connected with a magnetic bearing coil; under the condition that the power amplifier module is connected with the resistor module or the power amplifier module is connected with the magnetic bearing coil, the bearing controller outputs a driving signal to the power amplifier module; acquiring the current detected by the current detection module under the condition that the power amplifier module outputs the driving signal; and according to the current detected by the current detection module, whether the current detection module and the magnetic bearing coil break down or not is determined in stages, so that the magnetic suspension compressor is controlled to be started under the condition that it is determined that neither the current detection module nor the magnetic bearing coil breaks down. According to the scheme, fault detection is carried out on the magnetic bearing and the current detection module before the magnetic suspension compressor is started, and current output is closed in time when faults occur, so that safe starting and operation of the compressor are guaranteed.

Description

Technical Field

[0001] This invention belongs to the field of magnetic levitation compressor technology, specifically relating to a control method, device, magnetic levitation compressor, storage medium, and computer program product for a magnetic levitation compressor, and particularly to a control method, device, magnetic levitation compressor, storage medium, and computer program product for an automatic fault detection device for magnetic bearing coil and current sensor in a magnetic levitation compressor. Background Technology

[0002] A magnetic levitation compressor is a high-efficiency and energy-saving device based on magnetic levitation bearing technology. It uses a magnetic field to levitate the rotor and stator without contact, eliminating mechanical friction and significantly improving energy efficiency, reducing noise, and lowering maintenance costs. Magnetic levitation technology utilizes the principle of "like poles repel, unlike poles attract" in magnetic fields, using an electromagnetic field to levitate and balance the rotor. This eliminates the need for mechanical contact or a lubrication system, reducing frictional losses and avoiding the energy waste and oil contamination problems caused by mechanical friction in traditional compressors.

[0003] The core component of a magnetic levitation compressor is its bearing control system. This system (i.e., the magnetic levitation bearing control system) mainly consists of magnetic bearings, a bearing controller, displacement sensors, and a rotor. The bearing controller collects the rotor's position signal through the displacement sensors and calculates the output control current to the magnetic bearings. The magnetic bearings then generate electromagnetic force, thereby controlling the rotor's levitation. While magnetic levitation compressors operate without oil or friction, their lifespan is limited. During operation, magnetic bearing damage is possible; if the magnetic bearings fail, the compressor will cease operation, and short circuits could lead to electric shocks or other personal injury.

[0004] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The purpose of this invention is to provide a control method, device, magnetic levitation compressor, storage medium, and computer program product for a magnetic levitation compressor. This invention addresses the problem that if the magnetic bearing is damaged during the operation of a magnetic levitation compressor, the compressor will fail to operate, and may even cause electric shock or other personal injury due to short circuit. The invention achieves the effect of ensuring the safe start-up and operation of the compressor by detecting faults in the magnetic bearing and current detection module before starting the magnetic levitation compressor and promptly shutting off the current output when a fault occurs.

[0006] This invention provides a control method for a magnetic levitation compressor. The magnetic levitation compressor includes a bearing controller, a power amplifier module, a magnetic bearing coil, and a current detection module. A selection switch module is provided between the power amplifier module and the magnetic bearing coil, and a resistor module is provided at the magnetic bearing coil. The selection switch module can select whether the resistor module or the magnetic bearing coil is connected to the power amplifier module. The control method for the magnetic levitation compressor includes: upon receiving a start command for the magnetic levitation compressor, controlling the selection switch module to connect the power amplifier module to the resistor module or to the magnetic bearing coil; when the power amplifier module is connected to the resistor module or to the magnetic bearing coil, causing the bearing controller to output a drive signal to the power amplifier module; when the bearing controller outputs a drive signal to the power amplifier module, acquiring the current detected by the current detection module; and based on the current detected by the current detection module, determining in stages whether the current detection module and the magnetic bearing coil are faulty, so that if it is determined that neither the current detection module nor the magnetic bearing coil is faulty, the magnetic levitation compressor is started.

[0007] In some embodiments, controlling the selection switch module to connect the power amplifier module to the resistor module or to the magnetic bearing coil includes: first controlling the selection switch module to connect the power amplifier module to the resistor module; and then, after determining that the current detection module is not faulty, controlling the selection switch module to connect the power amplifier module to the magnetic bearing coil. And / or, the selection switch module has a control terminal, a first connection terminal, and a second connection terminal; the power amplifier module is connected to the control terminal of the selection switch module, the first connection terminal of the selection switch module is connected to the first connection terminal of the resistor module, the second connection terminal of the selection switch module is connected to the first connection terminal of the magnetic bearing coil, and the second connection terminal of the resistor module is connected to the second connection terminal of the magnetic bearing coil; controlling the selection switch module to connect the power amplifier module to the resistor module or to the magnetic bearing coil further includes: controlling the control terminal of the selection switch module to connect to the first connection terminal of the selection switch module to connect the power amplifier module to the resistor module; and, if it is determined that the current detection module is not faulty, then controlling the control terminal of the selection switch module to connect to the second connection terminal of the selection switch module to connect the power amplifier module to the magnetic bearing coil.

[0008] In some embodiments, when the power amplifier module is connected to the resistor module or the power amplifier module is connected to the magnetic bearing coil, the bearing controller outputs a drive signal to the power amplifier module, including: when the power amplifier module is connected to the resistor module, the bearing controller outputs a drive signal required by a preset current threshold within a preset current range to the power amplifier module; when the power amplifier module is connected to the magnetic bearing coil, the bearing controller outputs a drive signal required by any current from a first preset current to an nth preset current within a preset current range to the power amplifier module, where n is a positive integer; wherein, when n is greater than or equal to 2, the nth preset current is greater than the second preset current.

[0009] In some implementations, when the power amplifier module and the resistor module are connected, the current detected by the current detection module is recorded as the current of the resistor module; when the power amplifier module and the magnetic bearing coil are connected, the current detected by the current detection module is recorded as the current of the magnetic bearing coil; based on the current detected by the current detection module, it is determined in stages whether the current detection module and the magnetic bearing coil are faulty, so that if it is determined that neither the current detection module nor the magnetic bearing coil is faulty, the magnetic levitation compressor is controlled to start, including: First stage: when the power amplifier module and the resistor module are connected, after the bearing controller outputs the drive signal required by the preset current threshold within the preset current range to the power amplifier module, based on the current detected by the resistor module, the current is recorded as the current of the magnetic bearing coil. In the first stage, if the current detection module is determined to be faulty, and if it is determined to be faulty, the bearing controller stops outputting drive signals to the power amplifier module and initiates a faulty reminder message for the current detection module. In the second stage, if the current detection module is determined to be not faulty, and with the power amplifier module connected to the magnetic bearing coil, after the bearing controller outputs a drive signal required for any current from the first preset current to the nth preset current within the preset current range to the power amplifier module, the magnetic bearing coil is determined to be faulty based on its current. If the magnetic bearing coil is determined to be faulty, the bearing controller stops outputting drive signals to the power amplifier module and initiates a faulty reminder message for the magnetic bearing coil. If the magnetic bearing coils are determined to be not faulty, the magnetic levitation compressor is controlled to start.

[0010] In some implementations, after the bearing controller outputs the drive signal required for a preset current threshold within a preset current range to the power amplifier module, determining whether the current detection module is faulty based on the current of the resistor module includes: after the bearing controller outputs the drive signal required for a preset current threshold within a preset current range to the power amplifier module, determining whether the current of the resistor module is equal to the preset current threshold; if it is determined that the current of the resistor module is equal to the preset current threshold, then it is determined that the current detection module is not faulty; if it is determined that the current of the resistor module is not equal to the preset current threshold, then it is determined that the current detection module is faulty. And / or, after the bearing controller outputs the drive signal required for a first preset current within a preset current range to the power amplifier module, the current of the magnetic bearing coil obtained is recorded as the first current of the magnetic bearing coil; after the bearing controller outputs the drive signal required for a second preset current within a preset current range to the power amplifier module, the current of the magnetic bearing coil obtained is recorded as the second current of the magnetic bearing coil; and so on, after the bearing controller outputs the drive signal required for the nth preset current within a preset current range to the power amplifier module, the current of the magnetic bearing coil obtained is recorded as the nth current of the magnetic bearing coil; after the bearing controller outputs the drive signal required for any current from the first preset current to the nth preset current within a preset current range to the power amplifier module, the current of the magnetic bearing coil is determined according to the current of the magnetic bearing coil. The determination of whether a fault exists includes: after the bearing controller outputs the drive signal required by the first preset current within the preset current range to the power amplifier module, determining whether the first current of the magnetic bearing coil is equal to 0; if the first current of the magnetic bearing coil is determined to be equal to 0, then the magnetic bearing coil is determined to be faulty and is an open circuit fault; if the first current of the magnetic bearing coil is determined to be not equal to 0, then determining whether the first current of the magnetic bearing coil is equal to the first preset current; if the first current of the magnetic bearing coil is determined to be not equal to the first preset current, then the magnetic bearing coil is determined to be faulty; if the first current of the magnetic bearing coil is determined to be equal to the first preset current, then after the bearing controller incrementally outputs the drive signal required by any current among the second preset current and the nth preset current within the preset current range to the power amplifier module, the determination of whether the magnetic bearing coil is faulty continues based on the current of the magnetic bearing coil.

[0011] In some embodiments, after the bearing controller incrementally outputs a drive signal required by any current within a preset current range (second preset current, nth preset current) to the power amplifier module, it continues to determine whether the magnetic bearing coil is faulty based on the current of the magnetic bearing coil. This includes: outputting a drive signal required by the bearing controller to the power amplifier module (second preset current within a preset current range); after the bearing controller outputs the drive signal required by the bearing controller to the power amplifier module (second preset current within a preset current range), determining whether the second current of the magnetic bearing coil is equal to the second preset current; wherein, the second preset current is greater than the first preset current; if it is determined that the second current of the magnetic bearing coil is equal to the second preset current... If the second preset current is found, the magnetic bearing is determined to be not faulty; or, the bearing controller outputs the drive signal required for the nth preset current within the preset current range to the power amplifier module; after the bearing controller outputs the drive signal required for the nth preset current within the preset current range to the power amplifier module, it is determined whether the nth current of the magnetic bearing coil is equal to the nth preset current; wherein, the nth preset current is greater than the second preset current; if it is determined that the nth current of the magnetic bearing coil is equal to the nth preset current, the magnetic bearing is determined to be not faulty; if it is determined that the second current of the magnetic bearing coil is not equal to the second preset current, or if it is determined that the nth current of the magnetic bearing coil is not equal to the nth preset current, the magnetic bearing coil is determined to be faulty.

[0012] In some embodiments, the magnetic levitation compressor further includes a backup current detection module and a backup magnetic bearing coil; the backup current detection module and the current detection module are switchable; the backup magnetic bearing coil and the magnetic bearing coil are switchable; the control method of the magnetic levitation compressor further includes: after determining in stages whether the current detection module and the magnetic bearing coil are faulty based on the current detected by the current detection module, if the current detection module is determined to be faulty, then the current detection module is switched to the backup current detection module; if the magnetic bearing coil is determined to be faulty, then the magnetic bearing coil is switched to the backup magnetic bearing coil; and the magnetic levitation compressor is controlled to start based on the backup current detection module or the current detection module that is not faulty, and the backup magnetic bearing coil or the magnetic bearing coil that is not faulty.

[0013] In conjunction with the above method, another aspect of the present invention provides a control device for a magnetic levitation compressor, the magnetic levitation compressor having a bearing controller, a power amplifier module, a magnetic bearing coil, and a current detection module; a selection switch module is provided between the power amplifier module and the magnetic bearing coil, and a resistor module is provided at the magnetic bearing coil; the selection switch module is capable of selecting whether the resistor module or the magnetic bearing coil is connected to the power amplifier module; the control device for the magnetic levitation compressor includes: a control unit configured to, upon receiving a start command for the magnetic levitation compressor, control the selection switch module to connect the power amplifier module to the resistor module or to connect the power amplifier module to the current detection module. The magnetic bearing coil is connected; the control unit is further configured to, when the power amplifier module is connected to the resistor module or the power amplifier module is connected to the magnetic bearing coil, cause the bearing controller to output a drive signal to the power amplifier module; the acquisition unit is configured to, when the bearing controller outputs a drive signal to the power amplifier module, acquire the current detected by the current detection module; the control unit is further configured to, based on the current detected by the current detection module, determine in stages whether the current detection module and the magnetic bearing coil are faulty, so as to control the magnetic levitation compressor to start if it is determined that neither the current detection module nor the magnetic bearing coil is faulty.

[0014] In some embodiments, the control unit controls the selection switch module to connect the power amplifier module to the resistor module or to the magnetic bearing coil, including: first controlling the selection switch module to connect the power amplifier module to the resistor module; and then, if it is determined that the current detection module is not faulty, controlling the selection switch module to connect the power amplifier module to the magnetic bearing coil. And / or, the selection switch module has a control terminal, a first connection terminal, and a second connection terminal; the power amplifier module is connected to the control terminal of the selection switch module, the first connection terminal of the selection switch module is connected to the first connection terminal of the resistor module, the second connection terminal of the selection switch module is connected to the first connection terminal of the magnetic bearing coil, and the second connection terminal of the resistor module is connected to the second connection terminal of the magnetic bearing coil; the control unit controls the selection switch module to connect the power amplifier module to the resistor module or to the magnetic bearing coil, and further includes: controlling the control terminal of the selection switch module to connect to the first connection terminal of the selection switch module to connect the power amplifier module to the resistor module; and, if it is determined that the current detection module is not faulty, controlling the control terminal of the selection switch module to connect to the second connection terminal of the selection switch module to connect the power amplifier module to the magnetic bearing coil.

[0015] In some embodiments, when the power amplifier module is connected to the resistor module or the power amplifier module is connected to the magnetic bearing coil, the control unit causes the bearing controller to output a drive signal to the power amplifier module, including: when the power amplifier module is connected to the resistor module, causing the bearing controller to output a drive signal required by a preset current threshold within a preset current range to the power amplifier module; when the power amplifier module is connected to the magnetic bearing coil, causing the bearing controller to output a drive signal required by any current from a first preset current to an nth preset current within a preset current range to the power amplifier module, where n is a positive integer; wherein, when n is greater than or equal to 2, the nth preset current is greater than the second preset current.

[0016] In some embodiments, when the power amplifier module and the resistor module are connected, the current detected by the current detection module is recorded as the current of the resistor module; when the power amplifier module and the magnetic bearing coil are connected, the current detected by the current detection module is recorded as the current of the magnetic bearing coil; the control unit determines whether the current detection module and the magnetic bearing coil are faulty in stages based on the current detected by the current detection module, so as to control the magnetic levitation compressor to start when it is determined that neither the current detection module nor the magnetic bearing coil is faulty, including: First stage: when the power amplifier module and the resistor module are connected, after the bearing controller outputs the drive signal required by the preset current threshold within the preset current range to the power amplifier module, the control unit determines whether the current detection module and the magnetic bearing coil are faulty based on the current detected by the resistor module. The first stage: If the current detection module is determined to be faulty, and the current detection module is determined to be faulty, then the bearing controller stops outputting drive signals to the power amplifier module and initiates a faulty reminder message for the current detection module. The second stage: If the current detection module is determined to be normal, then when the power amplifier module and the magnetic bearing coil are connected, after the bearing controller outputs a drive signal required for any current from the first preset current to the nth preset current within a preset current range to the power amplifier module, the magnetic bearing coil's current is used to determine if the magnetic bearing coil is faulty. If the magnetic bearing coil is determined to be faulty, then the bearing controller stops outputting drive signals to the power amplifier module and initiates a faulty reminder message for the magnetic bearing coil. If all magnetic bearing coils are determined to be normal, then the magnetic levitation compressor is controlled to start.

[0017] In some embodiments, after the bearing controller outputs the drive signal required for a preset current threshold within a preset current range to the power amplifier module, the control unit determines whether the current detection module is faulty based on the current of the resistor module. This includes: after the bearing controller outputs the drive signal required for a preset current threshold within a preset current range to the power amplifier module, determining whether the current of the resistor module is equal to the preset current threshold; if it is determined that the current of the resistor module is equal to the preset current threshold, then it is determined that the current detection module is not faulty; if it is determined that the current of the resistor module is not equal to the preset current threshold, then it is determined that the current detection module is faulty. And / or, after the bearing controller outputs the drive signal required for a first preset current within a preset current range to the power amplifier module, the current of the magnetic bearing coil obtained is recorded as the first current of the magnetic bearing coil; after the bearing controller outputs the drive signal required for a second preset current within a preset current range to the power amplifier module, the current of the magnetic bearing coil obtained is recorded as the second current of the magnetic bearing coil; and so on, after the bearing controller outputs the drive signal required for the nth preset current within a preset current range to the power amplifier module, the current of the magnetic bearing coil obtained is recorded as the nth current of the magnetic bearing coil; the control unit, after the bearing controller outputs the drive signal required for any current from the first preset current to the nth preset current within a preset current range to the power amplifier module, determines the magnetic shaft based on the current of the magnetic bearing coil. Determining whether the magnetic bearing coil is faulty includes: after the bearing controller outputs the drive signal required by the first preset current within the preset current range to the power amplifier module, determining whether the first current of the magnetic bearing coil is equal to 0; if the first current of the magnetic bearing coil is determined to be equal to 0, then the magnetic bearing coil is determined to be faulty and is an open circuit fault; if the first current of the magnetic bearing coil is determined to be not equal to 0, then determining whether the first current of the magnetic bearing coil is equal to the first preset current; if the first current of the magnetic bearing coil is determined to be not equal to the first preset current, then the magnetic bearing coil is determined to be faulty; if the first current of the magnetic bearing coil is determined to be equal to the first preset current, then after the bearing controller incrementally outputs the drive signal required by any current among the second preset current and the nth preset current within the preset current range to the power amplifier module, it continues to determine whether the magnetic bearing coil is faulty based on the current of the magnetic bearing coil.

[0018] In some embodiments, after the control unit causes the bearing controller to incrementally output a drive signal required by any current within a preset current range (second preset current, nth preset current) to the power amplifier module, it continues to determine whether the magnetic bearing coil is faulty based on the current of the magnetic bearing coil. This includes: causing the bearing controller to output a drive signal required by the second preset current within a preset current range to the power amplifier module; after the bearing controller outputs the drive signal required by the second preset current within a preset current range to the power amplifier module, determining whether the second current of the magnetic bearing coil is equal to the second preset current; wherein the second preset current is greater than the first preset current; if the second preset current of the magnetic bearing coil is determined to be faulty... If the current equals the second preset current, then the magnetic bearing is determined to be fault-free; or, the bearing controller outputs the drive signal required for the nth preset current within the preset current range to the power amplifier module; after the bearing controller outputs the drive signal required for the nth preset current within the preset current range to the power amplifier module, it is determined whether the nth current of the magnetic bearing coil is equal to the nth preset current; wherein, the nth preset current is greater than the second preset current; if it is determined that the nth current of the magnetic bearing coil is equal to the nth preset current, then the magnetic bearing is determined to be fault-free; if it is determined that the second current of the magnetic bearing coil is not equal to the second preset current, or if it is determined that the nth current of the magnetic bearing coil is not equal to the nth preset current, then the magnetic bearing coil is determined to be faulty.

[0019] In some embodiments, the magnetic levitation compressor further includes a backup current detection module and a backup magnetic bearing coil; the backup current detection module and the current detection module are switchable; the backup magnetic bearing coil and the magnetic bearing coil are switchable; the control device of the magnetic levitation compressor further includes: the control unit is further configured to, after determining in stages whether the current detection module and the magnetic bearing coil are faulty based on the current detected by the current detection module, if the current detection module is determined to be faulty, switch the current detection module to the backup current detection module; if the magnetic bearing coil is determined to be faulty, switch the magnetic bearing coil to the backup magnetic bearing coil; the control unit is further configured to control the magnetic levitation compressor to start based on the backup current detection module or the current detection module that is not faulty, and the backup magnetic bearing coil or the magnetic bearing coil that is not faulty.

[0020] In conjunction with the above-mentioned device, the present invention further provides a magnetic levitation compressor, comprising: the control device for the magnetic levitation compressor described above.

[0021] In conjunction with the above method, the present invention further provides a storage medium comprising a stored program, wherein, when the program is executed, the device containing the storage medium is controlled to perform the steps of the control method for the magnetic levitation compressor described above.

[0022] In conjunction with the above method, the present invention further provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the control method for the magnetic levitation compressor described above.

[0023] Therefore, the solution of this invention, targeting a magnetic levitation compressor, is based on a bearing controller, a power amplifier module (such as a switching power amplifier), a magnetic bearing coil, and a current detection module (such as a current sensor) for detecting the current of the magnetic bearing coil in the magnetic levitation compressor. A resistor module (such as a current-limiting resistor) and a selection switch module (such as a multiplexer) are set up. The power amplifier module is connected to the control terminal of the selection switch module, the first connection terminal of the selection switch module is connected to the first connection terminal of the resistor module, the second connection terminal of the selection switch module is connected to the first connection terminal of the magnetic bearing coil, and the second connection terminal of the resistor module is connected to the second connection terminal of the magnetic bearing coil. Of course, in the magnetic levitation compressor, the output terminal of the bearing controller is connected to the power amplifier... The input terminals of the module are connected, the output terminal of the power amplifier module is connected to the control terminal of the selector switch module, and the second connection terminal of the magnetic bearing coil is connected to the input terminal of the bearing controller after passing through the current detection module. When the magnetic levitation compressor receives a start-up command, the switching mode of the selector switch module is controlled before the magnetic levitation compressor starts up. First, the current detection module is checked for faults. If the current detection module is not faulty, the magnetic bearing coil is checked for faults. Only if the magnetic bearing coil is not faulty is the magnetic levitation compressor allowed to start up. Thus, by performing fault detection on the magnetic bearing and the current detection module before the magnetic levitation compressor starts up, and promptly shutting off the current output in case of a fault, the safe start-up and operation of the compressor is ensured.

[0024] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention.

[0025] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0026] Figure 1 This is a flowchart illustrating an embodiment of the control method for the magnetic levitation compressor of the present invention; Figure 2 This is a flowchart illustrating one embodiment of the method of the present invention for controlling the selection switch module; Figure 3This is a flowchart illustrating an embodiment of the method of the present invention for controlling the terminals of the selection switch module; Figure 4 This is a schematic flowchart of an embodiment of the method of the present invention, which causes the bearing controller to output a drive signal to the power amplifier module. Figure 5 This is a flowchart illustrating an embodiment of the method of the present invention for determining whether the current detection module and the magnetic bearing coil are faulty in stages. Figure 6 This is a flowchart illustrating an embodiment of the method of the present invention for determining whether the current detection module is faulty; Figure 7 This is a flowchart illustrating an embodiment of the method of the present invention for determining whether the magnetic bearing coil is faulty; Figure 8 This is a flowchart illustrating an embodiment of the method of the present invention for further determining whether the magnetic bearing coil is faulty; Figure 9 This is a flowchart illustrating an embodiment of the method of the present invention, which involves switching the backup current detection module and / or switching the backup magnetic bearing coil. Figure 10 This is a schematic diagram of the structure of an embodiment of the control device for the magnetic levitation compressor of the present invention; Figure 11 This is a schematic diagram of the hardware circuit for an automatic fault detection device for magnetic bearing coils and current sensors in a magnetic levitation compressor. Figure 12 This is a flowchart illustrating a current sensor fault detection method. Figure 13 This is a flowchart illustrating a magnetic bearing fault detection method. Figure 14 This is another hardware circuit diagram of an automatic fault detection device for magnetic bearing coils and current sensors in a magnetic levitation compressor.

[0027] Referring to the accompanying drawings, the reference numerals in the embodiments of the present invention are as follows: 102 - Acquisition unit; 104 - Control unit. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0029] Considering that if the magnetic bearing is damaged during the operation of a magnetic levitation compressor, the compressor will fail to operate, and may even cause electric shock or other personal injury due to short circuits. Damage to the magnetic bearing can manifest in various ways, such as aging of the magnetic bearing wiring leading to burnout of the magnetic bearing coil due to high-temperature operation, or corrosion of the magnetic bearing coil connecting components causing a short circuit between the magnetic bearing coil and the casing. These problems not only prevent the compressor from operating but may also lead to electric shock and other personal injury due to short circuits.

[0030] Therefore, in response to the potential damage to magnetic bearings, the present invention proposes a control method for a magnetic levitation compressor. Specifically, it is a control method for an automatic fault detection device for magnetic bearing coils and current sensors in a magnetic levitation compressor. Before starting the magnetic levitation compressor, fault detection and diagnosis are performed on the magnetic bearings and current sensors. If a fault occurs, the current output is shut off in time to avoid further damage to the compressor and the occurrence of safety issues.

[0031] According to an embodiment of the present invention, a control method for a magnetic levitation compressor is provided, such as... Figure 1 The diagram shows a flowchart of an embodiment of the method of the present invention. The magnetic levitation compressor includes a bearing controller, a power amplifier module, a magnetic bearing coil, and a current detection module (i.e., a current detection module for detecting the current of the magnetic bearing coil). A selection switch module is provided between the power amplifier module and the magnetic bearing coil, and a resistor module is provided at the magnetic bearing coil. The selection switch module can select whether the resistor module or the magnetic bearing coil is connected to the power amplifier module. The power amplifier module is, for example, a switching power amplifier (i.e., a power switching transistor in the bearing controller); the current detection module is, for example, a current sensor for detecting the current of the magnetic bearing coil; and the resistor module is, for example, a current-limiting resistor. In the solution of the present invention, as shown... Figure 1 As shown, the control method of the magnetic levitation compressor includes steps S110 to S140.

[0032] In step S110, when the magnetic levitation compressor is powered on and a start command for the magnetic levitation compressor is received, the bearing controller controls the selection switch module to connect the power amplifier module to the resistor module or to connect the power amplifier module to the magnetic bearing coil.

[0033] In step S120, when the power amplifier module is connected to the resistor module or the power amplifier module is connected to the magnetic bearing coil, the bearing controller outputs a drive signal to the power amplifier module to energize the resistor module or the magnetic bearing coil.

[0034] In step S130, when the bearing controller outputs a drive signal to the power amplifier module, the current detected by the current detection module is acquired.

[0035] In step S140, based on the current detected by the current detection module, it is determined in stages whether the current detection module and the magnetic bearing coil are faulty. If it is determined that neither the current detection module nor the magnetic bearing coil is faulty, the magnetic levitation compressor is controlled to start. Specifically: if it is determined that the current detection module and / or the magnetic bearing coil is faulty, the bearing controller stops outputting drive signals to the power amplifier module and initiates a reminder message indicating that the current detection module and / or the magnetic bearing coil is faulty; if it is determined that neither the current detection module nor the magnetic bearing coil is faulty, the magnetic levitation compressor is controlled to start.

[0036] The present invention proposes an automatic fault detection device for magnetic bearing coils and current sensors in a magnetic levitation compressor. This device can detect and diagnose faults in the magnetic bearings and current sensors before the magnetic levitation compressor is started, and promptly shut off the current output when a fault occurs, thereby preventing further damage to the compressor and safety issues.

[0037] In some embodiments, step S110, which causes the bearing controller to control the selection switch module to connect the power amplifier module to the resistor module or to connect the power amplifier module to the magnetic bearing coil, includes: controlling the process of the selection switch module.

[0038] The following is combined with Figure 2 The flowchart shown is a schematic diagram of an embodiment of the method of the present invention for controlling the selection switch module. The specific process of controlling the selection switch module in step S110 is further explained, including steps S210 to S220.

[0039] Step S210: The bearing controller first controls the selection switch module to connect the power amplifier module and the resistor module.

[0040] Step S220: If it is determined that the current detection module is not faulty, the bearing controller controls the selection switch module to connect the power amplifier module to the magnetic bearing coil.

[0041] In the present invention, the bearing controller can drive the switching power amplifier (i.e., the power switching tube in the bearing controller) to work, thereby outputting control current to the current limiting resistor or the magnetic bearing coil. The current signal is collected by the current sensor, and based on the corresponding reference data, it can be analyzed whether the magnetic bearing coil or the current sensor is faulty, and the detection is timely and accurate.

[0042] In some embodiments, the selection switch module has a control terminal, a first connection terminal, and a second connection terminal. The power amplifier module is connected to the control terminal of the selection switch module, the first connection terminal of the selection switch module is connected to the first connection terminal of the resistor module, the second connection terminal of the selection switch module is connected to the first connection terminal of the magnetic bearing coil, and the second connection terminal of the resistor module is connected to the second connection terminal of the magnetic bearing coil. Specifically, a selection switch module and a resistor module are provided at the power amplifier module and the magnetic bearing coil. The output terminal of the power amplifier module is connected to the control terminal of the selection switch module, the first connection terminal of the selection switch module is connected to the first connection terminal of the resistor module, the second connection terminal of the selection switch module is connected to the first connection terminal of the magnetic bearing coil, and the second connection terminal of the resistor module is connected to the second connection terminal of the magnetic bearing coil. Of course, in the magnetic levitation compressor, the output terminal of the bearing controller is connected to the input terminal of the power amplifier module, the output terminal of the power amplifier module is connected to the control terminal of the selection switch module, and the second connection terminal of the magnetic bearing coil is connected to the input terminal of the bearing controller after passing through the current detection module.

[0043] Step S110, which involves the bearing controller controlling the selection switch module to connect the power amplifier module to the resistor module or to the magnetic bearing coil, further includes the process of controlling the terminals of the selection switch module.

[0044] The following is combined with Figure 3 The flowchart shown is a schematic diagram of an embodiment of the method of the present invention for controlling the terminals of the selection switch module. The specific process of controlling the terminals of the selection switch module in step S110 is further explained, including steps S310 to S320.

[0045] Step S310: The bearing controller connects the control terminal of the selection switch module to the first connection terminal of the selection switch module, so that the power amplifier module is connected to the resistor module.

[0046] Step S320: If it is determined that the current detection module is not faulty, the bearing controller controls the control terminal of the selection switch module to connect with the second connection terminal of the selection switch module, so that the power amplifier module is connected to the magnetic bearing coil.

[0047] Figure 11 This is a schematic diagram of the hardware circuit for an automatic fault detection device for the magnetic bearing coil and current sensor in a magnetic levitation compressor. Figure 11The hardware circuit of the automatic fault detection device for the magnetic bearing coil and current sensor in the magnetic levitation compressor shown is as follows: The automatic fault detection device for the magnetic bearing consists of a bearing controller, a memory, a switching power amplifier (i.e., the power switching transistor in the bearing controller), a multiplexer, a current-limiting resistor, a magnetic bearing coil, and a current sensor. The current-limiting resistor, located in the bearing controller, is used to maintain the control loop conduction independently of the magnetic bearing coil and has an overload prevention function. Its function is to assist in troubleshooting whether the current sensor is faulty. Without this loop, it is impossible to determine whether the fault lies with the current sensor or the magnetic bearing coil. The current sensor, also located in the bearing controller, is used to collect the current passing through the magnetic bearing coil, acting as a sampling feedback mechanism to form a closed-loop current control. The multiplexer has a control terminal, a first connection terminal (i.e., terminal 1), and a second connection terminal (i.e., terminal 2). The switching power amplifier (i.e., the power switching transistor in the bearing controller) is placed in front of the magnetic bearing coil. Its function is to pass current through the magnetic bearing coil. The switching power amplifier (i.e., the power switching transistor in the bearing controller) can be the switching transistor in the inverter of the motor controller or the switching transistor in the Intelligent Power Module (IPM). The switching transistor can be an Insulated Gate Bipolar Transistor (IGBT).

[0048] The memory is connected to the bearing controller. The bearing controller outputs a drive signal to the switching power amplifier (i.e., the power switching transistor in the bearing controller). The switching power amplifier (i.e., the power switching transistor in the bearing controller) is connected to the control terminal of the multiplexer. The first connection terminal (i.e., terminal 1) of the multiplexer is connected to the first connection terminal of the current limiting resistor. The second connection terminal (i.e., terminal 2) of the multiplexer is connected to the first connection terminal of the magnetic bearing coil. After the second connection terminal of the current limiting resistor is connected to the second connection terminal of the magnetic bearing coil, it is connected to the bearing controller via the current sensor.

[0049] exist Figure 11 In the example shown, the bearing controller can control the multiplexer to select different paths. When the multiplexer is closed at "1", that is, when the control terminal of the multiplexer is connected to the first connection terminal (i.e., terminal 1) of the multiplexer, the bearing controller forms a path with the current limiting resistor, which can be used for current sensor fault detection. When the multiplexer is closed at "2", that is, when the control terminal of the multiplexer is connected to the second connection terminal (i.e., terminal 2) of the multiplexer, the bearing controller forms a path with the magnetic bearing coil, which can be used for magnetic bearing coil fault detection.

[0050] In the present invention, the bearing controller can drive the switching power amplifier (i.e., the power switching transistor in the bearing controller) to work, thereby outputting control current to the current limiting resistor or the magnetic bearing coil. The current signal is collected by the current sensor, and the reference data is read from the memory to perform fault analysis and diagnosis. It can analyze whether the magnetic bearing coil or the current sensor is faulty, and the detection is timely and accurate.

[0051] In some embodiments, the specific process of causing the bearing controller to output a drive signal to the power amplifier module when the power amplifier module is connected to the resistor module or the power amplifier module is connected to the magnetic bearing coil in step S120 is described in the following exemplary description.

[0052] The following is combined with Figure 4 The schematic diagram shown is a flowchart of an embodiment of the method of the present invention in which the bearing controller outputs a drive signal to the power amplifier module. It further illustrates the specific process of the bearing controller outputting a drive signal to the power amplifier module in step S120, including steps S410 to S420.

[0053] Step S410: When the power amplifier module and the resistor module are connected, the bearing controller outputs a drive signal required for a preset current threshold within a preset current range to the power amplifier module; wherein, the preset current range is a current of -10A to 10A, the preset current threshold is a current of 1A when the power amplifier module and the resistor module are connected, and the drive signal required for the preset current threshold is a drive signal a.

[0054] Step S420: If the current detection module is confirmed to be fault-free, and the power amplifier module is connected to the magnetic bearing coil, the bearing controller outputs a drive signal to the power amplifier module for any current from the first preset current to the nth preset current within a preset current range, where n is a positive integer; wherein, when n is greater than or equal to 2, the nth preset current is greater than the second preset current; the preset current range is, for example, a current of -10A to 10A; when the power amplifier module is connected to the magnetic bearing coil, the first preset current is, for example, a current of 1A; the drive signal required for the first preset current is, for example, a drive signal b; the nth preset current is, for example, a current of nA; and the currents from the second preset current to the nth preset current gradually increase.

[0055] In the present invention, the switching power amplifier (i.e., the power switching transistor in the bearing controller) generates different currents (i.e., the control current of the magnetic bearing, i.e., the current in the magnetic bearing coil) according to different drive signals (duty cycles). The different current values ​​corresponding to different drive signals (duty cycles) are stored. Subsequently, current control, detection and comparison are performed each time the machine is turned on, which can realize the detection and diagnosis of the magnetic bearing. When a fault occurs, the current output is shut off in time to avoid further damage to the compressor and the occurrence of safety problems.

[0056] In some implementations, when the power amplifier module is connected to the resistor module, the current detected by the current detection module is recorded as the current of the resistor module; when the power amplifier module is connected to the magnetic bearing coil, the current detected by the current detection module is recorded as the current of the magnetic bearing coil.

[0057] In step S140, based on the current detected by the current detection module, it is determined in stages whether the current detection module and the magnetic bearing coil are faulty. The specific process of controlling the start-up of the magnetic levitation compressor when it is determined that neither the current detection module nor the magnetic bearing coil is faulty is described in the following exemplary description.

[0058] The following is combined with Figure 5 The schematic diagram shown is a step-by-step flowchart of an embodiment of the method of the present invention for determining whether the current detection module and the magnetic bearing coil are faulty in stages. The specific process of determining whether the current detection module and the magnetic bearing coil are faulty in stages in step S140 is further explained, including steps S510 to S550.

[0059] Step S510, First stage: When the power amplifier module and the resistor module are connected, after the bearing controller outputs the drive signal required by the preset current threshold within the preset current range to the power amplifier module, determine whether the current detection module is faulty based on the current of the resistor module.

[0060] Step S520: If the current detection module is determined to be faulty, the bearing controller stops outputting drive signals to the power amplifier module and sends a faulty reminder message for the current detection module.

[0061] Step S530, Second Stage: If it is determined that the current detection module is not faulty, then when the power amplifier module is connected to the magnetic bearing coil, after the bearing controller outputs the drive signal required for any current from the first preset current to the nth preset current within the preset current range to the power amplifier module, it is determined whether the magnetic bearing coil is faulty based on the current of the magnetic bearing coil.

[0062] Step S540: If the magnetic bearing coil is determined to be faulty, the bearing controller stops outputting drive signals to the power amplifier module and sends a reminder message about the magnetic bearing coil fault.

[0063] Step S550: If it is determined that none of the magnetic bearing coils are faulty, then control the magnetic levitation compressor to start.

[0064] The present invention proposes an automatic fault detection device for magnetic bearing coil and current sensor in a magnetic levitation compressor. Before the magnetic levitation compressor is started, it automatically detects faults at multiple current value points of the current sensor and magnetic bearing to avoid abnormal compressor start-up. The abnormal point is located on the current sensor or magnetic bearing coil, and the faults of the current sensor, magnetic bearing coil open circuit and magnetic bearing coil short circuit are analyzed to improve the efficiency of fault diagnosis.

[0065] In some embodiments, after the bearing controller outputs the drive signal required for the preset current threshold within the preset current range to the power amplifier module in step S510, the specific process of determining whether the current detection module is faulty based on the current of the resistor module is described in the following exemplary description.

[0066] The following is combined with Figure 6 The flowchart shown is a schematic diagram of an embodiment of the method of the present invention for determining whether the current detection module is faulty. The specific process of determining whether the current detection module is faulty in step S510 is further explained, including steps S610 to S630.

[0067] Step S610: After the bearing controller outputs the drive signal required by the preset current threshold within the preset current range to the power amplifier module, it is determined whether the current of the resistor module is equal to the preset current threshold; wherein, the preset current threshold is a current of 1A.

[0068] Step S620: If it is determined whether the current of the resistor module is equal to the preset current threshold, then it is determined that the current detection module is not faulty. Then, when the power amplifier module is connected to the magnetic bearing coil, after the bearing controller outputs the drive signal required for any current from the first preset current to the nth preset current within the preset current range to the power amplifier module, it is determined whether the magnetic bearing coil is faulty based on the current of the magnetic bearing coil.

[0069] Step S630: If it is determined that the current of the resistor module is not equal to the preset current threshold, then the current detection module is determined to be faulty, so that the bearing controller stops outputting drive signals to the power amplifier module and initiates a reminder message of the current detection module fault.

[0070] Figure 12This is a flowchart illustrating a current sensor fault detection method. Figure 12 As shown, the current sensor fault detection process includes: Step 11: The magnetic levitation compressor receives the start command and then executes step 12.

[0071] Step 12: The bearing controller controls the multiplexer to close to position "1", that is, the control terminal of the bearing controller controls the multiplexer to connect with the first connection terminal (i.e., terminal 1) of the multiplexer, so that the bearing controller and the current limiting resistor form a path; the bearing controller sends a fixed drive signal a (such as the duty cycle required for a current of 1A) to the switching power amplifier (i.e., the power switching transistor in the bearing controller), and the switching power amplifier (i.e., the power switching transistor in the bearing controller) outputs current (such as a current of 1A) to the current limiting resistor, and then steps 13 are executed.

[0072] Step 13: The bearing controller acquires the current I of the current-limiting resistor through a current sensor. a Then proceed to step 14.

[0073] Step 14: Determine the current I of the current-limiting resistor. a Is the current not equal to the current threshold, such as 1A? If yes, proceed to step 15; otherwise, proceed to step 16. Note that different drive signals will generate different currents, and the current threshold range can generally be selected from -10A to 10A. Here, a current threshold of 1A is used as an example.

[0074] Step 15: Determine the current I of the current-limiting resistor. a If the current is not equal to the current threshold, such as 1A, then the current sensor is determined to be faulty, the magnetic levitation compressor is not allowed to start, and a current sensor fault message is reported.

[0075] Step 16: Determine the current I of the current-limiting resistor. a If the current is equal to the current threshold, such as 1A, then the current sensor is considered to be normal, and the magnetic bearing fault detection process can proceed.

[0076] In the solution of this invention, the current sensor fault detection is performed by controlling a multiplexer, and the magnetic bearing fault detection is performed only after the current sensor is confirmed to be normal.

[0077] In steps 14, 15, and 16, the current I of the current-limiting resistor is determined. aIf the current is not equal to the current threshold (e.g., 1A), then the current sensor is considered damaged due to inaccurate sampling. An abnormal fault is reported, enabling self-diagnosis and analysis of the current sensor fault, thus improving fault handling efficiency. Otherwise, the current sensor is considered normal, and magnetic bearing fault detection can be performed. Magnetic bearing coil detection is equivalent to magnetic bearing fault detection. First, the multiplexer is closed to terminal 1, meaning the bearing controller connects the control terminal of the multiplexer to the first connection terminal (terminal 1) of the multiplexer to perform current sensor fault detection. If the current sensor is determined to be normal after detection, then the multiplexer is closed to terminal 2, meaning the bearing controller connects the control terminal of the multiplexer to the second connection terminal (terminal 2) of the multiplexer to perform magnetic bearing fault detection.

[0078] In some implementations, after the bearing controller outputs a drive signal required for a first preset current within a preset current range to the power amplifier module, the current of the magnetic bearing coil obtained is recorded as the first current of the magnetic bearing coil; after the bearing controller outputs a drive signal required for a second preset current within a preset current range to the power amplifier module, the current of the magnetic bearing coil obtained is recorded as the second current of the magnetic bearing coil; and so on, after the bearing controller outputs a drive signal required for the nth preset current within a preset current range to the power amplifier module, the current of the magnetic bearing coil obtained is recorded as the nth current of the magnetic bearing coil. Wherein, the first current of the magnetic bearing coil is like the current I of the magnetic bearing coil. b The second current of the magnetic bearing coil is like the current I of the magnetic bearing coil. c The nth current of the magnetic bearing coil is like the current I of the magnetic bearing coil. n .

[0079] In step S530, after the bearing controller outputs the drive signal required for any current from the first preset current to the nth preset current within the preset current range to the power amplifier module, the specific process of determining whether the magnetic bearing coil is faulty based on the current of the magnetic bearing coil is described in the following exemplary description.

[0080] The following is combined with Figure 7 The flowchart shown is a schematic diagram of an embodiment of the method of the present invention for determining whether the magnetic bearing coil is faulty. The specific process of determining whether the magnetic bearing coil is faulty in step S530 is further explained, including steps S710 to S750.

[0081] Step S710: After the bearing controller outputs the drive signal required by the first preset current within the preset current range to the power amplifier module, determine whether the first current of the magnetic bearing coil is equal to 0.

[0082] Step S720: If it is determined that the first current of the magnetic bearing coil is equal to 0, then the magnetic bearing coil is determined to be faulty and is an open circuit fault, so that the bearing controller stops outputting drive signals to the power amplifier module and initiates a reminder message of the magnetic bearing coil fault.

[0083] Step S730: If it is determined that the first current of the magnetic bearing coil is not equal to 0, then determine whether the first current of the magnetic bearing coil is equal to the first preset current; wherein, the first preset current is such as current I0.

[0084] Step S740: If it is determined that the first current of the magnetic bearing coil is not equal to the first preset current, then the magnetic bearing coil is determined to be faulty, so that the bearing controller stops outputting drive signals to the power amplifier module and initiates a reminder message of the magnetic bearing coil fault.

[0085] Step S750: If it is determined that the first current of the magnetic bearing coil is equal to the first preset current, then after the bearing controller incrementally outputs the drive signal required by any current in the second preset current or the nth preset current within the preset current range to the power amplifier module, it continues to determine whether the magnetic bearing coil is faulty based on the current of the magnetic bearing coil.

[0086] In the solution of this invention, the multi-point detection magnetic bearing coil can not only detect whether the magnetic bearing is working properly, but also avoid the occurrence of large current and coil burnout when the magnetic bearing fails, thus ensuring the safety and reliability of the compressor.

[0087] In some embodiments, after the bearing controller incrementally outputs the drive signal required by any of the second preset current or the nth preset current within the preset current range to the power amplifier module in step S750, the process of further determining whether the magnetic bearing coil is faulty based on the current of the magnetic bearing coil is described in the following exemplary description.

[0088] The following is combined with Figure 8 The flowchart shown is a schematic diagram of an embodiment of the method of the present invention for further determining whether the magnetic bearing coil is faulty. The specific process of further determining whether the magnetic bearing coil is faulty in step S750 is further explained, including steps S810 to S840.

[0089] Step S810: The bearing controller outputs a drive signal required for the second preset current within a preset current range to the power amplifier module; after the bearing controller outputs the drive signal required for the second preset current within a preset current range to the power amplifier module, it is determined whether the second current of the magnetic bearing coil is equal to the second preset current; wherein, the second preset current is greater than the first preset current, and the second preset current is like current I1.

[0090] Step S820: If it is determined that the second current of the magnetic bearing coil is equal to the second preset current, then it is determined that the magnetic bearing is not faulty, and the magnetic levitation compressor is controlled to start; or, to further improve the detection accuracy, the drive signal required by the nth preset current within the preset current range is continued to be output to the power amplifier module; after the bearing controller outputs the drive signal required by the nth preset current within the preset current range to the power amplifier module, it is determined whether the nth current of the magnetic bearing coil is equal to the nth preset current; wherein, the nth preset current is greater than the second preset current, and the nth preset current is like current I. n-1 .

[0091] Step S830: If it is determined that the nth current of the magnetic bearing coil is equal to the nth preset current, then it is determined that the magnetic bearing is not faulty, so as to control the magnetic levitation compressor to start.

[0092] Step S840: If it is determined that the second current of the magnetic bearing coil is not equal to the second preset current, or if it is determined that the nth current of the magnetic bearing coil is not equal to the nth preset current, then the magnetic bearing coil is determined to be faulty, so that the bearing controller stops outputting drive signals to the power amplifier module and initiates a reminder message for the magnetic bearing coil fault.

[0093] Figure 13 This is a flowchart illustrating a magnetic bearing fault detection method. Figure 13 As shown, the process for detecting magnetic bearing faults includes: Step 21: If the current sensor is functioning correctly, the bearing controller controls the multiplexer to close to position "2". This connects the control terminal of the multiplexer to its first connection terminal (terminal 1), creating a path between the bearing controller and the magnetic bearing coil. The bearing controller sends a fixed drive signal b (such as the duty cycle required for current I0) to the switching power amplifier (the power switching transistor in the bearing controller). The switching power amplifier then outputs current to the magnetic bearing coil, and step 22 is executed. The current I0 can be set between -10A and 10A.

[0094] Step 22: The bearing controller acquires the current I of the magnetic bearing coil through a current sensor. b Then proceed to step 23.

[0095] Step 23: Determine the current I of the magnetic bearing coil. b Is it equal to 0A? If yes, proceed to step 28; otherwise, proceed to step 24.

[0096] Step 24: Determine the current I of the magnetic bearing coil. b Is it equal to the current I0? To determine if the current I in the magnetic bearing coil is equal to the current I0,b If the current is equal to I0, the bearing controller sends a fixed drive signal c (such as the duty cycle required for current I1) to the switching power amplifier (i.e., the power switching transistor in the bearing controller). The switching power amplifier (i.e., the power switching transistor in the bearing controller) outputs current to the magnetic bearing coil, and then proceeds to step 25; otherwise, proceeds to step 28.

[0097] Step 25: The bearing controller acquires the current I of the magnetic bearing coil through a current sensor. c Then proceed to step 26.

[0098] Step 26: Determine the current I of the magnetic bearing coil. c Is it equal to the current I1? If yes, proceed to step 27; otherwise, proceed to step 28.

[0099] Step 27: Determine the current I of the magnetic bearing coil. c If the current I1 is equal to the magnetic bearing detection, then the magnetic levitation compressor can be started.

[0100] Step 28: Determine the current I of the magnetic bearing coil. b It equals 0A, or if we want to determine the current I of the magnetic bearing coil... b Not equal to current I0, or to determine the current I of the magnetic bearing coil. c If the current is not equal to I1, the magnetic bearing is considered abnormal, the magnetic levitation compressor is not allowed to start, and a magnetic bearing failure message is reported.

[0101] In step 23, determine the current I of the magnetic bearing coil. b Is it equal to 0A? If yes, it indicates no current flow and an open circuit in the magnetic bearing coil, thus enabling self-diagnosis and improving fault handling efficiency by analyzing the open circuit fault in the magnetic bearing coil. Otherwise, it reads and stores data I0 (this is the current value corresponding to the drive signal b, which can be set from -10A to 10A), and samples the current value I... b Compare with the stored current value I0: if the deviation is within ±0.2A, the magnetic bearing coil is considered to be functioning normally at that point; otherwise, it is abnormal and an abnormal magnetic bearing fault is reported, such as an open circuit or short circuit fault in the magnetic bearing coil, to prevent abnormal current startup, which could further damage the compressor or cause a safety accident.

[0102] The subsequent multi-point detection in steps 24 to 28 follows the same principle. The selection of points can be based on the range of -10A to 10A, with one detection point corresponding to each 1A, and the detection is gradually increased. The detection is carried out one by one, and the detection stops when an abnormality is found. For safety reasons, direct detection of large currents (such as currents greater than 5A) should be avoided. Figure 13In the example shown, two points, current I0 and current I1, are given, and so on. For example, current I0 is 1A, current I1 is 2A, and so on. For each additional 1A of current, the corresponding drive signal is sent once, and the current magnitude is collected by a current sensor for comparison to see if there is any abnormality.

[0103] In this stepwise incremental detection, the current-driven signal is sent from small to large to avoid directly supplying a large current, which is dangerous. For example, a 1A current is sent first, and the sampled signal is used to check if it equals 1A. Then a 2A current is sent, and the sampled signal is used to check if it equals 2A, and so on.

[0104] Multi-point testing avoids the randomness of single-point testing. For example, a fluctuation within 1A ± 0.2A at a 1A current level is normal. However, due to aging of the magnetic bearing circuitry or corrosion of the coil connecting components leading to low resistance to ground or near-short circuit to ground, a small current test may pass normally, but a large current of 10A could potentially cause a short circuit to ground, further damaging the compressor and causing safety issues. Furthermore, direct high-current testing can burn out the coil. Therefore, multi-point testing, where fluctuations exceed 0.2A, indicates a magnetic bearing malfunction. This not only detects whether the magnetic bearing is functioning properly but also prevents large currents from occurring in the event of a magnetic bearing failure, ensuring the compressor's safety and reliability.

[0105] In some embodiments, the magnetic levitation compressor further includes a backup current detection module and a backup magnetic bearing coil; the backup current detection module and the current detection module are switchably configured, such as the backup current detection module being connected in parallel with the current detection module and being switchably used via a corresponding switch; the backup magnetic bearing coil and the magnetic bearing coil are switchably configured, such as the backup magnetic bearing coil being connected in parallel with the magnetic bearing coil and being switchably used via a corresponding switch.

[0106] The control method for the magnetic levitation compressor further includes: switching the backup current detection module and / or switching the backup magnetic bearing coil.

[0107] The following is combined with Figure 9 The schematic diagram shown is a flowchart of an embodiment of the method of the present invention for switching the backup current detection module and / or switching the backup magnetic bearing coil. It further illustrates the specific process of switching the backup current detection module and / or switching the backup magnetic bearing coil, including steps S910 to S920.

[0108] Step S910: After determining in stages whether the current detection module and the magnetic bearing coil are faulty based on the current detected by the current detection module, if the current detection module is determined to be faulty, the current detection module is switched to the backup current detection module; if the magnetic bearing coil is determined to be faulty, the magnetic bearing coil is switched to the backup magnetic bearing coil.

[0109] Step S920: Based on the backup current detection module or the current detection module that is not faulty, and the backup magnetic bearing coil or the magnetic bearing coil that is not faulty, control the magnetic levitation compressor to start.

[0110] In some alternative embodiments, an additional switch, current sensor, and magnetic bearing coil can be added. In the event of a fault, the system can quickly switch to a backup current sensor or magnetic bearing coil, preventing the compressor from failing due to a malfunction. (See figure) The technical solution of this embodiment, targeting a magnetic levitation compressor, is based on a bearing controller, a power amplifier module (such as a switching power amplifier), a magnetic bearing coil, and a current detection module (such as a current sensor) for detecting the current of the magnetic bearing coil. A resistor module (such as a current-limiting resistor) and a selection switch module (such as a multiplexer) are configured. The power amplifier module is connected to the control terminal of the selection switch module. The first connection terminal of the selection switch module is connected to the first connection terminal of the resistor module. The second connection terminal of the selection switch module is connected to the first connection terminal of the magnetic bearing coil, and the second connection terminal of the resistor module is connected to the second connection terminal of the magnetic bearing coil. Of course, in the magnetic levitation compressor, the output terminal of the bearing controller is connected to... The input terminal of the power amplifier module is connected, and the output terminal of the power amplifier module is connected to the control terminal of the selector switch module. The second connection terminal of the magnetic bearing coil is connected to the input terminal of the bearing controller after passing through the current detection module. When the magnetic levitation compressor receives a start-up command, the switching mode of the selector switch module is controlled before the magnetic levitation compressor starts up. First, the current detection module is checked for faults. If the current detection module is not faulty, the magnetic bearing coil is checked for faults. Only if the magnetic bearing coil is not faulty is the magnetic levitation compressor allowed to start up. Thus, by performing fault detection on the magnetic bearing and the current detection module before the magnetic levitation compressor starts up, and promptly shutting off the current output in case of a fault, the safe start-up and operation of the compressor is ensured.

[0111] According to an embodiment of the present invention, a control device for a magnetic levitation compressor corresponding to the control method for the magnetic levitation compressor is also provided. See also Figure 10The diagram shows a structural schematic of an embodiment of the device of the present invention. The magnetic levitation compressor includes a bearing controller, a power amplifier module, a magnetic bearing coil, and a current detection module (i.e., a current detection module for detecting the current of the magnetic bearing coil). A selection switch module is provided between the power amplifier module and the magnetic bearing coil, and a resistor module is provided at the magnetic bearing coil. The selection switch module can select whether the resistor module or the magnetic bearing coil is connected to the power amplifier module. The power amplifier module is, for example, a switching power amplifier (i.e., a power switching transistor in the bearing controller); the current detection module is, for example, a current sensor for detecting the current of the magnetic bearing coil; and the resistor module is, for example, a current-limiting resistor. In the solution of the present invention, as shown... Figure 10 As shown, the control device for the magnetic levitation compressor includes: an acquisition unit 102 and a control unit 104.

[0112] The control unit 104 is configured to, when the magnetic levitation compressor is powered on and a start-up command for the magnetic levitation compressor is received, cause the bearing controller to control the selection switch module to connect the power amplifier module to the resistor module or to the magnetic bearing coil. The specific functions and processing of this control unit 104 are described in step S110.

[0113] The control unit 104 is further configured to, when the power amplifier module is connected to the resistor module or the power amplifier module is connected to the magnetic bearing coil, cause the bearing controller to output a drive signal to the power amplifier module to energize the resistor module or the magnetic bearing coil. The specific functions and processing of this control unit 104 are further described in step S120.

[0114] The acquisition unit 102 is configured to acquire the current detected by the current detection module when the bearing controller outputs a drive signal to the power amplifier module. The specific function and processing of the acquisition unit 102 are described in step S130.

[0115] The control unit 104 is further configured to determine, in stages, whether the current detection module and the magnetic bearing coil are faulty based on the current detected by the current detection module, so as to control the magnetic levitation compressor to start if it is determined that neither the current detection module nor the magnetic bearing coil is faulty. Specifically, if it is determined that the current detection module and / or the magnetic bearing coil is faulty, the bearing controller stops outputting drive signals to the power amplifier module and initiates a fault warning message for the current detection module and / or the magnetic bearing coil; if it is determined that neither the current detection module nor the magnetic bearing coil is faulty, the magnetic levitation compressor is controlled to start. The specific functions and processing of this control unit 104 are also described in step S140.

[0116] The present invention proposes an automatic fault detection device for magnetic bearing coils and current sensors in a magnetic levitation compressor. This device can detect and diagnose faults in the magnetic bearings and current sensors before the magnetic levitation compressor is started, and promptly shut off the current output when a fault occurs, thereby preventing further damage to the compressor and safety issues.

[0117] In some embodiments, the control unit 104 causes the bearing controller to control the selection switch module to connect the power amplifier module to the resistor module or to connect the power amplifier module to the magnetic bearing coil, including the process of controlling the selection switch module as follows: The control unit 104 is further configured to cause the bearing controller to first control the selection switch module to connect the power amplifier module and the resistor module. The specific functions and processing of the control unit 104 are further described in step S210.

[0118] The control unit 104 is further configured to, upon determining that the current detection module is not faulty, cause the bearing controller to control the selection switch module to connect the power amplifier module to the magnetic bearing coil. The specific functions and processing of this control unit 104 are further described in step S220.

[0119] In the present invention, the bearing controller can drive the switching power amplifier (i.e., the power switching tube in the bearing controller) to work, thereby outputting control current to the current limiting resistor or the magnetic bearing coil. The current signal is collected by the current sensor, and based on the corresponding reference data, it can be analyzed whether the magnetic bearing coil or the current sensor is faulty, and the detection is timely and accurate.

[0120] In some embodiments, the selection switch module has a control terminal, a first connection terminal, and a second connection terminal. The power amplifier module is connected to the control terminal of the selection switch module, the first connection terminal of the selection switch module is connected to the first connection terminal of the resistor module, the second connection terminal of the selection switch module is connected to the first connection terminal of the magnetic bearing coil, and the second connection terminal of the resistor module is connected to the second connection terminal of the magnetic bearing coil. Specifically, a selection switch module and a resistor module are provided at the power amplifier module and the magnetic bearing coil. The output terminal of the power amplifier module is connected to the control terminal of the selection switch module, the first connection terminal of the selection switch module is connected to the first connection terminal of the resistor module, the second connection terminal of the selection switch module is connected to the first connection terminal of the magnetic bearing coil, and the second connection terminal of the resistor module is connected to the second connection terminal of the magnetic bearing coil. Of course, in the magnetic levitation compressor, the output terminal of the bearing controller is connected to the input terminal of the power amplifier module, the output terminal of the power amplifier module is connected to the control terminal of the selection switch module, and the second connection terminal of the magnetic bearing coil is connected to the input terminal of the bearing controller after passing through the current detection module.

[0121] The control unit 104 enables the bearing controller to control the selection switch module to connect the power amplifier module to the resistor module or to the magnetic bearing coil. The control unit also includes a process for controlling the terminals of the selection switch module, as detailed below: The control unit 104 is further configured to connect the control terminal of the selection switch module to the first connection terminal of the selection switch module, thereby connecting the power amplifier module to the resistor module. The specific functions and processing of this control unit 104 are further described in step S310.

[0122] The control unit 104 is further configured to, upon determining that the current detection module is not faulty, cause the bearing controller to connect the control terminal of the selection switch module to the second connection terminal of the selection switch module, thereby connecting the power amplifier module to the magnetic bearing coil. The specific functions and processing of this control unit 104 are further described in step S320.

[0123] Figure 11 This is a schematic diagram of the hardware circuit for an automatic fault detection device for the magnetic bearing coil and current sensor in a magnetic levitation compressor. Figure 11The hardware circuit of the automatic fault detection device for the magnetic bearing coil and current sensor in the magnetic levitation compressor shown is as follows: The automatic fault detection device for the magnetic bearing consists of a bearing controller, a memory, a switching amplifier (i.e., the power switching transistor in the bearing controller), a multiplexer, a current-limiting resistor, a magnetic bearing coil, and a current sensor. The multiplexer has a control terminal, a first connection terminal (i.e., terminal 1), and a second connection terminal (i.e., terminal 2). The switching amplifier (i.e., the power switching transistor in the bearing controller) is located in front of the magnetic bearing coil and its function is to supply current to the magnetic bearing coil. The switching amplifier (i.e., the power switching transistor in the bearing controller) can be a switching transistor in the inverter of the motor controller or a switching transistor in the Intelligent Power Module (IPM). This switching transistor can be an Insulated Gate Bipolar Transistor (IGBT).

[0124] The memory is connected to the bearing controller. The bearing controller outputs a drive signal to the switching power amplifier (i.e., the power switching transistor in the bearing controller). The switching power amplifier (i.e., the power switching transistor in the bearing controller) is connected to the control terminal of the multiplexer. The first connection terminal (i.e., terminal 1) of the multiplexer is connected to the first connection terminal of the current limiting resistor. The second connection terminal (i.e., terminal 2) of the multiplexer is connected to the first connection terminal of the magnetic bearing coil. After the second connection terminal of the current limiting resistor is connected to the second connection terminal of the magnetic bearing coil, it is connected to the bearing controller via the current sensor.

[0125] exist Figure 11 In the example shown, the bearing controller can control the multiplexer to select different paths. When the multiplexer is closed at "1", that is, when the control terminal of the multiplexer is connected to the first connection terminal (i.e., terminal 1) of the multiplexer, the bearing controller forms a path with the current limiting resistor, which can be used for current sensor fault detection. When the multiplexer is closed at "2", that is, when the control terminal of the multiplexer is connected to the second connection terminal (i.e., terminal 2) of the multiplexer, the bearing controller forms a path with the magnetic bearing coil, which can be used for magnetic bearing coil fault detection.

[0126] In the present invention, the bearing controller can drive the switching power amplifier (i.e., the power switching transistor in the bearing controller) to work, thereby outputting control current to the current limiting resistor or the magnetic bearing coil. The current signal is collected by the current sensor, and the reference data is read from the memory to perform fault analysis and diagnosis. It can analyze whether the magnetic bearing coil or the current sensor is faulty, and the detection is timely and accurate.

[0127] In some embodiments, when the power amplifier module is connected to the resistor module or the power amplifier module is connected to the magnetic bearing coil, the control unit 104 causes the bearing controller to output a drive signal to the power amplifier module, including: The control unit 104 is further configured to, when the power amplifier module and the resistor module are connected, cause the bearing controller to output a drive signal required by a preset current threshold within a preset current range to the power amplifier module; wherein, the preset current range is, for example, a current of -10A to 10A, the preset current threshold is, for example, a current of 1A when the power amplifier module and the resistor module are connected, and the drive signal required by the preset current threshold is, for example, drive signal a. The specific functions and processing of the control unit 104 are further described in step S410.

[0128] The control unit 104 is further configured to, when the current detection module is determined to be fault-free and the power amplifier module is connected to the magnetic bearing coil, cause the bearing controller to output a drive signal required for any current from a first preset current to an nth preset current within a preset current range to the power amplifier module, where n is a positive integer; wherein, when n is greater than or equal to 2, the nth preset current is greater than the second preset current; the preset current range is, for example, a current of -10A to 10A; when the power amplifier module is connected to the magnetic bearing coil, the first preset current is, for example, a current of 1A; the drive signal required for the first preset current is, for example, a drive signal b; the nth preset current is, for example, a current of nA; and the currents from the second preset current to the nth preset current gradually increase. The specific functions and processing of this control unit 104 are further described in step S420.

[0129] In the present invention, the switching power amplifier (i.e., the power switching transistor in the bearing controller) generates different currents (i.e., the control current of the magnetic bearing, i.e., the current in the magnetic bearing coil) according to different drive signals (duty cycles). The different current values ​​corresponding to different drive signals (duty cycles) are stored. Subsequently, current control, detection and comparison are performed each time the machine is turned on, which can realize the detection and diagnosis of the magnetic bearing. When a fault occurs, the current output is shut off in time to avoid further damage to the compressor and the occurrence of safety problems.

[0130] In some implementations, when the power amplifier module is connected to the resistor module, the current detected by the current detection module is recorded as the current of the resistor module; when the power amplifier module is connected to the magnetic bearing coil, the current detected by the current detection module is recorded as the current of the magnetic bearing coil.

[0131] The control unit 104 determines, in stages, whether the current detection module and the magnetic bearing coil are faulty based on the current detected by the current detection module, so as to control the magnetic levitation compressor to start when it is determined that neither the current detection module nor the magnetic bearing coil is faulty, including: The control unit 104 is further configured in the first stage: when the power amplifier module and the resistor module are connected, after the bearing controller outputs the drive signal required by the preset current threshold within the preset current range to the power amplifier module, it determines whether the current detection module is faulty based on the current of the resistor module. The specific functions and processing of this control unit 104 are further described in step S510.

[0132] The control unit 104 is further configured to, if a fault is determined in the current detection module, cause the bearing controller to stop outputting drive signals to the power amplifier module and initiate a fault warning message for the current detection module. The specific functions and processing of this control unit 104 are further described in step S520.

[0133] The control unit 104 is further configured in a second stage: if it is determined that the current detection module is not faulty, then, when the power amplifier module is connected to the magnetic bearing coil, after the bearing controller outputs the drive signal required for any current from the first preset current to the nth preset current within the preset current range to the power amplifier module, it determines whether the magnetic bearing coil is faulty based on the current of the magnetic bearing coil. The specific functions and processing of this control unit 104 are further described in step S530.

[0134] The control unit 104 is further configured to, if a fault is determined in the magnetic bearing coil, cause the bearing controller to stop outputting drive signals to the power amplifier module and initiate a fault warning message for the magnetic bearing coil. The specific functions and processing of this control unit 104 are further described in step S540.

[0135] The control unit 104 is further configured to control the magnetic levitation compressor to start if it is determined that none of the magnetic bearing coils are faulty. The specific functions and processing of the control unit 104 are further described in step S550.

[0136] The present invention proposes an automatic fault detection device for magnetic bearing coil and current sensor in a magnetic levitation compressor. Before the magnetic levitation compressor is started, it automatically detects faults at multiple current value points of the current sensor and magnetic bearing to avoid abnormal compressor start-up. The abnormal point is located on the current sensor or magnetic bearing coil, and the faults of the current sensor, magnetic bearing coil open circuit and magnetic bearing coil short circuit are analyzed to improve the efficiency of fault diagnosis.

[0137] In some embodiments, after the bearing controller outputs a drive signal required for a preset current threshold within a preset current range to the power amplifier module, the control unit 104 determines whether the current detection module is faulty based on the current of the resistor module, including: The control unit 104 is further configured to determine whether the current of the resistor module is equal to the preset current threshold after the bearing controller outputs the drive signal required for the preset current threshold within the preset current range to the power amplifier module; wherein, the preset current threshold is, for example, a current of 1A. The specific functions and processing of the control unit 104 are further described in step S610.

[0138] The control unit 104 is further configured to determine whether the current detection module is fault-free if it is determined whether the current of the resistor module is equal to a preset current threshold. Then, when the power amplifier module is connected to the magnetic bearing coil, after the bearing controller outputs the drive signal required for any current from the first preset current to the nth preset current within the preset current range to the power amplifier module, it determines whether the magnetic bearing coil is faulty based on the current of the magnetic bearing coil. The specific functions and processing of this control unit 104 are further described in step S620.

[0139] The control unit 104 is further configured to determine a fault in the current detection module if it is determined that the current of the resistor module is not equal to a preset current threshold, thereby causing the bearing controller to stop outputting drive signals to the power amplifier module and initiating a fault warning message for the current detection module. The specific functions and processing of this control unit 104 are further described in step S630.

[0140] Figure 12 This is a flowchart illustrating a current sensor fault detection method. Figure 12 As shown, the current sensor fault detection process includes: Step 11: The magnetic levitation compressor receives the start command and then executes step 12.

[0141] Step 12: The bearing controller controls the multiplexer to close to position "1", that is, the control terminal of the bearing controller controls the multiplexer to connect with the first connection terminal (i.e., terminal 1) of the multiplexer, so that the bearing controller and the current limiting resistor form a path; the bearing controller sends a fixed drive signal a (such as the duty cycle required for a current of 1A) to the switching power amplifier (i.e., the power switching transistor in the bearing controller), and the switching power amplifier (i.e., the power switching transistor in the bearing controller) outputs current (such as a current of 1A) to the current limiting resistor, and then steps 13 are executed.

[0142] Step 13: The bearing controller acquires the current I of the current-limiting resistor through a current sensor. a Then proceed to step 14.

[0143] Step 14: Determine the current I of the current-limiting resistor. aIs the current not equal to the current threshold, such as 1A? If yes, proceed to step 15; otherwise, proceed to step 16. Note that different drive signals will generate different currents, and the current threshold range can generally be selected from -10A to 10A. Here, a current threshold of 1A is used as an example.

[0144] Step 15: Determine the current I of the current-limiting resistor. a If the current is not equal to the current threshold, such as 1A, then the current sensor is determined to be faulty, the magnetic levitation compressor is not allowed to start, and a current sensor fault message is reported.

[0145] Step 16: Determine the current I of the current-limiting resistor. a If the current is equal to the current threshold, such as 1A, then the current sensor is considered to be normal, and the magnetic bearing fault detection process can proceed.

[0146] In the solution of this invention, the current sensor fault detection is performed by controlling a multiplexer, and the magnetic bearing fault detection is performed only after the current sensor is confirmed to be normal.

[0147] In steps 14, 15, and 16, the current I of the current-limiting resistor is determined. a If the current is not equal to the current threshold (e.g., 1A), then the current sensor is considered damaged due to inaccurate sampling. An abnormal fault is reported, enabling self-diagnosis and analysis of the current sensor fault, thus improving fault handling efficiency. Otherwise, the current sensor is considered normal, and magnetic bearing fault detection can be performed. Magnetic bearing coil detection is equivalent to magnetic bearing fault detection. First, the multiplexer is closed to terminal 1, meaning the bearing controller connects the control terminal of the multiplexer to the first connection terminal (terminal 1) of the multiplexer to perform current sensor fault detection. If the current sensor is determined to be normal after detection, then the multiplexer is closed to terminal 2, meaning the bearing controller connects the control terminal of the multiplexer to the second connection terminal (terminal 2) of the multiplexer to perform magnetic bearing fault detection.

[0148] In some implementations, after the bearing controller outputs a drive signal required for a first preset current within a preset current range to the power amplifier module, the current of the magnetic bearing coil obtained is recorded as the first current of the magnetic bearing coil; after the bearing controller outputs a drive signal required for a second preset current within a preset current range to the power amplifier module, the current of the magnetic bearing coil obtained is recorded as the second current of the magnetic bearing coil; and so on, after the bearing controller outputs a drive signal required for the nth preset current within a preset current range to the power amplifier module, the current of the magnetic bearing coil obtained is recorded as the nth current of the magnetic bearing coil. Wherein, the first current of the magnetic bearing coil is like the current I of the magnetic bearing coil. bThe second current of the magnetic bearing coil is like the current I of the magnetic bearing coil. c The nth current of the magnetic bearing coil is like the current I of the magnetic bearing coil. n .

[0149] After the bearing controller outputs the drive signal required by any current from the first preset current to the nth preset current within the preset current range to the power amplifier module, the control unit 104 determines whether the magnetic bearing coil is faulty based on the current of the magnetic bearing coil, including: The control unit 104 is further configured to determine whether the first current of the magnetic bearing coil is equal to 0 after the bearing controller outputs the drive signal required for the first preset current within the preset current range to the power amplifier module. The specific functions and processing of the control unit 104 are further described in step S710.

[0150] The control unit 104 is further configured to determine that the magnetic bearing coil is faulty and has an open circuit fault if the first current of the magnetic bearing coil is determined to be 0, thereby causing the bearing controller to stop outputting drive signals to the power amplifier module and initiating a fault warning message for the magnetic bearing coil. The specific functions and processing of this control unit 104 are further described in step S720.

[0151] The control unit 104 is further configured to determine whether the first current of the magnetic bearing coil is equal to a first preset current if it is determined that the first current of the magnetic bearing coil is not equal to 0; wherein the first preset current is, for example, current I0. The specific functions and processing of the control unit 104 are further described in step S730.

[0152] The control unit 104 is further configured to determine a magnetic bearing coil fault if it is determined that the first current of the magnetic bearing coil is not equal to the first preset current, thereby causing the bearing controller to stop outputting drive signals to the power amplifier module and initiating a fault warning message for the magnetic bearing coil. The specific functions and processing of this control unit 104 are further described in step S740.

[0153] The control unit 104 is further configured to, if it is determined that the first current of the magnetic bearing coil is equal to the first preset current, then cause the bearing controller to incrementally output the drive signal required by any of the second preset current or the nth preset current within the preset current range to the power amplifier module, and then continue to determine whether the magnetic bearing coil is faulty based on the current of the magnetic bearing coil. The specific functions and processing of this control unit 104 are further described in step S750.

[0154] In the solution of this invention, the multi-point detection magnetic bearing coil can not only detect whether the magnetic bearing is working properly, but also avoid the occurrence of large current and coil burnout when the magnetic bearing fails, thus ensuring the safety and reliability of the compressor.

[0155] In some embodiments, after the control unit 104 causes the bearing controller to incrementally output the drive signal required by any current from the second preset current or the nth preset current within a preset current range to the power amplifier module, it continues to determine whether the magnetic bearing coil is faulty based on the current of the magnetic bearing coil, including: The control unit 104 is further configured to cause the bearing controller to output a drive signal required for a second preset current within a preset current range to the power amplifier module; after the bearing controller outputs the drive signal required for a second preset current within a preset current range to the power amplifier module, it determines whether the second current of the magnetic bearing coil is equal to the second preset current; wherein the second preset current is greater than the first preset current, and the second preset current is like current I1. The specific functions and processing of this control unit 104 are further described in step S810.

[0156] The control unit 104 is further configured to determine that the magnetic bearing is not faulty if it is determined that the second current of the magnetic bearing coil is equal to the second preset current, and to control the magnetic levitation compressor to start; or, to further improve the detection accuracy, to continue to output the drive signal required by the nth preset current within the preset current range to the power amplifier module; after the bearing controller outputs the drive signal required by the nth preset current within the preset current range to the power amplifier module, to determine whether the nth current of the magnetic bearing coil is equal to the nth preset current; wherein, the nth preset current is greater than the second preset current, and the nth preset current is like current I. n-1 For details on the specific functions and processing of the control unit 104, please refer to step S820.

[0157] The control unit 104 is further configured to determine that the magnetic bearing is not faulty if it is determined that the nth current of the magnetic bearing coil is equal to the nth preset current, so as to control the magnetic levitation compressor to start. The control unit 104 is further configured to determine a magnetic bearing coil fault if it is determined that the second current of the magnetic bearing coil is not equal to the second preset current, or if it is determined that the nth current of the magnetic bearing coil is not equal to the nth preset current, thereby causing the bearing controller to stop outputting drive signals to the power amplifier module and initiating a fault warning message for the magnetic bearing coil. The specific functions and processing of this control unit 104 are further described in step S830.

[0158] Figure 13 This is a flowchart illustrating a magnetic bearing fault detection method. Figure 13As shown, the process for detecting magnetic bearing faults includes: Step 21: If the current sensor is functioning correctly, the bearing controller controls the multiplexer to close to position "2". This connects the control terminal of the multiplexer to its first connection terminal (terminal 1), creating a path between the bearing controller and the magnetic bearing coil. The bearing controller sends a fixed drive signal b (such as the duty cycle required for current I0) to the switching power amplifier (the power switching transistor in the bearing controller). The switching power amplifier then outputs current to the magnetic bearing coil, and step 22 is executed. The current I0 can be set between -10A and 10A.

[0159] Step 22: The bearing controller acquires the current I of the magnetic bearing coil through a current sensor. b Then proceed to step 23.

[0160] Step 23: Determine the current I of the magnetic bearing coil. b Is it equal to 0A? If yes, proceed to step 28; otherwise, proceed to step 24.

[0161] Step 24: Determine the current I of the magnetic bearing coil. b Is it equal to the current I0? To determine if the current I in the magnetic bearing coil is equal to the current I0, b If the current is equal to I0, the bearing controller sends a fixed drive signal c (such as the duty cycle required for current I1) to the switching power amplifier (i.e., the power switching transistor in the bearing controller). The switching power amplifier (i.e., the power switching transistor in the bearing controller) outputs current to the magnetic bearing coil, and then proceeds to step 25; otherwise, proceeds to step 28.

[0162] Step 25: The bearing controller acquires the current I of the magnetic bearing coil through a current sensor. c Then proceed to step 26.

[0163] Step 26: Determine the current I of the magnetic bearing coil. c Is it equal to the current I1? If yes, proceed to step 27; otherwise, proceed to step 28.

[0164] Step 27: Determine the current I of the magnetic bearing coil. c If the current I1 is equal to the magnetic bearing detection, then the magnetic levitation compressor can be started.

[0165] Step 28: Determine the current I of the magnetic bearing coil. b It equals 0A, or if we want to determine the current I of the magnetic bearing coil... b Not equal to current I0, or to determine the current I of the magnetic bearing coil. c If the current is not equal to I1, the magnetic bearing is considered abnormal, the magnetic levitation compressor is not allowed to start, and a magnetic bearing failure message is reported.

[0166] In step 23, determine the current I of the magnetic bearing coil. b Is it equal to 0A? If yes, it indicates no current flow and an open circuit in the magnetic bearing coil, thus enabling self-diagnosis and improving fault handling efficiency by analyzing the open circuit fault in the magnetic bearing coil. Otherwise, it reads and stores data I0 (this is the current value corresponding to the drive signal b, which can be set from -10A to 10A), and samples the current value I... b Compare with the stored current value I0: if the deviation is within ±0.2A, the magnetic bearing coil is considered to be functioning normally at that point; otherwise, it is abnormal and a magnetic bearing fault is reported to prevent abnormal current startup, which could further damage the compressor or cause a safety accident.

[0167] The subsequent multi-point detection in steps 24 to 28 follows the same pattern. The selection of points can be based on the range of -10A to 10A, with one detection point corresponding to every 1A, and the detection is gradually increased. For safety reasons, direct detection of large currents (such as currents greater than 5A) should be avoided. Figure 13 In the example shown, two points, current I0 and current I1, are given, and so on. For example, current I0 is 1A, current I1 is 2A, and so on. For each additional 1A of current, the corresponding drive signal is sent once, and the current magnitude is collected by a current sensor for comparison to see if there is any abnormality.

[0168] In this stepwise incremental detection, the current-driven signal is sent from small to large to avoid directly supplying a large current, which is dangerous. For example, a 1A current is sent first, and the sampled signal is used to check if it equals 1A. Then a 2A current is sent, and the sampled signal is used to check if it equals 2A, and so on.

[0169] Multi-point testing avoids the randomness of single-point testing. For example, a fluctuation within 1A ± 0.2A at a 1A current level is normal. However, due to aging of the magnetic bearing circuitry or corrosion of the coil connecting components leading to low resistance to ground or near-short circuit to ground, a small current test may pass normally, but a large current of 10A could potentially cause a short circuit to ground, further damaging the compressor and causing safety issues. Furthermore, direct high-current testing can burn out the coil. Therefore, multi-point testing, where fluctuations exceed 0.2A, indicates a magnetic bearing malfunction. This not only detects whether the magnetic bearing is functioning properly but also prevents large currents from occurring in the event of a magnetic bearing failure, ensuring the compressor's safety and reliability.

[0170] In some embodiments, the magnetic levitation compressor further includes a backup current detection module and a backup magnetic bearing coil; the backup current detection module and the current detection module are switchably configured, such as the backup current detection module being connected in parallel with the current detection module and being switchably used via a corresponding switch; the backup magnetic bearing coil and the magnetic bearing coil are switchably configured, such as the backup magnetic bearing coil being connected in parallel with the magnetic bearing coil and being switchably used via a corresponding switch.

[0171] The control device for the magnetic levitation compressor described in this invention further includes: a process for switching the backup current detection module and / or switching the backup magnetic bearing coil, as detailed below: The control unit 104 is further configured to, after determining in stages whether the current detection module and the magnetic bearing coil are faulty based on the current detected by the current detection module, switch the current detection module to the backup current detection module if the current detection module is determined to be faulty, and switch the magnetic bearing coil to the backup magnetic bearing coil if the magnetic bearing coil is determined to be faulty. The specific functions and processing of this control unit 104 are further described in step S910.

[0172] The control unit 104 is further configured to control the start-up of the magnetic levitation compressor based on the backup current detection module or the fault-free current detection module, and the backup magnetic bearing coil or the fault-free magnetic bearing coil. The specific functions and processing of this control unit 104 are further described in step S920.

[0173] In some alternative embodiments, an additional switch, current sensor, and magnetic bearing coil can be added to quickly switch to a backup current sensor or magnetic bearing coil in the event of a fault, thus preventing the compressor from failing to operate due to the fault. Figure 14 This is another hardware circuit diagram of an automatic fault detection device for the magnetic bearing coil and current sensor in a magnetic levitation compressor. Figure 14 As shown, when a fault is detected, the system switches to a backup current sensor and magnetic bearing coil. The magnetic bearing coil is redundantly located in the magnetic bearing, while the current sensor and switch are redundantly located in the bearing controller.

[0174] Since the processing and functions implemented by the device in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in the description of this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0175] According to an embodiment of the present invention, a magnetic levitation compressor corresponding to a control device for a magnetic levitation compressor is also provided. This magnetic levitation compressor may include the control device for a magnetic levitation compressor described above.

[0176] Since the processing and functions implemented by the magnetic levitation compressor in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned device, any details not covered in this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0177] According to an embodiment of the present invention, a computer program product corresponding to the control method for a magnetic levitation compressor is also provided, comprising a computer program that, when executed by a processor, implements the steps of the control method for the magnetic levitation compressor described above.

[0178] Since the processing and functions implemented by the product in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in the description of this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0179] According to an embodiment of the present invention, a storage medium corresponding to a control method for a magnetic levitation compressor is also provided. The storage medium includes a stored program, wherein, when the program is executed, the device where the storage medium is located executes the steps of the control method for the magnetic levitation compressor described above.

[0180] Since the processing and functions implemented by the storage medium in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned methods, any details not covered in this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0181] In summary, it is readily understood by those skilled in the art that, without conflict, the aforementioned advantageous methods can be freely combined and superimposed.

[0182] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A control method of a magnetic levitation compressor, characterized by, The magnetic suspension compressor has a bearing controller, a power amplifier module, a magnetic bearing coil and a current detection module; a selection switch module is arranged between the power amplifier module and the magnetic bearing coil, and a resistance module is arranged at the magnetic bearing coil; the selection switch module can select the resistance module or the magnetic bearing coil to be connected with the power amplifier module; The control method of the magnetic suspension compressor comprises: In the case of receiving the start-up instruction of the magnetic suspension compressor, the selection switch module is controlled to connect the power amplifier module with the resistance module or to connect the power amplifier module with the magnetic bearing coil; In the case of connecting the power amplifier module with the resistance module or connecting the power amplifier module with the magnetic bearing coil, the bearing controller is enabled to output a driving signal to the power amplifier module; In the case of the bearing controller outputting the driving signal to the power amplifier module, the current detected by the current detection module is acquired; According to the current detected by the current detection module, whether the current detection module and the magnetic bearing coil are faulty is determined in stages, so that in the case of determining that neither the current detection module nor the magnetic bearing coil is faulty, the magnetic suspension compressor is started up.

2. The control method of the magnetic levitation compressor according to claim 1, characterized by, Wherein, The selection switch module is controlled to connect the power amplifier module with the resistance module or to connect the power amplifier module with the magnetic bearing coil, comprising: The selection switch module is first controlled to connect the power amplifier module with the resistance module; In the case of determining that the current detection module is not faulty, the selection switch module is further controlled to connect the power amplifier module with the magnetic bearing coil; And / or, The selection switch module has a control end, a first connection end and a second connection end; the power amplifier module is connected with the control end of the selection switch module, the first connection end of the selection switch module is connected with the first connection end of the resistance module, the second connection end of the selection switch module is connected with the first connection end of the magnetic bearing coil, and the second connection end of the resistance module is connected with the second connection end of the magnetic bearing coil; The selection switch module is controlled to connect the power amplifier module with the resistance module or to connect the power amplifier module with the magnetic bearing coil, further comprising: The control end of the selection switch module is controlled to be connected with the first connection end of the selection switch module, so as to connect the power amplifier module with the resistance module; In the case of determining that the current detection module is not faulty, the control end of the selection switch module is further controlled to be connected with the second connection end of the selection switch module, so as to connect the power amplifier module with the magnetic bearing coil.

3. The control method of a magnetic levitation compressor according to claim 1 or 2, characterized in that, In the case of connecting the power amplifier module with the resistance module or connecting the power amplifier module with the magnetic bearing coil, the bearing controller is enabled to output a driving signal to the power amplifier module, comprising: In the case of connecting the power amplifier module with the resistance module, the bearing controller is enabled to output a driving signal required by a preset current threshold value in a preset current range to the power amplifier module; In the case of connecting the power amplifier module with the resistance module, the bearing controller is enabled to output a driving signal required by a preset current threshold value in a preset current range to the power amplifier module; In the case that the power amplifier module is connected with the magnetic bearing coil, the bearing controller outputs the drive signal required by any current from the first preset current to the n-th preset current in the preset current range to the power amplifier module, n is a positive integer; wherein, in the case that n is greater than or equal to 2, the n-th preset current is greater than the second preset current.

4. The control method of a magnetic levitation compressor according to any one of claims 1 to 3, characterized by, In the case that the power amplifier module is connected with the resistance module, the current detected by the current detection module is recorded as the current of the resistance module; in the case that the power amplifier module is connected with the magnetic bearing coil, the current detected by the current detection module is recorded as the current of the magnetic bearing coil; According to the current detected by the current detection module, the current detection module and the magnetic bearing coil are determined whether to be faulty in stages, so as to control the magnetic levitation compressor to start in the case that the current detection module and the magnetic bearing coil are determined to be not faulty, comprising: In the case that the power amplifier module is connected with the resistance module, after the bearing controller outputs the drive signal required by the preset current threshold in the preset current range to the power amplifier module, whether the current detection module is faulty is determined according to the current of the resistance module; If it is determined that the current detection module is faulty, the bearing controller stops outputting the drive signal to the power amplifier module, and initiates the prompt message of the current detection module failure; In the case that the power amplifier module is connected with the magnetic bearing coil, after the bearing controller outputs the drive signal required by any current from the first preset current to the n-th preset current in the preset current range to the power amplifier module, whether the magnetic bearing coil is faulty is determined according to the current of the magnetic bearing coil; If it is determined that the magnetic bearing coil is faulty, the bearing controller stops outputting the drive signal to the power amplifier module, and initiates the prompt message of the magnetic bearing coil failure; If it is determined that the magnetic bearing coil is not faulty, the magnetic levitation compressor is controlled to start.

5. The control method of a magnetic levitation compressor according to claim 4, characterized by, Wherein, After the bearing controller outputs the drive signal required by the preset current threshold in the preset current range to the power amplifier module, whether the current detection module is faulty is determined according to the current of the resistance module, comprising: After the bearing controller outputs the drive signal required by the preset current threshold in the preset current range to the power amplifier module, whether the current of the resistance module is equal to the preset current threshold is determined; If it is determined that the current of the resistance module is equal to the preset current threshold, it is determined that the current detection module is not faulty; If it is determined that the current of the resistance module is not equal to the preset current threshold, it is determined that the current detection module is faulty; And / or, The current of the magnetic bearing coil is recorded as the first current of the magnetic bearing coil after the bearing controller outputs the drive signal required by the power amplifier module to output the first preset current in the preset current range. The current of the magnetic bearing coil is recorded as the second current of the magnetic bearing coil after the bearing controller outputs the drive signal required by the power amplifier module to output the second preset current in the preset current range. The current of the magnetic bearing coil is recorded as the n-th current of the magnetic bearing coil after the bearing controller outputs the drive signal required by the power amplifier module to output the n-th preset current in the preset current range. After the bearing controller outputs the drive signal required by the power amplifier module to output any current in the first preset current to the n-th preset current in the preset current range, whether the magnetic bearing coil is faulty is determined according to the current of the magnetic bearing coil, including: After the bearing controller outputs the drive signal required by the power amplifier module to output the first preset current in the preset current range, whether the first current of the magnetic bearing coil is equal to 0 is determined. If it is determined that the first current of the magnetic bearing coil is equal to 0, it is determined that the magnetic bearing coil is faulty and is open circuit failure of the magnetic bearing coil. If it is determined that the first current of the magnetic bearing coil is not equal to 0, whether the first current of the magnetic bearing coil is equal to the first preset current is determined.

6. The control method of a magnetic levitation compressor according to claim 5, characterized by, If it is determined that the first current of the magnetic bearing coil is not equal to the first preset current, it is determined that the magnetic bearing coil is faulty. If it is determined that the first current of the magnetic bearing coil is equal to the first preset current, the bearing controller is caused to output the drive signal required by the power amplifier module to output any current in the second preset current to the n-th preset current in the preset current range in an incremental manner, and then the current of the magnetic bearing coil is continuously determined according to the current of the magnetic bearing coil to continuously determine whether the magnetic bearing coil is faulty. After the bearing controller outputs the drive signal required by the power amplifier module to output any current in the second preset current to the n-th preset current in the preset current range in an incremental manner, the current of the magnetic bearing coil is continuously determined according to the current of the magnetic bearing coil to continuously determine whether the magnetic bearing coil is faulty, including: The bearing controller is caused to output the drive signal required by the power amplifier module to output the second preset current in the preset current range; after the bearing controller causes the bearing controller to output the drive signal required by the power amplifier module to output the second preset current in the preset current range, whether the second current of the magnetic bearing coil is equal to the second preset current is determined; wherein the second preset current is greater than the first preset current. If it is determined that the second current of the magnetic bearing coil is equal to the second preset current, it is determined that the magnetic bearing is not faulty; or the bearing controller is caused to output the drive signal required by the power amplifier module to output the n-th preset current in the preset current range; after the bearing controller outputs the drive signal required by the power amplifier module to output the n-th preset current in the preset current range, whether the n-th current of the magnetic bearing coil is equal to the n-th preset current is determined; wherein the n-th preset current is greater than the second preset current. If it is determined that the n th current of the magnetic bearing coil is equal to the n th preset current, it is determined that the magnetic bearing is not faulty; If it is determined that the second current of the magnetic bearing coil is not equal to the second preset current, or it is determined that the n th current of the magnetic bearing coil is not equal to the n th preset current, it is determined that the magnetic bearing coil is faulty.

7. The control method of a magnetic levitation compressor according to any one of claims 1 to 6, characterized by, The magnetic suspension compressor further has a backup current detection module and a backup magnetic bearing coil; the backup current detection module and the current detection module are switchably arranged; the backup magnetic bearing coil and the magnetic bearing coil are switchably arranged. The control method of the magnetic suspension compressor further comprises: After determining whether the current detection module and the magnetic bearing coil are faulty in stages according to the current detected by the current detection module, if it is determined that the current detection module is faulty, the current detection module is switched to the backup current detection module; if it is determined that the magnetic bearing coil is faulty, the magnetic bearing coil is switched to the backup magnetic bearing coil; Based on the backup current detection module or the non-faulty current detection module, and the backup magnetic bearing coil or the non-faulty magnetic bearing coil, the magnetic suspension compressor is controlled to start.

8. A control device for a magnetic levitation compressor, characterized by The magnetic suspension compressor has a bearing controller, a power amplifier module, a magnetic bearing coil and a current detection module; a selection switch module is arranged between the power amplifier module and the magnetic bearing coil, and a resistance module is arranged at the magnetic bearing coil; the selection switch module can select the resistance module or the magnetic bearing coil to be connected with the power amplifier module; The control device of the magnetic suspension compressor comprises: A control unit is configured to, in a case where a start instruction of the magnetic suspension compressor is received, control the selection switch module to connect the power amplifier module with the resistance module or connect the power amplifier module with the magnetic bearing coil; The control unit is further configured to, in a case where the power amplifier module is connected with the resistance module or the power amplifier module is connected with the magnetic bearing coil, control the bearing controller to output a driving signal to the power amplifier module; A obtaining unit is configured to, in a case where the bearing controller outputs a driving signal to the power amplifier module, obtain a current detected by the current detection module; The control unit is further configured to determine whether the current detection module and the magnetic bearing coil are faulty in stages according to the current detected by the current detection module, so as to control the magnetic suspension compressor to start in a case where it is determined that the current detection module and the magnetic bearing coil are both non-faulty.

9. A magnetic levitation compressor characterized by, Comprise: The control device of the magnetic suspension compressor according to claim 8.

10. A storage medium, characterized by The storage medium comprises a stored program, wherein the program controls a device where the storage medium is located to execute the control method of the magnetic suspension compressor according to any one of claims 1 to 7 when the program is running.

11. A computer program product comprising a computer program, characterized in that, The computer program is executed by a processor to implement the steps of the control method of the magnetic suspension compressor according to any one of claims 1 to 7.

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