Energy feedback device and method for a magnetic bearing system and magnetic bearing system

Abstract

The application discloses an energy feedback device and method of a magnetic suspension bearing system and a magnetic suspension system. The energy feedback device comprises a first energy feedback path composed of a motor, a controllable inverter module, a power module and a magnetic suspension bearing system connected in sequence, and a second energy feedback path composed of the motor, the controllable inverter module, a path switching module and the magnetic suspension bearing system connected in sequence. When the commercial power is abnormally cut off, the motor is idled to generate electric energy feedback, and the electric energy is transmitted to the magnetic suspension bearing system through the first energy feedback path according to a first energy feedback voltage; when it is monitored that the bearing voltage of the magnetic suspension bearing system is less than the stable working voltage thereof, the first energy feedback voltage is adjusted to be a second energy feedback voltage, and the magnetic suspension bearing system is supplied with energy through the second energy feedback path, so that the magnetic suspension bearing system continues to keep a working state, the working time is prolonged, and the rotor zero-speed drop is ensured.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to an energy feedback device, method, and magnetic levitation system for a magnetic levitation bearing system. Background Technology

[0002] Magnetic levitation bearings use electromagnetic force to levitate the rotor in the air, eliminating mechanical contact between the stator and rotor. Compared to traditional rolling bearings, sliding bearings, and oil film bearings, magnetic bearings eliminate mechanical contact, allowing the rotor to operate at very high speeds. They offer advantages such as low mechanical wear, low energy consumption, low noise, long lifespan, no lubrication required, and no oil pollution. Electromagnetic bearings have corresponding bearing controllers, which are equipped with power supplies. Because the rotor is supported by electromagnetic force, if the bearing controller loses power during high-speed operation, the rotor will inevitably fall and collide at high speed, causing damage to the magnetic levitation bearing system.

[0003] To address the issue of high-speed drops during power outages, current solutions for magnetic levitation bearing systems typically involve incorporating a UPS (Uninterruptible Power Supply) or a motor energy feedback system. This ensures that the bearing controller can maintain normal operation for a short period in the event of a sudden external power outage. However, UPS systems are costly and complex to design, and are gradually being phased out. Another solution is to use a motor energy feedback system, such as... Figure 1 As shown, Figure 1 This diagram illustrates energy feedback in a current magnetic levitation system. When the mains power suddenly fails, the motor coasts back up, feeding electrical energy back to the DC bus via a controllable inverter module to power the bearing controller and maintain rotor levitation. However, in some situations (e.g., with high inertia), after a mains power failure, the bearing controller is powered by energy feedback, but the energy is insufficient to sustain its operation. When the bearing controller power fails, the rotor continues to coast, causing it to fall and wear down, ultimately damaging the magnetic levitation bearing system. Summary of the Invention

[0004] The embodiments of the present invention provide an energy feedback device, method and magnetic levitation system for a magnetic levitation bearing system, which aims to solve the problem of the rotor falling at high speed and damaging the magnetic levitation system when the power is cut off in existing magnetic levitation bearing systems.

[0005] This invention provides an energy feedback device for a magnetic levitation bearing system, comprising: a motor, a motor controller, a controllable inverter module, a power supply module, a monitoring module, and a path switching module;

[0006] The motor, the controllable inverter module, the power supply module, and the magnetic levitation bearing system are sequentially connected and configured as the first energy feedback path;

[0007] The motor, the controllable inverter module, the path switching module, and the magnetic levitation bearing system are sequentially connected and configured as a second energy feedback path;

[0008] The motor controller is connected to the monitoring module, the path switching module, and the controllable inverter module, and the monitoring module is connected to the magnetic levitation bearing system.

[0009] In the energy feedback device of the magnetic levitation bearing system provided by the present invention, the controllable inverter module is connected to the mains power through a DC bus, and the power supply module is connected to the DC bus and the magnetic levitation bearing system respectively.

[0010] In the energy feedback device of the magnetic levitation bearing system provided by the present invention, the path switching module is connected in parallel with the power supply module.

[0011] In the energy feedback device of the magnetic levitation bearing system provided by the present invention, the path switching module includes a controllable switching element, the controllable switching element includes a first end, a second end and a third end, the first end and the second end are respectively connected to the two ends of the power supply module, and the third end is connected to the motor controller.

[0012] In the energy feedback device of the magnetic levitation bearing system provided by the present invention, when the controllable switch element is open, the first energy feedback path is connected; when the controllable switch element is closed, the second energy feedback path is connected.

[0013] In the energy feedback device of the magnetic levitation bearing system provided by the present invention, the monitoring module includes a voltage comparator, the first input terminal of the voltage comparator is connected to the magnetic levitation bearing system, the second input terminal of the voltage comparator is connected to a reference voltage unit, and the output terminal of the voltage comparator is connected to the motor controller.

[0014] In the energy feedback device of the magnetic levitation bearing system provided by the present invention, the reference voltage provided by the reference voltage unit is the stable operating voltage of the magnetic levitation bearing system.

[0015] The present invention also provides an energy feedback method for a magnetic levitation bearing system, applied to the energy feedback device of the aforementioned magnetic levitation bearing system, the method comprising:

[0016] If a mains power outage is detected, the magnetic levitation bearing system is powered through the first energy feedback path according to the first energy feedback voltage.

[0017] Monitor the bearing voltage of the magnetic levitation bearing system and determine whether the bearing voltage is not less than the stable operating voltage of the magnetic levitation bearing system;

[0018] If the bearing voltage is less than the stable operating voltage of the magnetic levitation bearing system, the first energy feedback voltage is adjusted to the second energy feedback voltage, and the magnetic levitation bearing system is powered through the second energy feedback path according to the second energy feedback voltage, wherein the second energy feedback voltage is less than the stable operating voltage and greater than the minimum input voltage of the magnetic levitation bearing system.

[0019] The present invention also provides a magnetic levitation system, including the energy feedback device of the magnetic levitation bearing system and the magnetic levitation bearing system described above, wherein the energy feedback device of the magnetic levitation bearing system is configured to perform the energy feedback method of the magnetic levitation bearing system described above.

[0020] This invention provides an energy feedback device, method, and magnetic levitation system for a magnetic levitation bearing system. The energy feedback device includes a first energy feedback path consisting of a motor, a controllable inverter module, a power supply module, and the magnetic levitation bearing system connected in sequence, and a second energy feedback path consisting of a motor, a controllable inverter module, a path switching module, and the magnetic levitation bearing system connected in sequence. When the mains power fails abnormally, the motor coasts to generate electrical energy feedback, which is transmitted to the magnetic levitation bearing system through the first energy feedback path according to the first energy feedback voltage. The bearing voltage of the magnetic levitation bearing system is detected in real time by a monitoring module. When the bearing voltage is lower than the stable operating voltage of the magnetic levitation bearing system, the first energy feedback voltage is lowered to the second energy feedback voltage, and the magnetic levitation bearing system is powered through the second energy feedback path. Although the second energy feedback voltage is lower than the stable operating voltage of the magnetic levitation bearing system, it is greater than the minimum input voltage of the magnetic levitation bearing system. Therefore, the magnetic levitation bearing system can still work normally, thereby maintaining the magnetic levitation bearing system in a working state, extending its working time, and ensuring that the rotor drops to zero speed. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of energy feedback in a conventional magnetic levitation bearing system.

[0023] Figure 2 This is a schematic diagram of the energy feedback device of the magnetic levitation bearing system according to an embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of the energy feedback device of a magnetic levitation bearing system according to another embodiment of the present invention;

[0025] Figure 4 This is a schematic flowchart illustrating the steps of the energy feedback method for a magnetic levitation bearing system according to an embodiment of the present invention.

[0026] Figure 5 This is a schematic flowchart of the energy feedback method for a magnetic levitation bearing system according to another embodiment of the present invention;

[0027] Figure 6 This is a logical schematic diagram of the energy feedback method of the magnetic levitation bearing system according to an embodiment of the present invention;

[0028] Explanation of reference numerals in the attached figures:

[0029] 10. Motor; 20. Motor controller; 30. Controllable inverter module; 40. Power supply module; 50. Monitoring module; 60. Path switching module; 70. Magnetic levitation bearing system. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] The directional terms used in this invention, such as "up," "down," "front," "back," "left," "right," "inner," "outer," and "side," are merely for reference to the accompanying drawings. Therefore, the directional terms used are for illustrating and understanding this invention, and not for limiting it. Furthermore, in the drawings, structures that are similar or identical are indicated by the same reference numerals.

[0032] To clearly explain the working principle of the embodiments of the present invention, a brief description of the energy feedback method of existing magnetic levitation bearing systems is first given. Furthermore, for the sake of consistency in terminology, all parameters in the embodiments of the present invention are explained: V1 is the DC bus voltage / energy feedback voltage; V2 is the bearing voltage; Va is the minimum input voltage of the bearing controller power supply; Vb is the minimum input voltage of the bearing controller; R is the rotor speed; the voltage magnitude relationship is: V1 > Va > V2 > Vb.

[0033] Figure 1This diagram illustrates the energy feedback mechanism of a magnetic levitation bearing system in the event of a mains power outage. During normal operation, if the mains power supply suddenly fails, the motor controller detects the outage and initiates energy feedback. The energy feedback path is shown by the dotted line in the diagram. The motor coasts, generating electrical energy, which the motor controller feeds back to the DC bus via the inverter module. The energy feedback voltage is set to V1 (e.g., 450V), which is greater than the minimum required input voltage Va (e.g., 400V) for the bearing controller. The bearing controller can then continue operating, outputting a voltage V2 (e.g., 300V), which is the bearing voltage. Similarly, this voltage is greater than the minimum required input voltage Vb (e.g., 200V) for the bearing controller, allowing it to continue operating and maintain rotor levitation to prevent it from falling. However, this is an ideal scenario. In actual operation, the following problems exist: First, under certain conditions of high inertia or special operating conditions, the motor rotor may still coast, but the energy is insufficient to maintain the feedback voltage V1, causing V1 to fall below Va. This causes the bearing controller to stop operating, resulting in a power outage and the rotor falling at high speed (rotational fall), causing wear and damage to the magnetic levitation system. Second: During the energy feedback process, the feedback voltage fluctuates, which may cause damage or abnormality to the bearing controller power supply, resulting in a power outage of the bearing controller, causing the rotor to fall at high speed and causing serious damage.

[0034] To address the problem of high-speed rotor drop damaging the magnetic levitation system when power is lost, this invention proposes an energy feedback device, method, and magnetic levitation system for a magnetic levitation bearing system, as detailed below.

[0035] Please see Figure 2 , Figure 2 An energy feedback device for a magnetic levitation bearing system 70 according to an embodiment of the present invention includes: a motor 10, a motor controller 20, a controllable inverter module 30, a power supply module 40, a monitoring module 50, and a path switching module 60; the motor 10, the controllable inverter module 30, the power supply module 40, and the magnetic levitation bearing system 70 are sequentially connected and configured as a first energy feedback path; the motor 10, the controllable inverter module 30, the path switching module 60, and the magnetic levitation bearing system 70 are sequentially connected and configured as a second energy feedback path; the motor controller 20 is connected to the monitoring module 50, the path switching module 60, and the controllable inverter module 30, and the monitoring module 50 is connected to the magnetic levitation bearing system 70.

[0036] Specifically, during normal operation, the mains power is rectified by the uncontrolled rectifier module and delivered to the DC bus. The controllable inverter module 30 inverts the DC power on the DC bus into AC power to supply the motor 10, thus powering the motor 10. When the mains power suddenly fails, the motor controller 20 detects the power failure through the detection circuit and controls the controllable inverter module 30 to convert the energy of the motor 10 during idle into electrical energy, which is then fed back to the DC bus and transmitted to the magnetic levitation bearing system 70 through the energy feedback path, enabling the magnetic levitation bearing system 70 to continue operating.

[0037] The energy feedback path consists of two paths: a first energy feedback path and a second energy feedback path. The first energy feedback path starts from the motor 10, passes sequentially through the controllable inverter module 30 and the power supply module 40, and finally reaches the magnetic levitation bearing system 70. In the first energy feedback path, the power supply module 40 draws power from the DC bus to maintain normal operation and then supplies electrical energy to the magnetic levitation bearing system 70. The DC bus voltage, which is also the energy feedback voltage, is first supplied to the power supply module 40, and then the power supply module 40 outputs voltage to the magnetic levitation bearing system 70.

[0038] The second energy feedback path starts from motor 10, passes through controllable inverter module 30 and path switching module 60, and ends at magnetic levitation bearing system 70. Unlike the first energy feedback path, which bypasses power module 40 and connects directly to magnetic levitation bearing system 70 via path switching module 60, the second energy feedback path allows the energy feedback voltage to be directly output to magnetic levitation bearing system 70. When the energy feedback voltage V1 drops to V1', which is insufficient to maintain the minimum input voltage Va of power module 40 (V1' < Va), the system switches to the second energy feedback path. The energy feedback voltage V1' directly supplies the magnetic levitation bearing system 70. Although V1' is less than Va, it is still greater than the minimum input voltage Vb of magnetic levitation bearing system 70, allowing it to continue operating normally. In contrast, when V1' < Va in the first energy feedback path, power module 40 stops working, and magnetic levitation bearing system 70 experiences a direct power loss and rotor speed drop. The second energy feedback path extends the operating time of magnetic levitation bearing system 70.

[0039] The monitoring module 50 is used to monitor the bearing voltage of the magnetic levitation bearing system 70 in real time, and uses this to determine the operating status of the power supply module 40 and feed it back to the motor controller 20. The purpose of the monitoring module 50 in determining the operating status of the power supply module 40 by monitoring the bearing voltage in real time is to identify when the power supply module 40 stops working, and to feed back to the motor controller 20 before the power supply module 40 stops working. The motor controller 20 then promptly controls the path switching module 60 to switch the energy feedback path, so that the magnetic levitation bearing system 70 will not lose power due to the power supply module 40 losing power, and the path is switched in time to improve the reliability of the magnetic levitation bearing system 70.

[0040] The motor controller 20 mainly functions as a control component. On one hand, the motor controller 20 detects whether there is an abnormal power outage in the mains power supply based on the detection circuit. When there is an abnormal power outage, it controls the controllable inverter module 30 to perform energy feedback and sets the corresponding energy feedback voltage to convert the energy generated by the motor 10 during coasting into electrical energy to be fed back to the DC bus. The electrical energy is first fed back to the magnetic levitation bearing system 70 through the first energy feedback path. On the other hand, it outputs control commands to the path switching module 60 to control it to perform path switching, switching from the first energy feedback path to the second energy feedback path. Furthermore, it receives information from the monitoring module 50 and outputs path switching commands to the path switching module 60 based on the feedback information.

[0041] By implementing this embodiment, the energy feedback transmission path is switched according to the monitored bearing voltage, the feedback voltage is reduced, the working time of the bearing controller is extended, the rotor zero speed drop is achieved, rotor wear / damage is avoided, and the reliability of the magnetic levitation bearing system 70 is greatly improved.

[0042] In one embodiment, the controllable inverter module 30 is connected to the mains power via a DC bus, and the power supply module 40 is connected to both the DC bus and the magnetic levitation bearing system 70. Specifically, the mains power inputs AC power to the magnetic levitation system, which is converted into DC power by an uncontrolled rectifier module and input to the DC bus. The controllable inverter then converts the DC voltage back into AC power to supply the motor 10. When the mains power fails abnormally, the energy generated by the motor 10 during coasting is fed back to the DC bus via the controllable inverter module 30, and then fed back to the power supply module 40 to maintain the rotor's levitation, thus realizing the energy feedback of the first energy feedback path.

[0043] In one embodiment, the path switching module 60 is connected in parallel with the power supply module 40. Specifically, the magnetic levitation bearing system 70 includes a bearing controller and a bearing, and the power supply module 40 is the power supply for the bearing controller, which is connected to the bearing controller. To achieve the switching of the second energy feedback path, this embodiment connects the path switching module 60 in parallel with the bearing controller power supply. Thus, when the energy feedback voltage is insufficient to maintain the operation of the bearing controller power supply, the bearing controller power supply stops working, which is equivalent to an open circuit. Since the path switching module 60 is connected in parallel with the bearing controller power supply, the electrical energy on the DC bus can be directly supplied to the magnetic levitation bearing system 70 through the path switching module 60, avoiding the rotor falling at high speed due to the bearing controller power supply failure. This realizes the energy feedback of the second energy feedback path and solves the problem of the rotor falling at high speed due to the abnormal bearing controller power supply during power failure.

[0044] In this embodiment, the path switching module 60 includes a controllable switching element, which has a first terminal, a second terminal, and a third terminal. The first terminal and the second terminal are respectively connected to the two ends of the power supply module 40, and the third terminal is connected to the motor controller 20. Specifically, the controllable switching element is a controllable contactor Q1. The control terminal of the controllable contactor Q1, i.e., the third terminal, is connected to the motor controller 20, and the motor controller 20 controls the open and closed states of the controllable contactor Q1. The input terminal and the output terminal of the controllable switching element are the first terminal and the second terminal, respectively. The first terminal is connected between the DC bus and the power supply module 40, and the second terminal is connected between the power supply module 40 and the magnetic levitation bearing system 70. This achieves parallel connection between the controllable switching element and the power supply module 40, and the controllable switching element directly connects the DC bus and the magnetic levitation bearing system 70. When the power supply module 40 stops working, energy can be supplied to the magnetic levitation bearing system 70 through the second energy feedback path formed by the controllable switching element.

[0045] Furthermore, when the controllable switching element is open, the first energy feedback path is activated; when the controllable switching element is closed, the second energy feedback path is activated. Specifically, when the controllable contactor Q1 is open, the first energy feedback path is activated, and the energy feedback voltage on the DC bus first supplies the bearing controller power supply, and then the bearing controller power supply supplies the magnetic levitation bearing system 70. Since the bearing controller power supply cannot maintain normal operation and is disconnected, the controllable contactor Q1 closes, switching to the second energy feedback path, and the energy feedback voltage on the DC bus directly supplies the magnetic levitation bearing system 70. Thus, the switching of the energy feedback path can be controlled by the opening and closing of the controllable switching element.

[0046] In one embodiment, the monitoring module 50 includes a voltage comparator. The first input terminal of the voltage comparator is connected to the magnetic levitation bearing system 70, the second input terminal is connected to a reference voltage unit, and the output terminal is connected to the motor controller 20. Specifically, the first input terminal of the monitoring module 50 serves as a voltage detection terminal to collect the bearing voltage of the magnetic levitation bearing system 70 in real time. The second input terminal of the monitoring module 50 serves as a reference voltage acquisition terminal connected to a reference voltage unit. This reference voltage power supply provides a stable reference voltage, specifically the stable operating voltage of the magnetic levitation bearing system 70. The voltage comparator compares the bearing voltage with the stable operating voltage of the magnetic levitation bearing system 70 to output a feedback signal to the motor controller 20. The motor controller 20 then controls the path switching module 60 to switch the energy feedback path. The feedback signal is output only when the bearing voltage is less than the stable operating voltage of the magnetic levitation bearing system 70. Because the energy feedback voltage provided on the DC bus may decrease or fluctuate, the bearing controller power supply may struggle to maintain normal operation, leading to a lack of stable and effective power supply to the magnetic levitation bearing system 70. This ultimately results in changes in the bearing voltage of the magnetic levitation bearing system 70. Therefore, this embodiment uses real-time acquisition of the bearing voltage to determine the operating status of the bearing controller power supply. When the bearing voltage is lower than the stable operating voltage of the magnetic levitation bearing system 70, it indicates that the bearing controller power supply is unable to provide a stable operating voltage to the magnetic levitation bearing system 70. At this time, a feedback signal is promptly output to the motor controller 20, notifying the motor controller 20 to switch the energy feedback path in a timely manner, thereby improving system reliability.

[0047] Reference Figure 5 This invention also proposes an energy feedback method for a magnetic levitation bearing system, applicable to the energy feedback device of the aforementioned magnetic levitation bearing system. Figure 5 This is a flowchart illustrating the steps of an energy feedback method for a magnetic levitation bearing system according to an embodiment of the present invention, wherein the steps include: S110-S130.

[0048] S110. If a mains power failure is detected, power is supplied to the magnetic levitation bearing system through the first energy feedback path according to the first energy feedback voltage.

[0049] S120. Monitor the bearing voltage of the magnetic levitation bearing system and determine whether the bearing voltage is not less than the stable operating voltage of the magnetic levitation bearing system.

[0050] S130. If the bearing voltage is less than the stable operating voltage of the magnetic levitation bearing system, the first energy feedback voltage is adjusted to the second energy feedback voltage, and the magnetic levitation bearing system is powered through the second energy feedback path according to the second energy feedback voltage, wherein the second energy feedback voltage is less than the stable operating voltage and greater than the minimum input voltage of the magnetic levitation bearing system.

[0051] Referring to the figure, in this embodiment, both the first energy feedback voltage and the second energy feedback voltage are configured by the motor controller. For ease of explanation, the first energy feedback voltage is referred to as V1 and the second energy feedback voltage is referred to as V1' in the following text. An example will be used to illustrate this.

[0052] When a mains power outage is detected, energy feedback is initiated. The energy feedback voltage is set to V1 (e.g., 450V). Energy transfer and conversion proceed according to the first energy feedback path, i.e., a stable bearing voltage V2 (e.g., 300V) is output from the bearing controller power converter to power the bearing controller, which maintains rotor suspension. Simultaneously, the motor controller collects and judges the bearing voltage V2 value in real time through the bearing voltage monitoring module. When it is determined that the collected rotational speed is not 0 and the bearing voltage V2 < 300V, the motor controller controls Q1 in the energy feedback path switching module to close, switching to the second energy feedback path. At the same time, the energy feedback voltage V1' is adjusted to 250V, extending the motor energy feedback time, and the energy feedback voltage V1' is directly supplied to the bearing controller, allowing the bearing controller to continue operating and keeping the rotor suspended until the rotational speed R drops to 0, i.e., the rotor stops. It should be noted that after switching to the second energy feedback path, the energy feedback voltage V1' is reduced. At this time, V1' < Va, and the bearing controller power supply cannot work, which is equivalent to being disconnected. However, when the energy feedback voltage V1' is adjusted to 250V, which is greater than Vb, the bearing controller can still work normally.

[0053] It is important to emphasize that the inventive concept of this invention lies in the coordination of adjusting the energy feedback voltage and switching the energy feedback path. When the bearing controller power supply is found to be unstable by monitoring the bearing voltage, the energy feedback path is switched in a timely manner and the energy feedback voltage is lowered simultaneously. This ensures that the bearing controller can continue to operate even after the power supply to the bearing controller is lost, extending the operating time of the bearing controller until the rotor reaches zero speed.

[0054] In one embodiment, such as Figure 6 As shown, the method further includes steps S140-S150.

[0055] S140. If the bearing voltage is not less than the stable operating voltage of the magnetic levitation bearing system, continue to supply power to the magnetic levitation bearing system through the first energy feedback path according to the first energy feedback voltage.

[0056] S150. Determine whether the motor speed is zero; if the motor speed is not zero, return to the step of monitoring the bearing voltage of the magnetic levitation bearing system and determining whether the bearing voltage is not less than the stable operating voltage of the magnetic levitation bearing system.

[0057] In this embodiment, the bearing voltage of the magnetic levitation bearing system is monitored by a monitoring module and compared with the stable operating voltage of the magnetic levitation bearing system. If the bearing voltage is greater than or equal to the stable operating voltage of the magnetic levitation bearing system, it indicates that the bearing control power supply is working normally and can maintain the normal operation of the bearing controller. Therefore, the first energy feedback path continues to provide power. At the same time, the motor speed is collected to determine whether the motor speed is zero. If the motor speed is zero, energy feedback is stopped, and the rotor drops to zero speed, which will not damage the magnetic levitation bearing system. If the motor speed is not zero, the process returns to step S120 to continue monitoring the bearing voltage and constantly monitor the operating status of the bearing control power supply.

[0058] This embodiment adjusts the energy feedback voltage based on the monitored bearing voltage and rotation speed, and switches the energy transfer path to extend the working time of the magnetic levitation bearing system. This solves the problem of insufficient energy feedback time, rotor rotation and drop, which leads to rotor and bearing wear or even damage, and achieves rotor zero-speed drop.

[0059] This invention also provides a magnetic levitation system, including the energy feedback device of the magnetic levitation bearing system described above and the magnetic levitation bearing system itself. The energy feedback device of the magnetic levitation bearing system is configured to execute the energy feedback method of the magnetic levitation bearing system described above. The energy feedback device and energy feedback method of the magnetic levitation bearing system have been described in detail in the above embodiments, and for the sake of brevity, will not be repeated here.

[0060] By implementing this embodiment, a bearing voltage monitoring module and an energy feedback path switching module are added. The feedback voltage is adjusted according to the monitored bearing voltage and speed, and the energy transfer path is switched to extend the working time of the bearing controller, realize the rotor zero speed drop, solve the problem of rotor high speed drop caused by abnormal power supply of bearing controller under impact, and improve system reliability.

[0061] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An energy feedback device for a magnetic bearing system, characterized by, Comprise: a motor, a motor controller, a controllable inverter module, a power module, a monitoring module and a path switching module; the motor, the controllable inverter module, the power module and the magnetic suspension bearing system are sequentially connected and configured as a first energy feedback path; the motor, the controllable inverter module, the path switching module and the magnetic suspension bearing system are sequentially connected and configured as a second energy feedback path; the motor controller is connected with the monitoring module, the path switching module and the controllable inverter module, and the monitoring module is connected with the magnetic suspension bearing system.

2. The energy feedback device of claim 1, wherein, The controllable inverter module is connected with the mains through a DC bus, and the power module is connected with the DC bus and the magnetic suspension bearing system respectively.

3. The energy feedback device according to claim 1 or 2, characterized in that, The path switching module is connected with the power module in parallel.

4. The energy feedback device of claim 3, wherein, The path switching module comprises a controllable switching element, the controllable switching element comprises a first end, a second end and a third end, the first end and the second end are connected with two ends of the power module respectively, and the third end is connected with the motor controller.

5. The energy feedback device of claim 4, wherein, When the controllable switching element is open, the first energy feedback path is turned on; when the controllable switching element is closed, the second energy feedback path is turned on.

6. The energy feedback device of claim 1, wherein, The monitoring module comprises a voltage comparator, a first input end of the voltage comparator is connected with the magnetic suspension bearing system, a second input end of the voltage comparator is connected with a reference voltage unit, and an output end of the voltage comparator is connected with the motor controller.

7. The energy feedback device of claim 6, wherein, The reference voltage provided by the reference voltage unit is the stable working voltage of the magnetic suspension bearing system.

8. An energy feedback method for a magnetic bearing system, characterized by, The energy feedback device applied to the magnetic suspension bearing system of any one of claims 1-6, the method comprises: if the mains power is detected to be off, the magnetic suspension bearing system is powered according to the first energy feedback voltage through the first energy feedback path; monitoring the bearing voltage of the magnetic suspension bearing system and determining whether the bearing voltage is not less than the stable working voltage of the magnetic suspension bearing system; if the bearing voltage is less than the stable working voltage of the magnetic suspension bearing system, adjusting the first energy feedback voltage to a second energy feedback voltage, and powering the magnetic suspension bearing system according to the second energy feedback voltage through the second energy feedback path, wherein the second energy feedback voltage is less than the stable working voltage and greater than the minimum input voltage of the magnetic suspension bearing system.

9. The method of claim 8, wherein, The method further comprises: if the bearing voltage is not less than the stable working voltage of the magnetic suspension bearing system, maintaining the powering of the magnetic suspension bearing system according to the first energy feedback voltage through the first energy feedback path; determining whether the rotating speed of the motor is zero; if the rotating speed of the motor is not zero, returning to the step of monitoring the bearing voltage of the magnetic suspension bearing system and determining whether the bearing voltage is not less than the stable working voltage of the magnetic suspension bearing system.

10. A magnetic levitation system, characterized by, The energy feedback device of the magnetic suspension bearing system and the magnetic suspension bearing system comprising the energy feedback device of the magnetic suspension bearing system and the magnetic suspension bearing system of any one of claims 1-7, the energy feedback device of the magnetic suspension bearing system is configured to execute the energy feedback method of the magnetic suspension bearing system of any one of claims 8-9.

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