CN115264976A

CN115264976A - Magnetic suspension centrifuge, control method and device thereof and storage medium

Info

Publication number: CN115264976A
Application number: CN202210821731.7A
Authority: CN
Inventors: 李燕; 张统世; 于安波
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2022-07-13
Filing date: 2022-07-13
Publication date: 2022-11-01
Anticipated expiration: 2042-07-13
Also published as: CN115264976B

Abstract

The invention discloses a control method and a control device of a magnetic suspension centrifuge, the magnetic suspension centrifuge and a storage medium, wherein the method comprises the following steps: under the vector electric control mode, the rotating speed reference value of the rotating speed ring is set to be a set rotating speed value; if a magnetic bearing fault signal is received, the control working mode is switched from the vector electric control mode to the full-switch vector braking control mode; identifying the rotating speed of the magnetic suspension motor to obtain a rotating speed identification value; if a magnetic bearing fault recovery signal is received, the control working mode is switched from a full-switch vector braking control mode to a vector electric control mode; and under the vector electric control mode, the rotating speed reference value of the rotating speed ring is gradually changed to a set rotating speed value on the basis of the rotating speed identification value, so that the magnetic suspension motor is restarted. According to the scheme, the magnetic suspension motor is restarted from the identified rotating speed during fault recovery after being stopped, so that the restarting time can be reduced, and the uninterrupted operation requirement of the magnetic suspension centrifugal machine is met.

Description

Magnetic suspension centrifuge, control method and device thereof and storage medium

Technical Field

The invention belongs to the technical field of magnetic suspension, and particularly relates to a control method and device of a magnetic suspension centrifuge, the magnetic suspension centrifuge and a storage medium, in particular to a method and device for rapidly restarting a magnetic suspension motor in the magnetic suspension centrifuge (such as a magnetic suspension refrigeration centrifuge), the magnetic suspension centrifuge and the storage medium.

Background

The magnetic suspension motor has the characteristics of no oil, no friction and the like, can run at high speed and high efficiency, and is widely applied to a refrigeration centrifuge (namely a refrigeration centrifugal compressor). Load in the refrigerating centrifuge is random and variable, airflow impact is strong, magnetic bearing protection shutdown is easily caused when impact is serious, but for some special application occasions, such as a data machine room and an all-weather factory, a unit (namely, the unit where the refrigerating centrifuge is located) is required to be capable of refrigerating uninterruptedly, at the moment, the unit (namely, the unit where the refrigerating centrifuge is located) is required to be capable of restarting quickly after protection, and the method in the related scheme is that a standby unit (namely, the unit where the refrigerating centrifuge is located) is restarted from zero speed after shutdown is complete, the restarting time is long, and the requirement of uninterrupted operation of the unit (namely, the unit where the refrigerating centrifuge is located) cannot be met.

The above is only for the purpose of assisting understanding of the technical aspects of the present invention, and does not represent an admission that the above is prior art.

Disclosure of Invention

The invention aims to provide a control method and a control device of a magnetic suspension centrifuge, the magnetic suspension centrifuge and a storage medium, which are used for solving the problems that after the magnetic suspension centrifuge (such as a magnetic suspension refrigeration centrifuge) is protected and a magnetic suspension motor is stopped, the magnetic suspension motor is restarted from zero speed to prolong the restarting time and cannot meet the uninterrupted operation requirement of the magnetic suspension centrifuge (such as the magnetic suspension refrigeration centrifuge), and the restarting time of the magnetic suspension motor is reduced by starting the rotation speed identified when the magnetic suspension motor recovers from the fault after the magnetic suspension centrifuge (such as the magnetic suspension refrigeration centrifuge) is protected and the magnetic suspension centrifuge (such as the magnetic suspension refrigeration centrifuge) is stopped, so that the uninterrupted operation requirement of the magnetic suspension centrifuge (such as the magnetic suspension refrigeration centrifuge) can be met.

The invention provides a control method of a magnetic suspension centrifuge, wherein the magnetic suspension centrifuge is provided with a magnetic suspension motor, a bearing controller and a frequency converter; the outer ring of the frequency converter is provided with a rotating speed ring and a voltage ring, the outer ring of the frequency converter can control the rotating speed ring and the voltage ring to work in a switching mode, the working mode of the outer ring of the frequency converter is a vector electric control mode when the rotating speed ring works, and the working mode of the outer ring of the frequency converter is a full-switch vector braking control mode when the voltage ring works; the control method of the magnetic suspension centrifuge comprises the following steps: under the condition of normal operation after the magnetic suspension motor is started, controlling the working mode of the outer ring of the frequency converter to be the vector electric control mode; under the vector electric control mode, the rotating speed reference value of the rotating speed ring is set to be a set rotating speed value; determining whether a magnetic bearing fault signal sent by the magnetic bearing controller is received; the magnetic bearing fault signal is a signal for generating a magnetic bearing impact fault of the magnetic suspension motor; if a magnetic bearing fault signal sent by the magnetic bearing controller is received, controlling the working mode of an outer ring of the frequency converter to be switched from the vector electric control mode to the full-switch vector braking control mode; identifying the rotating speed of the magnetic suspension motor in the braking process of the magnetic suspension motor in the full-switching vector braking control mode to obtain a rotating speed identification value; determining whether a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received after controlling an outer ring of the frequency converter to work in the full-switching vector brake control mode; the magnetic bearing fault recovery signal is a recovery signal of a magnetic bearing impact fault of the magnetic suspension motor; if a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received, controlling the working mode of the outer ring of the frequency converter to be switched from the full-switch vector braking control mode to the vector electric control mode; and under the vector electric control mode, gradually adjusting the rotating speed reference value of the rotating speed ring to the set rotating speed value on the basis of the rotating speed identification value so as to restart the magnetic suspension motor.

In some embodiments, further comprising at least one of: after determining whether a magnetic bearing fault signal sent by the magnetic bearing controller is received, if the magnetic bearing fault signal is not received, continuously controlling the outer ring of the frequency converter to work in the vector motor control mode; and/or after determining whether a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received, if the magnetic bearing fault recovery signal sent by the magnetic bearing controller is not received, continuously controlling the working mode of the outer ring of the frequency converter to be the full-switching vector braking control mode; continuously identifying the rotating speed of the magnetic suspension motor in the braking process of the magnetic suspension motor in the full-switch vector braking control mode to obtain a rotating speed identification value; and controlling the bus voltage of the frequency converter to be boosted to a set voltage value in the braking process of the magnetic suspension motor in the full-switching vector braking control mode.

In some embodiments, the outer loop of the frequency converter further has a mode switching unit; the mode switching unit can enable the working mode mark of the outer ring of the frequency converter to be a first set mark in the vector electric control mode; and under the full-switching vector braking control mode, the working mode mark of the outer ring of the frequency converter is made to be a second set mark.

In some embodiments, wherein determining whether a magnetic bearing fault signal sent by the magnetic bearing controller is received comprises: determining whether the working mode flag of the outer ring of the frequency converter is changed from a first set flag to a second set flag; if the working mode mark of the outer ring of the frequency converter is changed from a first set mark to a second set mark, determining that a magnetic bearing fault signal sent by the magnetic bearing controller is received; if the working mode mark of the outer ring of the frequency converter is still the first set mark, determining that the magnetic bearing fault signal sent by the magnetic bearing controller is not received; and/or, determining whether a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received, comprising: determining whether the working mode flag of the outer ring of the frequency converter is changed from a second setting flag to a first setting flag; if the working mode mark of the outer ring of the frequency converter is changed from the second setting mark to the first setting mark, determining that a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received; and if the working mode mark of the outer ring of the frequency converter is still the second set mark, determining that the magnetic bearing fault recovery signal sent by the magnetic bearing controller is not received.

In another aspect, the present invention provides a control apparatus for a magnetic suspension centrifuge, wherein the magnetic suspension centrifuge comprises a magnetic suspension motor, a bearing controller and a frequency converter; the outer ring of the frequency converter is provided with a rotating speed ring and a voltage ring, the outer ring of the frequency converter can control the rotating speed ring and the voltage ring to work in a switching mode, the working mode of the outer ring of the frequency converter is a vector electric control mode when the rotating speed ring works, and the working mode of the outer ring of the frequency converter is a full-switch vector braking control mode when the voltage ring works; the control device of the magnetic suspension centrifugal machine comprises: the control unit is configured to control the working mode of the outer ring of the frequency converter to be the vector electric control mode under the condition of normal operation after the magnetic suspension motor is started; under the vector electric control mode, the rotating speed reference value of the rotating speed ring is set to be a set rotating speed value; the control unit further configured to determine whether a magnetic bearing fault signal sent by the magnetic bearing controller is received; the magnetic bearing fault signal is a signal for generating a magnetic bearing impact fault of the magnetic suspension motor; the control unit is further configured to control the working mode of the outer ring of the frequency converter to be switched from the vector motor control mode to the full-switching vector brake control mode if a magnetic bearing fault signal sent by the magnetic bearing controller is received; identifying the rotating speed of the magnetic suspension motor in the braking process of the magnetic suspension motor in the full-switch vector braking control mode to obtain a rotating speed identification value; the control unit is further configured to determine whether a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received after controlling the outer loop of the frequency converter to operate in the full switching vector brake control mode; the magnetic bearing fault recovery signal is a recovery signal of the magnetic bearing impact fault of the magnetic suspension motor; the control unit is further configured to control the working mode of the outer ring of the frequency converter to be switched from the full-switching vector braking control mode to the vector motor control mode if a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received; and under the vector electric control mode, gradually adjusting the rotating speed reference value of the rotating speed ring to the set rotating speed value on the basis of the rotating speed identification value so as to restart the magnetic suspension motor.

In some embodiments, further comprising at least one of: the control unit is further configured to, after determining whether a magnetic bearing fault signal sent by the magnetic bearing controller is received, if the magnetic bearing fault signal is not received, continue to control the outer ring of the frequency converter to operate in the vector motor control mode; and/or the control unit is further configured to, after determining whether a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received, if the magnetic bearing fault recovery signal sent by the magnetic bearing controller is not received, continue to control the working mode of the outer ring of the frequency converter to be the full-switching vector brake control mode; continuously identifying the rotating speed of the magnetic suspension motor in the braking process of the magnetic suspension motor in the full-switch vector braking control mode to obtain a rotating speed identification value; and controlling the bus voltage of the frequency converter to be boosted to a set voltage value in the braking process of the magnetic suspension motor in the full-switching vector braking control mode.

In some embodiments, the outer loop of the frequency converter further has a mode switching unit; the mode switching unit can enable the working mode mark of the outer ring of the frequency converter to be a first set mark in the vector electric control mode; and under the full-switch vector braking control mode, enabling the working mode mark of the outer ring of the frequency converter to be a second set mark.

In some embodiments, wherein the control unit determining whether the magnetic bearing fault signal sent by the magnetic bearing controller is received comprises: determining whether the working mode flag of the outer ring of the frequency converter is changed from a first set flag to a second set flag; if the working mode mark of the outer ring of the frequency converter is changed from a first set mark to a second set mark, determining that a magnetic bearing fault signal sent by the magnetic bearing controller is received; if the working mode mark of the outer ring of the frequency converter is still the first set mark, determining that the magnetic bearing fault signal sent by the magnetic bearing controller is not received; and/or, the control unit determining whether a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received, comprising: determining whether the working mode flag of the outer ring of the frequency converter is changed from a second setting flag to a first setting flag; if the working mode mark of the outer ring of the frequency converter is changed from the second setting mark to the first setting mark, determining that a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received; and if the working mode mark of the outer ring of the frequency converter is still the second set mark, determining that the magnetic bearing fault recovery signal sent by the magnetic bearing controller is not received.

In accordance with another aspect of the present invention, there is provided a magnetic suspension centrifuge, including: the control device of the magnetic suspension centrifuge is described above.

In accordance with the above method, a further aspect of the present invention provides a storage medium, which includes a stored program, wherein when the program runs, a device in which the storage medium is located is controlled to execute the above control method for a magnetic suspension centrifuge.

Therefore, according to the scheme of the invention, under the condition that the frequency converter receives the impact fault signal of the magnetic suspension centrifuge, the magnetic suspension motor is subjected to full-switching vector modulation brake control, the damping of the magnetic bearing system is increased, and the rotating speed of the magnetic suspension motor is identified in real time; then, under the condition that a fault recovery signal of the impact fault of the magnetic suspension centrifuge is received by the frequency converter, the magnetic suspension motor has rotating speed (namely non-zero rotating speed) at the starting moment of restarting the magnetic suspension motor, the target rotating speed of the magnetic suspension motor changes on the basis of the rotating speed obtained by identifying when the impact fault of the magnetic suspension centrifuge recovers, and the rapid restarting of the magnetic suspension motor with the speed is realized, so that after the magnetic suspension centrifuge (such as a magnetic suspension refrigeration centrifuge) is stopped due to the protection of the magnetic suspension centrifuge, the rotating speed identified when the magnetic suspension motor recovers from the fault starts restarting, the restarting time of the magnetic suspension motor is reduced, and the uninterrupted operation requirement of the magnetic suspension centrifuge (such as a magnetic suspension refrigeration centrifuge) can be met.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the invention.

The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.

Drawings

FIG. 1 is a schematic flow chart of an embodiment of a control method of a magnetic levitation centrifuge of the present invention;

FIG. 2 is a schematic flow chart illustrating one embodiment of the method of the present invention for determining whether a magnetic bearing fault signal sent by the magnetic bearing controller is received;

FIG. 3 is a schematic flow chart illustrating one embodiment of the method of the present invention for determining whether a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received;

FIG. 4 is a schematic structural diagram of an embodiment of a magnetic levitation motor control system;

FIG. 5 is a schematic diagram illustrating a switching process of an embodiment of the operation mode of the frequency converter;

FIG. 6 is a control block diagram of an embodiment of a fast restart apparatus for a magnetic levitation motor in a magnetic levitation refrigeration centrifuge;

fig. 7 is a schematic flow chart of an embodiment of a method for rapidly restarting a magnetic levitation motor in a magnetic levitation refrigeration centrifuge.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the specific embodiments of the present invention and the accompanying drawings. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

According to an embodiment of the present invention, a control method of a magnetic suspension centrifuge is provided, as shown in fig. 1, which is a schematic flow chart of an embodiment of the method of the present invention. The magnetic suspension centrifugal machine is provided with a magnetic suspension motor, a bearing controller and a frequency converter. Of course, the magnetic levitation centrifuge also has an inverter, with which the bearing controller can communicate, which is arranged between the frequency converter and the magnetic levitation motor. The outer loop of converter has rotational speed ring and voltage ring, the outer loop of converter can control the rotational speed ring with voltage ring switchingly works the rotational speed ring during operation the mode of operation of the outer loop of converter is vector electric control mode the voltage ring during operation the mode of operation of the outer loop of converter is full switch vector braking control mode, and wherein, the rotational speed ring is the rotational speed outer loop, and the voltage ring is the busbar voltage outer loop.

Fig. 4 is a schematic structural diagram of an embodiment of a magnetic levitation motor control system. The magnetic suspension motor control system comprises a magnetic bearing controller and a frequency converter, wherein the magnetic bearing controller is responsible for controlling a magnetic bearing, so that a rotating shaft of a magnetic suspension motor is stably suspended at a reference position. The frequency converter is used for driving the magnetic suspension motor, and the magnetic suspension motor rotates at a set rotating speed after the rotating shaft is suspended stably. The magnetic bearing controller and the frequency converter transmit key signals in a communication mode, and the key signals comprise a fault occurrence signal and a fault recovery signal of the magnetic bearing impact fault.

In some embodiments, the outer ring of the frequency converter further has a mode switching unit. Specifically, the outer ring control part of the frequency converter is provided with an outer ring control unit and a mode switching unit, and the outer ring control unit is provided with a rotating speed outer ring control unit and a bus voltage outer ring control unit. That is to say, the frequency converter is provided with an outer ring control unit, a mode switching unit and an inner ring control unit, wherein the mode switching unit is arranged between the outer ring control unit and the inner ring control unit, the outer ring control unit is a rotating speed ring and a voltage ring, and the inner ring control unit is a current ring.

The mode switching unit can make the working mode flag of the outer ring of the frequency converter be a first setting flag in the vector electric control mode. And under the full-switch vector braking control mode, enabling the working mode mark of the outer ring of the frequency converter to be a second set mark.

Fig. 5 is a schematic diagram illustrating a switching process of an embodiment of an operating mode of a frequency converter. As shown in fig. 5, the frequency converter includes two operation modes during the operation process, when the magnetic levitation motor is just started, the mode flag bit is 0, and the frequency converter is in an electric vector control (FOC) mode. When the magnetic suspension centrifuge is impacted by strong impact and has an impact fault, the magnetic bearing controller transmits an impact fault signal of the magnetic bearing (namely a fault occurrence signal of the impact fault of the magnetic bearing) to the frequency converter, the mode flag bit is changed into 1, and at the moment, the frequency converter enters a full-switching vector braking control mode to perform braking control on the magnetic suspension motor and increase the damping of the magnetic bearing. After the magnetic bearing is impacted and the magnetic bearing recovers stable suspension, the magnetic bearing impacts the fault recovery, the magnetic bearing controller transmits a fault recovery signal to the frequency converter, the mode flag bit is changed into 0 again, at the moment, the frequency converter enters a vector electric state again, and the secondary starting is completed, namely the restarting is carried out.

Fig. 6 is a control block diagram of an embodiment of a quick restart device of a magnetic suspension motor in a magnetic suspension refrigeration centrifuge. As shown in fig. 6, the device for rapidly restarting a magnetic suspension motor in a magnetic suspension refrigeration centrifuge mainly comprises: the device comprises an outer ring control unit, a mode switching unit, an inner ring control unit, an inverter and a magnetic levitation motor M. The inner ring control unit is provided with a coordinate transformation unit, a rotating speed and rotor position estimation unit and a PWM modulation unit. The outer ring control unit comprises a rotating speed outer ring unit and a bus voltage outer ring unit.

In the example shown in fig. 6, a speed outer loop unit, a mode switching unit, and fault communication operations (e.g., delivering magnetic bearing shock fault signals) of the magnetic bearing controller and frequency converter are added. The mode switching unit determines the value of the mode flag according to the received magnetic bearing impact fault signal, and the specific assignment manner is as shown in the example shown in fig. 5 and the description thereof.

In an aspect of the present invention, a method for controlling a magnetic levitation centrifuge includes: step S110 to step S150.

At step S110, on the side of the frequency converter, under the condition of normal operation after the magnetic suspension motor is started, controlling the working mode of the outer ring of the frequency converter to be the vector motor control mode, so that the rotation speed ring participates in the operation process of the magnetic suspension motor. And under the vector electric control mode, the rotating speed reference value of the rotating speed ring is set to be a set rotating speed value.

At step S120, on the frequency converter side, during normal operation of the magnetic levitation motor, it is determined whether a magnetic bearing fault signal sent by the magnetic bearing controller is received. The magnetic bearing fault signal is a signal for occurrence of a magnetic bearing impact fault of the magnetic suspension motor.

In some embodiments, a specific procedure of determining whether a magnetic bearing fault signal sent by the magnetic bearing controller is received at the frequency converter side in step S120, see the following exemplary description.

The specific process of determining whether to receive the magnetic bearing fault signal sent by the magnetic bearing controller in step S120 is further described below with reference to a flowchart of an embodiment of determining whether to receive the magnetic bearing fault signal sent by the magnetic bearing controller in the method of the present invention shown in fig. 2, including: step S210 to step S220.

Step S210, at the side of the frequency converter, determining whether the working mode flag of the outer ring of the frequency converter is changed from a first setting flag to a second setting flag.

Step S220, at the frequency converter side, if the working mode flag of the outer ring of the frequency converter has changed from the first setting flag to the second setting flag, it is determined that the magnetic bearing fault signal sent by the magnetic bearing controller has been received.

Step S230, at the frequency converter side, if the working mode flag of the outer ring of the frequency converter is still the first setting flag, that is, the working mode flag of the outer ring of the frequency converter is not changed from the first setting flag to the second setting flag, it is determined that the magnetic bearing fault signal sent by the magnetic bearing controller is not received.

Fig. 7 is a schematic flow chart of an embodiment of a method for rapidly restarting a magnetic levitation motor in a magnetic levitation refrigeration centrifuge. As shown in fig. 7, the method for rapidly restarting a magnetic levitation motor in a magnetic levitation refrigeration centrifuge includes:

step 1, the mode switching unit determines that the mode flag bit of the outer ring control unit is 0, and then step 2 is executed.

And 2, when the mode switching unit determines that the mode flag bit is 0, the magnetic suspension motor performs vector electric control, the outer ring control unit is a rotating speed outer ring unit, the rotating speed of the magnetic suspension motor is controlled to rotate according to a set rotating speed value, and then the step 3 is executed.

In the rotating speed outer ring unit, the outer ring input is a rotating speed reference value omega of the magnetic suspension motor and an actual rotating speed estimation value omega of the magnetic suspension motor obtained by the rotating speed and position estimation unit, the output of the rotating speed outer ring is a current vector, the current vector obtains a dq-axis current reference value according to MTPA (maximum torque current ratio control) or a flux weakening mode, and the dq-axis current reference value is the input of the inner ring control unit.

In step S130, on the frequency converter side, if a magnetic bearing fault signal sent by the magnetic bearing controller is received, the working mode of the outer ring of the frequency converter is controlled to be switched from the vector electric control mode to the fully-switched vector braking control mode, so that the voltage ring participates in the braking process of the magnetic suspension motor. And identifying the rotating speed of the magnetic suspension motor in the braking process of the magnetic suspension motor in the full-switch vector braking control mode to obtain a rotating speed identification value.

In some embodiments, after step S120, the method further includes: and on the side of the frequency converter, in the normal operation process of the magnetic suspension motor, after determining whether a magnetic bearing fault signal sent by the magnetic bearing controller is received or not, if the magnetic bearing fault signal is not received, continuously controlling the rotation speed ring to work, namely continuously controlling the outer ring of the frequency converter to work in the vector electric control mode so as to continuously enable the rotation speed ring to participate in the operation process of the magnetic suspension motor.

At step S140, on the frequency converter side, after controlling the outer ring of the frequency converter to operate in the full-switching vector brake control mode, it is determined whether a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received. The magnetic bearing fault recovery signal is a recovery signal of the magnetic bearing impact fault of the magnetic suspension motor.

In some embodiments, at the frequency converter side in step S140, a specific procedure of determining whether a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received is determined, see the following exemplary description.

The following further describes, with reference to a flowchart of an embodiment of determining whether to receive a magnetic bearing fault recovery signal sent by the magnetic bearing controller in the method of the present invention shown in fig. 3, a specific process of determining whether to receive a magnetic bearing fault recovery signal sent by the magnetic bearing controller in step S140, including: step S310 to step S330.

Step S310, at the side of the frequency converter, determining whether the working mode flag of the outer ring of the frequency converter is changed from the second setting flag to the first setting flag.

Step S320, at the frequency converter side, if the working mode flag of the outer ring of the frequency converter has changed from the second setting flag to the first setting flag, it is determined that the magnetic bearing fault recovery signal sent by the magnetic bearing controller has been received.

Step S330, determining, at the frequency converter side, that the magnetic bearing fault recovery signal sent by the magnetic bearing controller is not received if the working mode flag of the outer ring of the frequency converter is still the second setting flag, that is, the working mode flag of the outer ring of the frequency converter is not changed from the second setting flag to the first setting flag.

As shown in fig. 7, the method for rapidly restarting the magnetic levitation motor in the magnetic levitation refrigeration centrifuge further includes:

step 3, judging whether the mode flag bit is 1: if yes, executing step 4, otherwise returning to step 2.

Step 4, when the mode flag bit is 1, magnetically levitatesThe machine carries out a full-switch vector braking control mode, the outer ring control unit is a bus voltage outer ring unit, the bus voltage is controlled to be boosted to a set voltage value, and the outer ring input is a bus voltage set value u_dc* And the actually sampled bus voltage value u_dcThe output of the outer loop is a current vector as in the motoring mode, the current vector derives a dq-axis current reference value according to MTPA or flux weakening, the dq-axis current reference value is the input of the inner loop control unit, and then step 5 is executed.

In the whole control process, no matter the outer ring control unit is a rotating speed outer ring unit or a bus voltage outer ring unit, the inner ring control unit, the rotating speed and position estimation unit, the coordinate transformation unit and the PWM modulation unit are all in normal working states, so that the rotating speed and the rotor position of the magnetic suspension motor can be identified in real time in the braking process of the magnetic suspension motor.

Step 5, judging whether the mode flag bit is changed from 1 to 0: if yes, executing step 6, otherwise returning to step 3.

And 6, when the mode flag bit is changed from 1 to 0 again, the magnetic suspension motor starts to be restarted, and the rotating speed reference value omega of the magnetic suspension motor is increased or decreased on the basis of the rotating speed identified at the moment (namely the rotating speed of the magnetic suspension motor identified in real time in the braking process of the magnetic suspension motor), so that the current is prevented from sudden change at the restarting moment of the magnetic suspension motor.

In step S150, on the frequency converter side, if a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received, the working mode of the outer ring of the frequency converter is controlled to be switched from the full-switching vector braking control mode to the vector electric control mode, so that the rotation speed ring participates in the operation process of the magnetic levitation motor. And under the vector electric control mode, gradually adjusting the rotating speed reference value of the rotating speed ring to the set rotating speed value on the basis of the rotating speed identification value so as to restart the magnetic suspension motor.

The invention provides a rapid restart scheme of a magnetic suspension motor in a magnetic suspension refrigeration centrifuge.A magnetic bearing controller transmits a fault occurrence signal of the magnetic suspension centrifuge impact fault to a frequency converter in a rapid communication mode or other communication modes after the magnetic suspension centrifuge impact fault, the frequency converter performs full-switch vector modulation braking control on the magnetic suspension motor, the damping of a magnetic bearing system is increased, and the rotating speed and the rotor position of the magnetic suspension motor are identified in real time in the braking process of the magnetic suspension motor. In the braking process of the magnetic suspension motor, the voltage of the bus is controlled to be boosted to a set rotating speed value, and kinetic energy of the magnetic suspension motor is converted into electric energy to charge a bus capacitor and supply power to a bus load.

The fast communication mode is a communication mode. In the related scheme, the CAN communication is realized through software, other rapid software communication modes such as network communication and the like CAN also be adopted, and a hardware dry contact communication mode is also available.

In other communication modes, the magnetic bearing controller transmits a magnetic bearing impact fault signal to the frequency converter in an I/O dry contact mode between the magnetic bearing controller and the frequency converter, and the control effect of the scheme of the invention can also be achieved.

Furthermore, in the scheme of the invention, under the condition that the frequency converter performs full switching vector modulation braking control on the magnetic suspension motor, after the rotating shaft recovers stable suspension, the magnetic bearing controller transmits a fault recovery signal of impact fault of the magnetic suspension centrifuge to the frequency converter through a quick communication mode or other communication modes, the frequency converter performs vector electric control on the magnetic suspension motor, the magnetic suspension motor is restarted, the magnetic suspension motor has rotating speed (namely non-zero rotating speed) at the starting moment of restarting the magnetic suspension motor, the target rotating speed of the magnetic suspension motor is changed on the basis of the rotating speed identified when the impact fault of the magnetic suspension centrifuge recovers, the rapid restart of the magnetic suspension motor at the belt speed is realized, the control limitation of zero-speed restart of the magnetic suspension motor in the related scheme is broken, and the restart time is greatly reduced.

In some embodiments, after step S140, the method further includes: and on the side of the frequency converter, after controlling the outer ring of the frequency converter to work in the full-switching vector braking control mode, after determining whether a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received or not, and if the magnetic bearing fault recovery signal sent by the magnetic bearing controller is not received, continuously controlling the working mode of the outer ring of the frequency converter to be the full-switching vector braking control mode so as to continuously enable the voltage ring to participate in the braking process of the magnetic suspension motor. And continuously identifying the rotating speed of the magnetic suspension motor in the braking process of the magnetic suspension motor in the full-switch vector braking control mode to obtain a rotating speed identification value.

And controlling the bus voltage of the frequency converter to be boosted to a set voltage value in the braking process of the magnetic suspension motor in the full-switching vector braking control mode.

According to the scheme provided by the invention, when the magnetic suspension centrifuge is subjected to impact fault protection, the magnetic suspension motor is subjected to full-switch vector modulation brake control to increase the damping of a magnetic bearing system, so that a rotating shaft is quickly recovered to be stably suspended, the rotating shaft is quickly restarted on the basis of the rotating speed of the magnetic suspension motor after suspension is recovered, the magnetic suspension motor does not need to be restarted from zero speed after being completely stopped, the restarting time of the magnetic suspension motor is greatly shortened, and the uninterrupted refrigeration of the magnetic suspension centrifuge is realized. Therefore, the problem that the magnetic suspension centrifugal machine is long in restart time after fault protection is solved, the unit (namely the unit where the refrigerating centrifugal machine is located) is quickly restarted after short-time fault protection, and the application requirement of the unit (namely the unit where the refrigerating centrifugal machine is located) for uninterrupted operation is met.

Therefore, the scheme of the invention adopts a full-switching vector braking and bus voltage and current double-loop control mode to control the rotation restart of the magnetic suspension motor, brakes the magnetic suspension motor when the magnetic bearing has an impact fault and estimates the rotating speed and the rotor position of the magnetic suspension motor in real time, and controls the bus voltage to be at a set value during braking. When the fault is recovered, the rotating speed and the rotor position at the recovery moment are recorded, the rotating speed of the magnetic suspension motor is controlled to rotate according to the set rotating speed on the basis, the magnetic suspension motor enters an electric control state, the rapid restart after the magnetic bearing has an impact fault is realized, the restart time of the magnetic suspension motor is greatly shortened, and the uninterrupted refrigeration of the magnetic suspension centrifuge is realized.

By adopting the technical scheme of the embodiment, the frequency converter performs full-switching vector modulation braking control on the magnetic suspension motor under the condition of receiving the impact fault signal of the magnetic suspension centrifuge, so that the damping of the magnetic bearing system is increased, and the rotating speed of the magnetic suspension motor is identified in real time. Then, under the condition that a fault recovery signal of the magnetic suspension centrifuge impact fault is received by the frequency converter, the magnetic suspension motor has a rotating speed (namely a non-zero rotating speed) at the starting moment when the magnetic suspension motor is restarted, the target rotating speed of the magnetic suspension motor is changed on the basis of the rotating speed identified when the magnetic suspension centrifuge impact fault is recovered, and the magnetic suspension motor is rapidly restarted with the speed, so that the magnetic suspension centrifuge (such as a magnetic suspension refrigeration centrifuge) is protected to stop the magnetic suspension motor, the rotating speed identified when the magnetic suspension motor is recovered from the fault is restarted, the restarting time of the magnetic suspension motor is shortened, and the uninterrupted operation requirement of the magnetic suspension centrifuge (such as the magnetic suspension refrigeration centrifuge) can be met.

According to an embodiment of the invention, a control device of the magnetic suspension centrifuge corresponding to the control method of the magnetic suspension centrifuge is also provided. The magnetic suspension centrifugal machine is provided with a magnetic suspension motor, a bearing controller and a frequency converter. Of course, the magnetic levitation centrifuge also has an inverter, with which the bearing controller can communicate, which is arranged between the frequency converter and the magnetic levitation motor. The outer loop of converter has rotational speed ring and voltage ring, the outer loop of converter can control the rotational speed ring with voltage ring switchingly works the rotational speed ring during operation the mode of operation of the outer loop of converter is vector electric control mode the voltage ring during operation the mode of operation of the outer loop of converter is full switch vector braking control mode, and wherein, the rotational speed ring is the rotational speed outer loop, and the voltage ring is the busbar voltage outer loop.

The mode switching unit can make the working mode flag of the outer ring of the frequency converter be a first setting flag in the vector electric control mode. And under the full-switching vector braking control mode, the working mode mark of the outer ring of the frequency converter is made to be a second set mark.

Fig. 5 is a schematic diagram illustrating a switching process of an embodiment of an operating mode of a frequency converter. As shown in fig. 5, the frequency converter includes two operation modes in the operation process, when the magnetic levitation motor is just started, the mode flag bit is 0, and the frequency converter is in a motor vector control (FOC) mode. When the magnetic suspension centrifuge is impacted by strong impact and has an impact fault, the magnetic bearing controller transmits an impact fault signal of the magnetic bearing (namely a fault occurrence signal of the impact fault of the magnetic bearing) to the frequency converter, the mode flag bit is changed into 1, and at the moment, the frequency converter enters a full-switching vector braking control mode to perform braking control on the magnetic suspension motor and increase the damping of the magnetic bearing. After the magnetic bearing is impacted and the magnetic bearing recovers stable suspension, the magnetic bearing impacts the fault recovery, the magnetic bearing controller transmits a fault recovery signal to the frequency converter, the mode flag bit is changed into 0 again, at the moment, the frequency converter enters a vector electric state again, and the secondary starting is completed, namely the restarting is carried out.

In the example shown in fig. 6, a speed outer loop unit, a mode switching unit, and fault communication operations of the magnetic bearing controller and the frequency converter (e.g., transmitting a magnetic bearing shock fault signal) are added. The mode switching unit determines the value of the mode flag according to the received magnetic bearing impact fault signal, and the specific assignment manner is as shown in the example shown in fig. 5 and the description thereof.

In an aspect of the present invention, a control device for a magnetic levitation centrifuge includes: a control unit, such as a frequency converter controller.

And on the side of the frequency converter, a control unit is configured to control the working mode of an outer ring of the frequency converter to be the vector electric control mode under the condition of normal operation after the magnetic suspension motor is started, so that the rotating speed ring participates in the operation process of the magnetic suspension motor. And under the vector electric control mode, the rotating speed reference value of the rotating speed ring is set to be a set rotating speed value. The specific function and processing of the control unit are referred to in step S110.

On the frequency converter side, the control unit is further configured to determine whether a magnetic bearing fault signal sent by the magnetic bearing controller is received during normal operation of the magnetic levitation motor. The magnetic bearing fault signal is a signal for occurrence of a magnetic bearing impact fault of the magnetic suspension motor. The specific function and processing of the control unit are also referred to in step S120.

In some embodiments, on the frequency converter side, the control unit determining whether a magnetic bearing fault signal sent by the magnetic bearing controller is received comprises:

on the frequency converter side, the control unit is further configured to determine whether the operating mode flag of the outer ring of the frequency converter is changed from a first setting flag to a second setting flag. The specific functions and processes of the control unit are also referred to in step S210.

On the frequency converter side, the control unit is further configured to determine that a magnetic bearing fault signal sent by the magnetic bearing controller has been received if the operating mode flag of the outer ring of the frequency converter has changed from the first setting flag to the second setting flag. The specific function and processing of the control unit are also referred to in step S220.

On the frequency converter side, the control unit is further specifically configured to determine that the magnetic bearing fault signal sent by the magnetic bearing controller is not received if the operation mode flag of the outer ring of the frequency converter is still the first setting flag, that is, the operation mode flag of the outer ring of the frequency converter is not changed from the first setting flag to the second setting flag. The specific function and processing of the control unit are also referred to in step S230.

On the side of the frequency converter, the control unit is further configured to control the working mode of the outer ring of the frequency converter to be switched from the vector electric control mode to the full-switching vector braking control mode if a magnetic bearing fault signal sent by the magnetic bearing controller is received, so that the voltage loop participates in the braking process of the magnetic suspension motor. And identifying the rotating speed of the magnetic suspension motor in the braking process of the magnetic suspension motor in the full-switch vector braking control mode to obtain a rotating speed identification value. The specific function and processing of the control unit are also referred to in step S130.

In some embodiments, further comprising: on the side of the frequency converter, the control unit is further configured to, during normal operation of the magnetic levitation motor, after determining whether a magnetic bearing fault signal sent by the magnetic bearing controller is received, if the magnetic bearing fault signal is not received, continue to control the rotation speed loop to operate, that is, continue to control the outer loop of the frequency converter to operate in the vector motor control mode, so as to continue to enable the rotation speed loop to participate in the operation of the magnetic levitation motor.

On the frequency converter side, the control unit is further configured to determine whether a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received after controlling the outer loop of the frequency converter to operate in the full switching vector brake control mode. The magnetic bearing fault recovery signal is a recovery signal of the magnetic bearing impact fault of the magnetic suspension motor. The specific function and processing of the control unit are also referred to in step S140.

In some embodiments, on the frequency converter side, the control unit determining whether a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received comprises:

on the frequency converter side, the control unit is further configured to determine whether the operating mode flag of the outer ring of the frequency converter is changed from the second setting flag to the first setting flag. The specific functions and processes of the control unit are also referred to in step S310.

On the frequency converter side, the control unit is further specifically configured to determine that a magnetic bearing fault recovery signal sent by the magnetic bearing controller has been received if the operating mode flag of the outer ring of the frequency converter has changed from the second setting flag to the first setting flag. The specific functions and processes of the control unit are also referred to in step S320.

On the frequency converter side, the control unit is further specifically configured to determine that the magnetic bearing fault recovery signal sent by the magnetic bearing controller is not received if the operation mode flag of the outer ring of the frequency converter is still the second setting flag, that is, the operation mode flag of the outer ring of the frequency converter is not changed from the second setting flag to the first setting flag. The specific function and processing of the control unit are also referred to in step S330.

And 4, when the mode flag bit is 1, the magnetic suspension motor carries out a full-switch vector braking control mode, the outer ring control unit is a bus voltage outer ring unit and controls the bus voltage to be boosted to a set voltage value, and the outer ring input is a bus voltage set value u_dc* And the actually sampled bus voltage value u_dcThe output of the outer loop is a current vector as in the motoring mode, the current vector derives a dq-axis current reference value according to MTPA or flux weakening, the dq-axis current reference value is the input of the inner loop control unit, and then step 5 is executed.

On the side of the frequency converter, the control unit is further configured to control the working mode of the outer ring of the frequency converter to be switched from the full-switching vector braking control mode to the vector electric control mode if a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received, so that the rotating speed ring participates in the operation process of the magnetic suspension motor. And under the vector electric control mode, gradually adjusting the rotating speed reference value of the rotating speed ring to the set rotating speed value on the basis of the rotating speed identification value so as to restart the magnetic suspension motor. The specific function and processing of the control unit are also referred to in step S150.

The invention provides a rapid restarting scheme of a magnetic suspension motor in a magnetic suspension refrigeration centrifuge. In the braking process of the magnetic suspension motor, the voltage of the bus is controlled to be boosted to a set rotating speed value, and kinetic energy of the magnetic suspension motor is converted into electric energy to charge a bus capacitor and supply power to a bus load.

In some embodiments, further comprising: on the side of the frequency converter, the control unit is further configured to, after controlling the outer ring of the frequency converter to operate in the full-switching vector braking control mode, after determining whether a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received, if the magnetic bearing fault recovery signal sent by the magnetic bearing controller is not received, continue to control the operating mode of the outer ring of the frequency converter to be the full-switching vector braking control mode, so as to continue to enable the voltage ring to participate in the braking process of the magnetic levitation motor. And continuously identifying the rotating speed of the magnetic suspension motor in the braking process of the magnetic suspension motor in the full-switch vector braking control mode to obtain a rotating speed identification value.

Since the processes and functions implemented by the apparatus of this embodiment substantially correspond to the embodiments, principles and examples of the foregoing method, reference may be made to relevant descriptions in the foregoing embodiments for details that are not described in detail in the description of this embodiment, and further description is not provided herein.

By adopting the technical scheme of the invention, under the condition that the frequency converter receives the impact fault signal of the magnetic suspension centrifuge, the full-switching vector modulation brake control is carried out on the magnetic suspension motor, the damping of the magnetic bearing system is increased, and the rotating speed of the magnetic suspension motor is identified in real time; then, under the condition that a fault recovery signal of the impact fault of the magnetic suspension centrifuge is received by the frequency converter, the magnetic suspension motor has rotating speed (namely non-zero rotating speed) at the starting moment of restarting the magnetic suspension motor, the target rotating speed of the magnetic suspension motor changes on the basis of the rotating speed obtained by identification when the impact fault of the magnetic suspension centrifuge recovers, the rapid restarting of the magnetic suspension motor with speed is realized, the rapid restarting of a unit (namely the unit where the refrigeration centrifuge is located) after short-time fault protection is realized, and the application requirement of the unit (namely the unit where the refrigeration centrifuge is located) for uninterrupted operation is met.

According to an embodiment of the invention, a magnetic suspension centrifuge corresponding to a control device of the magnetic suspension centrifuge is also provided. The magnetic levitation centrifuge may include: the control device of the magnetic suspension centrifuge is described above.

Since the processing and functions of the magnetic suspension centrifuge of this embodiment are basically corresponding to the embodiments, principles and examples of the aforementioned apparatuses, the descriptions of this embodiment are not detailed herein, and refer to the related descriptions in the aforementioned embodiments, which are not repeated herein.

By adopting the technical scheme of the invention, under the condition that the frequency converter receives the impact fault signal of the magnetic suspension centrifuge, the full-switching vector modulation brake control is carried out on the magnetic suspension motor, the damping of the magnetic bearing system is increased, and the rotating speed of the magnetic suspension motor is identified in real time; then, under the condition that a fault recovery signal of the magnetic suspension centrifuge impact fault is received by the frequency converter, the magnetic suspension motor has a rotating speed (namely a non-zero rotating speed) at the starting moment when the magnetic suspension motor is restarted, and the target rotating speed of the magnetic suspension motor changes on the basis of the rotating speed obtained by identification when the magnetic suspension centrifuge impact fault is recovered, so that the magnetic suspension motor is quickly restarted with a high speed, the restarting time of the magnetic suspension motor is greatly shortened, and the uninterrupted refrigeration of the magnetic suspension centrifuge is realized.

According to an embodiment of the present invention, there is also provided a storage medium corresponding to a control method of a magnetic suspension centrifuge, the storage medium including a stored program, wherein when the program is executed, a device in which the storage medium is located is controlled to execute the above-described control method of a magnetic suspension centrifuge.

Since the processing and functions implemented by the storage medium of this embodiment substantially correspond to the embodiments, principles and examples of the foregoing method, reference may be made to relevant descriptions in the foregoing embodiments for details that are not described in detail in the description of this embodiment, and further description is not repeated here.

By adopting the technical scheme of the invention, under the condition that the frequency converter receives the impact fault signal of the magnetic suspension centrifuge, the full-switching vector modulation brake control is carried out on the magnetic suspension motor, the damping of the magnetic bearing system is increased, and the rotating speed of the magnetic suspension motor is identified in real time; then, under the condition that a fault recovery signal of the magnetic suspension centrifuge impact fault is received by the frequency converter, the magnetic suspension motor has a rotating speed (namely a non-zero rotating speed) at the starting moment when the magnetic suspension motor is restarted, the target rotating speed of the magnetic suspension motor changes on the basis of the rotating speed obtained by identification when the magnetic suspension centrifuge impact fault is recovered, the magnetic suspension motor is rapidly restarted at a speed, the magnetic suspension motor does not need to be restarted from the zero speed after being completely stopped, and the restarting time is shortened.

In summary, it is readily understood by those skilled in the art that the advantageous modes described above can be freely combined and superimposed without conflict.

The above description is only an example of the present invention, and is not intended to limit the present invention, and it is obvious to those skilled in the art that various modifications and variations can be made in the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. The control method of the magnetic suspension centrifugal machine is characterized in that the magnetic suspension centrifugal machine is provided with a magnetic suspension motor, a bearing controller and a frequency converter; the outer ring of the frequency converter is provided with a rotating speed ring and a voltage ring, the rotating speed ring and the voltage ring can be controlled to work in a switching mode by the outer ring of the frequency converter, the working mode of the outer ring of the frequency converter is a vector electric control mode when the rotating speed ring works, and the working mode of the outer ring of the frequency converter is a fully-switched vector braking control mode when the voltage ring works;

the control method of the magnetic suspension centrifuge comprises the following steps:

under the condition of normal operation after the magnetic suspension motor is started, controlling the working mode of the outer ring of the frequency converter to be the vector electric control mode; under the vector electric control mode, the rotating speed reference value of the rotating speed ring is set to be a set rotating speed value;

determining whether a magnetic bearing fault signal sent by the magnetic bearing controller is received; the magnetic bearing fault signal is a signal for generating a magnetic bearing impact fault of the magnetic suspension motor;

if a magnetic bearing fault signal sent by the magnetic bearing controller is received, controlling the working mode of the outer ring of the frequency converter to be switched from the vector electric control mode to the full-switch vector braking control mode; identifying the rotating speed of the magnetic suspension motor in the braking process of the magnetic suspension motor in the full-switch vector braking control mode to obtain a rotating speed identification value;

determining whether a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received after controlling the outer ring of the frequency converter to work in the full switching vector brake control mode; the magnetic bearing fault recovery signal is a recovery signal of a magnetic bearing impact fault of the magnetic suspension motor;

if a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received, controlling the working mode of the outer ring of the frequency converter to be switched from the full-switch vector braking control mode to the vector electric control mode; and under the vector electric control mode, gradually adjusting the rotating speed reference value of the rotating speed ring to the set rotating speed value on the basis of the rotating speed identification value so as to restart the magnetic suspension motor.

2. The control method of a magnetic levitation centrifuge as recited in claim 1, further comprising at least one of:

after determining whether a magnetic bearing fault signal sent by the magnetic bearing controller is received, if the magnetic bearing fault signal is not received, continuously controlling the outer ring of the frequency converter to work in the vector motor control mode;

and/or the presence of a gas in the atmosphere,

after determining whether a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received, if the magnetic bearing fault recovery signal sent by the magnetic bearing controller is not received, continuously controlling the working mode of the outer ring of the frequency converter to be the full-switching vector braking control mode; continuously identifying the rotating speed of the magnetic suspension motor in the braking process of the magnetic suspension motor in the full-switch vector braking control mode to obtain a rotating speed identification value;

3. The control method of a magnetic suspension centrifuge according to claim 1 or 2, characterized in that the outer ring of the frequency converter is further provided with a mode switching unit;

the mode switching unit can enable the working mode flag of the outer ring of the frequency converter to be a first setting flag in the vector electric control mode; and under the full-switching vector braking control mode, the working mode mark of the outer ring of the frequency converter is made to be a second set mark.

4. The control method of a magnetic levitation centrifuge as recited in any one of claims 1 to 3, wherein,

determining whether a magnetic bearing fault signal sent by the magnetic bearing controller is received, comprising:

determining whether the working mode flag of the outer ring of the frequency converter is changed from a first set flag to a second set flag;

if the working mode mark of the outer ring of the frequency converter is changed from a first set mark to a second set mark, determining that a magnetic bearing fault signal sent by the magnetic bearing controller is received;

if the working mode mark of the outer ring of the frequency converter is still the first set mark, determining that the magnetic bearing fault signal sent by the magnetic bearing controller is not received;

and/or the presence of a gas in the gas,

determining whether a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received, comprising:

determining whether the working mode flag of the outer ring of the frequency converter is changed from a second setting flag to a first setting flag;

if the working mode mark of the outer ring of the frequency converter is changed from the second setting mark to the first setting mark, determining that a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received;

and if the working mode mark of the outer ring of the frequency converter is still the second set mark, determining that the magnetic bearing fault recovery signal sent by the magnetic bearing controller is not received.

5. The control device of the magnetic suspension centrifugal machine is characterized in that the magnetic suspension centrifugal machine is provided with a magnetic suspension motor, a bearing controller and a frequency converter; the outer ring of the frequency converter is provided with a rotating speed ring and a voltage ring, the outer ring of the frequency converter can control the rotating speed ring and the voltage ring to work in a switching mode, the working mode of the outer ring of the frequency converter is a vector electric control mode when the rotating speed ring works, and the working mode of the outer ring of the frequency converter is a full-switch vector braking control mode when the voltage ring works;

the control device of the magnetic suspension centrifugal machine comprises:

the control unit is configured to control the working mode of the outer ring of the frequency converter to be the vector electric control mode under the condition of normal operation after the magnetic suspension motor is started; under the vector electric control mode, the rotating speed reference value of the rotating speed ring is set to be a set rotating speed value;

the control unit further configured to determine whether a magnetic bearing fault signal sent by the magnetic bearing controller is received; the magnetic bearing fault signal is a signal for generating a magnetic bearing impact fault of the magnetic suspension motor;

the control unit is further configured to control the working mode of the outer ring of the frequency converter to be switched from the vector motor control mode to the full-switching vector brake control mode if a magnetic bearing fault signal sent by the magnetic bearing controller is received; identifying the rotating speed of the magnetic suspension motor in the braking process of the magnetic suspension motor in the full-switch vector braking control mode to obtain a rotating speed identification value;

the control unit is further configured to determine whether a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received after controlling the outer loop of the frequency converter to operate in the full switching vector brake control mode; the magnetic bearing fault recovery signal is a recovery signal of a magnetic bearing impact fault of the magnetic suspension motor;

the control unit is further configured to control the working mode of the outer ring of the frequency converter to be switched from the full-switching vector braking control mode to the vector motor control mode if a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received; and under the vector electric control mode, gradually adjusting the rotating speed reference value of the rotating speed ring to the set rotating speed value on the basis of the rotating speed identification value so as to realize the restart of the magnetic suspension motor.

6. The control device of a magnetic levitation centrifuge as recited in claim 5, further comprising at least one of:

the control unit is further configured to, after determining whether a magnetic bearing fault signal sent by the magnetic bearing controller is received, if the magnetic bearing fault signal is not received, continue to control the outer ring of the frequency converter to operate in the vector motor control mode;

and/or the presence of a gas in the gas,

the control unit is further configured to, after determining whether a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received, if the magnetic bearing fault recovery signal sent by the magnetic bearing controller is not received, continue to control the working mode of the outer ring of the frequency converter to be the full-switching vector braking control mode; continuously identifying the rotating speed of the magnetic suspension motor in the braking process of the magnetic suspension motor in the full-switch vector braking control mode to obtain a rotating speed identification value;

7. The control device of a magnetic suspension centrifuge according to claim 5 or 6, characterized in that the outer ring of the frequency converter is further provided with a mode switching unit;

the mode switching unit can enable the working mode mark of the outer ring of the frequency converter to be a first set mark in the vector electric control mode; and under the full-switching vector braking control mode, the working mode mark of the outer ring of the frequency converter is made to be a second set mark.

8. Control device of a magnetic levitation centrifuge according to any one of claims 5 to 7, wherein,

the control unit determining whether a magnetic bearing fault signal transmitted by the magnetic bearing controller is received, including:

and/or the presence of a gas in the gas,

the control unit determining whether a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received, includes:

if the working mode flag of the outer ring of the frequency converter is changed from the second setting flag to the first setting flag, determining that a magnetic bearing fault recovery signal sent by the magnetic bearing controller is received;

9. A magnetic levitation centrifuge, comprising: control device of a magnetic levitation centrifuge as claimed in any of claims 5 to 8.

10. A storage medium, characterized in that the storage medium comprises a stored program, wherein the program, when executed, controls an apparatus in which the storage medium is located to perform the control method of a magnetic levitation centrifuge as claimed in any one of claims 1 to 4.