Fault-tolerant control method and system for magnetic suspension expansion generator controller

Abstract

The invention discloses a fault-tolerant control method and system for a magnetic suspension expansion generator controller, and belongs to the field of magnetic suspension bearing control. A magnetic suspension bearing in a generator has N degrees of freedom and comprises 2N windings A1-AN and B1-BN which are sequentially connected in series; the magnetic suspension bearing adopts a full-bridge series winding topological structure; the method comprises the steps that currents ian and icn in a winding An and a winding Bn are detected, n belongs to {1, 2,..., N}, if ian + icngt; if yes, judging that an upper switch tube of a bridge arm Ln and a lower switch tube of a bridge arm Ln + 1 connected with An and an upper switch tube of a bridge arm Ln + N and a lower switch tube of a bridge arm Ln + N connected with Bn have short-circuit faults; and calculating the current magnitude and the current direction of each winding by taking the resultant electromagnetic force generated by the winding on each degree of freedom as a preset value as a target, generating a PWM signal for controlling each switch tube in each bridge arm, and applying the PWM signal to the corresponding switch tube. According to the invention, short-circuit fault identification and fault tolerance can be realized for the magnetic suspension expansion generator controller based on the series winding topology.

Description

Technical Field

[0001] The present invention belongs to the field of magnetic suspension bearing control, and more specifically, relates to a fault-tolerant control method and system for a magnetic suspension expansion generator controller. Background Art

[0002] As a device that efficiently utilizes low-temperature waste heat to generate electricity, the magnetic levitation expansion generator has the advantages of low loss, high efficiency, and long life. In recent years, it has gradually been widely used in the industrial field.

[0003] As the core part of the magnetic levitation expansion generator, the magnetic bearing is a device that relies on electromagnetic force to suspend the rotor in the air, enabling the rotor to operate in a non-contact state, thereby achieving lubrication-free and friction-free working characteristics and extending the service life of the equipment. This type of bearing is an excellent choice to replace traditional mechanical bearings and is widely used in centrifugal compressors, high-speed flywheels, vacuum molecular pumps and other equipment that require the rotor to run at high speed or maintain a vacuum clean environment. The key components of the active magnetic bearing system include the rotor, sensor, controller and power amplifier. Among them, the power amplifier, as the core component of electromechanical conversion, plays an indispensable role in the control of the entire magnetic levitation expansion generator.

[0004] The power amplifier converts the current command into the actual current of the winding in order to accurately control the electromagnetic attraction of the magnetic bearing. When the switch element in the power amplifier circuit fails, the control function of the bridge arm voltage will fail, causing the winding current to deviate from the set value, further causing rotor instability, which may cause the rotor to fall, or even cause serious faults such as system shutdown. In this regard, in the patent document with application publication number CN112901658A, a fault-tolerant control system for a magnetic suspension bearing switch short circuit fault is disclosed, in which a new fault-tolerant topology is proposed. However, it can only solve the fault-tolerant problem when the switch device has a short circuit fault, and cannot cope with the short circuit fault of the switch device. When the switch element has a short circuit fault, the switch element continues to conduct, and the winding current rises sharply. This fault will bring more serious harm to the magnetic suspension bearing and even the entire magnetic suspension expansion motor.

[0005] In the patent document with application publication number CN116498651A, a switch short-circuit fault-tolerant control method and system for magnetic suspension bearings are disclosed, which proposes a method for identifying short-circuit faults of switch devices for a half-bridge topology structure, but cannot implement a corresponding fault-tolerant mechanism. In the patent document with application publication number CN116857280A, a switch short-circuit fault-tolerant topology circuit for a four-degree-of-freedom magnetic suspension bearing is disclosed, which proposes a method for identifying short-circuit faults of switch devices and a corresponding short-circuit fault-tolerant strategy for a reverse common bridge arm topology structure.

[0006] In the field of electromagnetic bearings, the series winding topology is a topology different from the full-bridge topology and the reverse common bridge arm topology. It can maximize the use of the power supply voltage, so that the output voltage amplitude reaches the full DC voltage, and matches the open winding full-bridge inverter. The motor speed range can exceed 70% of the conventional voltage source inverter (VSI) motor. The short-circuit fault tolerance strategy proposed for the reverse common bridge arm topology is not applicable to magnetic bearings based on the series winding topology. Summary of the invention

[0007] In view of the defects of the prior art and the need for improvement, the present invention provides a fault-tolerant control method and system for a magnetic levitation expansion generator controller, the purpose of which is to realize short-circuit fault identification and fault tolerance of a magnetic levitation expansion generator controller based on a series winding topology, and to improve the operating stability and safety of the magnetic levitation expansion generator.

[0008] To achieve the above object, according to one aspect of the present invention, a fault-tolerant control method for a magnetic levitation expansion generator controller is provided. The magnetic bearing in the magnetic levitation expansion generator has N degrees of freedom and includes 2N windings A1 to A2. N and B1~B N , Winding A n and winding B n Used to control the nth degree of freedom, n∈{1,2,……,N}; the magnetic bearing adopts a full-bridge series winding topology structure, including 2N+1 bridge arms L1~L 2N+1 ; 2N windings according to A1~A N 、B1~B N The order is connected in series, winding A n The two ends of the bridge arm L n and L n+1 The midpoint of winding B is connected n The two ends of the bridge arm L n+N and L n+N+1 The midpoint of is connected; the fault tolerance control method includes: short circuit fault identification and short circuit fault tolerance;

[0009] Short circuit fault identification includes: detection of winding A n and B n The current i an and i cn , if the sum of the two is greater than the preset current threshold i limiit ', then it is determined that the winding A used to control n and B n A set of switch tubes S 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 There is a short circuit fault; where S2n-1 is the bridge arm L n The upper switch tube, S 2n+2 is the bridge arm L n+1 The lower switch tube, S 2n+2N-1 is the bridge arm L n+N The upper switch tube, S 2n+2N+2 is the bridge arm L n+N+1 The lower switch tube;

[0010] Short-circuit fault tolerance includes: after identifying a short-circuit fault, calculating the current magnitude and current direction of each winding with the goal of making the combined electromagnetic force generated by the two windings on each degree of freedom a preset value; generating a PWM signal for controlling the on and off of each switch tube in each bridge arm according to the current magnitude and current direction of each winding, and applying it to the corresponding switch tube.

[0011] Further, after identifying the control winding A n and B n A set of switch tubes S 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 After a short circuit fault occurs, the current magnitude and current direction of each winding are calculated with the goal of making the resultant electromagnetic force generated by the two windings on each degree of freedom equal to a preset value, including the following steps:

[0012] S1: Positioning switch tube S 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 There is a short-circuit fault in the switch tube. If it is used to control winding A n If the switch tube is on, it will transfer to S2; otherwise, it will transfer to S3;

[0013] S2: Set winding A1~A n The current magnitude is equal to the original current magnitude, and the current direction is opposite to the original current direction, and the winding A is set n+1 ~A N The current magnitude is equal to the original current magnitude, and the current direction is the same as the original current direction. The resultant electromagnetic force generated by the two windings on each degree of freedom is taken as the preset value as the target. Calculate the windings B1~B N The magnitude and direction of the current;

[0014] S3: Set winding B1~B n The current magnitude of the winding B is equal to the original current magnitude and the current direction is opposite to the original current direction. n+1 ~B N The current magnitude is equal to the original current magnitude, and the current direction is the same as the original current direction. The resultant electromagnetic force generated by the two windings on each degree of freedom is taken as the preset value as the target. Calculate the windings A1~AN The magnitude and direction of the current;

[0015] The original current magnitude and original current direction of the winding respectively represent the current magnitude and current direction of the winding under normal working conditions.

[0016] Furthermore, in step S1, the switch tube S is positioned 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 The switch tubes with short circuit faults include:

[0017] Monitoring bridge arm L n , L n+1 , L n+N and L n+N+1 Voltage command value;

[0018] If the bridge arm L n The voltage command value decreases and eventually reaches negative saturation, then the switch tube S 2n-1 A short circuit fault occurs;

[0019] If the bridge arm L n+1 The voltage command value increases and eventually reaches positive saturation, then the switch tube S 2n+2 A short circuit fault occurs;

[0020] If the bridge arm L n+N The voltage command value decreases and eventually reaches negative saturation, then the switch tube S 2n+2N-1 A short circuit fault occurs;

[0021] If the bridge arm L n+N+1 The voltage command value increases and eventually reaches positive saturation, then the switch tube S 2n+2N+2 A short circuit fault has occurred.

[0022] Furthermore, in the nth degree of freedom, the calculation expression of the resultant electromagnetic force generated by the two windings is:

[0023]

[0024] Where F is the electromagnetic force generated by the two windings on the nth degree of freedom before the short circuit fault occurs; μ0 represents the vacuum magnetic permeability, m represents the number of turns of the winding, and A α represents the magnetic pole area, α represents the angle between the magnetic pole and the net force; dis0 represents twice the air gap of the magnetic bearing, and dis1 represents the distance from the rotor center to coil A. n The distance to the magnetic pole; I an and I cn Respectively represent winding A n and B n of current.

[0025] Furthermore, the fault-tolerant control method of the magnetic levitation expansion generator controller provided by the present invention further includes: circuit breaker fault identification; circuit breaker fault identification includes:

[0026] Detection winding A n and B n The current i an and i cn , if the sum of the two is less than the preset current threshold i limiit ″, then it is determined that the winding A used to control n and B n A set of switch tubes S 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 There is a circuit breaker fault;

[0027] Among them, i limiit ″ limiit ′.

[0028] Furthermore, the fault-tolerant control method of the magnetic levitation expansion generator controller provided by the present invention further includes: circuit breaker fault location; circuit breaker fault location includes:

[0029] After identifying the control winding A n and B n A set of switch tubes S 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 After a circuit breaker fault occurs, monitor the bridge arm L n , L n+1 , L n+N and L n+N+1 Voltage command value;

[0030] If the bridge arm L n The voltage command value increases and eventually reaches positive saturation, then the switch tube S 2n-1 A circuit breaker failure occurs;

[0031] If the bridge arm L n+1 The voltage command value decreases and eventually reaches negative saturation, then the switch tube S 2n+2 A short circuit fault occurs;

[0032] If the bridge arm L n+N The voltage command value increases and eventually reaches positive saturation, then the switch tube S 2n+2N-1 A circuit breaker failure occurs;

[0033] If the bridge arm L n+N+1 The voltage command value decreases and eventually reaches negative saturation, then the switch tube S 2n+2N+2 A circuit breaker failure occurred. ​

[0034] According to another aspect of the present invention, a fault-tolerant control system of a magnetic levitation expansion generator controller is provided. The magnetic bearing in the magnetic levitation expansion generator has N degrees of freedom and includes 2N windings A1-A2. N and B1~B N , Winding A n and winding B n Used to control the nth degree of freedom, n∈{1,2,……,N}; the magnetic bearing adopts a full-bridge series winding topology structure, including 2N+1 bridge arms L1~L 2N+1 ; 2N windings according to A1~A N 、B1~B N The order is connected in series, winding A n The two ends of the bridge arm L n and L n+1 The midpoint of winding B is connected n The two ends of the bridge arm L n+N and L n+N+1 The midpoints of are connected;

[0035] The fault-tolerant control system includes:

[0036] Short circuit fault identification module, used to detect winding A n and B n The current i an and i cn , and the sum of the two is greater than the preset current threshold i limiit ', it is determined that the winding A used to control n and B n A set of switch tubes S 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 There is a short circuit fault; where S 2n-1 is the bridge arm L n The upper switch tube, S 2n+2 is the bridge arm L n+1 The lower switch tube, S 2n+2N-1 is the bridge arm L n+N The upper switch tube, S 2n+2N+2 is the bridge arm L n+N+1 The lower switch tube;

[0037] And a short-circuit fault tolerance module is used to calculate the current size and current direction of each winding after identifying a short-circuit fault, with the goal of making the combined electromagnetic force generated by the two windings in each degree of freedom a preset value; according to the current size and current direction of each winding, a PWM signal for controlling the conduction and shutdown of each switch tube in each bridge arm is generated and applied to the corresponding switch tube.

[0038] Furthermore, the short-circuit fault tolerance module identifies the control winding A n and B n A set of switch tubes S 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 After a short circuit fault occurs, the current magnitude and current direction of each winding are calculated with the goal of making the resultant electromagnetic force generated by the two windings on each degree of freedom equal to a preset value, including the following steps:

[0039] S1: Positioning switch tube S 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 There is a short-circuit fault in the switch tube. If it is used to control winding A n If the switch tube is on, it will transfer to S2; otherwise, it will transfer to S3;

[0040] S2: Set winding A1~A n The current magnitude is equal to the original current magnitude, and the current direction is opposite to the original current direction, and the winding A is set n+1 ~A N The current magnitude is equal to the original current magnitude, and the current direction is the same as the original current direction. The resultant electromagnetic force generated by the two windings on each degree of freedom is taken as the preset value as the target. Calculate the windings B1~B N The magnitude and direction of the current;

[0041] S3: Set winding B1~B n The current magnitude of the winding B is equal to the original current magnitude and the current direction is opposite to the original current direction. n+1 ~B N The current magnitude is equal to the original current magnitude, and the current direction is the same as the original current direction. The resultant electromagnetic force generated by the two windings on each degree of freedom is taken as the preset value as the target. Calculate the windings A1~A N The magnitude and direction of the current;

[0042] The original current magnitude and original current direction of the winding respectively represent the current magnitude and current direction of the winding under normal working conditions.

[0043] Furthermore, in step S1, the switch tube S is positioned 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 The switch tubes with short circuit faults include:

[0044] Monitoring bridge arm L n , L n+1 , L n+N and L n+N+1 Voltage command value;

[0045] If the bridge arm L n The voltage command value decreases and eventually reaches negative saturation, then the switch tube S 2n-1 A short circuit fault occurs;

[0046] If the bridge arm L n+1 The voltage command value increases and eventually reaches positive saturation, then the switch tube S 2n+2 A short circuit fault occurs;

[0047] If the bridge arm L n+N The voltage command value decreases and eventually reaches negative saturation, then the switch tube S 2n+2N-1 A short circuit fault occurs;

[0048] If the bridge arm L n+N+1 The voltage command value increases and eventually reaches positive saturation, then the switch tube S 2n+2N+2 A short circuit fault has occurred.

[0049] Furthermore, the magnetic levitation expansion generator controller fault-tolerant control system provided by the present invention further includes:

[0050] Open circuit fault identification module, used to detect winding A n and B n The current i an and i cn , and the sum of the two is less than the preset current threshold i limiit ″, it is determined that the winding A is used to control n and B n A set of switch tubes S 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 There is a circuit breaker fault;

[0051] Among them, i limiit ″ limiit ′.

[0052] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

[0053] (1) Based on the working characteristics of the magnetic bearing with a full-bridge series winding topology, the present invention proposes a corresponding short-circuit fault identification method and a short-circuit fault tolerance strategy, which can effectively identify the short-circuit fault of the switch tube and perform fault tolerance in a timely manner, effectively improving the operating safety and stability of the magnetic bearing and the entire magnetic expansion motor.

[0054] (2) The present invention further proposes a method for identifying a circuit breaker fault and a corresponding method for locating a faulty switch tube, thereby further improving the operating safety and stability of the magnetic bearing and the entire magnetic expansion motor.​ BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 It is a topological diagram of a five-degree-of-freedom magnetic bearing based on a full-bridge series winding topology;

[0056] Figure 2 for Figure 1 Schematic diagram of the symbols of each bridge arm, switch tube and bridge arm;

[0057] Figure 3 for Figure 2 , a schematic diagram of winding A1 and the bridge arm connected thereto in normal working mode;

[0058] Figure 4 for Figure 2 , a schematic diagram of the current change of the winding A1 when the switch tube S1 used to control the winding A1 has a short circuit fault;

[0059] Figure 5 for Figure 2 Control block diagram of the topology shown;

[0060] Figure 6 A flow chart of a fault-tolerant control method for a magnetic levitation expansion generator controller provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0062] In the present invention, the terms "first", "second", etc. (if any) in the present invention and the drawings are used to distinguish similar objects but not necessarily to describe a specific order or sequence.

[0063] The magnetic bearing system is the core part of the magnetic levitation expansion generator. Accurately detecting the short-circuit fault of the switch device in its power amplifier and performing corresponding fault tolerance processing are crucial for the control and safe operation of the entire magnetic levitation expansion generator. Before explaining the technical solution of the present invention in detail, the magnetic bearing topology involved in the present invention is briefly introduced.

[0064] The magnetic bearing has multiple degrees of freedom, with N representing the number of its degrees of freedom. Accordingly, the magnetic bearing has 2N windings, two in a group, to achieve control of one degree of freedom. When a full-bridge series winding topology is adopted, the 2N windings are connected in series in sequence, and each winding is connected to the midpoint of the two bridge arms of an H-bridge. Adjacent windings share one bridge arm. Therefore, there are a total of 2N+1 bridge arms (2N-1 common bridge arms and 2 non-common bridge arms). The upper and lower tubes in each bridge arm are switching devices, and the upper and lower ends of each bridge arm are respectively connected to the positive and negative poles of the DC power supply. In practical applications, a more typical one is a 5-degree-of-freedom magnetic bearing, whose 5 degrees of freedom specifically refer to 4 degrees of freedom in the radial direction and 1 degree of freedom in the axial direction. Accordingly, the topological structure includes 10 windings, 9 common bridge arms and 2 non-common bridge arms, such as Figure 1 shown.

[0065] A1~A N 、B1~B N Represents 2N windings, where A n and B n Represents a pair of windings used to control the nth degree of freedom, n∈{1,2,……,N}; L1~L 2N+1 Represents 2N+1 bridge arms, then winding A n The bridge arm connected is L n and L n+1 , Winding B n The bridge arm connected is L n+N and L n+N+1 , with S 2x-1 and S 2x Respectively represent the bridge arm L x The upper switch and the lower switch of x∈{1,2,……,2N+1} are used to control winding A. n The switch tube is S 2n-1 and S 2n+2 , i.e. bridge arm L n The upper switch tube and bridge arm L n+1 The lower switch tube is used to control winding B n The switch tube is S 2n+2N-1 and S 2n+2N+2 , i.e. bridge arm L n+N The upper switch tube and bridge arm L n+N+1 The lower switch tube. Referring to this symbolic representation, Figure 1 In the diagram, the symbols of each winding, bridge arm, and switch tube are as follows: Figure 2 shown.

[0066] For any winding, by controlling the on / off state of the switch tube controlling the winding, the corresponding winding current can be in different states. nFor example, the state of the winding current is as follows:

[0067] When the switch S 2n-1 and S 2n+2 When both are turned on (11 mode), the winding voltage is equal to the DC voltage source voltage V dc , the winding current increases, and it is in charging mode;

[0068] When the switch S 2n-1 and S 2n+2 When one is turned on and the other is turned off (10 mode or 01 mode), the winding voltage is close to 0, and it is in freewheeling mode;

[0069] When the switching device S 2n-1 and S 2n+2 When both are turned off (00 mode), the winding voltage is equal to -V dc , the winding current increases and is in discharge mode.

[0070] In normal working mode, when the current directions of adjacent windings are consistent, the bias currents of the windings cancel each other out, the current stress on the common bridge arm is small, the conduction loss and switching loss during switching are reduced, and when the current of each winding is normally controlled, the sum of the currents of the two windings on the same degree of freedom is equal to twice the bias current;

[0071] i an +i cn =2i0

[0072] Among them, i an and i cn Respectively represent winding A n and B n The current i0 represents the bias current.

[0073] In normal working mode, the current direction of all windings is consistent. Optionally, the current in each winding is set to be from left to right. By controlling the driving signal of the switch device in each bridge arm, the midpoint voltage of each bridge arm is adjusted, and then the current of each winding can be controlled. The pulse width modulation (PWM) control method is adopted to make the duty cycle signals of the upper and lower switches of each bridge arm complementary. To prevent the bridge arm from being directly turned on, the upper and lower switches of each bridge arm cannot be turned on at the same time; according to the reference current signal, the reference differential current and bias current are obtained through the PI controller, and then the voltage difference of adjacent bridge arms and the reference voltage of each bridge arm are obtained to adjust the duty cycle of the corresponding bridge arm.

[0074] by Figure 2 Taking the winding A1 in the example, in the normal working mode, the switch state of the control winding A1 and the current in the winding A1 are as follows: Figure 3 When a short circuit occurs, the winding with the faulty switch cannot continue to control the dynamic current, as shown in Figure 4As shown. Due to the short-circuit fault, the mode in which both S1 and S4 are turned off is blocked (00 mode), and only the charging mode and the freewheeling mode exist, but the discharging mode does not exist, so that the winding current i1 increases and cannot maintain the original constant current value.

[0075] Based on this, the present invention proposes a basis for identifying switch short-circuit faults in magnetic bearings based on series winding topology, namely: detecting the sum of the winding currents of the two windings corresponding to each degree of freedom to obtain the winding bias current. If the winding bias current increases and the sum of the currents of the two windings is greater than the threshold value i limiit ′, it means that one of the four switching devices used to control the two windings corresponding to this degree of freedom has a short circuit fault.

[0076] In order to ensure the safe and stable operation of the magnetic bearing and even the entire magnetic expansion generator when a short circuit fault occurs, the present invention further proposes a corresponding short circuit fault tolerance mechanism in combination with the working mode of the winding series topology. The specific analysis is as follows:

[0077] In normal working mode, the current of each winding is determined by the voltage difference of the bridge arm to which it is connected and the winding impedance. Z represents the impedance of each winding, U x Indicates bridge arm L x The output voltage of winding A n For example, the current i an It can be expressed as:

[0078]

[0079] During the suspension process of the magnetic bearing, the common mode current remains unchanged, and the bridge arm voltages U1 and U 2N+1 are equal, then accordingly, the two non-common bridge arms L1 and L 2N+1 The duty cycle of the switching devices in the circuit needs to be kept consistent, so the independent bridge arm voltage variables are only U1~U 2N .

[0080] by Figure 1 For example, if the bias currents of each winding are equal, the sum of the two winding currents corresponding to the five degrees of freedom can be set to the same value:

[0081] I a1 +I c1 =I a2 +I c2 =…=I a5 +I c5

[0082] At the same time, the relationship between the winding current and the bridge arm voltage can be expressed as follows:

[0083]

[0084] In normal working mode, based on the above relationship between winding current and bridge arm voltage, the average value of all independent bridge arm voltages can be U dc / 2, based on the above change matrix, the command value of each bridge arm voltage is obtained, and then the corresponding switch device duty cycle is adjusted according to the bridge arm voltage command value, so that the current of each winding can be controlled. The corresponding control block diagram is as follows Figure 5 shown.

[0085] Compared with the half-bridge topology, the full-bridge winding series topology has more switching devices, the current direction of each winding can be changed independently, and it has more topological operating modes, and some operating modes can be used as fault-tolerant working modes. Based on this, in the short-circuit fault tolerance mechanism proposed in the present invention, considering that the winding with a faulty switching device cannot continue to control the dynamic current and can only keep the current constant, the current in the opposite winding is controlled by a PID controller, a power amplifier, and a PI controller, so that the resultant electromagnetic force on the rotor is the same as before the fault occurs, so that the rotor in the magnetic bearing can still be suspended in this fault state, avoiding control failure and rotor falling due to a short-circuit fault of the switching device.

[0086] Specifically, if the winding with the faulty switching device is A n , then the winding with the faulty switching device and the windings A1 to A1 before it n The current magnitude remains constant, and the direction of the current is opposite to the original state (the state in the normal working mode). n+1 ~A N The current in the circuit remains constant and its direction remains the same as the original state. N As windings A1~A N The opposite winding of the faulty switch is the opposite winding of the faulty switch. n , then the winding with the faulty switching device and the windings B1 to B1 before it n The current magnitude remains constant, and the direction of the current is opposite to the original state (the state in the normal working mode). n+1 ~B N The current magnitude in the circuit remains constant, and the current direction remains the same as the original state. N As windings B1~B N The opposite winding of the inverter bears the entire dynamic change.

[0087] After determining the magnitude and direction of the current in each winding, a drive signal for controlling the switch devices in each bridge arm can be generated to adjust the midpoint voltage of each bridge arm to achieve control of the winding current.

[0088] The function of the power amplifier and the winding is to generate electromagnetic force. When performing single-axis control, the two coils with current generate a pair of forces in opposite directions to suspend the rotor. At this time, the relationship between the resultant force generated by a pair of electromagnetic forces in opposite directions and the differential current and bias current on the corresponding winding is:

[0089]

[0090] Where F is the electromagnetic force generated by the two windings on the nth degree of freedom before the short circuit fault occurs; μ0 represents the vacuum magnetic permeability, m represents the number of turns of the winding, and A α represents the magnetic pole area, α represents the angle between the magnetic pole and the net force; dis1 represents the distance from the rotor center to coil A n Corresponding to the distance of the magnetic pole, dis2 represents the distance from the rotor center to coil B n The distance to the magnetic pole; I an and I cn They represent the winding A calculated according to the above fault tolerance mechanism. n and B n of current.

[0091] The above calculation expression can be further expressed as follows:

[0092]

[0093] Where dis0 represents twice the air gap of the magnetic bearing.

[0094] There are various ways to distribute the currents of the two windings. The performance of the rotor will not change as long as the currents of the two windings satisfy the following formula, which can be used to calculate the reference current of the opposite winding:

[0095]

[0096] Among them, i bias represents the input bias current, i ref represents the differential current, i a|ref Indicates winding A under normal working condition n The bias current, i c|ref Indicates winding B under normal working condition n of bias current.

[0097] The following are examples.

[0098] Embodiment 1:

[0099] A fault-tolerant control method for a magnetic levitation expansion generator controller.

[0100] In this embodiment, the magnetic bearing in the magnetic suspension expansion generator has N degrees of freedom and includes 2N windings A1 to A2. Nand B1~B N , Winding A n and winding B n Used to control the nth degree of freedom, n∈{1,2,……,N}; the magnetic bearing adopts a full-bridge series winding topology structure, including 2N+1 bridge arms L1~L 2N+1 ; 2N windings according to A1~A N 、B1~B N The order is connected in series, winding A n The two ends of the bridge arm L n and L n+1 The midpoint of winding B is connected n The two ends of the bridge arm L n+N and L n+N+1 The midpoints are connected.

[0101] like Figure 6 The fault tolerance control method of the magnetic levitation expansion generator controller provided in this embodiment includes: short circuit fault identification and short circuit fault tolerance;

[0102] Short circuit fault identification includes: detection of winding A n and B n The current i an and i cn , if the sum of the two is greater than the preset current threshold i limiit ', then it is determined that the winding A used to control n and B n A set of switch tubes S 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 There is a short circuit fault; where S 2n-1 is the bridge arm L n The upper switch tube, S 2n+2 is the bridge arm L n+1 The lower switch tube, S 2n+2N-1 is the bridge arm L n+N The upper switch tube, S 2n+2N+2 is the bridge arm L n+N+1 The lower switch tube;

[0103] Short-circuit fault tolerance includes: after identifying a short-circuit fault, calculating the current magnitude and current direction of each winding with the goal of making the combined electromagnetic force generated by the two windings on each degree of freedom a preset value; generating a PWM signal for controlling the on and off of each switch tube in each bridge arm according to the current magnitude and current direction of each winding, and applying it to the corresponding switch tube.

[0104] In this embodiment, the control winding A is identified. n and B n A set of switch tubes S 2n-1, S 2n+2 , S 2n+2N-1 and S 2n+2N+2 After a short circuit fault occurs, the current magnitude and current direction of each winding are calculated with the goal of making the combined electromagnetic force generated by the two windings on each degree of freedom equal to a preset value, which specifically includes the following steps:

[0105] S1: Positioning switch tube S 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 There is a short-circuit fault in the switch tube. If it is used to control winding A n If the switch tube is on, it will transfer to S2; otherwise, it will transfer to S3;

[0106] S2: Set winding A1~A n The current magnitude is equal to the original current magnitude, and the current direction is opposite to the original current direction, and the winding A is set n+1 ~A N The current magnitude is equal to the original current magnitude, and the current direction is the same as the original current direction. The resultant electromagnetic force generated by the two windings on each degree of freedom is taken as the preset value as the target. Calculate the windings B1~B N The magnitude and direction of the current;

[0107] S3: Set winding B1~B n The current magnitude of the winding B is equal to the original current magnitude and the current direction is opposite to the original current direction. n+1 ~B N The current magnitude is equal to the original current magnitude, and the current direction is the same as the original current direction. The resultant electromagnetic force generated by the two windings on each degree of freedom is taken as the preset value as the target. Calculate the windings A1~A N The magnitude and direction of the current;

[0108] The original current magnitude and original current direction of the winding respectively represent the current magnitude and current direction of the winding under normal working conditions.

[0109] After determining the group of switch devices with short-circuit faults, the specific faulty switch can be located according to the bridge arm voltage command. When the switch device of the upper bridge arm is short-circuited, since the bridge arm voltage is always higher than the command value, under the action of the current loop PI controller, the command value of the bridge arm voltage will decrease and quickly reach negative saturation; similarly, when the switch device of the lower bridge arm is short-circuited, the corresponding bridge arm voltage command value will increase and quickly reach positive saturation. Based on this, in step S1 of this embodiment, the switch tube S is located. 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 The switch tubes with short circuit faults include:

[0110] Monitoring bridge arm Ln , L n+1 , L n+N and L n+N+1 Voltage command value;

[0111] If the bridge arm L n The voltage command value decreases and eventually reaches negative saturation, then the switch tube S 2n-1 A short circuit fault occurs;

[0112] If the bridge arm L n+1 The voltage command value increases and eventually reaches positive saturation, then the switch tube S 2n+2 A short circuit fault occurs;

[0113] If the bridge arm L n+N The voltage command value decreases and eventually reaches negative saturation, then the switch tube S 2n+2N-1 A short circuit fault occurs;

[0114] If the bridge arm L n+N+1 The voltage command value increases and eventually reaches positive saturation, then the switch tube S 2n+2N+2 A short circuit fault has occurred.

[0115] If the switch tube S 2n-1 or S 2n+2 If a short circuit occurs, winding A n is a winding with a faulty switch tube. If the switch tube S 2n+2N-1 or S 2n+2N+2 If a short circuit occurs, winding B n It is the winding with a faulty switching tube.

[0116] The identification result of the short-circuit fault switch tube provides a reliable basis for the subsequent replacement or repair of the faulty switch device.

[0117] In the nth degree of freedom, the calculation expression of the resultant electromagnetic force generated by the two windings is:

[0118]

[0119] Where F is the electromagnetic force generated by the two windings on the nth degree of freedom before the short circuit fault occurs; μ0 represents the vacuum permeability, m represents the number of turns of the winding, and a α represents the magnetic pole area, α represents the angle between the magnetic pole and the net force; dis0 represents twice the air gap of the magnetic bearing, and dis1 represents the distance from the rotor center to coil A. n Corresponding distance to magnetic pole; I an and I cn Respectively represent winding A n and B n of current.

[0120] When calculating the current in the opposite winding, it can be calculated based on the above electromagnetic reasonable expression.

[0121] like Figure 6 As shown, this embodiment further includes: circuit breaker fault identification; circuit breaker fault identification includes:

[0122] Detection winding A n and B n The current i an and i cn , if the sum of the two is less than the preset current threshold i limiit ″, then it is determined that the winding A used to control n and B n A set of switch tubes S 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 There is a circuit breaker fault;

[0123] Among them, i limiit ″ limiit ′; It is easy to understand that i limiit ″ is less than twice the bias current, i limiit ’ is greater than twice the bias current.

[0124] like Figure 6 As shown, after determining the group of switch devices with open circuit fault, this embodiment can locate the specific faulty switch tube according to the bridge arm voltage command. When the switch device of the upper bridge arm is open circuit, since the bridge arm voltage is always lower than the command value, under the action of the current loop PI controller, the command value of the bridge arm voltage will increase and quickly reach positive saturation; similarly, when the switch device of the lower bridge arm is open circuit, the corresponding bridge arm voltage command value will decrease and quickly reach negative saturation. Based on this, this embodiment further includes open circuit fault location on the basis of short circuit fault identification; open circuit fault location includes:

[0125] After identifying the control winding A n and B n A set of switch tubes S 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 After a circuit breaker fault occurs, monitor the bridge arm L n , L n+1 , L n+N and L n+N+1 Voltage command value;

[0126] If the bridge arm L n The voltage command value increases and eventually reaches positive saturation, then the switch tube S 2n-1 A circuit breaker failure occurs;

[0127] If the bridge arm L​n+1 The voltage command value decreases and eventually reaches negative saturation, then the switch tube S 2n+2 A short circuit fault occurs;

[0128] If the bridge arm L n+N The voltage command value increases and eventually reaches positive saturation, then the switch tube S 2n+2N-1 A circuit breaker failure occurs;

[0129] If the bridge arm L n+N+1 The voltage command value decreases and eventually reaches negative saturation, then the switch tube S 2n+2N+2 A circuit breaker failure occurred.

[0130] The identification result of the circuit-breaking fault switch tube provides a reliable basis for the subsequent replacement or repair of the faulty switch device.

[0131] In general, this embodiment, based on the working characteristics of the magnetic bearing with full-bridge series winding topology, proposes a corresponding short-circuit fault identification method and short-circuit fault fault tolerance strategy, which can effectively identify the short-circuit fault of the switch tube and perform fault tolerance in time, effectively improving the operation safety and stability of the magnetic bearing and the entire magnetic expansion motor. On this basis, the present invention further proposes a short-circuit fault identification method of the switch tube and a corresponding faulty switch tube positioning method, further improving the operation safety and stability of the magnetic bearing and the entire magnetic expansion motor.

[0132] Embodiment 2:

[0133] A fault-tolerant control system for a magnetic levitation expansion generator controller.

[0134] In this embodiment, the magnetic bearing in the magnetic suspension expansion generator has N degrees of freedom and includes 2N windings A1 to A2. N and B1~B N , Winding A n and winding B n Used to control the nth degree of freedom, n∈{1,2,……,N}; the magnetic bearing adopts a full-bridge series winding topology structure, including 2N+1 bridge arms L1~L 2N+1 ; 2N windings according to A1~A N 、B1~B N The order is connected in series, winding A n The two ends of the bridge arm L n and L n+1 The midpoint of winding B is connected n The two ends of the bridge arm L n+N and L n+N+1 The midpoints are connected.

[0135] The fault-tolerant control system of the magnetic levitation expansion generator controller provided in this embodiment includes: a short-circuit fault identification module, a short-circuit fault tolerance module, a circuit-breaking fault identification module and a circuit-breaking fault location module. Among them:

[0136] Short circuit fault identification module, used to detect winding A n and B n The current i an and i cn , and the sum of the two is greater than the preset current threshold i limiit ', it is determined that the winding A used to control n and B n A set of switch tubes S 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 There is a short circuit fault; where S 2n-1 is the bridge arm L n The upper switch tube, S 2n+2 is the bridge arm L n+1 The lower switch tube, S 2n+2N-1 is the bridge arm L n+N The upper switch tube, S 2n+2N+2 is the bridge arm L n+N+1 The lower switch tube;

[0137] A short-circuit fault tolerance module is used to calculate the current magnitude and current direction of each winding after identifying a short-circuit fault, with the goal of making the electromagnetic force generated by the two windings on each degree of freedom a preset value; according to the current magnitude and current direction of each winding, generate a PWM signal for controlling the on and off of each switch tube in each bridge arm, and apply it to the corresponding switch tube;

[0138] Open circuit fault identification module, used to detect winding A n and B n The current i an and i cn , and the sum of the two is less than the preset current threshold i limiit ″, it is determined that the winding A is used to control n and B n A set of switch tubes S 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 There is a circuit breaker fault; i limiit ″ limiit ′;

[0139] The circuit breaker fault location module is used to identify the fault location of the control winding A. n and B n A set of switch tubes S 2n-1 , S 2n+2 , S​2n+2N-1 and S 2n+2N+2 When a circuit breaker fault occurs, do the following:

[0140] Monitoring bridge arm L n , L n+1 , L n+N and L n+N+1 Voltage command value;

[0141] If the bridge arm L n The voltage command value increases and eventually reaches positive saturation, then the switch tube S 2n-1 A circuit breaker failure occurs;

[0142] If the bridge arm L n+1 The voltage command value decreases and eventually reaches negative saturation, then the switch tube S 2n+2 A short circuit fault occurs;

[0143] If the bridge arm L n+N The voltage command value increases and eventually reaches positive saturation, then the switch tube S 2n+2N-1 A circuit breaker failure occurs;

[0144] If the bridge arm L n+N+1 The voltage command value decreases and eventually reaches negative saturation, then the switch tube S 2n+2N+2 A circuit breaker failure occurred.

[0145] In this embodiment, the short-circuit fault tolerance module identifies the control winding A. n and B n A set of switch tubes S 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 After a short circuit fault occurs, the current magnitude and current direction of each winding are calculated with the goal of making the resultant electromagnetic force generated by the two windings on each degree of freedom equal to a preset value, including the following steps:

[0146] S1: Positioning switch tube S 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 There is a short-circuit fault in the switch tube. If it is used to control winding A n If the switch tube is on, it will transfer to S2; otherwise, it will transfer to S3;

[0147] S2: Set winding A1~A n The current magnitude is equal to the original current magnitude, and the current direction is opposite to the original current direction, and the winding A is set n+1 ~A NThe current magnitude is equal to the original current magnitude, and the current direction is the same as the original current direction. The resultant electromagnetic force generated by the two windings on each degree of freedom is taken as the preset value as the target. Calculate the windings B1~B N The magnitude and direction of the current;

[0148] S3: Set winding B1~B n The current magnitude of the winding B is equal to the original current magnitude and the current direction is opposite to the original current direction. n+1 ~B N The current magnitude is equal to the original current magnitude, and the current direction is the same as the original current direction. The resultant electromagnetic force generated by the two windings on each degree of freedom is taken as the preset value as the target. Calculate the windings A1~A N The magnitude and direction of the current;

[0149] The original current magnitude and original current direction of the winding respectively represent the current magnitude and current direction of the winding under normal working conditions.

[0150] In this embodiment, in step S1 executed by the short-circuit fault tolerance module, the positioning switch tube S 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 The switch tubes with short circuit faults include:

[0151] Monitoring bridge arm L n , L n+1 , L n+N and L n+N+1 Voltage command value;

[0152] If the bridge arm L n The voltage command value decreases and eventually reaches negative saturation, then the switch tube S 2n-1 A short circuit fault occurs;

[0153] If the bridge arm L n+1 The voltage command value increases and eventually reaches positive saturation, then the switch tube S 2n+2 A short circuit fault occurs;

[0154] If the bridge arm L n+N The voltage command value decreases and eventually reaches negative saturation, then the switch tube S 2n+2N-1 A short circuit fault occurs;

[0155] If the bridge arm L n+N+1 The voltage command value increases and eventually reaches positive saturation, then the switch tube S 2n+2N+2 A short circuit fault has occurred.

[0156] In this embodiment, the specific implementation of each module can refer to the description in the above embodiment 1 and will not be repeated here.

[0157] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A fault-tolerant control method for a magnetic levitation expansion generator controller, wherein the magnetic bearing in the magnetic levitation expansion generator has N degrees of freedom and includes 2N windings A1 to A2. N and B1~B N , Winding A n and winding B n It is used to control the nth degree of freedom, n∈{1,2,……,n}; the magnetic bearing adopts a full-bridge series winding topology structure, including 2N+1 bridge arms L1~L 2N+1 ; 2N windings according to A1~A N 、B1~B N The order is connected in series, winding A n The two ends of the bridge arm L n and L n+1 The midpoint of winding B is connected n The two ends of the bridge arm L n+N and L n+N+1 The midpoints of are connected; it is characterized by that The fault tolerance control method comprises: short circuit fault identification and short circuit fault tolerance; The short circuit fault identification includes: detecting winding A n and B n The current i an and i cn , if the sum of the two is greater than the preset current threshold i limiit ′ , then it is determined that the winding A used to control n and B n A set of switch tubes S 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 There is a short circuit fault; where S 2n-1 is the bridge arm L n The upper switch tube, S 2n+2 is the bridge arm L n+1 The lower switch tube, S 2n+2N-1 is the bridge arm L n+N The upper switch tube, S 2n+2N+2 is the bridge arm L n+N+1 The lower switch tube; The short-circuit fault tolerance includes: after identifying a short-circuit fault, calculating the current magnitude and current direction of each winding with the goal of making the combined electromagnetic force generated by the two windings on each degree of freedom a preset value; generating a PWM signal for controlling the on and off of each switch tube in each bridge arm according to the current magnitude and current direction of each winding, and applying it to the corresponding switch tube.

2. The fault-tolerant control method for a magnetic levitation expansion generator controller according to claim 1, characterized in that: After identifying the control winding A n and B n A set of switch tubes S 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 After a short circuit fault occurs, the current magnitude and current direction of each winding are calculated with the goal of making the resultant electromagnetic force generated by the two windings on each degree of freedom equal to a preset value, including the following steps: S1: Positioning switch tube S 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 There is a short-circuit fault in the switch tube. If it is used to control winding A n If the switch tube is on, it will transfer to S2; otherwise, it will transfer to S3; S2: Set winding A1~A n The current magnitude is equal to the original current magnitude, and the current direction is opposite to the original current direction, and the winding A is set n+1 ~A N The current magnitude is equal to the original current magnitude, and the current direction is the same as the original current direction. The resultant electromagnetic force generated by the two windings on each degree of freedom is taken as the preset value as the target. Calculate the windings B1~B N The magnitude and direction of the current; S3: Set winding B1~B n The current magnitude of the winding B is equal to the original current magnitude and the current direction is opposite to the original current direction. n+1 ~B N The current magnitude is equal to the original current magnitude, and the current direction is the same as the original current direction. The resultant electromagnetic force generated by the two windings on each degree of freedom is taken as the preset value as the target. Calculate the windings A1~A N The magnitude and direction of the current; The original current magnitude and original current direction of the winding respectively represent the current magnitude and current direction of the winding under normal working conditions.

3. The fault-tolerant control method for a magnetic levitation expansion generator controller according to claim 2, characterized in that: In step S1, the switch tube S is positioned. 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 The switch tubes with short circuit faults include: Monitoring bridge arm L n , L n+1 , L n+N and L n+N+1 Voltage command value; If the bridge arm L n The voltage command value decreases and eventually reaches negative saturation, then the switch tube S 2n-1 A short circuit fault occurs; If the bridge arm L n+1 The voltage command value increases and eventually reaches positive saturation, then the switch tube S 2n+2 A short circuit fault occurs; If the bridge arm L n+N The voltage command value decreases and eventually reaches negative saturation, then the switch tube S 2n+2N-1 A short circuit fault occurs; If the bridge arm L n+N+1 The voltage command value increases and eventually reaches positive saturation, then the switch tube S 2n+2N+2 A short circuit fault has occurred.

4. The fault-tolerant control method for a magnetic levitation expansion generator controller according to any one of claims 1 to 3, characterized in that: In the nth degree of freedom, the calculation expression of the resultant electromagnetic force generated by the two windings is: Where F is the electromagnetic force generated by the two windings on the nth degree of freedom before the short circuit fault occurs; μ0 represents the vacuum magnetic permeability, m represents the number of turns of the winding, and A α represents the magnetic pole area, α represents the angle between the magnetic pole and the net force; dis0 represents twice the air gap of the magnetic bearing, and dis1 represents the distance from the rotor center to the coil A. n Corresponding distance to magnetic pole; I an and I cn Respectively represent winding A n and B n of current.

5. The fault-tolerant control method for a magnetic levitation expansion generator controller according to any one of claims 1 to 3, characterized in that: Also includes: Circuit breaker fault identification; The circuit breaker fault identification includes: Detection winding A n and B n The current i an and i cn , if the sum of the two is less than the preset current threshold i limiit ″, then it is determined that the winding A used to control n and B n A set of switch tubes S 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 There is a circuit breaker fault; Among them, i limiit ″ limiit ′.​ 6. The fault-tolerant control method for a magnetic levitation expansion generator controller according to claim 5, characterized in that: Also includes: Circuit breaker fault location; The circuit breaker fault location includes: After identifying the control winding A n and B n A set of switch tubes S 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 After a circuit breaker fault occurs, monitor the bridge arm L n , L n+1 , L n+N and L n+N+1 Voltage command value; If the bridge arm L n The voltage command value increases and eventually reaches positive saturation, then the switch tube S 2n-1 A circuit breaker failure occurs; If the bridge arm L n+1 The voltage command value decreases and eventually reaches negative saturation, then the switch tube S 2n+2 A short circuit fault occurs; If the bridge arm L n+N The voltage command value increases and eventually reaches positive saturation, then the switch tube S 2n+2N-1 A circuit breaker failure occurs; If the bridge arm L n+N+1 The voltage command value decreases and eventually reaches negative saturation, then the switch tube S 2n+2N+2 A circuit breaker failure occurred.

7. A fault-tolerant control system for a magnetic levitation expansion generator controller, wherein the magnetic bearing in the magnetic levitation expansion generator has N degrees of freedom and includes 2N windings A1 to A2. N and B1~B N , Winding A n and winding B n It is used to control the nth degree of freedom, n∈{1,2,……,N}; the magnetic bearing adopts a full-bridge series winding topology structure, including 2N+1 bridge arms L1~L 2N+1 ; 2N windings according to A1~A N 、B1~B N The order is connected in series, winding A n The two ends of the bridge arm L n and L n+1 The midpoint of winding B is connected n The two ends of the bridge arm L n+N and L n+N+1 The midpoints of are connected; It is characterized in that The fault-tolerant control system comprises: Short circuit fault identification module, used to detect winding A n and B n The current i an and i cn , and the sum of the two is greater than the preset current threshold i limiit ′ When the control winding A is used n and B n A set of switch tubes S 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 There is a short circuit fault; where S 2n-1 is the bridge arm L n The upper switch tube, S 2n+2 is the bridge arm L n+1 The lower switch tube, S 2n+2N-1 is the bridge arm L n+N The upper switch tube, S 2n+2N+2 is the bridge arm L n+N+1 The lower switch tube; And a short-circuit fault tolerance module is used to calculate the current size and current direction of each winding after identifying a short-circuit fault, with the goal of making the combined electromagnetic force generated by the two windings in each degree of freedom a preset value; according to the current size and current direction of each winding, a PWM signal for controlling the conduction and shutdown of each switch tube in each bridge arm is generated and applied to the corresponding switch tube.

8. The fault-tolerant control system of the magnetic levitation expansion generator controller according to claim 7, characterized in that: The short-circuit fault tolerance module identifies the short-circuit fault for controlling winding A. n and B n A set of switch tubes S 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 After a short circuit fault occurs, the current magnitude and current direction of each winding are calculated with the goal of making the resultant electromagnetic force generated by the two windings on each degree of freedom equal to a preset value, including the following steps: S1: Positioning switch tube S 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 There is a short-circuit fault in the switch tube. If it is used to control winding A n If the switch tube is on, it will transfer to S2; otherwise, it will transfer to S3; S2: Set winding A1~A n The current magnitude is equal to the original current magnitude, and the current direction is opposite to the original current direction, and the winding A is set n+1 ~A N The current magnitude is equal to the original current magnitude, and the current direction is the same as the original current direction. The resultant electromagnetic force generated by the two windings on each degree of freedom is taken as the preset value as the target. Calculate the windings B1~B N The magnitude and direction of the current; S3: Set winding B1~B n The current magnitude of the winding B is equal to the original current magnitude and the current direction is opposite to the original current direction. n+1 ~B N The current magnitude is equal to the original current magnitude, and the current direction is the same as the original current direction. The resultant electromagnetic force generated by the two windings on each degree of freedom is taken as the preset value as the target. Calculate the windings A1~A N The magnitude and direction of the current; The original current magnitude and original current direction of the winding respectively represent the current magnitude and current direction of the winding under normal working conditions.

9. The fault-tolerant control system of the magnetic levitation expansion generator controller according to claim 7 or 8, characterized in that: In step S1, the switch tube S is positioned. 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 The switch tubes with short circuit faults include: Monitoring bridge arm L n , L n+1 , L n+N and L n+N+1 Voltage command value; If the bridge arm L n The voltage command value decreases and eventually reaches negative saturation, then the switch tube S 2n-1 A short circuit fault occurs; If the bridge arm L n+1 The voltage command value increases and eventually reaches positive saturation, then the switch tube S 2n+2 A short circuit fault occurs; If the bridge arm L n+N The voltage command value decreases and eventually reaches negative saturation, then the switch tube S 2n+2N-1 A short circuit fault occurs; If the bridge arm L n+N+1 The voltage command value increases and eventually reaches positive saturation, then the switch tube S 2n+2N+2 A short circuit fault has occurred.

10. The fault-tolerant control system of the magnetic levitation expansion generator controller according to claim 7 or 8, characterized in that: Also includes: Open circuit fault identification module, used to detect winding A n and B n The current i an and i cn , and the sum of the two is less than the preset current threshold i limiit ″, it is determined that the winding A is used to control n and B n A set of switch tubes S 2n-1 , S 2n+2 , S 2n+2N-1 and S 2n+2N+2 There is a circuit breaker fault; Among them, i limiit ″ limiit ′.​

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