Search

CN-121984406-A - Double three-phase linear motor undisturbed fault-tolerant control method based on virtual current reconstruction

CN121984406ACN 121984406 ACN121984406 ACN 121984406ACN-121984406-A

Abstract

The invention provides a double three-phase linear motor undisturbed fault-tolerant control method based on virtual current reconstruction, belongs to the technical field of motor driving and control, and is suitable for the working condition of fast and impact-free switching under the condition that a motor has power supply faults. According to the method, after the power interruption fault of one set of three-phase power supply system is detected, only a single controller is used for controlling a normal side winding, the sampled normal side three-phase current is amplified in equal proportion, the fault side current is virtually set to zero, a virtual six-phase current signal is reconstructed, a feedback value is obtained through coordinate transformation, and meanwhile, the current reference value and PI parameters before the fault are kept unchanged, so that undisturbed switching from normal operation to fault-tolerant operation is achieved, and current overshoot can be effectively restrained. The invention has the advantages of simplifying the control system structure, reducing hardware resources, keeping good reliability and dynamic and static performance, and being suitable for linear motor driving occasions with higher requirements on reliability and continuity.

Inventors

  • XU FEI
  • WAN MINGCHANG
  • LI YAOHUA
  • LI ZIXIN
  • SHI LIMING
  • GE QIONGXUAN
  • WANG KE

Assignees

  • 中国科学院电工研究所

Dates

Publication Date
20260505
Application Date
20260120

Claims (10)

  1. 1. The undisturbed fault-tolerant control method for the double three-phase linear motor based on virtual current reconstruction is characterized by comprising the following steps of: step 1, fault detection and mode switching, namely monitoring power supply states of two sets of three-phase windings in real time, recognizing that a certain set of windings have power supply phase failure, and switching to a fault-tolerant operation mode; Step 2, current signal reconstruction, namely under fault tolerance mode, sampling only three-phase winding current which normally works, amplifying the three-phase winding current by k times in equal proportion, and virtually setting three-phase current at the fault side to zero at the same time, so as to reconstruct a group of complete virtual six-phase current signals; mapping the reconstructed virtual six-phase current signal to a stationary two-phase coordinate system alpha-beta plane containing an effective electromechanical energy conversion component through space vector decoupling VSD based coordinate transformation, and obtaining a direct current feedback value under a rotating coordinate system d-q plane through rotating transformation Park transformation; Step 4, maintaining the controller parameters, namely maintaining the current reference value set before the fault and the proportional integral PI regulator parameters unchanged in the whole fault-tolerant switching and running process; and 5, driving output and overshoot suppression, namely comparing the current feedback value obtained by the steps with the original reference value, generating a control signal through a PI regulator, and driving the residual three-phase winding to realize continuous and stable operation of the motor.
  2. 2. The method of claim 1, wherein step 2 comprises collecting only three-phase currents on the normal side Equal proportion of the three-phase current is amplified by k times, namely , , Virtually setting three-phase current at fault side to zero, namely , , Thereby reconstructing a set of virtual six-phase current vectors : (1)。
  3. 3. Method according to claim 2, characterized in that the amplification factor of the equal-ratio amplification is preferably k=2.
  4. 4. A method according to claim 3, characterized in that the transformation employed by the coordinate transformation is a transformation based on the theory of spatial decoupling, mapping the virtual six-phase current signal to a stationary two-phase coordinate system containing an effective electromechanical energy conversion component.
  5. 5. The method of claim 4, wherein the matrix of the space vector decoupling transformation, i.e., transformation into the effective electromechanical energy conversion α - β axis plane, is: (2) Wherein, the Phase angles which are phase differences of two sets of three-phase currents; The stator six-phase current signal is recorded as follows: ; The space vector decoupling transformation process comprises the following steps: (3) Wherein, the Representing the two-phase currents in the alpha-beta plane of the transformed stationary coordinate system, 、 Representing the current components in the alpha and beta axes in the alpha-beta plane, respectively.
  6. 6. The method of claim 5 further wherein the six-phase current signal when considering only three-phase currents in the first and second windings, respectively, is: , In the six-phase current signal, two sets of three-phase currents are staggered, and the two sets of three-phase currents are different by 30 degrees for example, namely =30°, And expresses sine alternating current in cosine form, so: (4) Wherein, the Representing the magnitude of the current flow, Representing the instantaneous phase angle of the current, decomposing the space vector decoupling transformation matrix into two matrices, (5) Wherein, the , ; Since the spatial decoupling transformation is a linear transformation, it will be considered as the sum of the contributions of the three phase currents in the two sets of windings: (6) Wherein, the And Representing the two-phase current components contributed by the first and second sets of winding currents, respectively; thus, when another set of three-phase currents is not considered, the individual contributions of each set of three-phase currents to the space vector decoupling transformed two-phase currents are: (7) (8) the total two-phase current after transformation is: (9) As shown in formulas (7) - (9), each set of three-phase current independently contributes to two-phase current and total two-phase current, and the following relation is satisfied: (10) namely, the two sets of three-phase currents respectively have the same contribution to the transformed total current, and the two sets of three-phase currents are exactly half of the transformed total current; therefore, when any one of the two sets of three-phase windings has an open-circuit fault, the physical current of the fault winding is practically zero, namely: (11) if the two-phase current converted under the fault condition is kept the same as that before the fault, the current of the normal side winding is amplified by one time according to the formula (10) to construct a virtual six-phase current Namely, the substitution formula (3) can be satisfied: (12) Wherein, the Representing the two-phase current in the α - β plane of the transformed stationary coordinate system.
  7. 7. The method of claim 6, wherein the coordinate transformation further comprises: component of current in the stationary two-phase coordinate system And converting the current feedback values to a coordinate system synchronously rotating with the magnetic field of the motor through rotation transformation to obtain direct-current d-axis and q-axis current feedback values.
  8. 8. The method of claim 7, wherein the matrix expression of the rotation transformation is: (13) Wherein, the Representing the two-phase current in the d-q plane of the rotating coordinate system after rotation transformation, 、 Representing the current components on the d-axis and the q-axis in the d-q plane respectively, Representing the instantaneous phase angle of the current.
  9. 9. An electronic device comprising one or more processors and a memory for storing one or more programs, wherein the one or more programs, when executed by the one or more processors, cause the one or more processors to implement the method of any of claims 1-8.
  10. 10. A computer readable storage medium having stored thereon executable instructions which when executed by a processor cause the processor to implement the method of any of claims 1 to 8.

Description

Double three-phase linear motor undisturbed fault-tolerant control method based on virtual current reconstruction Technical Field The invention relates to the technical field of motor driving and control, in particular to a double three-phase linear motor undisturbed fault-tolerant control method based on virtual current reconstruction. Background The double three-phase sectionalized power supply linear motor has the advantages of high thrust density, low torque pulsation, good fault tolerance performance and the like, and is widely applied to occasions with high reliability requirements, such as aerospace, precision machining, rail transit and other fields. The two independent three-phase windings can work cooperatively under normal conditions, so that the system performance is improved. However, when one of the three-phase power supply systems fails completely due to a fault, an open circuit or a short circuit of a driver, how to ensure that the motor continues to operate stably and reliably under the power supply of the remaining three-phase windings, namely "open-phase fault-tolerant control", becomes a key technical challenge in the field. At present, the fault-tolerant control method aiming at the phase failure of the double three-phase motor mainly comprises the following two ideas: The first is a dual controller based fault tolerance scheme. The scheme uses two independent controllers to control two sets of three-phase windings respectively under normal condition. When the open-phase fault occurs, the fault side controller is closed, and only the single controller at the normal side continues to work. The method has the advantages of simple control logic and inheritance of the mature control strategy of the three-phase motor. However, it has the significant disadvantage that the dual controllers cannot be decoupled from each other, the two controllers have adverse effects on each other in control, and secondly, the system hardware cost of this approach is high, redundant controllers and corresponding interface circuits are required, and at the moment of failover, current and thrust impacts may still be caused due to abrupt control architecture changes. The second type is a single controller fault tolerant scheme based on six-phase to two-phase (6-2) coordinate transformation. The scheme tries to map the residual three-phase system after the fault to a virtual two-phase coordinate system for unified control through mathematical transformation, so that one controller is saved. However, the prior proposal has a key defect that the mathematical model of the motor before and after the fault is radically changed, and if the control parameter before the fault is directly used, the control system is unstable or the performance is deteriorated. Thus, these schemes typically require that the current reference be dynamically recalculated and switched after a fault occurs, and that the parameters of the Proportional Integral (PI) regulator be reset. The online adjustment process not only increases the complexity of an algorithm, but also is more important in that during the transient process of parameter switching, overshoot or oscillation of phase current is extremely easy to cause, stress impact is caused on a motor body and a power device, the safety of a system is threatened, and the aim of pursuing high reliability in fault-tolerant control is contrary to the aim of pursuing high reliability. In addition to the above, the patent CN120073613a proposes to cope with short-circuit/open-circuit faults by means of topology switching, and the patent CN119362954A proposes to diagnose faults by comparing current estimated values of a current observer with actual sampling values, and to replace actual fault currents with estimated currents to realize redundancy control. Both of these methods are cumbersome and complex, and especially when the motor is operated at high speed, there may be a problem that the response speed is not fast enough. Disclosure of Invention In order to solve the technical problems, the invention provides a double three-phase linear motor undisturbed fault-tolerant control method based on virtual current reconstruction. The method aims to realize smooth switching and stable operation under the fault condition, and meanwhile, the simplicity and parameter consistency of a control structure are maintained. In order to achieve the above purpose, the invention adopts the following technical scheme: A double three-phase linear motor undisturbed fault-tolerant control method based on virtual current reconstruction includes the following steps that the input of a motor is double three-phase current: step 1, fault detection and mode switching, namely monitoring power supply states of two sets of three-phase windings in real time, recognizing that a certain set of windings have power supply phase failure, and switching to a fault-tolerant operation mode; Step 2, current signal reconstruction, namely und