Method for detecting residual magnetism of motor, re-throw control method, device and storage medium

Abstract

The application discloses a motor residual magnetism detection method, a motor re-throw control method, equipment and a storage medium. The method comprises the following steps: acquiring a current in a short-circuit state of a motor; determining a magnetic chain change value after a short-circuit operation of the motor and an initial value of a magnetic chain at a short-circuit time according to the current; constructing a rotor magnetic chain detection model of the motor after the short-circuit operation according to the magnetic chain change value and the initial value of the magnetic chain; controlling the motor to be open-circuit within a preset time period, and determining a rotor magnetic chain at an open-circuit end time of the motor according to the rotor magnetic chain detection model; and determining a stator magnetic chain of the motor according to the rotor magnetic chain at the open-circuit end time of the motor, so as to take the rotor magnetic chain at the open-circuit end time of the motor and the stator magnetic chain of the motor as initial magnetic chains and perform re-throw control on the motor. When the motor residual magnetism is detected by using the method, the motor speed no longer has an influence, and the detection precision of the motor residual magnetism is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of motor control, and particularly relates to a motor residual magnetism detection method, a restart control method, equipment and a storage medium. BACKGROUND

[0002] During the operation of an induction motor, sudden stop may occur due to power interruption or failure and the like. At this time, although the motor stator current rapidly decreases to zero, the rotor loop of the induction motor still has current. The rotor loop current will decay exponentially, and the decay speed is the rotor time constant. Due to the existence of the rotor current, the motor stator-rotor flux also exists. If the motor is in a rotating state, the stator magnetic field will also generate a voltage at the motor output end, which is called stator power loss residual voltage. If the motor still has residual magnetic field and stator power loss residual voltage when the motor is restarted, and the control system does not process it, a severe impact current and impact torque may be generated, so it is necessary to detect the motor residual magnetism during the restart process to avoid the occurrence of current and torque impact.

[0003] In order to avoid the impact, there are two methods at present, one is to wait for a certain time to realize that the motor residual magnetic field decays below a certain amplitude, but this may cause the system power to be missing within a certain time. The other method is to estimate the motor flux after power failure according to the variation law of the motor magnetic field and the motor speed and power-off time. However, this method is obviously affected by the motor speed accuracy, and in a high-power traction drive system, the speed accuracy is low, and the cumulative speed error may bring a large position deviation, affecting the effect of restart.

[0004] Therefore, how to improve the detection accuracy of motor residual magnetism is a technical problem to be solved by those skilled in the art. SUMMARY

[0005] The main purpose of the present application is to provide a motor residual magnetism detection method, a restart control method, equipment and a storage medium, to solve the problem of low detection accuracy of motor residual magnetism in the prior art.

[0006] In view of the above problems, the present application provides a motor residual magnetism detection method, comprising:

[0007] Obtaining the current in the short-circuit state of the motor;

[0008] According to the current, determining the magnetic chain change value after the motor short-circuit operation and the magnetic chain initial value at the motor short-circuit time;

[0009] According to the magnetic chain change value and the magnetic chain initial value, a rotor magnetic chain detection model of the motor after the motor short-circuit operation is constructed;

[0010] controlling the motor to be open-circuited for a preset time period, and determining a rotor flux linkage at a time when the motor open-circuit ends according to the rotor flux linkage detection model;

[0011] determining a stator flux linkage of the motor according to the rotor flux linkage at the time when the motor open-circuit ends.

[0012] Further, in the motor residual magnetism detection method, the current includes a first-phase current, a second-phase current and a third-phase current; the flux linkage change value includes a first flux linkage change value component and a second flux linkage change value component; and the initial flux linkage value includes a first initial flux linkage value component and a second initial flux linkage value component.

[0013] determining the flux linkage change value after the motor short-circuit operation and the initial flux linkage value at the time when the motor is short-circuited according to the current, including:

[0014] transforming the first-phase current, the second-phase current and the third-phase current to obtain a first current component and a second current component in a motor short-circuit state;

[0015] obtaining the flux linkage change value and the initial flux linkage value according to the first current component and the second current component.

[0016] Further, in the motor residual magnetism detection method, transforming the first-phase current, the second-phase current and the third-phase current to obtain a first current component and a second current component in a motor short-circuit state, including:

[0017] substituting the first-phase current, the second-phase current and the third-phase current into a preset first calculation formula to obtain the first current component and the second current component in the motor short-circuit state; the first calculation formula is:

[0018]

[0019] wherein, i a represents the first-phase current, i b represents the second-phase current, i c represents the third-phase current, i sα represents the first current component, i sβ represents the second current component.

[0020] Further, in the motor residual magnetism detection method, obtaining the flux linkage change value and the initial flux linkage value according to the first current component and the second current component, including:

[0021] The first current component and the second current component are substituted into a preset second calculation formula to obtain the flux linkage change value, and the first current component and the second current component are substituted into a preset third calculation formula or a ninth calculation formula to obtain the initial value of the flux linkage.

[0022] The second calculation formula is:

[0023]

[0024] wherein, Δψ rα represents the first flux linkage change value component, Δψ rβ represents the second flux linkage change value component, R s represents a stator resistance, L s represents a stator inductance, L r represents a rotor inductance, L m represents an excitation inductance, and σ represents a leakage coefficient.

[0025] The third calculation formula is:

[0026]

[0027] wherein, ψ rα0 represents the first initial value of the flux linkage component, ψ rβ0 represents the second initial value of the flux linkage component, R r represents a rotor time constant, ω m represents a rotor angular frequency.

[0028] The ninth calculation formula is:

[0029]

[0030] Further, in the motor residual magnetism detection method described above, a fourth calculation formula corresponding to the rotor flux linkage detection model is:

[0031]

[0032] wherein, ψ rα (t i ) represents a first rotor flux linkage component corresponding to a t i moment after the motor short-circuit operation, ψ rβ (t i ) represents a second rotor flux linkage component corresponding to a t i moment after the motor short-circuit operation.

[0033] Further, in the motor residual magnetism detection method described above, the rotor flux linkage detection model is used to determine the rotor flux linkage at the end of the open circuit of the motor, including:

[0034] According to the rotor flux linkage detection model, the rotor flux linkage at the motor open circuit starting time is determined;

[0035] According to the rotor flux linkage at the motor open circuit starting time, the first rotor flux linkage amplitude and the first rotor flux linkage phase angle of the motor at the motor open circuit starting time are determined;

[0036] According to the first rotor flux linkage amplitude and the first rotor flux linkage phase angle, the second rotor flux linkage amplitude and the second rotor flux linkage phase angle of the motor at the motor open circuit maintenance time are determined; wherein the motor open circuit maintenance time is the time corresponding to the preset time period;

[0037] According to the second rotor flux linkage amplitude and the second rotor flux linkage phase angle, the rotor flux linkage at the motor open circuit ending time is determined.

[0038] Further, in the motor residual magnetism detection method described above, the rotor flux linkage at the motor open circuit starting time includes a third rotor flux linkage component at the motor open circuit starting time and a fourth rotor flux linkage component at the motor open circuit starting time;

[0039] According to the rotor flux linkage at the motor open circuit starting time, the first rotor flux linkage amplitude and the first rotor flux linkage phase angle of the motor at the motor open circuit starting time are determined, including:

[0040] The first rotor flux linkage component and the second rotor flux linkage component are substituted into a preset fifth calculation formula to obtain the first rotor flux linkage amplitude and the first rotor flux linkage phase angle;

[0041] The fifth calculation formula is:

[0042]

[0043] Wherein, ψ r1 represents the first rotor flux linkage amplitude, ψ rα (t1) represents the third rotor flux linkage component, ψ rβ (t1) represents the fourth rotor flux linkage component, θ r1 represents the first rotor flux linkage phase angle.

[0044] Further, in the motor residual magnetism detection method described above, according to the first rotor flux linkage amplitude and the first rotor flux linkage phase angle, the second rotor flux linkage amplitude and the second rotor flux linkage phase angle of the motor at the motor open circuit maintenance time are determined, including:

[0045] The first rotor flux linkage amplitude and the first rotor flux linkage phase angle are substituted into a preset sixth calculation formula to obtain the second rotor flux linkage amplitude and the second rotor flux linkage phase angle;

[0046] The sixth calculation formula is:

[0047]

[0048] wherein ψ r2 represents the second rotor flux magnitude, R r represents the rotor time constant, L r represents the rotor inductance, θ r2 represents the second rotor flux angle, t1 represents the open-circuit start time of the motor, t2 represents the open-circuit end time of the motor, T2 represents the open-circuit maintenance time of the motor, ω m represents the rotor angular frequency.

[0049] Further, in the motor residual magnetism detection method described above, the rotor flux at the open-circuit end time of the motor includes a fifth rotor flux component at the open-circuit end time of the motor and a sixth rotor flux component at the open-circuit end time of the motor.

[0050] According to the second rotor flux magnitude and the second rotor flux angle, the rotor flux at the open-circuit end time of the motor is determined, including:

[0051] The second rotor flux magnitude and the second rotor flux angle are substituted into a preset seventh calculation formula to determine the rotor flux at the open-circuit end time of the motor.

[0052] The seventh calculation formula is:

[0053]

[0054] wherein ψ rα (t2) represents the fifth rotor flux component, ψ rβ (t2) represents the sixth rotor flux component.

[0055] Further, in the motor residual magnetism detection method described above, the stator flux of the motor includes a first stator flux component and a second stator flux component.

[0056] According to the rotor flux at the open-circuit end time of the motor, the stator flux of the motor is determined, including:

[0057] The rotor flux at the open-circuit end time of the motor is substituted into a preset eighth calculation formula to calculate the first stator flux component and the second stator flux component.

[0058] The eighth calculation formula is:

[0059]

[0060] wherein ψ sα (t2) represents the first stator flux component, ψ sβ(t2) represents the second stator flux linkage component, L m represents the excitation inductance.

[0061] The application further provides a motor restart control method, comprising:

[0062] The motor residual magnetism detection method provided in any one of the above solutions, the rotor flux linkage at the motor open circuit end time and the stator flux linkage of the motor are obtained.

[0063] The rotor flux linkage at the motor open circuit end time and the stator flux linkage of the motor are taken as initial flux linkages, and the motor is controlled to restart.

[0064] The application further provides a motor residual magnetism detection device, comprising a memory and a controller, the memory stores a computer program, and the computer program is executed by the controller to realize the motor residual magnetism detection method provided in any one of the above solutions.

[0065] The application further provides a storage medium, the storage medium stores a computer program, and the computer program is executed by a controller to realize the motor residual magnetism detection method provided in any one of the above solutions.

[0066] Compared with the prior art, one or more of the above solutions can have the following advantages or beneficial effects:

[0067] The motor residual magnetism detection method, the restart control method, the device and the storage medium provided by the application can obtain the current in the motor short circuit state, determine the flux linkage change value after the motor short circuit operation and the initial value of the flux linkage at the motor short circuit time according to the current, construct the rotor flux linkage detection model of the motor after the motor short circuit operation according to the flux linkage change value and the initial value of the flux linkage, realize the dynamic construction of the rotor flux linkage detection model, control the motor to be open in a preset time period after the rotor flux linkage detection model is constructed, determine the rotor flux linkage at the motor open circuit end time according to the rotor flux linkage detection model, determine the stator flux linkage of the motor according to the rotor flux linkage at the motor open circuit end time, and control the motor to restart with the rotor flux linkage at the motor open circuit end time and the stator flux linkage of the motor as initial flux linkages. When the motor residual magnetism is detected by using the method, the motor speed no longer has an influence, and the detection accuracy of the motor residual magnetism is improved.

[0068] Other features and advantages of the application will be set forth in the following description, and in part will become apparent to those skilled in the art upon examination of the following or can be learned by practice of the application. The objects and other advantages of the application can be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings. BRIEF DESCRIPTION OF DRAWINGS

[0069] The accompanying drawings, which are included to provide a further understanding of the application and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings:

[0070] Figure 1 a flow chart of an embodiment of the method for detecting residual magnetism of an electric machine according to the present application;

[0071] Figure 2 a structural schematic diagram of an embodiment of the device for detecting residual magnetism of an electric machine according to the present application;

[0072] Figure 3 a structural schematic diagram of an embodiment of the device for detecting residual magnetism of an electric machine according to the present application. DETAILED DESCRIPTION

[0073] The embodiments of the present application will be described in detail below with reference to the drawings and embodiments, so that how the present application applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented. It should be noted that, as long as there is no conflict, each embodiment in the present application and each feature in each embodiment can be combined with each other, and the technical solutions formed thereby are all within the protection scope of the present application.

[0074] Figure 1 a flow chart of an embodiment of the method for detecting residual magnetism of an electric machine according to the present application, as shown in Figure 1 the method for detecting residual magnetism of an electric machine according to the present embodiment can specifically include the following steps:

[0075] 100, acquiring a current in a short-circuit state of an electric machine;

[0076] In one specific implementation process, the control system can send a zero vector pulse to the traction converter, so that the windings of the electric machine are short-circuited together. The specific short-circuit method can make each upper tube of the inverter conductive, or make each lower tube of the inverter conductive.

[0077] In the short-circuit state of the electric machine, the first-phase current, the second-phase current and the third-phase current of the electric machine can be collected, or two-phase currents can be collected, and the current of the other phase can be calculated.

[0078] 101, determining a flux linkage change value after the short-circuit operation of the electric machine and a flux linkage initial value at the short-circuit time of the electric machine according to the current;

[0079] In one specific implementation process, the flux linkage change value includes a first flux linkage change value component and a second flux linkage change value component; and the flux linkage initial value includes a first flux linkage initial value component and a second flux linkage initial value component.

[0080] In one specific implementation, the first phase current, the second phase current and the third phase current are transformed to obtain a first current component and a second current component in a short-circuit state of the motor; and the flux linkage change value and the initial value of the flux linkage are obtained according to the first current component and the second current component.

[0081] Specifically, the first phase current, the second phase current and the third phase current can be substituted into a preset first calculation formula to obtain the first current component and the second current component in the short-circuit state of the motor; the first current component and the second current component can be substituted into a preset second calculation formula to obtain the flux linkage change value, and the first current component and the second current component can be substituted into a preset third calculation formula to obtain the initial value of the flux linkage.

[0082] The first calculation formula is:

[0083]

[0084] wherein, i a represents the first phase current, i b represents the second phase current, i c represents the third phase current, i sα represents the first current component, i sβ represents the second current component.

[0085] The second calculation formula is:

[0086]

[0087] wherein, Δψ rα represents the first flux linkage change value component, Δψ rβ represents the second flux linkage change value component, R s represents a stator resistance, L s represents a stator inductance, L r represents a rotor inductance, L m represents an excitation inductance, and σ represents a leakage coefficient.

[0088] The third calculation formula is:

[0089]

[0090] wherein, ψ rα0 represents the first flux linkage initial value component, ψ rβ0 represents the second flux linkage initial value component, R r represents a rotor time constant, ω m represents a rotor angular frequency.

[0091] The ninth calculation formula is:

[0092]

[0093] 102. constructing a rotor flux detection model of the motor after the short-circuit operation of the motor according to the change value of the flux linkage and the initial value of the flux linkage;

[0094] In one specific implementation process, the fourth calculation formula corresponding to the rotor flux detection model is:

[0095]

[0096] wherein ψ rα (t i ) represents the first rotor flux component at t i moment after the short-circuit operation of the motor, and ψ rβ (t i ) represents the second rotor flux component at t i moment after the short-circuit operation of the motor.

[0097] 103. controlling the motor to be open-circuit for a preset time period, and determining the rotor flux at the end moment of the open-circuit operation of the motor according to the rotor flux detection model;

[0098] In one specific implementation process, after the rotor flux detection model is constructed, the motor can be controlled to be open-circuit for a relatively short preset time period, and then the rotor flux at the end moment of the open-circuit operation of the motor is determined according to the rotor flux detection model. The rotor flux at the start moment of the open-circuit operation of the motor includes the first rotor flux component at the start moment of the open-circuit operation of the motor and the second rotor flux component at the start moment of the open-circuit operation of the motor.

[0099] Specifically, the step of determining the rotor flux at the end moment of the open-circuit operation of the motor according to the rotor flux detection model is as follows:

[0100] (1) determining the rotor flux at the start moment of the open-circuit operation of the motor according to the rotor flux detection model;

[0101] Specifically, since the open-circuit operation of the motor is located after the short-circuit operation of the motor, the rotor flux at the end moment of the open-circuit operation of the motor is suitable for the rotor flux detection model constructed in the foregoing, so that the first rotor flux component at the start moment of the open-circuit operation of the motor and the second rotor flux component at the start moment of the open-circuit operation of the motor can be obtained. The first rotor flux component at the start moment of the open-circuit operation of the motor is denoted as ψ rα (t1), and the second rotor flux component at the start moment of the open-circuit operation of the motor is denoted as ψ rβ (t1).

[0102] (2) determining the first rotor flux amplitude and the first rotor flux phase angle of the motor at the start moment of the open-circuit operation of the motor according to the rotor flux at the start moment of the open-circuit operation of the motor;

[0103] Specifically, the first rotor flux linkage component and the second rotor flux linkage component can be substituted into a preset fifth calculation formula to obtain the first rotor flux linkage amplitude and the first rotor flux linkage phase angle.

[0104] The fifth calculation formula is:

[0105]

[0106] wherein, ψ r1 represents the first rotor flux linkage amplitude, ψ rα (t1) represents the third rotor flux linkage component, ψ rβ (t1) represents the fourth rotor flux linkage component, θ r1 represents the first rotor flux linkage phase angle.

[0107] (3) determining, according to the first rotor flux linkage amplitude and the first rotor flux linkage phase angle, a second rotor flux linkage amplitude and a second rotor flux linkage phase angle of the motor at a motor open circuit maintaining time.

[0108] In one specific implementation process, the motor open circuit maintaining time is a time corresponding to the preset time period. The first rotor flux linkage amplitude and the first rotor flux linkage phase angle can be substituted into a preset sixth calculation formula to obtain the second rotor flux linkage amplitude and the second rotor flux linkage phase angle.

[0109] The sixth calculation formula is:

[0110]

[0111] wherein, ψ r2 represents the second rotor flux linkage amplitude, R r represents a rotor time constant, L r represents a rotor inductance, θ r2 represents the second rotor flux linkage phase angle, t1 represents the motor open circuit starting time, t2 represents the motor open circuit ending time, T2 represents the motor open circuit maintaining time, ω m represents a rotor angular frequency.

[0112] (4) determining, according to the second rotor flux linkage amplitude and the second rotor flux linkage phase angle, a rotor flux linkage at a motor open circuit ending time.

[0113] In one specific implementation process, the rotor flux linkage at the motor open circuit ending time includes a fifth rotor flux linkage component at the motor open circuit ending time and a sixth rotor flux linkage component at the motor open circuit ending time. The second rotor flux linkage amplitude and the second rotor flux linkage phase angle can be substituted into a preset seventh calculation formula to determine the rotor flux linkage at the motor open circuit ending time.

[0114] The seventh calculation formula is:

[0115]

[0116] wherein ψ rα (t2) represents the fifth rotor flux linkage component, ψ rβ (t2) represents the sixth rotor flux linkage component.

[0117] 104. determining the stator flux linkage of the motor according to the rotor flux linkage at the motor open circuit end time.

[0118] In one specific implementation process, the stator flux linkage of the motor includes a first stator flux linkage component and a second stator flux linkage component. The rotor flux linkage at the motor open circuit end time can be substituted into a preset eighth calculation formula to calculate the first stator flux linkage component and the second stator flux linkage component;

[0119] The eighth calculation formula is:

[0120]

[0121] wherein ψ sα (t2) represents the first stator flux linkage component, ψ sβ (t2) represents the second stator flux linkage component, L m represents the excitation inductance.

[0122] In one specific implementation process, after obtaining the rotor flux linkage at the motor open circuit end time and the stator flux linkage of the motor, the rotor flux linkage at the motor open circuit end time and the stator flux linkage of the motor can be used as the initial flux linkage of the existing control system. The control system processes the rotor flux linkage at the motor open circuit end time and the stator flux linkage of the motor, which can avoid the overcurrent problem in the reclosing process and solve the torque impulse problem in the reclosing process.

[0123] The motor residual magnetism detection method of the embodiment, by acquiring the current in the motor short-circuit state, determining the flux linkage change value after the motor short-circuit operation and the initial value of the flux linkage at the motor short-circuit moment according to the current, constructing the rotor flux linkage detection model of the motor after the motor short-circuit operation according to the flux linkage change value and the initial value of the flux linkage, realizes the dynamic construction of the rotor flux linkage detection model, and after the rotor flux linkage detection model is constructed, the motor is controlled to be open-circuit in a preset time period, and the rotor flux linkage at the motor open-circuit end moment is determined according to the rotor flux linkage detection model. The stator flux linkage of the motor is determined according to the rotor flux linkage at the motor open-circuit end moment, so as to take the rotor flux linkage at the motor open-circuit end moment and the stator flux linkage of the motor as the initial flux linkage, and the motor is controlled to be re-energized. When the motor residual magnetism is detected by using the method, the motor speed no longer has an influence, and the detection precision of the motor residual magnetism is improved.

[0124] It should be noted that the method of the embodiment of the application can be executed by a single device, such as a computer or a server. The method of the embodiment can also be applied to a distributed scenario and completed by multiple devices in cooperation. In the distributed scenario, one of the multiple devices can only execute one or more steps in the method of the embodiment of the application, and the multiple devices can interact with each other to complete the method.

[0125] Based on the inventive concept of the motor residual magnetism detection method of the above embodiment, the application further provides a motor re-energizing control method, comprising:

[0126] Based on the motor residual magnetism detection method of the above embodiment, the rotor flux linkage at the motor open-circuit end moment and the stator flux linkage of the motor are obtained.

[0127] The rotor flux linkage at the motor open-circuit end moment and the stator flux linkage of the motor are taken as the initial flux linkage, and the motor is controlled to be re-energized.

[0128] Figure 2 The structure diagram of the motor residual magnetism detection device embodiment of the application is shown in FIG. 1. Figure 2 As shown in FIG. 1, the motor residual magnetism detection device of the embodiment can include an acquisition module 20, a first determination module 21, a construction module 22, a second determination module 23, and a third determination module 24.

[0129] The acquisition module 20 is configured to acquire the current in the motor short-circuit state.

[0130] The current in the motor short-circuit state can include the first-phase current, the second-phase current, and the third-phase current.

[0131] The first determination module 21 is configured to determine the flux linkage change value after the motor short-circuit operation and the initial value of the flux linkage at the motor short-circuit moment according to the current.

[0132] In one specific implementation, the flux linkage change value includes a first flux linkage change value component and a second flux linkage change value component; and the initial flux linkage value includes a first initial flux linkage value component and a second initial flux linkage value component. The first phase current, the second phase current, and the third phase current can be transformed to obtain a first current component and a second current component in the short-circuit state of the motor; and the first current component and the second current component are used to obtain the flux linkage change value and the initial flux linkage value.

[0133] Specifically, the first phase current, the second phase current, and the third phase current can be substituted into a preset first calculation formula to obtain the first current component and the second current component in the short-circuit state of the motor; the first current component and the second current component are substituted into a preset second calculation formula to obtain the flux linkage change value; and the first current component and the second current component are substituted into a preset third calculation formula or a ninth calculation formula to obtain the initial flux linkage value.

[0134] The first calculation formula to the third calculation formula and the ninth calculation formula can refer to the related descriptions above, and will not be described herein again.

[0135] The construction module 22 is configured to construct a rotor flux linkage detection model of the motor after the short-circuit operation of the motor according to the flux linkage change value and the initial flux linkage value.

[0136] In one specific implementation, a fourth calculation formula corresponding to the rotor flux linkage detection model can refer to the related descriptions above, and will not be described herein again.

[0137] The second determination module 23 is configured to control the motor to be open-circuited for a preset time period, and determine a rotor flux linkage at an open-circuit end time of the motor according to the rotor flux linkage detection model.

[0138] In one specific implementation, the second determination module 23 determines the rotor flux linkage at the open-circuit end time of the motor according to the following steps:

[0139] (1) determining a rotor flux linkage at an open-circuit start time of the motor according to the rotor flux linkage detection model;

[0140] In one specific implementation, the rotor flux linkage at the open-circuit start time of the motor includes a third rotor flux linkage component at the open-circuit start time of the motor and a fourth rotor flux linkage component at the open-circuit start time of the motor.

[0141] (2) determining a first rotor flux linkage amplitude and a first rotor flux linkage phase angle of the motor at the open-circuit start time of the motor according to the rotor flux linkage at the open-circuit start time of the motor;

[0142] The first rotor flux linkage component and the second rotor flux linkage component can be substituted into a preset fifth calculation formula to obtain the first rotor flux linkage amplitude and the first rotor flux linkage phase angle.

[0143] The fifth calculation formula can refer to the related description in the foregoing embodiments, and details are not described herein again.

[0144] (3) According to the first rotor flux linkage amplitude and the first rotor flux linkage phase angle, a second rotor flux linkage amplitude and a second rotor flux linkage phase angle of the motor at a motor open circuit maintaining time are determined, wherein the motor open circuit maintaining time is a time corresponding to the preset time period.

[0145] The first rotor flux linkage amplitude and the first rotor flux linkage phase angle can be substituted into a preset sixth calculation formula to obtain the second rotor flux linkage amplitude and the second rotor flux linkage phase angle.

[0146] The sixth calculation formula can refer to the related description in the foregoing embodiments, and details are not described herein again.

[0147] (4) According to the second rotor flux linkage amplitude and the second rotor flux linkage phase angle, a rotor flux linkage at a motor open circuit end time is determined.

[0148] In one specific implementation process, the rotor flux linkage at the motor open circuit end time includes a fifth rotor flux linkage component at the motor open circuit end time and a sixth rotor flux linkage component at the motor open circuit end time. The second rotor flux linkage amplitude and the second rotor flux linkage phase angle can be substituted into a preset seventh calculation formula to determine the rotor flux linkage at the motor open circuit end time.

[0149] The seventh calculation formula can refer to the related description in the foregoing embodiments, and details are not described herein again.

[0150] The third determination module 24 is configured to determine a stator flux linkage of the motor according to the rotor flux linkage at the motor open circuit end time.

[0151] In one specific implementation process, the stator flux linkage of the motor includes a first stator flux linkage component and a second stator flux linkage component. The rotor flux linkage at the motor open circuit end time can be substituted into a preset eighth calculation formula to obtain the first stator flux linkage component and the second stator flux linkage component.

[0152] The eighth calculation formula can refer to the related description in the foregoing embodiments, and details are not described herein again.

[0153] The apparatuses in the foregoing embodiments are used to implement the corresponding methods in the foregoing embodiments, and the specific implementation schemes can refer to the related description in the methods and the method embodiments, and have the beneficial effects of the corresponding method embodiments, which are not described herein again.

[0154] Figure 3 For the structural schematic diagram of the residual magnetism detection device of the electric machine of the present application, as shown in Figure 3 The traction system includes a memory 30 and a controller 31, the memory 30 stores a computer program, and the computer program is executed by the controller 31 to realize the fault detection method of the water pressure sensor of the above-mentioned embodiment.

[0155] The present application also provides a storage medium, the storage medium stores a computer program, and the computer program is executed by the controller to realize the fault detection method of the water pressure sensor of the above-mentioned embodiment.

[0156] It can be understood that the same or similar parts in the above-mentioned embodiments can be mutually referred to, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

[0157] It should be noted that in the description of the present application, the terms "first", "second", etc. are only for the purpose of description, and cannot be understood as indicating or implying relative importance. In addition, in the description of the present application, unless otherwise specified, the meaning of "a plurality of" is at least two.

[0158] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0159] Any process or method descriptions in flow charts or otherwise described herein represent embodiments of examples that can be implemented by executable instructions or computer program code stored on computer-readable media. Such instructions can be referred to as a "module" or "component". In the same manner, any process or method can be understood as a module or portion of a module that includes one or more executable instructions or computer program code for implementing specific logic functions or steps of the process. The scope of preferred embodiments of the present application encompasses not only the described embodiments but also equivalent ones that are not explicitly described. Equivalent ones include not only the equivalents of the described embodiments but also equivalents of the equivalents. The scope of the present application encompasses not only the described embodiments but also equivalents of the described embodiments.

[0160] It should be understood that each part of the present application can be realized by hardware, software, firmware or their combination. In the above-mentioned embodiments, a plurality of steps or methods can be realized by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if realized by hardware, and as in another embodiment, it can be realized by any one or their combination of the following technologies known in the art: discrete logic circuit with logic gate circuit for implementing logic function on data signal, application specific integrated circuit with suitable combination logic gate circuit, programmable gate array (PGA), field programmable gate array (FPGA) and the like.

[0161] Those skilled in the art of the present technology can understand that all or part of the steps carried out by the above-mentioned embodiment method can be completed by a program instructing the relevant hardware, and the program can be stored in a computer readable storage medium. When the program is executed, it includes one of the steps of the method embodiment or a combination thereof.

[0162] In addition, each functional unit in each embodiment of the present application can be integrated in one processing module, or each unit can exist physically separately, or two or more units can be integrated in one module. The integrated module can be realized in the form of hardware or in the form of a software functional module. When the integrated module is realized in the form of a software functional module and sold or used as an independent product, it can also be stored in a computer readable storage medium.

[0163] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0164] Although the disclosed embodiments of the present application are as above, the content described is only for the purpose of facilitating understanding of the embodiments adopted by the present application, and is not intended to limit the present application. Any person skilled in the art of the present application can make any modification and change in the form of implementation and details without departing from the spirit and scope of the present application disclosed, but the protection scope of the present application shall be subject to the scope defined by the appended claims.

Claims

1. A method for detecting residual magnetism in a motor, characterized in that, include: Obtain the current of the motor under short-circuit conditions; Based on the current, determine the change in flux linkage after the motor short-circuit operation and the initial flux linkage value at the moment of motor short-circuit. Based on the flux linkage change value and the initial flux linkage value, a rotor flux linkage detection model of the motor after the motor short-circuit operation is constructed. The motor is controlled to be open-circuited within a preset time period, and the rotor flux linkage at the end of the motor open-circuit detection time is determined according to the rotor flux linkage detection model. The stator flux linkage of the motor is determined based on the rotor flux linkage at the moment the open circuit of the motor ends.

2. The method for detecting residual magnetism in a motor according to claim 1, characterized in that, The current includes a first phase current, a second phase current, and a third phase current; the flux linkage change value includes a first flux linkage change value component and a second flux linkage change value component; the initial flux linkage value includes a first flux linkage initial value component and a second flux linkage initial value component. Based on the current, determine the flux linkage change after the motor short-circuit operation and the initial flux linkage value at the moment of motor short-circuit, including: The first phase current, the second phase current, and the third phase current are transformed to obtain the first current component and the second current component under the short-circuit state of the motor. The flux linkage change value and the initial flux linkage value are obtained based on the first current component and the second current component.

3. The method for detecting residual magnetism in a motor according to claim 2, characterized in that, The first phase current, the second phase current, and the third phase current are transformed to obtain the first current component and the second current component under the short-circuit state of the motor, including: Substituting the first phase current, the second phase current, and the third phase current into a preset first calculation formula, the first current component and the second current component under the short-circuit state of the motor are obtained; the first calculation formula is: Among them, i a i represents the first phase current. b i represents the second phase current. c Indicates the third phase current, i sα i represents the first current component. sβ This represents the second current component.

4. The method for detecting residual magnetism in a motor according to claim 3, characterized in that, The flux linkage change value and the initial flux linkage value are obtained based on the first current component and the second current component, including: The first current component and the second current component are substituted into a preset second calculation formula to calculate the change value of the magnetic flux, and the first current component and the second current component are substituted into a preset third calculation formula or a preset ninth calculation formula to calculate the initial value of the magnetic flux. The second calculation formula is: Where, Δψ rα The first magnetic flux change component, Δψ rβ R represents the component of the second flux linkage change value. s L represents the stator resistance. s L represents the stator inductance. r L represents the rotor inductance. m σ represents the magnetizing inductance, and σ represents the leakage flux coefficient. The third calculation formula is: Where, ψ rα0 ψ represents the initial value component of the first magnetic flux linkage. rβ0 R represents the initial value component of the second magnetic flux linkage. r ω represents the rotor time constant. m Indicates the rotor angular frequency; The ninth calculation formula is:

5. The method for detecting residual magnetism in a motor according to claim 2, characterized in that, The fourth calculation formula corresponding to the rotor flux linkage detection model is: Where, ψ rα (t i ) indicates the time after the motor is short-circuited. i The first rotor flux component corresponding to time ψ rβ (t i ) indicates the time after the motor is short-circuited. i The second rotor flux component corresponding to the time.

6. The method for detecting residual magnetism in a motor according to claim 1, characterized in that, According to the rotor flux linkage detection model, the rotor flux linkage at the end of the open circuit of the fixed motor includes: Based on the rotor flux linkage detection model, determine the rotor flux linkage at the start of the motor open circuit. Based on the rotor flux linkage at the start of the open circuit of the motor, determine the amplitude and phase angle of the first rotor flux linkage of the motor at the start of the open circuit. The second rotor flux amplitude and the second rotor flux phase angle of the motor are determined based on the first rotor flux amplitude and the first rotor flux phase angle; wherein, the motor open circuit maintenance time is the time corresponding to the preset time period; The rotor flux linkage at the end of the motor open circuit is determined based on the amplitude and phase angle of the second rotor flux linkage.

7. The method for detecting residual magnetism in a motor according to claim 6, characterized in that, The rotor flux linkage at the start of the motor open circuit includes a third rotor flux linkage component and a fourth rotor flux linkage component at the start of the motor open circuit. Based on the rotor flux linkage at the start of the open circuit of the motor, determine the amplitude and phase angle of the first rotor flux linkage at the start of the open circuit, including: Substitute the first rotor flux component and the second rotor flux component into the preset fifth calculation formula to calculate the first rotor flux amplitude and the first rotor flux phase angle. The fifth calculation formula is: Where, ψ r1 ψ represents the amplitude of the first rotor flux linkage. rα (t1) represents the third rotor flux component, ψ rβ (t1) represents the fourth rotor flux component, θ r1 This represents the phase angle of the first rotor flux linkage.

8. The method for detecting residual magnetism in a motor according to claim 7, characterized in that, The determination of the second rotor flux amplitude and second rotor flux phase angle of the motor for the open-circuit maintenance time, based on the first rotor flux amplitude and the first rotor flux phase angle, includes: Substitute the first rotor flux amplitude and the first rotor flux phase angle into the preset sixth calculation formula to calculate the second rotor flux amplitude and the second rotor flux phase angle. The sixth calculation formula is: Where, ψ r2 R represents the amplitude of the second rotor flux linkage. r L represents the rotor time constant. r θ represents the rotor inductance. r2 ω represents the phase angle of the second rotor flux linkage, t1 represents the start time of the motor open circuit, t2 represents the end time of the motor open circuit, T2 represents the duration of the motor open circuit, and ω represents the phase angle of the second rotor flux linkage. m This represents the rotor angular frequency.

9. The method for detecting residual magnetism in a motor according to claim 8, characterized in that, The rotor flux at the end of the open circuit of the motor includes the fifth rotor flux component at the end of the open circuit of the motor and the sixth rotor flux component at the end of the open circuit of the motor. Determining the rotor flux linkage at the end of the motor open circuit based on the amplitude and phase angle of the second rotor flux linkage includes: Substitute the second rotor flux amplitude and the second rotor flux phase angle into the preset seventh calculation formula to determine the rotor flux at the end of the motor open circuit. The seventh calculation formula is: Where, ψ rα (t2) represents the fifth rotor flux component, ψ rβ (t2) represents the sixth rotor flux component.

10. The method for detecting residual magnetism in a motor according to claim 9, characterized in that, The stator flux linkage of the motor includes a first stator flux linkage component and a second stator flux linkage component; Based on the rotor flux linkage at the end of the open circuit of the motor, the stator flux linkage of the motor is determined, including: Substitute the rotor flux at the moment the motor ends open circuit into the preset eighth calculation formula to calculate the first stator flux component and the second stator flux component. The eighth calculation formula is: Where, ψ sα (t2) represents the first stator flux linkage component, ψ sβ (t2) represents the second stator flux linkage component, L m This represents the magnetizing inductance.

11. A method for controlling motor re-start, characterized in that, include: Based on the method for detecting residual magnetism of a motor according to any one of claims 1 to 10, the rotor flux linkage and stator flux linkage of the motor at the moment of the end of open circuit are obtained. The rotor flux linkage at the end of the open circuit of the motor and the stator flux linkage of the motor are used as the initial flux linkage to perform re-start control of the motor.

12. A device for detecting residual magnetism in a motor, characterized in that, The device includes a memory and a controller, wherein the memory stores a computer program, which, when executed by the controller, implements the method for detecting residual magnetism in a motor as described in any one of claims 1 to 10.

13. A storage medium, characterized in that, The storage medium stores a computer program, which, when executed by the controller, implements the motor flux detection method according to any one of claims 1 to 10.

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