CN110596585B

CN110596585B - Motor locked-rotor monitoring device, motor protection system and method

Info

Publication number: CN110596585B
Application number: CN201910724991.0A
Authority: CN
Inventors: 赵光焕; 王建龙; 熊毅; 厉剑波
Original assignee: Hangzhou Silan Microelectronics Co Ltd
Current assignee: Hangzhou Silan Microelectronics Co Ltd
Priority date: 2019-08-07
Filing date: 2019-08-07
Publication date: 2022-02-25
Anticipated expiration: 2039-08-07
Also published as: CN110596585A

Abstract

The motor locked-rotor monitoring device comprises a processing module, a control module and a control module, wherein the processing module is used for obtaining feedback current, estimated rotating speed and estimated angle according to the phase current of a motor; the control module is used for providing phase control voltage according to the target rotating speed, the estimated angle, the estimated rotating speed and the feedback current; and the judging module is used for judging whether the motor is locked up according to the quadrature axis voltage error value of the quadrature axis component and/or the direct axis voltage error value of the direct axis component of the phase control voltage obtained by calculation so as to provide a locked-up early warning signal. According to the motor speed estimation method and device, the estimated rotating speed and the estimated angle of the motor are obtained through the estimation of the processing module, and a position or rotating speed sensor is not needed. And whether the motor is locked-rotor is determined by a direct-axis judgment method and/or a quadrature-axis judgment method, the method can be directly applied to various sensorless permanent magnet synchronous motor control systems, the locked-rotor state of the motor is effectively detected, timely response is realized, and effective protection measures are taken to prolong the service life of the motor to the maximum extent.

Description

Motor locked-rotor monitoring device, motor protection system and method

Technical Field

The invention relates to the technical field of motor control, in particular to a motor locked-rotor monitoring device, a motor protection system and a motor locked-rotor monitoring method.

Background

With the development of motor technology, motors are widely used in various life-producing fields as core components for realizing motion. However, in practical applications, the motor has a reliability problem. The motor stalling is one of the important factors which endanger the reliability and the service life of the motor. The motor is locked due to various reasons, such as the rotor being stuck in contact with the stator, the driven device being stuck, the motor being unable to drive due to too large a load, etc.

The motor protection method is characterized in that locked-rotor detection and protection are realized on a traditional asynchronous motor, whether the motor is locked-rotor is generally judged by judging whether loop current reaches a current value needing protection, and when locked-rotor occurs, a controller turns off the motor to realize the protection function.

However, the loop current of the synchronous motor does not necessarily exceed the current threshold in the locked-rotor state, so that the above method cannot be used to identify whether the locked-rotor occurs in different motors. In the prior art, the locked rotor detection and protection functions are realized by arranging a position or rotating speed sensor. Specifically, protective measures are taken by employing position or speed sensor feedback to determine whether a motor stall has occurred. However, the use of sensor devices leads to increased system costs. Meanwhile, in many motor application occasions, sensors cannot be used, and great challenges are brought to locked rotor detection and protection.

Disclosure of Invention

In view of the above problems, an object of the present invention is to provide a motor stalling monitoring device, a motor protection system and a method thereof, so as to determine whether the motor stalls and realize the motor protection function without providing a position or rotation speed sensor.

According to an aspect of the present invention, there is provided a motor stalling monitoring device, including: the processing module is used for obtaining feedback current, estimated rotating speed and estimated angle of the motor according to phase current of the motor; a control module that provides a phase control voltage to the motor according to a target rotational speed, the estimated angle, the estimated rotational speed, and the feedback current; and the judging module is respectively connected with the processing module and the control module so as to judge whether the motor is locked according to the quadrature axis voltage error value of the quadrature axis component and/or the direct axis voltage error value of the direct axis component of the phase control voltage obtained by calculation and provide a locked rotor early warning signal according to the judgment result.

Preferably, the judging module includes: the calculating unit is used for calculating a quadrature axis voltage error value based on the motor parameter, the estimated rotating speed, the feedback current and the quadrature axis control voltage of the component of the phase control voltage on the quadrature axis; and the judging unit is used for judging whether the motor is locked up based on the quadrature axis voltage error value and providing the locked-up early warning signal.

Preferably, the judging module includes: the calculation unit is used for calculating a direct axis voltage error value based on the motor parameter, the estimated rotating speed, the feedback current and the component direct axis control voltage of the phase control voltage on the direct axis; and the judging unit is used for judging whether the motor is locked up based on the direct-axis voltage error value and providing the locked-up early warning signal.

Preferably, the judging module includes: the calculating unit is used for calculating a quadrature axis voltage error value and a direct axis voltage error value based on motor parameters, the estimated rotating speed, the feedback current, a quadrature axis control voltage component of the phase control voltage on a quadrature axis and a direct axis control voltage component of the phase control voltage on a direct axis; and the judging unit is used for judging whether the motor is locked up based on the quadrature axis voltage error value and the direct axis voltage error value and providing the locked-up early warning signal.

Preferably, the calculation unit includes: a first calculation unit for calculating a quadrature axis estimation voltage based on the motor parameter, the estimated rotation speed and the feedback current, wherein the quadrature axis estimation voltage U'_qThe calculation formula of (2) is as follows: u'_q＝R_sI_q-I_dvL_d+vK_eWherein Ld is direct-axis inductance, Iq represents quadrature-axis feedback current, Id is direct-axis feedback current, Rs is stator coil impedance, Ke is counter-electromotive force constant of the motor, and v is estimated running speed of the motor; and the second calculation unit is respectively connected with the first calculation unit and the control module and obtains a quadrature axis voltage error value based on the quadrature axis control voltage and the quadrature axis estimation voltage.

Preferably, the calculation unit includes: a first calculation unit for calculating a direct-axis estimated voltage U 'based on the motor parameter, the estimated rotation speed and the feedback current'_dThe calculation formula of (2) is as follows: u'_d＝R_sI_d-I_qvL_qWherein Lq is quadrature axis inductance, Iq represents quadrature axis feedback current, Id is direct axis feedback current, Rs is stator coil impedance, and v is estimated running speed of the motor; and the second calculation unit is respectively connected with the first calculation unit and the control module and obtains a direct-axis voltage error value based on the direct-axis control voltage and the direct-axis estimation voltage.

Preferably, the calculation unit includes: a first calculation unit for calculating a quadrature-axis estimated voltage and a direct-axis estimated voltage based on the motor parameter, the estimated rotation speed and the feedback current, wherein the quadrature-axis estimated voltage U'_qThe calculation formula of (2) is as follows: u'_q＝R_sI_q-I_dvL_d+vK_eThe direct axis estimated voltage U'_dThe calculation formula of (2) is as follows: u'_d＝R_sI_d-I_qvL_qWherein Ld is direct-axis inductance, Lq is quadrature-axis inductance, Iq represents quadrature-axis feedback current, Id is direct-axis feedback current, Rs is stator coil impedance, Ke is a counter-electromotive force constant of the motor, and v is estimated running speed of the motor; and the second calculation unit is respectively connected with the first calculation unit and the control module, and obtains a quadrature axis voltage error value based on the quadrature axis control voltage and the quadrature axis estimation voltage and obtains a direct axis voltage error value based on the direct axis control voltage and the direct axis estimation voltage.

Preferably, the quadrature axis voltage error value Err_qThe calculation formula of (2) is as follows: err_q＝U_q-U′_qWherein, U_qIs quadrature axis control voltage, U'_qThe voltage is estimated for the quadrature axis.

Preferably, the direct axis voltage error value Err_dThe calculation formula of (2) is as follows: err_d＝U_d-U′_dWherein, U_dIs direct axis control voltage, U'_dThe voltage is estimated for the direct axis.

Preferably, the judging module further comprises: and the filtering unit is used for filtering the quadrature axis voltage error value and the direct axis voltage error value and outputting the result to the judging unit.

Preferably, the judging unit includes: a first judgment unit for judging whether or not | Err is satisfied_q|>λ₁|U_qIf the quadrature axis voltage error value is within a first threshold range, the motor is locked, wherein Err_qIs the quadrature axis voltage error value, U_qFor controlling the voltage, λ, for said quadrature axis₁Is a first threshold coefficient, λ₁A positive number less than 1.

Preferably, the judging unit includes: a second judgment unit for judging whether the | Err is satisfied_d|>λ₂|U_dIf the direct-axis voltage error value is within a second threshold range, the motor is locked, wherein Err_dIs the direct axis voltage error value, U_dControlling the voltage, λ, for said direct axis₂Is a second threshold coefficient, λ₂A positive number less than 1.

Preferably, the judging unit includes: a first judgment unit for judging whether or not | Err is satisfied_q|>λ₁|U_qIf yes, determining that the quadrature axis voltage error value is within a first threshold range, wherein Err_qIs the quadrature axis voltage error value, U_qFor controlling the voltage, λ, for said quadrature axis₁Is a first threshold coefficient, λ₁Is a positive number less than 1; a second judgment unit for judging whether the | Err is satisfied_d|>λ₂|U_dIf yes, then determining that the direct-axis voltage error value is within a second threshold range, wherein Err_dIs the direct axis voltage error value, U_dControlling the voltage, λ, for said direct axis₂Is a second threshold coefficient, λ₂Is a positive number less than 1; and the logic unit is respectively connected with the first judging unit and the second judging unit, and when the quadrature axis voltage error value is within the first threshold range and the direct axis voltage error value is within the second threshold range, the motor is judged to be locked.

Preferably, the processing module comprises: the acquisition unit is used for acquiring phase current of the motor; the first conversion unit is used for converting the phase current value from a three-phase static coordinate system to a two-phase static coordinate system to obtain an intermediate phase current value and converting the intermediate phase current value from the two-phase static coordinate system to a two-phase rotating coordinate system to obtain the feedback current; and a processing unit executing a sliding mode algorithm or an extended back emf estimation algorithm to obtain the estimated rotational speed and the estimated angle based on the feedback current.

Preferably, the control module comprises: a first control unit which controls the target rotation speed and the estimated rotation speed to obtain a control current and outputs the control current; a second control unit that controls the control current and the feedback current to obtain the quadrature axis control voltage and the direct axis control voltage; and a second conversion unit which converts the phase control voltage based on the estimated angle, the quadrature axis control voltage and the direct axis control voltage to obtain the phase control voltage for controlling the motor to operate.

Preferably, the first control unit performs proportional-integral-derivative control on the target rotation speed and the estimated rotation speed to obtain the control current and outputs it.

Preferably, the second control unit performs proportional-integral-derivative control on the control current and the feedback current to obtain the quadrature axis control voltage and the direct axis control voltage.

Preferably, the motor parameters include, but are not limited to: direct axis inductance, quadrature axis inductance, stator coil impedance, and motor back emf constant.

According to another aspect of the present invention, there is provided a motor protection system including: the motor locked rotor monitoring device is described above; and the protection executing device controls the motor to be switched off when the motor is blocked by the locked-rotor early warning signal provided by the motor locked-rotor monitoring device.

Preferably, the protection execution device is connected with the motor, and when the locked-rotor early warning signal represents that the motor is locked-rotor, the protection execution device provides a control signal to turn off the motor.

Preferably, the protection execution device is connected to a control module in the protection execution device, when the stalling early warning signal represents that the motor stalls, the protection execution device controls the control module to output a corresponding phase control voltage to turn off the motor, and at least one of the phase control voltage, a target rotating speed, a quadrature axis control voltage and a direct axis control voltage is related to the stalling early warning signal.

According to another aspect of the present invention, there is provided a motor protection method including: collecting phase current of a motor; obtaining a feedback current of a motor, an estimated rotating speed and an estimated angle of the motor according to the phase current; providing a phase control voltage to the motor according to a target rotation speed, the estimated angle, the estimated rotation speed, and the feedback current; judging whether the motor is locked according to a quadrature axis voltage error value of a quadrature axis component and/or a direct axis voltage error value of a direct axis component of the phase control voltage obtained through calculation, and providing a locked-rotor early warning signal according to a judgment result; and the locked-rotor early warning signal represents that the motor is switched off when locked-rotor occurs.

Preferably, the step of determining whether the motor is locked up and providing a locked-up warning signal according to the determination result includes: calculating to obtain a quadrature axis voltage error value based on the motor parameter, the estimated rotating speed, the feedback current and the component quadrature axis control voltage of the phase control voltage on the quadrature axis; and judging whether the motor is locked up based on the quadrature axis voltage error value, and providing the locked-up early warning signal.

Preferably, the step of determining whether the motor is locked up and providing a locked-up warning signal according to the determination result includes: calculating to obtain a direct axis voltage error value based on the motor parameter, the estimated rotating speed, the feedback current and the component direct axis control voltage of the phase control voltage on the direct axis; and judging whether the motor is locked up based on the direct-axis voltage error value, and providing the locked-up early warning signal.

Preferably, the step of determining whether the motor is locked up and providing a locked-up warning signal according to the determination result includes: calculating a quadrature axis voltage error value and a direct axis voltage error value based on the motor parameters, the estimated rotating speed, the feedback current, and a component quadrature axis control voltage of the phase control voltage on a quadrature axis and a component direct axis control voltage on a direct axis; and judging whether the motor is locked up based on the quadrature axis voltage error value and the direct axis voltage error value, and providing the locked-up early warning signal.

Preferably, the step of calculating the quadrature axis voltage error value includes: calculating to obtain a quadrature axis estimation voltage based on the motor parameters, the estimated rotating speed and the feedback current, wherein the quadrature axis estimation voltage U'_qThe calculation formula of (2) is as follows: u'_q＝R_sI_q-I_dvL_d+vK_eWherein Ld is direct-axis inductance, Iq represents quadrature-axis feedback current, Id is direct-axis feedback current, Rs is stator coil impedance, Ke is counter-electromotive force constant of the motor, and v is estimated running speed of the motor; and obtaining a quadrature axis voltage error value based on the quadrature axis control voltage and the quadrature axis estimation voltage.

Preferably, the step of calculating the direct-axis voltage error value includes: calculating to obtain direct-axis estimated voltage based on the motor parameters, the estimated rotating speed and the feedback current, wherein the direct-axis estimated voltage U'_dThe calculation formula of (2) is as follows: u'_d＝R_sI_d-I_qvL_qWherein Lq is quadrature axis inductance, Iq represents quadrature axis feedback current, Id is direct axis feedback current, Rs is stator coil impedance, and v is estimated running speed of the motor; and obtaining a direct-axis voltage error value based on the direct-axis control voltage and the direct-axis estimation voltage.

Preferably, the step of calculating the quadrature axis voltage error value and the direct axis voltage error value includes: calculating to obtain quadrature axis estimated voltage and direct axis estimated voltage based on the motor parameters, the estimated rotating speed and the feedback current, wherein the quadrature axis estimated voltage U'_qThe calculation formula of (2) is as follows: u'_q＝R_sI_q-I_dvL_d+vK_eThe direct axis estimated voltage U'_dThe calculation formula of (2) is as follows: u'_d＝R_sI_d-I_qvL_qWherein Ld is direct-axis inductance, Lq is quadrature-axis inductance, Iq represents quadrature-axis feedback current, Id is direct-axis feedback current, and Rs isThe impedance of the stator coil, Ke is a counter electromotive force constant of the motor, and v is the estimated running speed of the motor; and obtaining a quadrature axis voltage error value based on the quadrature axis control voltage and the quadrature axis estimation voltage, and obtaining a direct axis voltage error value based on the direct axis control voltage and the direct axis estimation voltage.

Preferably, the step of determining whether the motor is locked up and providing a locked-up warning signal according to the determination result further includes: and filtering the quadrature axis voltage error value and the direct axis voltage error value.

Preferably, the step of determining whether the motor is locked up based on the quadrature axis voltage error value includes: when satisfying | Err_q|>λ₁|U_qIf the quadrature axis voltage error value is within a first threshold range, the motor is locked, wherein Err_qIs the quadrature axis voltage error value, U_qFor controlling the voltage, λ, for said quadrature axis₁Is a first threshold coefficient, λ₁A positive number less than 1.

Preferably, the step of determining whether the motor is locked up based on the direct-axis voltage error value includes: when satisfying | Err_d|>λ₂|U_dIf the direct-axis voltage error value is within a second threshold range, the motor is locked, wherein Err_dIs the direct axis voltage error value, U_dControlling the voltage, λ, for said direct axis₂Is a second threshold coefficient, λ₂A positive number less than 1.

Preferably, whether the motor is blocked is judged based on the quadrature axis voltage error value and the direct axis voltage error valueThe conversion step comprises: when satisfying | Err_q|>λ₁|U_qIf yes, determining that the quadrature axis voltage error value is within a first threshold range, wherein Err_qIs the quadrature axis voltage error value, U_qFor controlling the voltage, λ, for said quadrature axis₁Is a first threshold coefficient, λ₁Is a positive number less than 1; when satisfying | Err_d|>λ₂|U_dIf yes, then determining that the direct-axis voltage error value is within a second threshold range, wherein Err_dIs the direct axis voltage error value, U_dControlling the voltage, λ, for said direct axis₂Is a second threshold coefficient, λ₂Is a positive number less than 1; and when the quadrature axis voltage error value is within the first threshold range and the direct axis voltage error value is within the second threshold range, determining that the motor is locked.

Preferably, the step of obtaining the feedback current comprises: and converting the phase current value from a three-phase static coordinate system to a two-phase static coordinate system to obtain an intermediate phase current value, and converting the intermediate phase current value from the two-phase static coordinate system to a two-phase rotating coordinate system to obtain the feedback current.

Preferably, the step of obtaining the estimated rotation speed and the estimated angle comprises: executing a sliding mode algorithm or an extended back emf estimation algorithm to derive the estimated rotational speed and the estimated angle based on the feedback current.

Preferably, the step of supplying the phase control voltage to the motor according to the target rotation speed, the estimated angle, the estimated rotation speed, and the feedback current includes: controlling the target rotation speed and the estimated rotation speed to obtain a control current; controlling the control current and the feedback current to obtain the quadrature axis control voltage and the direct axis control voltage; and converting the phase control voltage based on the estimated angle, the quadrature axis control voltage and the direct axis control voltage to obtain the phase control voltage for controlling the motor to operate.

Preferably, the target rotational speed and the estimated rotational speed are subjected to proportional-integral-derivative control to obtain the control current.

Preferably, the control current and the feedback current are subjected to proportional-integral-derivative control to obtain the quadrature axis control voltage and the direct axis control voltage.

Preferably, when the locked-rotor warning signal represents that the motor is locked-rotor, a control signal is provided for the motor to turn off the motor.

Preferably, when the locked-rotor warning signal represents that the motor is locked-rotor, the corresponding phase control voltage is controlled and output to turn off the motor, and at least one of the phase control voltage, the target rotating speed, the quadrature axis control voltage and the direct axis control voltage is related to the locked-rotor warning signal.

According to the motor locked-rotor monitoring device, the motor protection system and the method thereof, the estimated rotating speed and the estimated angle of the motor operation are obtained through the estimation of the processing module, and an external position or a rotating speed sensor is not needed. And whether the motor is locked or not is determined by a direct axis judgment method and/or a quadrature axis judgment method, and the selection can be specifically carried out according to different application scenes. The invention can be directly applied to various existing sensorless permanent magnet synchronous motor control systems without adding any hardware resource, and has wide application range and low cost. The motor protection method and the motor protection device can effectively detect the locked-rotor state of the motor, have high operation speed, can realize timely response, and take effective protection measures for the motor, thereby prolonging the service life of the motor to the maximum extent.

Drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

fig. 1 shows a schematic view of a motor stall monitoring apparatus provided in accordance with the present invention;

fig. 2 is a block diagram showing a structure of a motor locked-rotor monitoring device according to a first embodiment of the present invention;

fig. 3 is a block diagram showing a motor stalling monitoring device according to a second embodiment of the invention;

fig. 4 is a block diagram showing a motor stalling monitoring device according to a third embodiment of the invention;

fig. 5 shows a schematic flow diagram of a motor protection method according to a fourth embodiment of the invention;

fig. 6 is a schematic flowchart showing a motor stall determination method performed by the motor stall monitoring apparatus according to the first embodiment of the present invention;

fig. 7 is a schematic flowchart showing a motor stall determination method performed by a motor stall monitoring apparatus according to a second embodiment of the present invention;

fig. 8 is a flowchart illustrating a motor stall determination method performed by the motor stall monitoring apparatus according to the third embodiment of the present invention.

Detailed Description

Various embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Like elements in the various figures are denoted by the same or similar reference numerals. For purposes of clarity, the various features in the drawings are not necessarily drawn to scale.

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples.

Fig. 1 shows a schematic view of a motor stall monitoring device according to an embodiment of the invention.

As shown in fig. 1, the motor locked-rotor monitoring device 100 is connected to a motor 200, and is configured to detect whether a locked-rotor occurs in the motor 200 and implement a protection measure for the motor 200.

The motor stalling monitoring device 100 includes a processing module 110, a control module 130, and a determination module 140.

The processing module 110 is connected to the motor 200, and is configured to acquire three-phase current values Ia, Ib, and Ic of the motor 200, and convert the three-phase current values into feedback currents for output, where the feedback currents include quadrature-axis feedback current Iq and direct-axis feedback current Id. And based on the quadrature feedback current Iq, the direct feedback current Id, and the motor parameters, an estimated rotation speed v and an estimated angle θ at which the motor 200 operates are calculated. The motor parameters at least comprise direct-axis inductance Ld, quadrature-axis inductance Lq, stator coil impedance Rs and motor back electromotive force constant Ke.

The control module 130 is connected to the processing module 110 to receive the estimated rotation speed v, the estimated angle θ, the quadrature axis feedback current Iq, and the direct axis feedback current Id, and the control module 130 further receives the target rotation speed vc from the outside, and obtains the quadrature axis control voltage Uq and the direct axis control voltage Ud according to the above parameters, and further obtains the phase control voltage Uc based on the quadrature axis control voltage Uq, the direct axis control voltage Ud, and the estimated angle θ to provide the phase control voltage Uc to the motor 200.

The judging module 140 is respectively connected to the processing module 110 and the control module 130, and obtains a quadrature-axis estimated voltage U 'according to the motor parameter, the estimated rotation speed v, the quadrature-axis feedback current Iq, and the direct-axis feedback current Id'_qDirect-axis estimated voltage U'_dAnd calculating a quadrature axis voltage error value of a quadrature axis component of the phase control voltage Uc and/or a direct axis voltage error value of a direct axis component of the phase control voltage Uc according to the quadrature axis control voltage Uq, the direct axis control voltage Ud and the estimated voltage to determine whether the motor 200 is locked. That is, the determining module 140 determines whether the stalling of the motor 200 occurs through a direct axis determination method and/or a quadrature axis determination method. And providing a locked rotor early warning signal according to a judgment result.

According to the motor locked-rotor monitoring device provided by the invention, the estimated rotating speed and the estimated angle of the motor operation are estimated through the processing module, and whether the motor is locked-rotor is determined through a direct axis judgment method and/or a quadrature axis judgment method, so that an external position or a rotating speed sensor is not required, and the cost can be reduced.

Fig. 2 is a block diagram showing a structure of a motor stalling monitoring device according to a first embodiment of the invention.

As shown in fig. 2, the motor stalling monitoring device 500 includes a processing module 110, a control module 130, and a determination module 240.

The processing module 110 comprises an acquisition unit 111, a first conversion unit 112 and a processing unit 113. The acquisition unit 111 is connected with the motor 200 to acquire current three-phase currents Ia, Ib and Ic of a stator in the motor 200. The first conversion unit 112 is connected to the acquisition unit 111 to receive the three-phase currents Ia, Ib, and Ic, and is configured to perform analog-to-digital conversion on the three-phase currents Ia, Ib, and Ic to obtain corresponding digital signals, and then convert the three-phase current value from the three-phase stationary coordinate system to the two-phase stationary coordinate system to obtain an intermediate two-phase current value, where the intermediate two-phase current value is converted from the two-phase stationary coordinate system to the two-phase rotating coordinate system based on at least an estimation angle θ of the motor to obtain a feedback current value, where the feedback current value includes a quadrature-axis feedback current Iq and a direct-axis feedback current Id. The first conversion unit 112 obtains and outputs the quadrature feedback current Iq and the direct feedback current Id. The processing unit 113 is connected to the first converting unit 112 to receive the quadrature feedback current Iq and the direct feedback current Id, and based on the motor parameter, the quadrature feedback current Iq and the direct feedback current Id, executes a sliding mode algorithm or an extended back emf estimation algorithm to obtain an estimated rotation speed v and an estimated angle θ of the motor. Wherein the processing unit 113 may be, for example, a software algorithm.

The control module 130 includes a first control unit 131, a second control unit 132, and a second conversion unit 133. The first control unit 131 is connected to the processing module 110 to receive the estimated rotation speed v and to receive the external target rotation speed vc, and is configured to perform proportional-integral-derivative control on the target rotation speed vc and the estimated rotation speed v to obtain the control current Ic. The second control unit 132 is respectively connected to the first control unit 131 and the first conversion unit 112 to receive the control current Ic, the quadrature feedback current Iq, and the direct feedback current Id, and is configured to perform proportional-integral-derivative control on the control current Ic, the quadrature feedback current Iq, and the direct feedback current Id to obtain the quadrature control voltage Uq and the direct control voltage Ud. The second conversion unit 133 is respectively connected to the second control unit 132 and the processing unit 113 to receive the quadrature axis control voltage Uq, the direct axis control voltage Ud and the estimated angle θ, and is used for converting the quadrature axis control voltage value into the phase control voltage Uc through the coordinate system to control the operation of the motor 200.

The judging module 240 includes a first calculating unit 241, a second calculating unit 242, and a first judging unit 243. The first calculating unit 241 is respectively connected with the processing unit 113 and the first converting unit 112 to receive the estimated rotation speed v, the quadrature feedback current Iq and the direct feedback current Id, and calculates a quadrature estimated voltage U 'based on the motor parameters'_q. Wherein the estimated voltage of the quadrature axis is according to a formula U'_q＝R_sI_q-I_dvL_d+vK_eCalculated, Ld is direct axis inductance, Iq represents quadrature axis feedback current, Id is direct axisThe shaft feedback current, Rs is the stator coil impedance, Ke is the motor back emf constant, and v is the estimated operating speed of the motor.

The second calculation unit 242 is connected to the second control unit 132 and the first calculation unit 241 to receive the quadrature control voltage Uq and the quadrature estimation voltage U'_qAnd calculating to obtain the quadrature axis voltage error value Errq. Wherein the quadrature axis voltage error value Errq is based on the formula Err_q＝U_q-U′_qCalculated, wherein Uq is quadrature axis control voltage, U'_qThe voltage is estimated for the quadrature axis.

The first determination unit 243 determines whether the motor 200 is locked based on the quadrature axis voltage error value Errq. Specifically, the first judgment unit 243 is connected to the second calculation unit 242 and passes through the formula | Err_q|>λ₁|U_qI implementation of the Cross-Axis decision method, where Err_qIs quadrature axis voltage error value, U_qFor quadrature control of voltage, λ₁Is a first threshold coefficient and is a positive number less than 1, preferably λ₁Is 0.3. When the quadrature axis voltage error value Errq satisfies the above formula, it is determined that the quadrature axis voltage error value is within the first threshold range, and it is determined that the motor 200 is locked. And outputting a locked rotor early warning signal according to the judgment result.

Preferably, a filtering unit, such as a low pass filter, is connected to the output end of the second calculating unit 242, and is used for performing filtering processing on the quadrature axis voltage error value Errq and outputting the quadrature axis voltage error value Errq.

The determining module 240 determines whether the motor is locked by using a quadrature axis determination method. When the motor is locked, the actual running rotation speed v1 of the motor becomes 0, however, the estimated rotation speed v still stays at a certain value, so that a large error exists between the obtained quadrature axis estimated voltage and the quadrature axis control voltage, and when the quadrature axis voltage error value Errq is close to 0, the motor runs normally. When the quadrature axis voltage error value Errq deviates from 0 significantly, the motor is locked.

The judging module 240 in the motor stalling monitoring device is, for example, an algorithm module, does not need to add any hardware circuit, judges whether the motor stalls by a quadrature axis judging method, and implements measures to protect the motor 200.

Fig. 3 shows a block diagram of a motor stalling monitoring device according to a second embodiment of the invention.

As shown in fig. 3, the motor stalling monitoring device 300 includes a processing module 110, a control module 130, and a determination module 340.

The determining module 340 includes a first calculating unit 341, a second calculating unit 342, and a second determining unit 344. The first calculation unit 341 is connected to the processing unit 113 and the first conversion unit 112 to receive the estimated rotation speed v, the quadrature feedback current Iq and the direct feedback current Id, and calculate the estimated direct voltage U 'based on the motor parameters'_d. Wherein the estimated voltage of the direct axis is according to a formula U'_d＝R_sI_d-I_qvL_qAnd calculating to obtain the characteristics that Ld is direct-axis inductance, Iq represents quadrature-axis feedback current, Id is direct-axis feedback current, Rs is stator coil impedance, Ke is a counter electromotive force constant of the motor, v is the estimated running rotating speed of the motor, and Lq is quadrature-axis inductance.

The second calculation unit 342 is connected to the second control unit 132 and the first calculation unit 341 to receive the direct-axis control voltage Ud, the direct-axis estimated voltage U'_dAnd is used for calculating and obtaining the direct-axis voltage error value Errd. Wherein the direct axis voltage error value Errd is based on the formula Err_d＝U_d-U′_dCalculated, where Ud is the direct axis control voltage, U'_dThe voltage is estimated for the direct axis.

The second determination unit 344 determines whether the stalling of the motor 200 occurs based on the direct-axis voltage error value Errd. Specifically, the second judgment unit 344 is connected to the second calculation unit 342 and passes the formula | Err_d|>λ₂|U_dI implementation of the straight-axis decision method, where Err_dIs the direct axis voltage error value, U_dFor control of the voltage, λ, for the direct axis₂Is a second threshold coefficient and is a positive number less than 1, preferably λ₂Is 0.3. When the direct-axis voltage error value Errd satisfies the above formula, it is determined that the direct-axis voltage error value is within the second threshold range, and it is determined that the motor 200 is locked. And outputting a locked rotor early warning signal according to the judgment result.

Preferably, a filtering unit, such as a low pass filter, is connected to the output end of the second calculating unit 342 and is used for filtering and outputting the direct-axis voltage error value Errd, and the filtering unit is used for reducing the influence of the control noise on the direct-axis voltage error value Errd.

The determination module 340 determines whether the motor is locked by using a direct axis determination method. When the motor is locked, the actual running rotation speed v1 of the motor becomes 0, however, the estimated rotation speed v still stays at a certain value, so that a large error exists between the obtained estimated voltage of the direct axis and the control voltage of the direct axis, and when the error value Errd of the voltage of the direct axis is close to 0, the motor runs normally. When the direct-axis voltage error value Errd deviates from 0, the motor is locked.

The judging module in the motor locked-rotor monitoring device is an algorithm module, for example, no hardware circuit is required to be added, whether the motor is locked-rotor is judged by a direct-axis judging method, and measures are implemented to protect the motor 200.

Fig. 4 is a block diagram showing a motor stalling monitoring device according to a third embodiment of the invention.

As shown in fig. 4, the motor stalling monitoring device 400 includes a processing module 110, a control module 130, and a determination module 440.

The determining module 440 includes a first calculating unit 441, a second calculating unit 442, a first determining unit 443, a second determining unit 444, and a logic unit 445. The first calculating unit 441 is respectively connected with the processing unit 113 and the first converting unit 112 to receive the estimated rotation speed v, the quadrature-axis feedback current Iq and the direct-axis feedback current Id, and calculate the quadrature-axis estimated voltage U 'based on the motor parameters'_qDirect-axis estimated voltage U'_d. Wherein the estimated voltage of the quadrature axis is according to a formula U'_q＝R_sI_q-I_dvL_d+vK_eAnd calculating to obtain the inductance of the direct axis, the quadrature axis feedback current of Iq, the direct axis feedback current of Id, the stator coil impedance of Rs, the counter electromotive force constant of the motor of Ke and the estimated running speed of the motor of v. The direct-axis estimated voltage is according to a formula U'_d＝R_sI_d-I_qvL_qAnd Lq is calculated and is the quadrature axis inductance.

The second calculating units 442 are respectively connected with the second control unitsElement 132 and first calculation unit 441 are configured to receive quadrature control voltage Uq, direct control voltage Ud, quadrature estimation voltage U'_qDirect-axis estimated voltage U'_dAnd the error value is used for calculating and obtaining a quadrature axis voltage error value Errq and a direct axis voltage error value Errd. Wherein the direct axis voltage error value Errd is based on the formula Err_d＝U_d-U′_dCalculated, where Ud is the direct axis control voltage, U'_dThe voltage is estimated for the direct axis. Quadrature axis voltage error value Errq according to the formula Err_q＝U_q-U′_qCalculated, wherein Uq is quadrature axis control voltage, U'_qThe voltage is estimated for the quadrature axis.

The first determining unit 443, the second determining unit 444, and the logic unit 445 determine whether the motor 200 is locked based on the quadrature axis voltage error value Errq and the direct axis voltage error value Errd. Specifically, the first determination unit 443 is connected to the second calculation unit 442 and uses the formula | Err_q|>λ₁|U_qI implementation of the Cross-Axis decision method, where Err_qIs quadrature axis voltage error value, U_qFor quadrature control of voltage, λ₁Is a first threshold coefficient and is a positive number less than 1, preferably λ₁Is 0.3. When the quadrature axis voltage error value Errq satisfies the above formula, it is determined that the quadrature axis voltage error value is within the first threshold range. The second judgment unit 444 is connected to the second calculation unit 442 and passes the formula | Err_d|>λ₂|U_dI implementation of the straight-axis decision method, where Err_dIs the direct axis voltage error value, U_dFor control of the voltage, λ, for the direct axis₂Is a second threshold coefficient and is a positive number less than 1, preferably λ₂Is 0.3. When the direct-axis voltage error value Errd satisfies the above formula, it is determined that the direct-axis voltage error value is within the second threshold range. The logic unit 145 is connected to the first determining unit 443 and the second determining unit 444 respectively, and when the quadrature axis voltage error value is within a first threshold range and the direct axis voltage error value is within a second threshold range, it is determined that the motor 200 is locked, wherein the determining logic of the logic unit 145 is specifically set according to the actual application situation. In this embodiment, the judgment logic of the logic unit 145 is configured to combine the direct axis judgment method and the quadrature axis judgment method to judgeWhether the motor is locked. Lambda [ alpha ]₁And λ₂Can be arranged independently of one another or can be matched to one another. And outputting a locked rotor early warning signal according to the judgment result.

Preferably, a filtering unit is connected to an output end of the second calculating unit 442, and is configured to perform filtering processing on the quadrature axis voltage error value Errq and the direct axis voltage error value Errd and output the processed results, where the filtering unit is, for example, a low-pass filter, and is configured to reduce an influence of control noise on the quadrature axis voltage error value Errq and the direct axis voltage error value Errd.

The determining module 440 determines whether the locked rotor of the motor occurs by using a direct axis determination method and a quadrature axis determination method. When the motor is locked, the actual running rotation speed v1 of the motor becomes 0, however, the estimated rotation speed v still stays at a certain value, so that the obtained quadrature-direct axis estimated voltage and the quadrature-direct axis control voltage have a large error, and when the quadrature-axis voltage error value Errq and the direct-axis voltage error value Errd are close to 0, the motor normally runs. When the quadrature axis voltage error value Errq and the direct axis voltage error value Errd deviate from 0, the motor is locked.

The judging module in the motor locked-rotor monitoring device is an algorithm module, for example, no hardware circuit is required to be added, whether the motor is locked-rotor is judged by a direct-axis and quadrature-axis judging method, and the motor 200 is protected by implementing measures.

The invention also provides a motor protection system which comprises the motor locked-rotor monitoring device and the protection executing device, wherein when the locked-rotor early warning signal represents that the motor is locked-rotor, the protection executing device turns off the motor. Specifically, the protection execution device can be directly connected with the motor, and when the locked-rotor early warning signal represents that the motor is locked-rotor, the protection execution device directly provides a control signal for the motor to shut down the motor. Optionally, the protection executing device is connected to the control module, and when the locked-rotor warning signal indicates that the motor is locked, the protection executing device controls the control module to output a corresponding phase control voltage to turn off the motor, where at least one of the phase control voltage Uc, the target rotation speed vc, the quadrature axis control voltage Uq, and the direct axis control voltage Ud is related to the locked-rotor warning signal.

Fig. 5 shows a schematic flow chart of a motor protection method according to a fourth embodiment of the invention.

As shown in fig. 5, the motor protection method includes the following steps:

step S10: the phase current of the motor is collected, and the collection unit 111 of the processing module 110 collects the phase currents Ia, Ib and Ic of the motor.

Step S20: and obtaining the feedback current, the estimated rotating speed and the estimated angle of the motor according to the phase current. The first conversion unit 112 of the processing module 110 converts the acquired three-phase current of the motor to obtain a feedback current, where the feedback current includes a quadrature feedback current Iq and a direct feedback current Id, and the processing unit 113 executes a sliding mode algorithm or an extended back emf estimation algorithm to obtain an estimated rotation speed v and an estimated angle θ based on the quadrature feedback current Iq and the direct feedback current Id.

Step S30: and providing phase control voltage for the motor according to the target rotating speed, the estimated rotating speed and the feedback current. The control module 130 obtains quadrature axis control voltage and direct axis control voltage according to the feedback current, the estimated rotation speed and the target rotation speed, and obtains phase control voltage for controlling the motor to operate based on the quadrature axis control voltage, the direct axis control voltage and the estimated angle.

Step S40: and judging whether the motor is locked according to the quadrature axis voltage error value and/or the direct axis voltage error value obtained by calculation. The judging module 140 calculates a quadrature axis estimated voltage and a direct axis estimated voltage based on the motor parameters, the estimated rotation speed and the feedback current, calculates a quadrature axis voltage error value and/or a direct axis voltage error value according to a component quadrature axis control voltage of the phase control voltage on the quadrature axis and a component direct axis control voltage on the direct axis, judges whether the motor is locked by executing a direct axis judging method and/or a quadrature axis judging method, and provides a corresponding locked-rotor early warning signal according to a judging result.

Step S50: and (5) motor locked-rotor protection. The protection execution device is connected to the judgment module 140 to receive the locked rotor early warning signal, and when the locked rotor early warning signal indicates that the motor is locked rotor, the protection execution device controls to turn off the motor. Specifically, the protection execution device can be directly connected with the motor, and when the locked-rotor early warning signal represents that the motor is locked-rotor, the protection execution device directly provides a control signal for the motor to shut down the motor. Optionally, the protection executing device may be connected to the control module, and when the locked rotor warning signal indicates that the motor is locked rotor, the protection executing device controls the control module to output a corresponding phase control voltage to turn off the motor, where at least one of the phase control voltage Uc, the target rotation speed vc, the quadrature axis control voltage Uq, and the direct axis control voltage Ud is related to the locked rotor warning signal.

Fig. 6 is a flowchart illustrating a motor stall determination method performed by the motor stall monitoring apparatus according to the first embodiment of the present invention.

When the motor protection method provided by the present invention is implemented in the motor locked-rotor monitoring device of the first embodiment, the motor locked-rotor determining method includes the following steps:

step S411: and starting locked rotor judgment. And executing a quadrature axis judgment method after the locked rotor judgment is started.

Step S412: and calculating a quadrature axis voltage error value. The first calculating unit of the determining module 140 calculates the quadrature axis estimated voltage based on the motor parameter, the feedback current, and the estimated rotation speed, and calculates the quadrature axis voltage error value according to the quadrature axis estimated voltage and the quadrature axis control voltage of the phase control voltage on the quadrature axis through the second calculating unit.

Step S413: and filtering the quadrature axis voltage error value. The determining module 140 performs filtering processing on the quadrature axis voltage error value by setting a filtering unit, so as to reduce the influence of control noise.

Step S414: and judging whether the quadrature axis voltage error value is within a first threshold range. The first judging unit 143 of the judging module 140 is connected to the second calculating unit 142 and uses the formula | Err_q|>λ₁|U_qI implementation of the Cross-Axis decision method, where Err_qIs quadrature axis voltage error value, U_qFor quadrature control of voltage, λ₁Is a first threshold coefficient and is a positive number less than 1, preferably λ₁Is 0.3. And restarting the locked-rotor judgment when the quadrature axis voltage error value Errq does not meet the formula.

When the quadrature axis voltage error value Errq satisfies the above formula, it is determined that the quadrature axis voltage error value is within the first threshold range, and it is determined that the motor is locked, and then step S50 is executed: and (4) motor locked-rotor protection, wherein when the locked-rotor early warning signal represents that the motor is locked-rotor, the protection execution device controls to turn off the motor.

Fig. 7 is a flowchart illustrating a motor stall determination method performed by the motor stall monitoring apparatus according to the second embodiment of the present invention.

When the motor protection method provided by the present invention is implemented in the motor locked-rotor monitoring device of the second embodiment, the motor locked-rotor determining method includes the following steps:

step S421: and starting locked rotor judgment. And executing a straight shaft judgment method after the locked rotor judgment is started.

Step S422: a direct axis voltage error value is calculated. The first calculating unit of the determining module 140 calculates the estimated direct-axis voltage based on the motor parameter, the feedback current, and the estimated rotation speed, and calculates the direct-axis voltage error value according to the estimated direct-axis voltage and the component direct-axis control voltage of the phase control voltage on the direct axis through the second calculating unit.

Step S423: and filtering the direct axis voltage error value. The determining module 140 performs filtering processing on the direct-axis voltage error value by setting a filtering unit, so as to reduce the influence of control noise.

Step S424: and judging whether the direct-axis voltage error value is within a second threshold range. The second judging unit 144 of the judging module 140 is connected to the second calculating unit 142 and uses the formula | Err_d|>λ₂|U_dI implementation of the straight-axis decision method, where Err_dIs the direct axis voltage error value, U_dFor control of the voltage, λ, for the direct axis₂Is a second threshold coefficient and is a positive number less than 1, preferably λ₁Is 0.3. And restarting the locked-rotor judgment when the direct-axis voltage error value Errd does not meet the formula.

When the direct-axis voltage error value Errd satisfies the above formula, it is determined that the direct-axis voltage error value is within the second threshold range, and it is determined that the motor is locked, and then step S50 is executed: and (4) motor locked-rotor protection, wherein when the locked-rotor early warning signal represents that the motor is locked-rotor, the protection execution device controls to turn off the motor.

When the motor protection method provided by the present invention is implemented in the motor locked-rotor monitoring device according to the third embodiment, the motor locked-rotor determining method includes the following steps: step S431: and starting locked rotor judgment. And respectively executing the straight axis judgment and the quadrature axis judgment after the locked rotor judgment is started.

Specifically, the quadrature axis judging step is as follows:

step S432: and calculating a quadrature axis voltage error value. The first calculating unit of the determining module 140 calculates the quadrature axis estimated voltage based on the motor parameter, the feedback current, and the estimated rotation speed, and calculates the quadrature axis voltage error value according to the quadrature axis estimated voltage and the quadrature axis control voltage of the phase control voltage on the quadrature axis through the second calculating unit.

Step S433: and filtering the quadrature axis voltage error value. The determining module 140 performs filtering processing on the quadrature axis voltage error value by setting a filtering unit, so as to reduce the influence of control noise.

Step S434: and judging whether the quadrature axis voltage error value is within a first threshold range. The first judging unit 143 of the judging module 140 is connected to the second calculating unit 142 and uses the formula | Err_q|>λ₁|U_qI implementation of the Cross-Axis decision method, where Err_qIs quadrature axis voltage error value, U_qFor quadrature control of voltage, λ₁Is a first threshold coefficient and is a positive number less than 1, preferably λ₁Is 0.3. When the quadrature axis voltage error value Errq satisfies the above formula, it is determined that the quadrature axis voltage error value is within the first threshold range. And restarting the quadrature axis judgment when the quadrature axis voltage error value Errq does not satisfy the formula.

Specifically, the straight axis judging step is as follows:

step S435: a direct axis voltage error value is calculated. The first calculating unit of the determining module 140 calculates the estimated direct-axis voltage based on the motor parameter, the feedback current, and the estimated rotation speed, and calculates a direct-axis voltage error value according to the estimated direct-axis voltage and the component direct-axis control voltage of the phase control voltage on the direct axis through the second calculating unit.

Step S436: and filtering the direct axis voltage error value. The determining module 140 performs filtering processing on the direct-axis voltage error value by setting a filtering unit, so as to reduce the influence of control noise.

Step S437: and judging whether the direct-axis voltage error value is within a second threshold range. The second judging unit 144 of the judging module 140 passes the formula | Err_d|>λ₂|U_dI implementation of the straight-axis decision method, where Err_dIs the direct axis voltage error value, U_dFor control of the voltage, λ, for the direct axis₂Is a second threshold coefficient and is less than a positive number of 1, preferably λ₂Is 0.3. When the direct-axis voltage error value Errd satisfies the above formula, it is determined that the direct-axis voltage error value is within the second threshold range. And restarting the direct axis judgment when the direct axis voltage error value Errd does not meet the formula.

When the quadrature axis voltage error value is within the first threshold range and the direct axis voltage error value is within the second threshold range, it is determined that the motor is locked, and then step S50 is executed: and (5) motor locked-rotor protection. When the motor is judged to be locked, the locked-rotor early warning signal is characterized in that the motor is locked, and the protection execution device is controlled to switch off the motor. In the motor locked-rotor judging method, the quadrature axis locked-rotor judging operation and the direct axis locked-rotor judging operation may be performed simultaneously or sequentially.

While embodiments in accordance with the invention have been described above, these embodiments are not intended to be exhaustive or to limit the invention to the precise embodiments described. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. The utility model provides a motor locked rotor monitoring devices which characterized in that includes:

the processing module is used for obtaining feedback current, estimated rotating speed and estimated angle of the motor according to phase current of the motor;

a control module that provides a phase control voltage to the motor according to a target rotational speed, the estimated angle, the estimated rotational speed, and the feedback current; and

the judging module is respectively connected with the processing module and the control module, judges whether the motor is locked up, and provides a locked up early warning signal according to a judging result, wherein the judging module comprises:

the calculating unit is used for calculating a quadrature axis voltage error value and/or a direct axis voltage error value based on motor parameters, the estimated rotating speed, the feedback current, a quadrature axis control voltage component of the phase control voltage on a quadrature axis and a direct axis control voltage component of the phase control voltage on a direct axis; and

and the judging unit is used for judging whether the motor is locked up based on the quadrature axis voltage error value and/or the direct axis voltage error value and providing the locked-up early warning signal.

2. The device of claim 1, wherein the determining module comprises:

the calculating unit is used for calculating a quadrature axis voltage error value based on the motor parameter, the estimated rotating speed, the feedback current and the quadrature axis control voltage of the component of the phase control voltage on the quadrature axis; and

and the judging unit judges whether the motor is locked up based on the quadrature axis voltage error value and provides the locked-up early warning signal.

3. The device of claim 1, wherein the determining module comprises:

the calculation unit is used for calculating a direct axis voltage error value based on the motor parameter, the estimated rotating speed, the feedback current and the component direct axis control voltage of the phase control voltage on the direct axis; and

and the judging unit judges whether the motor is locked up based on the direct-axis voltage error value and provides the locked-up early warning signal.

4. The motor stall monitoring device of claim 2, wherein the computing unit comprises:

a first calculation unit for calculating a quadrature axis estimation voltage based on the motor parameter, the estimated rotation speed and the feedback current, wherein the quadrature axis estimation voltage U'_qThe calculation formula of (2) is as follows:

U′_q＝R_sI_q-I_dvL_d+vK_e

wherein Ld is direct-axis inductance, Iq represents quadrature-axis feedback current, Id is direct-axis feedback current, Rs is stator coil impedance, Ke is counter-electromotive force constant of the motor, and v is estimated running speed of the motor; and

and the second calculation unit is respectively connected with the first calculation unit and the control module and obtains a quadrature axis voltage error value based on the quadrature axis control voltage and the quadrature axis estimation voltage.

5. The motor stall monitoring device of claim 3, wherein the computing unit comprises:

a first calculation unit for calculating a direct-axis estimated voltage U 'based on the motor parameter, the estimated rotation speed and the feedback current'_dThe calculation formula of (2) is as follows:

U′_d＝R_sI_d-I_qvL_q

wherein Lq is quadrature axis inductance, Iq represents quadrature axis feedback current, Id is direct axis feedback current, Rs is stator coil impedance, and v is estimated running speed of the motor; and

and the second calculation unit is respectively connected with the first calculation unit and the control module and obtains a direct-axis voltage error value based on the direct-axis control voltage and the direct-axis estimation voltage.

6. The motor stall monitoring device of claim 1, wherein the computing unit comprises:

a first calculation unit for calculating a quadrature-axis estimated voltage and a direct-axis estimated voltage based on the motor parameter, the estimated rotation speed and the feedback current, wherein the quadrature-axis estimated voltage U'_qThe calculation formula of (2) is as follows: u'_q＝R_sI_q-I_dvL_d+vK_eThe direct axis estimated voltage U'_dThe calculation formula of (2) is as follows: u'_d＝R_sI_d-I_qvL_qWherein Ld is direct-axis inductance, Lq is quadrature-axis inductance, Iq represents quadrature-axis feedback current, Id is direct-axis feedback current, Rs is stator coil impedance, Ke is a counter-electromotive force constant of the motor, and v is estimated running speed of the motor; and

and the second calculation unit is respectively connected with the first calculation unit and the control module, and obtains a quadrature axis voltage error value based on the quadrature axis control voltage and the quadrature axis estimation voltage and obtains a direct axis voltage error value based on the direct axis control voltage and the direct axis estimation voltage.

7. The motor stall monitoring device of claim 4 or 6, wherein the quadrature axis voltage error value Err_qThe calculation formula of (2) is as follows:

Err_q＝U_q-U′_q

wherein, U_qIs quadrature axis control voltage, U'_qThe voltage is estimated for the quadrature axis.

8. The motor stall monitoring device of claim 5 or 6, wherein the direct axis voltage error value Err_dThe calculation formula of (2) is as follows:

Err_d＝U_d-U′_d

wherein, U_dIs direct axis control voltage, U'_dThe voltage is estimated for the direct axis.

9. The device according to any one of claims 1 to 3, wherein the determining module further comprises:

and the filtering unit is used for filtering the quadrature axis voltage error value and the direct axis voltage error value and outputting the result to the judging unit.

10. The motor stalling monitoring device according to claim 2, wherein the determining unit comprises:

a first judgment unit for judging whether or not | Err is satisfied_q|＞λ₁|U_qIf the quadrature axis voltage error value is within a first threshold range, the motor is locked, wherein Err_qIs the quadrature axis voltage error value, U_qFor controlling the voltage, λ, for said quadrature axis₁Is a first threshold coefficient, λ₁A positive number less than 1.

11. The motor stalling monitoring device according to claim 3, wherein the determining unit comprises:

a second judgment unit for judging whether the | Err is satisfied_d|＞λ₂|U_dIf the direct-axis voltage error value is within a second threshold range, the motor is locked, wherein Err_dIs the direct axis voltage error value, U_dControlling the voltage, λ, for said direct axis₂Is a second threshold coefficient, λ₂A positive number less than 1.

12. The motor stalling monitoring device according to claim 1, wherein the determining unit comprises:

a first judgment unit for judging whether or not | Err is satisfied_q|＞λ₁|U_qIf yes, determining that the quadrature axis voltage error value is within a first threshold range, wherein Err_qIs the quadrature axis voltage error value, U_qFor controlling the voltage, λ, for said quadrature axis₁Is a first threshold coefficient, λ₁Is a positive number less than 1;

a second judgment unit for judging whether the | Err is satisfied_d|＞λ₂|U_d|，Determining that the direct-axis voltage error value is within a second threshold range, where Err_dIs the direct axis voltage error value, U_dControlling the voltage, λ, for said direct axis₂Is a second threshold coefficient, λ₂Is a positive number less than 1; and

and the logic unit is respectively connected with the first judging unit and the second judging unit, and when the quadrature axis voltage error value is within the first threshold range and the direct axis voltage error value is within the second threshold range, the motor is judged to be locked.

13. The motor stall monitoring device of claim 1, wherein the processing module comprises:

the acquisition unit is used for acquiring phase current of the motor;

the first conversion unit is used for converting the phase current value from a three-phase static coordinate system to a two-phase static coordinate system to obtain an intermediate phase current value and converting the intermediate phase current value from the two-phase static coordinate system to a two-phase rotating coordinate system to obtain the feedback current; and

and the processing unit executes a sliding mode algorithm or an expanded back emf estimation algorithm to obtain the estimated rotating speed and the estimated angle based on the feedback current.

14. The motor stall monitoring device of claim 1, wherein the control module comprises:

a first control unit which controls the target rotation speed and the estimated rotation speed to obtain a control current and outputs the control current;

a second control unit that controls the control current and the feedback current to obtain the quadrature axis control voltage and the direct axis control voltage; and

and the second conversion unit is used for converting the phase control voltage based on the estimated angle, the quadrature axis control voltage and the direct axis control voltage to obtain the phase control voltage and controlling the motor to operate.

15. The motor stalling monitoring device according to claim 14, wherein the first control unit performs proportional-integral-derivative control on the target rotational speed and the estimated rotational speed to obtain the control current and outputs the control current.

16. The motor stall monitoring device of claim 14, wherein the second control unit performs proportional-integral-derivative control on the control current and the feedback current to obtain the quadrature axis control voltage and the direct axis control voltage.

17. The motor stall monitoring device of any of claims 1-3, wherein the motor parameters include, but are not limited to: direct axis inductance, quadrature axis inductance, stator coil impedance, and motor back emf constant.

18. A motor protection system, comprising:

the motor stall monitoring device of any one of claims 1-17; and

and the protection executing device controls and shuts off the motor when the motor is blocked by the locked-rotor early warning signal provided by the motor locked-rotor monitoring device.

19. The motor protection system according to claim 18, wherein the protection executing device is connected to the motor, and when the stalling early warning signal indicates that the motor stalls, the protection executing device provides a control signal to shut down the motor.

20. The motor protection system according to claim 18, wherein the protection execution device is connected to a control module in the protection execution device, and when the stall warning signal indicates that the motor stalls, the protection execution device controls the control module to output a corresponding phase control voltage to shut down the motor, wherein at least one of the phase control voltage, the target rotation speed, the quadrature axis control voltage, and the direct axis control voltage is related to the stall warning signal.

21. A method of protecting a motor, comprising:

collecting phase current of a motor;

obtaining a feedback current of a motor, an estimated rotating speed and an estimated angle of the motor according to the phase current;

providing a phase control voltage to the motor according to a target rotation speed, the estimated angle, the estimated rotation speed, and the feedback current;

judging whether the motor is locked up and providing a locked-up early warning signal according to a judgment result; and

the locked-rotor early warning signal represents that the motor is switched off when the motor is locked,

wherein, judge whether the motor stalls and provide the step of stalling early warning signal according to the judged result and include:

calculating a quadrature axis voltage error value and/or a direct axis voltage error value based on the motor parameters, the estimated rotating speed, the feedback current, and a component quadrature axis control voltage of the phase control voltage on a quadrature axis and a component direct axis control voltage on a direct axis; and

and judging whether the motor is locked or not based on the quadrature axis voltage error value and/or the direct axis voltage error value, and providing the locked-rotor early warning signal.

22. The motor protection method of claim 21, wherein the step of determining whether the motor is locked and providing a lock warning signal according to the determination result comprises:

calculating to obtain a quadrature axis voltage error value based on the motor parameter, the estimated rotating speed, the feedback current and the component quadrature axis control voltage of the phase control voltage on the quadrature axis; and

and judging whether the motor is locked up based on the quadrature axis voltage error value, and providing the locked-up early warning signal.

23. The motor protection method of claim 21, wherein the step of determining whether the motor is locked and providing a lock warning signal according to the determination result comprises:

calculating to obtain a direct axis voltage error value based on the motor parameter, the estimated rotating speed, the feedback current and the component direct axis control voltage of the phase control voltage on the direct axis; and

and judging whether the motor is locked up based on the direct-axis voltage error value, and providing the locked-up early warning signal.

24. The motor protection method of claim 22, wherein calculating the quadrature voltage error value comprises:

calculating to obtain a quadrature axis estimation voltage based on the motor parameters, the estimated rotating speed and the feedback current, wherein the quadrature axis estimation voltage U'_qThe calculation formula of (2) is as follows:

U′_q＝R_sI_q-I_dvL_d+vK_e

and obtaining a quadrature axis voltage error value based on the quadrature axis control voltage and the quadrature axis estimation voltage.

25. The motor protection method of claim 21, wherein calculating the direct-axis voltage error value comprises:

calculating to obtain direct-axis estimated voltage based on the motor parameters, the estimated rotating speed and the feedback current, wherein the direct-axis estimated voltage U'_dThe calculation formula of (2) is as follows:

U′_d＝R_sI_d-I_qvL_q

and obtaining a direct-axis voltage error value based on the direct-axis control voltage and the direct-axis estimation voltage.

26. The motor protection method of claim 21, wherein the step of calculating the quadrature axis voltage error value and/or the direct axis voltage error value comprises:

calculating to obtain quadrature axis estimated voltage and direct axis estimated voltage based on the motor parameters, the estimated rotating speed and the feedback current, wherein the quadrature axis estimated voltage U'_qThe calculation formula of (2) is as follows: u'_q＝R_sI_q-I_dvL_d+vK_eThe direct axis estimated voltage U'_dThe calculation formula of (2) is as follows: u'_d＝R_sI_d-I_qvL_qWherein Ld is direct-axis inductance, Lq is quadrature-axis inductance, Iq represents quadrature-axis feedback current, Id is direct-axis feedback current, Rs is stator coil impedance, Ke is a counter-electromotive force constant of the motor, and v is estimated running speed of the motor; and/or

And obtaining a quadrature axis voltage error value based on the quadrature axis control voltage and the quadrature axis estimation voltage, and obtaining a direct axis voltage error value based on the direct axis control voltage and the direct axis estimation voltage.

27. The method of claim 24 or 25 wherein the quadrature axis voltage error value Err is_qThe calculation formula of (2) is as follows:

Err_q＝U_q-U′_q

28. The method of protecting a motor of claim 25 or 26 wherein the direct axis voltage error value Err is_dThe calculation formula of (2) is as follows:

Err_d＝U_d-U′_d

29. The motor protection method according to any one of claims 21 to 23, wherein the step of determining whether the motor is locked up and providing a lock-up warning signal according to the determination result further comprises:

and filtering the quadrature axis voltage error value and the direct axis voltage error value.

30. The motor protection method of claim 21, wherein determining whether the motor is stalled based on the quadrature voltage error value comprises:

when satisfying | Err_q|＞λ₁|U_qIf the quadrature axis voltage error value is within a first threshold range, the motor is locked, wherein Err_qIs the quadrature axis voltage error value, U_qFor controlling the voltage, λ, for said quadrature axis₁Is a first threshold coefficient, λ₁A positive number less than 1.

31. The motor protection method of claim 21, wherein determining whether the motor is stalled based on the direct-axis voltage error value comprises:

when satisfying | Err_d|＞λ₂|U_dIf the direct-axis voltage error value is within a second threshold range, the motor is locked, wherein Err_dIs the direct axis voltage error value, U_dControlling the voltage, λ, for said direct axis₂Is a second threshold coefficient, λ₂A positive number less than 1.

32. The motor protection method of claim 23, wherein determining whether the motor is stalled based on the quadrature axis voltage error value and/or the direct axis voltage error value comprises:

when satisfying | Err_q|＞λ₁|U_qIf yes, determining the quadrature axis voltage error valueWithin a first threshold range, where Err_qIs the quadrature axis voltage error value, U_qFor controlling the voltage, λ, for said quadrature axis₁Is a first threshold coefficient, λ₁Is a positive number less than 1;

when satisfying | Err_d|＞λ₂|U_dIf yes, then determining that the direct-axis voltage error value is within a second threshold range, wherein Err_dIs the direct axis voltage error value, U_dControlling the voltage, λ, for said direct axis₂Is a second threshold coefficient, λ₂Is a positive number less than 1; and

and when the quadrature axis voltage error value is within the first threshold range and/or the direct axis voltage error value is within the second threshold range, determining that the motor is locked.

33. The motor protection method of claim 21, wherein the step of obtaining the feedback current comprises:

and converting the phase current value from a three-phase static coordinate system to a two-phase static coordinate system to obtain an intermediate phase current value, and converting the intermediate phase current value from the two-phase static coordinate system to a two-phase rotating coordinate system to obtain the feedback current.

34. The motor protection method of claim 33, wherein the step of obtaining the estimated rotational speed and the estimated angle comprises:

executing a sliding mode algorithm or an extended back emf estimation algorithm to derive the estimated rotational speed and the estimated angle based on the feedback current.

35. The motor protection method of claim 21, wherein the step of providing a phase control voltage to the motor based on a target speed, the estimated angle, the estimated speed, and the feedback current comprises:

controlling the target rotation speed and the estimated rotation speed to obtain a control current;

controlling the control current and the feedback current to obtain the quadrature axis control voltage and the direct axis control voltage; and

and converting the phase control voltage based on the estimated angle, the quadrature axis control voltage and the direct axis control voltage to obtain the phase control voltage for controlling the motor to operate.

36. The motor protection method according to claim 35, wherein the target rotation speed and the estimated rotation speed are subjected to proportional-integral-derivative control to obtain the control current.

37. The motor protection method of claim 35, wherein the control current and the feedback current are subjected to proportional-integral-derivative control to obtain the quadrature-axis control voltage and the direct-axis control voltage.

38. The method of claim 21, wherein when the stall warning signal indicates that the motor stalls, a control signal is provided to the motor to shut down the motor.

39. The motor protection method according to claim 21, wherein when the stall warning signal indicates that the motor stalls, a corresponding phase control voltage is controlled to be output to shut down the motor, and at least one of the phase control voltage, the target rotation speed, the quadrature axis control voltage and the direct axis control voltage is related to the stall warning signal.