Motor demagnetization detection and processing method, controller, system, automobile and storage medium

Abstract

The present invention discloses a motor demagnetization detection processing method, a controller, a system, a vehicle and a storage medium. The method comprises: obtaining measured motor data, wherein the measured motor data comprises first motor data and second motor data; determining a first phase current deviation rate based on the first motor data and the second motor data; performing demagnetization detection based on the first phase current deviation rate, and determining the demagnetization detection result. This solution can effectively reduce the cost of motor demagnetization detection and reduce the operational complexity of demagnetization detection.

Description

Technical Field

[0001] The present invention relates to the technical field of motor demagnetization detection and processing, and in particular to a motor demagnetization detection and processing method, a controller, a system, a vehicle and a storage medium. Background Art

[0002] Motor demagnetization refers to the phenomenon that the magnetic field strength in the motor weakens or disappears, which usually causes the motor to malfunction, reduce efficiency, increase energy consumption, and increase noise and vibration until the motor fails completely.

[0003] Existing motor demagnetization detection generally includes the following two methods: The first method is mainly to perform demagnetization detection by identifying magnetic flux information. Specifically, a voltage sensor or a voltage detection circuit is required to detect the back electromotive force of the motor, and then the magnetic flux amplitude calculated by the back electromotive force is compared with the magnetic flux threshold to determine whether the motor demagnetization phenomenon exists. The second method is mainly to perform demagnetization detection by calculating the power deviation. Specifically, the requested power is determined according to the requested speed and requested torque; the measured power is determined according to the actual detected motor current and motor voltage, and then the deviation between the requested power and the measured power is used to determine whether the motor demagnetization phenomenon exists. This solution also requires the use of a voltage sensor or a voltage detection circuit to detect the motor voltage.

[0004] In summary, the existing motor demagnetization detection process generally requires the use of a voltage sensor or a voltage detection circuit for voltage detection, which results in a high cost for motor demagnetization detection. Summary of the invention

[0005] Embodiments of the present invention provide a motor demagnetization detection processing method, a controller, a system, a vehicle and a storage medium to solve the problem of high cost in the existing motor demagnetization detection processing process.

[0006] A motor demagnetization detection and processing method, comprising:

[0007] Acquire measured motor data, wherein the measured motor data includes first motor data and second motor data;

[0008] Determine a first phase current deviation rate based on the first motor data and the second motor data;

[0009] Demagnetization detection is performed based on the first phase current deviation rate to determine the demagnetization detection result.

[0010] Preferably, determining the first phase current deviation rate based on the first motor data and the second motor data includes:

[0011] Determine the measured phase current effective value based on the first motor data;

[0012] Determine a reference phase current effective value based on the second motor data;

[0013] A first phase current deviation rate is determined based on the measured phase current effective value and the reference phase current effective value.

[0014] Preferably, the first motor data includes motor current;

[0015] The step of determining the measured phase current effective value based on the first motor data includes:

[0016] Based on all the motor currents within a preset period, the measured phase current effective value is determined.

[0017] Preferably, determining the reference phase current effective value based on the second motor data includes:

[0018] Based on the second motor data and preset phase current mapping data, a reference phase current effective value is determined.

[0019] Preferably, the preset phase current mapping data includes preset motor data and preset phase current effective values ​​corresponding to the preset motor data;

[0020] The reference phase current effective value is the first phase current effective value or the second phase current effective value;

[0021] The first phase current effective value is a preset phase current effective value corresponding to preset motor data identical to the second motor data;

[0022] The second phase current effective value is a value obtained by interpolating two adjacent phase current effective values, and the two adjacent phase current effective values ​​are respectively preset phase current effective values ​​corresponding to two preset motor data adjacent to the second motor data.

[0023] Preferably, the second motor data includes motor speed and motor torque.

[0024] Preferably, determining the first phase current deviation rate based on the measured phase current effective value and the reference phase current effective value includes:

[0025] Determining a phase current deviation value based on the measured phase current effective value and the reference phase current effective value;

[0026] A first phase current deviation rate is determined based on the phase current deviation value and the reference phase current effective value.

[0027] Preferably, performing demagnetization detection based on the first phase current deviation rate and determining the demagnetization detection result includes:

[0028] When the first phase current deviation rate is less than a first deviation rate threshold, determining that the demagnetization detection result is that there is no demagnetization fault;

[0029] When the first phase current deviation rate is not less than a first deviation rate threshold, it is determined that the demagnetization detection result is that a demagnetization fault exists.

[0030] Preferably, the demagnetization fault is a power limiting demagnetization fault or a severe demagnetization fault;

[0031] The power limiting demagnetization fault is a demagnetization fault in which the first phase current deviation rate is less than a second deviation rate threshold;

[0032] The severe demagnetization fault is a demagnetization fault in which the first phase current deviation rate is not less than a second deviation rate threshold.

[0033] Preferably, the severe demagnetization fault is a primary severe demagnetization fault or a secondary severe demagnetization fault;

[0034] The first-level severe demagnetization fault is a severe demagnetization fault whose current duration is less than a first time threshold;

[0035] The secondary severe demagnetization fault is a severe demagnetization fault whose current duration is not less than the first time threshold;

[0036] The current duration is a duration in which the first phase current deviation rate is not less than a second deviation rate threshold.

[0037] Preferably, the secondary severe demagnetization fault includes a recoverable demagnetization fault or an irrecoverable demagnetization fault;

[0038] The recoverable demagnetization fault is a secondary severe demagnetization fault with a current fault number less than a preset number;

[0039] The irreversible demagnetization fault is a secondary severe demagnetization fault in which the current fault number is not less than a preset number;

[0040] The current fault number is the number of times the secondary severe demagnetization fault occurs.

[0041] Preferably, the current fault number is the number of times the secondary severe demagnetization fault occurs within a preset time period;

[0042] The preset time period is determined based on the current time corresponding to the measured motor data and a preset duration.

[0043] Preferably, after performing demagnetization detection based on the first phase current deviation rate and determining the demagnetization detection result, the motor demagnetization detection processing method further includes:

[0044] When the demagnetization detection result shows that there is no demagnetization fault, controlling the motor to work based on the demand control strategy;

[0045] When the demagnetization detection result indicates that a demagnetization fault exists, the motor is controlled to operate based on a protection control strategy.

[0046] Preferably, the controlling the motor to work based on a demand control strategy comprises: controlling the motor to work based on demand power;

[0047] The controlling the motor to work based on the protection control strategy includes: controlling the motor to work based on the protection power;

[0048] The protection power is less than the required power.

[0049] Preferably, the control motor works based on the protection power, including:

[0050] When the demagnetization detection result indicates that there is a power-limited demagnetization fault, based on a first protection strategy corresponding to the power-limited demagnetization fault, controlling the motor to operate based on a first protection power;

[0051] When the demagnetization detection result indicates that a severe demagnetization fault exists, based on a second protection strategy corresponding to the severe demagnetization fault, controlling the motor to operate based on a second protection power;

[0052] The second protection power is smaller than the first protection power.

[0053] Preferably, the first protection strategy corresponding to the power-limited demagnetization fault controls the motor to operate based on a first protection power, including:

[0054] Based on the mapping relationship between the first phase current deviation rate and the demagnetization limit power, determine a first deviation rate interval, a first calibration time, and a first protection power corresponding to the first phase current deviation rate;

[0055] Obtaining a first duration of the first phase current deviation rate within the first deviation rate interval;

[0056] When the first duration is greater than the first rated time, the motor is controlled to operate based on the first protection power.

[0057] Preferably, after controlling the motor to operate based on a first protection power according to the first protection strategy corresponding to the power-limited demagnetization fault, the motor demagnetization detection and processing method further includes:

[0058] Based on the measured motor data, determine the second phase current deviation rate;

[0059] Determine a second deviation rate interval and a second calibration time corresponding to the second phase current deviation rate based on the second phase current deviation rate and the demagnetization limited power recovery mapping data;

[0060] Obtaining a second duration of the second phase current deviation rate within the second deviation rate interval;

[0061] When the second duration is greater than the second rated time, the motor is controlled to operate based on the required power.

[0062] Preferably, the controlling the motor to operate based on the demand control strategy includes: controlling the motor to operate based on a first carrier frequency corresponding to a normal working state;

[0063] The controlling the motor to operate based on the protection control strategy includes: controlling the motor to operate based on a second carrier frequency corresponding to a demagnetization fault state;

[0064] The second carrier frequency is greater than or equal to the first carrier frequency.

[0065] Preferably, the controlling the motor to operate based on the second carrier frequency corresponding to the demagnetization fault state includes:

[0066] Determining a demagnetization fault level based on the demagnetization detection result;

[0067] The protection carrier frequency corresponding to the demagnetization fault level is determined as the second carrier frequency corresponding to the demagnetization fault state, and the motor is controlled to operate based on the second carrier frequency corresponding to the demagnetization fault state.

[0068] A controller includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the above-mentioned motor demagnetization detection and processing method is implemented.

[0069] A motor control system comprises a motor and the above-mentioned controller, wherein the controller is connected to the motor.

[0070] A car comprises the above motor control system.

[0071] A computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the motor demagnetization detection and processing method is implemented.

[0072] In the above-mentioned motor demagnetization detection processing method, controller, system, automobile and storage medium, based on the measured motor data of two different dimensions, namely the first motor data and the second motor data, the first phase current deviation rate is calculated, and then demagnetization detection is performed based on the first phase current deviation rate to determine the demagnetization detection result. Since the phase current detection process generally does not require additional detection using a voltage sensor or a voltage detection circuit, the cost of motor demagnetization detection can be effectively reduced, and the operational complexity of the demagnetization detection can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative labor.

[0074] Figure 1 is a flow chart of a motor demagnetization detection and processing method in one embodiment of the present invention;

[0075] Figure 2 yes Figure 1 A flow chart of step S102;

[0076] Figure 3 yes Figure 2 A flow chart of step S203;

[0077] Figure 4 yes Figure 1 A flow chart of step S103;

[0078] Figure 5 yes Figure 1 A flow chart after step S103;

[0079] Figure 6 yes Figure 5 A flowchart of a specific implementation of step S502;

[0080] Figure 7 yes Figure 6 A flow chart of step S601;

[0081] Figure 8 yes Figure 6 A flow chart after step S601;

[0082] Fig. 9 yes Figure 5 A flowchart of another specific implementation of step S502. DETAILED DESCRIPTION

[0083] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0084] The motor demagnetization detection and processing method provided in the embodiment of the present invention can be applied in a controller connected to the motor to perform demagnetization detection on the motor and control the motor to perform different operations according to the demagnetization detection result. The motor here can be a permanent magnet motor, specifically a permanent magnet synchronous motor.

[0085] For example, the motor may be a motor used in a car, and the controller may be a controller on the car connected to the motor. The controller here may be a controller dedicated to controlling the operation of the motor, or may be a controller integrated with other functions on the car.

[0086] In one embodiment, if Figure 1 As shown, a motor demagnetization detection and processing method is provided, and the method is applied to a controller connected to the motor as an example for description, including the following steps:

[0087] S101: Acquire measured motor data, where the measured motor data includes first motor data and second motor data;

[0088] S102: Determine a first phase current deviation rate based on first motor data and second motor data;

[0089] S103: Perform demagnetization detection based on the first phase current deviation rate and determine a demagnetization detection result.

[0090] The measured motor data refers to the data related to the motor collected in real time, and the measured motor data is data that can be used to calculate the phase current deviation rate. The first motor data and the second motor data are two sets of motor data of different dimensions collected in real time.

[0091] As an example, in step S101, the controller may obtain measured motor data corresponding to the motor, for example, the measured motor data may be collected through an existing detection circuit / detection device connected to the motor, and the measured motor data may include first motor data and second motor data, and the first motor data and the second motor data are two data required for calculating the phase current deviation rate. Generally speaking, the phase current detection process does not need to use a voltage sensor or a voltage detection circuit for detection, which can effectively avoid the cost of adding an additional voltage sensor or a voltage detection circuit.

[0092] The first phase current deviation rate refers to the first phase current deviation rate determined according to the measured motor data, and is the phase current deviation rate used to analyze and determine the demagnetization detection result.

[0093] As an example, in step S102, after acquiring the motor data of two different dimensions, the first motor data and the second motor data, the controller may use a preset phase current deviation rate calculation logic to calculate the first motor data and the second motor data respectively to determine the first phase current deviation rate. The phase current deviation rate calculation logic here may be to calculate two sets of phase current effective values ​​based on motor data of different dimensions, and then use the deviation degree of the two sets of phase current effective values ​​to determine the corresponding phase current deviation rate processing logic.

[0094] As an example, in step S103, after determining the first phase current deviation rate corresponding to the motor, the controller may compare the first phase current deviation rate with a preset condition for evaluating whether there is a demagnetization fault. When the first phase current deviation rate does not meet the preset condition, it can be determined that there is no demagnetization fault, and a demagnetization detection result indicating that there is no demagnetization fault is output; when the first phase current deviation rate meets the preset condition, it can be determined that there is a demagnetization fault, and a demagnetization detection result indicating that there is a demagnetization fault is output, so as to evaluate whether there is a demagnetization fault in the motor according to the first phase current deviation rate. Compared with the traditional detection scheme based on magnetic flux information and power deviation, demagnetization detection based on phase current deviation rate can effectively reduce the cost of demagnetization detection and reduce the operational complexity of demagnetization detection.

[0095] In this embodiment, based on the measured motor data of two different dimensions, namely the first motor data and the second motor data, the first phase current deviation rate is calculated, and then demagnetization detection is performed based on the first phase current deviation rate to determine the demagnetization detection result. Since the phase current detection process generally does not require additional detection using a voltage sensor or a voltage detection circuit, the cost of motor demagnetization detection can be effectively reduced, and the operational complexity of the demagnetization detection can be reduced.

[0096] In one embodiment, if Figure 2 As shown, step S102, i.e. determining the first phase current deviation rate based on the first motor data and the second motor data, includes:

[0097] S201: Determine a measured phase current effective value based on the first motor data;

[0098] S202: Determine a reference phase current effective value based on the second motor data;

[0099] S203: Determine a first phase current deviation rate based on the measured phase current effective value and the reference phase current effective value.

[0100] The measured phase current effective value refers to the phase current effective value determined based on the first motor data, and the reference phase current effective value refers to the phase current effective value determined based on the second motor data. The phase current effective value refers to the square root value of the sum of the squares of the currents of each phase of the motor.

[0101] As an example, in step S201, after acquiring the first motor data, the controller may process the input first motor data based on the phase current deviation rate calculation logic corresponding to the first motor data to determine the measured phase current effective value.

[0102] As an example, in step S202, after acquiring the second motor data, the controller may process the input second motor data based on the phase current deviation rate calculation logic corresponding to the second motor data to determine the reference phase current effective value.

[0103] For example, either one of the first motor data and the second motor data can be the actually detected current data, and the other can be non-current data. The phase current effective value can be directly calculated based on the actually detected current data, and the other phase current effective value can be determined based on the conversion relationship between the non-current data and the phase current effective value. Of the two phase current effective values ​​calculated here, one is the actually measured phase current effective value, and the other is the reference phase current effective value.

[0104] As an example, in step S203, after obtaining the measured phase current effective value and the reference phase current effective value, the controller may determine the first phase current deviation rate reflecting the degree of deviation between the measured phase current effective value and the reference phase current effective value. For example, the controller may determine the first phase current deviation rate based on the absolute value of the quotient of the phase current deviation value and the reference phase current effective value divided by each other.

[0105] In this embodiment, based on the actually detected first motor data and second motor data, the measured phase current effective value and the reference phase current effective value are respectively determined; then, according to the measured phase current effective value and the reference phase current effective value, the first phase current deviation rate is further calculated, and the calculation process is simple, which can reduce the complexity of operation; and, the detection process of the first motor data and the second motor data does not require the use of a voltage sensor or a voltage detection circuit for detection, which can effectively reduce the detection cost of the first phase current deviation rate.

[0106] In one embodiment, the first motor data includes motor current;

[0107] Step S201, i.e. determining the measured effective value of the phase current based on the first motor data, includes: determining the measured effective value of the phase current based on all motor currents within a preset period.

[0108] The preset cycle is a preset cycle for calculating the effective value of the phase current, and specifically may be a motor cycle in which the motor works once.

[0109] As an example, the controller can detect the motor current through an existing detection circuit / detection device for detecting current, and then perform root mean square calculation on all motor currents detected within a preset period to output the corresponding measured phase current effective value. It can be understood that the motor current can be detected using an existing detection circuit / detection device without using a voltage sensor or a voltage detection circuit, so that the detection cost of the measured phase current effective value is low, and the calculation process is simple, which can effectively reduce the operational complexity of demagnetization detection.

[0110] In one embodiment, step S202, ie, determining a reference phase current effective value based on the second motor data, includes: determining a reference phase current effective value based on the second motor data and preset phase current mapping data.

[0111] The preset phase current mapping data is pre-set data used to reflect the mapping relationship between the preset motor data and the preset phase current effective value, that is, each preset phase current mapping data is a set of data formed by the preset motor data and the preset phase current effective value. For example, the second motor data can be data for calculating the motor power, and the preset phase current mapping data can be constructed by using the mapping relationship between the motor power and the phase current effective value.

[0112] As an example, before step S101, that is, before obtaining the measured motor data, the motor can be tested first to obtain the test motor data and the test phase current effective value corresponding thereto, and the preset phase current mapping data can be constructed based on the mapping relationship between the test motor data and the test phase current effective value. The test motor data here is the motor data of the same dimension as the second motor data, for example, both can be motor power, or both can include motor speed and motor torque. In this example, the test motor data can be determined as preset motor data. Accordingly, the multiple test phase current effective values ​​corresponding to the same test motor data (preset motor data) obtained by multiple tests can be processed, for example, after removing the abnormal values, the mean value can be processed to determine the mean of the multiple test phase current effective values ​​as the corresponding preset phase current effective value corresponding to the test motor data (preset motor data).

[0113] As an example, the controller can match the actually detected second motor data with the preset phase current mapping data to determine at least one preset motor data that is the same as or close to the second motor data, and then process the preset phase current effective value corresponding to the determined at least one preset motor data to determine it as the reference phase current effective value. It can be understood that by querying the preset phase current mapping data based on the second motor data, the reference phase current effective value can be quickly determined, reducing the operational complexity of the demagnetization detection process.

[0114] It can be understood that in order to avoid the need to use additional voltage sensors or voltage detection circuits for detection during the motor demagnetization detection process, preset phase current mapping data can be constructed based on the mapping relationship between test motor data and test phase current effective values ​​that do not require the collection of voltage sensors or voltage detection circuits for detection. This allows for the subsequent determination of the reference phase current effective value based on the second motor data and the preset phase current mapping data without the need to use voltage sensors or voltage detection circuits for detection, thereby avoiding the increase in detection costs caused by the additional voltage sensors or voltage detection circuits, and thereby reducing the motor demagnetization detection cost.

[0115] In one embodiment, the preset phase current mapping data includes preset motor data and a preset phase current effective value corresponding to the preset motor data;

[0116] The reference phase current effective value is the first phase current effective value or the second phase current effective value;

[0117] The first phase current effective value is a preset phase current effective value corresponding to preset motor data identical to the second motor data;

[0118] The second phase current effective value is a value obtained by interpolating two adjacent phase current effective values, and the two adjacent phase current effective values ​​are respectively preset phase current effective values ​​corresponding to two preset motor data adjacent to the second motor data.

[0119] As an example, the controller may match the second motor data with the preset motor data of a plurality of preset phase current mapping data, so as to determine the reference phase current effective value by adopting different strategies according to the matching result. For example, when there is a preset motor data identical to the second motor data among the plurality of preset motor data, when the preset phase current effective value corresponding to the preset motor data is determined as the first phase current effective value, the first phase current effective value may be directly determined as the reference phase current effective value to ensure the efficiency and accuracy of determining the reference phase current effective value. Accordingly, when there is no preset motor data identical to the second motor data among the plurality of preset motor data, two preset motor data adjacent to the second motor data may be determined, and then the preset phase current effective values ​​corresponding to the two preset motor data may be determined as two adjacent phase current effective values; then, algorithms such as, but not limited to, linear interpolation algorithm, least squares interpolation method and Lagrange interpolation method may be adopted to interpolate the two adjacent phase current effective values ​​to determine the reference phase current effective value, which may ensure the reliability of the determined reference phase current effective value and avoid the situation where the reference phase current effective value cannot be queried and determined.

[0120] In one embodiment, the second motor data includes motor speed and motor torque.

[0121] As an example, the second motor data may include the motor speed and the motor torque. Accordingly, the preset phase current mapping data is mapping data for reflecting the mapping relationship between the speed-torque-phase current effective value. For example, in the process of testing the motor in advance, when the motor is in normal working state, multiple groups of test working points formed by different motor torques (such as 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% and 100% peak torque) corresponding to different motor speeds (10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% and 100% peak torque) are determined, and the test phase current effective value is collected at each test working point. Based on the motor speed, motor torque and test phase current effective value corresponding to each test working point, a preset phase current mapping data with the input of motor speed and motor torque and the output of phase current effective value under normal working state is prepared, so that the corresponding reference phase current effective value can be quickly obtained according to the actual detected motor speed and motor torque by looking up the table later, thereby reducing the operational complexity of the demagnetization detection process; moreover, the two second motor data of motor speed and motor torque do not need to be detected by voltage sensor or voltage detection circuit, which can effectively reduce its detection cost.

[0122] In one embodiment, if Figure 3 As shown, step S203, i.e. determining the first phase current deviation rate based on the measured phase current effective value and the reference phase current effective value, includes:

[0123] S301: Determine a phase current deviation value based on the measured phase current effective value and the reference phase current effective value;

[0124] S302: Determine a first phase current deviation rate based on the phase current deviation value and a reference phase current effective value.

[0125] As an example, in step S301, the controller may determine the phase current deviation value based on the measured phase current effective value and the reference phase current effective value. For example, the difference between the measured phase current effective value and the reference phase current effective value may be determined as the phase current deviation value, where the phase current deviation value may effectively reflect the degree of deviation of the phase current effective value determined based on the first motor data and the second motor data. Generally speaking, the larger the calculated phase current deviation value, the greater the difference in the phase current effective values ​​calculated using the two motor data.

[0126] As an example, in step S302, after determining the phase current deviation value and the reference phase current effective value, the controller may divide the phase current deviation value and the reference phase current effective value, and determine the first phase current deviation rate based on the absolute value of the quotient between the two. The value range of the first phase current deviation rate is 0-1, so as to ensure that the first phase current deviation rate calculated based on the measured motor data detected at different times is comparable, which helps to ensure the accuracy of subsequent demagnetization detection based on the first phase current deviation rate.

[0127] For example, the measured phase current effective value determined based on the first motor data is I1, and the reference phase current effective value determined based on the second motor data is I2. When the reference phase current effective value I2 is determined as the reference phase current effective value, the first phase current deviation rate Irms determined therefrom can be calculated using the following formula: The calculation process is simple and convenient, so that the first phase current deviation rate Irms calculated according to the above formula is comparable.

[0128] In one embodiment, if Figure 4 As shown, step S103, i.e., performing demagnetization detection based on the first phase current deviation rate to determine the demagnetization detection result, includes:

[0129] S401: When the first phase current deviation rate is less than a first deviation rate threshold, determining that the demagnetization detection result is that there is no demagnetization fault;

[0130] S402: When the first phase current deviation rate is not less than a first deviation rate threshold, determine that the demagnetization detection result is that a demagnetization fault exists.

[0131] The first deviation rate threshold is a preset deviation rate threshold for evaluating whether a demagnetization fault exists. For example, the first deviation rate threshold may be set to 5%.

[0132] As an example, after obtaining the first-phase current deviation rate, the controller may compare the first-phase current deviation rate with a pre-set first deviation rate threshold; when the first-phase current deviation rate is less than the first deviation rate threshold, it can be determined that the first-phase current deviation rate corresponding to the measured motor data is smaller, and the possibility of motor demagnetization is lower, and therefore, the demagnetization detection result is determined to be that there is no demagnetization fault; conversely, when the first-phase current deviation rate is not less than the first deviation rate threshold, it can be determined that the first-phase current deviation rate corresponding to the measured motor data is larger, and the possibility of motor demagnetization is higher, and therefore, the demagnetization detection result can be determined to be that there is a demagnetization fault.

[0133] In this example, a demagnetization detection result indicating whether a demagnetization fault exists is determined based on a comparison result between the first phase current deviation rate and the first deviation rate threshold, which can effectively reduce the cost and operation complexity of the demagnetization detection.

[0134] In one embodiment, the demagnetization fault is a power limiting demagnetization fault or a severe demagnetization fault;

[0135] The power limiting demagnetization fault is a demagnetization fault in which the first phase current deviation rate is less than a second deviation rate threshold;

[0136] The severe demagnetization fault is a demagnetization fault in which the first phase current deviation rate is not less than a second deviation rate threshold.

[0137] The second deviation rate threshold is a deviation rate threshold used to evaluate the severity of the demagnetization fault, for example, a deviation rate threshold used to distinguish between a power-limited demagnetization fault and a severe demagnetization fault. Generally speaking, the second deviation rate threshold is greater than the first deviation rate threshold, for example, the first deviation rate threshold can be set to 5%, and the second deviation rate threshold can be set to 10%.

[0138] As an example, when the first-phase current deviation rate is not less than the first deviation rate threshold and the controller determines that the demagnetization detection result is a demagnetization fault, the controller also needs to compare the first-phase current deviation rate with a preset second deviation rate threshold; when the first-phase current deviation rate is less than the second deviation rate threshold, it can be determined that the severity of the demagnetization fault is low, and the demagnetization detection result can be determined to be a power-limited demagnetization fault, that is, the demagnetization fault level is determined to be a power-limited demagnetization fault; conversely, when the first-phase current deviation rate is not less than the second deviation rate threshold, it can be determined that the severity of the demagnetization fault is high, and the demagnetization detection result can be determined to be a severe demagnetization fault. In this example, the power-limited demagnetization fault is a demagnetization fault in which the first-phase current deviation rate is between the first deviation rate threshold and the second deviation rate threshold; accordingly, a severe demagnetization fault is a demagnetization fault in which the first-phase current deviation rate is not less than the second deviation rate threshold.

[0139] In this example, when the first phase current deviation rate is not less than the first deviation rate threshold and the demagnetization detection result is determined to be the presence of a demagnetization fault, based on the comparison result of the first phase current deviation rate and the second deviation rate threshold, it is distinguished whether the demagnetization fault is a limited power demagnetization fault or a severe demagnetization fault, so that the motor can be controlled to perform different protection measures based on the demagnetization fault level to achieve the purpose of motor protection.

[0140] In one embodiment, the severe demagnetization fault is a primary severe demagnetization fault or a secondary severe demagnetization fault;

[0141] The first-level severe demagnetization fault is a severe demagnetization fault whose current duration is less than a first time threshold;

[0142] The secondary severe demagnetization fault is a severe demagnetization fault whose current duration is not less than the first time threshold;

[0143] The current duration is a duration in which the first phase current deviation rate is not less than a second deviation rate threshold.

[0144] The current duration refers to the duration during which the first phase current deviation rate is not less than the second deviation rate threshold, specifically, the duration during which the first phase current deviation rate is continuously detected to be not less than the second deviation rate threshold.

[0145] The first time threshold is a time threshold preset for classifying the fault level of the severe demagnetization fault. As an example, the first time threshold is a time threshold for distinguishing a first-level severe demagnetization fault from a second-level severe demagnetization fault, where the fault level of the first-level severe demagnetization fault is lower than the fault level of the second-level severe demagnetization fault.

[0146] As an example, the controller starts from the initial moment t1 when it detects that the first phase current deviation rate is not less than the second deviation rate threshold, and accumulates the current duration of the first phase current deviation rate not less than the second deviation rate threshold. The current duration can effectively reflect how long the motor has a serious demagnetization fault; then, the current duration is compared with the preset first time threshold; when the current duration is less than the first time threshold, it can be determined that the current duration of the serious demagnetization fault is short, and the demagnetization detection result can be further determined to be a first-level serious demagnetization fault; conversely, when the current duration is not less than the first time threshold, it can be determined that the current duration of the serious demagnetization fault is long, and the demagnetization detection result can be further determined to be a second-level serious demagnetization fault. In this example, a first-level serious demagnetization fault is a serious demagnetization fault whose current duration is less than the first time threshold; accordingly, a second-level serious demagnetization fault is a serious demagnetization fault whose current duration is not less than the first time threshold.

[0147] In this embodiment, after determining the current duration during which the first phase current deviation rate is not less than the second deviation rate threshold, based on the comparison result between the current duration and the first time threshold, it is distinguished whether the severe demagnetization fault that has occurred is a first-level severe demagnetization fault or a second-level severe demagnetization fault, so as to subsequently control the motor to execute different protection measures based on the demagnetization fault level to achieve the purpose of motor protection.

[0148] In one embodiment, the secondary severe demagnetization fault includes a recoverable demagnetization fault or an irrecoverable demagnetization fault;

[0149] The recoverable demagnetization fault is a secondary severe demagnetization fault with a current fault number less than a preset number;

[0150] The irreversible demagnetization fault is a secondary severe demagnetization fault in which the current fault number is not less than a preset number;

[0151] The current fault number is the number of times the secondary severe demagnetization fault occurs.

[0152] The preset number of times is a preset threshold used to evaluate whether the demagnetization fault is recoverable.

[0153] As an example, when the current duration is not less than the first time threshold, after the controller determines that the demagnetization detection result is a secondary severe demagnetization fault, it is necessary to update the current fault number corresponding to the secondary severe demagnetization fault, that is, the current fault number = the existing fault number + 1. For example, after the motor is powered on, each time a secondary severe demagnetization fault is detected, it is necessary to add 1 to the existing fault number to obtain the current fault number. When the current fault number is less than the preset number, the controller determines that the number of secondary severe demagnetization faults is small, and the demagnetization detection result can be further determined to be a recoverable demagnetization fault; conversely, when the current fault number is not less than the preset number, it is determined that the number of secondary severe demagnetization faults is large, that is, secondary severe demagnetization faults occur frequently, so as to determine that the demagnetization detection result is an irrecoverable demagnetization fault.

[0154] A recoverable demagnetization fault refers to a severe demagnetization fault when the current fault number corresponding to the secondary severe demagnetization fault is less than the preset number; for example, a recoverable demagnetization fault may be a severe demagnetization fault that allows the motor to resume normal operation by limiting power without powering off the motor. Correspondingly, an irrecoverable demagnetization fault refers to a severe demagnetization fault when the current fault number corresponding to the secondary severe demagnetization fault is less than the preset number; for example, an irrecoverable demagnetization fault may be a severe demagnetization fault that cannot allow the motor to resume normal operation without powering off the motor.

[0155] In this embodiment, when it is determined that a secondary severe demagnetization fault has occurred, it is determined whether the secondary severe demagnetization fault occurs frequently based on a comparison result of the current number of secondary severe demagnetization faults counted and the preset number, and the secondary severe demagnetization fault is further divided into recoverable demagnetization faults and irrecoverable demagnetization faults to ensure the accuracy of the demagnetization detection result.

[0156] In one embodiment, the current fault number is the number of times the secondary severe demagnetization fault occurs within a preset time period;

[0157] The preset time period is determined based on the current time corresponding to the measured motor data and a preset duration.

[0158] The preset time period is a preset time period, which can be determined based on the current time and a preset duration.

[0159] As an example, when the controller determines that the demagnetization detection result is a secondary severe demagnetization fault based on the measured motor data collected at a certain time t3, the current time corresponding to the measured motor data can be used as the end time t3, and the difference between the end time t3 and the preset time length Ts is the start time t3-Ts, and the current fault number of the demagnetization detection result being a secondary severe demagnetization fault within the preset time period from the start time t3-Ts to the end time t3 is counted; when the current fault number is less than the preset number, the controller determines that the number of secondary severe demagnetization faults occurring within the preset time period is small, and the demagnetization detection result can be further determined to be a recoverable demagnetization fault; conversely, when the current fault number is not less than the preset number, it is determined that the number of secondary severe demagnetization faults occurring within the preset time period is large, and the demagnetization detection result can be further determined to be an irreversible demagnetization fault.

[0160] In this embodiment, a preset time period is determined based on the current time and a preset duration, and a comparison result of the current number of secondary severe demagnetization faults occurring within the preset time period with the preset number is used to determine whether secondary severe demagnetization faults occur frequently within a short time period, and then the secondary severe demagnetization faults are determined as recoverable demagnetization faults and irrecoverable demagnetization faults to ensure the accuracy of the demagnetization detection results.

[0161] In one embodiment, if Figure 5 As shown, after step S103, that is, after performing demagnetization detection based on the first phase current deviation rate and determining the demagnetization detection result, the motor demagnetization detection processing method further includes:

[0162] S501: When the demagnetization detection result shows that there is no demagnetization fault, the motor is controlled to work based on the demand control strategy;

[0163] S502: When the demagnetization detection result shows that there is a demagnetization fault, the motor is controlled to operate based on a protection control strategy.

[0164] Among them, the demand control strategy refers to the strategy of controlling the motor operation based on actual demand, and the protection control strategy refers to the strategy of controlling the motor operation based on protection demand.

[0165] As an example, when the demagnetization detection result shows that there is no demagnetization fault, the controller can control the motor to work based on the demand control strategy. Specifically, the motor can be controlled to work according to the actual needs of the scene where the motor is located to ensure that when there is no demagnetization fault, the motor can meet its actual needs; conversely, when the demagnetization detection result shows that there is a demagnetization fault, the motor can be controlled to work based on the protection control strategy. Specifically, the corresponding protection measures can be determined according to the demagnetization fault level to control the motor to achieve the purpose of motor protection. In this example, based on the different demagnetization detection results, the motor is controlled to work based on the demand control strategy or the protection control strategy to achieve a control effect that takes into account both actual needs and motor protection.

[0166] In one embodiment, after step S501, that is, after controlling the motor to work based on the demand control strategy, the motor demagnetization detection processing method also includes: updating the current state corresponding to the motor to a normal working state, for example, outputting a normal working flag to enable the user to understand that the motor can work normally based on actual needs.

[0167] Accordingly, after step S502, that is, after controlling the motor to work based on the protection control strategy, the motor demagnetization detection processing method also includes: updating the current state corresponding to the motor to a demagnetization fault state, for example, outputting a demagnetization fault flag to let the user know that the motor has a demagnetization fault.

[0168] In one embodiment, step S501, i.e., controlling the motor to work based on the demand control strategy, includes: controlling the motor to work based on the demand power;

[0169] Accordingly, in step S502, controlling the motor to work based on the protection control strategy includes: controlling the motor to work based on the protection power;

[0170] Among them, the protection power is less than the required power.

[0171] Among them, the required power refers to the power determined according to the actual demand, which can be understood as the power determined according to the actual demand when the motor is in normal working state. The protection power is the power determined to protect the motor, which can be understood as the power determined to achieve the purpose of motor protection when the motor is in the demagnetization fault state. Generally speaking, the protection power is less than the required power, so that when the motor is in the demagnetization fault state, it works based on the protection power smaller than the required power, so as to limit the power of the motor and achieve the effect of motor protection.

[0172] As an example, in step S501, when the demagnetization detection result of the motor shows that there is no demagnetization fault, the controller controls the motor to operate based on the demand control strategy, specifically including: determining the required power corresponding to the actual demand according to the actual demand of the environment, and controlling the motor to operate based on the required power to ensure the normal operation of the motor.

[0173] As an example, in step S502, when the demagnetization detection result of the motor is that there is a demagnetization fault, the controller controls the motor to work based on the protection control strategy, specifically including: according to the specific demagnetization fault level, determining the protection power corresponding to the demagnetization fault level, and controlling the motor to work based on the protection power to ensure the operation of the motor during the demagnetization fault, thereby achieving the purpose of motor protection. It can be understood that when the motor is in a demagnetization fault state, the motor is controlled to work based on a protection power less than its required power to limit the power of the motor to achieve the purpose of motor protection.

[0174] In one embodiment, if Figure 6 As shown, in step S502, controlling the motor to work based on the protection power includes:

[0175] S601: When the demagnetization detection result indicates that there is a limited power demagnetization fault, based on a first protection strategy corresponding to the limited power demagnetization fault, control the motor to operate based on a first protection power;

[0176] S602: When the demagnetization detection result indicates that a severe demagnetization fault exists, based on a second protection strategy corresponding to the severe demagnetization fault, controlling the motor to operate based on a second protection power;

[0177] The second protection power is smaller than the first protection power.

[0178] Among them, the limited power demagnetization fault is a demagnetization fault in which the first phase current deviation rate is between the first deviation rate threshold and the second deviation rate threshold. The first protection strategy refers to the protection strategy executed when there is a limited power demagnetization fault. The first protection power refers to the protection power determined based on the first protection strategy, that is, the power required to control the operation of the motor in the event of a limited power demagnetization fault. Generally speaking, the first protection power is less than the required power. For example, the first protection power can be the product of the first coefficient and the required power. For example, the first coefficient here can be determined based on the first phase current deviation rate. The larger the first phase current deviation rate, the smaller the first coefficient. The value range of the first coefficient is 0-1.

[0179] As an example, in step S601, when the controller determines that the demagnetization detection result is a limited power demagnetization fault, that is, there is a demagnetization fault in which the first phase current deviation rate is between the first deviation rate threshold and the second deviation rate threshold, it is necessary to call the first protection strategy corresponding to the limited power demagnetization fault, determine the first protection power corresponding to the limited power demagnetization fault, and then control the motor to operate based on the first protection power to reduce the working power of the motor, thereby achieving the purpose of motor protection.

[0180] Among them, a severe demagnetization fault is a demagnetization fault in which the first phase current deviation rate is not less than the second deviation rate threshold. The second protection strategy refers to a protection strategy executed when a severe demagnetization fault exists. The second protection power refers to the protection power determined based on the second protection strategy, that is, the protection power required to control the operation of the motor in the event of a severe demagnetization fault. Generally speaking, the second protection power is less than the first protection power. For example, the second protection power can be the product of the second coefficient and the required power. For example, the second coefficient here can be determined based on the first phase current deviation rate. The larger the second phase current deviation rate, the smaller the second coefficient. The value range of the second coefficient is 0-1, and the second coefficient is less than the first coefficient. In this example, the second coefficient can be a fixed value, or it can match the demagnetization fault level. The higher the demagnetization fault level, the smaller the second coefficient.

[0181] As an example, in step S602, when the controller determines that the demagnetization detection result is a severe demagnetization fault, that is, there is a demagnetization fault in which the first phase current deviation rate is not less than the second deviation rate threshold, it is necessary to call the second protection strategy corresponding to the severe demagnetization fault, determine the second protection power corresponding to the severe demagnetization fault, and then control the motor to operate based on the second protection power to reduce the working power of the motor, thereby achieving the purpose of motor protection.

[0182] In one embodiment, if Figure 7 As shown, step S601, i.e., based on a first protection strategy corresponding to a power-limited demagnetization fault, controlling the motor to operate based on a first protection power, includes:

[0183] S701: Determine a first deviation rate interval, a first calibration time, and a first protection power corresponding to the first phase current deviation rate based on a mapping relationship between the first phase current deviation rate and the demagnetization limit power;

[0184] S702: Obtain a first duration of a first phase current deviation rate within a first deviation rate interval;

[0185] S703: When the first duration is greater than the first calibration time, control the motor to operate based on the first protection power.

[0186] The demagnetization power limit mapping relationship is a pre-set mapping relationship for recording different deviation rate intervals and different deviation rate intervals and their corresponding calibration times and protection powers. The demagnetization power limit mapping relationship may exist in the form of a data table or other data structures.

[0187] As an example, in step S701, when the controller executes the first protection strategy corresponding to the limited power demagnetization fault, it is necessary to first determine the deviation rate interval corresponding to the first phase current deviation rate in the demagnetization limited power mapping relationship as the first deviation rate interval based on the first phase current deviation rate and the pre-set demagnetization limited power mapping relationship, and determine the calibration time and protection power corresponding to the first deviation rate interval as the first calibration time and the first protection power, respectively, to ensure the determination efficiency of the first deviation rate interval, the first calibration time and the first protection power.

[0188] As an example, in step S702, when the controller determines that the demagnetization detection result is a limited power demagnetization fault, it needs to accumulate the first duration of the first phase current deviation rate in the first deviation rate interval. The first duration can reflect how long the first phase current deviation rate is in the first deviation rate interval.

[0189] As an example, in step S703, the controller may compare the first duration determined by the actual detection with the corresponding first calibration time. If the first duration is greater than the first calibration time, it is determined that the first phase current deviation rate is in the first deviation rate interval for a longer time. At this time, it is necessary to control the motor to work at power limit based on the first protection power corresponding to the first deviation rate interval to achieve the purpose of motor protection. In this example, after controlling the motor to work based on the first protection power, the controller also needs to update the current state corresponding to the motor to a power limit fault state, for example, output a power limit fault state bit to remind the user that there is a power limit demagnetization fault.

[0190] For example, the demagnetization limit power mapping relationship is shown in Table 1 below. When the first deviation rate threshold is 5%, and the second deviation rate threshold is 10%, and the first deviation rate interval corresponding to the first phase current deviation rate is [9%, 10%), when the duration of the first phase current deviation rate in the first deviation rate interval [9%, 10%) reaches the first calibration time of 18s, it is necessary to control the motor to operate based on the first protection power of 30%.

[0191] Table 1 Demagnetization limit power mapping relationship

[0192] Deviation rate range Calibration time Protection power Protect carrier frequency [5％,6％) 10s 50％ 10kHz [6％,7％) 12s 45％ 10kHz [7％,8％) 14s 40％ 10kHz [8％,9％) 16s 35％ 10kHz [9％,10％) 18s 30％ 10kHz

[0193] In this embodiment, based on the first phase current deviation rate lookup table, the first deviation rate interval and its corresponding first calibration time and first protection power can be quickly determined. When the first duration reaches the first calibration time, which is a prerequisite, the motor will be controlled to operate based on the first protection power to avoid the first phase current deviation rate occasionally being between the first deviation rate interval, requiring frequent adjustment of the motor power, and affecting the normal operation of the motor.

[0194] In one embodiment, if Figure 8 As shown, after step S601, that is, after controlling the motor to work based on the first protection power based on the first protection strategy corresponding to the power-limited demagnetization fault, the motor demagnetization detection processing method further includes:

[0195] S801: Determine a second phase current deviation rate based on measured motor data;

[0196] S802: Determine a second deviation rate interval and a second calibration time corresponding to the second phase current deviation rate based on the second phase current deviation rate and the demagnetization limited power recovery mapping data;

[0197] S803: Obtain a second duration of the second phase current deviation rate within a second deviation rate interval;

[0198] S804: When the second duration is greater than the second calibrated time, control the motor to operate based on the required power.

[0199] The second phase current deviation rate refers to the second phase current deviation rate determined according to the measured motor data, and the second phase current deviation rate is a measured value used to evaluate whether it is necessary to stop executing the first protection strategy corresponding to the power limiting demagnetization fault.

[0200] As an example, in step S801, after the controller controls the motor to operate based on the first protection power based on the first protection strategy corresponding to the limited power demagnetization fault, it needs to obtain the measured motor data corresponding to the motor, and determine the second phase current deviation rate based on the measured motor data. This process is the same as the process of determining the first phase current deviation rate. To avoid repetition, it will not be described here one by one.

[0201] Among them, the demagnetization power limit recovery mapping data is pre-set to record different deviation rate intervals and the calibration time, required power and protection carrier frequency corresponding to each deviation rate interval. The demagnetization power limit recovery mapping data can exist in the form of a data table or other data structure. When the motor is used in a car, its corresponding demagnetization power limit recovery mapping data can determine its corresponding calibration time, protection power and protection carrier frequency according to the bench temperature rise test and the vehicle dynamics requirements.

[0202] Among them, the second deviation rate interval refers to the deviation rate interval corresponding to the second phase current deviation rate recorded in the demagnetization limited power recovery mapping data. The second calibration time refers to the calibration time corresponding to the second deviation rate interval recorded in the demagnetization limited power recovery mapping data, specifically the calibration time used to evaluate whether it is necessary to control the motor for limited power recovery. For example, when the first deviation rate threshold is 5% and the second deviation rate threshold is 10%, the required power is set to 100% by default, and its pre-configured demagnetization limited power recovery mapping data is shown in Table 2 below.

[0203] Table 2 Demagnetization limit power recovery mapping data

[0204] Deviation rate range Calibration time Restoration power Protect carrier frequency (0,4％) 5s 100％ 10kHz [5％,6％) 5.5s 100％ 10kHz [6％,7％) 6s 100％ 10kHz [7％,8％) 6.5s 100％ 10kHz [8％,9％) 7s 100％ 10kHz [9％,10％) 7.5s 100％ 10kHz

[0205] As an example, in step S802, after determining the second phase current deviation rate, the controller may query the pre-set demagnetization limit power recovery mapping data based on the second phase current deviation rate, and determine the deviation rate interval corresponding to the second phase current deviation rate in the demagnetization limit power recovery mapping data as the second deviation rate interval, and determine the calibration time corresponding to the second deviation rate interval as the second calibration time.

[0206] As an example, in step S803, the controller needs to accumulate a second duration of the second phase current deviation rate within the second deviation rate interval, where the second duration can reflect how long the second phase current deviation rate is within the second deviation rate interval.

[0207] As an example, in step S804, the controller compares the actually detected second duration with the second calibration time in the demagnetization limited power recovery mapping data. If the second duration is greater than the second calibration time, it is determined that in the process of controlling the motor to work based on the first protection power, the detected second phase current deviation rate is at the second deviation rate threshold for a long time, and the severity of the limited power demagnetization fault has been eliminated or weakened to a certain extent. At this time, the motor can be controlled to work based on the required power, so that after the motor demagnetization phenomenon is eliminated or weakened, the motor can be controlled to work based on actual needs to ensure the normal operation of the motor.

[0208] In one embodiment, step S501, i.e., controlling the motor to operate based on a demand control strategy, includes: controlling the motor to operate based on a first carrier frequency corresponding to a normal working state;

[0209] Accordingly, in step S502, controlling the motor to operate based on the protection control strategy includes: controlling the motor to operate based on a second carrier frequency corresponding to the demagnetization fault state;

[0210] The second carrier frequency is greater than or equal to the first carrier frequency.

[0211] Among them, the first carrier frequency refers to the motor carrier frequency when the motor is in normal working state. The second carrier frequency refers to the motor carrier frequency when the motor is in demagnetization fault state. The motor carrier frequency refers to the frequency used to adjust the output waveform width in the motor controller. In PWM (Pulse Width Modulation) technology, the motor carrier frequency controls the size of the jump frequency in the PWM signal. This parameter has a direct impact on the efficiency and noise level of the motor. In addition, the motor carrier frequency can also be understood as a frequency range within which vibrations may cause damage to the motor. Generally speaking, the second carrier frequency is greater than or equal to the first carrier frequency, so that when the motor is in a demagnetization fault state, it works based on the larger second carrier frequency to achieve the effect of motor protection.

[0212] As an example, when the demagnetization detection result of the motor shows that there is no demagnetization fault, the controller controls the motor to operate based on the demand control strategy, specifically including: obtaining a first carrier frequency corresponding to the normal working state, where the first carrier frequency can be a pre-set carrier frequency corresponding to the normal working state, for example, the first carrier frequency can be set to 10kHz; then, controlling the motor to operate based on the first carrier frequency, that is, determining the carrier frequency of the motor to be the first carrier frequency, so as to ensure the normal operation of the motor.

[0213] As an example, when the demagnetization detection result of the motor is that there is a demagnetization fault, the controller controls the motor to operate based on the protection control strategy, specifically including: obtaining a second carrier frequency corresponding to the demagnetization fault state, where the second carrier frequency can be a pre-set carrier frequency corresponding to the demagnetization fault state, for example, when the first carrier frequency is 10kHz, the second carrier frequency can be set to 10kHz or 15kHz; then, controlling the motor to operate based on the second carrier frequency corresponding to the demagnetization fault state, that is, increasing the carrier frequency of the motor to the second carrier frequency corresponding to the demagnetization fault state, so as to achieve the purpose of motor protection.

[0214] In one embodiment, if Fig. 9 As shown, step S502, controlling the motor to operate based on a second carrier frequency corresponding to the demagnetization fault state, includes:

[0215] S901: Determine the demagnetization fault level based on the demagnetization detection result;

[0216] S902: Determine the protection carrier frequency corresponding to the demagnetization fault level as the second carrier frequency corresponding to the demagnetization fault state, and control the motor to operate based on the second carrier frequency corresponding to the demagnetization fault state.

[0217] As an example, in step S901, when the demagnetization detection result indicates that there is a demagnetization fault, the controller needs to determine the demagnetization fault level based on the demagnetization detection result. In this example, the demagnetization fault level includes a power-limited demagnetization fault and a severe demagnetization fault, and the severe demagnetization fault includes a first-level severe demagnetization fault and a second-level severe demagnetization fault. The second-level severe demagnetization fault further includes a recoverable demagnetization fault and an irrecoverable demagnetization fault. Here, the demagnetization fault levels of the power-limited demagnetization fault, the first-level severe demagnetization fault, the recoverable demagnetization fault, and the irrecoverable demagnetization fault increase in sequence, and their demagnetization severity increases in sequence.

[0218] As an example, in step S902, after obtaining the demagnetization fault level, the controller can look up a table based on the demagnetization fault level to determine the protection carrier frequency corresponding to the demagnetization fault level, determine the second carrier frequency corresponding to the demagnetization fault state based on the protection carrier frequency corresponding to the demagnetization fault level, and control the motor to work based on the second carrier frequency corresponding to the demagnetization fault state, specifically increasing the carrier frequency of the motor to the second carrier frequency to achieve the purpose of motor protection. Generally speaking, the higher the demagnetization fault level, the larger the corresponding protection carrier frequency. For example, when the demagnetization fault level is a power-limited demagnetization fault, the corresponding protection carrier frequency is 10kHz; when the demagnetization fault level is a severe demagnetization fault level, the corresponding protection carrier frequency is 15kHz.

[0219] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0220] In one embodiment, a controller is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the motor demagnetization detection processing method in the above embodiment is implemented, for example Figure 1 S101-S103 as shown, or Figures 2 to 9 To avoid repetition, it will not be described here.

[0221] In one embodiment, a motor control system is provided, including a motor and the controller in the above embodiment. The controller is connected to the motor and is used to perform demagnetization detection on the motor and control the motor to perform different operations according to the demagnetization detection result. In this example, the controller includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the motor demagnetization detection processing method in the above embodiment is implemented, for example Figure 1 S101-S103 as shown, or Figures 2 to 9 To avoid repetition, it will not be described here.

[0222] In one embodiment, a car is provided, including a motor control system arranged on the car, the motor control system includes the controller in the above embodiment and a motor connected to the controller, the controller implements the motor demagnetization detection and processing method in the above embodiment to control the operation of the motor, to avoid repetition, it will not be repeated here.

[0223] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the motor demagnetization detection processing method in the above embodiment is implemented, for example Figure 1 S101-S103 as shown, or Figures 2 to 9 To avoid repetition, it will not be described here.

[0224] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0225] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0226] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A motor demagnetization detection and processing method, characterized in that: include: Acquire measured motor data, the measured motor data comprising first motor data and second motor data, the first motor data being actually detected current data; Determine the measured phase current effective value based on the first motor data; Determine a reference phase current effective value based on the second motor data and preset phase current mapping data, wherein the second motor data includes motor speed and motor torque, and the preset phase current mapping data is mapping data used to reflect the mapping relationship between speed-torque-phase current effective value; determine a first phase current deviation rate based on the measured phase current effective value and the reference phase current effective value, wherein the phase current effective value refers to the square root value of the sum of the squares of the currents of each phase of the motor; Demagnetization detection is performed based on the first phase current deviation rate to determine the demagnetization detection result.

2. The motor demagnetization detection and processing method according to claim 1, characterized in that: The first motor data includes motor current; and determining the measured phase current effective value based on the first motor data includes: Based on all the motor currents within a preset period, the measured phase current effective value is determined.

3. The motor demagnetization detection and processing method according to claim 1, characterized in that: The preset phase current mapping data includes preset motor data and a preset phase current effective value corresponding to the preset motor data; The reference phase current effective value is the first phase current effective value or the second phase current effective value; The first phase current effective value is a preset phase current effective value corresponding to preset motor data identical to the second motor data; The second phase current effective value is a value obtained by interpolating two adjacent phase current effective values, and the two adjacent phase current effective values ​​are respectively preset phase current effective values ​​corresponding to two preset motor data adjacent to the second motor data.

4. The motor demagnetization detection and processing method according to claim 1, characterized in that: The determining of the first phase current deviation rate based on the measured phase current effective value and the reference phase current effective value comprises: Determining a phase current deviation value based on the measured phase current effective value and the reference phase current effective value; A first phase current deviation rate is determined based on the phase current deviation value and the reference phase current effective value.

5. The motor demagnetization detection and processing method according to claim 1, characterized in that: The performing demagnetization detection based on the first phase current deviation rate and determining the demagnetization detection result includes: When the first phase current deviation rate is less than a first deviation rate threshold, determining that the demagnetization detection result is that there is no demagnetization fault; When the first phase current deviation rate is not less than a first deviation rate threshold, it is determined that the demagnetization detection result is that a demagnetization fault exists.

6. The motor demagnetization detection and processing method according to claim 5, characterized in that: The demagnetization fault is a power-limited demagnetization fault or a severe demagnetization fault; The power limiting demagnetization fault is a demagnetization fault in which the first phase current deviation rate is less than a second deviation rate threshold; The severe demagnetization fault is a demagnetization fault in which the first phase current deviation rate is not less than a second deviation rate threshold.

7. The motor demagnetization detection and processing method according to claim 6, characterized in that: The severe demagnetization fault is a primary severe demagnetization fault or a secondary severe demagnetization fault; The first-level severe demagnetization fault is a severe demagnetization fault whose current duration is less than a first time threshold; The secondary severe demagnetization fault is a severe demagnetization fault whose current duration is not less than the first time threshold; The current duration is a duration in which the first phase current deviation rate is not less than a second deviation rate threshold.

8. The motor demagnetization detection and processing method according to claim 7, characterized in that: The secondary severe demagnetization fault includes a recoverable demagnetization fault or an irrecoverable demagnetization fault; The recoverable demagnetization fault is a secondary severe demagnetization fault with a current fault number less than a preset number; The irreversible demagnetization fault is a secondary severe demagnetization fault in which the current fault number is not less than a preset number; The current fault number is the number of times the secondary severe demagnetization fault occurs.

9. The motor demagnetization detection and processing method according to claim 8, characterized in that: The current fault number is the number of times the secondary severe demagnetization fault occurs within a preset time period; The preset time period is determined based on the current time corresponding to the measured motor data and a preset duration.

10. The motor demagnetization detection and processing method according to claim 5, characterized in that: After performing demagnetization detection based on the first phase current deviation rate and determining the demagnetization detection result, the motor demagnetization detection processing method further includes: When the demagnetization detection result shows that there is no demagnetization fault, controlling the motor to work based on the demand control strategy; When the demagnetization detection result indicates that a demagnetization fault exists, the motor is controlled to operate based on a protection control strategy.

11. The motor demagnetization detection and processing method according to claim 10, characterized in that: The controlling the motor to work based on the demand control strategy includes: controlling the motor to work based on the demand power; The controlling the motor to work based on the protection control strategy includes: controlling the motor to work based on the protection power; The protection power is less than the required power.

12. The motor demagnetization detection and processing method according to claim 11, characterized in that: The control motor works based on the protection power, including: When the demagnetization detection result indicates that there is a power-limited demagnetization fault, based on a first protection strategy corresponding to the power-limited demagnetization fault, controlling the motor to operate based on a first protection power; When the demagnetization detection result indicates that a severe demagnetization fault exists, based on a second protection strategy corresponding to the severe demagnetization fault, controlling the motor to operate based on a second protection power; The second protection power is smaller than the first protection power.

13. The motor demagnetization detection and processing method according to claim 12, characterized in that: The controlling the motor to operate based on a first protection power based on a first protection strategy corresponding to the power-limited demagnetization fault includes: Based on the mapping relationship between the first phase current deviation rate and the demagnetization limit power, determine a first deviation rate interval, a first calibration time, and a first protection power corresponding to the first phase current deviation rate; Obtaining a first duration of the first phase current deviation rate within the first deviation rate interval; When the first duration is greater than the first rated time, the motor is controlled to operate based on the first protection power.

14. The motor demagnetization detection and processing method according to claim 12, characterized in that: After controlling the motor to operate based on the first protection power according to the first protection strategy corresponding to the power-limited demagnetization fault, the motor demagnetization detection and processing method further includes: Based on the measured motor data, determine the second phase current deviation rate; Determine a second deviation rate interval and a second calibration time corresponding to the second phase current deviation rate based on the second phase current deviation rate and the demagnetization limited power recovery mapping data; Obtaining a second duration of the second phase current deviation rate within the second deviation rate interval; When the second duration is greater than the second rated time, the motor is controlled to operate based on the required power.

15. The motor demagnetization detection and processing method according to claim 10, characterized in that: The controlling the motor to operate based on the demand control strategy includes: controlling the motor to operate based on a first carrier frequency corresponding to a normal working state; The controlling the motor to operate based on the protection control strategy includes: controlling the motor to operate based on a second carrier frequency corresponding to a demagnetization fault state; The second carrier frequency is greater than or equal to the first carrier frequency.

16. The motor demagnetization detection and processing method according to claim 15, characterized in that: The controlling the motor to operate based on a second carrier frequency corresponding to the demagnetization fault state includes: Determining a demagnetization fault level based on the demagnetization detection result; The protection carrier frequency corresponding to the demagnetization fault level is determined as the second carrier frequency corresponding to the demagnetization fault state, and the motor is controlled to operate based on the second carrier frequency corresponding to the demagnetization fault state.

17. A controller comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the motor demagnetization detection and processing method according to any one of claims 1 to 16 is implemented.

18. A motor control system, characterized in that: The invention comprises a motor and the controller according to claim 17, wherein the controller is connected to the motor.

19. A car, characterized in that: Includes the motor control system as described in claim 18.

20. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the motor demagnetization detection and processing method according to any one of claims 1 to 16 is implemented.

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