An overload protection system for motor non-inductive magnetic field oriented control

Abstract

The present invention relates to an overload protection system for non-inductive magnetic field oriented control of a motor. By setting a collection device, a conversion device, an alarm, an actuator and a control module, the conversion device performs Clarke transformation on three-phase current and voltage values ​​to obtain corresponding transformation results, and then obtains the speed and angle of a controlled motor through a non-inductive magnetic field oriented control algorithm, and performs Park transformation based on the obtained angle to obtain a transformation result. The control module obtains the overload multiple by a proportional and integral control algorithm and an overload multiple algorithm, and calls the alarm to execute an alarm when the overload multiple is greater than or equal to a first threshold and less than a second threshold, and calls the actuator to execute shutdown of the controlled motor when the overload multiple is greater than or equal to the second threshold. Compared with the prior art, the calculation complexity is alleviated, the calculation delay is reduced, and the operation safety of the motor is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular to an overload protection system for non-inductive magnetic field oriented control of a motor. Background Art

[0002] In the field of power electronics technology, some inductive field oriented control (FOC) overload protection methods and systems have been proposed. Such technical solutions usually convert the three-phase current of the motor into two-phase current through Clark transformation and Park transformation, and then obtain the direct-axis current and quadrature-axis current through inverse transformation. The power of the motor can be obtained by calculating the sum of the squares of the direct-axis current and the quadrature-axis current. At the same time, the motor output torque can be calculated using the motor speed obtained by the sliding film observer. Finally, the ratio of the motor power to the rated power and the ratio of the motor output torque to the rated torque in the motor design can be used to determine the degree of motor overload and provide real-time warnings.

[0003] However, although the existing non-inductive magnetic field oriented control overload protection method and system can achieve overload protection for the motor to a certain extent, there are still some problems.

[0004] First, this type of technical solution usually requires more complex mathematical calculations when obtaining the output power of the motor, which not only increases the complexity of the algorithm, but also increases the calculation delay and may not be able to respond to the overload condition of the motor in time.

[0005] Secondly, this type of technical solution usually relies on the rated torque in the motor design when judging the degree of motor overload. However, the rated torque of the motor may change under different working conditions, which may lead to inaccurate overload protection.

[0006] Finally, when dealing with motor overload conditions, this type of technical solution usually only provides an early warning, but does not take actual measures to protect the motor and related equipment, making it difficult to effectively prevent damage to the motor. Summary of the invention

[0007] The technical problem to be solved by the present invention is how to overcome the technical defects of the overload protection method and system of non-inductive magnetic field oriented control in the prior art, such as excessive calculation delay, inaccurate overload protection and difficulty in effectively preventing motor damage. In order to overcome the above defects of the prior art, the present invention provides an overload protection system of non-inductive magnetic field oriented control of a motor.

[0008] The present invention provides an overload protection system for motor non-inductive magnetic field oriented control, comprising:

[0009] A collection device, used to obtain the three-phase current value and the three-phase voltage value of the controlled motor in real time;

[0010] a transformation device, configured to perform Clarke transformation on the three-phase current values ​​to obtain a first transformation result, and simultaneously perform Clarke transformation on the three-phase voltage values ​​to obtain a second transformation result, and then obtain the speed and rotation angle of the controlled motor according to the first transformation result and the second transformation result by using an inductive field oriented control algorithm, and perform Park transformation on the first transformation result based on the obtained rotation angle to obtain a third transformation result;

[0011] An alarm device, used for executing an alarm;

[0012] An actuator, used for shutting down the controlled motor;

[0013] a control module, configured to obtain an overload multiple based on the rotation speed, the rotation angle and the third transformation result obtained by the transformation device using a proportional and integral control algorithm and an overload multiple algorithm, and to call the alarm device to perform an alarm when the overload multiple is greater than or equal to a first threshold and less than a second threshold, and to call the actuator to execute shutdown of the controlled motor when the overload multiple is greater than or equal to the second threshold;

[0014] The conversion device is electrically connected to the acquisition device, the control module is electrically connected to the conversion device, and the alarm and the actuator are both electrically connected to the control module.

[0015] The motor non-inductive magnetic field oriented control overload protection system disclosed in the present invention is provided with a collection device, a conversion device, an alarm, an actuator and a control module. The conversion device performs Clark transformation on the three-phase current and voltage values ​​to obtain the corresponding transformation results, and then obtains the speed and angle of the controlled motor through the non-inductive magnetic field oriented control algorithm, and performs Park transformation based on the obtained angle to obtain the transformation result. The control module obtains the overload multiple by the proportional and integral control algorithm and the overload multiple algorithm, and calls the alarm to execute the alarm when the overload multiple is greater than or equal to the first threshold and less than the second threshold, and calls the actuator to execute the shutdown of the controlled motor when the overload multiple is greater than or equal to the second threshold. Since the transformation used is Clark transformation and Park transformation, the algorithm is the proportional and integral control algorithm and the overload multiple algorithm, and thus compared with the prior art, the calculation complexity is alleviated, thereby reducing the calculation delay. In addition, when judging whether the motor is overloaded, it mainly depends on the speed, angle and the overload multiple obtained by the third transformation result obtained by the conversion device, which greatly improves the accuracy of the overload protection, and avoids the inaccurate defect of the overload protection caused by the change of the rated torque. At the same time, since the control module calls the alarm to execute an alarm when the overload multiple is greater than or equal to the first threshold and less than the second threshold, and calls the actuator to shut down the controlled motor when the overload multiple is greater than or equal to the second threshold, when dealing with motor overload conditions, not only an early warning is issued, but also practical measures are taken to protect the motor, thereby effectively preventing damage to the motor.

[0016] In a possible implementation, the acquisition device is a three-way Hall sensor, which can obtain three-phase current and voltage relatively quickly and accurately, further improving the computing efficiency.

[0017] In a possible implementation, the transformation device includes:

[0018] a Clarke transformer for performing a Clarke transform;

[0019] A Park transformer for performing a Park transformation;

[0020] An orientation device, used for obtaining the rotation speed and rotation angle of the controlled motor through a non-inductive magnetic field orientation control algorithm;

[0021] The Clarke converter is electrically connected to the acquisition device, the Park converter is electrically connected to the orientation device and the Clarke converter respectively, and the control module is electrically connected to the orientation device and the Park converter;

[0022] Furthermore, after the acquisition device obtains the three-phase current value and the three-phase voltage value of the controlled motor, the Clarke transform is performed on the three-phase current value through the Clarke converter to obtain the first transform result, and the Clarke transform is performed on the three-phase voltage value to obtain the second transform result. Then, the rotation speed and the angle of rotation of the controlled motor are obtained according to the first transform result and the second transform result by the directional device using the inductive magnetic field directional control algorithm. Finally, the Parker transform is performed on the first transform result based on the angle obtained by the directional device through the Parker converter to obtain the third transform result, thereby ensuring the orderly operation of the algorithm and the transformation, improving the computing efficiency, and reducing the computing complexity.

[0023] In one possible implementation, the Clarke transformer is configured to perform a Clarke transformation in the following form:

[0024] ,

[0025] In the formula,

[0026] ;

[0027] when hour, ;

[0028] when hour, ;

[0029] Represents the three-phase current value obtained by the acquisition device;

[0030] Represents the three-phase voltage value obtained by the acquisition device;

[0031] represents the first transformation result;

[0032] represents the second transformation result;

[0033] The Clarke converter corresponding to this solution can speed up the conversion time, make the conversion reasonable, and capture the conversion result in a shorter time.

[0034] In a possible implementation, the Park transformer is configured to perform the following Park transformation:

[0035] ,

[0036] In the formula,

[0037] represents the rotation angle obtained by the orientation device;

[0038] represents the third transformation result;

[0039] The Park converter corresponding to this scheme uses a mature orthogonal transformation, which only performs an angle rotation on the current vector without changing the norm and thus the current structure, and obtains the transformation result relatively quickly, thereby improving the conversion efficiency.

[0040] In a possible implementation, the control module includes:

[0041] Display, used for users to set target speed, proportional gain and integral gain;

[0042] A proportional and integral controller for executing an operating program of the proportional and integral control algorithm;

[0043] An overload device, used to execute the operating program of the overload multiple algorithm;

[0044] A central processing unit, configured to control the operation of the proportional and integral controller and the overload device according to a target speed, a proportional gain and an integral gain set by a user, and to call the alarm device to perform an alarm when the overload multiple is greater than or equal to the first threshold and less than the second threshold, and to call the actuator to execute shutdown of the controlled motor when the overload multiple is greater than or equal to the second threshold;

[0045] in,

[0046] The display is electrically connected to the orientation device, the central processing unit is electrically connected to the display, and the proportional and integral controller, the overload device, the alarm, and the actuator are all electrically connected to the central processing unit;

[0047] This solution not only ensures the setting of debugging parameters, but also ensures the acquisition of the core item of overload multiples, so that the alarm and actuator can be called more reasonably and quickly, achieving the technical effect of early warning and protecting the motor.

[0048] In a possible implementation, the proportional and integral control algorithm is calculated as follows:

[0049] ,

[0050] In the formula,

[0051] represents the proportional gain;

[0052] represents the integral gain;

[0053] represents the error function;

[0054] The proportional and integral control algorithm corresponding to this solution can improve the processing efficiency of the proportional and integral controller for input, obtain output results more quickly, and thus greatly improve operating efficiency.

[0055] In a possible implementation manner, after the user sets the target speed, the proportional gain and the integral gain on the display, the central processor is configured to perform the following steps:

[0056] A1: Retrieving all rotation speeds obtained by the orientation device during a first period starting from the current moment, and respectively calculating the errors between these rotation speeds and the target rotation speed to obtain a first error distribution;

[0057] A2: calling the proportional and integral controller to obtain a first output result by using the error function formed by the first error distribution;

[0058] A3: Retrieve all the third transformation results output by the Park transformer during a period of a second cycle from this moment on, and calculate the The difference between the current setting value and the current setting value is obtained to obtain the second error distribution, and the third transformation results are calculated respectively. and the first output result to obtain a third error distribution;

[0059] A4: calling the proportional and integral controller to obtain a second output result using the error function formed by the second error distribution, and to obtain a third output result using the error function formed by the third error distribution;

[0060] A5: obtaining output power by using the second output result, the third output result and the third transformation result output by the Park converter at this time through a power algorithm;

[0061] A6: calling the overload device to obtain the overload multiple by using the output power and the rotation speed output by the directional device at this time through the overload multiple algorithm;

[0062] A7: Determine whether the overload multiple is greater than or equal to the first threshold and less than the second threshold;

[0063] If yes, calling the alarm device to execute the alarm;

[0064] If not, proceed to the next step;

[0065] A8: Determine whether the overload multiple is greater than or equal to the second threshold;

[0066] If so, calling the actuator to shut down the controlled motor;

[0067] If not, then go back to step A1;

[0068] This solution not only improves the efficiency and speed in obtaining the overload multiple, but also takes measures to shut down the motor after it is determined that the overload limit has been reached. It can effectively protect the motor and related equipment, prevent damage to the motor, and improve the reliability and safety of the system.

[0069] In a possible implementation manner, the power algorithm in step A5 is calculated as follows:

[0070] ,

[0071] In the formula,

[0072] represents the output power;

[0073] represents the second output result;

[0074] represents the third output result;

[0075] Compared with the prior art which requires complex mathematical operations, this solution has a simpler calculation method, greatly reduces the complexity of the algorithm, reduces calculation delays, and can respond to overload conditions of the controlled motor more promptly.

[0076] In a possible implementation, the overload multiple algorithm is calculated as follows:

[0077] ,

[0078] ,

[0079] In the formula,

[0080] Represents output torque;

[0081] represents the rotation speed output by the directional device;

[0082] Represents the overload multiple;

[0083] Represents the rated torque of the controlled motor;

[0084] Through the above scheme, the output torque is first calculated, and then the overload multiple is obtained using the rated torque in the motor design, thereby improving the accuracy and efficiency of judging the overload degree. Compared with the prior art that relies on the rated torque in the motor design, it is more accurate and can more accurately reflect the working state of the motor, thereby improving the accuracy of overload protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] Figure 1 It is a schematic structural diagram of an overload protection system for motor non-inductive magnetic field oriented control disclosed in an embodiment of the present invention;

[0086] Figure 2 The figure is a flowchart of the operation of the central processing unit disclosed in the embodiment of the present invention. DETAILED DESCRIPTION

[0087] First, those skilled in the art should understand that these implementations are only used to explain the technical principles of the embodiments of the present application, and are not intended to limit the protection scope of the embodiments of the present application. Those skilled in the art can make adjustments to them as needed to adapt to specific application scenarios.

[0088] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "electrical connection" and "electrical connection relationship" should be understood in a broad sense, that is, referring to a connection method with an electrical relationship, for example, it can be a circuit connection through a conductive wire, or it can be an electrical connection through a radio signal channel (channel), or a combination of the two. In addition, "electrical connection" and "electrical connection relationship" can be based on mechanical connection (such as a conductive wire set in a connecting key); it can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0089] In the embodiments of the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0090] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0091] See also Figure 1As shown, the embodiment of the present application discloses an overload protection system for motor non-inductive magnetic field oriented control, Figure 1 It is a structural diagram of the overload protection system, which includes a collection device, a conversion device, an alarm, an actuator and a control module, wherein the conversion device is electrically connected to the collection device, the control module is electrically connected to the conversion device, and the alarm and the actuator are both electrically connected to the control module.

[0092] In the overload protection system, the acquisition device is a three-way Hall sensor, which is used to obtain the three-phase current value and the three-phase voltage value of the controlled motor in real time; the conversion device is used to perform Clarke transformation on the three-phase current value to obtain a first transformation result, and at the same time perform Clarke transformation on the three-phase voltage value to obtain a second transformation result, and then obtain the speed and angle of the controlled motor according to the first transformation result and the second transformation result through the inductive magnetic field oriented control algorithm, and perform Park transformation on the first transformation result based on the obtained angle to obtain a third transformation result; the alarm is used to execute an alarm; the actuator is used to execute the shutdown of the controlled motor; the control module is configured to obtain the overload multiple based on the speed, angle and the third transformation result obtained by the conversion device using a proportional and integral control algorithm and an overload multiple algorithm, and call the alarm to execute an alarm when the overload multiple is greater than or equal to the first threshold and less than the second threshold, and call the actuator to execute the shutdown of the controlled motor when the overload multiple is greater than or equal to the second threshold.

[0093] Please continue to see Figure 1 As shown, in this embodiment, the conversion device includes a Clarke converter, a Park converter and an orientation device, wherein the Clarke converter is electrically connected to the acquisition device, the Park converter is electrically connected to the orientation device and the Clarke converter respectively, and the control module is electrically connected to the orientation device and the Parke converter. In the conversion device, the Clarke converter is used to perform Clarke conversion; the Parke converter is used to perform Parke conversion; and the orientation device is used to obtain the speed and angle of the controlled motor through the inductive magnetic field oriented control algorithm.

[0094] In this embodiment, the conversion device is configured to operate in the following manner: first, the three-phase current value obtained by the acquisition device is Clarke transformed by a Clarke converter to obtain a first transformation result, and the three-phase voltage value is Clarke transformed to obtain a second transformation result. Subsequently, the speed and angle of the controlled motor are obtained according to the first transformation result and the second transformation result by the orientation device using the inductive magnetic field orientation control algorithm. Finally, the first transformation result is Park transformed by a Parke converter based on the angle obtained by the orientation device to obtain a third transformation result. The conversion device in this embodiment ensures the orderly operation of the algorithm and the transformation, improves the operation efficiency, and reduces the operation complexity.

[0095] In this embodiment, the Clarke transformer is configured to perform a Clarke transformation of the following form:

[0096] ,

[0097] In the formula,

[0098] ;

[0099] when hour, ;

[0100] when hour, ;

[0101] Represents the three-phase current value obtained by the acquisition device;

[0102] Represents the three-phase voltage value obtained by the acquisition device;

[0103] represents the first transformation result;

[0104] Represents the second transformation result.

[0105] Based on this transformation, when the Clark converter inputs three-phase current values, the transformation performed is as follows:

[0106] ;

[0107] When the Clark converter inputs a three-phase voltage value, the conversion performed is as follows:

[0108] .

[0109] The Clarke transformer using this transformation type can speed up the transformation time, make the transformation reasonable, and capture the transformation result in a shorter time.

[0110] In this embodiment, the Park transformer is configured to perform a Park transformation of the following form:

[0111] ,

[0112] In the formula,

[0113] represents the rotation angle obtained by the orientation device;

[0114] Represents the third transformation result.

[0115] Please continue to see Figure 1As shown, in this embodiment, the control module includes a display, a proportional and integral controller, an overload device and a central processing unit, wherein the display is electrically connected to the directional device, the central processing unit is electrically connected to the display, and the proportional and integral controller, the overload device, the alarm, and the actuator are all electrically connected to the central processing unit. In the control module, the display is used for the user to set the target speed, proportional gain and integral gain; the proportional and integral controller is used to execute the operating program of the proportional and integral control algorithm; the overload device is used to execute the operating program of the overload multiple algorithm; the central processing unit is used to control the operation of the proportional and integral controller and the overload device according to the target speed, proportional gain and integral gain set by the user, and call the alarm to execute an alarm when the overload multiple is greater than or equal to the first threshold and less than the second threshold, and call the actuator to execute the shutdown of the controlled motor when the overload multiple is greater than or equal to the second threshold.

[0116] In this embodiment, the proportional and integral control algorithm executed by the proportional and integral controller is as follows:

[0117] ,

[0118] In the formula,

[0119] Represents proportional gain, which is a debugging parameter;

[0120] Represents integral gain, which is a debugging parameter;

[0121] Represents the error function.

[0122] Figure 2 For the operation flow chart of the CPU, see Figure 2 As shown in the figure, after the user sets the target speed, proportional gain and integral gain on the display, the central processor is set to perform the following steps:

[0123] A1: retrieve all rotational speeds obtained by the orientation device during a first period starting from the current moment, and calculate the errors between these rotational speeds and the target rotational speed to obtain a first error distribution.

[0124] In principle, the length of the first cycle should be smaller, for example, it can be set to microseconds or less, so as to reduce the computational delay. Let the current time be set to , the length of the first cycle is set to , then the interval corresponding to the first cycle from the current moment is , if in the interval All the rotation speeds obtained by the orientation device are , , …, , and the target speed set by the user is , then the error between these speeds and the target speed is , , …, , is a natural number not less than 1.

[0125] , , …, ,

[0126] So the first error distribution is , , …, .

[0127] A2: Calling a proportional and integral controller to obtain a first output result using an error function formed by a first error distribution.

[0128] The first error distribution can be used , , …, , the error function can be constructed by numerical calculation Of course, it is also possible to directly input the first error distribution into the proportional and integral controller without constructing the error function. The corresponding integral lower limit is The upper limit of the integral is , so the parameters input to the proportional and integral controller by the central processor in this step are , (or , , …, )、 , and , and then the formula for the proportional and integral controller to obtain the first output result is:

[0129] ,

[0130] The proportional and integral controller obtains the first output result Then transmitted to the central processing unit.

[0131] A3: retrieve all the third transformation results output by the Park transformer during the period from this moment to the second cycle, and calculate the The difference between the current setting value and the current setting value is obtained to obtain the second error distribution, and the third transformation results are calculated respectively. The difference between the first output result and the third error distribution is obtained.

[0132] The current setting value is a characteristic constant determined by the safe working current and speed of the controlled motor according to the weight configuration, which can be recorded as . Let this moment be , , and in this embodiment, the length of the second cycle is equal to the length of the first cycle, and then from this moment on, the interval of a second cycle is If the interval All the third transformation results output by the Park transformer are , , …, , then the third transformation results The difference from the current setting value is , , …, , is a natural number not less than 1.

[0133] , , …, ,

[0134] So the third error distribution is , , …, .

[0135] A4: Calling the proportional and integral controller to obtain the second output result using the error function formed by the second error distribution, and to obtain the third output result using the error function formed by the third error distribution.

[0136] The error function constructed using the second error distribution is recorded as , the integral lower limit is The upper limit of the integral is Therefore, the parameters input to the proportional and integral controller by the central processor in this step to obtain the second output result are: , (or , , …, )、 , and , and then the formula for the proportional and integral controller to obtain the second output result is:

[0137] ,

[0138] The proportional and integral controller obtains the second output result Then transmitted to the central processing unit.

[0139] At the same time, the error function constructed using the third error distribution is recorded as In this step, the CPU calls the proportional and integral controller to obtain the third output result. The parameters input to it when running are , (or , , …, )、 ,and , and then the formula for the proportional and integral controller to obtain the third output result is:

[0140] ,

[0141] The proportional and integral controller obtains the third output result Then transmitted to the central processing unit.

[0142] A5: The output power is obtained by using the second output result, the third output result and the third transformation result output by the Park converter at this time through a power algorithm.

[0143] In this embodiment, the power algorithm is calculated as follows:

[0144] ,

[0145] In the formula,

[0146] Represents output power;

[0147] represents the second output result;

[0148] Represents the third output result.

[0149] A6: Call the overload device to obtain the overload multiple by using the output power and the rotation speed output by the directional device at this time through the overload multiple algorithm.

[0150] In this embodiment, the calculation formula of the overload multiple algorithm is as follows:

[0151] ,

[0152] ,

[0153] In the formula,

[0154] Represents output torque;

[0155] Represents the speed of the directional device output;

[0156] Represents the overload multiple;

[0157] Represents the rated torque of the controlled motor.

[0158] A7: Determine whether the overload multiple is greater than or equal to a first threshold and less than a second threshold;

[0159] If yes, call the alarm to execute the alarm, and then return to step A1;

[0160] If not, proceed to the next step.

[0161] In this embodiment, the first threshold is set to 1, and the second threshold is set to 1.5.

[0162] A8: Determine whether the overload multiple is greater than or equal to a second threshold;

[0163] If so, the actuator is called to turn off the controlled motor;

[0164] If not, the process returns to step A1.

[0165] The overload protection system of the motor non-inductive magnetic field oriented control disclosed in the embodiment of the present application obtains the corresponding transformation results by setting the Clarke converter to perform the Clarke transformation and setting the Park transformation to perform the Park transformation, and then obtains the second output result and the third output result based on this through the central processing unit of the control module, and obtains the output power by calculation. Compared with the complex mathematical operations required in the prior art, the calculation method of this embodiment is simpler, greatly reducing the complexity of the algorithm, and reducing the delay of the calculation, so that the overload of the motor can be responded to more promptly. Moreover, after the output torque is calculated by the overload multiple algorithm, the rated torque overload multiple in the motor design is combined with the overload multiple algorithm. Compared with the prior art that relies on the rated torque in the motor design, the judgment method of this embodiment is more accurate, and can more accurately reflect the working state of the motor, thereby improving the accuracy of the overload protection. In addition, the central processing unit set in this embodiment stops the motor after judging that the overload limit is reached. Compared with the prior art that only warns, this embodiment takes practical measures to protect the motor and related equipment, which can more effectively prevent the damage of the motor and improve the reliability and safety of the system.

[0166] In the description of the embodiments of the present application, it should be noted that in the description of the present application, terms such as "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is only for the convenience of description, and does not indicate or imply that the device or component must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present application.

[0167] In the description of the present application, the description with reference to the terms "one embodiment", "some embodiments", "in the present embodiment", "specific example", or "some examples" etc. means that the specific features, mechanisms, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, mechanisms, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0168] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. An overload protection system for motor non-inductive magnetic field oriented control, characterized in that: include: A collection device, used to obtain the three-phase current value and the three-phase voltage value of the controlled motor in real time; a transformation device, configured to perform Clarke transformation on the three-phase current values ​​to obtain a first transformation result, and simultaneously perform Clarke transformation on the three-phase voltage values ​​to obtain a second transformation result, and then obtain the speed and rotation angle of the controlled motor according to the first transformation result and the second transformation result by using an inductive field oriented control algorithm, and perform Park transformation on the first transformation result based on the obtained rotation angle to obtain a third transformation result; An alarm device, used for executing an alarm; An actuator, used for shutting down the controlled motor; a control module, configured to obtain an overload multiple based on the rotation speed, the rotation angle and the third transformation result obtained by the transformation device by using a proportional and integral control algorithm and an overload multiple algorithm, and to call the alarm device to perform an alarm when the overload multiple is greater than or equal to a first threshold and less than a second threshold, and to call the actuator to execute shutdown of the controlled motor when the overload multiple is greater than or equal to the second threshold; The conversion device is electrically connected to the acquisition device, the control module is electrically connected to the conversion device, and the alarm and the actuator are both electrically connected to the control module; The conversion device comprises: a Clarke transformer for performing a Clarke transform; A Park transformer for performing a Park transformation; An orientation device, used for obtaining the rotation speed and rotation angle of the controlled motor through a non-inductive magnetic field orientation control algorithm; The control module comprises: Display, used for users to set target speed, proportional gain and integral gain; A proportional and integral controller for executing an operating program of the proportional and integral control algorithm; An overload device, used to execute the operating program of the overload multiple algorithm; A central processing unit, configured to control the operation of the proportional and integral controller and the overload device according to a target speed, a proportional gain and an integral gain set by a user, and to call the alarm device to perform an alarm when the overload multiple is greater than or equal to the first threshold and less than the second threshold, and to call the actuator to execute shutdown of the controlled motor when the overload multiple is greater than or equal to the second threshold; The Clarke converter is electrically connected to the acquisition device, the Park converter is electrically connected to the orientation device and the Clarke converter respectively, and the control module is electrically connected to the orientation device and the Park converter; The display is electrically connected to the orientation device, the central processing unit is electrically connected to the display, and the proportional and integral controller, the overload device, the alarm, and the actuator are all electrically connected to the central processing unit.

2. The motor non-inductive magnetic field oriented control overload protection system according to claim 1 is characterized in that: The acquisition device is a three-way Hall sensor.

3. The motor non-inductive magnetic field oriented control overload protection system according to claim 2 is characterized in that: The Clarke transformer is arranged to perform a Clarke transform of the form: , In the formula, ； when hour, ; when hour, ; Represents the three-phase current value obtained by the acquisition device; Represents the three-phase voltage value obtained by the acquisition device; represents the first transformation result; Represents the second transformation result.

4. The motor non-inductive magnetic field oriented control overload protection system according to claim 3 is characterized in that: The Park transformer is configured to perform a Park transformation of the form: ， In the formula, represents the rotation angle obtained by the orientation device; Represents the third transformation result.

5. The motor non-inductive magnetic field oriented control overload protection system according to claim 4 is characterized in that: The formula of the proportional and integral control algorithm is as follows: ， In the formula, represents the proportional gain; represents the integral gain; Represents the error function.

6. The motor non-inductive magnetic field oriented control overload protection system according to claim 4 or 5, characterized in that: When the user sets the target speed, the proportional gain and the integral gain on the display, the central processor is configured to perform the following steps: A1: Retrieving all rotation speeds obtained by the orientation device during a first period starting from the current moment, and respectively calculating the errors between these rotation speeds and the target rotation speed to obtain a first error distribution; A2: calling the proportional and integral controller to obtain a first output result by using the error function formed by the first error distribution; A3: Retrieve all the third transformation results output by the Park transformer during a period of a second cycle from this moment on, and calculate the The difference between the current setting value and the current setting value is obtained to obtain the second error distribution, and the third transformation results are calculated respectively. and the first output result to obtain a third error distribution; A4: calling the proportional and integral controller to obtain a second output result using the error function formed by the second error distribution, and to obtain a third output result using the error function formed by the third error distribution; A5: obtaining output power by using the second output result, the third output result and the third transformation result output by the Park converter at this time through a power algorithm; A6； The overload device is called to obtain the overload multiple by using the output power and the rotation speed output by the directional device at this time through the overload multiple algorithm; A7: Determine whether the overload multiple is greater than or equal to the first threshold and less than the second threshold; If yes, calling the alarm device to execute the alarm; If not, proceed to the next step; A8: Determine whether the overload multiple is greater than or equal to the second threshold; If so, calling the actuator to shut down the controlled motor; If not, the process returns to step A1.

7. The motor non-inductive magnetic field oriented control overload protection system according to claim 6, characterized in that: The power algorithm in step A5 is as follows: ， In the formula, represents the output power; represents the second output result; Represents the third output result.

8. The motor non-inductive magnetic field oriented control overload protection system according to claim 7, characterized in that: The formula of the overload multiple algorithm is as follows: ， ， In the formula, Represents output torque; represents the rotation speed output by the directional device; Represents the overload multiple; Represents the rated torque of the controlled motor.

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