A method for improving reliability of double-winding motor control based on current spectrum sensing

Abstract

The application relates to a method for improving the reliability of double-winding motor control based on current spectrum sensing, and the control steps are as follows: a) a main controller receives instructions from a host computer through a bus, controls a main winding, a slave controller receives instructions from the bus, controls a slave winding, and the slave controller receives a main winding current feedback signal; b) the slave controller performs fast Fourier transform (FFT) on the main winding current feedback signal, extracts a fundamental wave, a third harmonic, a fifth harmonic and an even harmonic of the current, judges the running state of the main controller through real-time analysis of the current harmonic in the main winding current feedback signal, and when the current harmonic in the main winding current feedback signal is abnormal and no start instruction is obtained within a set time, the slave controller autonomously starts and controls the slave winding. The method can accurately and timely sense the abnormal condition of the high-voltage side, avoids false detection and missed detection, and greatly improves the reliability of double-winding operation.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of double-winding motor control methods, and more particularly relates to a method for improving the reliability of double-winding motor control based on current spectrum sensing. BACKGROUND

[0002] A double-winding motor is composed of two independent windings, and its main purpose is to improve the reliability of the system by increasing the redundancy of the system. In the case of failure of the main winding control system, the slave winding control system is started to ensure that the system can operate normally in a short time. The most typical application scenario is the power steering device of a vehicle, especially the power system of a large vehicle. In the case of failure of the main control system, the slave control system is started in an emergency to ensure that the power of the vehicle does not fail immediately.

[0003] The current solution is that the main controller and the slave controller simultaneously receive speed and start-stop instructions from the upper computer through the field bus to work. After the main and slave controllers receive the instructions, the results are input to the power inverter circuit through the vector control calculation of the speed loop and the current loop to control the main and slave windings of the motor. The operation instructions of the slave winding are usually given by the upper computer, and some are given by the main controller. The main controller determines whether the slave controller is started and the work share it needs to undertake by analyzing its own working state.

[0004] The biggest problem of the existing system is that it relies too much on the field bus. Whether the instructions given by the upper computer to the slave control or the instructions given by the main controller to the slave controller are sent through the field bus. The field bus is generally CAN or SPI. Once the link of the field bus is interrupted, the slave controller will not be able to obtain the instructions. In the case of failure of the main control system, the slave controller system will not be able to start, and the emergency function will not be achieved. In severe cases, a major safety accident will occur.

[0005] Moreover, the bus itself has a delay, usually 10 milliseconds or even longer. The current control is in the microsecond level. The long delay time of the bus will cause oscillation of the main and slave control systems during switching. In severe cases, it may even be unstable. In the power steering device, the steering wheel will bounce and the steering wheel will shake back and forth. SUMMARY

[0006] To solve the above technical problems, the purpose of the present application is to provide a method for improving the reliability of double-winding motor control based on current spectrum sensing, which can effectively prevent the failure of double-winding motor.

[0007] To achieve the above-mentioned application purpose, the present application adopts the following technical solutions:

[0008] A method for improving the control reliability of a dual-winding motor based on current spectrum sensing includes a main winding, a slave winding, and a master controller and a slave controller for controlling the main winding and the slave winding, respectively. The control steps are as follows:

[0009] a) The main controller receives instructions from the host computer via the bus to control the main winding. The slave controller receives instructions from the host computer or the main controller via the bus to control the slave winding and receives the main winding current feedback signal.

[0010] b) The controller performs a Fast Fourier Transform (FFT) on the main winding current feedback signal to extract the fundamental, third, fifth, and even harmonics of the current. By analyzing the current harmonics in the main winding current feedback signal in real time, the operating status of the main controller is determined. When the current harmonics in the main winding current feedback signal are abnormal, and no start command is received within a set time, the slave controller will start automatically to control the slave winding.

[0011] As a preferred embodiment, the abnormal current harmonic conditions in the main winding current feedback signal include two situations: asymmetrical failure of the bridge arm and symmetrical failure of the bridge arm.

[0012] As a preferred embodiment, under the condition of asymmetrical failure of the bridge arm, the even harmonic value of the current harmonic in the main winding current feedback signal is greater than the calibrated value; and the third harmonic and the multiple harmonics of the third harmonic in the current harmonic in the main winding current feedback signal are both greater than the calibrated value.

[0013] As a preferred embodiment, under the condition of symmetrical failure of the bridge arm, the fifth harmonic and higher harmonics in the current harmonics of the main winding current feedback signal are all greater than the calibration value.

[0014] As a preferred embodiment, the controller also needs to extract the seventh, ninth, eleventh, and thirteenth harmonics of the current.

[0015] As a preferred embodiment, the slave controller includes an autonomous start decision module, a speed control module, a torque control module, and a power inverter module. The autonomous start decision module receives instructions from the bus and the main winding current feedback signal, and the autonomous start module controls the main winding through the speed control module, the torque control module, and the power inverter module.

[0016] As a preferred embodiment, the main controller includes a speed control module, a torque control module, and a power inverter module. The speed control module receives instructions from the bus and controls the main winding through the torque control module and the power inverter module.

[0017] As a preferred embodiment, the speed control module also receives motor position and speed feedback signals, and the torque control module also receives current feedback signals from the corresponding main winding or slave winding.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] This invention incorporates an autonomous start-up decision module for the controller. While the main controller is operating, the slave controller receives commands in real time and simultaneously monitors the current side of the main winding. Through Fast Fourier Transform (FFT), the fundamental, third, fifth, and other higher-order harmonics of the current are extracted. Furthermore, the real-time analysis of the main winding current harmonics determines the operating status of the main controller. If an anomaly occurs and no start-up command is received within a set time, the controller will automatically start. The aforementioned detection criteria can accurately and promptly detect anomalies on the high-voltage side, avoiding false positives and missed negatives, and greatly improving the reliability of dual-winding operation.

[0020] The method of this invention directly obtains abnormal signals from the current side of the main controller in real time, which can greatly reduce the start-up time and thus achieve balanced switching. The steering wheel of the dual-winding motor using this control method has a smooth feel, and the driver may not even feel the switching process. Attached Figure Description

[0021] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute a limitation thereof.

[0022] Fig. 1 This is a schematic diagram of the system structure used in the method of the present invention;

[0023] Fig. 2 This is a schematic flowchart of the method of the present invention;

[0024] Fig. 3 This is a topology diagram of the power inverter circuit used in this invention;

[0025] Fig. 4 This is a diagram showing the measured harmonic data of the master and slave windings under normal operating conditions of the system of the present invention. Detailed Implementation

[0026] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0027] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0028] Furthermore, in the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more, unless explicitly defined otherwise.

[0030] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0031] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0032] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0033] like Figs. 1 to 4 The method for improving the control reliability of a dual-winding motor based on current spectrum sensing, as shown, includes a main winding, a slave winding, and a master controller and a slave controller for controlling the main winding and the slave winding, respectively. The control steps are as follows:

[0034] a) The main controller receives instructions from the host computer via the bus to control the main winding. The slave controller receives instructions from the host computer or the main controller via the bus to control the slave winding and receives the main winding current feedback signal.

[0035] b) The controller performs a Fast Fourier Transform (FFT) on the main winding current feedback signal to extract the fundamental, third, fifth, and even harmonics of the current. By analyzing the current harmonics in the main winding current feedback signal in real time, the operating status of the main controller is determined. When the current harmonics in the main winding current feedback signal are abnormal, and no start command is received within a set time, the slave controller will start automatically to control the slave winding.

[0036] The abnormal current harmonic conditions in the main winding current feedback signal include two scenarios: asymmetrical bridge arm failure and symmetrical bridge arm failure. In the case of asymmetrical bridge arm failure, the even-order harmonics in the main winding current feedback signal are greater than the rated values; furthermore, the third harmonic and its multiples are also greater than the rated values. In the case of symmetrical bridge arm failure, the fifth harmonic and higher-order harmonics in the main winding current feedback signal are all greater than the rated values.

[0037] To improve the accuracy of detection, the controller also needs to extract the seventh, ninth, eleventh, thirteenth, and other harmonics of the current for analysis.

[0038] The slave controller includes an autonomous start decision module, a speed control module, a torque control module, and a power inverter module. The autonomous start decision module receives instructions from the bus and the main winding current feedback signal, and the autonomous start module controls the main winding through the speed control module, the torque control module, and the power inverter module.

[0039] The main controller includes a speed control module, a torque control module, and a power inverter module. The speed control module receives commands from the bus and controls the main winding through the torque control module and the power inverter module. The speed control module also receives motor position and speed feedback signals, and the torque control module also receives current feedback signals from the corresponding main winding or slave winding.

[0040] This invention proposes a reliable method for rapid master-slave controller switching, which changes the existing scheme that relies on instructions. In the event of a CAN bus or SPI bus failure, if the master controller fails, the slave controller will not be able to obtain instructions, thus failing to achieve the emergency function. Furthermore, this invention directly obtains abnormal signals from the current side of the master controller in real time, which can greatly reduce the start-up time and achieve balanced switching of master and slave windings. The steering wheel of the dual-winding motor using this control method has a smooth feel, and the driver may not even feel the switching process.

[0041] Compared to integrating the master and slave controllers into the same control unit, the separate master and slave controllers used in this application, although somewhat redundant and increasing costs slightly, double the reliability of the dual-winding control system, which is precisely the original intention of the dual-winding motor design.

[0042] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0043] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A method for improving the control reliability of a dual-winding motor based on current spectrum sensing, comprising a main winding, a slave winding, and a master controller and a slave controller for controlling the main winding and the slave winding respectively, characterized in that, The control steps are as follows: a) The main controller receives instructions from the host computer via the bus to control the main winding. The slave controller receives instructions from the host computer or the main controller via the bus to control the slave winding and receives the main winding current feedback signal. b) The controller performs a Fast Fourier Transform (FFT) on the main winding current feedback signal to extract the fundamental, third, fifth, and even harmonics of the current. By analyzing the current harmonics in the main winding current feedback signal in real time, the operating status of the main controller is determined. When the current harmonics in the main winding current feedback signal are abnormal and no start command is received within a set time, the slave controller will start automatically to control the slave winding. The abnormal current harmonic conditions in the main winding current feedback signal include two types: asymmetrical failure of the bridge arm and symmetrical failure of the bridge arm. Under the condition of asymmetrical failure of the bridge arm, the even harmonic value of the current harmonic in the main winding current feedback signal is greater than the calibrated value; and the third harmonic and the multiple harmonics of the third harmonic in the current harmonic in the main winding current feedback signal are both greater than the calibrated value. Under the condition of symmetrical failure of the bridge arm, the fifth harmonic and higher harmonics in the current harmonics of the main winding current feedback signal are all greater than the calibration value.

2. The method for improving the control reliability of a dual-winding motor based on current spectrum sensing according to claim 1, characterized in that, The controller also needs to extract the seventh, ninth, eleventh, and thirteenth harmonics of the current.

3. The method for improving the control reliability of a dual-winding motor based on current spectrum sensing according to claim 1, characterized in that, The slave controller includes an autonomous start decision module, a speed control module, a torque control module, and a power inverter module. The autonomous start decision module receives instructions from the bus and the main winding current feedback signal, and the autonomous start module controls the main winding through the speed control module, the torque control module, and the power inverter module.

4. The method for improving the control reliability of a dual-winding motor based on current spectrum sensing according to claim 1, characterized in that, The main controller includes a speed control module, a torque control module, and a power inverter module. The speed control module receives commands from the bus and controls the main winding through the torque control module and the power inverter module.

5. A method for improving the control reliability of a dual-winding motor based on current spectrum sensing according to claim 3 or 4, characterized in that: The speed control module also receives motor position and speed feedback signals, and the torque control module also receives current feedback signals from the corresponding main winding or slave winding.

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