A method for power-on self-test of a current hall sensor

Abstract

The application discloses a power-on self-test method of a current Hall sensor, which can detect the abnormality of the Hall sensor through current setting and feedback monitoring, can identify the abnormality of the Hall chip shutdown or crash that cannot be detected by conventional self-test, and improves the accuracy and reliability of detection by comprehensively considering three indexes of current error, current loop output and motor speed. The method is realized by software logic without additional hardware, is low in cost and easy to popularize, can timely find abnormality and stop, avoids the out-of-control or damage of the controller, and is suitable for the fields of electric vehicles and industrial motor control, and significantly improves the safety and reliability of the system.

Description

Technical Field

[0001] This invention relates to the field of sensor detection technology, specifically to a power-on self-test method for a current Hall sensor, which is suitable for detecting the working status of the Hall sensor under complex electromagnetic environments or the influence of peripheral circuits. Background Technology

[0002] Hall effect current sensors are widely used in motor controllers to detect current signals in real time and feed them back to the controller for precise closed-loop current control. Typical self-testing methods for Hall effect sensors include checking parameters such as zero bias, upper and lower limits of the signal, and zero drift to determine if the sensor is functioning correctly. However, in practical applications, due to external circuit faults or electromagnetic interference, the internal chip of the Hall effect sensor may freeze or crash, leading to abnormal output.

[0003] When a Hall sensor chip malfunctions, its output signal typically manifests as a voltage signal corresponding to 0A or a fixed low voltage signal, and this signal no longer changes with the current flowing through the Hall sensor. This abnormal state is difficult to identify using conventional self-test methods because the output signal may still be within the normal range. Because the abnormality of the Hall sensor cannot be detected in time, the controller may malfunction during current control, and in severe cases, may even be damaged.

[0004] In existing technologies, there are few methods for detecting Hall sensor malfunctions, and a simple and effective power-on self-test method is lacking to identify such anomalies before the controller starts operating. Therefore, a new self-test method is urgently needed to improve the reliability of current Hall sensors and ensure the safe and stable operation of the motor control system. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a power-on self-test method for a current Hall sensor, which can effectively detect Hall sensor malfunctions caused by chip crashes or shutdowns, thereby improving the reliability and safety of the control system.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A power-on self-test method for a current Hall sensor, applied in a motor control system, is executed after the controller is powered on and completes a routine self-test, and includes the following steps:

[0008] S1, Set the controller current output upper limit I max Set the upper limit of the current loop output U max Set the upper limit threshold ω for motor speed. max ;

[0009] S2, Set the direct-axis current setpoint Id,ref Set the quadrature axis current setpoint I q,ref =0;

[0010] S3, the controller according to I d,ref and I q,ref =0 output voltage signal, driving motor current;

[0011] S4, sampling motor three-phase current I a I b I c Perform Clarke and Park transformations to obtain the feedback direct-axis current I. d,fb and quadrature axis current I q,fb ;

[0012] S5, Calculation error ΔI d = |I d,ref -I d,fb | Set the allowable error range ò, and monitor the current loop output voltage U and motor speed ω;

[0013] S6, if ΔI d ≤ò, and U≤U max And ω≤ω max If the Hall sensor is functioning normally, proceed to step S4. If ΔI d >ò, or U>U max , or ω > ω max If the Hall sensor malfunctions, a fault report will be sent and the machine will be shut down.

[0014] Preferably, the controller uses a dq coordinate system for current control, where the direct-axis current Id and quadrature-axis current Iq affect the motor's magnetic field and torque, respectively. For a permanent magnet synchronous motor, Iq is proportional to the torque, and Id is controlled to be 0 to reduce losses. This method uses a non-zero Iq as a reference. d,ref and I q,ref =0, so that theoretically the motor does not generate torque and remains stationary.

[0015] Preferably, the Clarke transformation in step S4 converts the three-phase current I... a ,I b ,I c Transformed to I in αβ coordinate system α ,I β :

[0016]

[0017] Preferably, the Park transformation in step S4 converts the current in the αβ coordinate system to I in the dq coordinate system. d ,I q :I d =I α cosθ+Iβ sinθI q =-I α sinθ+I β cosθ, where θ is the electrical angle.

[0018] Preferably, step S5 is set according to the accuracy of the Hall sensor and the system noise level to ensure that normal fluctuations are not misjudged.

[0019] Preferably, steps S4 and S5 involve waiting for more than 1 millisecond based on the system response time to ensure that the system reaches a stable state.

[0020] This invention provides a power-on self-test method for a current Hall sensor. It can detect Hall sensor anomalies through current input and feedback monitoring, identifying Hall chip malfunctions or crashes that conventional self-tests cannot detect. By integrating three indicators—current error, current loop output, and motor speed—it improves the accuracy and reliability of the detection. No additional hardware is required; it is implemented solely through software logic, resulting in low cost and ease of implementation. It can promptly detect anomalies and shut down the system, preventing controller malfunction or damage. It is applicable to fields such as electric vehicles and industrial motor control, significantly improving system safety and reliability. Attached Figure Description

[0021] Figure 1 This is a flowchart of an embodiment of the present invention; Detailed Implementation

[0022] Typical embodiments embodying the features and advantages of this invention will be described in detail in the following description. It should be understood that the invention can have various variations in different embodiments without departing from the scope of the invention, and the descriptions and illustrations herein are for illustrative purposes only and not intended to limit the invention. Those skilled in the art can understand the specific meaning of the terms in this application document according to the specific circumstances.

[0023] Reference Figure 1 As shown, this embodiment of the invention provides a power-on self-test method for a current Hall sensor, applied in a motor control system. The method is executed after the controller is powered on and completes a routine self-test, and includes the following steps:

[0024] S1, Set the controller current output upper limit I max Set the upper limit of the current loop output U max Set the upper limit threshold ω for motor speed. max ;

[0025] S2, Set the direct-axis current setpoint I d,ref Set the quadrature axis current setpoint I q,ref =0;

[0026] S3, the controller according to I d,ref and I q,ref =0 output voltage signal, driving motor current;

[0027] S4, sampling motor three-phase current I a I b I c Perform Clarke and Park transformations to obtain the feedback direct-axis current I. d,fb and quadrature axis current I q,fb ;

[0028] S5, Calculation error ΔI d = |I d,ref -I d,fb | Set the allowable error range ò, and monitor the current loop output voltage U and motor speed ω;

[0029] S6, if ΔI d ≤ò, and U≤U max And ω≤ω max If the Hall sensor is functioning normally, proceed to step S4. If ΔI d >ò, or U>U max , or ω > ω max If the Hall sensor malfunctions, a fault report will be sent and the machine will be shut down.

[0030] In one embodiment, the controller uses a dq coordinate system for current control, where the direct-axis current Id and quadrature-axis current Iq affect the motor's magnetic field and torque, respectively. For a permanent magnet synchronous motor, Iq is proportional to the torque, and Id is controlled to be 0 to reduce losses. Given I... d,ref For 5A, I q,ref The current is set to 0A to ensure that the motor theoretically produces no torque and remains stationary. Therefore, after the controller is powered on, it first performs a routine self-test, including Hall signal zero bias, upper and lower limits, and zero drift detection, to ensure that the static signal is normal.

[0031] Step S4, the Clarke transformation, converts the three-phase current I... a ,I b ,I c Transformed to I in αβ coordinate system α ,I β : Step S4 describes the Park transformation, which converts the current in the αβ coordinate system to I in the dq coordinate system. d ,I q :I d =I α cosθ+I β sinθI q =-I α sinθ+I βcosθ, where θ is the electrical angle. In step S5, ω is set to 0.5A based on the Hall sensor accuracy and system noise level to ensure normal fluctuations are not misinterpreted. Steps S4 and S5 involve waiting at least 10 milliseconds based on the system response time to ensure the system reaches a stable state.

[0032] In the above embodiment, the upper limit threshold of motor speed is set to 10 rpm based on the motor characteristics.

[0033] As demonstrated by the above embodiments, the power-on self-test method for a current Hall sensor provided by the present invention can detect Id when the Hall sensor malfunctions or crashes. fb Don’t follow the ID ref This invention accurately identifies anomalies and implements protective measures by detecting changes in current, abnormal increases in current loop output, or unexpected motor rotation. In summary, the method detects Hall sensor anomalies through current input and feedback monitoring, and can identify Hall chip malfunctions or crashes that conventional self-tests cannot detect. By integrating current error, current loop output, and motor speed, the accuracy and reliability of detection are improved. No additional hardware is required; it is implemented solely through software logic, resulting in low cost and ease of deployment. It can promptly detect anomalies and shut down the system, preventing controller malfunction or damage. It is applicable to fields such as electric vehicles and industrial motor control, significantly improving system safety and reliability.

[0034] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A power-on self-test method for a current Hall sensor, applied in a motor control system, characterized in that, The method is executed after the controller is powered on and completes its routine self-test, and includes the following steps: S1, Set the controller current output upper limit I max Set the upper limit U of the current loop output. max Set the upper limit threshold ω for motor speed. max ; S2, Set the direct-axis current setpoint I d,ref Set the quadrature axis current setpoint I q,ref =0; S3, the controller according to I d,ref and I q,ref =0 output voltage signal, driving motor current; S4, sampling motor three-phase current I a I b I c Perform Clarke and Park transformations to obtain the feedback direct-axis current I. d,fb and quadrature axis current I q,fb ; S5, Calculation error ΔI d = |I d,ref -I d,fb | Set the allowable error range ò, and monitor the current loop output voltage U and motor speed ω; S6, if ΔI d ≤ò, and U≤U max And ω≤ω max If the Hall sensor is functioning normally, proceed to step S4. If ΔI d >ò, or U>U max , or ω > ω max If the Hall sensor malfunctions, a fault will be reported and the machine will be shut down. The controller uses a dq coordinate system for current control, with the direct-axis current I... d and quadrature axis current I q These respectively affect the motor's magnetic field and torque; for permanent magnet synchronous motors, I q Proportional to torque, I d Controlling the value to 0 reduces losses; this method uses a non-zero I value. d,ref and I q,ref =0, so that theoretically the motor does not generate torque and remains stationary; Step S4, the Clarke transformation, converts the three-phase current I... a ,I b ,I c Transformed to I in αβ coordinate system α I β : ； Step S4, the Park transformation, converts the current in the αβ coordinate system to I in the dq coordinate system. d I q :I d =I α cosθ+I β sinθ;Iq=-I α sinθ+I β cosθ, where θ is the electrical angle; The step S5 is set according to the accuracy of the Hall sensor and the system noise level to ensure that normal fluctuations are not misjudged. In steps S4 and S5, the system waits for at least 1 millisecond based on the system response time to ensure that the system reaches a stable state.

Images