CN-116298874-B - Permanent magnet synchronous motor turn-to-turn fault diagnosis method based on high-frequency impedance

CN116298874BCN 116298874 BCN116298874 BCN 116298874BCN-116298874-B

Abstract

The invention discloses a high-frequency impedance-based permanent magnet synchronous motor turn-to-turn fault diagnosis method, which belongs to the technical field of motor control and comprises the steps of injecting three-phase symmetrical high-frequency voltage into a control system, collecting three-phase current, extracting high-frequency component amplitude values in the three-phase current, calculating the three-phase voltage through driving signals of an inverter, extracting high-frequency component amplitude values in the three-phase voltage, calculating three-phase high-frequency impedance by utilizing the high-frequency component amplitude values in the three-phase current and the high-frequency component amplitude values in the three-phase voltage, comparing the three-phase high-frequency impedance to judge whether the turn-to-turn fault of a motor occurs, and diagnosing the turn-to-turn fault of the motor on the premise of not using a hardware structure and detection equipment, so that hardware cost is saved.

Inventors

WANG BO
FENG XIAOBAO
WANG RONGXIN

Assignees

东南大学

Dates

Publication Date: 20260512
Application Date: 20230323

Claims (7)

1. The method for diagnosing the turn-to-turn faults of the permanent magnet synchronous motor based on the high-frequency impedance is characterized by comprising the following steps of: injecting three-phase symmetrical high-frequency voltage into the control system; Collecting three-phase current, and extracting the amplitude of a high-frequency component in the three-phase current; calculating three-phase voltage through a driving signal of an inverter, and extracting high-frequency component amplitude values in the three-phase voltage; calculating three-phase high-frequency impedance by using the high-frequency component amplitude in the three-phase current and the high-frequency component amplitude in the three-phase voltage; Comparing the three-phase high-frequency impedance to judge whether the motor has turn-to-turn faults or not; the step of extracting the amplitude of the high-frequency component in the three-phase current comprises the following steps: S21, setting the frequency of the injected high-frequency voltage as Hz, will ( ) Respectively multiplied by And Can obtain High frequency and direct current components at frequency: Wherein, the Is that The phase currents are selected to be equal to the phase currents, Is that The amplitude of the phase high-frequency current, For the angle of the rotor, Is the initial phase angle of the phase current; s22, filtering the high-frequency component by a low-pass filter, thereby obtaining a direct-current component And ; S23, obtaining root mean square of the direct current component obtained in S22, summing the root mean square results, and multiplying the sum by 2 to obtain The amplitude of the high frequency component of the phase is calculated as: ; The three-phase high-frequency impedance is calculated as: Wherein, the 、、 The three-phase high-frequency impedance is such that, 、、 The amplitudes of high-frequency components in the three-phase voltages are respectively; The step of judging the turn-to-turn fault comprises the following steps: Defining maximum and minimum values of three-phase high-frequency impedance as respectively ; If it is The system judges the normal operation of the permanent magnet synchronous motor if The system judges that the permanent magnet synchronous motor has turn-to-turn faults.
2. The high-frequency impedance-based permanent magnet synchronous motor turn-to-turn fault diagnosis method according to claim 1, wherein the calculation formula of the high-frequency voltage is: Wherein the method comprises the steps of 、、 Respectively, the three-phase high-frequency voltages are injected, In order to inject the magnitude of the high frequency voltage, For injecting the phase angle of the high frequency voltage.
3. The method for diagnosing a turn-to-turn fault of a permanent magnet synchronous motor based on high frequency impedance according to claim 1, wherein the step of calculating the three-phase voltage comprises: s31, calculating the voltage to ground of the midpoint of the three-phase bridge arm of the inverter through the driving signal of the power tube; s32, obtaining the three-phase voltage of the motor through the earth voltage of the midpoint of the three-phase bridge arm of the inverter.
4. The high-frequency impedance-based inter-turn fault diagnosis method for a permanent magnet synchronous motor according to claim 3, wherein in S31, a calculation formula of a voltage to ground at a midpoint of the three-phase bridge arm of the inverter is: Wherein, the 、、 Respectively the voltages to the ground at the midpoints of three-phase bridge arms of the inverter, - Respectively driving signals of three upper tubes of the inverter, - The opposite numbers of the three down tube driving signals of the inverter respectively, Is the DC bus voltage.
5. The high-frequency impedance-based inter-turn fault diagnosis method for the permanent magnet synchronous motor according to claim 3, wherein when the motor is in a healthy state, the three-phase voltage is calculated as follows: Wherein, the 、、 Respectively three-phase voltages.
6. The method for diagnosing a turn-to-turn fault of a permanent magnet synchronous motor based on high frequency impedance according to claim 3, wherein when the motor has a turn-to-turn fault, the three-phase voltage is calculated by the following formula: Wherein, the 、、 The three-phase voltages after the faults are respectively, In order to be a phase resistance, In order to have a short-circuit turns ratio, In order to short-circuit the current, Is the leakage inductance of the motor.
7. A high frequency impedance based permanent magnet synchronous motor turn-to-turn fault diagnostic system performing the method of any of claims 1-6, comprising: the voltage input module is used for injecting three-phase symmetrical high-frequency voltage into the control system; the current component extraction module is used for collecting three-phase current and extracting the amplitude value of a high-frequency component in the three-phase current; the voltage component extraction module is used for calculating three-phase voltages through driving signals of the inverter and extracting high-frequency component amplitude values in the three-phase voltages; The impedance calculating module is used for calculating three-phase high-frequency impedance by utilizing the high-frequency component amplitude value in the three-phase current and the high-frequency component amplitude value in the three-phase voltage; and the fault judging module is used for comparing the three-phase high-frequency impedance and judging whether the motor has turn-to-turn faults or not.

Description

Permanent magnet synchronous motor turn-to-turn fault diagnosis method based on high-frequency impedance Technical Field The invention belongs to the technical field of motor control, and particularly relates to a permanent magnet synchronous motor turn-to-turn fault diagnosis method based on high-frequency impedance. Background The advantages of high efficiency, high power density and the like lead the permanent magnet synchronous motor to be increasingly widely applied, but because of uncontrollable permanent magnet flux linkage, the permanent magnet synchronous motor can generate large fault current when winding turn-to-turn short circuit occurs, and the safe and reliable operation of the motor and a driving system thereof is seriously affected. In order to improve the application of the permanent magnet synchronous motor in high-reliability systems such as aerospace, electric vehicles and the like, the motor needs to be rapidly and reliably detected when the motor has turn-to-turn short circuit fault, further deterioration of the fault is prevented, and a foundation is provided for fault-tolerant operation of the subsequent motor. At present, many students have studied a turn-to-turn short circuit fault diagnosis method. The existing permanent magnet synchronous motor turn-to-turn short circuit fault diagnosis technology is mostly realized by using detection equipment or adding a hardware structure, the method of using the detection equipment often needs motor shutdown for detection, and the addition of the hardware structure can increase the cost of a motor driving system. In order to save hardware cost and realize real-time protection of the stator winding of the permanent magnet synchronous motor, on-line diagnosis of turn-to-turn faults of the permanent magnet synchronous motor is necessary. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide a permanent magnet synchronous motor turn-to-turn fault diagnosis method based on high-frequency impedance, which solves the technical problems in the prior art. The aim of the invention can be achieved by the following technical scheme: a permanent magnet synchronous motor turn-to-turn fault diagnosis method based on high-frequency impedance comprises the following steps: injecting three-phase symmetrical high-frequency voltage into the control system; collecting three-phase current and extracting high-frequency components in the three-phase current; calculating three-phase voltages by driving signals of the inverter, and extracting high-frequency components in the three-phase voltages; Calculating a three-phase high-frequency impedance using the high-frequency component in the three-phase current and the high-frequency component in the three-phase voltage; And comparing the three-phase high-frequency impedance to judge whether the motor has turn-to-turn faults or not. Further, the calculation formula of the high-frequency voltage is as follows: Wherein u ah、ubh、uch is the three-phase high-frequency voltage injected, u h is the amplitude of the high-frequency voltage injected, and θ h is the phase angle of the high-frequency voltage injected. Further, the step of extracting the high frequency component in the three-phase current is: S21, assuming that the frequency of the injected high-frequency voltage is kHz, multiplying i p (p=a, b, c) by sink θ and cosk θ respectively, a high-frequency component and a direct-current component at 2k frequency can be obtained: Wherein I p is p-phase current, I ph is p-phase high-frequency current amplitude, θ is rotor angle, and θ pi is initial phase angle of phase current; s22, filtering the high-frequency component by a low-pass filter, thereby obtaining a direct-current component And S23, obtaining root mean square of the direct current component obtained in the S22, summing the result after root mean square, and multiplying the result by 2 to obtain the amplitude of the p-phase high-frequency component, wherein the calculation formula is as follows: Further, the step of calculating the three-phase voltage includes: s31, calculating the voltage to ground of the midpoint of the three-phase bridge arm of the inverter through the driving signal of the power tube; s32, obtaining the three-phase voltage of the motor through the earth voltage of the midpoint of the three-phase bridge arm of the inverter. Further, in S31, the calculation formula of the voltage to ground at the midpoint of the three-phase bridge arm of the inverter is: wherein u ag、ubg、ucg is the voltage to ground at the middle point of the three-phase bridge arm of the inverter, s 1-s3 is the driving signal of the three upper tubes of the inverter, The reverse numbers of three down tube driving signals of the inverter are respectively, and u dc is the direct current bus voltage. Further, when the motor is in a healthy state, the three-phase voltage is calculated as: Wherein u an、ubn、ucn is three-phase voltage respectivel