Methods, devices and systems for suppressing electromagnetic noise of air-suspended high-speed motors

Abstract

This disclosure discloses a method, apparatus, and system for suppressing electromagnetic noise in an air-suspended high-speed motor, relating to the field of motors. The method includes: calculating the actual rotor frequency of the air-suspended high-speed motor; determining multiple control points based on the current carrier period of the air-suspended high-speed motor; performing joint calculations at the multiple control points according to the actual rotor frequency to calibrate the rotor position angle; and outputting a control signal to an inverter connected to the air-suspended high-speed motor according to the calibrated rotor position angle, thereby controlling the inverter to output a current signal to the air-suspended high-speed motor. This disclosure can reduce high-frequency current and frequency fluctuations, thereby suppressing high-frequency electromagnetic noise in the unit and improving the stability and dynamic adaptability of the system.

Description

Technical Field

[0001] This disclosure relates to the field of electric motors, and more particularly to a method, apparatus, and system for suppressing electromagnetic noise in an air-suspended high-speed motor. Background Technology

[0002] When an air-suspended rotor rotates at high speed, the air gap between the stator and rotor is typically unevenly suspended, resulting in a non-uniform magnetic field distribution and thus discrete variations in motor load parameters. When using conventional sensorless vector control, as the motor speed increases, the inverter carrier ratio decreases, reducing the number of control operations per fundamental cycle. The larger the lag angle, the less accurate the rotor position estimation, leading to inaccurate magnetic field orientation and causing the actual dq-axis current to deviate from the given value. During high-speed rotation of the air-suspended rotor, the motor current exhibits significant oscillations and instability, with frequency fluctuations exceeding ±20Hz above 560Hz, resulting in severely excessive electromagnetic noise during high-frequency operation of the unit. Summary of the Invention

[0003] One technical problem this disclosure aims to solve is to provide a method, apparatus, and system for suppressing electromagnetic noise in an air-suspended high-speed motor, which can suppress electromagnetic noise.

[0004] According to one aspect of this disclosure, a method for suppressing electromagnetic noise in an air-suspended high-speed motor is proposed, comprising: calculating the actual rotor frequency of the air-suspended high-speed motor; determining multiple control points based on the current carrier period of the air-suspended high-speed motor; performing joint calculations at the multiple control points based on the actual rotor frequency to calibrate the rotor position angle; and outputting a control signal to an inverter connected to the air-suspended high-speed motor based on the calibrated rotor position angle to control the inverter to output a current signal to the air-suspended high-speed motor.

[0005] In some embodiments, the multiple control points include a first control point, a second control point, a third control point, and a fourth control point. The joint calculation at the multiple control points to calibrate the rotor position angle includes: calculating the rotor frequency fluctuation value of the air-suspended high-speed motor at the first control point; if the rotor frequency fluctuation value is greater than a frequency threshold, calculating motor load parameters at the second control point; if the motor load parameters are greater than a load threshold, performing rotor position angle correction at the third control point; and observing the rotor position angle of the air-suspended high-speed motor at the fourth control point to determine whether the rotor position angle has been corrected.

[0006] In some embodiments, calculating motor load parameters includes: controlling the operation of the air-suspended high-speed motor according to a preset trajectory containing multiple acceleration segments, constant speed segments, and deceleration segments; and obtaining motor load parameters based on the current of the air-suspended high-speed motor within a sampling period.

[0007] In some embodiments, controlling the operation of the air-suspended high-speed motor according to a preset trajectory including multiple acceleration segments, constant speed segments, and deceleration segments includes: starting from zero speed, controlling the air-suspended high-speed motor to run at a first acceleration for a first time; controlling the air-suspended high-speed motor to run at a constant speed for a second time; controlling the air-suspended high-speed motor to run at a second acceleration for a third time; controlling the air-suspended high-speed motor to run at a constant speed for a fourth time; controlling the air-suspended high-speed motor to run at a first deceleration for a fifth time, wherein the first acceleration and the first deceleration are equal in magnitude and opposite in direction; controlling the air-suspended high-speed motor to run at a constant speed for a sixth time; controlling the air-suspended high-speed motor to run at a second deceleration for a seventh time, wherein the second acceleration and the second deceleration are equal in magnitude and opposite in direction; and controlling the air-suspended high-speed motor to run at a constant speed for an eighth time, wherein the first time, the third time, the fifth time, and the seventh time are equal.

[0008] In some embodiments, calculating the rotor frequency fluctuation value of the air-suspended high-speed motor includes: determining the rotor frequency fluctuation value based on the difference between the actual rotor frequency and the target rotor frequency.

[0009] In some embodiments, rotor position angle correction includes: estimating the rotor frequency using a full-order sliding diaphragm position observer; obtaining the rotor frequency error based on the difference between the actual rotor frequency and the estimated rotor frequency; obtaining the rotor position angle deviation based on the rotor frequency error; and correcting the rotor position angle based on the rotor position angle deviation.

[0010] In some embodiments, observing the rotor position angle of the air-suspended high-speed motor to determine whether the rotor position angle has been corrected includes: judging whether the rotor position angle of the air-suspended high-speed motor has been corrected based on the sliding surface formed by the stator current error.

[0011] In some embodiments, determining multiple control points based on the current carrier cycle of the air-suspended high-speed motor includes: dividing the motor current carrier cycle into eight time periods, wherein the start time of the first time period and the end time of the fifth time period are respectively taken as the first control point, the start time of the second time period and the end time of the sixth time period are respectively taken as the second control point, the start time of the third time period and the end time of the seventh time period are respectively taken as the third control point, and the start time of the fourth time period and the end time of the eighth time period are respectively taken as the fourth control point.

[0012] In some embodiments, the actual rotor frequency is determined based on the current information on the line between the air-suspended high-speed motor and the inverter.

[0013] According to another aspect of this disclosure, an electromagnetic noise suppression device for an air-suspended high-speed motor is also proposed, comprising: a frequency calculation module configured to calculate the actual rotor frequency of the air-suspended high-speed motor; a control point determination module configured to determine multiple control points based on the current carrier period of the air-suspended high-speed motor; a calibration module configured to perform joint calculations at multiple control points based on the actual rotor frequency to calibrate the rotor position angle; and a control module configured to output a control signal to an inverter connected to the air-suspended high-speed motor based on the calibrated rotor position angle to control the inverter to output a current signal to the air-suspended high-speed motor.

[0014] In some embodiments, the plurality of control points include a first control point, a second control point, a third control point, and a fourth control point, wherein the calibration module is configured to calculate the rotor frequency fluctuation value of the air-suspended high-speed motor at the first control point; if the rotor frequency fluctuation value is greater than a frequency threshold, calculate the motor load parameters at the second control point; if the motor load parameters are greater than a load threshold, perform rotor position angle correction at the third control point; and observe the rotor position angle of the air-suspended high-speed motor at the fourth control point to determine whether the rotor position angle has been corrected.

[0015] In some embodiments, the calibration module is configured to control the operation of the air-suspended high-speed motor according to a preset trajectory including multiple acceleration segments, constant speed segments, and deceleration segments; and to obtain motor load parameters based on the current of the air-suspended high-speed motor during the sampling period.

[0016] In some embodiments, the calibration module is configured to start from zero speed and control the air-suspended high-speed motor to run at a first acceleration for a first time, at a constant speed for a second time, at a second acceleration for a third time, at a constant speed for a fourth time, at a first deceleration for a fifth time, at a constant speed for a sixth time, at a second deceleration for a seventh time, and at a constant speed for an eighth time, wherein the first acceleration and the first deceleration are equal in magnitude and opposite in direction, the second acceleration and the second deceleration are equal in magnitude and opposite in direction, and the first time, the third time, the fifth time and the seventh time are equal.

[0017] In some embodiments, the calibration module is configured to determine the rotor frequency fluctuation value based on the difference between the actual rotor frequency and the target rotor frequency.

[0018] In some embodiments, the calibration module is configured to estimate the rotor frequency using a full-order sliding diaphragm position observer; obtain the rotor frequency error based on the difference between the actual rotor frequency and the estimated rotor frequency; obtain the rotor position angle deviation based on the rotor frequency error; and correct the rotor position angle based on the rotor position angle deviation.

[0019] In some embodiments, the calibration module is configured to determine whether the rotor position angle of the air-suspended high-speed motor has been corrected based on the sliding surface formed by the stator current error.

[0020] In some embodiments, the control point determination module is configured to divide the motor current carrier cycle into eight time periods, wherein the start time of the first time period and the end time of the fifth time period are respectively used as the first control point, the start time of the second time period and the end time of the sixth time period are respectively used as the second control point, the start time of the third time period and the end time of the seventh time period are respectively used as the third control point, and the start time of the fourth time period and the end time of the eighth time period are respectively used as the fourth control point.

[0021] In some embodiments, the actual rotor frequency is determined based on the current information on the line between the air-suspended high-speed motor and the inverter.

[0022] According to another aspect of this disclosure, an electromagnetic noise suppression device for an air-suspended high-speed motor is also proposed, comprising: a memory; and a processor coupled to the memory, the processor being configured to execute the electromagnetic noise suppression method for the air-suspended high-speed motor as described above based on instructions stored in the memory.

[0023] According to another aspect of this disclosure, an electromagnetic noise suppression system for an air-suspended high-speed motor is also proposed, comprising: the aforementioned electromagnetic noise suppression device for an air-suspended high-speed motor; an inverter configured to output AC power to the air-suspended high-speed motor according to a control signal output by the electromagnetic noise suppression device; and a sampling and calculation circuit configured to sample the current information of the air-suspended high-speed motor and determine the rotor frequency of the air-suspended high-speed motor based on the current information.

[0024] According to another aspect of this disclosure, a non-transient computer-readable storage medium is also proposed, on which computer program instructions are stored, which, when executed by a processor, implement the above-described method for suppressing electromagnetic noise of an air-suspended high-speed motor.

[0025] In this embodiment of the disclosure, the rotor position angle is calibrated by joint calculation of multiple control points within the current carrier cycle based on the actual rotor frequency, and the current output of the inverter is controlled to reduce high-frequency current and frequency fluctuations, thereby suppressing high-frequency electromagnetic noise of the unit and improving the stability and dynamic adaptability of the system.

[0026] Other features and advantages of this disclosure will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0027] The accompanying drawings, which form part of this specification, illustrate embodiments of this disclosure and, together with the specification, serve to explain the principles of this disclosure.

[0028] This disclosure will become clearer with reference to the accompanying drawings and the following detailed description, wherein:

[0029] Figure 1 This is a flowchart illustrating some embodiments of the electromagnetic noise suppression method for air-suspended high-speed motors disclosed herein.

[0030] Figure 2 This is a schematic diagram of the structure of some embodiments of the electromagnetic noise suppression system for air-suspended high-speed motors disclosed herein;

[0031] Figure 3 This is a schematic diagram of some embodiments of the control points within the current carrier cycle of this disclosure;

[0032] Figure 4 This is a flowchart illustrating some other embodiments of the electromagnetic noise suppression method for air-suspended high-speed motors disclosed herein;

[0033] Figure 5 This is a schematic diagram of some embodiments of the motor motion trajectory during the calculation of motor load parameters in this disclosure;

[0034] Figure 6 This is a flowchart illustrating some other embodiments of the electromagnetic noise suppression method for air-suspended high-speed motors disclosed herein;

[0035] Figure 7 This is a schematic diagram of the high-frequency 560Hz calibration rotor position angle disclosed herein;

[0036] Figure 8 These are schematic diagrams illustrating the structure of some embodiments of the electromagnetic noise suppression device for air-suspended high-speed motors disclosed herein; and

[0037] Figure 9 The following are schematic diagrams of other embodiments of the electromagnetic noise suppression device for air-suspended high-speed motors disclosed herein. Detailed Implementation

[0038] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present disclosure.

[0039] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0040] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this disclosure or its application or use.

[0041] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0042] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0043] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0044] To make the objectives, technical solutions, and advantages of this disclosure clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0045] Figure 1 This is a schematic diagram of some embodiments of the electromagnetic noise suppression method for air-suspended high-speed motors disclosed herein. These embodiments are executed by a controller, for example, by a DSP (Digital Signal Processing).

[0046] In step 110, the actual rotor frequency of the air-suspended high-speed motor is calculated.

[0047] In some embodiments, the actual rotor frequency is determined based on the current information on the line between the air-suspended high-speed motor and the inverter.

[0048] like Figure 2 As shown, inverter 1 outputs three-phase current to motor M, and sampling and calculation circuit 2 collects the current on any one phase of the three-phase circuit. After processing by differential amplifier circuit, the actual rotor frequency is obtained.

[0049] The motor M is, for example, HPMSM (Hybrid Excitation Permanent Magnet Synchronous Motor) or HSPMSM (High Speed ​​Permanent Magnet Synchronous Motor).

[0050] Those skilled in the art should understand that obtaining the rotor frequency is equivalent to obtaining the rotor angular velocity, rotor position angle, etc. Where w is the rotor angular velocity, f is the rotor frequency, and θ is the rotor position angle.

[0051] In step 120, multiple control points are determined based on the current carrier cycle of the air-suspended high-speed motor.

[0052] In some embodiments, the plurality of control points include a first control point, a second control point, a third control point, and a fourth control point.

[0053] In some embodiments, the motor current carrier cycle is divided into eight time periods, for example, into eight equal time periods. The start time of the first time period and the end time of the fifth time period are respectively used as the first control point, the start time of the second time period and the end time of the sixth time period are respectively used as the second control point, the start time of the third time period and the end time of the seventh time period are respectively used as the third control point, and the start time of the fourth time period and the end time of the eighth time period are respectively used as the fourth control point.

[0054] For example, such as Figure 3 As shown, the sampling calculation circuit 2 can collect frequency reference points. The first control point A is the carrier point with a carrier ratio of 0% in the first half of the motor current carrier cycle. The second control point B is the carrier point with a carrier ratio of 25% in the first half of the motor current carrier cycle. The third control point C is the carrier point with a carrier ratio of 50% in the first half of the motor current carrier cycle. The fourth control point D is the carrier point with a carrier ratio of 75% in the first half of the motor current carrier cycle. The first control point A1 is the carrier point with a carrier ratio of 75% in the second half of the motor current carrier cycle. The second control point B1 is the carrier point with a carrier ratio of 50% in the second half of the motor current carrier cycle. The third control point C1 is the carrier point with a carrier ratio of 25% in the second half of the motor current carrier cycle. The fourth control point D1 is the carrier point with a carrier ratio of 0% in the half-cycle of the motor current carrier cycle.

[0055] In step 130, based on the actual rotor frequency, a joint calculation is performed at multiple control points to calibrate the rotor position angle.

[0056] In some embodiments, the rotor frequency fluctuation value of the air-suspended high-speed motor is calculated at a first control point; if the rotor frequency fluctuation value is greater than a frequency threshold, the motor load parameters are calculated at a second control point; if the motor load parameters are greater than a load threshold, rotor position angle correction is performed at a third control point; and the rotor position angle of the air-suspended high-speed motor is observed at a fourth control point to determine whether the rotor position angle has been corrected.

[0057] In step 140, based on the calibrated rotor position angle, a control signal is output to the inverter connected to the air-suspended high-speed motor to control the inverter to output a current signal to the air-suspended high-speed motor.

[0058] For example, such as Figure 1 As shown, the DSP outputs a corresponding PWM wave to the switching transistor in the inverter based on the calibrated rotor position angle. By switching the transistor on and off, the current output by the inverter satisfies the rotor position angle of the motor.

[0059] In the above embodiments, the rotor position angle is calibrated by joint calculation of multiple control points within the current carrier cycle based on the actual rotor frequency, and the current output of the inverter is controlled to reduce high-frequency current and frequency fluctuations, thereby suppressing high-frequency electromagnetic noise of the unit and improving the stability and dynamic adaptability of the system.

[0060] Figure 4 This is a flowchart illustrating some other embodiments of the electromagnetic noise suppression method for the air-suspended high-speed motor disclosed herein. The air-suspended high-speed motor operates in the 200–1000 Hz frequency range, specifically, for example, the 500–1000 Hz high-frequency range.

[0061] In step 410, the rotor frequency fluctuation value is calculated at the first control point.

[0062] In some embodiments, the rotor frequency fluctuation value is determined based on the difference between the actual rotor frequency and the target rotor frequency.

[0063] For example, if the actual rotor frequency is 1000Hz and the target rotor frequency is 998Hz, then the rotor frequency fluctuation value is 2Hz.

[0064] In step 420, it is determined whether the rotor frequency fluctuation value is greater than the frequency threshold. If so, step 430 is executed; otherwise, the control is terminated.

[0065] In some embodiments, the frequency threshold is 2Hz. If the rotor frequency fluctuation value is greater than 2Hz, it indicates that the frequency fluctuation is large, and further noise assessment is required. If the rotor frequency fluctuation value is less than or equal to 2Hz, the switching of the inverter's transistors is controlled using existing control algorithms.

[0066] In step 430, the motor load parameters are calculated at the second control point.

[0067] In some embodiments, the operation of the air-suspended high-speed motor is controlled according to a preset trajectory that includes multiple acceleration segments, constant speed segments, and deceleration segments; and the motor load parameters are obtained according to the current of the air-suspended high-speed motor during the sampling period.

[0068] For example, such as Figure 5As shown, starting from zero speed, the air-suspended high-speed motor is controlled to run at a first acceleration w1 for a first time T1; the air-suspended high-speed motor is controlled to run at a constant speed for a second time t0; the air-suspended high-speed motor is controlled to run at a second acceleration w2 for a third time T2; the air-suspended high-speed motor is controlled to run at a constant speed for a fourth time t0; the air-suspended high-speed motor is controlled to run at a first deceleration w3 for a fifth time T3, wherein the first acceleration w1 and the first deceleration w1 are equal in magnitude and opposite in direction; the air-suspended high-speed motor is controlled to run at a constant speed for a sixth time t0; the air-suspended high-speed motor is controlled to run at a second deceleration w2 for a seventh time T4, wherein the second acceleration w2 and the second deceleration w2 are equal in magnitude and opposite in direction; and the air-suspended high-speed motor is controlled to run at a constant speed for an eighth time t0, wherein the first time T1, the third time T2, the fifth time T3, and the seventh time T4 are equal, the second time, the fourth time, the sixth time, and the eighth time are equal, and the first acceleration w1 and the second acceleration w2 are different. The first acceleration, the second acceleration, the third acceleration, the fourth acceleration, and the corresponding time information can be set according to the actual situation.

[0069] Within a sampling period, using the formula Calculate the motor load parameter J, where K t T is the motor torque constant. c Where N is the sampling period, N is the number of sampling points, and n0 is the first sampling point.

[0070] i qxT (n) represents the d-axis current component in the nth dq stationary coordinate system, i qyT (n) represents the q-axis current component in the nth dq stationary coordinate system.

[0071] In step 440, it is determined whether the motor load parameter is greater than the load threshold. If so, proceed to step 450; otherwise, proceed to step 460.

[0072] In some embodiments, if the motor load parameters are greater than the load threshold, it indicates that the motor has high-frequency electromagnetic noise.

[0073] In step 450, rotor position angle correction is performed at the third control point.

[0074] In some embodiments, the rotor frequency is estimated using a full-order sliding diaphragm position observer; the rotor frequency error is obtained based on the difference between the actual rotor frequency and the estimated rotor frequency; the rotor position angle deviation is obtained based on the rotor frequency error; and the rotor position angle is corrected based on the rotor position angle deviation. Δf is the rotor frequency error, and Δθ is the rotor position angle deviation.

[0075] In some embodiments, such as Figure 6 Target excitation current With the actual d-axis current i d The difference is controlled by a PI controller to obtain the d-axis voltage value. Target torque current With the actual q-axis current i q The difference is controlled by a PI controller to obtain the q-axis voltage value. and The voltage U in the αβ coordinate system is obtained by inverse Park transform. α and U β U α and U β The input is fed to the SVPWM (Space Vector Pulse Width Modulation) module, which outputs PWM waves to control the on / off state of the inverter's six switching transistors. The inverter outputs three-phase current to the motor IPMSM, where the three-phase current i a i b i c After Clarke transformation, the output current i in the αβ coordinate system is obtained. α and i β i α and i β After the Park transformation, the actual d-axis current i is obtained. d and actual q-axis current i q .

[0076] The inputs to the full-order slug position observer SMO are the voltage U in the αβ coordinate system. α and U β and the previously estimated rotor angular velocity The SMO output is the back electromotive force error value in the stationary coordinate system. and and observed current and Current i in the αβ coordinate system α and i β Respectively with the observed current and After performing the difference operation, the result is input to the sliding surface. and After processing by the phase-locked loop (PLL), the observed rotor position angle is output. and rotor angular velocity Target rotor angular velocity w and observed rotor angular velocity The difference is used to obtain the target torque current through PI control.

[0077] In step 460, the rotor position angle of the air-suspended high-speed motor is observed at the fourth control point to determine whether the rotor position angle has been corrected.

[0078] In some embodiments, the rotor position angle of the air-suspended high-speed motor is determined based on the sliding surface formed by the stator current error; if the rotor position angle is corrected, the rotor position angle is maintained; otherwise, the rotor frequency fluctuation value of the air-suspended high-speed motor is recalculated at the first control point.

[0079] By using current and back electromotive force as observed variables, the electric angular velocity of the motor is calculated to replace the actual electric angular velocity of the motor, thus obtaining the observation equation. Stator current sampling and measurement is a crucial part of motor controllers, offering high measurement accuracy and making it well-suited as calibration feedback for the state observer. Based on the observation matrix above, a sliding surface formed by the stator current error is used as the calibration term (error compensator). The system state equation then becomes: Sliding surface formed by current error Since the fluctuation of rotational speed is relatively low compared to the electromagnetic time coefficient of the motor, it can be approximated as constant, thus yielding the error equation between the observed back EMF and the actual back EMF: in and These represent the back electromotive force (EMF) error values ​​in the stationary coordinate system. When the system enters the sliding mode surface, the observed current is very close to the actual current, and the current observation error is 0. Based on the state observation matrix and the error value of the back EMF, the error equation for the back EMF is obtained as follows: As can be seen from the above expression, the back electromotive force (EMF) already includes the prediction and calibration stages of the Kalman filter, so no additional filtering is needed on the observed back EMF, thus eliminating the need for phase compensation. Figure 7 As shown, θ e The original rotor position angle, To calibrate the rotor position angle.

[0080] In the above embodiments, based on the characteristics of the discrete changes in motor parameters caused by the uneven air gap suspension when the air-suspended rotor rotates at high speed in the high-frequency range, the rotor frequency fluctuation value of the air-suspended high-speed motor is calculated at the first control point, the motor load parameters are calculated at the second control point, the rotor position angle is corrected at the third control point, and the rotor position angle of the air-suspended high-speed motor is observed at the fourth control point. This controls the compressor current in the high-frequency range to be stable and oscillating, so that the system operates in the optimal underdamped state. Under heavy load, there will be no overcurrent or loss of synchronism problems, thereby improving the stability of the system and the adaptability of motor parameters.

[0081] Actual tests have proven that this disclosure can suppress high-frequency fluctuations above 560Hz to ±2Hz, with a maximum pipeline vibration amplitude of 1200μm and noise less than 85dB, all of which are less than the standard requirements, thus solving the problems of vibration stress, strain and noise in the high-frequency band.

[0082] Figure 8 This is a schematic diagram of the structure of some embodiments of the electromagnetic noise suppression device for air-suspended high-speed motors disclosed herein. The device includes a frequency calculation module 810, a control point determination module 820, a calibration module 830, and a control module 840.

[0083] The frequency calculation module 810 is configured to calculate the actual rotor frequency of the air-suspended high-speed motor.

[0084] In some embodiments, the actual rotor frequency is determined based on the current information on the line between the air-suspended high-speed motor and the inverter.

[0085] The control point determination module 820 is configured to determine multiple control points based on the current carrier cycle of the air-suspended high-speed motor.

[0086] In some embodiments, the plurality of control points include a first control point, a second control point, a third control point, and a fourth control point.

[0087] In some embodiments, the motor current carrier cycle is divided into eight time periods, for example, into eight equal time periods. The start time of the first time period and the end time of the fifth time period are respectively used as the first control point, the start time of the second time period and the end time of the sixth time period are respectively used as the second control point, the start time of the third time period and the end time of the seventh time period are respectively used as the third control point, and the start time of the fourth time period and the end time of the eighth time period are respectively used as the fourth control point.

[0088] The calibration module 830 is configured to perform joint calculations at multiple control points based on the actual rotor frequency to calibrate the rotor position angle.

[0089] In some embodiments, the rotor frequency fluctuation value of the air-suspended high-speed motor is calculated at a first control point; if the rotor frequency fluctuation value is greater than a frequency threshold, the motor load parameters are calculated at a second control point; if the motor load parameters are greater than a load threshold, rotor position angle correction is performed at a third control point; and the rotor position angle of the air-suspended high-speed motor is observed at a fourth control point to determine whether the rotor position angle has been corrected.

[0090] In some embodiments, the rotor frequency fluctuation value is determined based on the difference between the actual rotor frequency and the target rotor frequency. For example, if the frequency threshold is 2Hz, and the rotor frequency fluctuation value is greater than 2Hz, it indicates that the frequency fluctuation is large, and further noise assessment is required. If the rotor frequency fluctuation value is less than or equal to 2Hz, the switching of the inverter's transistors is controlled using existing control algorithms.

[0091] In some embodiments, the operation of the air-suspended high-speed motor is controlled according to a preset trajectory that includes multiple acceleration segments, constant speed segments, and deceleration segments; and the motor load parameters are obtained according to the current of the air-suspended high-speed motor during the sampling period.

[0092] For example, such as Figure 5 As shown, starting from zero speed, the air-suspended high-speed motor is controlled to run at a first acceleration w1 for a first time T1; the air-suspended high-speed motor is controlled to run at a constant speed for a second time t0; the air-suspended high-speed motor is controlled to run at a second acceleration w2 for a third time T2; the air-suspended high-speed motor is controlled to run at a constant speed for a fourth time t0; the air-suspended high-speed motor is controlled to run at a first deceleration w3 for a fifth time T3, wherein the first acceleration w1 and the first deceleration w1 are equal in magnitude and opposite in direction; the air-suspended high-speed motor is controlled to run at a constant speed for a sixth time t0; the air-suspended high-speed motor is controlled to run at a second deceleration w2 for a seventh time T4, wherein the second acceleration w2 and the second deceleration w2 are equal in magnitude and opposite in direction; and the air-suspended high-speed motor is controlled to run at a constant speed for an eighth time t0, wherein the first time T1, the third time T2, the fifth time T3, and the seventh time T4 are equal, the second time, the fourth time, the sixth time, and the eighth time are equal, and the first acceleration w1 and the second acceleration w2 are different. The first acceleration, the second acceleration, the third acceleration, the fourth acceleration, and the corresponding time information can be set according to the actual situation.

[0093] In some embodiments, if the motor load parameters are greater than the load threshold, it indicates that the motor has high-frequency electromagnetic noise.

[0094] In some embodiments, the rotor frequency is estimated using a full-order sliding diaphragm position observer; the rotor frequency error is obtained based on the difference between the actual rotor frequency and the estimated rotor frequency; the rotor position angle deviation is obtained based on the rotor frequency error; and the rotor position angle is corrected based on the rotor position angle deviation.

[0095] In some embodiments, the rotor position angle of the air-suspended high-speed motor is determined based on the sliding surface formed by the stator current error.

[0096] The control module 840 is configured to output a control signal to the inverter connected to the air-suspended high-speed motor based on the calibrated rotor position angle, so as to control the inverter to output a current signal to the air-suspended high-speed motor.

[0097] In the above embodiments, the rotor position angle is calibrated by joint calculation of multiple control points within the current carrier cycle based on the actual rotor frequency, which solves the problem of motor current oscillation instability caused by eccentric air gap, thereby suppressing high-frequency electromagnetic noise of the unit and improving the stability and dynamic adaptability of the system.

[0098] Figure 9 This is a schematic diagram of the structure of some other embodiments of the electromagnetic noise suppression device for air-suspended high-speed motors disclosed herein. The device 900 includes a memory 910 and a processor 920. The memory 910 can be a disk, flash memory, or any other non-volatile storage medium. The memory 910 is used to store the instructions in the above embodiments. The processor 920 is coupled to the memory 910 and can be implemented as one or more integrated circuits, such as a microprocessor or microcontroller. The processor 920 is used to execute the instructions stored in the memory.

[0099] In some embodiments, the processor 920 is coupled to the memory 910 via a BUS bus 930. The device 900 can also be connected to an external storage device 950 via a storage interface 940 to access external data, and can also be connected to a network or another computer system (not shown) via a network interface 960, which will not be described in detail here.

[0100] In this embodiment, by storing data instructions in a memory and then processing the instructions by a processor, the problem of unstable motor current oscillation caused by the eccentric air gap when the air-suspended rotor rotates at high frequency and high speed can be solved, thereby solving the problems of vibration stress, strain and noise in the high-frequency band.

[0101] In other embodiments of this disclosure, such as Figure 2 As shown, a protection system for electromagnetic noise suppression of an air-suspended high-speed motor includes an inverter 1, a sampling and calculation circuit 2, and an electromagnetic noise suppression device 3 for an air-suspended high-speed motor in the above embodiment. The electromagnetic noise suppression device 3 for an air-suspended high-speed motor is a controller, specifically, for example, a DSP.

[0102] Inverter 2 is configured to output AC power to the air-suspended high-speed motor M based on the control signal output by the electromagnetic noise suppression device 3 of the air-suspended high-speed motor. Sampling and calculation circuit 2 is configured to sample the current information of the air-suspended high-speed motor and determine the rotor frequency of the air-suspended high-speed motor based on the current information.

[0103] The sampling and calculation circuit 2 can collect the current of any phase. For example, it can collect the current in phase V through resistor R0, convert it into a voltage signal, and then pass it through a differential circuit composed of multiple amplifiers to calculate the rotor frequency or rotor angular velocity of the air-suspended high-speed motor.

[0104] In other embodiments, a computer-readable storage medium stores computer program instructions that, when executed by a processor, implement the steps of the methods described above. Those skilled in the art will understand that embodiments of this disclosure can be provided as methods, apparatus, or computer program products. Therefore, this disclosure can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this disclosure can take the form of a computer program product embodied on one or more computer-usable non-transitory storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0105] This disclosure is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create a machine for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0106] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0107] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0108] This concludes the detailed description of the present disclosure. To avoid obscuring the concept of the disclosure, some details known in the art have not been described. Those skilled in the art will fully understand how to implement the technical solutions disclosed herein based on the above description.

[0109] While specific embodiments of this disclosure have been described in detail by way of example, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this disclosure. The scope of this disclosure is defined by the appended claims.

Claims

1. A method for electromagnetic noise suppression of an air-suspended high-speed motor, comprising: calculating an actual rotor frequency of the air-suspended high-speed motor; determining a plurality of control points based on a current carrier period of the air-suspended high-speed motor, including: dividing the current carrier period into eight time segments, wherein a starting time of a first time segment and an ending time of a fifth time segment are taken as a first control point, a starting time of a second time segment and an ending time of a sixth time segment are taken as a second control point, a starting time of a third time segment and an ending time of a seventh time segment are taken as a third control point, and a starting time of a fourth time segment and an ending time of an eighth time segment are taken as a fourth control point; jointly calculating at the plurality of control points according to the actual rotor frequency to calibrate a rotor position angle, including: calculating a rotor frequency fluctuation value of the air-suspended high-speed motor at the first control point, calculating a motor load parameter at the second control point if the rotor frequency fluctuation value is greater than a frequency threshold, correcting the rotor position angle at the third control point if the motor load parameter is greater than a load threshold, and observing the rotor position angle of the air-suspended high-speed motor at the fourth control point to determine whether the rotor position angle is corrected; and outputting a control signal to an inverter connected to the air-suspended high-speed motor according to the calibrated rotor position angle to control the inverter to output a current signal to the air-suspended high-speed motor.

2. The electromagnetic noise suppression method for gas suspension high-speed electric machines according to claim 1, wherein, The calculating of the motor load parameter includes: controlling operation of the air-suspended high-speed motor according to a preset trajectory including a plurality of acceleration segments, constant speed segments, and deceleration segments; and obtaining the motor load parameter according to a current of the air-suspended high-speed motor within a sampling period.

3. The electromagnetic noise suppression method for gas suspension high-speed electric machines according to claim 2, wherein, The controlling of the operation of the air-suspended high-speed motor according to the preset trajectory including the plurality of acceleration segments, constant speed segments, and deceleration segments includes: starting with zero speed, controlling the air-suspended high-speed motor to operate at a first acceleration for a first time; controlling the air-suspended high-speed motor to operate at a constant speed for a second time; controlling the air-suspended high-speed motor to operate at a second acceleration for a third time; controlling the air-suspended high-speed motor to operate at a constant speed for a fourth time; controlling the air-suspended high-speed motor to operate at a first deceleration for a fifth time, wherein the first acceleration and the first deceleration are equal in magnitude and opposite in direction; controlling the air-suspended high-speed motor to operate at a constant speed for a sixth time; controlling the air-suspended high-speed motor to operate at a second deceleration for a seventh time, wherein the second acceleration and the second deceleration are equal in magnitude and opposite in direction; and controlling the air-suspended high-speed motor to operate at a constant speed for an eighth time, wherein the first time, the third time, the fifth time, and the seventh time are equal.

4. The electromagnetic noise suppression method for gas suspension high-speed electric machines according to claim 1, wherein, The calculating of the rotor frequency fluctuation value of the air-suspended high-speed motor includes: determining the rotor frequency fluctuation value according to a difference between the actual rotor frequency and a target rotor frequency.

5. The electromagnetic noise suppression method for gas suspension high-speed electrical machines according to claim 1, wherein, The correcting of the rotor position angle includes: estimating a rotor frequency using a full-order sliding mode position observer; obtaining a rotor frequency error according to a difference between the actual rotor frequency and the estimated rotor frequency; and obtain a rotor position angle deviation based on the rotor frequency error; and correct the rotor position angle according to the rotor position angle deviation.

6. The electromagnetic noise suppression method for gas suspension high-speed electrical machines according to claim 1, wherein, observing the rotor position angle of the gas-suspended high-speed motor to determine whether the rotor position angle is corrected comprises: determining whether the rotor position angle of the gas-suspended high-speed motor is corrected according to a sliding mode surface formed by the stator current error.

7. The electromagnetic noise suppression method for gas suspension high-speed electrical machines according to any of claims 1 to 6, wherein, The actual rotor frequency is determined according to current information on a line between the gas-suspended high-speed motor and the inverter.

8. A gas-suspended high-speed motor electromagnetic noise suppression device, comprising: a frequency calculation module configured to calculate an actual rotor frequency of a gas-suspended high-speed motor; a control point determination module configured to determine a plurality of control points based on a current carrier cycle of the gas-suspended high-speed motor, comprising: dividing the current carrier cycle into eight time periods, wherein the starting time of the first time period and the ending time of the fifth time period are taken as a first control point, the starting time of the second time period and the ending time of the sixth time period are taken as a second control point, the starting time of the third time period and the ending time of the seventh time period are taken as a third control point, and the starting time of the fourth time period and the ending time of the eighth time period are taken as a fourth control point; a calibration module configured to jointly calculate at the plurality of control points according to the actual rotor frequency to calibrate a rotor position angle, comprising: calculating a rotor frequency fluctuation value of the gas-suspended high-speed motor at the first control point, calculating a motor load parameter at the second control point if the rotor frequency fluctuation value is greater than a frequency threshold, correcting the rotor position angle at the third control point if the motor load parameter is greater than a load threshold, and observing the rotor position angle of the gas-suspended high-speed motor at the fourth control point to determine whether the rotor position angle is corrected; and a control module configured to output a control signal to an inverter connected to the gas-suspended high-speed motor according to the calibrated rotor position angle to control the inverter to output a current signal to the gas-suspended high-speed motor.

9. The gas-suspended high-speed motor electromagnetic noise suppression device of claim 8, wherein the calibration module is configured to control operation of the gas-suspended high-speed motor according to a preset trajectory containing a plurality of acceleration segments, constant speed segments and deceleration segments, and obtain the motor load parameter according to current of the gas-suspended high-speed motor within a sampling period.

10. The gas-suspended high-speed motor electromagnetic noise suppression device of claim 9, wherein The calibration module is configured to control the gas-suspended high-speed motor to run at a first acceleration for a first time, at a constant speed for a second time, at a second acceleration for a third time, at a constant speed for a fourth time, at a first deceleration for a fifth time, at a constant speed for a sixth time, at a second deceleration for a seventh time, and at a constant speed for an eighth time, respectively, starting from zero speed, wherein the first acceleration and the first deceleration have equal magnitude and opposite direction, the second acceleration and the second deceleration have equal magnitude and opposite direction, and the first time, the third time, the fifth time, and the seventh time are equal.

11. The electromagnetic noise suppression device for the gas-suspended high-speed motor according to claim 8, wherein The calibration module is configured to determine the rotor frequency fluctuation value according to a difference between the actual rotor frequency and a target rotor frequency.

12. The electromagnetic noise suppression device for the gas-suspended high-speed motor according to claim 8, wherein The calibration module is configured to estimate the rotor frequency using a full-order sliding mode position observer, obtain a rotor frequency error according to a difference between the actual rotor frequency and the estimated rotor frequency, obtain a rotor position angle deviation based on the rotor frequency error, and correct the rotor position angle according to the rotor position angle deviation.

13. The electromagnetic noise suppression device for the gas-suspended high-speed motor according to claim 8, wherein The calibration module is configured to determine whether the rotor position angle of the gas-suspended high-speed motor is corrected according to a sliding mode surface constituted by the stator current error.

14. The electromagnetic noise suppression device for the gas-suspended high-speed motor according to any one of claims 8 to 13, wherein The actual rotor frequency is determined according to current information on a line between the gas-suspended high-speed motor and an inverter.

15. An electromagnetic noise suppression device for a gas-suspended high-speed motor, comprising: a memory; and a processor coupled to the memory, the processor being configured to execute the electromagnetic noise suppression method for the gas-suspended high-speed motor according to any one of claims 1 to 7 based on instructions stored in the memory.

16. An electromagnetic noise suppression system for a gas-suspended high-speed motor, comprising: the electromagnetic noise suppression device for the gas-suspended high-speed motor according to any one of claims 8 to 15; an inverter configured to output alternating current to the gas-suspended high-speed motor according to a control signal output by the electromagnetic noise suppression device for the gas-suspended high-speed motor; and a sampling and calculation circuit configured to sample current information of the gas-suspended high-speed motor and determine a rotor frequency of the gas-suspended high-speed motor according to the current information.

17. A non-transitory computer-readable storage medium having computer program instructions stored thereon, the instructions being executed by a processor to implement the electromagnetic noise suppression method for the gas-suspended high-speed motor according to any one of claims 1 to 8. ​

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