Permanent magnet synchronous motor control system and current detection system

Abstract

The invention discloses a permanent magnet synchronous motor control system and a current detection system, and relates to the technical field of motor control, the system comprises a sensor module provided with a modulator unit and a control module provided with a signal processing unit; the sensor module is connected with the signal processing unit in the control module through the modulator unit, and the sensor module and the control module are respectively connected with the motor; the sensor module is used for acquiring a phase current signal of the motor, and performing oversampling and noise shaping on the phase current signal by using the modulator unit to obtain a current signal; the control module is used for separating and extracting the current signal through the signal processing unit to obtain a low-frequency fundamental wave current signal and a high-frequency salient polarity current signal, and determining the rotor position and the rotating speed of the motor according to the low-frequency fundamental wave current signal and the high-frequency salient polarity current signal; and the control module is also used for outputting corresponding motor control signals to the motor according to the rotor position and the rotating speed of the motor to control the motor to operate.

Description

Technical Field

[0001] The present application relates to the field of motor control technology, and in particular to a permanent magnet synchronous motor control system and a current detection system. Background Art

[0002] Acquiring rotor position signals for traditional PMSMs (Permanent Magnet Synchronous Motors) typically requires high-precision position sensors. However, installing these sensors reduces mechanical system stability, increases system complexity, and increases application cost. Sensorless PMSMs can use an observer to estimate back-EMF in the medium- and high-speed ranges to determine rotor position. However, in the zero- and low-speed ranges, where the motor generates relatively little back-EMF, the rotor's saliency effect—the difference in magnetic reluctance at different rotor positions caused by the rotor's asymmetric geometry—is exploited. By injecting a high-frequency square wave into the control signal and monitoring the motor's salient current response, rotor position information can be acquired, enabling sensorless control of the PMSM.

[0003] To control the motor and obtain rotor position information, a current sensor chip is typically required to detect the motor phase current. In traditional high-frequency injection response current detection schemes, the current sensor output voltage signal is sampled by a successive approximation register analog-to-digital converter (SAR ADC) on the microcontroller (MCU) at a rate twice the period of the high-frequency injection signal. Signal processing is then used to separate the fundamental current from the high-frequency salient current. However, this sampling operation causes noise aliasing, and the SAR ADC's Nyquist sampling determines its high low-frequency quantization noise spectral density. This limits the signal-to-noise ratio (SNR) after separating the fundamental and high-frequency salient currents, reducing the current signal detection accuracy. However, the salient current response amplitude generated by the motor is typically small. This loss in current detection accuracy requires the use of a higher-precision current sensor, increasing system cost and significantly impacting rotor position estimation errors. Summary of the Invention

[0004] The main purpose of this application is to provide a permanent magnet synchronous motor control system and a current detection system, aiming to solve the technical problem of limited current detection accuracy caused by the high-frequency injection method in the traditional PMSM phase current detection scheme.

[0005] To achieve the above objectives, the present application proposes a permanent magnet synchronous motor control system and a current detection system, wherein the permanent magnet synchronous motor control system includes: a sensor module provided with a modulator unit and a control module provided with a signal processing unit; The sensor module is connected to the signal processing unit in the control module through the modulator unit, and the sensor module and the control module are respectively connected to the motor; The sensor module is used to obtain the phase current signal of the motor, and use the modulator unit to oversample and noise-shape the phase current signal to obtain a current signal; The control module is configured to separate and extract the current signal through the signal processing unit to obtain a low-frequency fundamental current signal and a high-frequency salient polarity current signal, and determine the rotor position and speed of the motor according to the low-frequency fundamental current signal and the high-frequency salient polarity current signal; The control module is further configured to output a corresponding motor control signal to the motor according to the rotor position and rotational speed of the motor, thereby controlling the operation of the motor.

[0006] Optionally, the sensor module includes: a current sensor unit; The current sensor unit is connected to the modulator unit and the motor respectively; The current sensor unit is used to obtain the phase current signal of the motor and send it to the modulator unit.

[0007] Optionally, the current sensor unit includes: a Hall sensor and a low noise amplifier; The Hall sensor is connected to the motor and the low noise amplifier respectively; The Hall sensor is used to obtain a Hall voltage signal proportional to the motor phase current and send the signal to the low noise amplifier; The low noise amplifier is used to amplify the Hall voltage signal to obtain a phase current signal and send the phase current signal to the modulator unit.

[0008] Optionally, the modulator unit includes: a first integrator, a second integrator and a quantizer; The first integrator is connected to the current sensor unit and the second integrator respectively, and the quantizer is connected to the second integrator and the signal processing unit respectively.

[0009] Optionally, the signal processing unit includes: a decimation filter unit, a high-frequency signal extraction unit, and a low-frequency signal extraction unit; The extraction filter unit is connected to the sensor module, the high-frequency signal extraction unit and the low-frequency signal extraction unit respectively; The decimation filter unit is used to perform anti-aliasing and downsampling processing on the current signal to obtain a high signal-to-noise ratio current signal and send it to the high-frequency signal extraction unit and the low-frequency signal extraction unit respectively; The high-frequency signal extraction unit is used to extract a high-frequency salient polarity current signal from the high signal-to-noise ratio current signal and send it to the control module; The low-frequency signal extraction unit is used to extract the low-frequency fundamental current signal from the high signal-to-noise ratio current signal and send it to the control module.

[0010] Optionally, the decimation filter unit comprises: a first cascaded integrator, a first downsampling subunit and a cascaded comb filter; The first cascade integrator is connected to the sensor module and the first down-sampling subunit respectively, and the cascade comb filter is connected to the first down-sampling subunit, the high-frequency signal extraction unit and the low-frequency signal extraction unit respectively.

[0011] Optionally, the signal processing unit further includes: a second cascade integrator; The second cascade integrator is connected to the sensor module, the high-frequency signal extraction unit and the low-frequency signal extraction unit respectively; The second cascade integrator is used to perform anti-aliasing and downsampling processing on the current signal when the modulator unit in the sensor module is an incremental modulator, to obtain a high signal-to-noise ratio current signal and send it to the high-frequency signal extraction unit and the low-frequency signal extraction unit respectively.

[0012] Optionally, the high-frequency signal extraction unit includes: a first delay subunit, a first operator, and a second downsampling subunit; The decimation filter unit is connected to the first delay subunit and the first operator respectively. The first operator is connected to the first delay subunit and the second downsampling subunit respectively. The second downsampling subunit is connected to the control module.

[0013] Optionally, the low-frequency signal extraction unit includes: a second delay subunit, a second operator and a third downsampling subunit; The decimation filter unit is connected to the second delay subunit and the second operator respectively. The second operator is connected to the second delay subunit and the third downsampling subunit respectively. The third downsampling subunit is connected to the control module.

[0014] In addition, to achieve the above-mentioned purpose, the present application also proposes a current detection system, which includes the permanent magnet synchronous motor control system as described above.

[0015] One or more technical solutions proposed in this application have at least the following effects: The present application discloses a permanent magnet synchronous motor control system and a current detection system, wherein the permanent magnet synchronous motor control system includes: a sensor module provided with a modulator unit and a control module provided with a signal processing unit; the sensor module is connected to the signal processing unit in the control module through the modulator unit, and the sensor module and the control module are respectively connected to the motor; the sensor module is used to obtain the phase current signal of the motor, and use the modulator unit to oversample and noise-shape the phase current signal to obtain a current signal; the control module is used to separate and extract the current signal through the signal processing unit to obtain a low-frequency fundamental current signal and a high-frequency salient polarity current signal, and determine the rotor position and speed of the motor based on the low-frequency fundamental current signal and the high-frequency salient polarity current signal; the control module is also used to output a corresponding motor control signal to the motor based on the rotor position and speed of the motor to control the operation of the motor. This application uses the sensor module's modulator unit to oversample and noise-shape the motor phase current signal. The control module's signal processing unit then separates and extracts the low-frequency fundamental and high-frequency salient polarity current signals, thereby accurately determining the motor rotor position and speed and outputting control signals. This achieves high-precision current detection and reliable position and speed estimation. Oversampling and noise shaping also reduce the performance requirements for the current sensor, simplifying hardware design, reducing system costs, and enhancing the system's anti-interference capabilities, improving the overall performance and stability of the permanent magnet synchronous motor control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0017] Figure 1 This is a schematic structural diagram of the first embodiment of the permanent magnet synchronous motor control system proposed in the embodiments of the present application; Figure 2 This is a first structural diagram of the second embodiment of the permanent magnet synchronous motor control system proposed in the embodiments of the present application; Figure 3 This is a second structural diagram of the second embodiment of the permanent magnet synchronous motor control system proposed in the embodiments of the present application; Figure 4 This is a third structural diagram of the second embodiment of the permanent magnet synchronous motor control system proposed in the embodiments of the present application; Figure 5This is a fourth structural diagram of the second embodiment of the permanent magnet synchronous motor control system proposed in the embodiments of the present application; Figure 6 This is a fifth structural diagram of the second embodiment of the permanent magnet synchronous motor control system proposed in the embodiments of the present application; Figure 7 This is a structural diagram of the third embodiment of the permanent magnet synchronous motor control system proposed in the embodiments of the present application.

[0018] Description of Figure Numbers:

[0019] The purpose, features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0020] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application and are not intended to limit the present application.

[0021] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0022] It should be noted that all directional indications in the embodiments of the present application (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0023] In addition, the descriptions of "first", "second", etc. in this application are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0024] The main solution of this embodiment is that the DSM (Delta-Sigma Modulator) integrated in sensor module 1 achieves oversampling, enabling digital processing to eliminate out-of-band quantization noise. Furthermore, the DSM's noise shaping function reduces the system's in-band quantization noise, further improving current signal detection accuracy. The signal processing unit 21 implemented on the MCU (control module 2) performs anti-aliasing filtering and downsampling on the DSM's output bit stream, avoiding the current detection accuracy loss caused by noise aliasing in traditional solutions and reducing the system's requirements for current sensor performance.

[0025] It should be noted that the signal processing unit 21 may be a digital signal processing (DSP).

[0026] It should also be noted that implementing the DSM and DSP on the current sensor chip (sensor module 1) and the MCU chip (control module 2), respectively, allows the current sensor chip to be produced at a higher process node for lower cost, while the DSP module is integrated into the MCU at a lower process node to reduce chip area and increase signal processing speed. However, the DSP can still be implemented on the current sensor chip.

[0027] The present application provides a solution, and the present application discloses a permanent magnet synchronous motor control system and a current detection system, wherein the permanent magnet synchronous motor control system includes: a sensor module 1 provided with a modulator unit 12 and a control module 2 provided with a signal processing unit 21; the sensor module 1 is connected to the signal processing unit 21 in the control module 2 through the modulator unit 12, and the sensor module 1 and the control module 2 are respectively connected to the motor; the sensor module 1 is used to obtain the phase current signal of the motor, and use the modulator unit 12 to oversample and noise-shape the phase current signal to obtain a current signal; the control module 2 is used to separate and extract the current signal through the signal processing unit 21 to obtain a low-frequency fundamental current signal and a high-frequency salient polarity current signal, and determine the rotor position and speed of the motor based on the low-frequency fundamental current signal and the high-frequency salient polarity current signal; the control module 2 is also used to output a corresponding motor control signal to the motor based on the rotor position and speed of the motor to control the operation of the motor. This application uses the modulator unit 12 of the sensor module 1 to oversample and noise-shape the motor phase current signal. The signal processing unit 21 of the control module 2 then separates and extracts the low-frequency fundamental and high-frequency salient polarity current signals, thereby accurately determining the motor rotor position and speed and outputting a control signal. This achieves high-precision current detection and reliable position and speed estimation. At the same time, oversampling and noise shaping reduce the performance requirements of the current sensor, simplify hardware design, reduce system costs, enhance the system's anti-interference capabilities, and improve the overall performance and stability of the permanent magnet synchronous motor control system.

[0028] Based on this, an embodiment of the present application provides a permanent magnet synchronous motor control system.

[0029] refer to Figure 1 , Figure 1 This is a structural diagram of the first embodiment of the permanent magnet synchronous motor control system proposed in the embodiments of the present application.

[0030] Considering the technical problem of limited current detection accuracy caused by the high-frequency injection method in the traditional PMSM phase current detection scheme. Figure 1 As shown, the permanent magnet synchronous motor control system of this embodiment includes: a sensor module 1 provided with a modulator unit 12 and a control module 2 provided with a signal processing unit 21; The sensor module 1 is connected to the signal processing unit 21 in the control module 2 via the modulator unit 12, and the sensor module 1 and the control module 2 are respectively connected to the motor; The sensor module 1 is used to obtain the phase current signal of the motor, and use the modulator unit 12 to oversample and noise-shape the phase current signal to obtain a current signal; The control module 2 is configured to separate and extract the current signal through the signal processing unit 21 to obtain a low-frequency fundamental current signal and a high-frequency salient polarity current signal, and determine the rotor position and speed of the motor according to the low-frequency fundamental current signal and the high-frequency salient polarity current signal; The control module 2 is further configured to output a corresponding motor control signal to the motor according to the rotor position and speed of the motor, thereby controlling the operation of the motor.

[0031] It should be noted that the permanent magnet synchronous motor control system in this embodiment is based on the high-frequency injection method. The steps of extracting the salient polarity current signal by the high-frequency injection method are as follows: Step 1, injecting a high-frequency voltage signal into the d-axis of the rotating coordinate system estimated by the motor control system. Step 2, using a current sensor chip to measure the current effect of the three-phase stator winding of the motor, wherein the measured current includes a fundamental current component and a high-frequency salient polarity current component. Step 3, the current signal sampled by the current sensor is sampled by the host computer MCU, and the fundamental current and the high-frequency salient polarity current are separated, so that the control system can complete the estimation of the rotor position and speed.

[0032] It can be understood that the control module 2 is an MCU (Micro Control Unit), the sensor module 1 is a current sensor chip, the signal processing unit 21 is a DSP (Digital signal processing), and the modulator unit 12 is a DSM (Delta-Sigma Modulator). They can also be set according to actual conditions, and this embodiment does not limit them.

[0033] It should be noted that the sensor module 1 and the control module 2 communicate via the I2C protocol, but any communication protocol such as SPI can also be used for data transmission.

[0034] In a specific implementation, the sensor module 1 primarily comprises a current sensor unit 11 and a modulator unit 12. The current sensor unit 11 detects the external input phase current signal using sensing elements such as shunt resistors or Hall effect discs and performs low-noise amplification or filtering on the current signal. The phase current signal is oversampled and noise-shaped by the modulator unit 12, generating a 1-bit digital bitstream output signal. Therefore, the MCU (control module 2) can reliably receive the current signal from the sensor module 1 via a digital communication protocol for digital signal processing within the DSP (signal processing unit 21). Within the DSP, the current signal undergoes anti-aliasing and downsampling processing through a decimation filter. The high-frequency signal extraction unit 212 and the low-frequency signal extraction unit 213 separate and extract the high-frequency salient current signal and the low-frequency fundamental current signal. These high-frequency salient current signal and the low-frequency fundamental current signal are then fed into the motor control system for rotor position and speed estimation, which then outputs the motor control signal. In particular, sensor module 1 can easily output analog voltages for current sensing signals, enabling the system to meet the requirements of low-precision current signal processing solutions sampled using a successive approximation register analog-to-digital converter (SAR ADC). Thanks to DSM's oversampling and noise shaping, the current signal after DSP processing achieves very low noise, and noise aliasing in circuit signals is also suppressed. This significantly improves the detection accuracy of salient current under high-frequency injection, reduces the requirements for current sensors, and saves costs in PMSM motor control systems.

[0035] Based on the first embodiment of the present application, in the second embodiment of the present application, the same or similar contents as those in the first embodiment can be referred to the above introduction and will not be described in detail later. Figures 2 to 6 As shown, Figure 2 This is a structural diagram of the second embodiment of the permanent magnet synchronous motor control system proposed in the embodiment of this application. Figure 3 This is a second structural diagram of the second embodiment of the permanent magnet synchronous motor control system proposed in the embodiment of the present application. Figure 4 This is a third structural diagram of the second embodiment of the permanent magnet synchronous motor control system proposed in the embodiment of the present application. Figure 5 This is a fourth structural diagram of the second embodiment of the permanent magnet synchronous motor control system proposed in the embodiment of the present application. Figure 6 This is a fifth structural diagram of the second embodiment of the permanent magnet synchronous motor control system proposed in an embodiment of the present application.

[0036] Considering that the anti-aliasing and down-sampling processing of the current signal is completed by the extraction filter unit 211, and the high-frequency signal extraction unit 212 and the low-frequency signal extraction unit 213 are used to separate and extract the high-frequency salient polarity current signal and the low-frequency fundamental current signal. Figure 2 As shown, the signal processing unit 21 of this embodiment includes: a decimation filter unit 211, a high-frequency signal extraction unit 212 and a low-frequency signal extraction unit 213; The decimation filter unit 211 is connected to the sensor module 1, the high-frequency signal extraction unit 212, and the low-frequency signal extraction unit 213 respectively; The decimation filter unit 211 is used to perform anti-aliasing and downsampling processing on the current signal to obtain a high signal-to-noise ratio current signal and send it to the high-frequency signal extraction unit 212 and the low-frequency signal extraction unit 213 respectively; The high-frequency signal extraction unit 212 is used to extract the high-frequency salient polarity current signal from the high signal-to-noise ratio current signal and send it to the control module 2; The low-frequency signal extraction unit 213 is configured to extract a low-frequency fundamental current signal from the high signal-to-noise ratio current signal and send the signal to the control module 2 .

[0037] It should be noted that the decimation filter unit 211 may be a CIC (Cascaded Integrator-Comb) filter, or may be configured according to actual conditions, which is not limited in this embodiment.

[0038] In a specific implementation, the system in this embodiment performs anti-aliasing and downsampling processing on the current signal through the extraction filter unit 211, which effectively improves the signal-to-noise ratio of the current signal and provides a purer and higher-quality signal basis for subsequent signal extraction. On this basis, the high-frequency signal extraction unit 212 can more accurately extract the high-frequency salient polarity current signal, while the low-frequency signal extraction unit 213 can more accurately extract the low-frequency fundamental current signal. This method of extracting high and low frequency signals separately not only improves the accuracy of the extraction, but also avoids the problem of reduced current detection accuracy due to noise aliasing in traditional solutions. The entire system design achieves accurate generation of motor control signals by optimizing the signal processing process, thereby improving the stability and efficiency of motor operation.

[0039] Furthermore, if Figure 4 As shown, the decimation filter unit 211 includes: a first cascaded integrator 2111, a first downsampling subunit 2112 and a cascaded comb filter 2113; The first cascade integrator 2111 is connected to the sensor module 1 and the first downsampling subunit 2112 respectively, and the cascade comb filter 2113 is connected to the first downsampling subunit 2112, the high-frequency signal extraction unit 212 and the low-frequency signal extraction unit 213 respectively.

[0040] It should be noted that the cascaded comb filter 2113 is a three-stage cascaded comb filter 2113 , and the cascaded comb filter 2113 does not need to use a multiplier and thus achieves extremely low hardware complexity.

[0041] In a specific implementation, the decimation filter unit 211 is used to implement signal downsampling and anti-aliasing filtering, which converts a 1-bit digital code stream into a high-resolution digital signal while suppressing high-frequency aliasing of noise.

[0042] Furthermore, if Figure 5 As shown, the high-frequency signal extraction unit 212 includes: a first delay subunit, a first operator and a second downsampling subunit; The decimation filter unit 211 is connected to the first delay subunit and the first operator respectively. The first operator is connected to the first delay subunit and the second downsampling subunit respectively. The second downsampling subunit is connected to the control module 2 .

[0043] Furthermore, if Figure 6 As shown, the low-frequency signal extraction unit 213 includes: a second delay subunit, a second operator and a third downsampling subunit; The decimation filter unit 211 is connected to the second delay subunit and the second operator respectively. The second operator is connected to the second delay subunit and the third downsampling subunit respectively. The third downsampling subunit is connected to the control module 2 .

[0044] In a specific implementation, the current signal, after downsampling and filtering by the decimation filter unit 211, has a high SNR (signal-to-noise ratio). This current signal then undergoes time-shifted phase subtraction and two-fold downsampling by the high-frequency signal extraction unit 212, filtering out the low-frequency fundamental current signal and generating a high-frequency salient current signal. Furthermore, the low-frequency fundamental current signal undergoes time-shifted addition and two-fold downsampling by the low-frequency signal extraction unit 213, filtering out the high-frequency salient current and generating a low-frequency fundamental current signal. This signal processing method avoids noise aliasing during high-frequency salient current extraction and eliminates the need for additional hardware bandpass filters, improving control system accuracy and reducing hardware costs.

[0045] Furthermore, the sensor module 1 includes: a current sensor unit 11; The current sensor unit 11 is connected to the modulator unit 12 and the motor respectively; The current sensor unit 11 is used to obtain the phase current signal of the motor and send it to the modulator unit 12 .

[0046] Furthermore, if Figure 2 As shown, the current sensor unit 11 includes: a Hall sensor 111 and a low noise amplifier 112; The Hall sensor 111 is connected to the motor and the low noise amplifier 112 respectively; The Hall sensor 111 is used to obtain a Hall voltage signal proportional to the motor phase current and send it to the low noise amplifier 112; The low noise amplifier 112 is used to amplify the Hall voltage signal to obtain a phase current signal and send the phase current signal to the modulator unit 12 .

[0047] In a specific implementation, the Hall sensor 111 characterizes the current magnitude by detecting the magnetic field strength generated when the current passes through the conductor. The Hall sensor 111 generates a weak output voltage proportional to the current magnitude, which will be low-noise amplified by the low-noise amplifier 112 so that it can be recognized and processed by the modulator unit 12.

[0048] Furthermore, if Figure 3 As shown, the modulator unit 12 includes: a first integrator 121, a second integrator 122 and a quantizer 123; The first integrator 121 is connected to the current sensor unit 11 and the second integrator 122 respectively, and the quantizer 123 is connected to the second integrator 122 and the signal processing unit 21 respectively.

[0049] In a specific implementation, the modulator unit 12 in this embodiment is implemented using a second-order CIFB structure. The second-order CIFB structure introduces a quantizer 123 in the loop to suppress in-band quantization noise and improves stability through local feedback. The modulator unit 12 can also be implemented using any other form of structure, which is not limited in this embodiment.

[0050] Based on the second embodiment of the present application, in the third embodiment of the present application, the same or similar contents as those in the second embodiment can be referred to the above introduction and will not be described in detail later. Figure 7 , Figure 7 This is a structural diagram of the third embodiment of the permanent magnet synchronous motor control system proposed in the embodiments of the present application.

[0051] Considering that the modulator unit 12 in the sensor module 1 adopts the IDSM structure (Incremental Delta-Sigma Modulator, incremental Delta-Sigma modulator). Figure 5 As shown, the signal processing unit 21 of this embodiment further includes: a second cascade integrator 214; The second cascade integrator 214 is connected to the sensor module 1, the high-frequency signal extraction unit 212 and the low-frequency signal extraction unit 213 respectively; The second cascade integrator 214 is used to perform anti-aliasing and downsampling processing on the current signal when the modulator unit 12 in the sensor module 1 is an incremental modulator, to obtain a high signal-to-noise ratio current signal and send it to the high-frequency signal extraction unit 212 and the low-frequency signal extraction unit 213 respectively.

[0052] In a specific implementation, the modulator unit 12 in this embodiment adopts an IDSM structure. Unlike the continuous operation mode of the traditional DSM (modulator unit 12), its periodic reset operation allows for multi-channel multiplexing, thereby enabling multi-channel current measurement and reducing system design costs. On the other hand, the IDSM design eliminates the need to implement a CIC decimation filter (decimation filter unit 211) in the DSP (signal processing unit 21). The downsampling filtering operation can be completed using only the second cascade integrator 214. Figure 7 As shown, the second cascaded integrator 214 includes a reset switch. In this embodiment, the IDSM and second cascaded integrator 214 perform a periodic reset operation at a frequency twice that of the high-frequency injection signal. Compared to the CIC decimation filter (decimation filter unit 211) design in the second embodiment, this embodiment achieves the same signal processing without the need for an additional cascaded comb filter 2113, thereby effectively reducing the complexity of the digital circuit.

[0053] In addition, to achieve the above-mentioned purpose, the present application also proposes a current detection system, which includes the permanent magnet synchronous motor control system as described above.

[0054] The above are only preferred embodiments of the present application and do not limit the scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the scope of protection of the present application.

Claims

1. A permanent magnet synchronous motor control system, characterized in that: The permanent magnet synchronous motor control system includes: a sensor module provided with a modulator unit and a control module provided with a signal processing unit; The sensor module is connected to the signal processing unit in the control module through the modulator unit, and the sensor module and the control module are respectively connected to the motor; The sensor module is used to obtain the phase current signal of the motor, and use the modulator unit to oversample and noise-shape the phase current signal to obtain a current signal; The control module is configured to separate and extract the current signal through the signal processing unit to obtain a low-frequency fundamental current signal and a high-frequency salient polarity current signal, and determine the rotor position and speed of the motor according to the low-frequency fundamental current signal and the high-frequency salient polarity current signal; The control module is further configured to output a corresponding motor control signal to the motor according to the rotor position and rotational speed of the motor, thereby controlling the operation of the motor.

2. The permanent magnet synchronous motor control system according to claim 1, characterized in that: The sensor module includes: a current sensor unit; The current sensor unit is connected to the modulator unit and the motor respectively; The current sensor unit is used to obtain the phase current signal of the motor and send it to the modulator unit.

3. The permanent magnet synchronous motor control system according to claim 2, characterized in that: The current sensor unit includes: a Hall sensor and a low noise amplifier; The Hall sensor is connected to the motor and the low noise amplifier respectively; The Hall sensor is used to obtain a Hall voltage signal proportional to the motor phase current and send the signal to the low noise amplifier; The low noise amplifier is used to amplify the Hall voltage signal to obtain a phase current signal and send the phase current signal to the modulator unit.

4. The permanent magnet synchronous motor control system according to claim 2, characterized in that: The modulator unit includes: a first integrator, a second integrator and a quantizer; The first integrator is connected to the current sensor unit and the second integrator respectively, and the quantizer is connected to the second integrator and the signal processing unit respectively.

5. The permanent magnet synchronous motor control system according to claim 1, characterized in that: The signal processing unit includes: a decimation filter unit, a high-frequency signal extraction unit and a low-frequency signal extraction unit; The extraction filter unit is connected to the sensor module, the high-frequency signal extraction unit and the low-frequency signal extraction unit respectively; The decimation filter unit is used to perform anti-aliasing and downsampling processing on the current signal to obtain a high signal-to-noise ratio current signal and send it to the high-frequency signal extraction unit and the low-frequency signal extraction unit respectively; The high-frequency signal extraction unit is used to extract a high-frequency salient polarity current signal from the high signal-to-noise ratio current signal and send it to the control module; The low-frequency signal extraction unit is used to extract the low-frequency fundamental current signal from the high signal-to-noise ratio current signal and send it to the control module.

6. The permanent magnet synchronous motor control system according to claim 5, characterized in that: The decimation filter unit comprises: a first cascaded integrator, a first downsampling subunit and a cascaded comb filter; The first cascade integrator is connected to the sensor module and the first down-sampling subunit respectively, and the cascade comb filter is connected to the first down-sampling subunit, the high-frequency signal extraction unit and the low-frequency signal extraction unit respectively.

7. The permanent magnet synchronous motor control system according to claim 5, characterized in that: The signal processing unit further includes: a second cascade integrator; The second cascade integrator is connected to the sensor module, the high-frequency signal extraction unit and the low-frequency signal extraction unit respectively; The second cascade integrator is used to perform anti-aliasing and downsampling processing on the current signal when the modulator unit in the sensor module is an incremental modulator, to obtain a high signal-to-noise ratio current signal and send it to the high-frequency signal extraction unit and the low-frequency signal extraction unit respectively.

8. The permanent magnet synchronous motor control system according to claim 5, characterized in that: The high-frequency signal extraction unit includes: a first delay subunit, a first operator and a second downsampling subunit; The decimation filter unit is connected to the first delay subunit and the first operator respectively. The first operator is connected to the first delay subunit and the second downsampling subunit respectively. The second downsampling subunit is connected to the control module.

9. The permanent magnet synchronous motor control system according to claim 5, characterized in that: The low-frequency signal extraction unit includes: a second delay subunit, a second operator and a third downsampling subunit; The decimation filter unit is connected to the second delay subunit and the second operator respectively. The second operator is connected to the second delay subunit and the third downsampling subunit respectively. The third downsampling subunit is connected to the control module.

10. A current detection system, characterized in that: The current detection system includes the permanent magnet synchronous motor control system according to any one of claims 1 to 9.

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