Permanent magnet synchronous motor control system and current detection system

Abstract

The application 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 to the signal processing unit in the control module through the modulator unit, and the sensor module and the control module are connected to a motor respectively. The sensor module is used for acquiring phase current signals of the motor, and the modulator unit is used for oversampling and noise shaping of the phase current signals to obtain current signals. The control module is used for separating and extracting the current signals through the signal processing unit to obtain low-frequency fundamental current signals and high-frequency salient-pole current signals, and is used for determining the rotor position and the rotating speed of the motor according to the low-frequency fundamental current signals and the high-frequency salient-pole current signals. 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, and is used for controlling the motor to operate.

Description

TECHNICAL FIELD

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

[0002] The acquisition of traditional PMSM (Permanent Magnet Synchronous Motor) rotor position signals usually needs to use high-precision position sensors, but the installation of sensors reduces the stability of the mechanical system, improves the complexity of the system, and increases the application cost. The PMSM without position sensors can construct an observer in the medium-high speed area to estimate the back electromotive force and obtain the rotor position. In the low speed area, due to the small back electromotive force generated by the motor, the salient pole effect of the rotor is used, that is, the difference in magnetic resistance of the rotor at different positions caused by the asymmetry of the rotor geometry is used, the rotor position information is obtained by injecting a high-frequency square wave into the control signal and monitoring the salient pole current response generated by the motor, so as to realize the sensorless control of the PMSM.

[0003] In order to realize the control of the motor and the acquisition of the rotor position information, a current sensor chip is usually used to detect the motor phase current. In the traditional high-frequency injection response current detection scheme, the current sensor output voltage signal is sampled at a rate of 2 times the high-frequency injection signal period by the SAR ADC (Successive Approximation Register Analog to Digital Converter) carried on the MCU (Micro Control Unit), and the fundamental current and the high-frequency salient pole current are separated through signal processing. However, the sampling operation will cause noise aliasing, and the Nyquist sampling of the SAR ADC determines its high low-frequency quantization noise spectral density, so it will limit the SNR (Signal to Noise Ratio) of the separated fundamental current and high-frequency salient pole current, and reduce the detection accuracy of the current signal. However, the salient pole current response amplitude generated by the motor is usually small, and the loss of current detection accuracy requires the system to use a higher precision current sensor, which increases the system cost, otherwise it will seriously affect the rotor position estimation error. SUMMARY

[0004] The main purpose of the present application is to provide a permanent magnet synchronous motor control system and a current detection system, which aims 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] In order to achieve the above object, the application provides a permanent magnet synchronous motor control system and a current detection system, the permanent magnet synchronous motor control system comprises a sensor module provided with a modulator unit and a control module provided with a signal processing unit;

[0006] 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 connected with a motor respectively;

[0007] The sensor module is used for acquiring phase current signals of the motor and obtaining current signals by oversampling and noise shaping of the phase current signals through the modulator unit.

[0008] The control module is used for separating and extracting the current signals to obtain low-frequency fundamental current signals and high-frequency saliency current signals through the signal processing unit, and determining rotor position and speed of the motor according to the low-frequency fundamental current signals and the high-frequency saliency current signals.

[0009] The control module is further used for outputting corresponding motor control signals to the motor according to the rotor position and the speed of the motor, and controlling the motor to operate.

[0010] Optionally, the sensor module comprises a current sensor unit.

[0011] The current sensor unit is connected with the modulator unit and the motor respectively.

[0012] The current sensor unit is used for acquiring phase current signals of the motor and sending the phase current signals to the modulator unit.

[0013] Optionally, the current sensor unit comprises a Hall sensor and a low-noise amplifier.

[0014] The Hall sensor is connected with the motor and the low-noise amplifier respectively.

[0015] The Hall sensor is used for acquiring Hall voltage signals proportional to phase currents of the motor and sending the Hall voltage signals to the low-noise amplifier.

[0016] The low-noise amplifier is used for amplifying the Hall voltage signals to obtain phase current signals and sending the phase current signals to the modulator unit.

[0017] Optionally, the modulator unit comprises a first integrator, a second integrator and a quantizer.

[0018] The first integrator is connected with the current sensor unit and the second integrator respectively, and the quantizer is connected with the second integrator and the signal processing unit respectively.

[0019] Optionally, the signal processing unit comprises: an extraction filter unit, a high-frequency signal extraction unit and a low-frequency signal extraction unit;

[0020] The extraction filter unit is connected with the sensor module, the high-frequency signal extraction unit and the low-frequency signal extraction unit respectively;

[0021] The extraction filter unit is configured to perform anti-aliasing and decimation processing on the current signal to obtain a high signal-to-noise ratio current signal and send the high signal-to-noise ratio current signal to the high-frequency signal extraction unit and the low-frequency signal extraction unit respectively;

[0022] The high-frequency signal extraction unit is configured to extract a high-frequency salient-pole current signal from the high signal-to-noise ratio current signal and send the high-frequency salient-pole current signal to the control module;

[0023] The low-frequency signal extraction unit is configured to extract a low-frequency fundamental current signal from the high signal-to-noise ratio current signal and send the low-frequency fundamental current signal to the control module.

[0024] Optionally, the extraction filter unit comprises: a first cascaded integrator, a first decimation subunit and a cascaded comb filter;

[0025] The first cascaded integrator is connected with the sensor module and the first decimation subunit respectively, and the cascaded comb filter is connected with the first decimation subunit, the high-frequency signal extraction unit and the low-frequency signal extraction unit respectively.

[0026] Optionally, the signal processing unit further comprises: a second cascaded integrator;

[0027] The second cascaded integrator is connected with the sensor module, the high-frequency signal extraction unit and the low-frequency signal extraction unit respectively;

[0028] The second cascaded integrator is configured to perform anti-aliasing and decimation processing on the current signal to obtain a high signal-to-noise ratio current signal and send the high signal-to-noise ratio current signal to the high-frequency signal extraction unit and the low-frequency signal extraction unit respectively when the modulator unit in the sensor module is an incremental modulator.

[0029] Optionally, the high-frequency signal extraction unit comprises: a first delay subunit, a first operator and a second decimation subunit;

[0030] The extraction filter unit is connected with the first delay subunit and the first operator respectively, the first operator is connected with the first delay subunit and the second decimation subunit respectively, and the second decimation subunit is connected with the control module.

[0031] Optionally, the low-frequency signal extraction unit comprises: a second delay subunit, a second operator and a third decimation subunit;

[0032] The extraction filter unit is connected with the second delay subunit and the second operator respectively, the second operator is connected with the second delay subunit and the third down-sampling subunit respectively, and the third down-sampling subunit is connected with the control module.

[0033] In addition, to achieve the above object, the application further provides a current detection system, which comprises the permanent magnet synchronous motor control system as described above.

[0034] The one or more technical solutions provided by the application have at least the following effects:

[0035] The application discloses a permanent magnet synchronous motor control system and a current detection system, the permanent magnet synchronous motor control system comprising: 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 connected with a motor respectively; the sensor module is used for acquiring phase current signals of the motor and obtaining current signals by oversampling and noise shaping of the phase current signals through the modulator unit; the control module is used for obtaining low-frequency fundamental current signals and high-frequency saliency current signals by separating and extracting the current signals through the signal processing unit, and determining rotor position and speed of the motor according to the low-frequency fundamental current signals and the high-frequency saliency current signals; and the control module is further used for outputting corresponding motor control signals to the motor according to the rotor position and the speed of the motor, so as to control the motor to operate. The modulator unit of the sensor module is used for oversampling and noise shaping of the motor phase current signals, and then the low-frequency fundamental current signals and the high-frequency saliency current signals are separated and extracted through the signal processing unit of the control module, so that the rotor position and the speed of the motor are accurately determined and the control signals are outputted, high-precision current detection and reliable position and speed estimation are realized. Meanwhile, the oversampling and noise shaping reduce the requirement for the performance of the current sensor, simplify the hardware design, reduce the system cost, enhance the anti-interference ability of the system, and improve the overall performance and stability of the permanent magnet synchronous motor control system. BRIEF DESCRIPTION OF DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, for those skilled in the art, other drawings can also be obtained from these drawings without any creative effort.

[0037] Figure 1 The structure schematic diagram of the first embodiment of the permanent magnet synchronous motor control system provided by the application.

[0038] Figure 2 A first structural schematic diagram of a second embodiment of the permanent magnet synchronous motor control system proposed in the embodiments of the present application is shown in FIG. 2.

[0039] Figure 3 A second structural schematic diagram of the second embodiment of the permanent magnet synchronous motor control system proposed in the embodiments of the present application is shown in FIG. 3.

[0040] Figure 4 A third structural schematic diagram of the second embodiment of the permanent magnet synchronous motor control system proposed in the embodiments of the present application is shown in FIG. 4.

[0041] Figure 5 A fourth structural schematic diagram of the second embodiment of the permanent magnet synchronous motor control system proposed in the embodiments of the present application is shown in FIG. 5.

[0042] Figure 6 A fifth structural schematic diagram of the second embodiment of the permanent magnet synchronous motor control system proposed in the embodiments of the present application is shown in FIG. 6.

[0043] Figure 7 A structural schematic diagram of a third embodiment of the permanent magnet synchronous motor control system proposed in the embodiments of the present application is shown in FIG. 7.

[0044] Explanation of reference signs:

[0045]

[0046] The object, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0047] It should be understood that the specific embodiments described herein merely set forth the preferred embodiments of the present application and do not limit the present application.

[0048] The technical solutions in the embodiments of the present application will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0049] It should be noted that all the directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative position relationship, movement condition, etc. between the components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications will also change accordingly.

[0050] In addition, the descriptions involving "first", "second" and the like in the present application are only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the technical features or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of various embodiments can be combined with each other, but it must be based on the realization of ordinary skilled in the art, when the combination of technical solutions appears contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist, nor within the protection scope required by the present application.

[0051] The main solution of the embodiment of the present application is that the DSM (Delta-Sigma Modulator) integrated on the sensor module 1 realizes oversampling, so that the digital processing method can be used to eliminate the out-of-band quantization noise. In addition, the noise shaping function of DSM can reduce the in-band quantization noise of the system, thereby further improving the detection accuracy of the current signal. The signal processing unit 21 realized by the MCU end (control module 2) performs anti-aliasing filtering and downsampling processing on the output code stream of DSM, avoiding the current detection accuracy decline caused by noise aliasing in the traditional scheme, and reducing the requirement of the system on the performance of the current sensor.

[0052] It should be noted that the above signal processing unit 21 can be a digital signal processing (Digital signal processing, DSP).

[0053] It should be noted that the DSM and DSP are realized on the current sensor chip (sensor module 1) and MCU chip (control module 2) respectively, so that the current sensing chip can be produced at a higher process node to realize low cost, while the DSP module is integrated on the MCU with lower process node to reduce chip area and improve signal processing speed. But the DSP can still be realized on the current sensor chip.

[0054] This application provides a solution, disclosing a permanent magnet synchronous motor control system and a current detection system. The permanent magnet synchronous motor control system includes: a sensor module 1 equipped with a modulator unit 12 and a control module 2 equipped 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 a motor; the sensor module 1 is used to acquire 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 a low-frequency fundamental current signal and a high-frequency salient polarity current signal from the current signal through the signal processing unit 21, 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 utilizes the modulator unit 12 of sensor module 1 to oversample and noise-shape the motor phase current signal. The low-frequency fundamental wave and high-frequency salient polarity current signal are then separated and extracted by the signal processing unit 21 of control module 2, 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. Simultaneously, oversampling and noise shaping reduce the performance requirements of the current sensor, simplify hardware design, lower system costs, enhance the system's anti-interference capability, and improve the overall performance and stability of the permanent magnet synchronous motor control system.

[0055] Based on this, the embodiments of this application provide a permanent magnet synchronous motor control system.

[0056] refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of the first embodiment of the permanent magnet synchronous motor control system proposed in this application.

[0057] Considering the technical problem of limited current detection accuracy caused by high-frequency injection methods in traditional PMSM phase current detection schemes, such as... Figure 1 As shown, the permanent magnet synchronous motor control system described in this embodiment includes: a sensor module 1 equipped with a modulator unit 12 and a control module 2 equipped with a signal processing unit 21;

[0058] 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;

[0059] The sensor module 1 is configured to acquire the phase current signal of the motor and to obtain the current signal by oversampling and noise shaping the phase current signal by using the modulator unit 12.

[0060] The control module 2 is configured to separate and extract the current signal by the signal processing unit 21 to obtain the low-frequency fundamental current signal and the high-frequency saliency current signal, and to determine the rotor position and the speed of the motor according to the low-frequency fundamental current signal and the high-frequency saliency current signal.

[0061] The control module 2 is further configured to output the corresponding motor control signal to the motor according to the rotor position and the speed of the motor, so as to control the operation of the motor.

[0062] It should be noted that the permanent magnet synchronous motor control system in the embodiment is based on the high-frequency injection method. The steps of extracting the saliency current signal by the high-frequency injection method are as follows: step one, injecting a high-frequency voltage signal to the d-axis of the rotating coordinate system estimated by the motor control system; step two, measuring the current effect of the three-phase stator winding of the motor by using the current sensor chip, wherein the measured current includes the fundamental current component and the high-frequency saliency current component; and step three, sampling the current signal of the current sensor by the upper computer MCU, and separating the fundamental current and the high-frequency saliency current, so that the control system can complete the estimation of the rotor position and the speed.

[0063] It should 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 be set according to actual conditions, and the embodiment is not limited in this regard.

[0064] It should be noted that the sensor module 1 and the control module 2 communicate by using the I2C protocol, but any communication protocol such as SPI can also be used for data transmission.

[0065] In a specific implementation, the sensor module 1 mainly includes a current sensor unit 11 and a modulator unit 12. The current sensor unit 11 detects an external input phase current signal through a sensing element such as a shunt resistor or a Hall disc, 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 to generate a signal output in the form of a 1-bit digital code stream. Therefore, the MCU (control module 2) can reliably receive the current signal from the sensor module 1 through a digital communication protocol, so as to perform digital signal processing in the DSP (signal processing unit 21). Among them, the current signal will complete the anti-aliasing and downsampling processing of the current signal through the decimation filter in the DSP, and the high-frequency salient-pole current signal and the low-frequency fundamental current signal are separated and extracted through the high-frequency signal extraction unit 212 and the low-frequency signal extraction unit 213. Subsequently, the high-frequency salient-pole current signal and the low-frequency fundamental current signal are fed to the motor control system to estimate the motor rotor position and speed and output motor control signals. In particular, the sensor module 1 can also easily realize analog voltage output of the current sensing signal, so that the system can also satisfy the low-precision current signal processing scheme through the SAR ADC (Successive Approximation Register Analog to Digital Converter, successive approximation register analog-to-digital converter) sampling. Benefiting from the oversampling and noise shaping of the DSM, the current signal processed by the DSP has very low noise, and the noise aliasing phenomenon of the circuit signal is also suppressed, thereby greatly improving the detection accuracy of the salient-pole current under high-frequency injection, reducing the requirements on the current sensor, and saving the cost of the PMSM motor control system.

[0066] Based on the first embodiment of the present application, in the second embodiment of the present application, the same or similar contents as the above-mentioned first embodiment can be referred to the above introduction, and the following will not be described in detail. On this basis, please refer to Figures 2-6 , as shown in Figure 2 , the second structure schematic diagram of the permanent magnet synchronous motor control system second embodiment proposed by the embodiment of the present application, Figure 3 , the second structure schematic diagram of the permanent magnet synchronous motor control system second embodiment proposed by the embodiment of the present application, Figure 4 , the third structure schematic diagram of the permanent magnet synchronous motor control system second embodiment proposed by the embodiment of the present application, Figure 5 , the fourth structure schematic diagram of the permanent magnet synchronous motor control system second embodiment proposed by the embodiment of the present application, Figure 6 , the fifth structure schematic diagram of the permanent magnet synchronous motor control system second embodiment proposed by the embodiment of the present application.

[0067] It is considered that the anti-aliasing and down-sampling processing of the current signal is completed by the decimation filter unit 211, and the high-frequency salient-pole current signal and the low-frequency fundamental current signal are separated by the high-frequency signal extraction unit 212 and the low-frequency signal extraction unit 213. As shown in Figure 2 The signal processing unit 21 in the embodiment includes a decimation filter unit 211, a high-frequency signal extraction unit 212, and a low-frequency signal extraction unit 213.

[0068] 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.

[0069] The decimation filter unit 211 is configured to perform anti-aliasing and down-sampling processing on the current signal to obtain a high signal-to-noise ratio current signal and send the high signal-to-noise ratio current signal to the high-frequency signal extraction unit 212 and the low-frequency signal extraction unit 213, respectively.

[0070] The high-frequency signal extraction unit 212 is configured to extract a high-frequency salient-pole current signal from the high signal-to-noise ratio current signal and send the high-frequency salient-pole current signal to the control module 2.

[0071] 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 low-frequency fundamental current signal to the control module 2.

[0072] It should be noted that the decimation filter unit 211 can be a CIC (Cascaded Integrator-Comb) filter, or can be set by itself according to actual conditions, and the embodiment does not limit it.

[0073] In a specific implementation, the system in the embodiment performs anti-aliasing and down-sampling processing on the current signal by the decimation filter unit 211, 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-pole current signal, and the low-frequency signal extraction unit 213 can more accurately extract the low-frequency fundamental current signal. This way of extracting high and low frequency signals separately not only improves the accuracy of extraction, but also avoids the problem of reduced current detection accuracy caused by noise aliasing in traditional solutions. The whole system design optimizes the signal processing process to achieve accurate generation of motor control signals, thereby improving the stability and efficiency of motor operation.

[0074] Further, as shown in Figure 4 The decimation filter unit 211 includes a first cascaded integrator 2111, a first down-sampling subunit 2112, and a cascaded comb filter 2113.

[0075] The first cascade integrator 2111 is connected with the sensor module 1 and the first down-sampling subunit 2112 respectively, and the cascade comb filter 2113 is connected with the first down-sampling subunit 2112, the high-frequency signal extraction unit 212 and the low-frequency signal extraction unit 213 respectively.

[0076] It should be noted that the cascade comb filter 2113 is a three-stage cascade comb filter 2113, which realizes extremely low hardware complexity without using a multiplier.

[0077] In a specific implementation, the decimation filter unit 211 is used to realize signal down-sampling 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.

[0078] Further, as shown in Figure 5 The high-frequency signal extraction unit 212 includes a first delay subunit, a first operator and a second down-sampling subunit.

[0079] The decimation filter unit 211 is connected with the first delay subunit and the first operator respectively, the first operator is connected with the first delay subunit and the second down-sampling subunit respectively, and the second down-sampling subunit is connected with the control module 2.

[0080] Further, as shown in Figure 6 The low-frequency signal extraction unit 213 includes a second delay subunit, a second operator and a third down-sampling subunit.

[0081] The decimation filter unit 211 is connected with the second delay subunit and the second operator respectively, the second operator is connected with the second delay subunit and the third down-sampling subunit respectively, and the third down-sampling subunit is connected with the control module 2.

[0082] In a specific implementation, the current signal filtered by the decimation filter unit 211 has a very high SNR (signal-to-noise ratio), and then the current signal is subjected to time shift subtraction and 2 times down-sampling operation by the high-frequency signal extraction unit 212, so as to realize filtering of the low-frequency fundamental current signal and obtain a high-frequency salient-pole current signal. In addition, the low-frequency fundamental current signal will be subjected to time shift addition and 2 times down-sampling operation by the low-frequency signal extraction unit 213, so as to realize filtering of the high-frequency salient-pole current and obtain a low-frequency fundamental current signal. Through the above signal processing method, noise aliasing in extraction of the high-frequency salient-pole current is avoided, and no additional hardware band-pass filter is needed, which improves the control system precision and reduces the hardware cost.

[0083] Further, the sensor module 1 comprises: a current sensor unit 11;

[0084] The current sensor unit 11 is connected with the modulator unit 12 and the motor respectively.

[0085] The current sensor unit 11 is configured to acquire the phase current signal of the motor and send it to the modulator unit 12.

[0086] Further, as shown in Figure 2 The current sensor unit 11 comprises: a Hall sensor 111 and a low noise amplifier 112.

[0087] The Hall sensor 111 is connected with the motor and the low noise amplifier 112 respectively.

[0088] The Hall sensor 111 is configured to acquire the Hall voltage signal proportional to the phase current of the motor and send it to the low noise amplifier 112.

[0089] The low noise amplifier 112 is configured to amplify the Hall voltage signal to obtain the phase current signal and send it to the modulator unit 12.

[0090] In a specific implementation, the Hall sensor 111 represents the current size by detecting the magnetic field strength generated when the current passes through the conductor, and the weak output voltage proportional to the current size generated by the Hall sensor 111 is amplified by the low noise amplifier 112, so that it can be recognized and processed by the modulator unit 12.

[0091] Further, as shown in Figure 3 The modulator unit 12 comprises: a first integrator 121, a second integrator 122 and a quantizer 123.

[0092] The first integrator 121 is connected with the current sensor unit 11 and the second integrator 122 respectively, and the quantizer 123 is connected with the second integrator 122 and the signal processing unit 21 respectively.

[0093] In a specific implementation, the modulator unit 12 in this embodiment is implemented by using a second-order CIFB structure, which introduces a quantizer 123 in the loop to realize the suppression of in-band quantization noise, and improves the stability by local feedback. The modulator unit 12 can also be implemented by using any other form of structure, and this embodiment is not limited thereto.

[0094] Based on the second embodiment of the present application, in the third embodiment of the present application, the same or similar contents as the above-mentioned second embodiment can be referred to the above introduction, and will not be described hereinafter. On this basis, please refer to Figure 7 ,Figure 7 A structure diagram of a third embodiment of a permanent magnet synchronous motor control system proposed by the embodiment of the present application.

[0095] The modulator unit 12 in the sensor module 1 is considered to adopt an IDSM structure (Incremental Delta-Sigma Modulator). As shown in the figure, the signal processing unit 21 in the embodiment also includes a second cascade integrator 214. Figure 5

[0096] The second cascade integrator 214 is connected with the sensor module 1, the high-frequency signal extraction unit 212 and the low-frequency signal extraction unit 213 respectively.

[0097] The second cascade integrator 214 is configured to, when the modulator unit 12 in the sensor module 1 is an incremental modulator, perform anti-aliasing and decimation processing on the current signal, obtain a high signal-to-noise ratio current signal and send the current signal to the high-frequency signal extraction unit 212 and the low-frequency signal extraction unit 213 respectively.

[0098] In the specific implementation, the modulator unit 12 in the embodiment adopts an IDSM structure, which is different from the continuous operation mode of the traditional DSM (modulator unit 12). The periodic reset operation allows the implementation of multi-channel multiplexing, so that multi-channel current measurement can be performed, and the system design cost is reduced. On the other hand, the design of the IDSM makes it unnecessary to implement a CIC decimation filter (decimation filter unit 211) in the DSP (signal processing unit 21), and only the second cascade integrator 214 can complete the decimation filtering operation. As shown in the figure, the second cascade integrator 214 is provided with a reset switch. In the embodiment, the IDSM and the second cascade integrator 214 are periodically reset at a frequency twice that of the high-frequency injection signal. Compared with the design of the CIC decimation filter (decimation filter unit 211) in the second embodiment, the scheme of the embodiment can complete the same signal processing without an additional cascade comb filter 2113, thereby effectively reducing the complexity of the digital circuit. Figure 7

[0099] In addition, to achieve the above object, the present application also proposes a current detection system, which comprises the permanent magnet synchronous motor control system as described above.

[0100] The above is only the preferred embodiment of the present application, and does not limit the scope of the present application. Any equivalent structure or equivalent flow transformation based on the content of the specification and drawings of the present application, or direct or indirect application in other related technical fields, is also included in the protection scope 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 equipped with a modulator unit and a control module equipped 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 acquire the phase current signal of the motor, and to use the modulator unit to oversample and noise-shape the phase current signal to obtain the 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 to 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 according to the rotor position and speed of the motor, so as to control the operation of the motor; The signal processing unit includes: a decimation filter unit, a high-frequency signal extraction unit, and a low-frequency signal extraction unit; The decimation 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, which is then sent 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.

2. The permanent magnet synchronous motor control system as described in 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 acquire the phase current signal of the motor and send it to the modulator unit.

3. The permanent magnet synchronous motor control system as described in 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 acquire a Hall voltage signal that is proportional to the motor phase current and send it to the low-noise amplifier; The low-noise amplifier is used to amplify the Hall voltage signal to obtain the phase current signal and send it to the modulator unit.

4. The permanent magnet synchronous motor control system as described in 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 as described in claim 1, characterized in that, The decimation filter unit includes: a first cascaded integrator, a first downsampling subunit, and a cascaded comb filter; The first cascaded integrator is connected to the sensor module and the first downsampling subunit, respectively, and the cascaded comb filter is connected to the first downsampling subunit, the high-frequency signal extraction unit and the low-frequency signal extraction unit, respectively.

6. The permanent magnet synchronous motor control system as described in claim 1, characterized in that, The signal processing unit further includes: a second cascaded integrator; The second cascaded integrator is connected to the sensor module, the high-frequency signal extraction unit, and the low-frequency signal extraction unit, respectively. The second cascaded 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.

7. The permanent magnet synchronous motor control system as described in claim 1, characterized in that, The high-frequency signal extraction unit includes: a first delay subunit, a first arithmetic unit, and a second downsampling subunit; The decimation filter unit is connected to the first delay subunit and the first arithmetic unit, respectively. The first arithmetic unit is connected to the first delay subunit and the second downsampling subunit, respectively. The second downsampling subunit is connected to the control module.

8. The permanent magnet synchronous motor control system as described in claim 1, characterized in that, The low-frequency signal extraction unit includes: a second delay subunit, a second arithmetic unit, and a third downsampling subunit; The decimation filter unit is connected to the second delay subunit and the second arithmetic unit, respectively. The second arithmetic unit is connected to the second delay subunit and the third downsampling subunit, respectively. The third downsampling subunit is connected to the control module.

9. 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 8.

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