Motor rotor position detection method and device, chip and motor control system

Abstract

The application provides a motor rotor position detection method and device, a chip and a motor control system. When the motor rotor position detection method detects the motor position, the chip controls the three-phase inverter output voltage signal through the injected rotating high-frequency voltage signal, and the chip receives the three-phase stator current output by the three-phase inverter to the permanent magnet synchronous motor in the current period. Secondly, the chip carries out band-pass filtering on the three-phase stator current according to the electrical angular frequency of the permanent magnet synchronous motor in the last period to obtain the corresponding high-frequency component. Then, the chip converts the high-frequency component to the high-frequency synchronous rotating coordinate system and obtains the corresponding low-frequency component after low-pass filtering. Finally, the chip determines the rotor position of the motor in the current period according to the low-frequency component and the angle error value determined according to the rotor position of the permanent magnet synchronous motor in the last period, thereby reducing the phase shift caused by filtering and further reducing the error of the rotor position information.

Description

Technical Field

[0001] This application relates to the field of motor technology, and in particular to a method and device for detecting the rotor position of a motor, a chip, and a motor control system. Background Technology

[0002] Permanent magnet synchronous motors (PMSMs) have advantages such as high power density, high efficiency, and relatively simple control, and are widely used in various fields. When controlling a PMSM, it is usually necessary to obtain the rotor position information. Currently, position sensors, such as rotary transformers and photoelectric encoders, are generally used to obtain the rotor position. However, position sensors are costly and have poor adaptability to complex environments. Using sensorless control algorithms is an effective solution. Among these methods, the rotating high-frequency injection method is one approach to achieve sensorless control of PMSMs, typically used for zero-speed start-up and low-speed operation. The rotating high-frequency injection method injects a rotating high-frequency voltage into the two-phase stationary coordinate system of the motor. Based on the motor's salient polarity, it generates a high-frequency response current containing rotor position information. By extracting this current and calculating the rotor position information within it, sensorless control of the motor can be achieved. However, the rotating high-frequency injection method requires bandpass and low-pass filtering during calculation, which causes a phase shift in the current signal, resulting in a larger error in the extracted rotor position information and thus reducing motor efficiency. Summary of the Invention

[0003] This application provides a method, device, chip, and motor control system for detecting the rotor position of a motor, which solves the problem of large errors in rotor position information when locating the motor position based on the high-frequency rotary injection method.

[0004] To achieve the above objectives, this application adopts the following technical solution:

[0005] Firstly, a method for detecting the rotor position of a motor is provided. During execution, this method first receives the three-phase stator current output from the three-phase inverter to the permanent magnet synchronous motor (PMSM) for the current cycle. The three-phase stator current is generated by an excitation signal produced from a rotating high-frequency voltage signal input in a two-phase stationary coordinate system. Secondly, the three-phase stator current is band-pass filtered based on the transfer function determined by the electrical angular frequency of the PMSM in the previous cycle to obtain the high-frequency component. Then, the high-frequency component is low-pass filtered in a high-frequency synchronous rotating coordinate system to obtain the corresponding low-frequency component. Finally, the rotor position of the PMSM in the current cycle is determined based on this low-frequency component and the rotor position of the PMSM in the previous cycle. Based on this method, the three-phase stator current can be band-pass filtered according to the electrical angular frequency of the PMSM in the previous cycle. This allows the transfer function of the band-pass filter to be adjusted during the operation of the PMSM, making the center frequency of the band-pass filter adaptively change with the electrical angular frequency of the PMSM in the previous cycle, thereby reducing the phase shift of the band-pass filter and thus reducing the error in the rotor position information.

[0006] In one possible implementation, the process of bandpass filtering the three-phase stator current to obtain the high-frequency components of the three-phase stator current, based on the transfer function determined by the electrical angular frequency of the permanent magnet synchronous motor in the previous cycle, is as follows: First, the center frequency of the bandpass filter is determined based on the electrical angular frequency of the permanent magnet synchronous motor in the previous cycle, and at least one or more of the following: the calculated frequency of the bandpass filter and the frequency of the rotating high-frequency voltage signal. Then, the three-phase stator current is bandpass filtered based on the center frequency, and at least one or more of the following: the passband bandwidth of the bandpass filter and the transfer function determined by the calculated frequency of the bandpass filter, to obtain the high-frequency components of the three-phase stator current. Based on this, the center frequency and transfer function of the bandpass filter can be adaptively adjusted according to the above parameters, thereby reducing the phase shift caused by the bandpass filter.

[0007] In one possible implementation, the above transfer function is calculated as follows:

[0008]

[0009] Where, k B k T k C To simplify the calculation of intermediate process variables, their expressions are as follows:

[0010]

[0011]

[0012] In the above formula, f s The calculated frequency for the bandpass filter is represented by BW; ω represents the passband bandwidth of the bandpass filter.h ω represents the frequency of the rotating high-frequency voltage signal. E Ω0 represents the electrical angular frequency of the permanent magnet synchronous motor in one cycle; Ω0 represents the center frequency of the bandpass filter.

[0013] In one possible implementation, the step of determining the rotor position of the permanent magnet synchronous motor (PMSM) in the current cycle based on the aforementioned low-frequency components and the rotor position of the PMSM in the previous cycle is performed as follows: First, the angular error value of the PMSM is determined based on the low-frequency components and the rotor position of the PMSM in the previous cycle. Then, phase-locked loop processing is performed based on this angular error value to determine the electrical angular frequency of the PMSM in the current cycle. Finally, the rotor position of the PMSM in the current cycle is determined based on this electrical angular frequency. This method allows for a more accurate determination of the rotor position of the PMSM in the current cycle.

[0014] In one possible implementation, the process of low-pass filtering the aforementioned high-frequency components in a high-frequency synchronous rotating coordinate system to obtain the corresponding low-frequency components can be performed as follows: First, the coordinate transformation matrix of the negative-order high-frequency synchronous rotating coordinate system can be determined based on the frequency of the rotating high-frequency voltage signal. Then, the corresponding signal component is determined based on the coordinate transformation matrix and the high-frequency components. Finally, the signal component is low-pass filtered to obtain the corresponding low-frequency component. Through this method, the coordinate transformation matrix of the negative-order high-frequency synchronous rotating coordinate system can be adjusted according to the frequency of the rotating high-frequency voltage signal, making the obtained signal components more accurate.

[0015] Secondly, a motor rotor position detection device is provided, comprising a receiving module, a bandpass filter module, a low-frequency component determination module, and a rotor position determination module. The receiving module receives the three-phase stator current output from the three-phase inverter to the permanent magnet synchronous motor (PMSM) in the current cycle. The three-phase stator current is generated by an excitation signal generated by a chip based on a rotating high-frequency voltage signal input in a two-phase stationary coordinate system. The bandpass filter module performs bandpass filtering on the three-phase stator current received by the receiving module based on the transfer function determined by the electrical angular frequency of the PMSM in the previous cycle, obtaining the high-frequency component of the three-phase stator current. The low-frequency component determination module performs low-pass filtering on the high-frequency component obtained by the bandpass filter module in a high-frequency synchronous rotating coordinate system, obtaining the corresponding low-frequency component. The rotor position determination module determines the rotor position of the PMSM in the current cycle based on the low-frequency component obtained by the low-frequency component determination module and the rotor position of the PMSM in the previous cycle.

[0016] In one possible implementation, the bandpass filter module performs the following steps: First, based on the electrical angular frequency of the permanent magnet synchronous motor in the previous cycle, and at least one or more of the following: the calculated frequency of the bandpass filter and the frequency of the rotating high-frequency voltage signal, the center frequency of the bandpass filter is determined. Then, based on the aforementioned center frequency, and at least one or more of the following: the passband bandwidth of the bandpass filter and the transfer function determined by the calculated frequency of the bandpass filter, the three-phase stator current is bandpass filtered to obtain the high-frequency components in the three-phase stator current.

[0017] In one possible implementation, the transfer function is calculated as follows:

[0018]

[0019] Where, k B k T k C To simplify the calculation of intermediate process variables, their expressions are as follows:

[0020]

[0021]

[0022] In the above formula, f s The calculated frequency for the bandpass filter is represented by BW; ω represents the passband bandwidth of the bandpass filter. h ω represents the frequency of the rotating high-frequency voltage signal. E Ω0 represents the electrical angular frequency of the permanent magnet synchronous motor in one cycle; Ω0 represents the center frequency of the bandpass filter.

[0023] In one possible implementation, the rotor position determination module includes an angle error calculation submodule and a rotor position calculation submodule. The angle error calculation submodule determines the angle error value of the permanent magnet synchronous motor based on the low-frequency components and the rotor position of the permanent magnet synchronous motor in the previous cycle. The rotor position calculation submodule performs phase-locked loop processing based on the angle error value to determine the electrical angular frequency of the permanent magnet synchronous motor in the current cycle; and determines the rotor position of the permanent magnet synchronous motor in the current cycle based on this electrical angular frequency.

[0024] In one possible implementation, the aforementioned low-frequency component determination module includes a coordinate transformation submodule and a low-pass filtering submodule. The coordinate transformation submodule determines the coordinate transformation matrix of the negative-order high-frequency synchronous rotating coordinate system based on the frequency of the rotating high-frequency voltage signal, and determines the corresponding signal component based on the coordinate transformation matrix and the high-frequency component. The low-pass filtering submodule performs low-pass filtering on this signal component to obtain the corresponding low-frequency component.

[0025] Thirdly, a computer-readable storage medium is provided that stores computer program instructions, which, when executed by a processor, can implement the method in any possible implementation of the first aspect described above.

[0026] Fourthly, a chip is provided, comprising a processor and a memory. The memory stores computer program instructions; when executed by the processor, the computer program instructions implement the method in any of the possible implementations of the first aspect described above.

[0027] Fifthly, a motor control system is provided, which includes a controller and a chip as described in the third aspect above, coupled to the controller.

[0028] In a sixth aspect, a vehicle is provided, the vehicle including a permanent magnet synchronous motor and a motor control system as described in the fifth aspect above, coupled to the permanent magnet synchronous motor.

[0029] In a seventh aspect, a computer program product is provided, which, when executed by a processor, implements the method in any possible implementation of the first aspect described above.

[0030] The technical effects that can be achieved by the second to seventh aspects mentioned above can be found in the first aspect mentioned above, and will not be repeated here. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of a motor control system provided in an embodiment of this application;

[0032] Figure 2 A schematic flowchart of a motor rotor position detection method provided in an embodiment of this application;

[0033] Figure 3 This is a schematic diagram of the structure of a motor rotor position detection device provided in an embodiment of this application;

[0034] Figure 4 This is a schematic diagram of the structure of a chip provided in an embodiment of this application;

[0035] Figure 5 This is a schematic diagram of the structure of a motor control system provided in an embodiment of this application;

[0036] Figure 6 This is a structural schematic diagram of a vehicle provided in an embodiment of this application. Detailed Implementation

[0037] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0038] In the embodiments of this application, the terms "first" and "second" are used to distinguish identical or similar items with substantially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, nor do they necessarily imply difference. Furthermore, in the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is being used as an example, illustration, or description. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner for ease of understanding.

[0039] Furthermore, in this application, directional terms such as "upper," "lower," "left," "right," "horizontal," and "vertical" are defined relative to the indicated placement of the components in the accompanying drawings. It should be understood that these directional terms are relative concepts, used for relative description and clarification, and can change accordingly depending on the placement of the components in the accompanying drawings.

[0040] In this application, unless otherwise expressly specified and limited, the term "connection" shall be interpreted broadly. For example, "connection" may be a fixed connection, a detachable connection, or an integral part; it may be a direct connection or an indirect connection through an intermediate medium.

[0041] The present invention will now be described in detail with reference to the accompanying drawings and embodiments:

[0042] Permanent magnet synchronous motors (PMSMs) are widely used in various fields due to their advantages such as high power density, high efficiency, and relatively simple control. Controlling a PMSM requires knowing the rotor position information. Currently, position sensors, such as rotary transformers and photoelectric encoders, are generally used to obtain the rotor position. However, position sensors are costly and have poor adaptability to complex environments. Therefore, using sensorless control algorithms to replace position sensors is an effective solution.

[0043] In sensorless control algorithms, the rotating high-frequency injection method is a commonly used approach for sensorless control of permanent magnet synchronous motors (PMSMs). This method is typically used for zero-speed start-up and low-speed operation. Specifically, the rotating high-frequency injection method first injects a rotating high-frequency voltage into the two-phase stationary coordinate system of the PMSM, and then generates a high-frequency response current carrying rotor position information based on the PMSM's salient polarity. Next, by extracting this current and calculating the rotor position information within it, sensorless control of the motor is achieved based on this rotor position information.

[0044] like Figure 1 As shown, the control system corresponding to the sensorless control algorithm of the permanent magnet synchronous motor typically includes a controller 110; a chip 120 coupled to the controller 110; a three-phase inverter 140 coupled to the chip 120; and a permanent magnet synchronous motor 150 coupled to the three-phase inverter 140. The permanent magnet synchronous motor 150 is equipped with a current sampling circuit. The chip 120 mainly includes a speed regulation module 121, a q-axis current regulation module 122, a d-axis current regulation module 123, an inverse coordinate transformation module 124, a rotating high-frequency voltage injection module 125, an SVPWM modulation module 126, a coordinate transformation module 127, a bandpass filter module 128, a synchronous rotating coordinate system transformation module 129, a low-pass filter module 130, and a phase-locked loop module 131. The coordinate transformation module 127 takes the three-phase stator current of the motor as input and outputs the d-axis feedback current and q-axis feedback current of the motor. The speed regulation module 121 takes as input the difference between the given electrical angular frequency command and the speed output by the phase-locked loop module in the previous calculation cycle, and outputs a q-axis current command. The d-axis current regulation module 123 takes as input the difference between the d-axis current command and the d-axis feedback current, and outputs a d-axis voltage command; the q-axis current regulation module 122 takes as input the difference between the q-axis current command and the q-axis feedback current, and outputs a q-axis voltage command. The inverse coordinate transformation module 124 takes as input the d- and q-axis voltage commands of the permanent magnet synchronous motor, and outputs the α- and β-axis voltage commands of the permanent magnet synchronous motor. The rotating high-frequency voltage injection module 125 injects a rotating high-frequency voltage signal superimposed on the α- and β-axis voltage commands, and outputs the voltages injected into the α- and β-axis axes. The SVPWM modulation module 126 takes as input the voltages injected into the α- and β-axis axes, and outputs six-channel PWM duty cycle commands. The three-phase inverter module 140 converts the six-channel PWM duty cycle commands output by the control system software into actual hardware actions, and outputs three-phase voltages. The permanent magnet synchronous motor 150 includes the motor body and a current sampling circuit. The input to the motor body is a three-phase voltage, and the output of the current sampling circuit is the three-phase current sample value I. A I B I C The input to the bandpass filter module 128 is the sampled value I of the three-phase stator current. A I B I C The output is I A High-frequency component I AH I B High-frequency component I BH and I C High-frequency component I CH The synchronous rotating coordinate system transformation module 129 receives the high-frequency component I from the three-phase stator current as input. AH I BH I CH The output is the high-frequency component of current I. HD IHQ The low-pass filter module 130 receives the high-frequency current component I as input. HD I HQ The output is the filtered current component. The input to the phase-locked loop module 131 is the transformed negative-sequence high-frequency current component information I. HDL I HQL The output is the estimated electrical angular frequency (also known as rotational speed or electrical angular velocity) and the motor rotor angle (i.e., the motor rotor position).

[0045] In the rotating high-frequency injection method, the bandpass and low-pass filtering processes cause a phase shift in the current signal, leading to errors in the extracted rotor position information and thus reducing motor efficiency. The phase shift caused by the bandpass filtering process for extracting the negative-sequence high-frequency current is most significant under high load conditions. Bandpass filtering is typically designed with the injection frequency as the center frequency and has fixed parameters; however, when the frequency of the negative-sequence high-frequency current changes with the motor speed, a noticeable phase shift occurs.

[0046] To solve the above problems, such as Figure 2 As shown, this application embodiment provides a method for detecting the position of a motor rotor, which is executed in the aforementioned chip. The specific process is as follows:

[0047] S201. Inject a rotating high-frequency voltage signal V into the two-phase stationary coordinate system of the permanent magnet synchronous motor. hα V hβ .

[0048] Among them, the injected rotating high-frequency voltage signal V hα V hβ The expression is:

[0049] V hα =U h cos(ω h t);

[0050] V hβ =U h sin(ω h t);

[0051] In the above formula, ω h U is the frequency of the injected rotating high-frequency voltage signal; h This indicates the amplitude of the injected rotating high-frequency voltage signal.

[0052] In one possible implementation, a rotating high-frequency voltage signal V is injected in a two-phase stationary coordinate system. hα V hβ The output can be generated by a voltage generator, and the high-frequency voltage signal V can be rotated. hα V hβPre-configuration can be performed according to the actual control requirements of the permanent magnet synchronous motor, and this application embodiment does not impose specific limitations on this.

[0053] S202. Receive the three-phase stator current output from the three-phase inverter to the permanent magnet synchronous motor in the current cycle.

[0054] The three-phase stator current of the permanent magnet synchronous motor can be obtained by sampling through the current sampling circuit set on the permanent magnet synchronous motor and then transmitted to the chip.

[0055] For example, the expression for the three-phase stator current of the permanent magnet synchronous motor in a two-phase stationary coordinate system is as follows:

[0056]

[0057] In the above formula, i α i β i represents the current in a two-phase stationary coordinate system; αH i βH Represents the high-frequency response current component; i αB i βB L represents the fundamental frequency current component of the motor; d L q The inductance of the d-axis of the permanent magnet synchronous motor; ω E ω is the electrical angular frequency of the permanent magnet synchronous motor in one cycle; h U is the frequency of the injected rotating high-frequency voltage signal; h This indicates the amplitude of the injected rotating high-frequency voltage signal.

[0058] The three stator currents obtained using the above method, in a two-phase stationary coordinate system, each contain three frequency components: the fundamental frequency current component during normal operation of the permanent magnet synchronous motor, the positive-sequence high-frequency current component with the same frequency as the injected rotating high-frequency voltage signal, and the negative-sequence high-frequency current component related to the frequency of the injected rotating high-frequency voltage signal and the electrical angular frequency of the permanent magnet synchronous motor. The negative-sequence high-frequency current component contains the rotor position information needed to indicate the rotor position and is therefore a valid signal. The other two components are useless signals and need to be filtered out.

[0059] S203. The three-phase stator current is bandpass filtered based on the transfer function determined by the electrical angular frequency of the previous cycle of the permanent magnet synchronous motor to obtain the high-frequency components in the three-phase stator current.

[0060] In one implementation, the center frequency of the bandpass filter can be determined based on the electrical angular frequency of the permanent magnet synchronous motor in the previous cycle, and one or more of at least two of the following: the calculated frequency of the bandpass filter and the frequency of the rotating high-frequency voltage signal. Then, based on the center frequency and one or more of the following: the passband bandwidth of the bandpass filter and the calculated frequency of the bandpass filter, the transfer function determined is used to bandpass filter the three-phase stator current to obtain the high-frequency components in the three-phase stator current.

[0061] For example, when determining the center frequency of the bandpass filter, it can be determined based on the electrical angular frequency of the permanent magnet synchronous motor in the previous cycle and the frequency of the rotating high-frequency voltage signal; or, it can be determined based on the electrical angular frequency of the permanent magnet synchronous motor in the previous cycle, the calculated frequency of the bandpass filter, and the frequency of the rotating high-frequency voltage signal; or, it can be determined based on the electrical angular frequency of the permanent magnet synchronous motor in the previous cycle and the calculated frequency of the bandpass filter. When determining the transfer function, the three-phase stator current can be bandpass filtered based on the transfer function determined by the center frequency and the passband bandwidth of the bandpass filter; or, it can be bandpass filtered based on the transfer function determined by the center frequency and the calculated frequency of the bandpass filter; or, it can be bandpass filtered based on the transfer function determined by the center frequency, the passband bandwidth of the bandpass filter, and the calculated frequency of the bandpass filter.

[0062] The bandpass filter has the same center frequency as the negative-sequence high-frequency current component and a gain coefficient of 1. This bandpass filtering process results in a 0° phase shift for the negative-sequence high-frequency current component, with no amplitude attenuation. For other frequencies, it exhibits varying degrees of amplitude attenuation, effectively filtering out the fundamental frequency current component and some positive-sequence high-frequency current components, resulting in a filtered signal containing only positive and negative-sequence high-frequency components.

[0063] For example, the transfer function in the bandpass filtering process can be expressed as:

[0064]

[0065] Where, k B k T k C To simplify the calculation of intermediate process variables, their expressions are as follows:

[0066]

[0067]

[0068] In the above formula, f s The calculated frequency for the bandpass filter is represented by BW; ω represents the passband bandwidth of the bandpass filter. hω represents the frequency of the rotating high-frequency voltage signal. E Ω0 represents the electrical angular frequency of the permanent magnet synchronous motor in one cycle; Ω0 represents the center frequency of the bandpass filter.

[0069] S204. Perform low-pass filtering on the high-frequency components in a high-frequency synchronous rotating coordinate system to obtain the corresponding low-frequency components.

[0070] In one possible implementation, the above process can be performed as follows:

[0071] S2041. Determine the coordinate transformation matrix of the high-frequency synchronous rotating coordinate system based on the frequency of the rotating high-frequency voltage signal.

[0072] The coordinate transformation matrix is ​​expressed as follows:

[0073]

[0074] Where, ω h The frequency of the injected rotating high-frequency voltage signal is denoted as . This coordinate transformation matrix can be adaptively adjusted according to the frequency of the rotating high-frequency voltage signal.

[0075] S2042. Determine the corresponding signal components based on the coordinate transformation matrix and the high-frequency components.

[0076] After bandpass filtering, the high-frequency component I in the stator current AH I BH I CH It contains two high-frequency current components with similar frequencies: positive-sequence and negative-sequence. To facilitate filtering design, the frequencies of the two current components need to be separated through coordinate transformation. Because the negative-sequence high-frequency current component is the effective signal, this high-frequency synchronous rotating coordinate system is a negative-sequence high-frequency synchronous rotating coordinate system.

[0077] For example, after transformation, the signal component I of the current in a negative-sequence high-frequency synchronous rotating coordinate system is obtained. HD I HQ The expression is:

[0078]

[0079] In the above formula, I HA I LA These represent the amplitudes of the two frequency current components after transformation.

[0080] S2043. Perform low-pass filtering on the signal components to obtain the corresponding low-frequency components.

[0081] In the above implementation process, the output I of step S2042 HD I HQThe signal contains two frequencies: a low-frequency component that is twice the electrical angular frequency of the permanent magnet synchronous motor, and a high-frequency component that is twice the frequency of the injected rotating high-frequency voltage signal. The low-frequency component, obtained by transforming the negative-sequence high-frequency current component, is a valid signal; the high-frequency component, obtained by transforming the positive-sequence high-frequency current component, is a useless signal and needs to be filtered out.

[0082] For example, in a typical permanent magnet synchronous motor, the amplitude of the low-frequency component is smaller than that of the high-frequency component, meaning the amplitude of the useful signal is smaller than that of the useless signal. In step S203, the bandpass filter has limited attenuation effect on the useless signal, primarily due to the limited attenuation of the amplitude of the positive-sequence high-frequency current component. Especially when the permanent magnet synchronous motor is in its initial positioning state, the useless signal of the positive-sequence high-frequency current component has the same frequency as the effective signal of the negative-sequence high-frequency current component, and the bandpass filter has no attenuation effect on the amplitude of the positive-sequence high-frequency current component. Therefore, after the coordinate transformation in step S2042, a first-order low-pass filter is needed to further attenuate the amplitude of the useless high-frequency signal.

[0083] Considering the inherent phase shift problem of low-pass filtering and the different attenuation requirements for unwanted signals in different states, in the initial positioning state of a permanent magnet synchronous motor, the low-frequency component is a DC component with zero frequency, while the positive-sequence high-frequency current component has a large amplitude. Therefore, the cutoff frequency f during low-pass filtering can be adjusted. L1 The frequency is set to be much lower than that of the high-frequency components. In the closed-loop operation of the permanent magnet synchronous motor, the bandpass filter in step S203 already has a certain attenuation effect on the positive-sequence high-frequency current components. Therefore, the cutoff frequency f during low-pass filtering is set to... L2 Set the frequency to be close to that of the high-frequency components to reduce the phase shift of the low-frequency components.

[0084] S205. Determine the rotor position of the permanent magnet synchronous motor in the current cycle based on the low-frequency components and the rotor position of the permanent magnet synchronous motor in the previous cycle.

[0085] The specific execution process of the above process is as follows:

[0086] S2051. Determine the angular error value of the permanent magnet synchronous motor based on the low-frequency component and the rotor position of the permanent magnet synchronous motor in the previous cycle.

[0087] The formula for calculating the rotor position error value ε is:

[0088] ε=-I HDL *sinθ′+I HQL *cosθ′;

[0089] In the formula, θ′ represents the rotor position output by the phase-locked loop in the previous calculation cycle; I HDL For I HD The low-frequency component obtained after low-pass filtering; I HQL For I HQThe low-frequency component obtained after low-pass filtering.

[0090] S2052. Perform phase-locked processing on the angle error value to determine the electrical angular frequency of the permanent magnet synchronous motor in the current cycle.

[0091] Among them, the electrical angular frequency ω of the permanent magnet synchronous motor in the current cycle e The calculation method is as follows:

[0092] ω e =k p ε+k i ∫εdt;

[0093] In the above formula, k p k is the proportional gain of the phase-locked loop; i Integral calculation coefficients of phase-locked loop.

[0094] S2053. Determine the rotor position of the permanent magnet synchronous motor in the current cycle based on the above-mentioned electrical angular frequency.

[0095] The rotor position of the permanent magnet synchronous motor in the current cycle is calculated as follows:

[0096] θ=(∫ω e dt-π / 2) / 2;

[0097] In the above formula, θ represents the rotor position of the permanent magnet synchronous motor in the current cycle; ω e This indicates the electrical angular frequency of the permanent magnet synchronous motor in the current cycle.

[0098] It is understood that the methods and / or steps implemented by the motor rotor position detection device in the above embodiments can also be implemented by components (e.g., chips or circuits) that can be used in the motor rotor position detection device.

[0099] It is understood that, in order to achieve the above-mentioned functions, the motor rotor position detection device includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily recognize that, based on the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein, the embodiments of this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0100] This application embodiment can divide the motor rotor position detection device into functional modules according to the above method embodiment. For example, each function can be divided into its own functional module, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware or as a software functional module. It should be noted that the module division in this application embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0101] like Figure 3 As shown in the illustration, this application also provides a motor rotor position detection device 300, which includes a receiving module 310, a bandpass filter module 320, a low-frequency component determination module 330, and a rotor position determination module 340. The receiving module 310 receives the three-phase stator current output from the three-phase inverter to the permanent magnet synchronous motor in the current cycle. The three-phase stator current is generated by an excitation signal generated from a rotating high-frequency voltage signal input in a two-phase stationary coordinate system. The bandpass filter module 320 performs bandpass filtering on the three-phase stator current received by the receiving module 310 based on the transfer function determined by the electrical angular frequency of the permanent magnet synchronous motor in the previous cycle, obtaining the high-frequency component of the three-phase stator current. The low-frequency component determination module 330 performs low-pass filtering on the high-frequency component obtained by the bandpass filter module 320 in a high-frequency synchronous rotating coordinate system, obtaining the corresponding low-frequency component. The rotor position determination module 340 can determine the rotor position of the permanent magnet synchronous motor in the current cycle based on the low-frequency component obtained by the low-frequency component determination module 330 and the rotor position of the permanent magnet synchronous motor in the previous cycle.

[0102] In one possible implementation, the bandpass filter module 320 can determine the center frequency of the bandpass filter based on the electrical angular frequency of the permanent magnet synchronous motor in the previous cycle, the calculated frequency of the chip, and the frequency of the rotating high-frequency voltage signal. Then, the three-phase stator current is bandpass filtered based on the center frequency, the passband bandwidth of the bandpass filter, and the transfer function determined by the calculated frequency of the chip to obtain the high-frequency components in the three-phase stator current. The transfer function is expressed as:

[0103]

[0104] Where, k B k T k C To simplify the calculation of intermediate process variables, their expressions are as follows:

[0105]

[0106]

[0107] In the above formula, fs The calculated frequency for the bandpass filter is represented by BW; ω represents the passband bandwidth of the bandpass filter. h ω represents the frequency of the rotating high-frequency voltage signal. E Ω0 represents the electrical angular frequency of the permanent magnet synchronous motor in one cycle; Ω0 represents the center frequency of the bandpass filter.

[0108] In one possible implementation, the rotor position determination module 340 may include an angle error calculation submodule 341 and a rotor position calculation submodule 342. The angle error calculation submodule 341 determines the angle error value of the permanent magnet synchronous motor based on the low-frequency component and the rotor position of the permanent magnet synchronous motor in the previous cycle. The rotor position calculation submodule 342 performs phase-locked loop processing based on the angle error value to determine the electrical angular frequency of the permanent magnet synchronous motor in the current cycle; and determines the rotor position of the permanent magnet synchronous motor in the current cycle based on the electrical angular frequency.

[0109] The angle error calculation submodule 341 can be implemented through an algorithm program. The rotor position calculation submodule 342 can be executed through a phase-locked loop (PLL), which can be implemented through an algorithm program or through logic circuits; this embodiment does not impose specific limitations on this.

[0110] It is understood that the calculation method of the angle error calculation module can refer to the method in S2051; the calculation method of the rotor position calculation module can refer to the method in S2052 to S2053. The embodiments of this application will not be described in detail here.

[0111] In one possible implementation, the low-frequency component determination module 330 includes a coordinate transformation submodule 331 and a low-pass filtering submodule 332. The coordinate transformation submodule 331 can determine the coordinate transformation matrix of the high-frequency synchronous rotating coordinate system based on the frequency of the rotating high-frequency voltage signal, and determine the corresponding signal component based on the coordinate transformation matrix and the high-frequency component. The low-pass filtering submodule 332 can perform low-pass filtering on the signal component to obtain the corresponding low-frequency component.

[0112] The coordinate transformation submodule 331 can be implemented using an algorithm program. The low-pass filter submodule 332 can be implemented using an algorithm program or a logic circuit; this embodiment does not impose specific limitations on this.

[0113] Understandably, the coordinate transformation module's transformation process can be implemented using the methods described in S2041 to S2042. The low-pass filter module can use a first-order low-pass filter. However, considering the inherent phase shift problem of low-pass filtering and the different attenuation requirements for useless signals in different states, in the initial positioning state of the permanent magnet synchronous motor, the low-frequency component is a DC component with zero frequency, while the positive-sequence high-frequency current component has a large amplitude. Therefore, the cutoff frequency f during low-pass filtering can be adjusted. L1The frequency is set to be much lower than that of the high-frequency components. In the closed-loop operation of the permanent magnet synchronous motor, the bandpass filter in step S203 already has a certain attenuation effect on the positive-sequence high-frequency current components. Therefore, the cutoff frequency f during low-pass filtering is set to... L2 Set the frequency to be close to that of the high-frequency components to reduce the phase shift of the low-frequency components.

[0114] In one possible implementation, such as Figure 4 As shown, this application embodiment also provides a chip 400, which includes a processor 410 and a memory 420. The memory 420 stores computer program instructions; when executed by the processor 410, these computer program instructions implement the motor rotor position detection method in any of the above possible implementations. The processor 410 can be configured with, for example... Figure 1 The various functional modules shown are not described in detail in this embodiment of the application.

[0115] The processor 410 described above can be a central processing unit (CPU), a general-purpose processor, a network processor (NP), a digital signal processor (DSP), a microprocessor, a microcontroller, a programmable logic device (PLD), or any combination thereof. The processor 410 can also be other devices with processing functions, such as circuits, devices, or software modules, which are not limited in this application. The memory 420 described above can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of random access memory (RAM) are available, such as static RAM (SRAM), dynamic random access memory (DRAM), synchronous DRAM (SDRAM), double data rate synchronous DRAM (DDR SDRAM), enhanced synchronous DRAM (ESDRAM), synchronous linked DRAM (SLDRAM), and direct rambus RAM (DR RAM).

[0116] In one implementation scheme, such as Figure 5As shown in the figure, this application embodiment also provides a motor control system 500, which includes a controller 510 and the aforementioned chip 400 coupled to the controller 510. The motor control system 500 can be applied to vehicles, ships, aircraft, and other transportation vehicles equipped with permanent magnet synchronous motors; it can also be applied to household appliances and industrial equipment using permanent magnet synchronous motors, and this application embodiment does not impose specific limitations in this regard.

[0117] In one implementation scheme, such as Figure 6 As shown, this application embodiment provides a vehicle 600, which includes a permanent magnet synchronous motor 620, a three-phase inverter 610, and the aforementioned motor control system 500. The permanent magnet synchronous motor 620 is coupled to the output terminal of the three-phase inverter 610. A chip 400 in the motor control system 500 is coupled to both the permanent magnet synchronous motor 620 and the three-phase inverter 610. The controller 510 can output an electrical angular frequency command for the permanent magnet synchronous motor 620 to the chip 400. The chip 400 can control the three-phase inverter to output a three-phase voltage based on the input high-frequency rotating voltage and the aforementioned electrical angular frequency command; simultaneously, the chip 400 can also receive the three-phase stator current detected by the current sampling circuit on the permanent magnet synchronous motor 620, and output the rotor position of the permanent magnet synchronous motor 620 in the current cycle according to the aforementioned motor rotor position detection method. The modules of the aforementioned chip 400 can be referenced... Figure 1 The embodiments in this application will not be described in detail.

[0118] In one embodiment, this application also provides a computer-readable storage medium storing computer program instructions that, when executed by a processor, can implement the above-described motor rotor position detection method.

[0119] In one embodiment, this application also provides a computer program product that, when executed by a processor, can implement the above-described motor rotor position detection method.

[0120] Through the above description of the embodiments, those skilled in the art can clearly understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0121] In the embodiments provided in this application, it should be understood that the division of the modules in the above devices follows only a logical functional division. In actual implementation, they can be fully or partially integrated into a single physical entity, or they can be physically separated. Furthermore, the modules in the device can be implemented by a processor calling software; for example, the device includes a processor connected to a memory, which stores instructions. The processor calls the instructions stored in the memory to implement any of the above methods or to implement the functions of each module of the device. The processor can be, for example, the aforementioned general-purpose processor, central processing unit (CPU), or microprocessor, and the memory can be internal or external to the device. Alternatively, the modules in the device can be implemented as hardware circuits. The functionality of some or all modules can be achieved through the design of these hardware circuits, which can be understood as one or more processors. For example, in one implementation, the hardware circuit is an application-specific integrated circuit (ASIC). The functionality of some or all of the modules is achieved through the design of the logical relationships between the components within the circuit. In another implementation, the hardware circuit can be implemented using a programmable logic device (PLD), such as a field-programmable gate array (FPGA). This PLD can include a large number of logic gates, and the connection relationships between these logic gates are configured through configuration files, thereby achieving the functionality of some or all of the modules. All modules of the above device can be implemented through software calls by the processor.

[0122] Furthermore, the functional modules in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0123] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a readable storage medium. Based on this understanding, the technical solutions of the embodiments of this application, in essence, or the parts that contribute to the prior art, or all or part of the technical solutions, can be embodied in the form of a software product. This software product is stored in a storage medium and includes several instructions to cause a device, such as a microcontroller, chip, or processor, to execute all or part of the steps of the methods in the various embodiments of this application. The aforementioned computer storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0124] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method of detecting the position of a rotor of an electric machine, characterized in that, The method comprises the following steps: receiving three-phase stator currents of a permanent magnet synchronous motor in a current cycle, the three-phase stator currents being generated by exciting signals generated by a rotating high-frequency voltage signal input in a two-phase stationary coordinate system; determining a center frequency of a band-pass filtering according to an electrical angular frequency of the permanent magnet synchronous motor in a previous cycle, a calculation frequency of the band-pass filtering and a frequency of the rotating high-frequency voltage signal; band-pass filtering the three-phase stator currents according to a transfer function determined according to the center frequency, a passband bandwidth of the band-pass filtering and the calculation frequency of the band-pass filtering to obtain high-frequency components in the three-phase stator currents; the transfer function is calculated in the following manner: ； wherein k B , k T , k C is an intermediate process variable for simplifying the calculation, whose expression is: ； ； In the above formula, f s denotes the frequency of the bandpass filtered signal; BW is the passband bandwidth of the bandpass filter; ω h denotes the frequency of the rotating high-frequency voltage signal; ω E denotes the electrical angular frequency of one period on the permanent magnet synchronous machine; Ω0denotes the center frequency of the bandpass filter; low-pass filtering the high-frequency components in a high-frequency synchronous rotating coordinate system of a negative sequence to obtain corresponding low-frequency components; determining an angle error value of the permanent magnet synchronous motor according to the low-frequency components and a rotor position of the permanent magnet synchronous motor in a previous cycle; determining an electrical angular frequency of the permanent magnet synchronous motor in the current cycle by phase-locked processing of the angle error value; determining a rotor position of the permanent magnet synchronous motor in the current cycle according to the electrical angular frequency.

2. The method of claim 1, wherein, The low-pass filtering of the high-frequency components in the high-frequency synchronous rotating coordinate system of the negative sequence comprises the following steps: determining a coordinate transformation matrix of the high-frequency synchronous rotating coordinate system of the negative sequence according to the frequency of the rotating high-frequency voltage signal; determining corresponding signal components according to the coordinate transformation matrix and the high-frequency components; low-pass filtering the signal components to obtain the corresponding low-frequency components.

3. An electric motor rotor position detection device, characterized by comprising: The method comprises the following steps: a receiving module configured to receive three-phase stator currents of a permanent magnet synchronous motor in a current cycle, the three-phase stator currents being generated by exciting signals generated by a rotating high-frequency voltage signal input in a two-phase stationary coordinate system; a band-pass filtering module configured to determine a center frequency of a band-pass filtering according to an electrical angular frequency of the permanent magnet synchronous motor in a previous cycle, a calculation frequency of the band-pass filtering and a frequency of the rotating high-frequency voltage signal; and to band-pass filter the three-phase stator currents according to a transfer function determined according to the center frequency, a passband bandwidth of the band-pass filtering and the calculation frequency of the band-pass filtering to obtain high-frequency components in the three-phase stator currents; the transfer function is calculated in the following manner: ； wherein k B , k T , k C is an intermediate process variable for simplifying the calculation, whose expression is: ； ； In the above formula, f s denotes the frequency of the bandpass filtered signal; BW is the passband bandwidth of the bandpass filter; ω h denotes the frequency of the rotating high-frequency voltage signal; ω E denotes the electrical angular frequency of one period on the permanent magnet synchronous machine; Ω0denotes the center frequency of the bandpass filter; a low-frequency component determining module configured to low-pass filter the high-frequency components obtained by the band-pass filtering module in a high-frequency synchronous rotating coordinate system of a negative sequence to obtain corresponding low-frequency components; a rotor position determining module comprising an angle error calculating submodule and a rotor position calculating submodule; the angle error calculating submodule is configured to determine an angle error value of the permanent magnet synchronous motor according to the low-frequency components and a rotor position of the permanent magnet synchronous motor in a previous cycle; the rotor position calculating submodule is configured to determine an electrical angular frequency of the permanent magnet synchronous motor in the current cycle by phase-locked processing of the angle error value determined by the angle error calculating submodule; and to determine a rotor position of the permanent magnet synchronous motor in the current cycle according to the electrical angular frequency.

4. The motor rotor position detection apparatus according to claim 3, characterized by the low-frequency component determining module comprises a coordinate transformation submodule and a low-pass filtering submodule; The coordinate conversion submodule is configured to determine a coordinate transformation matrix of a synchronous rotating coordinate system according to a frequency of the rotating high-frequency voltage signal, and determine a corresponding signal component according to the coordinate transformation matrix and the high-frequency component; The low-pass filtering submodule is configured to perform low-pass filtering on the signal component determined by the coordinate conversion submodule to obtain a corresponding low-frequency component.

5. A computer readable storage medium, characterized in that, A computer program product is provided, which comprises computer program instructions stored in a computer readable storage medium, and the computer program instructions are executed by a processor to implement the method of claim 1 or 2.

6. A chip, characterized by A chip is provided, which comprises a processor and a memory, wherein the memory stores computer program instructions, and the computer program instructions are executed by the processor to implement the method of claim 1 or 2.

7. An electric motor control system characterized by comprising: A chip is provided, which comprises a controller and a chip as claimed in claim 6 coupled to the controller.

8. A vehicle characterized by comprising: An electric machine control system is provided, which comprises a permanent magnet synchronous motor and an electric machine control system as claimed in claim 7 coupled to the permanent magnet synchronous motor.

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