Motor rotor state observation method, observer and motor rotor angle estimation system

Abstract

The invention discloses a motor rotor state observation method and observer, and a motor rotor angle estimation system, and the observation method comprises the steps: obtaining a state parameter based on a current rotor state item and state parameter operation, and obtaining a voltage parameter based on a real-time sampling voltage and voltage parameter operation; integrating the current extension item, the state parameter item and the voltage parameter item to obtain an updated rotor state item, and updating the current rotor state item based on the updated rotor state item; and obtaining a current parameter item based on the real-time sampling current and the current parameter operation, integrating the current parameter item and the updated rotor state item to obtain an initial extension item, performing gain and amplitude limiting on the initial extension item based on the gain constant and the amplitude limiting parameter to obtain an updated extension item, and updating the current extension item based on the updated extension item. According to the invention, hardware acceleration in a rotor state acquisition process is realized, and the area of an electric control chip is reduced on the whole; and the dependence on high system frequency is also reduced, so that the operation power consumption of the system is reduced on the whole.

Description

Technical Field

[0001] The present invention relates to the technical field of motor control, and in particular to a motor rotor state observation method and observer, and a motor rotor angle estimation system. Background Art

[0002] In the field of motor control, how to accurately detect the motor rotor position is an extremely important technical difficulty, which is directly related to the selection of motor control strategy and the accuracy of motor control. In the prior art, there are two main ways to obtain the motor rotor position: direct method and indirect method: the direct method refers to obtaining the electronic rotor position by installing an external sensor, such as installing a Hall sensor, encoder, rotary transformer, etc. to obtain the motor rotor position, and then obtain the motor speed. This type of method requires external sensors for measurement, which undoubtedly increases the control cost; the indirect method does not require the installation of external sensors, and because of the advantages of low price and high reliability of position sensors, it is increasingly widely used in the field of motor control. The indirect method mainly estimates the motor rotor position by sampling various indicators during the rotation of the motor to complete the accurate control of the motor.

[0003] In the prior art, due to the complexity and diversity of the motor rotor angle estimation algorithm, designers usually use CPU or dedicated DSP processing unit to complete various complex algorithms. This setting undoubtedly puts forward higher requirements on the chip area cost and the chip system frequency. And the use of CPU or DSP to complete the estimation of the motor rotor position without position sensor not only causes the increase of chip area cost, but also puts forward higher requirements on the system frequency of the chip to which the motor rotor angle estimation is to be completed. For example, if a chip with a medium and low-end system frequency is used in the process of estimating the motor rotor position without position sensor, it will present problems such as too long time consumption and insufficient computing power when processing the algorithm in the field of electronic control. At the same time, the existing estimation method of the motor rotor position without position sensor also puts forward higher requirements on the professional ability of software personnel, which makes customers who are not familiar with the professional field of motor control need to spend more time in the early stage of entering the motor control field, which leads to low efficiency of the estimation of the motor rotor position without position sensor, and also relatively increases the cost of software development and maintenance. Summary of the invention

[0004] The purpose of this application is to provide a motor rotor state observation method and observer, and a motor rotor angle estimation system, which are used to solve the problem that the existing motor rotor angle estimation algorithms are complex and diverse, which puts high requirements on the chip area cost and chip system frequency, and at the same time puts high requirements on the professional capabilities of software personnel.

[0005] In a first aspect, the present application provides a method for observing a motor rotor state, comprising:

[0006] Whenever the latest real-time sampled voltage and real-time sampled current of the state observer to be detected are obtained:

[0007] The state parameter items are obtained based on the current rotor state item and the state parameter calculation, and the voltage parameter items are obtained based on the latest real-time sampled voltage and voltage parameter calculation, the current extension item, the state parameter item and the voltage parameter item are integrated to obtain an updated rotor state item, and the current rotor state item is updated based on the updated rotor state item;

[0008] And based on the latest real-time sampled current and current parameter calculation, the current parameter item is obtained, the current parameter item and the updated rotor state item are integrated to obtain an initial extension item, the initial extension item is gained based on a gain constant, and the initial extension item after gain is limited based on a limiting parameter to obtain an updated extension item, and the current extension item is updated based on the updated extension item.

[0009] In one embodiment of the present application, the current rotor state item and state parameter are obtained by multiplication to obtain the state parameter item; the latest real-time sampled voltage and voltage parameter are obtained by multiplication to obtain the voltage parameter item; the latest real-time sampled current and current parameter are obtained by multiplication to obtain the current parameter item.

[0010] In one embodiment of the present application, before the step of acquiring the latest real-time sampled voltage and real-time sampled current of the state observer to be detected, the following steps are also included:

[0011] Acquire an original mathematical model of the state observer to be detected, and perform discrete variation on the original mathematical model to obtain a conversion mathematical model of a preset form;

[0012] Based on the conversion mathematical model, an initial rotor state item, an initial expansion item and a conventional parameter group are obtained, wherein the conventional parameter group includes a state parameter, a voltage parameter, a current parameter, a gain constant and a limiting parameter.

[0013] In one embodiment of the present application, the conversion mathematical model expression in the preset form is:

[0014]

[0015] Among them, X n To update the rotor state term, P s is the state parameter, X n-1 is the current rotor state item, P v is the voltage parameter, V is the latest real-time sampling voltage, Ex n-1 is the current expansion item, M is the limit parameter, K is the constant gain, P i is the current parameter, I is the latest real-time sampling current, Exn is to update the extension item, and M is the limiting parameter.

[0016] In a second aspect, the present application provides a motor rotor state observer, comprising a data storage unit and a state observation process unit connected;

[0017] The data storage unit is used to store the real-time sampled voltage and real-time sampled current of the state observer to be detected, and is used to store the rotor state item, the extended item and the conventional parameter group;

[0018] The state observation process unit includes a rotor state item process circuit and an extension item process circuit;

[0019] The rotor state item flow circuit is used to execute the rotor state item update process in the motor rotor state observation method every time a group of real-time sampled voltages and real-time sampled currents of the state observer to be detected in the data storage unit are read;

[0020] The extended item flow circuit is used to execute the extended item update process in the motor rotor state observation method each time a group of real-time sampled voltages and real-time sampled currents of the state observer to be detected in the data storage unit are read.

[0021] In one embodiment of the present application, the rotor state item flow circuit includes a first logic multiplier, a second logic multiplier, a first logic adder / subtractor, and a second logic adder / subtractor;

[0022] The state parameter and the rotor state item are both input into the first logic multiplier, the voltage parameter and the real-time sampling voltage are input into the second logic multiplier, the output end of the first logic multiplier and the output end of the second logic multiplier are both connected to the input end of the first logic adder / subtractor, the extension item is input into the second logic adder / subtractor, the output end of the first logic adder / subtractor is also connected to the input end of the second logic adder / subtractor, and the output end of the second logic adder / subtractor outputs the updated rotor state item.

[0023] In one embodiment of the present application, the state observation process unit also includes a first arithmetic mechanism, the first logic multiplier and the second logic multiplier are realized by time-sharing multiplexing the logic multipliers in the first arithmetic mechanism, and the first logic adder / subtractor and the second logic adder / subtractor are realized by time-sharing multiplexing the logic adder / subtractors in the first arithmetic mechanism.

[0024] In one embodiment of the present application, the extended term flow circuit includes a third logic multiplier, a third logic adder / subtractor, a fourth logic multiplier, and a virtual limiter;

[0025] The current parameter and the real-time sampled current are both input into the third logic multiplier, the updated rotor state item is input into the third logic adder / subtractor, the output of the third logic multiplier is also connected to the input of the third logic adder / subtractor, the constant gain is input into the fourth logic multiplier, the output of the third logic adder / subtractor is connected to the input of the fourth logic multiplier, the limiting parameter is input into the virtual limiter, the output of the fourth logic multiplier is connected to the input of the virtual limiter, and the output of the virtual limiter outputs the updated expansion item.

[0026] In one embodiment of the present application, the state observation process unit also includes a second arithmetic mechanism, the third logic multiplier is implemented by the logic multiplier in the second arithmetic mechanism, the third logic adder / subtractor and the fourth logic multiplier are implemented by time-sharing multiplexing the logic adder / subtractor in the second arithmetic mechanism, and the virtual limiter is implemented by the limiter in the second arithmetic mechanism.

[0027] In a third aspect, the present application provides a motor rotor angle estimation system, comprising a central processing unit, a motor rotor state observer, a low-pass filter and an angle estimation module connected in sequence, wherein the central processing unit is also connected to the angle estimation module so that the estimated angle obtained by the angle estimation module is fed back to the central processing unit;

[0028] Wherein, the motor rotor state observer is the motor rotor state observer mentioned above.

[0029] In one embodiment of the present application, a motor rotor state software observer is stored in the central processing unit, and the central processing unit is also connected to the low-pass filter.

[0030] In one embodiment of the present application, the central processing unit stores a motor rotor state software observer and a low-pass software filter, and the central processing unit is also connected to the angle estimation module.

[0031] In an embodiment of the present application, the angle estimation module is an angle estimation module based on PLL angle estimation or an angle estimation module based on inverse tangent.

[0032] Compared with the prior art, one or more embodiments of the above scheme may have the following advantages or beneficial effects:

[0033] 1. The motor rotor state observation method provided by the embodiment of the present invention sets an extension item in the motor rotor state parameter, and sets the motor rotor state determination form in combination with the extension item, and then obtains the motor rotor state information in all states in a recursive manner, thereby solving the problem that the existing motor rotor state observation method cannot meet the diverse and complex motor rotor conditions. The extension parameter can be applied to both simple and certain linear systems and complex and uncertain nonlinear systems, which not only improves the calculation efficiency of the system, but also meets the customer's diverse expansion needs, leaving customers with a high degree of freedom.

[0034] 2. The motor rotor state observer provided by the embodiment of the present invention realizes parameter acquisition by setting the parameters and extension items necessary for obtaining the motor rotor state, and obtains the rotor state through the state observation process unit circuit structure based on the acquired parameters, thereby realizing hardware acceleration of the rotor state acquisition process.

[0035] 3. Adding pipelines and multiplexing methods to the state observation process unit saves the data signal processing process for the entire electronic control chip, thereby reducing the area of ​​the electronic control chip as a whole, reducing the electronic control calculation time, and reducing the dependence on high system frequency, further reducing the overall system operating power consumption.

[0036] 4. The motor rotor angle estimation system provided in the embodiment of the present invention realizes hardware acceleration of the most complex angle estimation algorithm in the field of electronic control, making it possible for chips with mid- and low-end system frequencies to complete complex electronic control at lower frequencies, reducing the dependence of motor control chips on system frequency, and at the same time reducing the difficulty of algorithm development in the field of electronic control, solving the problems of high software development difficulty and high maintenance cost, and expanding the user group.

[0037] 5. The motor rotor angle estimation system provided by the embodiment of the present invention supports hardware integration and software algorithm scalability, which releases part of the CPU resources, improves the speed of motor rotor position estimation, and improves the overall performance of the chip. In addition, the user can also choose to use the PLL-based angle estimation module or the arctangent-based angle estimation module through the central processor according to their own needs. At the same time, the central processor is set to store a motor rotor state software observer and a low-pass software filter. The user can choose whether to use the software algorithm to replace the motor rotor state observer and the low-pass filter through the central processor according to their own needs.

[0038] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0040] Figure 1 Shown is a schematic diagram of a motor rotor state observation method described in an embodiment of the present application.

[0041] Figure 2 Shown is a schematic diagram of the structure of the motor rotor state observer described in an embodiment of the present application.

[0042] Figure 3 Shown is a structural schematic diagram of the motor rotor angle estimation system described in an embodiment of the present application. DETAILED DESCRIPTION

[0043] The following describes the embodiments of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. The present application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0044] It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application, and thus the drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed at will, and the component layout may also be more complicated.

[0045] The following embodiments of the present application provide a motor rotor state observation method and observer, a motor rotor angle estimation system, including but not limited to a sliding film observer, a linear flux observer, and a nonlinear flux observer used in the field of motor control.

[0046] like Figure 1 As shown, this embodiment provides a method for observing the state of a motor rotor, which specifically includes the following steps.

[0047] Step S101, obtaining an original mathematical model of a state observer to be detected, and performing discrete transformation on the original mathematical model to obtain a conversion mathematical model of a preset form.

[0048] Specifically, the observer to be used for observing the motor rotor state is used as the state observer to be detected, and the original mathematical model of the state observer to be detected is obtained. Then, based on the mathematical model of the motor rotor state observer, the original mathematical model is discretized and mutated to obtain a conversion mathematical model in a preset form.

[0049] in,

[0050] Among them, X n To update the rotor state term, P s is the state parameter, X n-1 is the current rotor state item, P v is the voltage parameter, V is the latest real-time sampling voltage, Ex n-1 is the current expansion item, M is the limit parameter, K is the constant gain, P i is the current parameter, I is the latest real-time sampling current, Ex n is to update the extension item, and M is the limiting parameter.

[0051] Step S202, obtaining an initial rotor state item, an initial expansion item and a conventional parameter group based on a conversion mathematical model.

[0052] Specifically, actual physical meanings are given to parameters such as initial rotor state items, initial expansion items and conventional parameter groups based on the acquired conversion mathematical model, thereby obtaining a motor rotor state observer with determined parameters. The conventional parameter group includes state parameters, voltage parameters, current parameters, gain constants and limit parameters.

[0053] Step S203, obtaining the real-time sampled voltage and the real-time sampled current of the state observer to be detected, and obtaining the corresponding rotor state item and the extended item based on the real-time sampled voltage and the real-time sampled current obtained in real time.

[0054] Specifically, the current and voltage of the state observer to be detected are collected in real time to obtain the real-time sampled voltage and the real-time sampled current. After the latest real-time sampled voltage and the real-time sampled current of the state observer to be detected are collected each time, the corresponding rotor state item and the extended item can be obtained based on the collected real-time sampled voltage and the real-time sampled current in the following manner.

[0055] The process of further acquiring the corresponding rotor state item based on the real-time sampled voltage collected once includes: acquiring the state parameter item through multiplication based on the current rotor state item and state parameter of the state observer to be detected; then acquiring the voltage parameter item through multiplication based on the latest acquired real-time sampled voltage and voltage parameter; then acquiring the updated rotor state item by summing and integrating the current extension item, the state parameter item and the voltage parameter item; finally, updating the current rotor state item of the state observer to be detected based on the acquired updated rotor state item.

[0056] The process of further acquiring the corresponding extension item based on the real-time sampled current collected once includes: acquiring the current parameter item through multiplication based on the latest acquired real-time sampled current and current parameter; then integrating by summing the current parameter item and the updated rotor state item to obtain the initial extension item; then multiplying the initial extension item with the initial extension item to achieve gain of the initial extension item, and multiplying the limiting parameter with the initial extension item after gain to achieve limiting of the initial extension item after gain, thereby obtaining the updated extension item; finally, updating the current extension item of the state observer to be detected based on the acquired updated extension item.

[0057] To illustrate the motor rotor state observation method according to an embodiment of the present invention in more detail, the following takes a sliding film observer, a linear flux observer and a nonlinear flux observer as examples to obtain corresponding updated rotor state items and updated extension items.

[0058] 1) Take the synovial membrane observer as an example for explanation.

[0059] The sliding film observer reconstructs the back electromotive force of the motor through the voltage and current of the α-β coordinate system of the motor stator, and the back electromotive force of the motor contains the information of the electrical angle and electrical angular velocity of the motor rotor. Assuming that the Z-type function is used to estimate the back electromotive force, it simplifies the mathematical model of the sliding film observer and reduces the jitter phenomenon caused by the traditional sliding film observer. The original mathematical model of the sliding film observer is taken as:

[0060]

[0061] The above original mathematical model is discretized and mutated to obtain the synovial membrane mathematical model:

[0062]

[0063] At this time, the motor rotor current can be estimated Defined as updating the rotor state term X n , the motor back EMF term Z αβ (n) Defined as Update Extension Ex n , state parameter Voltage parameters The current parameter is P i =1, constant gain Limiting parameter M = lmt, sampling current I αβ =i αβ , sampling voltage V aβ =v αβ . Shield the CPU from updating the extension Ex nThe write operation is performed, and the first adder / subtractor is configured as an adder, and the second and third adders / subtractors are configured as subtractors. When the motor rotor state observer is triggered to start a calculation (for example, the nth time, where n ≥ 1), the expansion item stores the n-1th iteration result obtained by the last sliding membrane mathematical model, that is:

[0064] Ex n-1 =Z αβ (n-1)

[0065] At this time, the rotor state term is calculated according to formula (4), that is:

[0066]

[0067] According to formula (4), the new back electromotive force is obtained as the extended term for the next iteration, and the iterative value is also used in the estimation of the motor rotor angle in the later stage. That is:

[0068] Ex n =Z αβ (n)

[0069] The hardware integration of the above observer only needs to provide sampling voltage, sampling current and gain parameters, limiting parameters, etc., and can obtain the observed current and back-electromotive force values ​​reflecting the rotor electrical angle without intervention under the trigger condition, and each iteration only needs to provide real-time sampling current and sampling voltage, and can automatically complete multiple iterations of the observed value and back-electromotive force under the trigger condition, providing a basis for the later estimation of the motor electrical angle. In addition, the hardware integration of the above observer also releases software processing resources to a great extent. In the system solution with a system frequency of 50Mhz, using this structure to obtain an observed current and back-electromotive force on the α and β axes requires about 10 machine clocks, accumulating about 200ns, greatly improving the operating efficiency of the entire system in FOC calculation.

[0070] 2) Take the linear flux observer as an example to illustrate.

[0071] The linear flux observer uses a mathematical model in a two-phase stationary coordinate system (α-β coordinate system) to establish a flux model using the stator voltage, current or motor speed signal that is easier to detect, and obtains the magnitude of the flux and the motor phase angle. Take one of the original mathematical models of the linear flux observer as:

[0072]

[0073] According to the discretization and variation of the above formula, the magnetic flux mathematical model is obtained:

[0074]

[0075] At this time, the motor rotor current is estimated Defined as updating the rotor state term X n , will update the extension Ex n Defined as the relevant term of the motor current, the configuration state parameter P s =1, voltage parameter P v =T s , current parameter P i =L s , constant gain K = k, limit parameter M = infinity, sampling current I αβ =i αβ , sampling voltage V aβ =v αβ . Allows the CPU to update extensions Ex n The write operation is performed, and the first adder / subtractor is configured as an adder, and the second adder / subtractor and the third adder / subtractor are configured as subtractors.

[0076] Before performing a calculation (for example, the nth time, where n ≥ 1), use the software to manually calculate R s T s i αβ Fill in the extension item to overwrite the extension item calculation obtained last time using this structure, that is:

[0077] Ex n-1 =R s T s i αβ

[0078] According to the trigger start in formula (6), the rotor state term (physical meaning is magnetic flux) is obtained, that is:

[0079]

[0080] According to formula (6), the sine and cosine of the new motor phase angle are obtained as the basis for the estimation of the motor rotor angle in the later stage, that is:

[0081] Ex n =cosθor sinθ

[0082] The extended mode of the above observer only needs to provide voltage parameters, current parameters and gain parameters, limit parameters, real-time sampling current and real-time sampling voltage of the motor, etc., and pre-fill the extended items Ex for flux calculation n-1, and then under the action of the trigger condition, the flux observation value reflecting the motor state and the observation value reflecting the motor angle are obtained. And in each iteration, when the current and voltage sampling values ​​are known, the central processor only needs to intervene once, and the single calculation of the observation value can be completed automatically under the action of the trigger condition, providing a basis for the later estimation of the motor electrical angle. To some extent, it also releases the central processor resources and improves the operating efficiency of the entire system in FOC calculation.

[0083] 3) Take the nonlinear flux observer as an example to illustrate.

[0084] In practical applications of motors, there is often a difference between the estimated flux amplitude in Example 2) and the actual flux amplitude due to DC bias or integral drift. Based on the linear observer, the nonlinear flux observer uses the difference between the estimated flux amplitude and the actual flux amplitude as the compensation term of the estimated flux component. The mathematical model of the nonlinear flux observer is:

[0085]

[0086] Where Ls is the stator inductance, ψ f It is a permanent magnetic flux and can be measured.

[0087] According to the discretization and variation of the above formula, the nonlinear magnetic flux mathematical model is obtained:

[0088]

[0089] At this time, the motor rotor current is estimated Defined as updating the rotor state term X n , will update the extension Ex n Defined as the relevant term of the motor current, the configuration state parameter P s =1, voltage parameter P v =T s , current parameter P i =L s , constant gain K = k, limit parameter M = infinity, sampling current I αβ =i αβ , sampling voltage V aβ =v αβ . Allows the CPU to update extensions Ex n The write operation is performed, and the first adder / subtractor is configured as an adder, and the second adder / subtractor and the third adder / subtractor are configured as subtractors.

[0090] Before executing a calculation (for example, the nth time, where n ≥ 1), use the software to manually calculate the sum of the motor current related terms and the flux compensation terms and fill them into the extended terms to cover the extended term calculation amount obtained by using the structure last time, that is:

[0091]

[0092] According to the trigger start in formula (8), the rotor state term (physical meaning is magnetic flux) is obtained, that is:

[0093]

[0094] According to formula (8), the sine and cosine of the new motor phase angle are obtained as the basis for estimating the motor rotor angle in the later stage, that is:

[0095] Ex n =cosθor sinθ

[0096] Compared with Example 2), Example 3) uses the extended mode, but Example 3) adds a magnetic flux compensation term, which is more suitable for more complex state observation requirements than Example 2). The extended mode can be applied to simple and deterministic linear systems as well as complex and uncertain nonlinear systems. The system's computational efficiency is not only improved, but also meets the customer's diverse expansion needs, leaving customers with a high degree of freedom.

[0097] The motor rotor state observation method provided by the embodiment of the present invention sets an extension item in the motor rotor state parameter, sets the motor rotor state determination form in combination with the extension item, and then obtains the motor rotor state information in all states in a recursive manner, thereby solving the problem that the existing motor rotor state observation method cannot meet the diverse and complex motor rotor conditions. The extension parameter can be applied to both simple and certain linear systems and complex and uncertain nonlinear systems, and the calculation efficiency of the system is not only improved, but also meets the customer's diverse expansion needs, leaving customers with a high degree of freedom.

[0098] like Figure 2 As shown, this embodiment provides a motor rotor state observer, including a connected data storage unit and a state observation process unit.

[0099] The data storage unit is mainly used to store the rotor state item information, extended item information, and conventional parameter group information of the rotor to be observed, and the current and voltage obtained by the three-phase current of the motor collected in real time from the outside through the coordinate system transformation are used as the sampling current and sampling voltage. The three-phase current of the motor is sampled by a voltage and current sampler, and a voltage and current sensor can be further selected as a voltage and current sampler, or other reasonable voltage and current sampling devices can be selected as voltage and current samplers. After the voltage and current sampler collects the real-time sampled voltage and real-time sampled current, it can be directly or through a central processing unit. Transfer it to the data storage unit for storage. Preferably, the conventional parameter group can be set to include state parameters, voltage parameters, current parameters, constant gain and limiting parameters. The state parameter is the parameter information of the rotor state item, the voltage parameter is the parameter information of the real-time sampled voltage, the current parameter is the parameter information of the real-time sampled current, and the limiting parameter is used to control the output range of the numbered virtual limiter.

[0100] Furthermore, the data storage unit can be set to any storage medium, for example, a register can be selected as a data storage unit. At the same time, the data storage unit in the embodiment of the present invention can also be composed of multiple memories. For example, it can be divided into four categories of memories according to function. The first category of memory is used to store parameter items related to the motor that reflect the uniqueness of the same type of motor, specifically including conventional parameter groups. The second category of memory is used to store observation accumulation items related to the current state of the rotor, specifically including rotor state items. The third category of memory is used to store accumulation items closely related to the diverse needs of customers, specifically including extension items. The fourth category of memory is used to store real-time sampling items related to the operation of the motor, specifically including real-time sampling current and real-time sampling voltage (in Figure 1 not reflected in the report).

[0101] The data storage unit is the implementation part of the software and hardware interaction interface in the motor rotor state observer, in which only the second type of memory and the third type of memory can be set to support write access and read access of the state observation process unit, the first type of memory and the fourth type of memory do not support write access to the state observation process unit, and the parameters in the conventional parameter group of the first type of memory and the real-time sampled current and real-time sampled voltage in the fourth type of memory can be given different physical meanings under different usage environments (for details, please refer to the specific examples in the motor rotor state observation method in the embodiment).

[0102] The state observation process unit includes a first arithmetic mechanism and a second arithmetic mechanism, which mainly realizes the operation of each parameter in the memory through the first arithmetic mechanism and the second arithmetic mechanism, thereby realizing the assignment of actual physical meanings to each parameter and the acquisition of required observation values. Further, the state observation process unit is used to obtain rotor state items, real-time sampled voltages, extension items and conventional parameter groups from the data storage unit, and based on the rotor state items, real-time sampled voltages, extension items and conventional parameter groups, obtain updated rotor state items through the first arithmetic mechanism; finally, the updated rotor state items are fed back to the digital storage unit to realize the update of the rotor state items in the data storage unit. At the same time, the state observation process unit is also used to obtain real-time sampled currents and conventional parameter groups from the data storage unit, and based on the updated rotor state items, real-time sampled currents and conventional parameter groups, obtain updated extension items through the second arithmetic mechanism, and finally, the updated extension items are fed back to the data storage unit to realize the update of the extension items in the data storage unit.

[0103] refer to Figure 1 As shown, the state observation process unit is a hardware circuit structure, which can be specifically configured to include a rotor state item process circuit and an extension item process circuit.

[0104] The rotor state item process circuit is used for obtaining the state parameter item through the operator based on the rotor state item and the state parameter in the conventional parameter group each time a group of real-time sampled voltage and real-time sampled current of the state observer to be detected in the data storage unit is read, and obtaining the voltage parameter item through the operator based on the read real-time sampled voltage and the voltage parameter in the conventional parameter group, integrating the extended item, the state parameter item and the voltage parameter item through the operator to obtain an updated rotor state item, and updating the rotor state item in the data storage unit based on the updated rotor state item.

[0105] Furthermore, the rotor state item flow circuit specifically includes a first logic multiplier, a second logic multiplier, a first logic adder / subtractor and a second logic adder / subtractor. The input end of the first logic multiplier is used to input the state parameter and the rotor state item, and the output of the first logic multiplier is connected to the input end of the first logic adder / subtractor. The input end of the second logic multiplier is used to input the voltage parameter and the real-time sampling voltage, and the output of the second logic multiplier is also connected to the input end of the first logic adder / subtractor. The output end of the first logic adder / subtractor is connected to the input end of the second logic adder / subtractor, and the input end of the second logic adder / subtractor also inputs the historical expansion item. The above connection structure can make the output end of the second logic adder / subtractor output the updated rotor state item. Further, the first logic multiplier and the second logic multiplier can be realized by time-sharing multiplexing the logic multiplier in the first arithmetic mechanism, and the first logic adder / subtractor and the second logic adder / subtractor can be realized by time-sharing multiplexing the logic adder / subtractor in the first arithmetic mechanism.

[0106] The extended item process circuit is used to obtain the current parameter item through the operator based on the read real-time sampled current and the current parameter in the conventional parameter group every time a group of real-time sampled voltages and real-time sampled currents of the state observer to be detected in the data storage unit is read, and the current parameter item and the updated rotor state item are integrated through the operator to obtain the initial extended item, the initial extended item is gained through the operator based on the gain constant in the conventional parameter group, and the initial extended item after gain is limited through the operator based on the limiting parameter in the conventional parameter group to obtain the updated extended item, and the extended item in the data storage unit is updated based on the updated extended item.

[0107] Furthermore, the extended item flow circuit includes a third logic multiplier, a third logic adder / subtractor, a fourth logic multiplier and a virtual limiter. The input end of the third logic multiplier inputs a current parameter and a real-time sampling current, and the output end of the third logic multiplier is connected to the input end of the third logic adder / subtractor. The input end of the third logic adder / subtractor also inputs an updated rotor state item (this step can be achieved by connecting the output end of the second logic adder / subtractor to the input end of the third logic adder / subtractor), and the output end of the third logic adder / subtractor is connected to the input end of the fourth logic multiplier. The input end of the fourth logic multiplier also inputs a constant gain, and the output end of the fourth logic multiplier is connected to the input end of the virtual limiter. The input end of the virtual limiter also inputs a limiting parameter. The above connection structure can make the output end of the virtual limiter output an updated extended item. Furthermore, the third logic multiplier can be implemented by the logic multiplier in the second arithmetic mechanism, the third logic adder / subtractor and the fourth logic multiplier can be implemented by time-sharing the logic adder / subtractor in the second arithmetic mechanism, and the virtual limiter is implemented by the limiter in the second arithmetic mechanism.

[0108] For the convenience of description, we assign special symbols to each parameter item. Specifically, the state parameter can be set as Ps and the voltage parameter can be set as P. v , the constant gain is set to K, and the rotor state term is set to X n-1 , update the rotor state item and set it to X n , the extension is set to Ex n-1 , update the extension setting to Ex n , the current parameter is set to P i , the real-time sampling current is set to I, the real-time sampling voltage is set to V, and the limiting parameter is set to M.

[0109] At this time, the updated rotor state term can be expressed by the formula:

[0110] X n =P s X n-1 +P v V+Ex n-1 ,Exn-1 ∈[-M,M]

[0111] The update extension can be expressed as:

[0112] Ex n =K(X n +P i I), Ex n ∈[-M,M]

[0113] It should be noted that the first arithmetic mechanism and the second arithmetic mechanism can also be set as a total arithmetic mechanism, and the total arithmetic mechanism can be set to include three independent computing devices, specifically including a logic adder / subtractor, a logic limiter, and a logic multiplier. The logic adder / subtractor can be configured as a logic adder or a logic subtractor through the control of the central processing unit. The limiter can also set the limiting parameters through the central processing unit to control the output range of the limiter. Assuming that lmt is the limiting parameter configured by the central processing unit (lmt>0), and wOUT is the output of the limiter, then wOUT must satisfy wOUT∈[-lmt,lmt].

[0114] At this time, when the state observation process unit is working, it is necessary to use time-sharing multiplexing to reuse the logical adder / subtractor, limiter and logical multiplier in the total arithmetic mechanism to realize the function of the state observation process unit. And it should be noted that in the time-sharing multiplexing process, the logical adder / subtractor, limiter and logical multiplier are all independent calculation individuals, and each calculation process and result will not affect the next calculation. Therefore, the total arithmetic mechanism in this embodiment is actually a time-sharing multiplexing total arithmetic mechanism. At this time Figure 1 The dotted circles representing computing devices are logical existences rather than actual physical existences.

[0115] Furthermore, the total arithmetic mechanism can also be configured to actually include a first logic multiplier, a second logic multiplier, a first logic adder / subtractor, a second logic adder / subtractor, a third logic multiplier, a third logic adder / subtractor, a fourth logic multiplier, and a virtual limiter. The connection method of each arithmetic device is as shown above. Figure 1 The dotted circle in the figure represents a real computing device, that is, an actual physical existence.

[0116] The motor rotor state observer of the embodiment of the present invention will iteratively update the rotor state item and the extended item every time the real-time sampled voltage and the real-time sampled current are updated. The motor rotor state observer structure can complete the observer estimation operation of multiple methods in hardware integration or extended mode.

[0117] The embodiment of the present invention discloses a motor rotor state observer for position sensorless motor control, which is a multifunctional and expandable integrated circuit structure that supports software and hardware collaboration. The motor rotor state observer of the embodiment of the present invention is hardware-based, and the addition of extension items shortens the estimation time of the entire motor rotor state observer, improves efficiency, and also takes into account the diverse scalability requirements of customers.

[0118] The motor rotor state observer in the embodiment of the present invention not only absorbs the advantages of fast hardware speed and stable processing, but also absorbs the advantages of high software flexibility and high scalability by means of reasonable division of software and hardware implementation parts, addition of extension items, time-sharing multiplexing, etc., and is a universal observer structure that combines the advantages of both parties that has not yet appeared on the market.

[0119] At present, there are various observer algorithms in the field of electronic control, such as synovial observer estimation, flux observer estimation and its extended estimation, which are completely different algorithms in software implementation. They are implemented using the same set of hardware observer structure. By giving different physical meanings to the parameters of the observer structure and configuring different physical parameters, the need to use the same multifunctional general observer to complete multiple different algorithms is achieved, which greatly reduces the hardware overhead.

[0120] In future scenarios, in order to pursue higher performance, wider application scenarios and faster motor speed, there will definitely be more complex and effective algorithms than sliding film and flux linkage to meet various customer needs. Therefore, extension items are specially introduced in this observer structure to pre-calculate the uncertain and nonlinear system factors in complex situations in the future and write them into extension items, and then use the extension method to estimate the observer. This method not only retains the flexibility, scalability and diversity of the software, but also absorbs the advantages of fast speed and stability of the hardware system.

[0121] like Figure 3 As shown, this embodiment also provides a motor rotor angle estimation system, including a central processing unit, a motor rotor state observer, a low-pass filter and an angle estimation module connected in sequence, and the central processing unit is also connected to the angle estimation module so that the estimated angle obtained by the angle estimation module is fed back to the central processing unit. The motor rotor state observer is the motor rotor state observer provided in the above embodiment.

[0122] Specifically, the central processor may be configured with only a data storage unit, or may be configured with a software observer, or may be configured with a software observer and a software filter. Further, the angle estimation module is an angle estimation module based on PLL angle estimation or an angle estimation module based on inverse tangent.

[0123] The low-pass filter may be a first-order filter; the PLL-based angle estimation module may include PLL calculation, PI calculation, angle estimation, etc.; the inverse tangent-based angle estimation module includes an inverse tangent hardware circuit. The above three modules are all existing devices, and their specific structures are not described in detail here.

[0124] The user can choose whether to use the software algorithm to replace the motor rotor state observer and the low-pass filter through the central processor according to their own needs, and use the angle estimation module based on the PLL angle estimation or the angle estimation module based on the arc tangent to achieve the estimation of the final angle. Therefore, the circuit structure of the motor rotor angle estimation system of the embodiment of the present invention can have the following six different angle estimation methods coordinated by software and hardware.

[0125] Method 1: CPU (only storage unit configured) + motor rotor state observer + low-pass filter + PLL-based angle estimation hardware acceleration module;

[0126] Method 2: CPU (only storage unit) + motor rotor state observer + low-pass filter + hardware acceleration module based on inverse tangent circuit;

[0127] Method 3: CPU (software observer) + low-pass filter + PLL-based angle estimation hardware acceleration module;

[0128] Method 4: CPU (software observer) + low-pass filter + hardware acceleration module based on inverse tangent circuit;

[0129] Mode 5: CPU (software observer + software filter) + PLL-based angle estimation hardware acceleration module;

[0130] Method six: CPU (software observer + software filter) + hardware acceleration module based on inverse tangent circuit.

[0131] The angle estimator structure of software and hardware working together supports hardware integration and software algorithm scalability, which not only releases part of the central processor resources and improves the speed of motor rotor position estimation, but also satisfies the diversity and scalability of customers' algorithms. For some customers who are proficient in motor control algorithms, methods three, four, five, and six are provided to retain the freedom of software algorithm development. For some customers who are not familiar with and proficient in motor control algorithms, methods one and two provide a good software and hardware collaborative interface. Ordinary users can complete the control of the motor field without in-depth understanding of complex algorithms, and can carry out secondary software development based on the present invention, solving the problem of high professionalism of software developers and high maintenance costs.

[0132] The motor rotor angle estimation system provided by the embodiment of the present invention realizes hardware acceleration of the most complex angle estimation algorithm in the field of electronic control, so that the chips of medium and low-end system frequencies can complete complex electronic control at a lower frequency, reduce the dependence of the motor control chip on the system frequency, and reduce the difficulty of algorithm development in the field of electronic control, solve the problems of high difficulty in software development and high maintenance cost, and expand the user group. The motor rotor angle estimation system provided supports hardware integration, supports software algorithm scalability, releases part of the CPU resources, improves the speed of motor rotor position estimation, and improves the overall performance of the chip. And the user can also choose to use the angle estimation module based on PLL or the angle estimation module based on inverse tangent through the central processing unit according to their own needs, and at the same time, the central processing unit is set to store the motor rotor state software observer and the low-pass software filter. The user can choose whether to use the software algorithm to replace the motor rotor state observer and the low-pass filter through the central processing unit according to their own needs. The description of the process or structure corresponding to each of the above figures has different focuses. For the part that is not described in detail in a certain process or structure, refer to the relevant description of other processes or structures.

[0133] The above embodiments are merely illustrative of the principles and effects of the present application and are not intended to limit the present application. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed in the present application shall still be covered by the claims of the present application.

Claims

1. A method for observing a motor rotor state, comprising: Whenever the latest real-time sampled voltage and real-time sampled current of the state observer to be detected are obtained: The state parameter items are obtained based on the current rotor state item and the state parameter calculation, and the voltage parameter items are obtained based on the latest real-time sampled voltage and voltage parameter calculation, the current extension item, the state parameter item and the voltage parameter item are integrated to obtain an updated rotor state item, and the current rotor state item is updated based on the updated rotor state item; And based on the latest real-time sampled current and current parameter calculation, the current parameter item is obtained, the current parameter item and the updated rotor state item are integrated to obtain an initial extension item, the initial extension item is gained based on a gain constant, and the initial extension item after gain is limited based on a limiting parameter to obtain an updated extension item, and the current extension item is updated based on the updated extension item.

2. The observation method according to claim 1 is characterized in that the current rotor state item and state parameter are obtained by multiplication to obtain the state parameter item; the latest real-time sampled voltage and voltage parameter are obtained by multiplication to obtain the voltage parameter item; the latest real-time sampled current and current parameter are obtained by multiplication to obtain the current parameter item.

3. The observation method according to claim 1, characterized in that, before the step of obtaining the latest real-time sampled voltage and real-time sampled current of the state observer to be detected, it also includes: Acquire an original mathematical model of the state observer to be detected, and perform discrete variation on the original mathematical model to obtain a conversion mathematical model of a preset form; Based on the conversion mathematical model, an initial rotor state item, an initial expansion item and a conventional parameter group are obtained, wherein the conventional parameter group includes a state parameter, a voltage parameter, a current parameter, a gain constant and a limiting parameter.

4. The observation method according to claim 3, characterized in that the conversion mathematical model expression in the preset form is: in, X n To update the rotor state term, P s is the state parameter, X n-1 is the current rotor state item, P v is the voltage parameter, V is the latest real-time sampling voltage, Ex n-1 is the current expansion item, M is the limit parameter, K is the constant gain, P i is the current parameter, I is the latest real-time sampling current, Ex n is to update the extension item, and M is the limiting parameter.

5. A motor rotor state observer, characterized in that: including a connected data storage unit and a state observation process unit; The data storage unit is used to store the real-time sampled voltage and real-time sampled current of the state observer to be detected, and is used to store the rotor state item, the extended item and the conventional parameter group; The state observation process unit includes a rotor state item process circuit and an extension item process circuit; The rotor state item flow circuit is used to execute the rotor state item update process in the motor rotor state observation method according to any one of claims 1 to 4 each time a group of real-time sampled voltages and real-time sampled currents of the state observer to be detected in the data storage unit are read; The extended item flow circuit is used to execute the extended item update process in the motor rotor state observation method described in any one of claims 1 to 4 each time a group of real-time sampled voltages and real-time sampled currents of the state observer to be detected in the data storage unit are read.

6. The observer according to claim 5, characterized in that The rotor state item flow circuit includes a first logic multiplier, a second logic multiplier, a first logic adder / subtractor, and a second logic adder / subtractor; The state parameter and the rotor state item are both input into the first logic multiplier, the voltage parameter and the real-time sampling voltage are input into the second logic multiplier, the output end of the first logic multiplier and the output end of the second logic multiplier are both connected to the input end of the first logic adder / subtractor, the extension item is input into the second logic adder / subtractor, the output end of the first logic adder / subtractor is also connected to the input end of the second logic adder / subtractor, and the output end of the second logic adder / subtractor outputs the updated rotor state item.

7. The observer according to claim 6, characterized in that The state observation process unit also includes a first arithmetic mechanism, the first logic multiplier and the second logic multiplier are realized by time-sharing multiplexing the logic multipliers in the first arithmetic mechanism, and the first logic adder / subtractor and the second logic adder / subtractor are realized by time-sharing multiplexing the logic adder / subtractors in the first arithmetic mechanism.

8. The observer according to claim 5, characterized in that The extended item flow circuit includes a third logic multiplier, a third logic adder / subtractor, a fourth logic multiplier and a virtual limiter; The current parameter and the real-time sampled current are both input into the third logic multiplier, the updated rotor state item is input into the third logic adder / subtractor, the output of the third logic multiplier is also connected to the input of the third logic adder / subtractor, the constant gain is input into the fourth logic multiplier, the output of the third logic adder / subtractor is connected to the input of the fourth logic multiplier, the limiting parameter is input into the virtual limiter, the output of the fourth logic multiplier is connected to the input of the virtual limiter, and the output of the virtual limiter outputs the updated expansion item.

9. The observer according to claim 8, characterized in that The state observation process unit also includes a second arithmetic mechanism, the third logic multiplier is implemented by the logic multiplier in the second arithmetic mechanism, the third logic adder / subtractor and the fourth logic multiplier are implemented by time-sharing the logic adder / subtractor in the second arithmetic mechanism, and the virtual limiter is implemented by the limiter in the second arithmetic mechanism.

10. A motor rotor angle estimation system, characterized in that: It includes a central processing unit, a motor rotor state observer, a low-pass filter and an angle estimation module connected in sequence, wherein the central processing unit is also connected to the angle estimation module so that the estimated angle obtained by the angle estimation module is fed back to the central processing unit; Wherein, the motor rotor state observer is the motor rotor state observer described in any one of claims 5-9.

11. The angle estimation system according to claim 10, characterized in that: The central processing unit stores a motor rotor state software observer, and the central processing unit is also connected to the low-pass filter.

12. The angle estimation system according to claim 10, characterized in that: The central processing unit stores a motor rotor state software observer and a low-pass software filter, and the central processing unit is also connected to the angle estimation module.

13. The angle estimation system according to any one of claims 10 to 12, characterized in that: The angle estimation module is an angle estimation module based on PLL angle estimation or an angle estimation module based on arc tangent.

Images