CN117674659B - Stator resistance sensitivity analysis method for sensorless control system based on voltage model - Google Patents

Abstract

The invention discloses a method and a system for analyzing the resistance sensitivity of a stator based on a voltage model sensorless control system, which relate to the technical field of induction motor cores and comprise the steps of calculating a steady-state value of an angle error between a rotor flux linkage vector and an observed rotor flux linkage vector; according to the flux linkage observation angle, introducing an angle error, calculating the angle error and the flux linkage amplitude ratio, and carrying out stator resistance sensitivity analysis; according to the motor control performance, introducing an angle error, calculating a performance variable, and carrying out stator resistance sensitivity analysis. The stator resistance sensitivity analysis method based on the voltage model sensorless control system comprehensively considers flux linkage observation and control performance, meets the requirement of analyzing and evaluating the performance of the voltage model sensorless control system based on the induction motor under the low-speed working condition, is beneficial to improving a control algorithm, improves the efficiency, further improves the stability of the system, and achieves better effects in the aspects of system efficiency and system stability.

Description

Stator resistance sensitivity analysis method for sensorless control system based on voltage model

Technical Field

The present invention relates to the core technical field of induction motors, and in particular to a stator resistance sensitivity analysis method of a sensorless control system based on a voltage model.

Background Art

In the field of motor control, how to maintain the stability of the induction motor speed sensorless control system at low speed and reduce the steady-state error has always been a research hotspot. When the speed sensorless control system is running at low speed, the speed identification accuracy decreases and the load capacity is weakened. At this time, flux observation is particularly important. Accurate flux observation helps to improve system performance, so the system generally adopts a flux observer based on an ideal model that does not rely on speed identification. However, under low-speed conditions, flux observation is limited by the motor algorithm structure and is highly sensitive to changes in motor parameters and inverter nonlinearity, resulting in reduced motor control performance and system instability.

For the speed sensorless control system of induction motor based on voltage model, the main difficulty lies in how to accurately obtain the relevant parameter sensitivity analysis model. Due to the coupling between speed identification and flux observation, existing parameter sensitivity research tends to explore in depth from one aspect, and all are based on the performance variables when running in speed sensor mode for calculation and analysis. In practical applications, the most common method is to perform parameter sensitivity analysis from the perspective of flux. This analysis uses the ratio of the rotor flux vector and the observed rotor flux vector when the motor is running in speed sensor mode to represent the sensitivity of the system. When the amplitude ratio is closer to 1 and the phase difference is closer to 0, it means that the parameter change has less impact on the control system. In addition, some studies have analyzed parameter sensitivity from the perspective of speed identification, using the measured speed in speed sensor mode for analysis. It was not until 2015 that studies began to explore the parameter sensitivity of the speed sensorless control system of induction motor directly based on full-order observers. However, due to the large amount of calculation involved and the analysis only from the speed perspective, the system flux and control performance are not comprehensively considered, and its practicality is limited. At present, there is no comprehensive stator resistance sensitivity analysis method, which restricts the improvement of the speed sensorless control system of induction motor based on voltage model.

Summary of the invention

In view of the above-mentioned problems, the present invention is proposed.

Therefore, the technical problem solved by the present invention is that the existing stator resistance sensitivity analysis method has high limitations and low practicality, and there is an optimization problem of how to provide key information for the optimal design of a speed sensorless control system.

To solve the above technical problems, the present invention provides the following technical solutions: a stator resistance sensitivity analysis method for a sensorless control system based on a voltage model, comprising calculating a steady-state value of an angle error between a rotor flux vector and an observed rotor flux vector; introducing an angle error according to a flux observation angle, calculating the angle error and the flux amplitude ratio, and performing a stator resistance sensitivity analysis; introducing an angle error according to motor control performance, calculating performance variables, and performing a stator resistance sensitivity analysis.

As a preferred solution of the stator resistance sensitivity analysis method of the voltage model sensorless control system described in the present invention, wherein: the steady-state value of the angle error includes establishing an expression, establishing an expression including observing the rotor flux The expression of the unknown quantity θ is expressed as:

Among them, α and β are voltage model coefficients. When α＝0, β＝0, the voltage model is SCVM. When α＝h _d , β＝h _q , the voltage model is CMCVM. is the rotor time constant, _ωe is the synchronous angular frequency, is the slip angular frequency, θ is the angular error between the rotor flux vector and the observed rotor flux vector, is the observed rotor flux, is the stator resistance error, _LM is the motor excitation inductance, i _d is the d-axis component of the stator current, and _RR is the rotor resistance.

As a preferred solution of the stator resistance sensitivity analysis method of the voltage model sensorless control system described in the present invention, wherein: the steady-state value of the angle error also includes a trigonometric function equation, including and The expressions of coefficients A, B, and C are expressed as:

A sin(2θ)+B cos(2θ)＝C

The steady-state value of the angle error θ is calculated only under the condition of A ² +B ² ≥C ^2. When A ² +B ² ＜C ² , θ has no steady-state solution. The operating region where θ has no steady-state solution is defined as an unstable region.

As a preferred solution of the stator resistance sensitivity analysis method of the voltage model sensorless control system described in the present invention, wherein: the flux amplitude ratio includes a flux vector amplitude expression, substituting θ into the original flux expression, the flux vector The amplitude expression of is expressed as:

The amplitude expression of the rotor flux vector ψ _R is expressed as:

The ratio of the actual rotor flux vector to the observed rotor flux vector is the sensitivity of the motor to the stator resistance.

As a preferred solution of the stator resistance sensitivity analysis method of the voltage model sensorless control system described in the present invention, the flux amplitude ratio also includes a flux amplitude ratio calculation formula, and the angle error between the rotor flux vectors is defined as θ. The flux amplitude ratio calculation formula is expressed as:

The angle error θ and flux amplitude ratio under different working conditions are calculated in the steady-state value region, and the stator resistance sensitivity is analyzed from the perspective of the system's flux observation.

As a preferred solution of the stator resistance sensitivity analysis method of the voltage model sensorless control system described in the present invention, the calculated performance variables include calculating the motor speed and the slip angular frequency, and the motor speed ω _r and the slip angular frequency ω _s are expressed as:

Where, the superscript ^ is the estimated value of the variable, _it is the T-axis component of the stator current, To identify the motor speed, under steady-state conditions The speed error is used to describe the system speed identification capability and speed control accuracy, which can be expressed as:

Among them, e _ω is the speed error. ω _r and e _ω are calculated under different working conditions in the steady-state value region, and the stator resistance sensitivity is analyzed from the perspective of system speed identification capability and control accuracy.

As a preferred solution of the stator resistance sensitivity analysis method of the voltage model sensorless control system described in the present invention, wherein: the stator resistance sensitivity analysis is included in the vector control, the d-axis current i _d is a preset value, and the expression of i _q is expressed as:

i _q and It forms a nonlinear relationship, and is obtained according to the motor torque formula and The relationship between them is expressed as:

Where _Te is the motor torque, p is the number of motor pole pairs, ψ is the rotor flux, i is the stator current, subscripts d and q are the d-axis and q-axis components of the variable in the synchronous coordinate system, respectively. _Te is strongly correlated with θ. The values of _iq and _Te under different working conditions are calculated in the steady-state value region, and the stator resistance sensitivity is analyzed from the system load capacity.

Another object of the present invention is to provide a stator resistance sensitivity analysis system for a sensorless induction motor system, which can calculate the angle error and the flux amplitude ratio through a flux observation angle module, analyze the sensitivity of the stator resistance, and solve the problem that the current motor stator resistance sensitivity analysis method is incomplete and has limited practicality.

As a preferred solution of the stator resistance sensitivity analysis system of the sensorless induction motor system described in the present invention, it includes: a steady-state value calculation module, a flux observation angle module, and a motor control performance module; the steady-state value calculation module is used to calculate the steady-state value of the angle error between the rotor flux vector and the observed rotor flux vector; the flux observation angle module is used to calculate the angle error and the flux amplitude ratio, and analyze the sensitivity of the stator resistance; the motor control performance module is used to construct an expression based on the angle error, calculate the performance variables under different working conditions, and perform stator resistance sensitivity analysis.

A computer device includes a memory and a processor, wherein the memory stores a computer program, and is characterized in that the processor executes the computer program to implement a step of a stator resistance sensitivity analysis method for a sensorless control system based on a voltage model.

A computer-readable storage medium stores a computer program thereon, wherein when the computer program is executed by a processor, the steps of a method for analyzing the stator resistance sensitivity of a sensorless control system based on a voltage model are implemented.

Beneficial effects of the present invention: The stator resistance sensitivity analysis method of the voltage model-based sensorless control system provided by the present invention comprehensively considers the flux observation and control performance, performs a comprehensive stator resistance sensitivity analysis on the system, and establishes a complete analysis model with moderate calculation cost. It meets the needs of analyzing and evaluating the performance of the induction motor sensorless control system based on the voltage model under low-speed conditions, and provides an important performance evaluation tool for optimizing the design of speed sensorless control systems, which is helpful to improve the control algorithm, improve efficiency, and thus enhance the stability of the system. The method of the present invention provides an intuitive perspective for designers, enabling them to clearly understand the performance of the sensorless control system based on the voltage model during the entire operation of the motor. The present invention achieves better results in terms of system efficiency and system stability.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

FIG. 1 is an overall flow chart of a method for analyzing stator resistance sensitivity of a sensorless control system based on a voltage model according to a first embodiment of the present invention.

FIG2 is a diagram showing the sensitivity of the stator resistance of a system when the angle error of the stator resistance sensitivity analysis method of a sensorless control system based on a voltage model provided by the second embodiment of the present invention varies within the range of [-20, 20].

3 is a diagram of system stator resistance sensitivity when the rotor flux amplitude ratio varies in the range of [0.8, 1.2] according to the voltage model-based sensorless control system stator resistance sensitivity analysis method provided in the second embodiment of the present invention.

4 is a diagram of the system stator resistance sensitivity with ω _r as the contour line speed identification angle according to the voltage model-based sensorless control system stator resistance sensitivity analysis method provided in the second embodiment of the present invention.

FIG. 5 is a diagram of system stator resistance sensitivity with _eω as the contour line speed identification angle according to a voltage model-based sensorless control system stator resistance sensitivity analysis method provided in a second embodiment of the present invention.

6 is a diagram of the system stator resistance sensitivity with i _q as the contour line motor load capacity angle according to the voltage model sensorless control system stator resistance sensitivity analysis method provided in the second embodiment of the present invention.

7 is a diagram of the system stator resistance sensitivity with _Te as the contour line motor load capacity angle according to the voltage model sensorless control system stator resistance sensitivity analysis method provided in the second embodiment of the present invention.

FIG8 is an overall flow chart of a stator resistance sensitivity analysis system for a sensorless induction motor system provided by a third embodiment of the present invention.

DETAILED DESCRIPTION

In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

Example 1

1 , which is an embodiment of the present invention, provides a method for analyzing stator resistance sensitivity of a sensorless control system based on a voltage model, including:

S1: Calculate the steady-state value of the angular error between the rotor flux vector and the observed rotor flux vector.

Furthermore, the steady-state value of the angle error involves establishing an expression.

It should be noted that the establishment of the rotor flux The expression of the unknown quantity θ is expressed as:

Among them, α and β are voltage model coefficients. When α＝0, β＝0, the voltage model is SCVM. When α＝h _d , β＝h _q , the voltage model is CMCVM. is the rotor time constant, _ωe is the synchronous angular frequency, is the slip angular frequency, θ is the angular error between the rotor flux vector and the observed rotor flux vector, is the observed rotor flux, is the stator resistance error, _LM is the motor excitation inductance, i _d is the d-axis component of the stator current, and _RR is the rotor resistance.

Furthermore, the steady-state value of the angle error also includes trigonometric equations.

It should be noted that and The expressions of coefficients A, B, and C are expressed as:

A sin(2θ)+B cos(2θ)＝C

The steady-state value of the angle error θ is calculated only under the condition of A ² +B ² ≥C ^2. When A ² +B ² ＜C ² , θ has no steady-state solution. The operating region where θ has no steady-state solution is defined as an unstable region.

S2: According to the flux observation angle, the angle error is introduced, the angle error and flux amplitude ratio are calculated, and the stator resistance sensitivity analysis is performed.

Furthermore, the flux linkage magnitude ratio includes a flux linkage vector magnitude expression.

It should be noted that when θ is substituted into the original flux expression, the flux vector The amplitude expression of is expressed as:

The amplitude expression of the rotor flux vector ψ _R is expressed as:

The ratio of the actual rotor flux vector to the observed rotor flux vector is the sensitivity of the motor to the stator resistance.

Furthermore, the flux amplitude ratio also includes a flux amplitude ratio calculation formula.

It should be noted that the angle error between the rotor flux vectors is defined as θ, and the flux amplitude ratio calculation formula is expressed as:

The angle error θ and flux amplitude ratio under different working conditions are calculated in the steady-state value region, and the stator resistance sensitivity is analyzed from the perspective of the system's flux observation.

S3: According to the motor control performance, the angle error is introduced, the performance variables are calculated, and the stator resistance sensitivity analysis is performed.

Furthermore, calculating the performance variable includes calculating the motor speed and the slip angle frequency.

It should be noted that the motor speed ω _r and the slip angle frequency ω _s are expressed as:

Where, the superscript ^ is the estimated value of the variable, _it is the T-axis component of the stator current, To identify the motor speed, under steady-state conditions The speed error is used to describe the system speed identification capability and speed control accuracy, which can be expressed as:

Among them, e _ω is the speed error. ω _r and e _ω are calculated under different working conditions in the steady-state value region, and the stator resistance sensitivity is analyzed from the perspective of system speed identification capability and control accuracy.

Furthermore, the stator resistance sensitivity analysis includes analyzing the load carrying capacity of the system.

It should be noted that in vector control, the d-axis current i _d is a preset value, and the expression for i _q is expressed as:

i _q and It forms a nonlinear relationship, and is obtained according to the motor torque formula and The relationship between them is expressed as:

Where _Te is the motor torque, p is the number of motor pole pairs, ψ is the rotor flux, i is the stator current, subscripts d and q are the d-axis and q-axis components of the variable in the synchronous coordinate system, respectively. _Te is strongly correlated with θ. The values of _iq and _Te under different working conditions are calculated in the steady-state value region, and the stator resistance sensitivity is analyzed from the system load capacity.

Example 2

2 to 7 , an embodiment of the present invention provides a method for analyzing the stator resistance sensitivity of a sensorless control system based on a voltage model. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through economic benefit calculation and simulation experiments.

The method of the present invention is applied to the speed sensorless control system of the induction motor based on the static compensation voltage model (SCVM) and the voltage and current combination model (CMCVM), and the rotor flux expression in the synchronous coordinate system of the observed flux orientation is expressed as:

The superscript ^ represents the estimated value of the corresponding variable, and the subscripts d and q represent the d-axis and q-axis components of the corresponding variable in the synchronous coordinate system, respectively. is the observed synchronous angular frequency, ψ _R is the rotor flux vector, E is the rotor electromotive force vector, E＝E _d +jE _q ， is the rotor time constant, and the flux observer constructed by SCVM is expressed as:

Where _λs is the design parameter of SCVM. The current model in the synchronous coordinate system is simplified to L _M i _d , and the flux observer constructed by CMCVM is expressed as:

Among them, _Rs , _is , _LM and _Lσ are the motor stator resistance, stator current, excitation inductance and total leakage inductance respectively. H＝h _d +jh _q is the design parameter of CMCVM. Speed identification is achieved by subtracting the slip frequency from the synchronous frequency, which is expressed as:

in, To identify the motor speed, is the slip angular frequency, R _R is the rotor resistance, and the method of the present invention is applied to two speed sensorless control systems of induction motors based on voltage models. Since the sensitivity analysis is performed under steady-state conditions, the formula can be obtained after transformation, which is expressed as:

The component of the rotor flux in the d-q axis is expressed as:

_ψd = _ψR cos(θ)

ψ _q = ψ _R sin(θ)

Among them, θ is the angle between the rotor flux vector and the d-axis oriented with the observed flux vector. The direction of the rotor flux vector is set as the M-axis. The speed sensorless vector control is implemented on the dq axis. and are two control variables of the system. Usually, i _d is set as a constant within the basic speed range, and i _q is calculated as:

According to the projection relationship, the component of the motor stator resistance _is on the MT axis can be expressed as:

i _m =i _d cos(θ)+i _q sin(θ)

i _t =-i _d sin(θ)+i _q cos(θ)

Therefore, the expression of rotor flux is derived as:

When only the sensitivity of the stator resistance is considered, the component relationship of the back electromotive force E on the d-q axis is expressed as:

in, is the stator resistance error. In order to optimize the operating performance of the motor control system, the parameters _λs and H of the two voltage models are designed. When the motor parameters are correct, the parameters of the flux observation system are designed to ensure the stability of the flux observation. A strongly coupled third-order nonlinear state equation is established. In this equation, the state variable is When the parameters are not considered When , the steady-state value [ψ _ref 0 ψ _ref ] ^T can be obtained. The state equation is linearized, and the detailed parameters are shown in Table 2. The linearization process is expressed as:

The detailed parameters of the characteristic polynomial are shown in Table 3. The characteristic polynomial is expressed as:

F(s)＝s ³ +c ₂ s ² +c ₁ s+c ₀

Using Routh criterion for stability analysis, the parameter designs of the two voltage models are expressed as:

λ _s =λsign(ω _e )

in, k＞0, for SCVM, as ω _swt increases, γ approaches 0, The maximum value 2 is reached when the motor is running at rated load. ω _swt ＞10.5, for CMCVM, the larger the k value, the wider the stable operating range, but the noise The larger the value, the steady-state value of the angle error θ between the rotor flux vector and the observed flux vector is calculated. After substitution, the value including the observed rotor flux is obtained. The equation for the unknown quantity θ can be expressed as follows:

Among them, the above formula Eliminate i and _id , and we get the trigonometric equation about θ, where coefficients A, B, and C are and The expression of is:

A sin(2θ)+B cos(2θ)＝C

The steady-state value of θ can only be obtained under the condition of A ² +B ² ≥C ² , that is, θ has no solution under some operating conditions. When θ has no solution, the corresponding operating area of the system is defined as an unstable area. When performing stator resistance sensitivity analysis from the perspective of flux observation, substituting θ into the original flux expression can obtain the observed rotor flux. The expression is expressed as:

Will Substituting in, we can get the expression of rotor flux ψ _R as:

Introducing the angle error θ, the amplitude ratio of the rotor flux vector is calculated and expressed as:

In the steady-state value region, the θ and flux amplitude ratio under different working conditions are calculated. The stator resistance sensitivity of the system can be analyzed from the perspective of observing the flux. When the stator resistance sensitivity is analyzed from the perspective of motor control performance, the system speed recognition capability and speed control accuracy are analyzed to calculate ω _r and ω _s , which are expressed as:

_ωs is affected by the observed flux and angle error θ. Under steady-state conditions, and Equal, the speed error can be used to describe the system speed recognition ability and speed control accuracy, expressed as:

By calculating _ωr and _eω under different working conditions in the steady-state value region, the stator resistance sensitivity of the system can be analyzed from the perspective of speed recognition capability and control accuracy. When analyzing from the perspective of load carrying capacity with different current amplitudes, in the current control link, i _d is a constant preset by the system, and the expression for i _q is expressed as:

i _q follow It becomes a nonlinear relationship, and when it is substituted into the expression of motor torque _Te , we get and The relationship between them is expressed as:

By calculating the values of _iq and _Te under different working conditions in the steady-state value region, the stator resistance sensitivity of the system can be analyzed from the load capacity.

Table 1 shows the parameter information of the experimental motor. In the process of solving θ and other parameters, the and All are dynamic variables. Changing in the range of 0-300rpm, Changing from negative to positive rated values, Equivalent to ±20% R _s .

From the perspective of flux observation, the stator resistance sensitivity is analyzed. θ can only be solved under the condition of A ² +B ² ≥C ² , that is, θ has no steady-state solution under some operating conditions. When the steady-state value cannot be solved, the corresponding operating condition area is defined as an unstable area. The method of the present invention is used in the induction motor speed sensorless control system based on SCVM and CMCVM respectively. The unstable area is marked with red * in the plane, and the unstable area is mainly distributed in the low speed range with regenerative load. When , most of the unstable regions are distributed above ω _e = 0. When ω e = 0, most of the unstable regions are distributed below ω _e = 0.

Figure 2 shows the sensitivity of the system stator resistance when the angle error varies in the range of [-20,20] with θ as the contour line. The contour lines show the system stator resistance sensitivity when the rotor flux amplitude ratio changes in the range of [0.8, 1.2]. The unstable area of the speed sensorless control system based on CMCVM is relatively wide. It is very obvious under the conditions. From this perspective, the speed sensorless control system based on SCVM has weaker stator resistance sensitivity. When the rotor flux amplitude ratio is closer to 1 and the phase difference is closer to 0, it means that the parameter change has less impact on the control system. From this perspective, the system based on CMCVM converges faster.

From the perspective of control performance, the stator resistance sensitivity is analyzed. Figure 4 uses ω _r as the contour line, and Figure 5 uses e _ω as the contour line. From the perspective of speed identification, the stator resistance sensitivity of the system is shown. The contour lines in Figure 4 should be perpendicular to axis, but due to the influence of stator resistance, the ω _r contour lines of the two systems are bent. The bending phenomenon of the induction motor speed sensorless control system based on SCVM is more serious only in the extremely low speed area, while the bending phenomenon of the system based on CMCVM is obvious in the low-speed regenerative load and heavy load area.

As can be seen from Figure 5, the speed error of the system based on SCVM is relatively smaller, while the system based on CMCVM still has a large speed error in the extremely low-speed electric load area and the low-speed regenerative load and heavy load area.

Figure 6 uses i _q as contour lines, and Figure 7 uses _Te as contour lines, which show the stator resistance sensitivity of the system from the perspective of motor load capacity. The contour lines of Figures 6 and 7 should be parallel to axis, and with The change in the speed is translated up and down, but due to the influence of the stator resistance, serious bending occurred in the experiment. The contour lines of the SCVM-based system showed more serious deformation under all conditions, including in the extremely low speed area and the low-speed regenerative load and heavy load area. The CMCVM-based system showed better performance, and the load capacity was less affected by the stator resistance.

In terms of flux observation, the SCVM-based system has a larger stable area, while the CMCVM-based system has an advantage in the flux vector convergence speed. In terms of speed control accuracy, the SCVM-based system is more sensitive to stator resistance in the extremely low speed area and has poor performance, while the CMCVM-based system has a larger unstable area under low-speed regenerative load and heavy load conditions. In terms of load capacity under corresponding current amplitudes, the CMCVM-based system has better performance both in extremely low speed conditions and under conditions with regenerative loads, and is relatively less sensitive to stator resistance.

Table 1 Detailed parameters of the test motor

parameter Numeric parameter Numeric Rated Power 4kW Pole pairs 2 Rated voltage 380V Stator resistance 1.1578Ω Rated current 8.66A Rotor resistance 0.6629Ω Rated speed 1455rpm Excitation inductance 135.59mH Rated slip frequency 9.42rad/s Leakage Inductance 12.63mH

Table 2 Related parameters of state equation

Table 3. Table of relevant parameters of characteristic polynomial

Example 3

8 , which is an embodiment of the present invention, provides a stator resistance sensitivity analysis system for a sensorless induction motor system, including a steady-state value calculation module, a flux observation angle module, and a motor control performance module.

The steady-state value calculation module is used to calculate the steady-state value of the angle error between the rotor flux vector and the observed rotor flux vector; the flux observation angle module is used to calculate the angle error and the flux amplitude ratio, and analyze the sensitivity of the stator resistance; the motor control performance module is used to construct an expression based on the angle error, calculate the performance variables under different working conditions, and perform stator resistance sensitivity analysis.

If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

The logic and/or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc. It should be noted that the above embodiments are only used to illustrate the technical solution of the present invention and are not limited. Although the present invention is described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims (5)

1. The method for analyzing the stator resistance sensitivity of the sensorless control system based on the voltage model is characterized by comprising the following steps of:

Calculating a steady state value of an angle error between a rotor flux linkage vector and an observed rotor flux linkage vector;

According to the flux linkage observation angle, introducing an angle error, calculating the angle error and the flux linkage amplitude ratio, and carrying out stator resistance sensitivity analysis;

According to the motor control performance, introducing an angle error, calculating a performance variable, and carrying out stator resistance sensitivity analysis;

the steady state value of the angle error includes establishing an expression, including observing the rotor flux linkage And the expression of the unknown quantity θ is expressed as:

where α and β are voltage model coefficients, the voltage model is SCVM when α=0, β=0, the voltage model is CMCVM when α=h _d,β＝h_q, For the rotor time constant, omega _e is the synchronous angular frequency,For slip angular frequency, θ is the angular error between the rotor flux vector and the observed rotor flux vector,In order to observe the flux linkage of the rotor,L _M is motor excitation inductance, i _d is d stator current d-axis component, and R _R is rotor resistance;

the steady state value of the angle error also comprises a trigonometric function equation including AndThe expression of the coefficient A, B, C is expressed as:

Asin(2θ)+Bcos(2θ)＝C

Calculating a steady state value of the angle error theta only under the condition of A ²+B²≥C², wherein when A ²+B²＜C², the angle error theta has no steady state solution, and a working condition area of the angle error theta with no steady state solution is defined as an unstable area;

The flux linkage amplitude ratio comprises a flux linkage vector amplitude expression, and theta is substituted into the original flux linkage expression and the flux linkage vector The amplitude expression of (c) is expressed as:

The magnitude expression of the rotor flux linkage vector _R is expressed as:

ratio of actual rotor flux linkage vector to observed rotor flux linkage vector Stator for motor pair the sensitivity of the resistor;

The flux linkage amplitude ratio also comprises a flux linkage amplitude ratio calculation formula, wherein an angle error between rotor flux linkage vectors is defined as theta, and the flux linkage amplitude ratio calculation formula is expressed as:

Calculating angle errors theta and flux linkage amplitude ratios under different working conditions in a steady-state value region, and analyzing the sensitivity of the stator resistance from the flux linkage observation angle of the system;

The calculation performance variables include calculation of motor speed and slip angular frequency, and motor speed ω _r and slip angular frequency ω _s are expressed as:

wherein the superscript is the estimated value of the variable, i _t is the stator current T-axis component, To identify the rotation speed of the motor under steady-state working conditionDescribing the system speed recognition capability and speed control accuracy using the rotational speed error, expressed as:

Wherein e _ω is a rotation speed error, ω _r and e _ω under different working conditions are calculated in a steady state value region, and the sensitivity of the stator resistance is analyzed from the system speed identification capability and the control precision.

2. The voltage model sensorless control system stator resistance sensitivity analysis method of claim 1, wherein: the stator resistance sensitivity analysis is included in vector control, d-axis current i _d is a preset value, and the expression of i _q is expressed as follows:

i _q and Is in nonlinear relation and is obtained according to a motor torque formulaAnd e _Rs is expressed as:

wherein T _e is motor torque, p is motor pole pair number, ψ is rotor flux, i is stator current, subscripts d and q are d-axis and q-axis components of variables in a synchronous coordinate system respectively, T _e is strongly related to θ, values of i _q and T _e under different working conditions are calculated in a steady-state value area, and stator resistance sensitivity is analyzed from system load capacity.

3. A system employing the voltage model sensorless control system stator resistance sensitivity analysis method of any one of claims 1-2, characterized in that: the device comprises a steady state value calculation module, a flux linkage observation angle module and a motor control performance module;

The steady state value calculation module is used for calculating a steady state value of an angle error between a rotor flux linkage vector and an observed rotor flux linkage vector;

The flux linkage observation angle module is used for calculating angle errors and flux linkage amplitude ratios and analyzing sensitivity of the stator resistance;

the motor control performance module is used for constructing an expression based on the angle error, calculating performance variables under different working conditions and analyzing the sensitivity of the stator resistance.

4. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that the processor, when executing the computer program, implements the steps of the voltage model-based sensorless control system stator resistance sensitivity analysis method of any one of claims 1 to 2.

5. A computer readable storage medium having stored thereon a computer program, characterized in that the computer program when executed by a processor implements the steps of the voltage model based sensorless control system stator resistance sensitivity analysis method of any one of claims 1 to 2.