Sensorless control method and system for reluctance motor based on high frequency voltage correction

Abstract

The application provides a sensorless control method and system for a reluctance motor based on high-frequency voltage correction, which comprises the following steps: sampling three-phase currents output by a synchronous reluctance motor to obtain three-phase current data; transforming the three-phase currents to obtain alpha-beta axis currents; processing the alpha-beta axis currents and signals lagging behind the alpha-beta axis currents by half a period to obtain high-frequency alpha-beta axis currents; transforming the alpha-beta axis currents to obtain dq axis currents, processing the currents and signals lagging behind the currents by half a period to obtain base-frequency dq axis currents; subtracting the high-frequency alpha-beta axis currents from the lagging currents to obtain current variation; processing the obtained current variation through a phase-locked loop structure to obtain an estimated rotating speed and an estimated rotor position; and processing the estimated rotating speed and the estimated rotor position to obtain a switching signal, wherein the switching signal is used for controlling the synchronous reluctance motor.

Description

Technical Field

[0001] This invention belongs to the field of synchronous reluctance motor control technology, and particularly relates to a sensorless control method and system for reluctance motors based on high-frequency voltage correction. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] Synchronous reluctance motors (SRRMs) are considered an ideal replacement for induction motors in various industrial fields due to their simple manufacturing process, high operating efficiency, and low production and maintenance costs. Traditional SRRM control requires mechanical sensors, which are prone to failure under harsh conditions such as high temperatures, vibration, and dust. In large-scale production, the presence of sensors significantly increases the overall system cost, negatively impacting product competitiveness. Regular inspection and maintenance are also necessary, and sensor wear and aging may necessitate replacement, increasing maintenance costs and complexity. Therefore, the need for reliable, high-precision sensorless control of SRRMs is urgent.

[0004] Commonly used sensorless control methods can be divided into two categories: those suitable for zero-speed and low-speed applications, and those suitable for medium-speed and high-speed applications. Zero-speed methods include high-frequency square wave injection, high-frequency sine wave injection, and high-frequency pulse signal injection. When using high-frequency signal injection, additional torque fluctuations and noise are introduced. In sensorless control using a single-axis high-frequency square wave voltage signal injection, the injected high-frequency square wave voltage signal is typically used directly as the high-frequency voltage value to derive the αβ high-frequency current equation, which includes the rotor position error θ. err Information is used to derive the traditional phase-locked loop (PLL) structure through vector cross products. However, due to the coupling effect of the mathematical model of the synchronous magneto, if a high-frequency square wave voltage signal is injected into the d-axis, a corresponding high-frequency voltage signal will be generated in the q-axis; conversely, if a high-frequency square wave voltage signal is injected into the q-axis, a corresponding high-frequency voltage signal will be generated in the d-axis. Therefore, the injected high-frequency square wave voltage signal is not a true high-frequency voltage value, leading to inaccurate αβ high-frequency current equations and consequently, inaccurate derived PLL structures. This results in errors between the estimated rotor position and the actual rotor position, affecting the control accuracy of sensorless motor control, manifesting as torque and speed fluctuations. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, this invention provides a sensorless control method for reluctance motors based on high-frequency voltage correction, which reduces rotor position estimation error by improving the phase-locked loop structure.

[0006] To achieve the above objectives, one or more embodiments of the present invention provide the following technical solutions:

[0007] In the first aspect, a sensorless control method for a reluctance motor based on high-frequency voltage correction is disclosed, including:

[0008] The three-phase current output by the synchronous reluctance motor is sampled to obtain the three-phase current data;

[0009] The αβ axis current is obtained by transforming the three-phase current;

[0010] The high-frequency αβ-axis current is obtained by processing the αβ-axis current and its hysteresis half-cycle signal.

[0011] The αβ axis current is transformed to obtain the dq axis current, and the fundamental frequency dq axis current is obtained by processing the current and its half-cycle lag signal.

[0012] The change in current is obtained by subtracting the high-frequency αβ-axis current from the hysteresis current.

[0013] The obtained current change is processed through a phase-locked loop structure to obtain the estimated speed and estimated rotor position;

[0014] The estimated rotational speed and estimated rotor position are processed to obtain a switching signal, which is used to control the synchronous reluctance motor.

[0015] As a further technical solution, the estimated rotational speed and estimated rotor position are processed to obtain a switching signal, specifically as follows:

[0016] The difference between the estimated speed and the reference speed is calculated, and the current distribution of the dq axis is determined based on the maximum torque-current ratio. The dq axis voltage is obtained through the current loop, and the signal is processed to obtain a switching signal for processing a DC voltage source, which is used to control the synchronous reluctance motor.

[0017] As a further technical solution, the obtained current change is processed through a phase-locked loop structure to obtain the estimated speed and estimated rotor position. The specific process is as follows:

[0018] The change in current Δi along the αβ axis αh , Δi βh The data contains rotor position information. Δi is obtained by multiplying the change in αβ axis current by the sign function of the corresponding injected high-frequency voltage. αh Sign(u dh ), Δi βh Sign(u dh (or Δi) αh Sign(u qh ), Δi βh Sign(u qh This yields rotor position information θ. e Trigonometric functions.

[0019] Because the improved phase-locked loop structure takes into account the coupling effect of the synchronous reluctance motor, the product of the change in αβ-axis current and the sign function of the corresponding high-frequency voltage is a rotor position information θ. e and compensation angle The sum of trigonometric functions.

[0020] Therefore, Δi αh Sign(u dh ), Δi βh Sign(u dh (or Δi) αh Sign(u qh ), Δi βh Sign(u qh The rotor position error θ is obtained by constructing a trigonometric function from the sum of the estimated rotor position information and the compensation angle, and then performing a vector cross product. err The rotor position error is used to obtain the estimated speed through PI control, and the rotor position error is used to obtain the estimated rotor position.

[0021] Add a compensation angle to the estimated rotor position. Constructing trigonometric functions and Δi αh Sign(u dh ), Δi βh Sign(u dh (or Δi) αh Sign(u qh ), Δi βh Sign(u qh Perform a vector cross product to form a closed loop.

[0022] Secondly, a sensorless control system for a reluctance motor based on high-frequency voltage correction is disclosed, including:

[0023] The three-phase current data sampling module is configured to sample the three-phase current output by the synchronous reluctance motor to obtain three-phase current data.

[0024] The three-phase current data processing module is configured to transform the three-phase currents to obtain the αβ axis currents.

[0025] The high-frequency αβ-axis current is obtained by processing the αβ-axis current and its hysteresis half-cycle signal.

[0026] The αβ axis current is transformed to obtain the dq axis current, and the fundamental frequency dq axis current is obtained by processing the current and its half-cycle lag signal.

[0027] The change in current is obtained by subtracting the high-frequency αβ-axis current from the hysteresis current.

[0028] The speed and rotor position estimation module is configured to process the obtained current change through a phase-locked loop structure to obtain the estimated speed and estimated rotor position;

[0029] The control module is configured to process the estimated rotational speed and estimated rotor position to obtain a switching signal, which is used to control the synchronous reluctance motor.

[0030] The above one or more technical solutions have the following beneficial effects:

[0031] The present invention discloses a sensorless control method for a synchronous reluctance motor based on an improved phase-locked loop (PLL) structure, comprising: obtaining the current change value and rotor position relationship of the αβ axis system when a high-frequency square wave is injected alone into the d-axis or q-axis; determining the rotor position error by determining the PLL structure; obtaining the estimated speed by PI regulation; and obtaining the rotor position by integrating the estimated speed. Due to the coupling effect, the voltage value when a high-frequency square wave voltage signal is injected alone into the d-axis or q-axis is corrected to obtain the corrected current change value and rotor position relationship. The rotor position error is obtained by the improved PLL structure; the estimated speed is obtained by PI regulation; and the rotor position is obtained by integrating the estimated speed, thus achieving sensorless control.

[0032] The technical solution of this invention is a sensorless control method for synchronous reluctance motors based on an improved phase-locked loop structure. By correcting the high-frequency voltage value and improving the phase-locked loop structure, the rotor position estimation error is reduced.

[0033] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0034] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0035] Figure 1 This is a flowchart of the sensorless control of the synchronous reluctance motor with d-axis high-frequency square wave injection described in this invention;

[0036] Figure 2 This invention relates to an improved phase-locked loop structure for d-axis high-frequency injection;

[0037] Figure 3 It is the difference between the actual rotor position and the estimated rotor position when the d-axis high-frequency square wave is injected into the sensorless control. The operating conditions are set to a speed of 500 r / min and an amplitude of 2 Nm. The red solid line is the result obtained by the traditional phase-locked loop, and the blue solid line is the result obtained by the improved phase-locked loop.

[0038] Figure 4This is a flowchart of the sensorless control of the synchronous reluctance motor with q-axis high-frequency square wave injection described in this invention;

[0039] Figure 5 This invention relates to an improved phase-locked loop structure for q-axis high-frequency injection;

[0040] Figure 6 This is the difference between the actual rotor position and the estimated rotor position when a high-frequency square wave is injected into the q-axis for sensorless control. The operating conditions are set to a speed of 500 r / min and an amplitude of 2 Nm. The red solid line represents the result obtained by the traditional phase-locked loop, and the blue solid line represents the result obtained by the improved phase-locked loop. Detailed Implementation

[0041] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0042] It should be noted that the terminology used herein is for the purpose of describing particular implementations only and is not intended to limit the exemplary implementations of the present invention.

[0043] Where there is no conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0044] Overall concept:

[0045] A mathematical model of a synchronous reluctance motor in a rotating coordinate system is established.

[0046] In the estimation of the d-axis or q-axis of the rotating coordinate system, a high-frequency square wave signal is injected, the three-phase current of the synchronous reluctance motor is sampled, the response current in the rotating coordinate system is determined according to the Clarke transform, and the fundamental frequency quadrature-direct axis current and the quadrature-direct axis high-frequency response current are determined using the hysteresis half-cycle response current.

[0047] Based on the relationship between high-frequency current and rotor position, a phase-locked loop is used to estimate the rotor position, thereby determining the estimated rotor position and estimated speed.

[0048] This invention modifies the high-frequency voltage equation for single-axis injected high-frequency square wave voltage, determines the corresponding high-frequency current and rotor position relationship, and uses an improved phase-locked loop (PLL) to estimate the rotor position, achieving sensorless control. Based on the modified high-frequency voltage equation, this invention derives a new high-frequency current and rotor position relationship, determines an improved PLL, and reduces rotor position estimation errors in sensorless control.

[0049] Example 1

[0050] This embodiment discloses a sensorless control method for a reluctance motor based on high-frequency voltage correction, including:

[0051] Step S1: Sample the three-phase current output by the synchronous reluctance motor to obtain the visible three-phase current i a i b i c The αβ axis current i is obtained by performing a Clark transformation on the three-phase currents. α i β Discretize it and process the signal with a half-cycle lag to obtain the high-frequency αβ-axis current i. αh i βh :

[0052]

[0053] In the formula, i αh i βh For high-frequency αβ-axis current, i α (k), i β (k) represents the discrete signal of the αβ axis current.

[0054] The high-frequency αβ axis current i αh i βh Discretize formula (1), subtract the signal from the signal with its half-cycle lag, and obtain the high-frequency αβ axis current change value Δi. αh , Δi βh :

[0055]

[0056] In the formula, Δi αh , Δi βh For the high-frequency αβ axis current variation, i αh (k), i βh (k) represents the discrete signal of the αβ axis current.

[0057] The high-frequency αβ axis current variation signal Δi αh , Δi βh It contains rotor position information, and the specific principle is as follows:

[0058] Establish a mathematical model for a synchronous reluctance motor.

[0059]

[0060] In the formula, u d u q For dq axis voltage; i d i q L is the dq-axis current; d L q R is the direct-axis and quadrature-axis inductance; R is the resistance; ω e ω is the electric angular velocity.

[0061] Injecting a high-frequency voltage along the direct or quadrature axis, based on the mathematical model of a synchronous reluctance motor, the coupling part ω e L dh i dh -ω e L qh i qh and the voltage drop section Ri dh Ri qh The high-frequency voltage equation for a synchronous reluctance motor is relatively small and can be simplified to:

[0062]

[0063] In the formula, u dh u qh For high-frequency dq-axis voltage; i dh i qh L represents the dq-axis current under high-frequency excitation. dh L qh It is a high-frequency inductor for the dq axis.

[0064] Transform the high-frequency dq-axis voltage equation (4) to the αβ-axis system:

[0065]

[0066] In the formula, R(θ) e ) is the transformation matrix from the dq axis system to the αβ axis system;

[0067]

[0068] Transform (5) into a high-frequency αβ current equation:

[0069]

[0070] The high-frequency αβ current equation is obtained:

[0071]

[0072] In the formula, i αh i βh For αβ axis high-frequency current; u αh u βh For αβ axis high-frequency voltage; L avg =(L dh +L qh ) / 2 is the average inductance; L dif =(L dh -L qh ) / 2 is the differential inductance; θ e It is the angle between the rotating shaft system and the stationary shaft system, i.e., the rotor position angle.

[0073] Since the sampling frequency is higher than the high-frequency injected square wave frequency, di / dt can be approximated as Δi / Δt. From (8), the high-frequency αβ axis current change signal Δi can be obtained. αh , Δi βh :

[0074]

[0075] In the formula, Δi αh , Δi βh ΔT represents the difference in high-frequency current changes along the αβ axis, and ΔT represents the time difference corresponding to the current changes.

[0076] It can be seen that the high-frequency αβ axis current variation signal Δi αh , Δi βh It contains rotor position information θ e .

[0077] Step S2: Convert the high-frequency αβ axis current change signal Δi αh , Δi βh The estimated rotor position can be obtained through a phase-locked loop. and estimate rotor position

[0078] Traditional sensorless control using high-frequency square wave injection can be divided into two types: injecting a high-frequency square wave voltage signal along the d-axis and injecting a high-frequency square wave voltage signal along the q-axis. The phase-locked loop (PLL) structures obtained by these two methods are different. A detailed analysis follows:

[0079] Inject a high-frequency square wave voltage along the d-axis:

[0080]

[0081] In the formula, U in The voltage amplitude of the injected high-frequency square wave is denoted by k; k is the number of half-cycles of the high-frequency square wave injection period.

[0082] The high-frequency square wave voltage signal (10) of the d-axis is converted to the αβ-axis system to obtain the high-frequency voltage signal of the αβ-axis system:

[0083]

[0084] Substituting the high-frequency voltage signal (11) of the αβ shaft system into the equation (9) of the high-frequency αβ shaft current change signal, we obtain the expression for the relationship between the αβ shaft current change value and the rotor position:

[0085]

[0086] In the formula, the coefficient relating the d-axis injected current change to the rotor position is...

[0087] Then, the rotor position error expression is obtained, which is also the expression for determining the phase-locked loop based on the relationship between high-frequency current and rotor position:

[0088]

[0089] In the formula, θ err For rotor position error, To estimate the angle between the rotating coordinate system and the actual stationary coordinate system, i.e., to estimate the rotor position angle.

[0090] Inject a high-frequency square wave voltage along the q-axis:

[0091]

[0092] Convert the high-frequency square wave voltage signal (14) on the q-axis to the αβ-axis:

[0093]

[0094] Substituting the high-frequency voltage signal (15) of the αβ shaft system into the equation (9) of the high-frequency αβ shaft current change signal, we obtain the expression for the relationship between the αβ shaft current change value and the rotor position:

[0095]

[0096] In the formula, the coefficient relating the q-axis injected current change to the rotor position is...

[0097] The rotor position error expression is obtained, which is also the phase-locked loop expression determined based on the relationship between high-frequency current and rotor position:

[0098]

[0099] In the formula, θ err This represents the rotor position estimation error. To estimate the rotor position.

[0100] The rotor position error is adjusted via a PI controller to obtain the estimated rotational speed. Integrating the estimated rotational speed yields the estimated rotor position, which is the estimated angle between the rotating coordinate system and the actual stationary coordinate system, thus achieving sensorless control.

[0101] Step S3: Due to the effect of dq axis coupling, when a high-frequency square wave voltage is injected into the d-axis or q-axis alone, the high-frequency voltage value is not entirely a high-frequency square wave signal.

[0102] When a high-frequency square wave is injected along the d-axis, a small high-frequency voltage will be excited along the q-axis due to the coupling effect between the d and q axes. Therefore, the high-frequency voltage along the d-axis is modified as follows:

[0103]

[0104] Where δ is the minimum value.

[0105] Convert the high-frequency square wave voltage value (18) of the dq axis to the αβ axis:

[0106]

[0107] After correction, the corrected value of the high-frequency voltage of the αβ shaft system (19) is substituted into the equation (9) of the high-frequency αβ shaft current change signal to obtain the expression of the relationship between the αβ shaft current change value and the rotor position:

[0108]

[0109] In the formula, the coefficient relating the current change after d-axis injection voltage correction to the rotor position is... To improve the compensation angle of the phase-locked loop structure;

[0110] The rotor position error expression is obtained as follows:

[0111]

[0112] When a high-frequency square wave is injected along the q-axis, a small high-frequency voltage will be excited along the d-axis due to the coupling effect of the d-q axis. Therefore, the high-frequency voltage along the q-axis is modified as follows:

[0113]

[0114] Convert the high-frequency square wave voltage value of the dq axis to the αβ axis:

[0115]

[0116] Substituting the correction value (23) of the high-frequency voltage of the αβ shaft system into the equation (9) of the high-frequency αβ shaft current change signal, we obtain the expression for the relationship between the αβ shaft current change value and the rotor position:

[0117]

[0118] In the formula, the coefficient relating the current change after q-axis injected voltage correction to the rotor position is... To improve the compensation angle of the phase-locked loop structure.

[0119] The rotor position error expression is obtained as follows:

[0120]

[0121] When performing sensorless control with single-axis injection, injection can be performed on either the d-axis or the q-axis. The two traditional phase-locked loop structures are different, and neither takes into account the coupling effect of the synchronous reluctance motor. The high-frequency square wave voltage signal is not a high-frequency voltage value, so the two cases are analyzed separately.

[0122] Therefore, when injecting a high-frequency square wave along the d-axis, the improved phase-locked loop structure, derived from the modified high-frequency voltage expression, yields the rotor position error θ. err The rotor position error is adjusted by PI control to obtain the estimated speed, and the estimated rotor position is obtained by integrating the estimated rotor position, that is, the angle between the rotating coordinate system and the actual stationary coordinate system, thus realizing sensorless control.

[0123] When injecting a high-frequency square wave along the q-axis, the improved phase-locked loop structure is obtained through the modified high-frequency voltage expression, and the rotor position error θ is obtained. err The rotor position error is adjusted by PI control to obtain the estimated speed, and the estimated rotor position is obtained by integrating the estimated rotor position, that is, the angle between the rotating coordinate system and the actual stationary coordinate system, thus realizing sensorless control.

[0124] An improved phase-locked loop structure is derived from the rotor position error expression. The output rotor position error is adjusted by a PI controller to obtain the estimated speed, and the estimated speed is integrated to obtain the estimated rotor position.

[0125] This embodiment of the sub-technical solution can reduce rotor error, making the estimated rotor position closer to the actual rotor position, and achieving more accurate sensorless control.

[0126] Combination Figure 1 , Figure 2 and Figure 4 , Figure 5 , Figure 1 and Figure 2 A high-frequency square wave signal is injected into the d-axis, and a modified phase-locked loop is used for sensorless control. The three-phase current output from the synchronous reluctance motor is sampled to obtain three-phase current data. The three-phase current is then transformed using a Clarke transform to obtain the αβ-axis current i. α and i β The high-frequency αβ-axis current i is obtained by processing the current and its lag half-cycle signal. αh and i βh The αβ-axis current is transformed using the PARK transformation to obtain the dq-axis current i. d and i q The fundamental frequency dq-axis current i is obtained by processing this current and its lag half-cycle signal. df and i qf . will i αh and i βh Subtracting the hysteresis current from the hysteresis current yields Δi. αh and Δiβh The obtained current change is passed through Figure 2 An improved phase-locked loop (PLL) is used to obtain the estimated rotational speed and estimated rotor position. The difference between the estimated speed and the reference speed is calculated, and the reference torque at this moment is obtained through the speed loop. The dq-axis current distribution is determined according to the maximum torque-to-current ratio (MTPA) control, and the dq-axis voltage is obtained through the current loop. The signal is then processed by SVPWM to obtain the DC voltage source U. dc The processed switching signals are used to control the synchronous reluctance motor for sensorless control. Figure 4 and Figure 5 A high-frequency square wave signal is injected into the q-axis, and a modified phase-locked loop is used for sensorless control.

[0127] refer to Figure 3 and Figure 6 As one embodiment of the present invention, a sensorless control method for a synchronous reluctance motor based on an improved phase-locked loop structure is provided. To further verify the beneficial effects of the present invention, a simulation experiment is conducted below for scientific demonstration:

[0128] like Figure 3 The figure shown is a Simulink simulation diagram of the rotor position error of a synchronous reluctance motor based on a sensorless control method with an improved phase-locked loop structure. From... Figure 3 It can be seen that during steady-state operation, the difference between the estimated rotor position and the actual rotor position obtained by the traditional phase-locked loop is 0.1 (i.e. 5.7°). By using the improved phase-locked loop, the average error between the estimated rotor position and the actual rotor position can be reduced to 0.

[0129] like Figure 6 The figure shown is a Simulink simulation diagram of the rotor position error of a synchronous reluctance motor based on a sensorless control method with an improved phase-locked loop structure. From... Figure 3 It can be seen that during steady-state operation, the difference between the estimated rotor position and the actual rotor position obtained by the traditional phase-locked loop is 0.06 (i.e. 3.4°). By using the improved phase-locked loop, the average error between the estimated rotor position and the actual rotor position can be reduced to 0.

[0130] Example 2

[0131] The purpose of this embodiment is to provide a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of the above-described method.

[0132] Example 3

[0133] The purpose of this embodiment is to provide a computer-readable storage medium.

[0134] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, performs the steps of the above method.

[0135] Example 4

[0136] The purpose of this embodiment is to provide a sensorless control system for a reluctance motor based on high-frequency voltage correction, including:

[0137] The three-phase current data sampling module is configured to sample the three-phase current output by the synchronous reluctance motor to obtain three-phase current data.

[0138] The three-phase current data processing module is configured to transform the three-phase currents to obtain the αβ axis currents.

[0139] The high-frequency αβ-axis current is obtained by processing the αβ-axis current and its hysteresis half-cycle signal.

[0140] The αβ axis current is transformed to obtain the dq axis current, and the fundamental frequency dq axis current is obtained by processing the current and its half-cycle lag signal.

[0141] The change in current is obtained by subtracting the high-frequency αβ-axis current from the hysteresis current.

[0142] The speed and rotor position estimation module is configured to process the obtained current change through a phase-locked loop structure to obtain the estimated speed and estimated rotor position;

[0143] The control module is configured to process the estimated rotational speed and estimated rotor position to obtain a switching signal, which is used to control the synchronous reluctance motor.

[0144] Example 5

[0145] The purpose of this embodiment is to provide a computer program product containing instructions that, when run on a computer, cause the computer to perform the methods and functions involved in any of the above embodiments.

[0146] The steps and methods involved in the apparatus of the above embodiments correspond to those in Embodiment 1. For specific implementation details, please refer to the relevant description section of Embodiment 1. The term "computer-readable storage medium" should be understood as a single medium or multiple media including one or more instruction sets; it should also be understood as including any medium capable of storing, encoding, or carrying an instruction set for execution by a processor and enabling the processor to perform any of the methods in this invention.

[0147] Those skilled in the art will understand that the modules or steps of the present invention described above can be implemented using general-purpose computer devices. Optionally, they can be implemented using computer-executable program code, thereby allowing them to be stored in a storage device for execution by a computer device, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. The present invention is not limited to any particular combination of hardware and software.

[0148] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A sensorless control method for reluctance motors based on high-frequency voltage correction, characterized in that, include: The three-phase current output by the synchronous reluctance motor is sampled to obtain the three-phase current data; The three-phase current is transformed to obtain αβ shaft current; αβ High-frequency signals are obtained by processing the shaft current and its lag half-cycle signal. αβ shaft current; αβ The shaft current is obtained through transformation dq The fundamental frequency is obtained by processing the shaft current and its lag half-cycle signal. dq Shaft current; this high frequency αβ shaft current and this high frequency αβ The change in current is obtained by subtracting the hysteresis current from the axial current. The obtained current change is processed through a phase-locked loop structure to obtain an estimated speed and an estimated rotor position; the estimated speed and estimated rotor position are processed to obtain a switching signal, which is used to control the synchronous reluctance motor. Alone d When a high-frequency square wave voltage is injected into the shaft; The obtained current change is processed through a phase-locked loop structure to obtain the estimated speed and estimated rotor position. d The shaft high-frequency voltage correction is expressed as follows: ， in, δ It is the minimum value. u dh , u qh High frequency d, q shaft voltage, U in To inject high-frequency square wave voltage amplitude, k Inject half-cycles of a high-frequency square wave; based on d Shaft high-frequency voltage correction expression, rotor position error expression: Where, Δ i αh Δ i βh High frequency α、β shaft current variation value θ e The angle between the rotating shaft system and the stationary shaft system, i.e., the rotor position angle. To estimate the angle between the rotating coordinate system and the actual stationary coordinate system, i.e., to estimate the rotor position angle, θ err K represents the rotor position error. d2 for d The coefficient relating current change to rotor position after shaft injection voltage correction. , φ d To improve the compensation angle of the phase-locked loop structure, φ d =arctan(δL dh / L qh )，L dh , L qh They are respectively d shaft and q The high-frequency inductance of the shaft, where ΔT is the time difference corresponding to the change in current.

2. The sensorless control method for a reluctance motor based on high-frequency voltage correction as described in claim 1, characterized in that, The estimated rotational speed and estimated rotor position are processed to obtain the switching signal, specifically: The difference between the estimated speed and the reference speed is calculated, and the maximum torque-current ratio is used for control. dq Shaft current distribution is obtained through a current loop. dq Shaft voltage is a switching signal obtained by processing the signal to a DC voltage source, which is used to control the synchronous reluctance motor.

3. The sensorless control method for a reluctance motor based on high-frequency voltage correction as described in claim 1, characterized in that, Alone q When a high-frequency square wave voltage is injected into the shaft, q The shaft high-frequency voltage correction is expressed as follows: ； in, δ It is the minimum value. u dh , u qh High frequency d, q shaft voltage, U in To inject high-frequency square wave voltage amplitude, k Inject half-cycles of a high-frequency square wave; Rotor position error expression: Where, Δ i αh Δ i βh High frequency α、β shaft current variation value θ e The angle between the rotating shaft system and the stationary shaft system, i.e., the rotor position angle. To estimate the angle between the rotating coordinate system and the actual stationary coordinate system, i.e., to estimate the rotor position angle, θ err For rotor position error, φ q To improve the compensation angle of the phase-locked loop structure, K q2 for q The coefficient relating current change to rotor position after shaft injection voltage correction. , φ q To improve the compensation angle of the phase-locked loop structure, φ q =arctan(δL qh / L dh )，L dh , L qh They are respectively d shaft and q The high-frequency inductance of the shaft, where ΔT is the time difference corresponding to the change in current.

4. A sensorless control system for a reluctance motor based on high-frequency voltage correction, employing the sensorless control method for a reluctance motor based on high-frequency voltage correction as described in any one of claims 1-3, characterized in that, include: The three-phase current data sampling module is configured to sample the three-phase current output by the synchronous reluctance motor to obtain three-phase current data. The three-phase current data processing module is configured to transform the three-phase current to obtain... αβ shaft current; Will αβ High-frequency signals are obtained by processing the shaft current and its lag half-cycle signal. αβ shaft current; Will αβ The shaft current is obtained through transformation dq The fundamental frequency is obtained by processing the shaft current and its lag half-cycle signal. dq shaft current; The high frequency αβ shaft current and this high frequency αβ The change in current is obtained by subtracting the hysteresis current from the axial current. The speed and rotor position estimation module is configured to process the obtained current change through a phase-locked loop structure to obtain the estimated speed and estimated rotor position; The control module is configured to process the estimated rotational speed and estimated rotor position to obtain a switching signal, which is used to control the synchronous reluctance motor.

5. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the method of any one of claims 1 to 3.

6. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps of the method described in any one of claims 1-3.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it performs the steps of the method described in any one of claims 1-3 above.

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