44 results about "Stator inductance" patented technology

The invention discloses a current harmonic disturbance suppression method and suppression system for a permanent magnet synchronous motor. The method comprises the following steps: acquiring voltage and current signals of an electrical loop phasor test in the operation of the motor; an inductance identification algorithm based on high-frequency response is adopted, high-frequency excitation signals are injected, current response is monitored, and stator inductance parameters are calculated; constructing a multi-synchronous rotating coordinate system based on the parameter, and decomposing the current signal to obtain each harmonic current component; building a fuzzy full-order sliding mode observer, inputting an inductance parameter, voltage data and a harmonic current component, and dynamically adjusting a sliding mode surface parameter to observe the position and the rotating speed of a rotor; independently controlling each harmonic current adjusting channel under a multi-coordinate system in combination with observation information, and generating a compensation control signal; and the synthesized master control signal is output to the driving circuit. The system comprises six units, and the method and the system can accurately obtain parameters, efficiently decompose harmonic waves, accurately observe states, realize multi-frequency harmonic disturbance suppression, and improve motor operation stability and efficiency.

An offline flux-linkage and moment-of-inertia identification method for a permanent magnet synchronous motor, the method comprising: on the premise that a pole-pair number Pn, a stator resistance Rs, and a stator inductance Ls of a motor are known, tuning PI parameters of a current loop and a speed loop; in a dual closed-loop mode for current and speed, identifying the flux linkage of the motor by using a recursive least squares method with a forgetting factor; in a current closed-loop mode, injecting a low-frequency current signal having progressively increasing amplitude and frequency, and determining a current magnitude required to start the motor and rotate same to a preset rotation speed threshold; and using acceleration / deceleration methods to identify the moment of inertia of the motor, wherein the motor is rotated forward and backward and identification is performed multiple times, and a median value is obtained by ranking to improve identification accuracy. The flux-linkage and moment-of-inertia identification processes are simple, stable, and reliable, the accuracy of identification results is high, one-click parameter identification can be achieved, and the method has a wide range of applications and is applicable to permanent magnet synchronous motors with various parameters.

The invention provides an MRAS permanent magnet synchronous motor parameter online identification method based on BP neural network optimization, and the method comprises the steps: constructing two BP neural network models, carrying out the offline training optimization of the two models, and obtaining an optimal neural network model which can accurately predict the flux linkage of a rotor and the inductance of a stator; based on an MRAS step-by-step identification strategy, two-stage motor parameter step-by-step identification units are built, the two optimal neural network models are embedded into the corresponding motor parameter step-by-step identification units, and based on the problem that the stator resistance identification effect of the BP neural network is poor, the two optimal neural network models are embedded into the corresponding motor parameter step-by-step identification units; according to the invention, the BP neural network and the adaptive rate unit are established in the second MRAS parameter identification unit, and the online dynamic identification of the stator resistance and the stator inductance is realized through the combination of the BP neural network and the adaptive rate unit. According to the method, an off-line training-on-line identification mode is adopted, the complex parameter setting process in a traditional method is avoided, the identification efficiency is remarkably improved, and the identification result is accurate.

The invention discloses a permanent magnet synchronous motor control method, system and device based on H infinity filter, a medium and a product, and relates to the field of motors, and the method comprises the steps: optimizing the parameters of a permanent magnet synchronous motor at the current moment based on the H infinity filter; the permanent magnet synchronous motor parameters comprise stator resistance, stator inductance and permanent magnet flux linkage of the permanent magnet synchronous motor; based on the output rotating speed and the reference rotating speed of the permanent magnet synchronous motor at the current moment, a PI controller is adopted to determine reference stator current; based on the reference stator current, weak magnetic control is adopted to generate a stator current component; based on the stator current component and the optimized parameters of the permanent magnet synchronous motor, a mathematical model of the permanent magnet synchronous motor is adopted to calculate a reference stator voltage component; and converting the reference stator voltage component into a switching pulse of an inverter through space vector pulse width modulation so as to drive the permanent magnet synchronous motor. According to the invention, the control precision and robustness of the permanent magnet synchronous motor can be improved.

Synchronous electric machine with fixed claw inductor. One aspect of the invention relates to a synchronous electric machine (M1, M1', M1'', M1''', M2, M2', M20, M21, M20') comprising: a first stator claw inductor (1, 1', 4, 4') comprising a ferromagnetic claw body (11, 41) comprising a number Pe of poles, a first stator armature (2, 2', 2u, 5, 5', 5u) comprising a number Pa of poles different from the number Pe, a ferromagnetic rotor (3, 6, 6') comprising: a rotation axis (X), a first set of ferromagnetic parts (30, 30u, 60, 60u) comprising a number Ns of parts regularly distributed around the rotation axis (X), the number Ns being equal to the sum of or the difference between Pa / 2 and Pe / 2, the set of ferromagnetic parts (30, 30u, 60, 60u) being located between the first stator inductor with claws (1, 1', 4, 4') and the first stator armature. Figure to be published with the abbreviation: Figure 2

The invention discloses a simulation modeling method and device for a permanent magnet synchronous motor. The simulation modeling method comprises the following steps: establishing a state equation of the permanent magnet synchronous motor; searching in a preformed first two-dimensional array by taking the stator current as an input quantity to obtain corresponding stator inductance; calculating a stator flux linkage differential value according to a state equation of the permanent magnet synchronous motor and the found stator inductance; integrating the stator flux linkage differential value to obtain a stator flux linkage; and obtaining the adjusted stator current according to the obtained stator flux linkage and the relational expression between the flux linkage and the current. According to the application, the MTPA function can be realized, the values of the inductance and the flux linkage are reduced along with the increase of the current, the MTPA state and the weak magnetic state working area of the real motor can be simulated, and the simulation motor is ensured to be close to the operation condition of the actual motor to the greatest extent.

A transmission characteristic parameter identification method for a ball screw feeding system comprises the following steps: in the normal operation process of the ball screw feeding system, acquiring voltage, current, rotating speed and other signals through a servo motor and a driving system thereof, and realizing online identification of key electromagnetic parameters and mechanical parameters in stages; under the static working condition of the motor, controlled voltage excitation is applied, stator current is measured, and identification of stator winding resistance and stator inductance is completed; under the steady-state operation condition, the flux linkage amplitude of the permanent magnet is calculated based on a q-axis voltage equation; under a dynamic operation condition, a friction torque model is established through segmented constant-speed operation, a rotor motion equation is combined, a recursive least square algorithm with a forgetting factor is introduced, and online identification of the equivalent rotational inertia of the system is realized; according to the method, complete and accurate transmission characteristic parameters can be obtained in the ball screw feeding system, the identification process is stable, the calculation complexity is low, and the method is suitable for being embedded into a servo control system.

The invention relates, in one aspect, to a synchronous electric machine (M1, M1 ', M1' ', M1' '', M2, M2 ', M20, M21, M20') comprising: a first claw-pole stator inductor (1, 1 ', 4, 4') comprising: a claw-pole ferromagnet (11, 41) comprising Pe poles; a first stator armature (2, 2 ', 2u, 5, 5', 5u), the number of poles Pa of which is different from the number of poles Pe; a ferromagnetic rotor (3, 6, 6 ') comprising: an axis of rotation (X); comprising Ns ferromagnetic elements uniformly distributed along the axis of rotation (X), the Ns being equal to the sum or difference between Pa / 2 and Pe / 2, the set of ferromagnetic elements (30, 30u, 60, 60u) being located between the first claw pole stator inductor (1, 1 ', 4, 4') and the first stator armature (2, 2 ', 2u, 5, 5', 5u).

The embodiment of the invention provides a rotor position determination method and device of a synchronous reluctance motor, equipment and a medium. The method comprises the following steps: acquiring stator data at the current moment; wherein the stator data comprises stator voltage and stator current; based on an equivalent transmission line model, according to the stator data at the current moment and the incident voltage at the previous moment, determining the back electromotive force at the current moment; wherein the equivalent transmission line model represents a physical model for enabling stator inductance to be equivalent to a short-circuit transmission line, the equivalent transmission line model is used for determining back electromotive force, the back electromotive force represents the magnetic resistance characteristic of a rotor of the synchronous reluctance motor, and the incident voltage represents the initial state of voltage waves propagating in the short-circuit transmission line; determining rotor position information at the current moment according to the back electromotive force at the current moment; wherein the rotor position information comprises a rotor electrical angle and a rotor electrical angular velocity. The method is used for achieving the effect of improving the adaptability and precision of determining the rotor position of the synchronous reluctance motor.

The invention belongs to the field of permanent magnet synchronous motor control, and discloses a low-speed region position sensorless control method and system, and the method comprises the steps: obtaining the high-frequency current response of a quadrature axis in a controlled motor; the high-frequency current response is a high-frequency current response of a quadrature axis in the collected motor after high-frequency square wave voltage is injected into a direct axis of the controlled motor, and the variable quantity of the high-frequency current response is calculated according to the high-frequency current response; calculating an angle error by using the injected high-frequency square wave voltage, the stator inductance difference, the variable quantity of the high-frequency current response and the sampling period of the current; and integrating the angle error, using an integral result to update the rotor position estimation value, and continuously correcting the angle error through feedback until the angle error tends to zero to obtain the rotor estimation position. Accurate control over the motor without the position sensor in the low-speed area is achieved.

This application provides a method, system, device, and medium for designing output filter parameters for a frequency converter, relating to the field of frequency converter filtering technology. The method includes: obtaining target parameters of the frequency converter; determining a first resonant frequency constraint condition for the output filter in the frequency converter based on the rated fundamental frequency and pulse width modulation switching frequency; determining the total control delay based on the pulse width modulation switching frequency, and determining a second resonant frequency constraint condition for the output filter based on the total control delay and the controller parameters of the frequency converter, thereby determining the resonant frequency range of the output filter; determining the range of filter capacitor parameters for the output filter based on the rated voltage, rated current, and rated fundamental frequency; and determining the target resonant frequency, target filter capacitor parameters, and target filter inductance parameters for the output filter based on the resonant frequency range, the filter capacitor parameter range, and the motor stator inductance. This application can effectively suppress the resonance of the frequency converter output filter and effectively avoid the risk of instability.

The invention discloses an asymmetric half-bridge control method for a driving motor of an electric forklift, and the method comprises the steps: employing an asymmetric half-bridge as an inverter topology, and enabling the asymmetric half-bridge to comprise a left bridge arm and a right bridge arm; respectively constructing bridge arm models when the output ends of the left bridge arm and the right bridge arm are high levels, so as to obtain an expression of stator current of the driving motor; establishing a state equation taking the filter capacitor charge, the motor stator inductance magnetic flux and the filter inductance magnetic flux as state variables; and determining a stator current reference value according to the driving working condition of the forklift, setting a cost function, and selecting a switching control signal enabling the cost function to be minimum so as to control the switching action of the asymmetric half-bridge. According to the invention, the asymmetric half-bridge is used as the inverter topology to avoid the bridge arm direct connection problem, the state matrix of the electric drive system is obtained by carrying out overall modeling on the asymmetric half-bridge inverter, the torque ripple during the working of the motor can be effectively reduced, and the working stability of the motor is ensured.

The present application is applicable to the field of motor control technology and provides a permanent magnet synchronous motor control method and device. The above permanent magnet synchronous motor control method first obtains the stator current of the motor, where the stator current is any two-phase current in the three-phase current of the motor stator. The stator current is then subjected to a CLARKE transformation to obtain the current component of the stator current in a two-phase stationary coordinate system, and the rotor position and rotor speed of the motor are calculated based on the current component, voltage component and motor body parameters. The motor body parameters include stator inductance, stator phase resistance and back electromotive force constant. The voltage component is the voltage component of the stator voltage in a two-phase stationary coordinate system. Finally, a motor control signal is generated based on the rotor position and rotor speed. The motor control signal is used to control the rotation of the motor. This method can obtain the position and speed of the rotor without installing a physical rotor position sensor, and can achieve stable and reliable operation of the permanent magnet synchronous motor within the full speed range.

The application discloses a motor driving switch current surge modeling and model predictive control method, and belongs to the technical field of power generation, power transformation or power distribution. The modeling method comprises the following steps: establishing a motor voltage equation and a magnetic motive force equation; calculating an expression of motor stator magnetic motive force about current and permanent magnet flux linkage; calculating an expression of stator magnetic resistance about stator inductance; simultaneously solving the magnetic circuit equation and the voltage equation, and substituting the magnetic motive force expression to calculate the stator flux linkage expression; substituting the stator flux linkage expression into the voltage equation, and replacing the equivalent magnetic induction coefficient before the voltage differential term with the differential magnetic induction coefficient to obtain a permanent magnet motor model considering the switch current surge. The modeling method effectively improves the motor modeling accuracy. The application also provides a model predictive control method and a measurement method for quantitatively describing the differential magnetic induction coefficient of the switch current surge, which can effectively improve the operation performance of the motor variable current control system and improve the practicability of the modeling method.

The invention discloses a permanent magnet synchronous motor sensorless control parameter identification method, which comprises the following steps of: S1, acquiring a permanent magnet flux linkage error by utilizing a flux linkage observer, injecting a high-frequency sinusoidal signal on a d axis, and realizing identification of stator winding resistance and stator inductance of a permanent magnet synchronous motor based on the error; s2, the inductance identification value and the resistance identification value are substituted into a position-free observer and a current controller, so that high-precision control over the motor is achieved; and S3, when the q-axis current changes, inductance identification is executed again so as to compensate inductance parameter changes caused by factors such as magnetic saturation and the like, and the control precision is ensured. The permanent magnet synchronous motor driver can be applied to a general permanent magnet synchronous motor driver, and has high application value and economic value. According to the method, the under-rank problem of non-position parameter identification of the permanent magnet synchronous motor is solved, the estimation precision is improved, and reliable operation and higher-performance control of a permanent magnet synchronous motor driving system are realized.

This invention discloses an inductance estimation method, system, apparatus, computer device, and readable storage medium. The method includes calculating the permanent magnet linkages along the α-axis and β-axis of the compressor, and calculating the rotor position θ(n) based on the permanent magnet linkages; calculating the actual operating speed N(n) of the compressor based on a preset control cycle and the rotor position θ(n); and calculating the phase current magnitude I of the compressor based on a preset sub-current. s (n), based on the actual operating speed N(n) and the phase current magnitude I s (n) The compressor operating speed N when the phase current magnitude is maximized. s (n max The compressor operating speed N when the phase current modulus is extremely small. s (n min The compressor operating speed N is based on the maximum phase current magnitude. s (n max The compressor operating speed N when the phase current modulus is extremely small s (n min This method estimates the adjustment amount of the stator inductance at the current moment and estimates the inductance of the stator inductance at the next moment based on the current stator inductance and the adjustment amount. This method utilizes the physical quantities of vector control to improve the accuracy of stator inductance estimation.

The present disclosure provides a method, device and medium for identifying parameters of a boost motor of a distributed electric propulsion system, which belongs to the field of computing technology and specifically includes: Step 1, obtaining the stator current i of the boost motor d ,i q , stator voltage u d ,u q and electrical angular velocity ω e ; Step 2, the stator current i d and i q and the stator voltage u d and u q Input the improved Newton-Raphson optimizer to obtain the process noise matrix Q and measurement noise matrix R of the extended Kalman filter of the lift motor parameter identification model; Step 3, the stator current i d ,i q , stator voltage u d ,u q , electrical angular velocity ω e The process noise matrix Q and the measurement noise matrix R are input into the extended Kalman filter to obtain the identification values ​​of the permanent magnet flux, stator resistance, and stator inductance of the boost motor. The disclosed solution improves the identification efficiency, accuracy, and adaptability.

The present invention discloses a motor robust model predictive control method based on linear fitting, comprising: (1) establishing a motor current increment prediction model; (2) establishing a stator inductance estimation model to obtain a stator inductance calculation matrix, and calculating an eigenvector corresponding to the minimum eigenvalue of the stator inductance calculation matrix; (3) calculating a stator inductance estimation value based on the eigenvector; (4) establishing a motor current increment prediction model based on the stator inductance estimation value; (5) constructing a cost function from the motor current increment prediction model based on the stator inductance estimation value, the cost function is used to calculate an optimal stator voltage increment, and finally the optimal stator voltage increment is added to the stator voltage applied at the current control moment to obtain the optimal stator voltage at the next control moment. The present invention estimates the stator inductance by using a linear fitting method based on orthogonal regression, thereby improving the robustness of the model predictive control while avoiding excessive calculation amount and complex parameter setting work.

A flux estimator for estimating an air-gap flux in an electric motor includes a resistance compensation stage having a first multiplying digital-to-analogue converter, and an inductance compensation stage having a second multiplying digital-to-analogue converter. The flux estimator determines a first gain (Ku) for compensating for a stator resistance (Ra); and a second gain (KLa) for compensating a stator inductance (La). The first gain (Ku) is supplied to the first multiplying digital-to-analogue converter to generate a first output signal (VIAR) providing a scaled representation of the voltage drop across the stator resistance (Ra) per phase. The second gain (KLa) is supplied to the second multiplying digital-to-analogue converter to generate a second output signal (IA_LA) providing a scaled representation of the stator inductance (La) per phase. An air-gap flux estimation signal (PSI_MON) is generated in dependence on the first output (VIAR) and the second output (IA_LA).

This invention provides a method and control device for self-heating a lithium battery in an electric vehicle when stationary. The self-heating method includes the following steps: a motor controller uses a sinusoidal pulse width modulation method combined with a current closed-loop control strategy to control a three-phase inverter; by controlling the alternating switching of a pair of specific spatial switching vectors, the two-phase stator windings of the permanent magnet synchronous motor are connected in parallel and then in series with the third-phase stator winding, effectively reducing the three-phase inverter to a single-phase inverter at the hardware topology physical level; under this equivalent topology, the stator inductance of the permanent magnet synchronous motor is used as an energy storage element to achieve repeated charging and discharging with the lithium battery; simultaneously, the alternating switching of specific spatial switching vectors is controlled to physically fix the spatial direction of the stator's composite magnetomotive force, passively aligning the rotor's magnetomotive force with the stator's composite magnetomotive force, thereby keeping the motor stationary; the corresponding control device consists of the above-mentioned main circuit and the motor controller executing the control program, and the main circuit does not require additional power switching devices, achieving zero additional hardware cost and zero additional space occupation, eliminating dependence on rotor position sensors, reducing system complexity and improving safety during parking heating.

Method (200) for controlling a multiphase rotating field machine in the event of an interruption of the current in at least one phase of the rotating field machine, comprising: Receiving (220) control parameters of the rotating field machine control and a direction of rotation of the rotor; Calculating (230) a position parameter corresponding to a plurality of possible rotor positions of the rotor based on the control parameters, wherein the calculation (230) of the position parameter is based on the equation: 1 3 ⋅ ψ PM ∫ [ ( PWM 2 − PWM 3 ) ⋅ U dc − 2 ⋅ R s ⋅ I s 2 − 2 ⋅ L s ⋅ d I s 2 dt ] dt = sin ( θ el ) This occurs when the first of three phases of the rotating field machine fails, or based on the equation: 1 3 ⋅ ψ PM ∫ [ ( PWM 1 − PWM 3 ) ⋅ U dc − 2 ⋅ R s ⋅ I s 1 − 2 ⋅ L s ⋅ d I s 1 dt ] dt = cos ( θ el − π 6 ) This occurs when a second of the three phases of the rotating field machine fails, or based on the equation: 1 3 ⋅ ψ PM ∫ [ ( PWM 1 − PWM 2 ) ⋅ U dc − 2 ⋅ R s ⋅ I s 1 − 2 ⋅ L s ⋅ d I s 1 dt ] dt = cos ( θ el + π 6 ) This occurs when a third of three phases of the rotating field machine fails, where each Ψ PM a rotor flux, PWMi a pulse-width modulated signal for the i-th phase, Udc an intermediate circuit voltage of an inverter, R s a stator resistor, I si a phase current of the i-th phase, and L s a stator inductance of the rotating field machine; and Determining (240) an actual rotor position based on the position parameter and the direction of rotation.

This invention provides a method for estimating the static initial position of a permanent magnet synchronous motor and a method for identifying the stator inductance. Rated positive and negative pulse voltages are sequentially injected into the windings of phases AB, BC, and CA of the motor. The response current values ​​of each phase under the rated positive and negative pulse voltages are recorded, and the current response difference ΔI between phases AB, BC, and CA in the three-phase stationary coordinate system is calculated. ab ΔI bc and ΔI ca The Clark transformation is performed on the current response difference between each phase to obtain the current response difference ΔI in the α-β axis two-phase stationary coordinate system. α and ΔI β Based on ΔI α and ΔI β Calculate the initial rotor position θ. Based on the calculated initial rotor position, calculate the stator inductance of the permanent magnet synchronous motor. This invention obtains the rotor position directly from the current pulse response through coordinate transformation and solution, eliminating intermediate conversion steps, reducing data loss, and ensuring data accuracy.

The application provides an AC motor rotor position estimation method based on inverter pulse width modulation wave excitation. A two-level voltage source inverter is modulated by a space vector voltage, and the voltage vector average values during the zero and non-zero vector action periods in the two adjacent PWM periods are calculated. Meanwhile, the current during the zero voltage vector action period at the start / half / end time of each period is measured, the average current slope in the two "half PWM periods" in each period is calculated, and the rotor position calculation formula is obtained to estimate the rotor position of the AC motor in the zero speed to high speed range. The application directly extracts the rotor position information from the stator inductance matrix by using the salient pole effect of the motor itself, realizes the rotor position estimation in the zero speed to high speed range, and is not affected by the change of the counter electromotive force amplitude. The application does not need to inject a high frequency signal, avoids additional loss, and performs current sampling at the start / end time and half cycle time of the PWM period, greatly simplifies the calculation of the current change rate.

The embodiment of the invention relates to a non-intrusive method for identifying parameters of an induction motor and electronic equipment. The method comprises the following steps: acquiring a transient voltage, a transient current and a starting process duration of the starting process of the induction motor under a synchronous dq coordinate; obtaining a feasible region of an estimator of the resistance of the stator winding and an estimator of the leakage inductance of the stator winding, and generating a two-dimensional search grid; equivalent resistance and equivalent reactance of the induction motor at a real load operation point are obtained; constructing an induction motor impedance circle by using the feasible region and the equivalent resistance and the equivalent reactance at the real load operation point; and calculating an objective function of each grid point in the two-dimensional search grid, searching stator resistance and stator inductance of a global optimal grid point enabling the objective function value to be minimum, and obtaining an impedance parameter of the induction motor. According to the embodiment of the invention, the impedance circle diagram of the induction motor is adopted, the number of solving equations is increased, the difficulty of impedance parameter solving is reduced, and non-intrusive parameter identification is realized.

The invention relates to a speed sensorless control method of a doubly-fed motor for a variable-speed pumping and storage system, which can be applied to the technical field of electric power. The method comprises the steps of performing parameter online identification on the doubly-fed motor, and outputting stator resistance, stator inductance, rotor resistance, rotor inductance and mutual inductance after identification; establishing a rotor flux linkage reference model and a rotor flux linkage adaptive model according to the identified stator resistance, stator inductance, rotor resistance, rotor inductance and mutual inductance, and observing a stator flux linkage angle and a rotor position angle through the rotor flux linkage reference model and the rotor flux linkage adaptive model; performing vector control on the stator flux linkage angle and the rotor position angle, and outputting a driving signal; the driving signal is used for controlling the doubly-fed motor. By adopting the method, the control precision of the doubly-fed motor can be improved.

The present invention discloses a robust sliding mode current control method and system for a permanent magnet motor long line drive system, belonging to the field of power electronics and power transmission. First, the state variables of the system are sampled, and the reference of the filter inductor current is calculated by using the steady-state characteristics of the filter capacitor voltage dynamic model; then the resonant current component is extracted by using a high-pass filter, and the reference for suppressing the resonance of the filter inductor current is calculated; then the discrete state equation of the filter inductor current is established by using the second-order Taylor expansion method; a discrete sliding mode switching function matrix is designed based on the tracking error of the reference for suppressing the resonance of the filter inductor current; a robust sliding mode control command is obtained based on the discrete sliding mode switching function matrix; the robust sliding mode control command is transformed to the αβ coordinate system through Park inverse transformation and sent to the space vector modulation module to generate pulse signals to be applied to the inverter. The present invention can effectively suppress the resonance phenomenon of the permanent magnet motor long line drive system and improve the robustness of the system to the stator inductance parameter mismatch disturbance.

The present invention discloses an online identification method for the stator inductance of an ultra-high-speed permanent magnet synchronous motor, comprising the following steps: obtaining the phase current i of the motor; a and i b Perform Clark transformation to obtain the stator current i in the two-phase stationary coordinate system α and i β ; According to the stator current i in the two-phase stationary coordinate system α and i β And the voltage command u in the two-phase stationary coordinate system α and u β , obtaining sample point information; performing sample preprocessing to obtain identification sample points; and performing online stator inductance parameter identification to obtain the stator inductance value. The present invention also discloses an online identification system for the stator inductance of an ultra-high-speed permanent magnet synchronous motor. The present invention is designed based on an inductance parameter equation that does not include rotor position information. The entire identification process does not require rotor position information, which can improve the reliability of online stator inductance identification under position sensorless control conditions.

The invention provides an amphibian human welding robot chassis control method based on magnetic wheel driving. A dead-beat fast calculation three-vector model is adopted for conducting predictive control on a motor; the input of the dead-beat fast calculation three-vector model is a target current; a current parameter Pr (k) = [R Ls psi f] T in the dead-beat fast calculation three-vector model is obtained through real-time estimation by adopting a forgetting factor recursive least square method parameter identification algorithm; wherein R is the stator resistance of the motor; ls is motor stator inductance; psi f is motor rotor flux linkage; the forgetting factor recursive least square method parameter identification algorithm is realized based on a q-axis discretization mathematical model and a least square method recursive formula with forgetting factors. According to the method, the current harmonic distortion rate can be effectively reduced, the torque stability can be improved, the influence of temperature and other external environment changes on motor parameters can be restrained, accurate parameter identification is achieved, control can be better conducted through a model prediction control algorithm, the robot chassis can move more stably, and the welding stability is guaranteed.

The invention relates to a device (101, 300) for determining an estimated value (314, 315) of a measurement offset of a phase current sensor (115) for a phase current (112) of an electric machine (103). The device (101, 300) is configured to determine a measured value (215) of a control error of a current controller (200) for adjusting a phase current (112) of an electric machine (103) at a point in time. The device is further provided for determining a model value (313) of the control error at the point in time on the basis of an estimated value (314, 315) of the measured offset of the phase current sensor (115) at the point in time by means of a model (302) dependent on the stator inductance of the electric machine (103). Furthermore, the device is designed to determine, by means of the filter unit (301), an estimated value (314, 315) of a measured offset of the phase current sensor (115) at the next point in time on the basis of the measured value (215) of the control error and on the basis of the model value (313) of the control error.

The invention relates to the technical field of motor manufacturing and power electronic driving control, in particular to a variable-frequency energy-saving motor and a braking system thereof, and the system comprises an integrated magnetic circuit transmission module, an impedance self-adaptive adjustment module and a high-frequency harmonic suppression module; wherein the impedance adjusting module adjusts topology according to the magnetic flux density; when the magnetic flux density is lower than a threshold value, a low-magnetic-resistance path is formed; when the voltage is higher than the threshold value, local magnetic saturation is utilized to block an original path, and magnetic flux is forced to migrate to a deep yoke part; the strategy of changing the space into the linearity effectively compensates magnetic conductivity reduction caused by material saturation, maintains the stator inductance in a linear range, solves the problem of brake failure caused by inductance collapse under high current, avoids over-current shutdown of a frequency converter, and remarkably improves the reliability of the motor under limit brake.