503 results about "Rotor flux" patented technology

An apparatus and method for determining a condition of an electric machine. Search coils are wound around stator teeth and the induced voltage is used to decouple stator and rotor fluxes. The decoupled fluxes allow for machine condition monitoring and fault diagnosis.

A variable reluctance motor and methods for control. The motor may include N motor phases, where N equals three or more. Each motor phase may include a coil to generate a magnetic flux, a stator and a rotor. A flux-carrying element for the rotor and/or stator may be made entirely of SMC. The stators and rotors of the N motor phases may be arranged relative to each other so that when the stator and rotor teeth of a selected phase are aligned, the stator and rotor teeth in each of the other motor phases are offset from each other, e.g., by an integer multiple of 1/N of a pitch of the stator or rotor teeth. A fill factor of the coil relative to the space in which it is housed may be at least 60%, and up to 90% or more. The stator and rotor flux-carrying elements together may include at most three separable parts.

The invention relates to the technical field of PMSMs, solves a coupling problem during online identification of multiple parameters of a surface-mounted type PMSM, and achieves online decoupling identification of PMSM inductance, stator resistance and rotor flux linkage. Accordingly, the technical scheme adopted by the invention is that an online decoupling identification method of multiple parameters of the PMSM comprises the steps as follows: 1) identifying and coupling analysis of parameters of the PMSM; 2) a decoupling identification strategy, wherein voltage deviation before and after D shaft current injection is used for increasing the order of a motor mathematical equation, so that the decoupling identification of multiple parameters of the surface-mounted type PMSM inductance, the stator resistance and the rotor flux linkage are achieved; 3) neural network identifier design, wherein according to a parameter online identification problem of the PMSM, online identification is performed on motor parameters by adopting a self-adaptive neural network structure and a weight convergence algorithm based on a least mean square algorithm. The method is mainly applied to the design and manufacture of the PMSM.

The invention provides a method for controlling without-position sensor vector of a doubly-fed wind generator, wherein the control method adopts closed loop algorithm on the basis of a model reference self-adaptive module to indentify the rotor position and the rotary speed of a double fed wind induction generator. The control of the without-position sensor vector is possible, the cost of a generator system is lowered, and the anti-interference ability is improved. Simultaneously, the control method also adopts a method for improving voltage module observation flux linkages to observe a stator flux linkage under a stator static coordinate and a rotor flux linkage under a rotor static coordinate, the method can solve the problems that flux linkage phases which are obtained through observing the flux linkage through adopting a high pass filtering method are advanced and the amplitude is reduced, and the flux linkage which is corresponding with true value phases and amplitude is obtained.

The invention relates to the technical field of electric transmission and control, in particular to a speed sensor-less method for estimating the rotor angle and the revolving speed of a permanent-magnet synchronous motor. The method comprises the following steps: a. obtaining the rotor flux linkage amplitude Psi<r> of a permanent-magnet synchronous motor; b. transforming a stator voltage fundamental component to be under an alpha beta coordinate system to obtain u<alpha> and u<beta>; c. transforming the stator current fundamental component to be under the alpha beta coordinate system to obtain i<alpha> and i<beta>; d. carrying out highpass filtering on stator current i<alpha> and i<beta> under the alpha beta coordinate system, and obtaining the differential estimation value sum of the stator current; e. obtaining a stator counter electromotive force estimation value; f. obtaining a rotor revolving speed calculation value omega<rC> and a rotor angle calculation value theta<rC>; g. carrying out lowpass filtering on the rotor revolving speed calculation value omega<rC> to obtain a rotor revolving speed estimation value; h. obtaining the estimation value of a rotor angle starting value; and i. obtaining a rotor angle estimation value. The method has the advantages that only forward calculation, instead of a feedback channel, exists in the method for estimating the rotor angle and revolving speed, and except filter delaying, no dynamic regulation process exists.

The invention discloses a speed sensorless vector control method on the basis of a cascaded high voltage inverter, which is characterized by comprising the following steps of: 1, establishing a rotor flux linkage voltage model; 2, establishing a rotor flux linkage current model; 3, identifying a rotating speed, using the rotor flux linkage current model in a two-phase rotating coordinate system in the step 2 as an adjustable model, using the rotor flux linkage voltage model in the step 1 as a reference model, utilizing a model reference adaptive system, and adopting a Popov hyperstability theory to obtain a rotating speed identifying model; 4, obtaining a three-phase sinusoidal voltage reference signal by speed and current double close loop control; and 5, sending the three-phase sinusoidal voltage reference signal to a phase-shifting SPWM (Sinusoidal Pulse Width Modulation) distributing plate, controlling a cascaded power unit by utilizing a phase-shifting SPWM control method and controlling the rotating speed of a motor. Due to the adoption of the method disclosed by the invention, a speed sensor does not need to be arranged on a motor shaft, the defects caused by the installation of a speed encoder are avoided, and the flux linkage and the rotating speed of the motor can be well estimated.

A generator system is configured to supply relatively constant frequency AC power when driven by a variable speed prime mover, by independently controlling the main rotor flux rotational speed. The generator system includes an exciter stator that induces current in the exciter rotor windings at a desired frequency and phasing. The exciter rotor windings are electrically connected to the main rotor windings, and are thus electrically excited at the same frequency and phasing. Excitation is supplied to the exciter stator from an exciter controller, which controls the frequency and phasing of the exciter excitation, based on the rotational speed of the generator, to maintain a constant output frequency.

Methods and systems for controlling an electric motor are provided. An estimated rotor flux angular position error is generated based on estimated back electromotive force (EMF) values, and based on the estimated rotor flux angular position error, an estimated rotor flux angular position, an estimated electrical synchronous frequency and/or an estimated rotor frequency can be generated.

The invention relates to a low-voltage traversing control method for a double-fed wind power generation system, which belongs to the technical field of wind power generation. The method comprises the following steps: firstly, the stator flux and the rotor flux of a double-fed generator are calculated according to the stator current and the rotor current of the double-fed generator which are measured by a current sensor; secondly, the stator flux is multiplied by a corresponding proportionality factor to serve as the set value of the rotor flux of the double-fed generator, so as to control therotor flux; and thirdly, the rotor flux is controlled in the way that as feedforward compensation decoupling is performed, closed-loop control is conducted to the decoupled system, and a rotor-side converter is controlled after pulse-width modulation is conducted to the obtained voltage control quantity of a rotor-side converter, so as to achieve low-voltage traversing control during failures. The low-voltage traversing control method provided by the invention has fast response, and very good traversing effect when symmetrical and asymmetrical drop failures of the network voltage occur, meanwhile, and oscillation of output electromagnetic torque of the double-fed generator can be effectively inhibited. The control method is simple and suitable for engineering application.

Motor drives, motor speed controllers, motor speed estimation systems, and methods are presented for controlling motor startup speed and for estimating motor speed during startup, in which a speed estimate controller provides a rotor speed estimate based on a first error term from a torque-based MRAS component for a first range of motor speeds and based on a second error term from a rotor flux-based MRAS component for a second range of speeds.

The invention relates to a non-speed sensor vector control method of an AC asynchronous motor, which belongs to the motor control technical field. The method comprises the following steps; firstly, an exciting current and a torque current are obtained through the rotor flux oriented synchronous rotation transformation; secondly, the torque current is utilized for calculating the slip angular frequency of the motor and estimating the rotating speed of the motor; thirdly, the synchronous angular frequency is adjusted by utilizing the commanded rotating speed and the estimated error of the motor rotating speed; and finally, the control voltage applied to the electric motor is directly calculated and obtained according to a motor model, wherein the position of a rotor flux is obtained by the synchronous angular frequency integral. The invention has the advantages of simple implementation, good portability, less calculation amount, low processer requirements, less control parameters, easy parameter selection and easy system debugging. The method has reliable stability and low system parameter robustness.

A system for operating an electric motor is described. The system has a torque estimator to determine a load on the motor and a controller configured to generate a motor control signal. The controller continuously adjusts the motor control signal in response to the load on the motor. The motor control signal optimizes the motor's performance by controlling the rotor flux of the motor. The motor control signal can control the voltage or current and frequency applied to the motor.

The invention discloses a bearing-free asynchronous motor control method based on a neural network inverse system theory. A composite controlled object is composed of two sets of Park inverse transformation, two sets of Clark inverse transformation, two sets of current regulating inverters, a flux linkage observer, and a bearing-free asynchronous motor; a fuzzy neural network and integrators form a fuzzy neural network inverse system; and the fuzzy neural network inverse system is in series connection with the composite controlled object; besides, the bearing-free asynchronous motor is decoupled into a pseudo linear system comprising two displacement subsystems, a rotating speed subsystem and a rotor flux linkage subsystem; and the obtained pseudo linear system is introduced into internal model control to form closed-loop control. According to the invention, the control precision is high and there is high robustness on an external disturbance, a parameter change and a modeling error, thereby realizing high-performance control on a bearing-free asynchronous motor.

A method of correcting the determination of extended rotor flux using a lag function and a correction algorithm that closely approximates a pure integrator function to correct for lag function errors that can extend the EFS control down to dynamoelectric machine speeds corresponding to as low as 10 Hz electrical frequency.

The invention relates to an observation method and device for an electromagnetic torque of a salient pole type permanent-magnet brushless direct current motor, and is particularly suitable for the electromagnetic torque and rotation speed control of a motor driving system without position sensors or speed sensors. The observation method and the observation device utilize a rotor counter electromotive force self-adapting stator current observation device, a phase-locked loop based rotor rotation speed and position angle observation device, a rotor counter electromotive force/rotor flux/rotor position angle relation curve, a coordinate conversion device, a stator flux computing device and an electromagnetic torque computing device to observe the electromagnetic torque continuously, instantly and accurately when the position sensors are not available, and observe rotor speed and stator flux in an intermediate variable manner simultaneously, so that the sensorless, high-performance and direct-torque control requirements of the motor are met. The observation method and the device have the advantages of good instantaneity, high observation accuracy, low cost and the like.

The invention discloses a method for asynchronous motor rotor flux linkage observation and rotation speed identification, which comprises the following steps of: according to stator voltage and current signals measured in real time, observing to obtain a rotor flux linkage through a sliding mode observer based on a super-twisting theory and using the rotor flux linkage as a reference value; using a rotor flux linkage calculated according to a rotor flux linkage current model as an adjustable value; constructing a model reference self-adaptive system (MRAS) based on the rotor flux linkages; and identifying the asynchronous motor rotation speed through the self-adaptive law. The rotation speed identification method provided by the invention has high robustness for the variation of stator resistance, and can provide accurate rotor flux linkages and rotation speed values, thereby being especially suitable for an asynchronous motor vector control system.

A generator system is configured to supply two phase excitation current from an exciter rotor to a main generator rotor. When driven by a variable speed prime mover, the generator system provides relatively constant frequency AC power by independently controlling the main rotor flux rotational speed. The generator system includes an exciter stator that induces current in the exciter rotor windings at a desired frequency and phasing. The exciter rotor windings are electrically connected to the main rotor windings to provide two-phase excitation current to the main rotor windings. Excitation is supplied to the exciter stator from an exciter controller, which controls the frequency and phasing of the exciter excitation, based on the rotational speed of the generator, to maintain a constant output frequency. The exciter frequency control function of the exciter controller may be eliminated when the generator system is driven by a constant speed prime mover or when a narrow band variable frequency output is required.

The invention relates to a method for the controlled application of a stator-current target value (I_Snom) and a torque target value (M_nom) for a polyphase machine (4) that is supplied by an electronic power converter. According to the invention: current components (I_Sdnom, I_Sqnom) in a co-ordinate system (d, q) with a fixed rotor flux or rotating magnetic pole are calculated in accordance with a torque target value and in asynchronous machines in accordance with a rotor-flux target value (Ψ_Rnom), a calculated rotor-flux actual value (Ψ<SB>R</SB>) or a rotating magnetic-pole flux; a stator-circuit frequency (ω<SB>S</SB>) is determined; a terminal-flux target value (Ψ_Knom) is calculated in accordance with the values (I_Snom, I_Sqnom, Ψ<SB>R</SB>, ω<SB>S</SB>) by means of the machine parameters (L, R<SB>S</SB>), said terminal-flux target value being subsequently projected onto a flux-course curve, selected from stored, off-line optimised flux-course curves. This permits the state of the stator current (I<SB>S</SB>) to be regulated in relation to the rotor flux (Ψ<SB>R</SB>) or rotating magnetic-pole flux by means of momentary values, facilitating a stationary and dynamic precise control of motor currents (I₁,I₂,I₃) and thus the torques (M) of a polyphase machine (4).

A system (10) for controlling the torque of an induction motor (12) utilizes a flux observer (14). The flux observer (14) receives stator current inputs (16, 18) and a rotor speed estimate (80) and then outputs a rotor flux estimate (20) that provides increased motor control stability at all speeds.

The invention discloses a control method and system of a permanent magnet synchronous motor. The control method comprises the steps that stator flux linkage of the permanent magnet synchronous motor and stator flux linkage deviation are worked out by the adoption of a voltage model and a current model; stator flux linkage of the synchronous motor and rotor flux linkage of the synchronous motor under a dp coordinate system are worked out by the utilization of a conversion matrix between a two-phase static coordinate system and a two-phase synchronous rotating coordinate system; finally, the rotor position angle and the rotor angular speed of the permanent synchronous motor are worked out through the closed loop phase lock technology of rotor q-axis flux linkage. The control method and system of the permanent magnet synchronous motor have the advantages that on the basis of a non-sensor estimation method of a flux linkage closed loop phase-locked loop of the rotor flux linkage of the permanent magnet synchronous motor and by the adoption of the technology of conducting compensation on the stator flux linkage deviation through the voltage model and the current model, the accuracy of the estimation algorithm is improved and effective control over the permanent magnet synchronous motor in the full-speed range can be realized.

A shaft sensorless rotor angular position and velocity sensing system for a dynamoelectric machine that is based on dynamoelectric machine extended flux estimation.