570 results about "Rotor angle" patented technology

A new method for predicting the rotor angle stability status of a power system immediately after a large disturbance is presented. The proposed two stage method involves estimation of the similarity of post-fault voltage trajectories of the generator buses after the disturbance to some pre-identified templates and then prediction of the stability status using a classifier which takes the similarity values calculated at the different generator buses as inputs. The typical bus voltage variation patterns after a disturbance for both stable and unstable situations are identified from a database of simulations using fuzzy C-means clustering algorithm. The same database is used to train a support vector machine classifier which takes proximity of the actual voltage variations to the identified templates as features.

This invention provides an advanced position and velocity estimation scheme used in a position-sensorless control system for synchronous operation of an electric motor. The system includes an electric motor having a stator and a rotor; an inverter for powering the electric motor; and a controller for controlling the inverter. The controller utilizes a control system comprising a rotor angle and angular velocity estimation block; an estimated angle error detector block; a field-weakening block; and a torque-to-current converter block, all of which operate to generate control commands for operation of the motor.

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.

An apparatus and method for determining the angular position of a rotor. The rotor is a part of a resolver used to determine the position of a shaft, or the like, in operation in a system such as a shaft in a missile gimbal. A digital signal processor is used advantageously to reduce cost. The inherently poorer performance of a data sampling approach in the presence of noise, as compared to the prior art tracking converter approach, is overcome by novel application of the digital signal processor and related circuitry.

The invention provides a method for detecting rotor position of a switch reluctance motor without a position sensor, and belongs to the field of motor control. The invention aims at solving the problems existing in the prior method for indirectly detecting the rotor position that resisting moment and moment harmonic components occur in the motor rotor so that the efficiency of a motor system is reduced. The method comprises the following steps: 1, winding current i and busbar voltage U are sampled; and 2, according to the winding current in step one, instantaneous inductance (L) of the winding is acquired, and by looking up the winding instantaneous inductance (L) and rotor angle relation table, the rotor position is acquired. The method can lower manufacturing process of the switch reluctance motor, and has good application prospect in oil fields, coal mines, elevators, home appliances and the like.

To a neutral point of a motor is connected a positive electrode of an auxiliary battery and an auxiliary load. Voltage on a power supply line to the auxiliary load, a neutral point voltage, is detected, and disconnection of the auxiliary battery is determined when an increase of ripples in the neutral point voltage is detected. When a voltmeter cannot be used, control of the neutral point voltage is continued by measuring current of the auxiliary battery and performing control such that the current value becomes 0. A resolver is further provided on the motor for detecting the rotor angle with high accuracy. A control circuit generates, in accordance with an output of the resolver, a voltage control signal for each phase current having the same amplitude as the carrier amplitude during startup, and compares the voltage control signal to carrier to obtain a gate signal having the same frequency as the carrier frequency. In switching of the inverter, due to this gate signal, periods in which all phases are on or off are reduced, thereby preventing a large neutral point current.

The invention provides an automatic surfacing device of an inner wall anticorrosion layer of a 90-degree bent pipe and an automatic surfacing method thereof, belonging to the technical field of automatic surfacing and solving the technical problems of long surfacing period and hardly guaranteed surfacing quality of the inner wall anticorrosion layer of a 90-degree bent pipe in a heavy type pressure vessel in the background art. In the automatic surfacing device and the automatic surfacing method, the rotor angle and the displacement of a welding gun head (12-1) is completed through the rotation of a rotary angle motor (12-3) and the displacement of a three-dimensional guide rail (14), the rotation of an overturn motor (5) enables the 90-degree bent pipe to rotate, the swinging of a swinging motor (8) enables the welding gun head (12-1) to carry out surfacing at a certain speed, accordingly, the previous factors enable the inner wall of the 90-degree bent pipe to realize high-efficiency and high-quality surfacing. The invention is mainly used for the surfacing of the inner wall of the 90-degree bent pipe in the heavy type pressure vessel with the working environment of high temperature, high pressure and corrosion medium contacting.

A system for measuring speed of a high-speed motor using a moving average filter. A position sensor generates a rotor position signal. A signal processing module determines a rotor angle from the rotor position signal. A speed observer module calculates a raw speed of the motor from the rotor angle. A filter module selectively generates a filtered speed of the motor from the raw speed of the motor. A frequency-to-period converter module calculates a rotor period from one of the raw speed of the motor and the filtered speed of the motor. A divider module calculates number of points in a moving average from the rotor period. A moving average filter module adjusts a window size of the moving average to the rotor period. A moving average filter removes ripple and harmonics of the ripple from the raw speed of the motor.

The invention relates to fault loss estimation of a power network and provides a practical and effective fault loss estimation method for the risk assessment of transient rotor angle stability. In the technical scheme adopted by the invention, the fault loss estimation method for the risk assessment of the transient rotor angle stability comprises the following steps of: performing the ordinary power flow calculation to obtain the initial condition; performing transient time domain simulation and calculating trace sensitivity; if instability is determined, resolving a transient stability minimum control cost model; and if the convergence conditions that the absolute value of delta PL is less than epsilon and that the absolute value of delta Pg is less than epsilon are not met, repeating the previous steps. The method is mainly applied to the fault loss estimation and management of the power network.

A method of conducting smooth motor startup is provided and includes operating a motor in an open loop control scheme at startup, operating the motor in a closed loop sensorless control scheme at a time after startup and transitioning between the open loop control scheme and the closed loop control scheme by reducing a difference between an estimated rotor angle of the motor and a commanded ramping angle of the motor.

By utilizing a mechanical backlash generated between an electric actuator and a shift range switching mechanism, a specific region is obtained, in which a variation in the output shaft angle is relatively small with respect to a variation in rotor angle. In this specific range, an actual shift range position is calculated, whereby the rotor angle that the motor controller recognizes is corrected so as to relate the actual shift range position. A deviation between the rotor angle and the actual shift range is corrected, so that the shift range switching is precisely performed.

The invention provides a method for on-line fault diagnosis and fault-tolerant control of position signals of a switch reluctance motor. A position sensor detects the rotation position of a three-phase 12/8 pole rotor in real time, the relative position of the rotor of the motor is determined according to a built-up sequence of three paths of feedback position signals and a trigger edge, then a position angle q of the rotor is calculated, and by combination with a current energizing phase, fault position signals and fault types can be diagnosed in an on-line mode; under the fault state, invalid phase changing actions are rebuilt, correct phase changing operations are conducted, fault tolerance and recovery control over the position signals are conducted, the continuous operation of the motor after the fault is achieved, and the correct cut-in of the position signals when the fault recovery is performed is achieved. The method is convenient to achieve and reliable in operation, in the diagnosis process, the rotor position angle q is amended in each rotor angle cycle, an accumulative error can not be produced, and the accumulative influence on the output performance of a system does not exist; the method can diagnose the fault position signals and the fault types in the on-line mode and enable the system to rapidly recover normal stable operation, and the reliability of the system is improved.

In a vehicle steering system, when a sensor malfunction determination unit detects a malfunction of a rotation angle sensor, the sensor malfunction determination unit changes a control mode from a first control mode to a second control mode. In the second control mode, an actual rotor angle (mechanical angle) (θ_SM) of a steered system motor is computed on the basis of a second rotor angle (electric angle) (θ_SE2) estimated by a rotation angle estimation unit. Then, feedback control is executed such that the actual rotor angle (θ_SM) converges to a target rotor angle (θ_SM1*) that is obtained by superimposing a rotation maintaining command signal on a target rotor angle (θ_SM*) computed by a target rotor angle computation unit.

An apparatus and method for estimating rotor angle information for the control of permanent magnet AC motors having sinusoidal current excitation. The disclosed motor drive can provide full load operation at very low speeds including zero speed without the use of a shaft position sensing device. The rotor angle is estimated through injection of high frequency current, and rotor angle is extracted by a signal-conditioning algorithm, which utilizes current amplitude differential to discriminate the rotor angle. Rotor angle magnetic axis orientation (North or South pole) at startup is detected by comparing time average current ripple (at signal injection frequency) content between two different levels of d-axis current injection.

The present disclosure relates to a method for determining the position of a rotor of a polyphase motor, e.g., the rotor angle, particularly at standstill. The method can include: applying voltage to phases of the motor, measuring a current in the phases, and determining the rotor position based on the measured current. According to the present disclosure, determination of the rotor position can be based on current values measured during a period where zero voltage is applied to the respective phases.

The invention discloses a motor rotor position detection method and device and belongs to the technical field of driving control. The method is used for a motor control main chip and comprises the steps of: receiving output signals of a rotary transformer, wherein the output signals are excited by excitation signals output by the motor control main chip and comprise sine analog signals and cosine analog signals; determining a target rotor angle of the rotary transformer according to the output signals of the rotary transformer; determining a motor rotor angle according to the target rotor angle of the rotary transformer; and detecting the position of the motor rotor according to the motor rotor angle. The motor rotor position detection method and device solve the problem in the prior art that the cost is relatively high when the rotary transformer is utilized to detect the position of the permanent magnet synchronous motor rotor, the cost of permanent magnet synchronous motor rotor position detection is lowered, and the motor rotor position detection method and device can be used to detect the position of the permanent magnet synchronous motor rotor.

The invention relates to a motor rotor position detection method, and specifically relates to position detection of a rotor of a permanent magnet synchronous motor. The method comprises the steps of installing three Hall elements at positions spacing from each other by 120-degree electrical angle of a stator side of the permanent magnet synchronous motor so as to acquire Hall signals, after Hall detection signals are obtained, on the one hand, determining which area the rotor is in according to a correspondence relationship of the Hall signal and the rotor angle, on the other hand, calculatinga rotor rotating speed through a T method; estimating the rotor angle according to the obtained area in which the rotor is and the rotor rotating speed; and correcting the rotor angle by using an angle slow correction method so as to determine the position of the rotor. In the method, the Hall elements are used to detect the position of the rotor, so that the method has the advantages of being low-cost, easy and convenient; a clock division value of a timer is corrected in real time, so that the optimal resolution is guaranteed; and the rotor angle is corrected by using the angle slow correction method, so that current fluctuation is reduced effectively, and the motor runs stably.