2461 results about "Synchronous motor" patented technology

A rotary sensor that outputs two analog signals, such as one sine wave and one cosine wave and has multiple periods within one period of the electrical angle of a motor is employed. The motor is energized at each position for a specified length of time upon its startup by using multiple electrical angles corresponding to the multiple candidate absolute angles obtained from the rotary sensor signal as the initial position of the motor, and the electrical angle at which the motor acceleration becomes maximum is determined as the absolute angle. While the motor drive is in operation, on the other hand, the phase difference Δθ between the phase of the motor at the counter electromotive voltage and the control phase is directly computed from the parameters of the motor, sensed current, voltage command and angle speed so as to correct the shifted position. A high-efficiency motor drive unit with improved maintainability of rotary sensor and improved accuracy of sensing the magnet pole position of a permanent magnet synchronous motor that accelerates and decelerates very quickly in a wide range of speed is realized.

Aspects of the invention provide a transport system powered by short block Linear Synchronous Motors (LSMs). The use of short blocks allows vehicles to move under precise control even when they are in close proximity to each other. The design allows the vehicles to be propelled and guided while negotiating sharp turns and negotiating merge and diverge switches. A coreless LSM can be used to create propulsive force without attractive force so as to allow a relatively high drag vehicle suspension, such as a vehicle sliding on a smooth surface. Further aspects of the invention provide a switching member that is selectively moveable relative to a guideway in order to change a magnetic force acting on the vehicle transverse to a direction of motion of the vehicle.

Aspects of the invention provide a transport system powered by short block Linear Synchronous Motors (LSMs). The use of short blocks allows vehicles to move under precise control even when they are in close proximity to each other. The design allows the vehicles to be propelled and guided while negotiating sharp turns and negotiating merge and diverge switches. A coreless LSM can be used to create propulsive force without attractive force so as to allow a relatively high drag vehicle suspension, such as a vehicle sliding on a smooth surface.

The experience of a consumer of a primary video or audio program is enriched by providing secondary and time relevant content to a secondary device, such as a laptop computer, tablet, or smart phone. Transmissions of the primary video or audio are augmented by secondary data providing links to the secondary content. The secondary data also contains data identifying the corresponding primary program and the temporal location within the primary program at which the secondary content is to be offered. Upon receipt and display of a pre-produced primary program, a device driving the primary program output device, such as a set-top-box driving a television, transmits the secondary data over a local network to the secondary device, which displays links to the secondary data, and enables the consumer to request the corresponding secondary content for display on the secondary device. Indications of secondary content may also be sent to the primary program output device to inform the consumer of the availability of secondary content.

A synchronous motor drive system in accordance with the present invention detects a DC current of an inverter which drives a synchronous motor, and based on the magnitude of the current, estimates torque current components that flow through the motor, and then based on the estimated value, determines the voltage which is applied to the motor, and finally estimates and computes the magnetic pole axis located inside the motor using the estimated value of the torque current.

Specific anomalies and details of failures as well as measures thereagainst are described that might possibly occur in electric power converters that drive and control permanent-magnet synchronous motors. An electric power converter capable of stable operation has a protective function of taking proper measures against such failures that might possibly occur.

The invention discloses a method and a device for controlling speed of a permanent-magnet synchronous motor. The method includes that an active-disturbance-rejection control technology is adopted for a speed ring, speed setting and a speed detection value are taken as input of a first-order active-disturbance-rejection controller, a tracking differentiator reasonably arranges a transition process, an extended state observer observes an actual value of rotating speed of the motor, estimates total disturbance of a system and acquires output of the speed ring through a nonlinear state error feedback control ratio, a load torque observer is designed through detection values of a current and the speed, and observed load torque through output of a feedforward controller and the active-disturbance-rejection controller is taken as reference input of a quadrature-axis current. The method carries forward characteristics of overshoot freeness, high disturbance rejection capacity, good robustness and the like of the permanent-magnet synchronous motor in speed control in the active-disturbance-rejection control technology, and compensation is performed on the problem of load disturbance, so that the problem of fluctuation of the rotating speed under the circumstance of load disturbance is improved.

Disclosed is a high-speed control method for a permanent magnet synchronous motor-compressor system, including the following steps: initial design is carried out; a motor is detected through DSP, including detecting the two-phase current of the stator of the motor, the voltage Udc of a DC generatrix; the voltage of a d-p shaft is calculated; faults of overcurrent, overpressure and undervoltage are detected; if any fault exists, the PWM pulse signals are blocked and then the control program is paused; if no fault exists, the following steps will be carried out; the rotating speed of the motor and the position of the rotor are identified in the process of speed-position estimation; the current and the voltage of the reference d-q shaft of the motor are calculated; switching signals of an inverter are acquired through haplotype over-modulation; the data are recorded and waveforms are displayed; judgment of whether to pause the control program is carried out; if not, the second step is carried out again; if yes, the control program will be paused. The control method applies haplotype over-modulation method into the permanent magnet synchronous motor-compressor system, realizing sensorless over-modulation to the synchronous motor-compressor vector control system.

A driving apparatus of a synchronous motor fixes all the switching devices of an inverter at OFF in accordance with a value of an all-OFF control pulse signal outputted by a pulse generator. A motor current keeps flowing through free wheel diodes for a predetermined period even after all the switching devices shift to the OFF state. Therefore, pulse generator changes an induced voltage detection signal to an H (high) level after the passage of the time in which a motor current drops down to zero. A terminal voltage of the motor is taken in to acquire an induced voltage and a rotor position is estimated.

A position detecting device which can increase accuracy in detecting the pole position of a motor used to perform quick acceleration and deceleration over the range from a zero speed to a high rotation speed, and a synchronous motor driving device using the position detecting device. A position detector detects basic-wave component signals in sensor signals and executes position calculation. A correcting unit calculates signal information representing at least one of a gain, an offset and a phase by a phase detector from the basic-wave component signals detected by an error calculator, and makes correction based on the calculated signal information such that a position detection error is zero.

In a synchronous motor control device that corrects a deviation in rotational position which is related to a rotational position detector for a synchronous motor on which vector-control is performed, the synchronous motor control device includes: a current instruction generator that disables a torque instruction to set d-axis and q-axis current instructions as zero when a phase correction instruction is inputted; a current controller that outputs d-axis and q-axis voltage instructions based on the d-axis and q-axis current instructions; a phase correction quantity detector for determining the amount of offset in which the d-axis voltage instruction becomes zero when the phase correction instruction is inputted and the d-axis voltage instruction is not zero; an adder for adding a rotor positional angle and the amount of offset; and a voltage converter for determining three-phase voltage instructions based on the additional value, the d-axis and q-axis voltage instructions.

Advantageous motors, such as flux-switching linear synchronous motors (FSLSMs) are provided. In an FSLSM, all magnets can be magnetized in the same direction. In addition, an FSLSM can be yokeless and can have two stators displaced from one another by half a pole pitch. FSLSMs of the subject invention are cost-effective and provide high thrust, and can operate well even under fault conditions.

The present invention aims to provide a synchronous motor drive system that is capable of suppressing ripples in current while reducing switching loss. The system includes three-phase inverters 201-203, a control circuit 400 for controlling the operations of the three-phase inverters and a synchronous motor 300 including a plurality of three-phase coils. To control the operations of the three-phase inverters, the control circuit 400 causes the three-phase inverters 201 and 203 and the three-phase inverter 202 to use different carrier frequencies to generate three-phase AC power, and each of the three-phase inverters supplies a different one of the three-phase coils with three-phase AC power.

The invention provides a method for detecting the initial position of a magnetic pole of a rotor of a built-in permanent magnetic synchronous motor, belongs to the field of motor control, and solves the problems of over-complicated processing, easy occurrence of polarity misjudging, poor practicality and the like existing in the conventional method based on high-frequency signal injection for detecting the initial position of the rotor. The method comprises the following steps: constantly maintaining the stationary state of the rotor; injecting a rotating high-frequency voltage signal into a stator winding; detecting three-phase stator current and converting the three-phase stator current into two-phase static coordinates; acquiring an error signal capable of reflecting position information of the magnetic pole of the rotor through signal processing; adjusting the error signal by using a PI tracker so as to acquire an initial judging value of the position of the magnetic pole of the rotor; and injecting two impulse voltage vectors in opposite directions into the stator winding, comparing values of direct axis current components by detecting the three phase current and converting the rotating coordinates so as to determine the polarity of the magnetic pole, and finally acquiring the initial position angle of the magnetic pole of the rotor of the built-in permanent magnetic synchronous motor.

A system for transmitting real-time data between an asynchronous network (104) and a synchronous network (106) is disclosed. A method (100) may include an ingress path (102) for transmitting data from an asynchronous system (104) to a synchronous system (106), and an egress path (108) for transmitting data from a synchronous system (106) to an asynchronous system (104). An ingress path (102) may include a packet receiver (110) and write to synchronous system (112) steps. An egress path (108) may include read from synchronous system (114), packetizer (116), and packet transmitter (118) steps.

A drive system of a permanent magnet motor is constituted of a mode switching trigger generator which monitors a state of a permanent magnet motor and issues a mode switching trigger, a conduction mode determining unit which receives the mode switching trigger and switches the mode of the permanent magnet motor, and a PWM generator which outputs a PWM signal to an inverter in accordance with the output of the conduction mode determining unit. The mode switching trigger is generated on condition that the speed electromotive force of the permanent magnet motor exceeds a constant or variable threshold value.

The invention provides a motor control device, a motor control system, a motor control module and a refrigerating unit, capable of reducing switching shock when switching from synchrony operation mode to non-position sensor mode. In a control device 6a comprising a dc vector control device for controlling rotating speed of permanent magnet synchronous motor consistent with speed instruction value omega i through an inverter, comprising a synchrony operation mode for driving the permanent magnet synchronous motor together with a rotating angle theta m' obtained by integraling the speed instruction value; and a non-position sensor mode for proceeding feedback control to rotating angle theta m of the permanent synchronous motor, comprising a switcher 19 that speculating shaft error (delta theta c) of the stator shaft of the permanent magnet synchronous motor and control system shaft of the dq vector control part, and when the speculated shaft error almost consistent with phase difference of current instruction value, the synchronous rotating mode is switched into the non-position sensor mode.

The invention relates to a method for recognizing parameters of asynchronous motor. The stator resistance of motor is measured by a method of DC volt-ampere. The rotor resistances as well as leakage inductance of stator and rotor of motor is obtained by short circuit test. Mutual inductance of stator and rotor of motor can be taken from method of no-load test. Compensating voltage drop in on state, switch time delay and dead time raises the accuracy and stability of recognized parameter. The resistance values of rotor at frequency of rating sliding difference are calculated by method of two points through test of locked rotor at two frequencies. Since skin effect is overcome, the resistance values of rotor are accurate enough so as to meet the requirement of vector control system completely.

An adaptive, sensorless position sensing apparatus (250) derives rotor position of a synchronous machine (200). The apparatus (250) comprises a first rotor position deriving unit (300) for generating first rotor position values by applying a first sensorless rotor position calculation technique, which emulates a resolver; a second rotor position deriving unit (400) for generating second rotor position values by applying a second sensorless rotor position calculation technique; and a rotor position result output unit (450) for outputting rotor position results over a range of rotor speeds as a function of the first rotor position values, the second rotor position values, and rotor speed.

The invention discloses a digit control machine double-shaft synchronization control device, comprising a clock, an input and output interface, a double-shaft position check module, a control unit, a system parameter list and a pitch compensation list, wherein the double-shaft position check module processes position and synchronization error check for two synchronous shaft motor encoders and provides the check information to the control unit, the control unit selects a working mode corresponding to the parameters of the system parameter list, according to the position and error information of the two synchronous shafts provided with the double-shaft position check module and the process corresponding to the selected working mode, the control on the two synchronous shafts can be realized. The invention resolves the problem of the common digit control system which can not realize synchronous control, realizes the real-time character between transfer and adjustment, avoids the profile error of processed elements caused by delayed transfer time, and avoids the serious dynamic synchronous error caused by long adjustment.

In order to provide a driving device for a motor having a capability equivalent to conventional vector control type sensorless method by simplifying the controls structure to reduce number of parts to be adjusted, and to stabilize the control system, a driving device for a synchronous motor does not include a speed controller or a current controller, and calculates a voltage impressed on a motor on coordinate axes (dc/qc axes) based on a magnetic pole axis. For calculating a voltage command, command values such as a rotation speed command and a current command are used, and Iq* corresponding to a torque current command is calculated and provided based on a detected current value.

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 inductance parameter identification method of a synchronous motor and an implementation system thereof are provided. The method comprises: applying a three-phase balance high frequency voltage or current signal to the synchronous motor; sampling a feedback high frequency current or voltage of the synchronous motor; extracting positive sequence and negative sequence component amplitude of the feedback high frequency current or voltage which has the same frequency of the injecting voltage or current; and calculating to get d-axis inductance Ld and q-axis inductance Lq of the synchronous motor. Identification of the d-axis inductance and q-axis inductance of the synchronous motor can be implemented more accurately on a general inverter on the basis of non-increase of hardware cost. The method and system have the following advantages of implementing easily, not high demand for the motor feedback current sampling accuracy, and controlling easily for the frequency and amplitude of the high frequency voltage signal injected into the motor, and identifying to get the d-axis inductance and q-axis inductance of the motor directly no matter the motor shaft is in a free state, or in a hold tight stage, which do not affect accuracy of identification.

This invention discloses a system and method to operate a doubly-fed induction generator (DFIG) as a grid-friendly virtual synchronous generator (VSG). It comprises a DFIG modeled as a virtual differential gear that links a rotor shaft driven by a prime mover, a virtual stator shaft coupled with a virtual synchronous generator G and a virtual slip shaft coupled with a virtual synchronous motor M, and a variable frequency drive that behaves as a virtual synchronous motor-generator set to regulate the speed of the virtual synchronous motor M so that the speed of the virtual stator shaft, i.e., the speed of the virtual synchronous generator G, is within a narrow band around the grid frequency even when the rotor shah: speed changes. As a result, a grid-connected DFIG can be controlled to behave like a virtual synchronous generator without using a PLL.

A synchronous motor controlling apparatus which can be applied to the carrier synchronized position estimating method as well and have protection-related functions such as detection of inverted magnetic pole position of a motor in a simple method, and an electric motor using the synchronous motor control apparatus. A controller controls a voltage applied to an AC motor with a PWM signal. A magnetic pole position detector of the controller detects a current of the AC motor to estimate a pole position of the AC motor. A fault detector detects a fault in the estimated magnetic position of the AC motor.

A compressor assembly for use in transporting natural gas is provided. The assembly includes a natural gas compressor comprising at least one stage of compression, a permanent magnet-type super-synchronous motor coupled to the natural gas compressor for powering said compressor, and a housing, the compressor positioned within the housing, and the compressor configured to facilitate increasing a pressure of natural gas being transmitted.

A position sensorless drive method capable of driving a permanent magnet motor by an ideal sine-wave current and enabling the driving from an extremely low-speed range in the vicinity of zero-speed is provided. A neutral-point potential of the permanent magnet motor is detected in synchronization with a PWM waveform of an inverter. The position of a rotor of the permanent magnet motor is estimated from the variation of the neutral-point potential. Since the neutral-point potential is varied in accordance with the magnetic circuit characteristics of an individual permanent magnet motor, the position can be detected regardless of the presence of saliency of the permanent magnet motor.

A synchronous motor with low vibrations and an electric driving system using the motor. A field-coil synchronous motor comprises a stator and a rotor rotatably supported at the inner peripheral side of the stator with a gap left relative to the stator. The stator has a stator coil supplied with electric power while being controlled such that driving torque is reduced as a rotation speed of the rotor increases, and the rotor has a field coil supplied with a field current while being controlled such that the field current is reduced as the rotation speed of the rotor increases. The rotor is a tandem claw-pole rotor comprising plural pairs of N- and S-claw poles disposed side by side in an axial direction, and the plural pairs of claw poles of said tandem claw-pole rotor are relatively shifted from each other in a circumferential direction.

The invention relates to a brushless doubly-fed motor excitation control system, which is characterized by comprising a PWM (Pulse-Width Modulation) rectifying unit, a first current sensor, a smoothing reactor, a contactor, an excitation controller and an inverter unit, an operation and display unit, an energy storage device, a BOOST reactor, a soft start circuit, a first voltage detection circuit and a second voltage detection circuit. The brushless doubly-fed motor excitation control system can always keep a speed-variable load-variable constant-frequency and constant-voltage power generation state when a brushless doubly-fed motor is at an electric operating state, the rotating speed of a brushless rotor rapidly changes and the load condition is within a larger range; and when the brushless doubly-fed motor is at the electric operating state, the brushless doubly-fed motor excitation control system can finish rapid adjustment of the rotating speed of the brushless rotor by excitation control and realizes multiple electric operating modes, such as synchronous operating, asynchronous operating and doubly-fed speed adjustment. When the load condition changes in a larger range, the brushless doubly-fed motor excitation control system can always keep the hard mechanical property of a synchronous motor. The invention also comprises the control method using the brushless doubly-fed motor excitation control system.