Lg Electronics Inc.

Electronics, Inc.

Dal Ho Cheong

Jae Yoon Oh

June Hee Won

Kyung Hoon Lee

Gil Su Lee

Dong Myung Lee

Soon Bae Yang

Kyung Hun Lee

Hyun Hun Shin

A PMA (Permanent Magnet Assisted) synRM and a method for imposing a magnetic force thereon. Magnets are inserted into outer flux barriers of a plurality of flux barriers formed along the radius of a rotor, and bridges or slim portions are formed on inner flux barriers at positions corresponding to the positions of the magnets so that the magnetic force is imposed on the magnets through coils. Since the number of the flux barriers is sufficiently increased while the amount of the magnets consumed is decreased, the PMA synRM has increased efficiency and reduced production costs.

Permanent magnet assisted synRM and method for imposing magnetic force thereon

An apparatus and method determine a start-up of a sensorless motor. The apparatus includes an elapsed time determination unit, a motor velocity determination unit and an abnormal start-up determination unit. The elapsed time determination unit determines whether a predetermined time has elapsed after a start-up of the motor is initiated. The motor velocity determination unit determines whether a velocity of the motor exceeds a predetermined velocity value when the predetermined time has elapsed. The abnormal start-up determination unit determines that the motor was abnormally started up when the velocity of the motor does not exceed the predetermined value, and an amount of current flowing in the motor does not exceed a predetermined current value.

Apparatus and method for determining normal start up of sensorless motor

A sensorless motor drive apparatus and a method for protecting and controlling the same. The sensorless motor drive apparatus includes a unit for determining the presence or absence of a position estimation error of a rotor contained in a motor using a current value applied to the motor and a position estimation angle of the rotor. Therefore, the sensorless motor drive apparatus determines the presence or absence of the position estimation error of the rotor without using a sensor, so that it reduces production costs, prevents the motor from generating a faulty operation, and prevents a compressor including the motor from being damaged.

Sensorless motor drive apparatus and method for protecting and controlling the same

Disclosed are a flux observer and a sensorless control system of a synchronous reluctance motor. The flux observer includes an estimated flux output unit, a measured flux output unit, and a fixed/rotational coordinate converter. The flux observer estimates a flux of a synchronous reluctance motor by removing higher harmonic components of a current in a rotational coordinate system which flows into the motor. The measured flux output unit measures a flux in a fixed coordinate system by combining a voltage in the fixed coordinate system, which is applied to the motor, and a current in the fixed coordinate system, from which higher harmonic components are removed, with the estimated flux outputted from the estimated flux output unit. The fixed/rotational coordinate converter converts the measured flux outputted from the measured flux output unit to a measured flux in the rotational coordinate system.

Apparatus for measuring magnetic flux of synchronous reluctance motor and sensorless control system for the same motor

A rotor for a synchronous reluctance motor of flux barrier type and manufacturing method thereof constructs a rotor for a synchronous reluctance motor by forming a magnetic core steel plate of disc shape on which a shaft hole is formed at center part, and a plurality of flux barrier groups are formed centering around the shaft hole and automatic stacking points are formed; manufacturing a plate stacked body by stacking the core steel plates continuously using the automatic stacking points; disposing end plates on both sides of the plate stacked body; and coupling the end plates and the plate stacked body integrally with each other as inserting a coupling member into the flux barrier groups, whereby the manufacturing process can be made easy and automatic stacking of the core steel plates can be made regardless of the types such as a skew type or a non skew type, and therefore manufacturing cost is reduced and the rotor can be mass produced.

Method of manufacturing a rotor for a synchronous reluctance motor

The present invention relates to a system and a method for controlling a motor. A rotation/fixed coordinates converter converts a reference magnetic flux voltage and a reference torque voltage of a rotation coordinates system into data of a fixed coordinates system, and outputs the data to the three-phase voltage generator. A fixed/rotation coordinates converter converts a three-phase current applied from the inverter to the motor into a two-phase current. An estimation unit estimates a rotation angle and rotor speed of the motor upon receiving currents applied to the fixed/rotation coordinates converter. A control block receives the estimated rotation angle and the estimated speed from the estimation unit, and outputs the reference magnetic flux voltage and the reference torque voltage of the motor to the rotation/fixed coordinates converter to compensate an error caused by loads generated when driving the motor. Thus, the control system greatly reduces noise and vibrations of a compressor without being affected by loads generated by compression/expansion strokes of the compressor at a startup time of the motor, and prevents a performance of the compressor from being deteriorated.

System for controlling motor and method for the same

An apparatus for controlling the rotation speed of a motor, which is capable of controlling the rotation speed and the torque of the motor by detecting the input voltage and the input current of the motor without using a sensor for detecting the position of the rotor of the motor, is provided. The apparatus for controlling the rotation speed of a motor includes a synchronous/stationary coordinate converter for comparing the reference speed of a motor with the estimated speed of the motor and outputting reference magnetic flux component current and reference torque component current for compensating for an error value according to the comparison result as the reference voltage of an &agr; axis and the reference voltage of a &bgr; axis in a stationary coordinate system, a two phase current generator for receiving three phase current detected when the motor rotates and outputting magnetic flux component current and torque component current, a speed/position estimation operator for estimating the position and the rotation speed of a rotor in the motor on the basis of the reference of the &agr; axis, the reference voltage of the &bgr; axis, the current of the &agr; axis, the current of the &bgr; axis, and reference speed and controlling the rotation speed and the torque of the motor.

Apparatus for controlling rotation speed of motor

Disclosed are a phase distortion compensating apparatus and method for reducing a torque ripple in a 3-phase motor using four switching elements, which are capable of adjusting respective switching times of phase voltages, to be supplied to the 3-phase motor by an inverter including the switching elements, based on a voltage difference between upper and lower DC link capacitors respectively adapted to supply voltages to the inverter, thereby reducing a torque ripple generated in the motor. The apparatus includes a rectifier unit, upper and lower DC link capacitors connected in parallel to the rectifier unit, each of the capacitors serving to conduct charge and discharge operations for a DC voltage outputted from the rectifier unit, an inverter connected in parallel to the capacitors and adapted to generate a 3-phase voltage adapted to rotate the motor, based on voltages respectively discharged from the capacitors along with a switching signal, and a voltage command generator for calculating compensation components for respective switching operations of switching elements of A and B phases included in the inverter, based on a voltage difference between the capacitors, a difference between an actual motor speed and a command speed, and a rotor position, and providing respective switching times including the calculated compensation components, thereby controlling a rotating speed of the motor.

Phase distortion compensating apparatus and method for reducing torque ripple in 3-phase motor

Disclosed are a voltage compensating apparatus and method for a 3-phase inverter using four switches, to compensate for a severe distortion of a 3-phase application voltage due to a voltage ripple. The voltage compensating apparatus includes upper and lower DC link capacitors connected to each other in series and adapted to receive an input DC voltage, and to charge the DC voltage therein, a B inverter supplying a voltage to a 3-phase motor , using the four switches, when it receives the charged voltage from each of the DC link capacitors, a diodebridge receiving an AC voltage from an AC voltage source, rectifying the received AC voltage into a DC voltage, and applying the rectified DC voltage to the upper and lower DC link capacitors as the input DC voltage, and a triac coupled at an input terminal thereof to one line of the AC voltage source while being coupled at an output terminal thereof to a connection node between the upper and lower DC link capacitors, the triac serving to control whether or not the upper and lower DC link capacitors are to be charged with the DC voltage, respectively. In accordance with the present invention, the upper and lower DC link capacitors are charged through different paths, respectively. Accordingly, a control for DC link voltages is enabled to achieve a reduction in voltage ripple while minimizing a degradation in performance.

Growing community of inventors

Seoul, South Korea

Dal Ho Cheong