| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 318729000 | Power-factor control | 15 |
| 20090085510 | Motor Drive Using Flux Adjustment to Control Power Factor - The switching rectifier and switching inverter on a motor drive unit are modulated to indirectly change the magnitude of current and voltage stored in DC link by controlling the magnetic field of the motor to correct for both power factor lead and power factor lag over a wide range of motor speeds and conditions while maintaining a predetermined motor operating point. | 04-02-2009 |
| 20090212733 | To Obtain the Three-Phase Current via adjusting width of pulses with Single DC-Link Current Sensor - After an AC motor generates a three-phase current, modulate the three-phase current to generate an original voltage space vector, and add three detecting vectors with a sum of zero after the original voltage space vector. While adding the three detecting vectors, sample the current to generate a sampling result. Then adjust the width of pulses generated by a pulse width modulator according to the sampling result. | 08-27-2009 |
| 20100283423 | ELECTRIC MOTOR CONTROL ALGORITHM WITH BYPASS RELAY - Aspects of the present invention pertain to a method of power control for an electrical motor using a control bypass feature that allows for the delivery of full supply voltage to a motor when it is operating at or above a certain load threshold level. Advantages of the present invention include the ability to provide power savings at low loads while still a motor to operate at full rated capacity under high load conditions. Also, a load sensor and an override unit that are independent of the phase lag compensation portion of power control allows for faster response to rapid load changes. | 11-11-2010 |
| 20100327798 | APPLYING A CONTROL UNIT TO AN ASYNCHRONOUS MACHINE WHICH IS OPERATED WITHOUT A ROTARY ENCODER - Exemplary embodiments provide a method for connection or application of a converter to a rotating asynchronous machine which is operated without an encoder, without a high current and without a torque surge. The method provides a control unit, using an inverter or converter, for feeding the asynchronous machine which rotates at a mechanical rotary speed. The asynchronous machine is regulated by the control unit. A stator current vector is ascertained from measured currents of the stator windings of the asynchronous machine and a rotating stator voltage vector. Calculation is effected in respect of a stator flux change vector from the stator current vector, the stator voltage vector and a stator resistance in accordance with a motor model. An angle difference between the stator current vector and the stator flux change vector is calculated. That angle difference is regulated to a reference value of 90° or −90°, wherein an output signal of the regulator corresponds to a rotary field frequency, to be impressed, of the voltage vector of the stator. Regulation is effected in respect of an amplitude of the stator voltage vector by way of a current regulator to which the difference of a current reference value and a parameter corresponding to the amplitude of the stator current is made available at the input as a regulating difference. | 12-30-2010 |
| 20110057601 | CURRENT INJECTION CIRCUIT FOR DELAYING THE FULL OPERATION OF A POWER FACTOR CONTROL CIRCUIT FOR AC INDUCTION MOTORS - An energy saver delay circuit for an induction motor is disclosed. The energy saver delay circuit includes a power factor control circuit including an integrator, the integrator having a negative summing junction and a current injection circuit electrically connected to the negative summing junction, the current injection circuit configured for injecting an offset current into the negative summing junction to cause about the maximum available voltage from a power source to be supplied to the motor for a predetermined amount of time. Current injection may be triggered by voltage being applied to the motor, wherein the voltage exceeds a predetermined value. Alternatively, current injection may be triggered by current flowing through the motor, responsive to the current exceeding a predetermined threshold current. Alternatively, current injection may be triggered by voltage across the power factor control circuit, responsive to the voltage exceeding a predetermined threshold voltage. | 03-10-2011 |
| 20110121774 | ALTERNATING VOLTAGE CONTROL APPARATUS - The alternating voltage control apparatus which is inserted serially between an alternating-current power source and an inductive load and which controls adjustment of load voltage of the inductive load with a magnetic energy recovery switch reduces a voltage burden of a reverse conduction type semiconductor switch within the magnetic energy recovery switch and a capacitor and controls voltage to be supplied to the inductive load with a small advancing amount of a phase of current to be supplied to the inductive load. | 05-26-2011 |
| 20120019188 | INDUCTION MOTOR CONTROL DEVICE AND INDUCTION MOTOR GROUP CONTROL SYSTEM - In an induction motor group control system, magnetic energy recovery switches ( | 01-26-2012 |
| 20120086382 | MOTOR CONTROLLER AND RELATED METHOD - The present invention relates to a motor controller and related method. The invention is particularly well suited for use with an alternating current (AC) induction motor. Previously motor controllers did not take into account the combined effect a control circuit and controlled motor, had upon a mains supply and more particularly their separate and combined effect upon the power factor of an alternating current. The invention solves this problem by providing a motor controller which modifies an input current to an alternating current (AC) motor. The motor controller comprises: a power input rectifier; a low voltage power supply; a variable output voltage circuit for adjusting a drive output voltage circuit; and a control circuit arranged to control the variable output voltage circuit and to provide timed waveforms to the drive output voltage circuit. | 04-12-2012 |
| 20130063070 | MEDIUM VOLTAGE VARIABLE FREQUENCY DRIVING SYSTEM - The present invention provides a medium voltage variable frequency driving system, including a three-phase switch-mode rectification module, a multilevel inverter and a high-capacity capacitor module. The three-phase switch-mode rectification module is coupled with a three-phase electrical grid, for converting an AC voltage input with a fixed operating frequency on the three-phase electrical grid into a DC voltage. The multilevel inverter is used for converting the DC voltage into an AC voltage with a required variable frequency, so as to drive an induction motor. The high-capacity capacitor module is coupled between the three-phase switch-mode rectification module and the multilevel inverter, for temporarily storing the DC voltage. In the present invention, a three-phase switch-mode rectification technology is used at the front-end rectifier, and a diode-clamped three-level inverter is adapted correspondingly at the rear-end inverter. | 03-14-2013 |
| 20130076293 | MID-VOLTAGE VARIABLE-FREQUENCY DRIVING SYSTEM AND TOTAL HARMONIC DISTORTION COMPENSATION CONTROL METHOD - A mid-voltage variable-frequency driving system and a total harmonic distortion compensation control method are provided in this invention. The mid-voltage variable-frequency driving system includes a total harmonic distortion compensation unit. The total harmonic distortion compensation unit is used to perform an optimal adjustment on a reactive component reference value of a grid-side phase current, such that a harmonic component of the grid-side phase current may be reduced and a power factor of a three-phase switch-mode rectifier module within the mid-voltage variable-frequency driving system may be maintained. | 03-28-2013 |
| 20130088183 | Single Phase Motor Energy Economizer for Regulating the Use of Electricity - A device for improving efficiency of an induction motor soft-starts the motor by applying a power to the motor that is substantially less than the rated power of the motor then gradually increasing the power while monitoring changes in current drawn by the motor, thereby detecting when maximum efficiency is found. Once maximum efficiency is found, the nominal motor current is found and operating ranges are set. Now, the phase angle between the voltage and the current to the motor is measured and power to the motor is increasing when the phase angle is less than a minimum phase angle (determined during soft-start) and power to the motor is decreased when the phase angle is greater than or equal to the minimum phase angle as long as the voltage does not fall below a minimum voltage determined during soft-start. | 04-11-2013 |
| 20140167673 | POWER SAVING DRIVING CIRCUIT INCLUDING POWER FACTOR CORRECTION FOR AN INDUCTION MOTOR - A power saving driving circuit for a motor including power factor correction comprises an induction motor; a power factor correction capacitor; a first switching element allowing the motor to operate in a positive sine wave period of an power supply voltage; a diode allowing the power factor correction capacitor to be charged during the first switching element being OFF; a second switching element allowing the motor to operate in a negative sine wave period of the power supply voltage; another diode allowing the power factor capacitor to be charged during the second switching element being OFF; a third switching element connected in parallel to the diode; a fourth switching element connected in parallel to the other diode; and a controller controlling the motor to save power by controlling the third and fourth switching elements when a charged voltage in the power factor correction capacitor reaches a predetermined set value. | 06-19-2014 |
| 20140340019 | INVERTER AND METHOD OF CONTROLLING SAME - An inverter is provided. The inverter includes a current providing unit providing a first axis current and a second axis current to an induction motor; a revolutions per minute (RPM) measuring unit measuring the RPM of the induction motor; and a control unit changing the second axis current according to the measured RPM. | 11-20-2014 |
| 20150042260 | ELECTRICAL SOLUTION FOR SAVING POWER AND EXPENSES - An energy-saving device utilizing starting, running and power factor capacitors to operate at least one induction motor where the required input energy is significantly less than the generated output current. The capacitor configuration encourages the addition of more induction motors, whereby even as its electrical output increases, the necessary input current decreases dramatically. Such a device can save up to 90% of the energy requirements, while yielding an ever increasing amount of electrical output. The device is disclosed, along with methods of using it, and a method and device for automatically adjusting the device to either maximum energy savings or maximum energy output. | 02-12-2015 |
| 20150145466 | DOUBLE WOUND ROTOR TYPE MOTOR WITH CONSTANT ALTERNATING CURRENT OR DIRECT CURRENT POWER SUPPLY INPUT AND CONTROL METHOD THEREOF - A double wound rotor type motor with a constant alternating current or direct current power supply input and a control method thereof is disclosed. The wound rotor type motor includes: a stator in which a coil directly connected to a single phase grid power supply or a direct current power supply is wound; a rotor that is rotatably supported in the stator; a power conversion device that is attached to the rotor and controls a rotor current without connection of a separate external power supply; and a control circuit that is connected to the power conversion device and controls the power conversion device. | 05-28-2015 |
