Patent application number | Description | Published |
20120268046 | CONTROL DEVICE FOR ALTERNATING CURRENT MOTOR - A control device for an alternating current motor according to embodiments includes a current distributor and a phase estimator. The current distributor divides a torque command by using a control phase and outputs a component that contributes to a mechanical output of the motor as a δ-axis current command and a component that does not contribute to the mechanical output as a γ-axis current command. The phase estimator computes a phase at which a γ-axis component of an addition amount of the output of the current controller and a voltage drop amount of inductance of the motor becomes zero and outputs the computed phase as the control phase. | 10-25-2012 |
20140125261 | CONTROLLER OF AC MOTOR - A controller of an AC motor includes a d-axis voltage command section to generate a d-axis voltage command on a d axis of a d-q coordinate system. A d-axis non-interactive control section removes, from the d-axis voltage command, an interference component resulting from a current on a q axis of the system. A first current deviation arithmetic section obtains a deviation between a current command on the q axis and the current on the q axis flowing through the AC motor. A q-axis integral control section outputs an integral value of the deviation. A q-axis voltage command section generates a q-axis voltage command based on the deviation. A constant output control section outputs a correction voltage command based on the integral value. A d-axis voltage command correction section subtracts the correction voltage command from the d-axis voltage command after non-interactive control to correct the d-axis voltage command. | 05-08-2014 |
20150115906 | MATRIX CONVERTER - A matrix converter includes: a power converter configured to couple an AC power supply and a load together; and a controller configured to selectively execute: a first control mode in which the controller is configured to perform power conversion between the AC power supply and the load; and a second control mode in which the controller is configured to directly combine the AC power supply with the load. The controller is configured to: increase the output voltage and cause a phase of the output voltage follow up a voltage phase of the AC power supply in a case where a difference between a frequency of an output voltage from the power converter to the load and a frequency of the AC power supply becomes within a predetermined range. | 04-30-2015 |
20150130431 | MATRIX CONVERTER AND METHOD FOR COMPENSATING FOR OUTPUT VOLTAGE ERROR - A matrix converter includes a power converter, a command generator, and a commutation controller. The power converter includes bidirectional switches each having a conducting direction controllable by switching elements. The bidirectional switches are disposed between input terminals coupled to phases of an AC power source and output terminals coupled to phases of a load. The command generator generates a control command based on a voltage command specifying a pulse width of pulse width modulation control. The commutation controller controls the switching elements by a commutation method based on the control command so as to perform commutation control. The command generator includes a corrector to, when an error in an output voltage is caused by the commutation control, correct the pulse width specified in the voltage command in generating the control command to reduce the error in the output voltage. | 05-14-2015 |
20150130432 | MATRIX CONVERTER AND METHOD FOR COMPENSATING FOR OUTPUT VOLTAGE ERROR - A matrix converter includes a power converter, a control information generator, a commutation controller, a storage, and an error compensator. The power converter includes bidirectional switches each having a conducting direction controllable by switching elements. The bidirectional switches are disposed between input terminals and output terminals. The input terminals are respectively coupled to phases of an AC power source. The output terminals are respectively coupled to phases of a load. The control information generator generates control information to control the bidirectional switches. The commutation controller controls each of the switching elements based on the control information so as to perform commutation control. The storage stores setting information of at least one of a method of the commutation control and a modulation method of power conversion. The error compensator compensates for an output voltage error based on the setting information. | 05-14-2015 |
20160036364 | MOTOR CONTROL DEVICE, AND METHOD AND DEVICE FOR ESTIMATING MAGNETIC FLUX OF ELECTRIC MOTOR - A motor control device is provided, which includes a power converter for applying output voltage according to a voltage command to an electric motor, a magnetic flux estimator for estimating a vector of stator magnetic flux of the electric motor based on a difference between the output voltage and a voltage drop caused by a coil resistance of the electric motor, and a phase estimator for estimating a phase of the stator magnetic flux based on the vector of the stator magnetic flux estimated by the magnetic flux estimator. The magnetic flux estimator includes a variable low-pass filter for applying a low-pass filter to the difference at a cut-off frequency according to a frequency of the output voltage, and a phase adjuster for retarding at least one of an output phase of the variable low-pass filter and a phase of the difference before inputted into the variable low-pass filter. | 02-04-2016 |
20160094139 | MATRIX CONVERTOR, POWER GENERATION SYSTEM, AND METHOD FOR CONVERTING POWER - A matrix convertor includes a power convertor, a commutation controller, an error compensator, and a compensation amount adjustor. The power convertor is disposed between input phases and output phases. The power convertor includes a plurality of bidirectional switches each including a plurality of switching elements. The commutation controller is configured to perform commutation control with respect to the plurality of switching elements of each of the plurality of bidirectional switches using a commutation pattern including a plurality of steps so as to switch connection between the input phases and the output phases through the power convertor. The error compensator is configured to calculate a compensation amount to decrease an error in an output voltage caused by the commutation control. The compensation amount adjustor is configured to decrease the compensation amount based on at least one voltage among voltages of the output phases. | 03-31-2016 |
20160094140 | MATRIX CONVERTOR, POWER GENERATION SYSTEM, AND METHOD FOR CONVERTING POWER - A matrix convertor includes a power convertor and a controller. The power convertor includes a plurality of bidirectional switches disposed between a plurality of input phases and a plurality of output phases. The controller is configured to generate a control command and control the power convertor based on the control command. The control command includes a switching pattern that causes a first input phase among the input phases to be connected to one output phase among the output phases and that causes connection of the input phases to be switched between a rest of the output phases. In generating the control command, the controller is configured to set a lower limit to a period of time during which a second input phase among the input phases that corresponds to an intermediate voltage is connected to the rest of the output phases. | 03-31-2016 |