Patent application number | Description | Published |
20090009119 | POWER CONVERTING DEVICE FOR ELECTRIC TRAIN - A power converting device for an electric train includes a power converter, an alternating-current motor, a primary control unit, and a control unit. The power converter converts direct-current power into alternating-current power. The alternating-current motor is driven by the alternating-current power output from the power converter. The primary control unit outputs a power-running notch command that determines an acceleration speed for the electric train. The control unit controls an amount of the alternating-current power based on the power-running notch command. The control unit sets the amount of the alternating-current power to zero without a delay after receiving an OFF signal of the power-running notch command during power running. | 01-08-2009 |
20090167236 | Control Apparatus for AC Rotary Machine and Control Method for AC Rotary Machine - A control apparatus for an AC rotary machine, comprising a VVVF inverter | 07-02-2009 |
20090251082 | CONTROLLER FOR AC ROTARY MACHINE - A controller for an AC rotary machine is proposed, by which a stable rotation angular-frequency estimate value can be obtained even in an extremely low speed region of the AC rotary machine, and consequently stable control can be performed. A controller for an AC rotary machine has an angular-frequency estimate output means | 10-08-2009 |
20090251083 | Control Apparatus for AC Rotary Machine - A control controls starting of an AC rotary machine by calculating a resistance drop component, corresponding to a resistance drop of the AC rotary machine, based on a detection current, and adjusts angular frequency of an AC output voltage based on subtracting the resistance drop component from a voltage command, and, simultaneously, adjusting amplitude of the AC output voltage so that amplitude of an AC phase current may change in conformity with a predetermined function. | 10-08-2009 |
20100033996 | POWER CONVERTING APPARATUS - A detected DC voltage value estimation mechanism samples detected DC voltage values at specific intervals of a period T, stores detected DC voltage values V | 02-11-2010 |
20100060212 | Control Apparatus for Electric Railcar - A control apparatus for an electric railcar includes an inverter that exchanges power with an AC rotating machine, a filter capacitor connected in parallel to a DC side of the inverter, a filter reactor provided between the filter capacitor and an overhead line, an overhead line voltage measuring instrument that measures a voltage value of the overhead line, a voltage increase detection unit that senses an amount of voltage increase occurring when, with an overhead line voltage being supplied, the overhead line voltage goes beyond a reference voltage value and rises at a rate equal to or higher than that by a predetermined time constant. A correction torque command value calculation unit calculates a correction torque command value that is corrected so that a torque command value to be received from an external unit becomes smaller for a predetermined time elapsing after the voltage increase detection unit has sensed, during regeneration operation of the inverter, an amount of voltage increase more than a predetermined range. A vector control unit controls the inverter so that the AC rotating machine develops torque coincident with the correction torque command value. | 03-11-2010 |
20100118569 | POWER CONVERSION SYSTEM - A power conversion system includes a first power converter converting AC to DC, a second power converter converting DC to AC, a current detector detecting output current of the second power converter, a pulsation detector detecting a pulsating component associated with the AC to DC conversion of the first power converter from a pulsating component contained in at least any one of effective power, power, and apparent power of the second power converter, a voltage corrector outputting a correction amount correcting at least one of phase, frequency, and amplitude of a voltage output from the second power converter based on the pulsating component from the pulsation detector, and a voltage controller outputting a voltage instruction to be output from the second power converter based on the correction amount from the voltage corrector, wherein the second power converter converts DC to AC based on the voltage instruction from the voltage controller. | 05-13-2010 |
20100128502 | ELECTRIC POWER CONVERSION APPARATUS - A power converter includes: a converter ( | 05-27-2010 |
20100191399 | WHEEL DIAMETER MEASURING APPARATUS OF ELECTRIC VEHICLE - A wheel diameter measuring apparatus for measuring a wheel diameter of an electric vehicle of speed sensorless vector control to which a synchronous motor is applied is obtained. | 07-29-2010 |
20100194322 | ELECTRIC VEHICLE CONTROLLER - An electric vehicle controller includes a speed sensorless vector controller for estimating the rotating speed of an AC motor from an output voltage command and an output current from a VVVF inverter, and controlling the VVVF inverter based on the estimate. An overhead wire current detector detects the current flowing through an overhead wire. A wrong action sensor senses an abnormality in the speed sensorless vector controller from the sign of the current flowing through the overhead wire and detected by the overhead wire current detector when the VVVF inverter is in operation. A gate stop circuit stops the VVVF inverter when the wrong action sensor senses an abnormality. | 08-05-2010 |
20100308649 | ELECTRICAL POWER CONVERSION APPARATUS - In a conventional electrical power conversion apparatus, a control microprocessor performs a control for eliminating or curbing a beat phenomenon, so that a control delay occurs because computing time is required in the control microprocessor. Because of the control delay, it is not possible to obtain an effect of sufficiently reducing a current ripple and torque pulsation. In addition, in an electric train in which a frequency of an AC power source is changed over while the train is running, it is required for a method of detecting a ripple component by a band-pass filter that a plurality of band-pass filters are provided and then the changeover is performed depending on the power source frequency, resulting in difficulties to take countermeasures. An electrical power conversion apparatus according to the present invention stores DC voltage values at predetermined sampling time-points going back from the latest, and predicts a DC voltage estimate value for a predetermined elapse time from the latest sampling time-point using the stored DC voltage values, whereby using the predicted DC voltage estimate value, an amplitude and/or a frequency of AC power that an inverter outputs is controlled so as to curb variation of the AC power that the inverter outputs, due to a ripple caused on the DC side of the inverter. | 12-09-2010 |
20110140642 | POWER CONVERSION DEVICE - Based on rotation information of a synchronous machine detected by a rotation information detector, a controller causes a converter to boost a charge voltage of a capacitor so as to be higher than an induced voltage generated by the synchronous machine at a time of shifting to a coasting operation, maintains the charge voltage during the coasting operation, and performs weak field control so that the induced voltage generated by the synchronous machine becomes lower than a DC voltage at the time of shifting from the coasting operation to a power running operation or to a regenerative operation. | 06-16-2011 |
20110194318 | ELECTRICAL POWER CONVERSION APPARATUS - An electrical conversion apparatus including a converter and an inverter comprises a capacitor that stores a DC electrical power; a ripple detection unit that detects a ripple of an RMS power that is generated from the inverter; a voltage measuring instrument that measures a voltage across the capacitor; a DC voltage command generation unit that calculates a command value of the voltage across the capacitor according to a frequency of the AC voltage generated from the inverter; and a DC voltage control unit that receives the voltage measured by the voltage measuring instrument and the command value calculated by the DC voltage command generation unit, to control the converter so that the voltage across the capacitor becomes the command value, wherein the DC voltage command generation unit makes the command value of the voltage across the capacitor higher than usual, in situations where the voltage across the capacitor is within a predetermined range including a frequency of a ripple component of the voltage across the capacitor. | 08-11-2011 |
20120001587 | POWER CONVERTING APPARATUS - A power converting apparatus including a power converter that converts a DC voltage into an AC voltage and applies the AC voltage to an AC rotating machine and a control unit that controls the power converter based on an operation command from the outside is provided. The power converting apparatus includes: a first calculating unit that calculates and outputs, from a d-axis current detection value and a q-axis current detection value detected by the AC rotating machine and current command values based on the operation command, first voltage command values to the power converter, magnetic fluxes of the AC rotating machine, and an angular frequency; and a second calculating unit that sets, as an initial value, at least one of the magnetic fluxes and the angular frequency input from the first calculating unit and calculates and outputs second voltage command value to the power converter and an angular frequency. | 01-05-2012 |
20120019178 | POWER CONVERSION APPARATUS AND METHOD OF CONTROLLING CAPACITOR VOLTAGE OF POWER CONVERSION APPARATUS - A power conversion apparatus includes: a line breaker that is connected in series to a direct-current power supply; a first capacitor that is connected in parallel to the direct-current power supply through the line breaker; a discharge circuit that includes a resistor and a first switching circuit connected in series and is connected in parallel to the first capacitor; a power converter for driving a synchronous machine; a second capacitor that is connected in parallel to a direct-current side of the power converter; a second switching circuit that is connected in series between the first capacitor and the second capacitor; and a control circuit for controlling the discharge circuit. The control circuit controls the discharge circuit on the basis of the voltage of the first capacitor and the voltage of the second capacitor. | 01-26-2012 |
20120181961 | POWER CONVERTING APPARATUS FOR ELECTRIC VEHICLE - A controller that controls ON/OFF of switching elements and opening/closing of an opening/closing unit based on currents detected by current detectors. The controller includes a fault detector that detects whether any of the switching elements has a short-circuit fault and outputs a signal indicating a detection result, an ON/OFF controller that sets one of the switching elements that constitutes a phase other than a first phase that involves the short-circuit fault to an ON operation state and outputs a signal for opening the opening/closing unit, and an opening/closing controller that opens an opening/closing unit connected to a third phase other than the first phase and the second phase in which one of the switching elements is set to the ON operation state by the ON/OFF controller. | 07-19-2012 |
20120212163 | POWER CONVERSION APPARATUS OF ELECTRIC VEHICLE - A power conversion apparatus of an electric vehicle includes: a power converter for driving an induction machine based on arbitrary d- and q-axis voltage commands Vd* and Vq*, and a control unit for controlling the power converter based on a power running command P and a brake command B from outside. The control unit includes: a dq/three-phase conversion unit for converting phase current information iu, iv, and iw detected from the induction machine into d- and q-axis current detection values id and iq on orthogonal rotating coordinates; a speed determination unit for computing d- and q-axis voltage commands Vd* and Vq* for the power converter and determines that speed of the induction machine is zero based on the power running command P, the brake command B, and the B- and q-axis current detection values id and iq; and a resistance computing unit for computing a resistance value of the induction machine based on the power running command P, the d-axis current detection value id, and the d-axis voltage command Vd* when the brake command B is changed to the power running command P and the speed determination unit determines that the speed of the induction machine is zero. | 08-23-2012 |
20130043812 | POWER CONVERSION DEVICE - A power conversion device includes a first capacitor connected in parallel to a direct-current power supply, plural power converters that drive plural synchronous machines, a second capacitor connected in parallel to a direct-current side of power converters, a switching circuit inserted between the first and second capacitors, a switch-start instruction unit that controls starting of an operation of the power converters, and a control unit that controls the power converters based on a motor velocity and a voltage of the first capacitor. The switch-start instruction unit turns off the switching circuit while the power converters stop, turns off the switching circuit until a terminal voltage of each of the synchronous machines becomes equal to a predetermined value when each of the power converters starts operating, and turns on the switching circuit when the terminal voltage of each synchronous machine becomes equal to or smaller than the predetermined value. | 02-21-2013 |
20130073252 | MAGNETIC-POLE POSITION DETECTION APPARATUS FOR SYNCHRONOUS MACHINES - An object is to provide a magnetic-pole position detection apparatus for synchronous machines that allows a desired accuracy of magnetic-pole position detection regardless of variation in DC voltage of a DC voltage source. Calculation means ( | 03-21-2013 |
20130113399 | CONTROL APPARATUS AND CONTROL METHOD FOR AC ROTARY MACHINE - A control apparatus for an AC rotary machine includes a control circuit, a power converter, a current detector, and a voltage detector. The control circuit includes: an activation current instruction unit which generates a current instruction for activation; and a start phase setting unit which sets an initial rotation phase for activation control, based on the rotation direction of the AC rotary machine just after activation and on the polarity of current detected by the current detector just after activation. Thus, the current amplitude and torque shock just after activation control is started can be reduced, and assured and stable reactivation is allowed without causing the protection operation. | 05-09-2013 |