Abstract: 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 a

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A controller for an AC rotary machine, by which a stable rotation angular-frequency estimate (AFE) value can be obtained even in an extremely low speed region of the AC rotary machine is disclosed, and consequently stable control can be performed. The controller includes an AFE outputter that outputs an AFE value based on an angular-frequency calculated value including a rotation AFE value. The AFE outputter includes a lower-limit constant-value (LLCV) outputter that outputs a LLCV, a comparator that compares the angular-frequency calculated value to the LLCV, and a switcher that performs a switching operation according to the comparator. The switcher outputs the angular-frequency calculation value as the AFE value when the angular-frequency calculation value is larger than the LLCV, and outputs the LLCV as the AFE value when the angular-frequency calculation value is equal to or less than the LLCV.

Abstract: A control apparatus for an electric car, including a power converter which feeds AC power of variable voltage and variable frequency to a primary side member of a linear electromagnetic actuator, voltage command means for giving a command of a voltage which is fed to the linear electromagnetic actuator, current detection means for detecting current information which flows between the power converter and the linear electromagnetic actuator, and motor constant calculation means for calculating a motor constant of the linear electromagnetic actuator on the basis of the voltage information Vu given by the voltage command means and the current information Iu detected by the current detection means.

Abstract: 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.

Abstract: To propose a control apparatus for an electric train, in which the regenerative energy of a DC power feed circuit can be consumed without disposing the brake chopper or electric-double-layer capacitor of the DC power feed circuit. A control apparatus for an electric train according to this invention includes an AC electric motor which drives the electric train, and a variable-voltage variable-frequency inverter which controls the AC electric motor, and further includes an auxiliary power source device connected to a DC power feed circuit, and load control means for controlling a load connected to the auxiliary power source device, wherein the load control means receives an inverter state signal representative of an operation state of the variable-voltage variable-frequency inverter from the it, and the load control means controls the load in accordance with the inverter state signal.

Abstract: 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.

Abstract: 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. A wheel diameter measuring apparatus of an electric vehicle comprising a synchronous motor driven by an electric power converter for converting a DC voltage into an AC voltage comprises a voltage detector for detecting an AC voltage generated by a magnetic field of the synchronous motor during coasting of the electric vehicle in which the electric power converter stops, and a calculation part for calculating a wheel diameter of a wheel driven by the synchronous motor from an AC voltage detected by the voltage detector and speed information about the electric vehicle.

Abstract: [Problem] To propose a control apparatus for an electric train, in which the regenerative energy of a DC power feed circuit can be consumed without disposing the brake chopper or electric-double-layer capacitor of the DC power feed circuit. [Means] A control apparatus for an electric train according to this invention includes an AC electric motor which drives the electric train, and a variable-voltage variable-frequency inverter which controls the AC electric motor, and further includes an auxiliary power source device connected to a DC power feed circuit, and load control means for controlling a load connected to the auxiliary power source device, wherein the load control means receives an inverter state signal representative of an operation state of the variable-voltage variable-frequency inverter from the it, and the load control means controls the load in accordance with the inverter state signal.

Abstract: A power converter includes: a converter (1) which rectifies an AC power; capacitor series assemblies (2A, 2B) connected to the DC side of the converter; an inverter (3) which assumes that one end of the capacitor series assemblies is at a high potential, the other end is at a low potential, and a series connection point is at an intermediate potential and selects one of the high potential, the intermediate potential, and the low potential for output of a 3-phase AC; an inverter control unit (4) which controls the inverter (3); and a voltage measuring device (8) which measures a capacitor voltage Vdc as a voltage between the both ends of the capacitor series assemblies (2A, 2B). The inverter control unit (4) has a beatless control unit (21) which controls the modulation ratio ? in accordance with a capacitor voltage Vdc and a frequency fixation unit (22) which fixes the frequency of the AC voltage outputted by the inverter (3) to an instruction value.

Abstract: 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.

Abstract: 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.

Abstract: A detected DC voltage value estimation mechanism samples detected DC voltage values at specific intervals of a period T, stores detected DC voltage values Vn to Vn?m detected at a present time tn up to a sampling time tn?m which is m sampling cycles (m?1) before the present time tn, and calculates a DC voltage estimation value Vn+1 at a next time tn+1 using the detected DC voltage values Vn to Vn,m, expressing a curve connecting the voltage values Vn to Vn?m by a specific function. An output voltage control into which the DC voltage estimation value Vn+1 is input corrects an output voltage command value and outputs the corrected output voltage command value to a power converter.

Abstract: 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 20 that outputs an angular-frequency estimate value ?i based on an angular-frequency calculated value ?1 including a rotation angular-frequency estimate value ?e.

Abstract: 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.

Abstract: A control apparatus for an AC rotary machine, comprising a VVVF inverter 1 which exchanges electric power between it and the AC rotary machine, a voltage detector 16 which detects voltage information of a DC side of the inverter 1, current detectors 3 which detect current information items of an AC side of the inverter 1, an inverter-electric-power command unit 20 which determines an inverter-electric-power command value in accordance with the detected voltage information, an actual-inverter-electric-power calculation unit 19 which calculates an actual inverter-electric-power value on the basis of the detected current information items, a secondary-magnetic-flux command calculation unit 18 which calculates a secondary-magnetic-flux command value for the AC rotary machine, on the basis of a difference between the inverter-electric-power command value and the actual inverter-electric-power value, a-predetermined-secondary-magnetic-flux command unit 23 which outputs a predetermined secondary-magnetic-flux comman

Abstract: 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.

Abstract: This invention provides a base station radio apparatus, a mobile unit communication system, and a control method for a base station radio apparatus that suppress a deterioration in communication quality. Success rates can be monitored by monitoring outgoing/incoming calls and call connections, and control can be executed to detect a potential card for which a success rate declines and force the card to enter an ALM state. Thus, a deterioration in communication quality can be suppressed.