Kabushiki Kaisha Toshiba

Tokyo Shibaura Denki Kabushiki Kaisha

Susumu Tadakuma

Shigeru Tanaka

Kazuo Shimane

A power conversion system including a single-phase AC power source for generating an AC power. The power conversion system further includes an AC/DC power converter connected to the single-phase AC power source for converting the AC power into a DC power, a main smoothing capacitor connected to DC terminals of the AC/DC power converter, a DC active filter connected in parallel with the main smoothing capacitor for controlling a compensation current flowing in the DC active filter such as to absorb an amount of fluctuation of the AC power supplied from the single-phase AC power source, and a load device connected to the main smoothing capacitor as a DC voltage source for receiving a first DC voltage applied to the main smoothing capacitor.

Power conversion system

A slip frequency type driving control apparatus includes a detector for detecting an input current and an input voltage to an induction motor, a calculating unit for calculating a rotor flux and a torque current of the induction motor, a neural network for outputting an excitation current command value and a slip frequency command value, and a vector control unit for performing vector control for the induction motor. The neural network receives a rotor flux command value, a torque current command value, a calculated rotor flux value, and a calculated torque current value, performs learning on the basis of a back-propagation law using signals output in correspondence with these inputs, and outputs an excitation current command value and a slip frequency command value. The vector control unit detects the torque current and the excitation current on the basis of the output slip frequency command value from the neural network and controls the induction motor in accordance with a deviation between the detected excitation current value and the excitation current command value and a deviation between the detected torque current value and the torque current command value.

Driving control apparatus for induction motor

A slip frequency type vector control apparatus for an induction machine which is provided with first and second feedback circuits for correcting respective magnetization current command and torque current command supplied feed-forwardly so as to eliminate the influence of a change in temperature of the induction machine secondary resistance and realize a correct vector control.

Control apparatus for induction machine

An AC motor drive apparatus of this invention is constituted by an AC power source, a first circulating current type cycloconverter having an output terminal coupled to the AC power source, a phase-advanced capacitor coupled to an input terminal of the first cycloconverter, a second circulating current type cycloconverter having an input terminal coupled to the phase-advanced capacitor, and an AC motor coupled to an output terminal of the second cycloconverter. The first cycloconverter controls a current supplied from the AC power source to be a sine wave in the same phase as that of the power source voltage, so that a voltage crest value of the phase-advanced capacitor becomes substantially constant. The second cycloconverter supplies a sine wave current of a variable frequency to the AC motor.

AC motor drive apparatus

A power control apparatus which includes a cycloconverter having thyristors in which a circulating current flows, for supplying a compensating current to AC power lines; capacitors for supplying a reactive current component of the compensating current to the thyristors; a trigger control circuit for controlling the triggering of the thyristors; a detector coupled to the cycloconverter, for detecting from switching currents flowing through the thyristors a circulating signal corresponding to the circulating current. The compensating current serves to improve the power factor of the AC lines as well as to reduce higher harmonic currents on the AC lines. The circulating signal is fed back to the trigger control circuit so that the amount of the circulating current is kept substantially constant according to a negative feedback operation.

Reactive power compensating cycloconverter

A circulating current of a cycloconverter in each phase is distributed and controlled in such a way that a circulating current in a phase having a large absolute value of a load current is small, and the circulating current of a phase having a small absolute value of the load current is large. Therefore, the reactive power is so compensated that the sum of lagged reactive powers of the phases and advanced reactive power of a phase advancing capacitor cancel out each other.

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Atsugi, Japan

Susumu Tadakuma