Kabushiki Kaisha Toshiba

Tokyo Shibaura Denki Kabushiki Kaisha

Kihei Nakajima

Hiroshi Uchino

Shinji Sato

Ryoichi Kurosawa

Nagataka Seki

Kiyoshi Ogawa

Hiroyuki Nishikawa

Kenji Kijima

Kenichi Otsuka

Shoichi Irokawa

Mounting structure for capacitors

A power converter includes first and second power conversion units that are connected to each other by a d.c. reactor. The first power conversion unit is a converter in which arms consisting of thyristors are connected in a bridge configuration. The second power conversion unit is an inverter in which arms each of a series combination of a thyristor and a self-excited switch unit having a GTO for producing a commutation voltage for the thyristor are connected in a bridge configuration.

Power converter having first and second power conversion units with

In an apparatus for carrying out PWM control of an inverter having a filter connected to the a.c. output side thereof, pulse patterns adapted for determining switching timings for canceling a specified harmonic component, e.g., the fifth order harmonic component included in a voltage on the output side of the filter without exerting an influence on the output voltage fundamental wave, are stored in advance into a memory with respect to various vector quantities of the specified harmonic component to select, from a plurality of pulse patterns stored in the memory, each time a pulse pattern for reducing the specified harmonic component. The inverter is subjected to PWM control in accordance with the pulse pattern thus selected.

Harmonics suppression control circuit for a PWM inverter

In a system interconnecting inverter apparatus, an inverter for controlling power of an AC power system is coupled, via a coupling reactor, to the AC power system having a system voltage. A system phase signal indicating the phase of the system voltage is detected by a system phase detection circuit in real time. Another phase signal indicating the phase of the system voltage is detected by a comparison phase detection circuit with a predetermined delay time, and the detection result is temporarily stored in the circuit as a comparison phase signal. The system phase signal and the comparison phase signal are phase-compared by a stop circuit. When a phase difference between the system phase signal and the comparison phase signal exceeds a predetermined value, the stop circuit stops the operation of the inverter.

Voltage-phase responsive, inverter disable circuit for system

In a method of and a system for controlling a photovoltaic power system including a solar battery and a power converter receiving the output of the solar battery, the voltage of the solar battery is kept at a voltage reference which is determined in accordance with the operating condition of the system thereby to maximize the power of the solar battery. Operating mode is switched between a first mode in which the voltage reference is periodically decreased and a second mode in which the voltage reference is periodically increased. The switching between the first and the second mode is effected in accordance with the direction of change of the power and the voltage of the solar battery. Where there is a reactance between the solar battery and the point at which the voltage or the current is detected, or a time lag element in a voltage detector or a current detector, an arrangement may be provided to compensate detection error due to the reactance or the time lag element.

Method of and system for controlling a photovoltaic power system

An inverter apparatus includes a plurality of gate-turn-off thyristors being provided at each end of thyristor-branches, and bias sources or capacitors connected in parallel with the gate-turn-off thyristors for applying reverse voltage to the thyristor-branches when the gate-turn-off thyristor is turned off.

Inverter apparatus

A control apparatus for a cycloconverter includes m sets of bridge converters connected between the input terminals of an m-phase load (m.gtoreq.3) and is applied for a cycloconverter of which the common connection point of the bridge converters is disconnected from a neutral point of the load. The output voltage of each bridge converter is controlled by a reference voltage signal during a 1/m period of one cycle of the load voltage. The center of the 1/m period is located at a positive or negative maximum amplitude point of the load voltage. The output voltage is also controlled during the remaining period of (1-1/m) by a phase control input signal corresponding to a difference between a reference current signal and the load current. The reference voltage signal and the phase control input signal are selected by switching signals from a logic circuit for detecting phase voltages of the load to alternately be applied to the phase control circuits.

Control apparatus for a cycloconverter

In a control system of an AC motor fed from a frequency converter including a thyristor rectifier and a thyristor inverter, the speed of the motor is controlled by a current control system comprising a speed control circuit responsive to a reference speed signal and an actual speed signal, and a current control circuit which produces a pulse signal supplied to the rectifier. The inverter is controlled by another pulse signal corresponding to the angular position of the rotor of the motor. An additional current instruction circuit is provided which in response to the two pulse signals described above controls the current control circuit.

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Yokohama, Japan

Kihei Nakajima