Toshiba Mitsubishi-electric Industrial Systems Corporation

Tmeic Corporation

Naoto Niimura

Teruo Yoshino

Toshiaki Oka

Hiromitsu Suzuki

According to an embodiment, a power conversion system includes a plurality of converters and a control unit. The plurality of converters are provided in parallel for each phase of a multi-phase alternating current power system. The control unit uses a plurality of carrier signals having a prescribed phase difference from each other in carrier comparison type pulse width modulation (PWM) control. The control unit detects a current of a primary side of the plurality of converters at each of four or more even-numbered timings when the four or more even-numbered timings are defined at prescribed time intervals during one cycle of a specific carrier signal among the plurality of carrier signals. The control unit generates a reference voltage for the PWM control using a value of the detected current of the primary side and a value of a reference current of the primary side and updates the reference voltage at each of the four or more even-numbered timings. The control unit controls a specific converter among the plurality of converters using the specific carrier signal and the updated reference voltage.

Power conversion system and power conversion control method

A power conversion device in an embodiment includes a first power converter; a plurality of direct current-direct current (DCDC) converter devices; and a second power converter. The first power converter includes a plurality of first positive-side arms; a plurality of first negative-side arms; a first positive-side star connection line configured to connect the plurality of first positive-side arms in a star shape; a first negative-side star connection line configured to connect the plurality of first negative-side arms in a star shape; and a first terminal configured to connect the first positive-side star connection line and the first negative-side star connection line to each phase of a power supply side alternating current (AC) system and the plurality of first positive-side arms and the plurality of first negative-side arms mutually convert a first AC power and a first DC power of the power supply side AC system. A plurality of DCDC converter devices mutually convert the first DC power and the second DC power. The second power converter includes a plurality of second positive-side arms; a plurality of second negative-side arms; a second positive-side star connection line configured to connect the plurality of second positive-side arms in a star shape; a second negative-side star connection line configured to connect the plurality of second negative-side arms in a star shape; and a second terminal configured to connect the second positive-side star connection line and the second negative-side star connection line to each phase of a load-side AC system, and the plurality of second positive-side arms and the plurality of second negative-side arms mutually convert the second DC power and the second AC power.

Power conversion device and power conversion control device

In a power converter, a first single-phase AC conversion unit, which is connected to a first line of a first phase and a second line of a second phase of a first three-phase AC, a second single-phase AC conversion unit, which is connected to the second line of the second phase and a third line of a third phase of the first three-phase AC, and a third single-phase AC conversion unit, which is connected to the third line of the third phase and the first line of the first phase of the first three-phase AC, form a delta-connected load for an AC power supply system. At least the first single-phase AC conversion unit, the second single-phase AC conversion unit, and the third single-phase AC conversion unit form a first set in which respective output terminals are connected in series to one another, and the first set, and a second set and a third set, which are different from the first set, form each phase of a star connected power supply. A reactive power control unit controls a reactive power of a converter of each single-phase AC conversion unit based on a reactive power command value generated based on an acquired value related to an active power.

Power conversion device, motor driving system, and control method

An inverter test apparatus includes a DC power supply, a second inverter which is connected to a DC side of the first inverter, an inductor which is connected between an AC side of the first inverter and an AC side of the second inverter, a first controller which controls an AC voltage of the first inverter to be at a constant amplitude and a constant frequency, a current detector which detects a current that flows through the inductor, a phase command value computation module which computes a phase command value of the second inverter so as to control the current detected by the current detector, and a second controller which controls a phase of the second inverter, based on the phase command value computed.

Growing community of inventors

Tokyo, Japan

Naoto Niimura