Kabushiki Kaisha Yaskawa Denki

Other

Masashiro Tanaka

Keisei Inoki

Yoichi Yamamoto

Hirotaka Karakama

Hidenori Hara

Toshihiro Hanada

Shigekazu Nakamura

Yoichi Yano

Shoji Konakahara

Takahiro Uchino

Hiroaki Ohya

Hiroshi Suetake

Mitsugu Tajima

A power conversion deviceincludes a matrix converter circuitincluding a plurality of switching elements and being configured to perform bidirectional power conversion between alternating current power on a primary side and alternating current power on a secondary side, a power conversion control unitconfigured to switch on and off the plurality of switching elements in unison with a carrier wave to cause an alternating current on the secondary side to follow a control command, and a carrier wave changing unitconfigured to change, based on a nearness level between a frequency on the primary side and a frequency on the secondary side, a frequency of the carrier wave.

Power conversion device, power conversion method, and program

A power conversion apparatus includes: matrix converter circuitry configured to perform bidirectional power conversion between a primary side and a secondary side; and control circuitry configured to: select a first control mode in response to determining that a command-primary frequency difference between a command frequency and a primary side frequency of the matrix converter circuitry is above a predetermined threshold, wherein the first control mode includes causing a secondary side frequency of the matrix converter circuitry to follow the command frequency; select a second control mode in response to determining that the command-primary frequency difference is below the threshold, wherein the second control mode includes maintaining a primary-secondary phase difference between a secondary side phase and a primary side phase of the matrix converter circuitry within a predetermined target range; and control the matrix converter circuitry in accordance with a selection of the first control mode or the second control mode.

Bidirectional power conversion

A power conversion apparatus includes: matrix converter circuitry to perform power conversion between a primary side electric power and a secondary side electric power; rectifier circuitry to convert the primary side electric power to charge a capacitor; and control circuitry to: set a changeover reference voltage at a first reference voltage when the primary side voltage magnitude is a first voltage magnitude and set the changeover reference voltage at a second reference voltage when the primary side voltage magnitude is a second voltage magnitude; and select, based on the changeover reference voltage and the terminal voltage, a connection state from: a first connection state in which the rectifier circuitry is connected to the capacitor by a first route including a current limit device; and a second connection state in which the rectifier circuitry is connected to the capacitor by a second route that bypasses the current limit device.

Bidirectional power converter

An elevator control device includes a vector controller that calculates a voltage command required for driving an elevator cage, a carrier frequency switch circuit that outputs a carrier frequency signal, and a power converter that performs PWM control based on the voltage command and the carrier frequency signal, generates an AC power and supplies the AC power to an AC motor. The carrier frequency switch circuit changes the carrier frequency signal when a torque command for driving the AC motor reaches a torque limit value. Thus, it is possible to continuously operate an elevator without causing damage to a switching element of the power converter.

Elevator control device with carrier frequency switch circuit

A simple and accurate dead time dispersion measurement method and a voltage source inverter control method that can prevent the occurrence of an unstable phenomenon are provided. The control method controls a voltage source inverter of a PWM system, which includes a power semiconductor device controlling a level of a voltage, a frequency and a phase. According to the control method, before operation, voltage error information for each polarity of respective phase currents of the inverter is stored. And during the operation, the voltage error information is read to compensate for a voltage instruction value or a pulse width of a PWM instruction signal, so that a voltage error can be corrected.

Voltage source inverter control method

Growing community of inventors

Fukuoka, Japan

Masashiro Tanaka