Power conversion device
    1.
    发明授权

    公开(公告)号:US11632060B2

    公开(公告)日:2023-04-18

    申请号:US17425779

    申请日:2019-04-02

    IPC分类号: H02M7/483 H02M1/32 H02M1/00

    摘要: A power conversion device that performs power conversion between a DC circuit and an AC circuit includes a power conversion circuit including a plurality of sub-modules, a failure detection device that detects an internal failure of the power conversion circuit, and a control device that generates an operation command controlling operation of each of the plurality of sub-modules. The control device acquires a voltage value of a capacitor included in each sub-module, calculates a deviation between a variance value indicating a variation in the voltage value of the capacitor included in the sub-module in a reference period and a reference variance value in the sub-module for each of a plurality of sub-modules, determines a failure section of an internal failure based on the deviation in each sub-module when the internal failure is detected, and outputs an operation command based on a determination result to each sub-module.

    Power control system and controller for power control system

    公开(公告)号:US11936307B2

    公开(公告)日:2024-03-19

    申请号:US17283297

    申请日:2018-11-28

    摘要: A power converter includes first and second arms, each having switching elements, and performs power conversion between a DC system and an AC system. An AC circuit breaker and a current control circuit are connected in series between the AC system and the power converter. The current control circuit includes a current-limiting resistor and a disconnector connected in parallel. A controller instructs a disconnector to close after an initial charge of the power converter and opens the AC circuit breaker when an impedance of a line between a first node located on a first end side of the current control circuit and a second node located on a second end side of the current control circuit is not less than a first threshold and an accumulated value of a current flowing through the current control circuit within a certain period of time is not less than a second threshold.

    Power conversion device having a frequency of a first control signal higher than a frequency of a second control signal

    公开(公告)号:US11601064B2

    公开(公告)日:2023-03-07

    申请号:US16958400

    申请日:2018-01-12

    IPC分类号: H02M7/483 H02M7/5387

    摘要: In one embodiment, a power conversion device that converts power between a DC circuit and an AC circuit includes a plurality of leg circuits connected in parallel between first and second DC terminals and electrically connected to the AC circuit. Each of the plurality of leg circuits includes at least one first converter cell and a plurality of second converter cells other than the first converter cell. A first control signal that controls switching of a semiconductor switching element included in at least one first converter cell is higher in frequency than a second control signal that controls switching of a semiconductor switching element included in each of the plurality of second converter cells.

    Fault tolerant multilevel modular power conversion device

    公开(公告)号:US11081974B2

    公开(公告)日:2021-08-03

    申请号:US16639619

    申请日:2017-10-04

    摘要: A power conversion device includes: first and second control devices that generate first and second control commands respectively; and first and second relay devices that transmit, to each sub module, the first and second control commands respectively. The first and second control devices receive instruction information indicating a system that is to control operation of each sub module. The first and second control commands each include a drive command, abnormality determination information about the control device, and instruction information. Even when the instruction information indicates a first system, each sub module selects a second system as a system to control operation of each sub module in response to detection of occurrence of abnormality to the first control device, and performs PWM control for a switching element in accordance with the drive command included in the second control command for the second system.

    Power conversion device that limits voltage variation among energy storage devices

    公开(公告)号:US10790764B2

    公开(公告)日:2020-09-29

    申请号:US16605577

    申请日:2018-05-29

    摘要: A power conversion device includes an MMC-type power conversion circuit and a central controller. The central controller limits an active power command value and a reactive power command value to a value corresponding to an active power limit value and a value corresponding to a reactive power limit value, respectively, and controls an operation of the power conversion circuit according to the limited active power command value and the limited reactive power command value. The central controller includes: an index value calculation unit configured to calculate an index value that shows an extent of a variation among voltages of energy storage devices included in a plurality of converter cells; and a limiter controller configured to change the active power limit value to a value smaller than the active power limit value when the index value exceeds a threshold value.