公开(公告)号：US20210328495A1

公开(公告)日：2021-10-21

申请号：US17273038

申请日：2018-09-03

Applicant: ABB Power Grids Switzerland AG

Inventor： Xinhua Ke ,  Beat Buchmann

IPC: H02M1/00 ,  H02M5/04 ,  G05B6/02

Abstract: A method performed by a control system of a power electronics converter. A first part of a grid-side current controller runs a first feedback control algorithm having a first control cycle time and includes at least proportional control using a proportional gain. A third part of the controller runs a third feedback control algorithm having the first control cycle time and acting on an output from the first control algorithm after SOA limits have been applied and includes counteracting the proportional control of the first feedback control algorithm. A second part of the controller runs a second feedback control algorithm having a second control cycle time, less than the first control cycle time, and acting on an output from the third control algorithm with the same polarity as the first control algorithm and includes proportional control using the proportional gain.

公开(公告)号：US10855199B2

公开(公告)日：2020-12-01

申请号：US15781006

申请日：2015-12-18

Applicant: ABB Power Grids Switzerland AG

Inventor： Beat Buchmann ,  Jerome Fischer

IPC: H02M7/483 ,  H02J3/18 ,  H02M1/32

Abstract: A method of discharging a Modular Multilevel Converter (MMC) includes a plurality of phase legs connected in delta configuration. Each leg includes a plurality of series connected submodules, each submodule including an energy storage. The method includes disconnecting the MMC from an electrical grid, discharging the energy storages by means of a circulating current, and reconnecting the MMC to the electrical grid. The discharging includes, for each phase leg, setting a voltage reference, and sequentially selecting submodules in zero state by means of a sorting algorithm for switching each of the selected submodules to plus or minus state until the voltage deviation from the set voltage reference of the energy storage of each submodule in the phase leg is within a predefined range.