公开(公告)号：US20240405704A1

公开(公告)日：2024-12-05

申请号：US18674130

申请日：2024-05-24

Applicant: ABB Schweiz AG

Inventor： Lennart Harnefors ,  Omer Ikram Ul Haq ,  Sjoerd Bosga

IPC: H02P23/04

Abstract: A method of reducing vibrations in an electric motor including a rotor and a stator, by means of an active vibration controller, AVC, the method includes: a) determining whether one of an angular rotational speed of the rotor and an angular stator frequency multiplied by two is within a critical range including a mechanical resonance frequency of a motor assembly including the electric motor and its load, b) i) setting an oscillating incremental torque angular frequency of the AVC to the angular rotational speed of the rotor if the angular rotational speed of the rotor is within the critical range, or ii) setting the oscillating incremental torque angular frequency to the angular stator frequency multiplied by two if the angular stator frequency multiplied by two is within the critical range, iii) generating an oscillating incremental torque reference using the AVC with the oscillating incremental torque angular frequency set in step b i) or b ii), and iv) controlling the electric motor based on a sum of the oscillating incremental torque reference and an electrical torque reference; or c) i) deactivating the AVC if the angular rotational speed of the rotor and the angular stator frequency multiplied by two is outside the critical range, and ii) controlling the electric motor based on the electrical torque reference.

公开(公告)号：US20170099019A1

公开(公告)日：2017-04-06

申请号：US15122854

申请日：2015-03-31

Applicant: ABB SCHWEIZ AG

Inventor： Sjoerd Bosga ,  Veli-Matti Leppanen ,  Mehanathan Pathmanathan ,  Robert Chin ,  Yujing Liu

IPC: H02P6/15

CPC classification number: H02P6/15 ,  H02P6/26

Abstract: A commutation circuit includes a coil connected to an H bridge, the H bridge including four main switches for reversing polarity and a resulting coil current in the coil. The commutation circuit further includes a voltage source configured to generate a bypass current, and at least one auxiliary switch for controlling the bypass current to thereby decrease a switch current through at least one of the main switches. By generating an appropriate bypass current with help of a voltage source, a switch current through a desired main switch in a leading state can be decreased and eventually brought to zero. Zero current in its turn enables the use of thyristors as main switches as it results in the thyristors to be turned off automatically. Furthermore, decreased switch current at the switching moment reduces switching losses even in different types of switches such as GTOs and IGBTs.