公开(公告)号：US20160334468A1

公开(公告)日：2016-11-17

申请号：US14710796

申请日：2015-05-13

Applicant: Schweitzer Engineering Laboratories, Inc.

Inventor： Subhash C. Patel ,  George E. Alexander

IPC: G01R31/34

CPC classification number: G01R31/343 ,  H02H7/0855

Abstract: Detection of a locked rotor condition of an electric motor during startup herein uses a virtual speed switch. The methods and systems herein determine whether the motor is in a starting state, and the monitor the motor current to determine if it is greater than a predetermined threshold, and that the motor current decrease exceeds a predetermined threshold after a predetermined amount of time. If the decrease in motor current is not less than a predetermined threshold, then a speed switch bit is set, indicating that the rotor is turning. The methods and systems herein further determine whether a physical speed switch is faulty, and determine a locked rotor condition using the virtual speed switch signal, a physical speed switch signal, and whether the physical speed switch is faulty.

Abstract translation: 在启动期间检测电动机的转子转子状态使用虚拟速度开关。 这里的方法和系统确定电动机是否处于起动状态，并且监视电动机电流以确定其是否大于预定阈值，并且在预定时间量之后电动机电流下降超过预定阈值。 如果电动机电流的下降不小于预定阈值，则设定转速开关位，表示转子转动。 这里的方法和系统进一步确定物理速度开关是否有故障，并且使用虚拟速度开关信号，物理速度开关信号以及物理速度开关是否有故障来确定锁定的转子状况。

公开(公告)号：US09939492B2

公开(公告)日：2018-04-10

申请号：US14710796

申请日：2015-05-13

Applicant: Schweitzer Engineering Laboratories, Inc.

Inventor： Subhash C. Patel ,  George E. Alexander

IPC: G01R31/02 ,  G01R27/28 ,  G01R31/34

CPC classification number: G01R31/343 ,  H02H7/0855

Abstract: Detection of a locked rotor condition of an electric motor during startup herein uses a virtual speed switch. The methods and systems herein determine whether the motor is in a starting state, and the monitor the motor current to determine if it is greater than a predetermined threshold, and that the motor current decrease exceeds a predetermined threshold after a predetermined amount of time. If the decrease in motor current is not less than a predetermined threshold, then a speed switch bit is set, indicating that the rotor is turning. The methods and systems herein further determine whether a physical speed switch is faulty, and determine a locked rotor condition using the virtual speed switch signal, a physical speed switch signal, and whether the physical speed switch is faulty.