Method for hot connecting a motor to a variable speed drive

摘要

A method for connecting a second motor to a variable speed drive in parallel with at least one existing motor under load and controlled by the variable speed drive is provided. The method disconnects the existing motor from the variable speed drive and a state estimator calculates transient state of the existing motor including at least the speed of the existing motor based on a previously established load model. The method then connects the second motor to the variable speed drive and the second motor is operated using a suitable directive until the actual state of the second motor attains the calculated transient state of the existing motor at a given time. Upon attaining the calculated transient state, the existing motor is reconnected to the variable speed drive such that no current spike is generated in the aforementioned process.

主权项

1. Method for connecting an additional motor to a variable speed drive in parallel with at least one first motor under load, controlled by the said variable speed drive,
comprising the following steps:
Disconnecting the at least one first motor from the variable speed drive;Implementing a state estimator of the at least one first motor, based on a previously established load model of the said at least one first motor, the said state estimator being able to calculate the evolution over time of an estimated state of the at least one first motor, the said estimated state comprising at least the speed of the said at least one first motor;Connecting the additional motor to the variable speed drive;Starting the additional motor with the directive of attaining the estimated state of the at least one first motor;When the state of the additional motor attains the estimated state of the at least one first motor, reconnecting the said at least one first motor.