STARTUP SEQUENCE FOR CENTRIFUGAL PUMP WITH LEVITATED IMPELLER

摘要

A centrifugal pump system having an impeller rotating with first and second magnetic structures on opposite surfaces. A levitation magnetic structure is disposed at a first end of a pump housing having a levitating magnetic field for axially attracting the first magnetic structure. A multiphase magnetic stator at a second end of the pump housing generates a rotating magnetic field for axially and rotationally attracting the second magnetic structure. A commutator circuit provides a plurality of phase voltages to the stator. A sensing circuit determines respective phase currents. A controller calculates successive commanded values for the phase voltages during a running state in response to a desired impeller speed and an actual impeller phase. The controller has a startup interval during which the commanded values of the phase voltages are determined in response to a pseudo impeller phase and in response to a ramping gain factor.

主权项

1. A centrifugal pump system comprising:
a disc-shaped impeller rotating about an axis and having a first magnetic structure disposed at a first surface and a second magnetic structure disposed at a second surface; a pump housing defining a pumping chamber which receives the impeller; a levitation magnetic structure disposed at a first end of the pump housing having a levitating magnetic field for axially attracting the first magnetic structure; a multiphase magnetic stator disposed at a second end of the pump housing for generating a rotating magnetic field for axially and rotationally attracting the second magnetic structure; a commutator circuit for providing a plurality of phase voltages to the stator; a sensing circuit determining respective phase currents flowing in response to the phase voltages; and a controller calculating successive commanded values for the phase voltages during a running state in response to a desired impeller speed and an actual impeller phase that is detected in response to the determined phase currents, wherein the controller has a startup interval during which the commanded values of the phase voltages are determined in response to a pseudo impeller phase and in response to a ramping gain factor.