Control sub-system and related method of controlling electric machine in fluid extraction system

Patent metadata

Field	Value
Publication number	US-2017077847-A1
Application number	US-201514939221-A
Country	US
Kind code	A1
Filing date	Nov 12, 2015
Priority date	Sep 15, 2015
Publication date	Mar 16, 2017
Grant date	—

Abstract

A control sub-system for controlling an electric machine is presented. The control sub-system includes a phase shift control unit to receive an electric signal indicative of an angular position of a rotor. The phase shift control unit generates a phase shifted electric signal by applying a phase shift to the electric signal. The magnitude of the phase shift is determined based on a speed control signal. The phase shift control unit is configured to generate a phase command signal based on the phase shifted electric signal. The control sub-system also includes a switching unit to control a supply of a phase current to one or more phase windings the electric machine based on the phase command signal such that the rotor is operated at a predetermined rotational speed. Related method of controlling the electric machine is also presented.

First claim

1 . A control sub-system for controlling an electric machine, the control sub-system comprising:
a phase shift control unit configured to:
receive an electric signal indicative of an angular position of a rotor of the electric machine from at least one rotor position sensor of the electric machine;
generate a phase shifted electric signal by applying a phase shift to the electric signal, wherein a magnitude of the phase shift is determined based at least on a speed control signal indicative of a predetermined rotational speed of the rotor;
generate a phase command signal based on the phase shifted electric signal; and
a switching unit electrically coupled to the phase shift control unit and configured to control a supply of a phase current to one or more phase windings of a plurality of phase windings of the electric machine based on the phase command signal such that the rotor is operated at the predetermined rotational speed.

2 . The control sub-system of claim 1 , wherein the phase shift control unit is further configured to receive the speed control signal from a controller remote from the control sub-system.

3 . The control sub-system of claim 1 , wherein the phase command signal indicates a polarity of the phase current to be applied to the one or more of the plurality of phase windings.

4 . The control sub-system of claim 1 , wherein the switching unit comprises a gate drive unit electrically coupled to the phase shift control unit and configured to generate a plurality of control signals based on the phase command signal.

5 . The control sub-system of claim 4 , wherein the switching unit further comprises a switching assembly having a plurality of semiconductor switches for selectively supplying the phase current to one or more of the plurality of phase windings based on the plurality of control signals.

6 . The control sub-system of claim 5 , wherein each of the plurality of semiconductor switches comprises a control terminal, wherein the control terminal is coupled to the gate drive unit for receiving a corresponding control signal of the plurality of control signals.

7 . The control sub-system of claim 5 , wherein the plurality of semiconductor switches comprises transistors, gate commutated thyristors, field effect transistors, insulated gate bipolar transistors, gate turn-off thyristors, static induction transistors, static induction thyristors, or combinations thereof.

8 . The control sub-system of claim 5 , wherein the plurality of semiconductor switches is made of silicon (Si), silicon carbide (SiC), gallium nitride (GaN), or combinations thereof.

9 . The control sub-system of claim 4 , wherein the gate drive unit comprises a pulse width modulation (PWM) sub-unit configured to apply PWM to one or more of the plurality of control signals based on amplitude of the phase current.

10 . The control sub-system of claim 1 , wherein the switching unit is further electrically coupled to a direct current (DC) bus, and wherein the phase current is received from the DC-bus.

11 . The control sub-system of claim 10 , wherein a maximum rotational speed of the rotor in the electric machine depends on a DC voltage level of the DC-bus.

12 . A method for controlling an electric machine, comprising:
receiving an electric signal indicative of an angular position of a rotor of the electric machine from at least one rotor position sensor; generating a phase shifted electric signal by applying a phase shift to the electric signal, wherein a magnitude of the phase shift is determined based at least on a speed control signal indicative of a predetermined rotational speed of the rotor; generating a phase command signal based on the phase shifted electric signal; and selectively supplying a phase current to one or more of a plurality of phase windings based on the phase command signal such that the rotor is operated at the predetermined rotational speed.

13 . The method of claim 12 , further comprising receiving the speed control signal from a controller disposed outside a well.

14 . The method of claim 12 , further comprising generating a plurality of control signals based on the phase command signal.

15 . The method of claim 14 , further comprising applying pulse width modulation to one or more of the plurality of control signals based on amplitude of the phase current.

16 . The method of claim 14 , wherein selectively supplying the phase current comprises selectively supplying the phase current to one or more of the plurality of phase windings based on the plurality of control signals.

Assignees

• Gen Electric

Inventors

• Torrey David Allan
• Hawes Jr Nathaniel Benedict
• El-Refaie Ayman Mohamed Fawzi
• Chishti Muhammad Hassan

Classifications

• H02P6/18

  without separate position detecting elements · CPC title

• E21B43/017

  Production satellite stations, i.e. underwater installations comprising a plurality of satellite well heads connected to a central station · CPC title

• H02P6/00

  Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor (vector control H02P21/00) · CPC title

• H02P6/12

  Monitoring commutation; Providing indication of commutation failure · CPC title

• H02P6/14

  Electronic commutators · CPC title