Variable frequency independent speed motor control based on flux estimate

Patent metadata

Field	Value
Publication number	US-11146200-B2
Application number	US-202016814043-A
Country	US
Kind code	B2
Filing date	Mar 10, 2020
Priority date	Mar 10, 2020
Publication date	Oct 12, 2021
Grant date	Oct 12, 2021

Abstract

A system for controlling a motor may include an alternating current (AC) bus configured to transmit an AC power signal to a set of stator windings, where the AC power signal produces a first rotating magnetic flux at the set of stator windings. The system may also include a high frequency contactless transformer configured to transmit an excitation signal to a set of rotor windings, where the excitation signal produces a second rotating magnetic flux at the rotor. The system may also include electrical circuitry configured to determine a rotor voltage and a rotor current associated with the excitation signal, determine a rotor flux magnitude estimate and a rotor flux angle estimate based on the rotor voltage and the rotor current, and determine an inverter control signal operable to generate the excitation signal based at least partially on the rotor flux magnitude estimate and the rotor flux angle estimate.

First claim

What is claimed is:

1. A system comprising:
a motor having a stator, a rotor, a set of stator windings, and a set of rotor windings;
an alternating current (AC) bus configured to transmit an AC power signal to the set of stator windings, wherein the AC power signal produces a first rotating magnetic flux at the set of stator windings;
a high frequency contactless transformer configured to transmit an excitation signal from the stator to the rotor, wherein the excitation signal is received at the set of rotor windings, and wherein the excitation signal produces a second rotating magnetic flux at the rotor; and
electrical circuitry configured to determine a rotor voltage and a rotor current associated with the excitation signal, determine a rotor flux magnitude estimate and a rotor flux angle estimate based on the rotor voltage and the rotor current, and determine an inverter control signal operable to generate the excitation signal based at least partially on the rotor flux magnitude estimate and the rotor flux angle estimate.

2. The system of claim 1 , wherein the electrical circuitry is further configured to determine a stator voltage and a stator current associated with the AC power signal, determine a stator flux magnitude estimate and a stator flux angle estimate based on the stator voltage and the stator current, and determine a phase angle difference based on the rotor flux angle estimate, a rotor shaft angle, and the stator flux angle estimate, wherein the inverter control signal is further based at least partially on the phase angle difference.

3. The system of claim 2 , wherein the electrical circuitry is further configured to determine a torque estimation based on the rotor flux magnitude estimate, the stator flux magnitude estimate, and the phase angle difference, wherein the inverter control signal is further based at least partially on the torque estimation.

4. The system of claim 3 , wherein the electrical circuitry is further configured to determine a reference rotor flux angle by offsetting a difference between the stator flux angle estimate and the rotor shaft angle by 90 degrees, wherein the inverter control signal is further based at least partially on the reference rotor flux angle.

5. The system of claim 4 , wherein the electrical circuitry is further configured to determine a flux lookup value based on a difference between a reference rotor flux magnitude and the rotor flux magnitude estimate, determine a torque lookup value based on a difference between a reference torque and the torque estimation, determine a sector lookup value based on the reference rotor flux angle, wherein the inverter control signal is determined by using a lookup table with the flux lookup value, the torque lookup value, and the sector lookup value as inputs.

6. The system of claim 5 , wherein the electrical circuitry is further configured to determine the reference torque based on a difference between a reference shaft speed and a rotor shaft speed.

7. The system of claim 1 , further comprising a direct current (DC) bus and a 3-phase inverter for generating the excitation signal using a DC power signal from the DC bus.

8. The system of claim 1 , wherein the electrical circuitry implements a controller that includes at least one processor and memory, wherein the memory stores instructions that are executable by the at least one processor, wherein determining the rotor flux magnitude estimate and the rotor flux angle estimate, determining a stator flux magnitude estimate and a stator flux angle estimate, determining a phase angle difference, determining a torque estimation, determine a reference rotor flux angle, determining a flux lookup value, determine a torque lookup value, determine a sector lookup value, and determining the inverter control signal operable to generate the excitation signal is performed at the processor.

9. The system of claim 1 , wherein the motor, the AC bus, a DC bus, the high frequency contactless transformer, and the electrical circuitry are incorporated into a vehicle.

10. A method comprising:
transmitting an alternating current (AC) power signal from an AC bus to a set of stator windings at a stator of a motor, wherein the AC power signal produces a first rotating magnetic flux at the set of stator windings;
transmitting an excitation signal from the stator to a set of rotor windings at a rotor of the motor via a high frequency contactless transformer, wherein the excitation signal produces a second rotating magnetic flux at the rotor;
determining a rotor voltage and a rotor current associated with the excitation signal;
determining a rotor flux magnitude estimate and a rotor flux angle estimate based on the rotor voltage and the rotor current;
determining an inverter control signal operable to generate the excitation signal based at least partially on the rotor flux magnitude estimate and the rotor flux angle estimate; and
sending the inverter control signal to an inverter; and
generating the excitation signal at the inverter.

11. The method of claim 10 , further comprising:
determining a stator voltage and a stator current associated with the AC power signal;
determining a stator flux magnitude estimate and a stator flux angle estimate based on the stator voltage and the stator current; and
determining a phase angle difference based on the rotor flux angle estimate, a rotor shaft angle, and the stator flux angle estimate, wherein the inverter control signal is further based at least partially on the phase angle difference.

12. The method of claim 11 , further comprising:
determining a torque estimation based on the rotor flux magnitude estimate, the stator flux magnitude estimate, and the phase angle difference, wherein the inverter control signal is further based at least partially on the torque estimation.

13. The method of claim 12 , further comprising:
determining a reference rotor flux angle by offsetting a difference between the stator flux angle estimate and the rotor shaft angle by 90 degrees.

14. The method of claim 13 , further comprising:
determining a flux lookup value based on a difference between a reference rotor flux magnitude and the rotor flux magnitude estimate;
determining a torque lookup value based on a difference between a reference torque and the torque estimation;
determining a sector lookup value based on the reference rotor flux angle, wherein the inverter control signal is determined by using a lookup table with the flux lookup value, the torque lookup value, and the sector lookup value as inputs.

15. The method of claim 14 , further comprising:
determining the reference torque based on a difference between a reference shaft speed and a rotor shaft speed.

16. The method of claim 10 , wherein the inverter is a 3-phase inverter powered by a direct current (DC) power signal from a DC bus ( 193 ).

17. A system comprising one or more processors and memory, the memory storing instructions that, when executed by the processor, cause the processor to:
determine a rotor voltage and a rotor current associated with an excitation signal that is transmitted from a stator of a motor to a set of rotor windings at a rotor of the motor via a high frequency contactless transformer, wherein the excitation signal produces a rotating magnetic flux at the rotor;
determine a rotor flux magnitude estimate and a rotor flux angle estimate based on the rotor voltage and the rotor current; and
determine an inverter control signal operable to generate the excitation signal based at least partially on the rotor flux magnitude estima

Assignees

• Boeing Co

Inventors

• Gao Lijun
• Liu Shengyi

Classifications

• H02P25/03 Primary

  with brushless excitation · CPC title

• H02P21/28

  Stator flux based control · CPC title

• H02P21/141

  Flux estimation · CPC title

• H02P21/20

  Estimation of torque · CPC title

• H02P27/047 Primary

  V/F converter, wherein the voltage is controlled proportionally with the frequency · CPC title