Interpolation of homotopic operating states

Patent metadata

Field	Value
Publication number	US-10590942-B2
Application number	US-201715836701-A
Country	US
Kind code	B2
Filing date	Dec 8, 2017
Priority date	Dec 8, 2017
Publication date	Mar 17, 2020
Grant date	Mar 17, 2020

Abstract

A system for real-time modeling includes a compressor designed to operate at a compressor speed, a compressor flow rate, and a compressor pressure ratio. The system also includes a memory designed to store an operating condition matrix that plots multiple compressor pressure ratios to each of a plurality of compressor speeds, and a related operating state matrix that plots multiple compressor flow rates to each of the plurality of compressor speeds. The system also includes a compressor controller to determine a target compressor speed and a target compressor pressure ratio, and to identify a target location in the operating condition matrix based on the target compressor speed and the target compressor pressure ratio. The compressor controller also determines a target compressor flow rate by interpolating values in the operating state matrix based on the target location, and to control the compressor based on the target compressor flow rate.

First claim

What is claimed is:

1. A system for real-time controller modeling, comprising:
a compressor having an inlet and an outlet and configured to operate at a compressor speed, a compressor flow rate corresponding to a flow of fluid through the compressor, and a compressor pressure ratio corresponding to a ratio of an inlet pressure at the inlet to an outlet pressure at the outlet;
a memory configured to store an operating condition matrix that plots multiple compressor pressure ratios to each of a plurality of compressor speeds, and an operating state matrix that plots multiple compressor flow rates to each of the plurality of compressor speeds, the operating condition matrix being related to the operating state matrix such that a first compressor pressure ratio at a first location of the operating condition matrix corresponds to a first compressor flow rate at a corresponding location of the operating state matrix; and
a compressor controller coupled to the compressor and the memory and configured to:
determine a current or target compressor speed and a current or target compressor pressure ratio,
create a pressure ratio array by interpolating between the multiple compressor pressure ratios corresponding to two of the plurality of compressor speeds based on the current or target compressor speed,
identify a current or target pressure ratio array location using the pressure ratio array,
identify a current or target location in the operating condition matrix based on the current or target pressure ratio array location,
identify the current or target pressure ratio array location by identifying two of the multiple compressor pressure ratios of the pressure ratio array that are nearest to the current or target compressor pressure ratio and identifying a distance from the current or target compressor pressure ratio to at least one of the two of the multiple compressor pressure ratios,
determine a current or target compressor flow rate by interpolating values in the operating state matrix based on the current or target location, and control the compressor based on the current or target compressor flow rate.

2. The system of claim 1 wherein the compressor controller is further configured to: create a flow array by interpolating between the multiple compressor flow rates corresponding to the two of the plurality of compressor speeds based on the current or target compressor speed; and determine the current or target compressor flow rate by interpolating between two of the multiple compressor flow rates based on the current or target pressure ratio array location.

3. The system of claim 1 wherein:
the compressor is configured to operate between a stall line beyond which the compressor operates in a stall condition, and a surge line beyond which the compressor operates in a surge condition; and
the operating condition matrix includes a first plurality of rows each corresponding to one of the plurality of compressor speeds, and a first plurality of columns each corresponding to equally spaced locations along the plurality of compressor speeds between the stall line and the surge line, each cell of the operating condition matrix including a pressure ratio value.

4. The system of claim 3 wherein the operating state matrix includes a second plurality of rows each corresponding to the one of the plurality of compressor speeds of the operating condition matrix, and a second plurality of columns each corresponding to the equally spaced locations along the plurality of compressor speeds between the stall line and the surge line, a first quantity of the first plurality of columns being equal to a second quantity of the second plurality of columns.

5. The system of claim 1 further comprising a fuel cell stack configured to facilitate a chemical reaction between air and hydrogen to generate electricity, wherein:
the fuel cell stack and the compressor are configured for use in a vehicle;
the compressor is configured to pump the air to the fuel cell stack; and
the compressor controller is an electronic control unit (ECU) of the vehicle.

6. The system of claim 1 wherein the compressor speed, the compressor flow rate, and the compressor pressure ratio are homotopic operating states.

7. A method for real-time modeling of a compressor that is designed to operate between a stall line beyond which the compressor operates in a stall condition, and a surge line beyond which the compressor operates in a surge condition, the method comprising:
storing, in a memory, an operating condition matrix that plots multiple compressor pressure ratios to each of a plurality of compressor speeds;
storing, in the memory, an operating state matrix that plots multiple compressor flow rates to each of the plurality of compressor speeds, the operating condition matrix being related to the operating state matrix such that a first compressor pressure ratio at a first location of the operating condition matrix corresponds to a first compressor flow rate at a corresponding location of the operating state matrix, the operating condition matrix including a first plurality of rows each corresponding to one of the plurality of compressor speeds and a first plurality of columns each corresponding to equally spaced locations along the plurality of compressor speeds between the stall line and the surge line, each cell of the operating condition matrix including a pressure ratio value;
determining, by a compressor controller, a current or target compressor speed and a current or target compressor pressure ratio;
identifying, by the compressor controller, a current or target location in the operating condition matrix based on the current or target compressor speed and the current or target compressor pressure ratio;
determining, by the compressor controller, a current or target compressor flow rate by interpolating values in the operating state matrix based on the current or target location; and
controlling, by the compressor controller, the compressor based on the current or target compressor flow rate.

8. The method of claim 7 further comprising:
creating, by the compressor controller, a pressure ratio array by interpolating between the multiple compressor pressure ratios corresponding to two of the plurality of compressor speeds based on the current or target compressor speed;
identifying, by the compressor controller, a current or target pressure ratio array location by identifying two of the multiple compressor pressure ratios of the pressure ratio array that are nearest to the current or target compressor pressure ratio and identifying a distance from the current or target compressor pressure ratio to at least one of the two of the multiple compressor pressure ratios; and
identifying, by the compressor controller, the current or target location in the operating condition matrix based on the current or target pressure ratio array location.

9. The method of claim 8 further comprising:
creating, by the compressor controller, a flow array by interpolating between the multiple compressor flow rates corresponding to the two of the plurality of compressor speeds based on the current or target compressor speed; and
determining, by the compressor controller, the current or target compressor flow rate by interpolating between two of the multiple compressor flow rates based on the current or target pressure ratio array location.

10. The method of claim 7 wherein the operating state matrix includes a second plurality of rows each corresponding to the one of the plurality of compressor speeds of the operating condition matrix, and a second plurality of columns each corresponding to the equally spaced locations along the plurality of compressor speeds between

Assignees

• Toyota Eng & Mfg North America

Inventors

• Farnsworth Jared

Classifications

• F02B33/40

  of non-positive-displacement type · CPC title

• F04D27/001

  Testing thereof; Determination or simulation of flow characteristics; Stall or surge detection, e.g. condition monitoring · CPC title

• F04D25/06

  the pump being electrically driven (F04D25/08 takes precedence) · CPC title

• F04D27/02 Primary

  Surge control {(surge detection F04D27/001)} · CPC title

• F02B2037/125

  Control for avoiding pump stall or surge · CPC title