Optimization of extended range electric vehicle

• US 9,211,804 B2
• Filed: 11/10/2014
• Issued: 12/15/2015
• Est. Priority Date: 12/18/2012
• Status: Expired due to Fees

• Current Assignee: Emerald Automotive LLC (Zhejiang Geely Holding Group Co., Ltd.)
• Original Assignee: Emerald Automotive LLC (Zhejiang Geely Holding Group Co., Ltd.)
• Inventors: Preece, Andrew
• Primary Examiner(s): BUTLER, RODNEY ALLEN
• Application Number:
  US14/537,632
• Publication Number:
  US 20150134174A1
• Time in Patent Office: 400 Days
• US Class Current: 1/1
• CPC Class Codes: B60L 2260/50 by future state prediction
• CPC Class Codes: B60L 2260/52 drive range estimation, e.g. of estimation of available travel distance
• CPC Class Codes: B60L 2260/54 Energy consumption estimation
• CPC Class Codes: B60L 50/62 charged by low-power generators primarily intended to support the batteries, e.g. range extenders
• CPC Class Codes: B60L 58/13 Maintaining the SoC within a determined range
• CPC Class Codes: H01M 10/44 Methods for charging or discharging circuits for charging H02J7/00
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage
• CPC Class Codes: H02J 7/1446 in response to parameters of a vehicle
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/92 Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles

Abstract

Disclosed is a computer-implemented method and system for operating an auxiliary power unit (APU) in a range-extended electric vehicle between a minimum state of charge (SoC) limit and a maximum SoC limit of the battery pack, including predicting expected energy use profile of said vehicle; predicting change in SoC for both “APU off” and “APU on” states at a predetermined power setting corresponding to the desired optimal point (for example, the most efficient, or most powerful, or most comfortable, or lowest noise) for the specific vehicle and APU type in question; setting SoC limits for said battery pack at end of journey to minimum acceptable values based on the design and characteristics of the battery pack; and, working iteratively in reverse order from the end of journey, using “APU on” SoC values to set the minimum-limit of SoC, and “APU off” value to set the maximum-limit of SoC.

Claims

1. A computer-implemented method for operating an auxiliary power unit (APU) in an extended-range electric vehicle (EREV) between a minimum state of charge (SoC) limit and a maximum SoC limit of a battery pack, the method comprising:

predicting expected energy use profile of a vehicle;

predicting change in SoC for both “

APU off” and

“

APU on”

states at a predetermined power setting corresponding to the desired optimal point for the specific vehicle and APU type in question;

setting SoC limits for said battery pack at end of a journey to minimum acceptable values based on the design and characteristics of the battery pack; and

,

working iteratively in reverse order from the end of the journey, using “

APU on”

SoC values to set the minimum-limit of SoC, and “

APU off”

value to set the maximum-limit of SoC;

wherein said predicting expected energy use profile of the vehicle is determined by calculating the maximum possible range in electric vehicle (EV) mode along a proscribed route;

wherein said predicting expected energy use assumes a substantially constant rate of acceleration and substantial adherence to speed limits.

2. The method of claim 1 wherein said predicting expected energy use places a value on the gradient of road segments and the internal losses of a drive-train.

3. A computer-implemented method for operating an auxiliary power unit (APU) in an extended-range electric vehicle (EREV) between a minimum state of charge (SoC) limit and a maximum SoC limit of a battery pack, the method comprising:

predicting expected energy use profile of a vehicle;

predicting change in SoC for both “

APU off” and

“

APU on”

states at a predetermined power setting corresponding to the desired optimal point for the specific vehicle and APU type in question;

setting SoC limits for said battery pack at end of a journey to minimum acceptable values based on the design and characteristics of the battery pack; and

,

working iteratively in reverse order from the end of the journey, using “

APU on”

SoC values to set the minimum-limit of SoC, and “

APU off”

value to set the maximum-limit of SoC;

wherein said predicting expected energy use profile of the vehicle is determined via the vehicle'"'"'s sensor data, GPS data, and the map data from the proscribed route;

wherein said predicting expected energy use profile of the vehicle is determined according to the following algorithm;

estimate Vehicle Tractive Power (VP) from Traction Force×

Vehicle Speed;

wherein said Traction Force is the force to overcome the combined effects of;

a) the aerodynamic drag, Fa equal to one half times the density of air times the coefficient of drag times the exposed frontal area times the vehicle'"'"'s velocity squared;

b) the rolling resistance, Fr equal to the coefficient of rolling resistance times the download force or weight over the wheels;

c) the gradient of the road, Fa equal to the total mass of the vehicle times the gravitational force times the incline angle in radians; and

,

d) the vehicle'"'"'s inertial resistance, Fi equal to the total mass of the vehicle times the vehicle'"'"'s acceleration.

4. A computer-implemented method for operating an auxiliary power unit (APU) in an extended-range electric vehicle (EREV) between a minimum state of charge (SoC) limit and a maximum SoC limit of a battery pack the method comprising:

predicting expected energy use profile of a vehicle;

predicting change in SoC for both “

APU off” and

“

APU on”

states at a predetermined power setting corresponding to the desired optimal point for the specific vehicle and APU type in question;

setting SoC limits for said battery pack at end of a journey to minimum acceptable values based on the design and characteristics of the battery pack; and

,

working iteratively in reverse order from the end of the journey, using “

APU on”

SOC values to set the minimum-limit of SoC, and “

APU off”

value to set the maximum-limit of SoC;

wherein said predicting change in SoC for both “

APU off” and

“

APU on”

at preferred power setting is accomplished with reference to the predicted energy use and energy inputs from regenerative braking.

5. A computer-implemented method for operating an EREV to provide adequate SoC to minimize use of an Auxiliary Power Unit (APU) and flexible to complete a journey with the SoC being at a predefined level when an end target is obtained, the method comprising:

a vehicle control unit (VCU) in an EREV turns on an APU if battery SoC is at or below a minimum limit and turns off the APU if the SOC is at or above maximum limit to provide for the energy requirements of the EREV;

during the journey, applying a decisioning process to dynamically predict expected energy requirements of the EREV defining an operating envelope SoC wherein predicted energy use profile of the vehicle takes account of at least a zero emission on route and performs the decisioning assuming the APU is not run in the zone;

based on a prediction of energy demand for each driving as the EREV approaches the end of journey the maximum and minimum SoC limits become closer until at the end the maximum and minimum SoC limits are at the same level; and

,

SoC limits are determined by predicting change in SoC for both “

APU off” and

“

APU on”

from predicted energy use and energy inputs from regenerative braking.