Control system for an electrically propelled traction vehicle

• US 5,432,413 A
• Filed: 10/22/1993
• Issued: 07/11/1995
• Est. Priority Date: 03/31/1992
• Status: Expired due to Term

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Beach, Frederick G., Chung, Wing Y., Grabowski, Francis M., Duke, Amy D.
• Primary Examiner(s): Ro, Bentsu
• Application Number:
  US08/147,234
• Time in Patent Office: 627 Days
• Field of Search: 318/139, 290/7, 290/8, 290/9, 290/10, 290/11, 290/14, 290/17, 290/21, 290/22, 290/24, 290/40 R, 290/40 A, 290/40 C, 290/45, 290/51, 180/65.2, 180/65.3, 180/65.4, 180/65.5
• US Class Current: 318/139
• CPC Class Codes: B60K 6/46 Series type
• CPC Class Codes: B60K 6/52 Driving a plurality of drive axles, e.g. four-wheel drive
• CPC Class Codes: B60L 15/2045 for optimising the use of energy
• CPC Class Codes: B60L 2240/445 Temperature
• CPC Class Codes: B60L 2270/44 Heat storages, e.g. for cabin heating
• CPC Class Codes: B60L 3/12 Recording operating variables ; Monitoring of operating variables
• CPC Class Codes: B60L 50/12 using AC generators and DC motors
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 2510/0676 Engine temperature
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility
• 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 10/72 Electric energy management in electromobility
• CPC Class Codes: Y10S 903/916 with plurality of drive axles

Abstract

A control system for an electrical propulsion system for a large wheeled vehicle adapted to haul a payload, the vehicle having an internal combustion engine and an electric generating means driven by the engine. The control system measures selected parameters and controls the engine and generating means to maximize output, and records historical operating data relating to the vehicle and its systems, and has a 2 digit display that provides information useful in troubleshooting problems. The control system also enhances fuel consumption by conserving fuel use, particularly on flat terrain and when the vehicle is approaching the overspeed point. Depression of the foot pedal is no longer input directly to the engine controller. Based on the amount of depression of the foot pedal, a fuel enhancement means determines the horsepower request from the operator of the foot pedal, but generates an engine rpm signal which will run the engine at only the rpm necessary to provide the power. The fuel enhancement means is further adapted to conserve fuel usage during periods of vehicle coast and electric brake by requiring minimum engine rpm to maintain sufficient cooling of vehicle equipment.

Claims

1. A control system for an electrical propulsion system for a wheeled vehicle adapted to haul a payload, the vehicle being equipped with a plurality of adjustable speed electric traction motors mechanically coupled in driving relation to separate wheels on the vehicle, the vehicle having an internal combustion engine and a foot pedal input for demanding horsepower from the internal combustion engine, the vehicle further having an electric generating means operatively connected to the engine and to the traction motors and providing electric power at its output for energizing the traction motors, the electric generating means being of the type which can vary the voltage and current of the electric power provided at its output responsive to control signals being applied thereto and having a first predetermined operating temperature of a component thereof that correlates to a rating at which continuous operation can occur without substantial risk of damage thereto, and a maximum predetermined operating temperature higher than the first predetermined operating temperature of the component during which continuous operation would create a substantial risk of damage to the electric generating means, said control system comprising:

processing means including memory means for controlling the operation of the internal combustion engine and the electric generating means;

means for measuring the ambient temperature of the environment in which the vehicle is operating and generating a signal indicative of said measured ambient temperature and applying the same to said processing means;

means for measuring the output voltage of the electric generating means and generating a signal indicative of said measured output voltage and applying the same to said processing means;

means for measuring the output current of the electric generating means and generating a signal indicative of said measured output current and applying the same to said processing means;

fuel enhancement means for determining the horsepower demand from the foot pedal input and generating a horsepower request signal to the processing means indicative of a rpm necessary to provide required power in a propel mode;

said processing means being adapted to generate control signals, including an engine rpm signal based on the horsepower request signal from the fuel enhancement means and apply the same to the vehicle engine to conserve fuel usage.

2. A system as defined in claim 1 wherein said electric generating means is adapted to vary the output voltage and output current to said traction motors to maintain a constant horsepower rating responsive to said control signals, said processing means being adapted to generate said control signals to said electric generating means to increase said output current and output voltage in proportion to maintain a constant horsepower rating when operating said electric generating means whereby the temperature of said component is above said first predetermined operating temperature.

3. A control system for an electrical propulsion system for a wheeled vehicle adapted to haul a payload, the vehicle being equipped with a plurality of adjustable speed electric traction motors mechanically coupled in driving relation to separate wheels on the vehicle, the vehicle having an internal combustion engine and a foot pedal input for demanding horsepower from the internal combustion engine, the vehicle further having an electric generating means operatively connected to the engine and to the traction motors and providing electric power at its output for energizing the traction motors, the electric generating means being of the type which can vary the voltage and current of the electric power provided at its output responsive to control signals being applied thereto and having a first predetermined operating temperature of a component thereof that correlates to a rating at which continuous operation can occur without substantial risk of damage thereto, and a maximum predetermined operating temperature higher than the first predetermined operating temperature of the component during which continuous operation would create a substantial risk of damage to the electric generating means, said control system comprising:

processing means including memory means for controlling the operation of the internal combustion engine and the electric generating means;

means for measuring the ambient temperature of the environment in which the vehicle is operating and generating a signal indicative of said measured ambient temperature and applying the same to said processing means;

means for measuring the output voltage of the electric generating means and generating a signal indicative of said measured output voltage and applying the same to said processing means;

means for measuring the output current of the electric generating means and generating a signal indicative of said measured output current and applying the same to said processing means;

fuel enhancement means for conserving fuel usage during periods of vehicle coast and electric brake;

said processing means being adapted to generate control signals, including a retard pedal depression signal from the fuel enhancement means for conserving fuel usage during the periods of vehicle coast and electric brake by requiring minimum engine rpm to maintain proper cooling of vehicle equipment, and also to apply the control signals to the electric generating means to increase the electric power provided at its output above the continuous rating and to generate and apply control signals to the electric generating means to return the same to the continuous rating responsive to a calculated simulated temperature reaching the maximum predetermined operating temperature of the component of the electric generating means.

4. A system as defined in claim 3 wherein said electric generating means is adapted to vary the output voltage and output current to said traction motors to maintain a constant horsepower rating responsive to said control signals, said processing means being adapted to generate said control signals to said electric generating means to increase said output current and output voltage in proportion to maintain a constant horsepower rating when operating said electric generating means whereby the temperature of said component is above said first predetermined operating temperature.

5. A control system for an electrical propulsion system for a wheeled vehicle adapted to haul a payload, the vehicle being equipped with a plurality of adjustable speed electric traction motors mechanically coupled in driving relation to separate wheels on the vehicle, the vehicle having an internal combustion engine and a foot pedal input operable by an operator for demanding horsepower from the internal combustion engine, the vehicle further having an electric generating means operatively connected to the engine and to the traction motors and providing electric power at its output for energizing the traction motors, the electric generating means being of the type which can vary the voltage and current of the electric power provided at its output responsive to control signals being applied thereto and having a first predetermined operating temperature of a component thereof that correlates to a rating at which continuous operation can occur without substantial risk of damage thereto, and a maximum predetermined operating temperature higher than the first predetermined operating temperature of the component during which continuous operation would create a substantial risk of damage to the electric generating means, said control system comprising:

processing means including memory means for controlling the operation of the internal combustion engine and the electric generating means;

means for measuring the ambient temperature of the environment in which the vehicle is operating and generating a signal indicative of said measured ambient temperature and applying the same to said processing means;

means for measuring the output voltage of the electric generating means and generating a signal indicative of said measured output voltage and applying the same to said processing means;

means for measuring the output current of the electric generating means and generating a signal indicative of said measured output current and applying the same to said processing means;

fuel enhancement means for determining the horsepower demand from the foot pedal input and generating a horsepower request signal to the processing means indicative of a rpm necessary to provide required power in a propel mode;

said processing means being adapted to generate control signals, including an engine rpm signal based on the horsepower request signal from the fuel enhancement means and apply the same to the vehicle engine to conserve fuel usage, and further including an engine rpm signal from the fuel enhancement means for conserving fuel usage during periods of vehicle coast and electric brake by requiring minimum engine rpm to maintain proper cooling of vehicle equipment, and also to apply the control signals to the electric generating means to increase the electric power provided at its output above the continuous rating and to generate and apply control signals to the electric generating means to return the same to the continuous rating responsive to a calculated simulated temperature reaching the maximum predetermined operating temperature of the component of the electric generating means.

6. A system as defined in claim 5 wherein said electric generating means is adapted to vary the output voltage and output current to said traction motors to maintain a constant horsepower rating responsive to said control signals, said processing means being adapted to generate said control signals to said electric generating means to increase said output current and output voltage in proportion to maintain a constant horsepower rating when operating said electric generating means whereby the temperature of said component is above said first predetermined operating temperature.