EV Powertrain Low-SOC Control for Range Extension
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Solution Overview
Problem
Electric vehicles face challenges in maintaining performance when the battery is at a low state of charge, as energy consumption by the traction motor becomes a significant concern, making it difficult to extend the vehicle's range.
Innovation Solution
A control system is implemented to detect a low state of charge and operate the powertrain in a low state of charge mode, where parameters such as traction motor torque, cooling systems, and accessory power consumption are adjusted to reduce power drawn from the battery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the traction motor operates at normal power levels to maintain vehicle performance, then vehicle performance is maintained, but the battery depletes faster and range is reduced at low state of charge
Solution Approach 1:
The control system dynamically adjusts powertrain parameters including traction motor torque, cooling system operation, and accessory power consumption based on real-time state of charge detection. When low SOC is detected, the system transitions to a low SOC mode that reduces overall power consumption while maintaining essential vehicle functions, thereby extending range without completely sacrificing performance
Solution Approach 2:
The system changes operating parameters of the powertrain components when low state of charge is detected. This includes adjusting traction motor torque curves, modifying cooling system operational parameters, and reducing accessory power consumption. These parameter changes optimize the balance between maintaining vehicle performance and reducing battery power consumption to extend range
2Use of energy by moving object
If the traction motor torque is reduced to save energy at low state of charge, then power consumption is reduced and range is extended, but vehicle performance is compromised
Solution Approach 1:
The system applies partial torque reduction rather than complete power cutoff when low SOC is detected. By carefully controlling the degree of torque reduction and selectively managing which accessories and cooling functions are maintained versus reduced, the system achieves energy savings while preserving sufficient traction motor power for essential vehicle operation and performance needs
Data Source
AI summary
A control system for controlling a powertrain of an electric vehicle is disclosed. The powertrain comprises a traction motor and a battery for powering the traction motor. The control system is configured to detect a low state of charge of the battery and to operate the powertrain in a low state of charge mode when the low state of charge is detected. In the low state of charge mode, the control system adjusts at least one parameter of the powertrain, such as traction motor torque, powertrain cooling, accessory cooling and accessory power consumption, to reduce power drawn from the battery.