EV Controller Dynamic Discharge Limit for Battery Range
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Solution Overview
Problem
Electric vehicles face challenges in managing battery state of charge to prevent damage from overcharging or deep discharging, leading to limited operational ranges and potential battery degradation.
Innovation Solution
A vehicle system that includes a controller configured to receive vehicle speed and battery state of charge inputs, disabling drive torque and enabling regenerative braking when the battery state of charge falls below a predetermined limit, thereby extending the battery range by controlling shutdown and providing energy for electric braking and steering assistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the battery is maintained within a strict operating range (20%-80% BSOC) to prevent damage, then battery reliability is improved, but the vehicle operational range is reduced
Solution Approach 1:
The patent applies dynamics by transitioning from a static, fixed discharge limit (20% BSOC) to a dynamic, adaptive discharge limit that changes based on real-time vehicle conditions. The controller adjusts the discharge limit threshold based on factors such as vehicle speed, braking intensity, and regenerative braking capability, allowing the battery to operate safely below the traditional 20% limit when conditions permit, thereby extending vehicle range while maintaining battery reliability.
Solution Approach 2:
The patent changes the parameter of discharge limit threshold from a fixed value (20% BSOC) to a variable value that adapts to operating conditions. By modifying this critical parameter dynamically, the system enables the battery to discharge to lower levels (below 20% BSOC) when regenerative braking can recover energy, thus extending operational range without compromising battery health.
2Use of energy by moving object
If regenerative braking is activated at low BSOC levels, then energy recovery is improved, but battery damage risk increases
Solution Approach 1:
The patent implements feedback control by continuously monitoring battery state of charge, vehicle speed, braking intensity, and regenerative braking effectiveness. The controller uses this feedback to dynamically adjust the discharge limit and regulate regenerative braking activation, ensuring that energy recovery occurs only when it will not compromise battery safety. This closed-loop control enables safe operation below traditional discharge limits.
Solution Approach 2:
The system dynamically adjusts the discharge limit threshold based on real-time conditions such as vehicle speed and braking intensity. When vehicle speed and braking intensity indicate strong regenerative braking potential, the system allows discharge below 20% BSOC to maximize energy recovery. When conditions are unfavorable for regenerative braking, the system maintains higher discharge limits to protect battery safety.
3Reliability
If drive torque is disabled at low BSOC to protect the battery, then battery reliability is improved, but vehicle propulsion capability is reduced
Solution Approach 1:
The patent dynamically adjusts the discharge limit threshold based on real-time vehicle conditions including vehicle speed, braking intensity, and regenerative braking capability. When conditions favor energy recovery (higher vehicle speed, stronger braking), the system allows discharge below 20% BSOC and maintains drive torque availability, thus preserving propulsion capability while protecting the battery through conditional operation.
4Duration of action of moving object
If the discharge limit is lowered to extend battery range, then vehicle operational range is improved, but battery damage risk increases
Solution Approach 1:
The patent applies dynamics by transitioning from a static discharge limit (20% BSOC) to a dynamic, adaptive discharge limit that changes based on real-time vehicle conditions. The controller adjusts the discharge limit threshold based on factors such as vehicle speed, braking intensity, and regenerative braking capability, allowing the battery to operate safely below the traditional 20% limit when conditions permit, thereby extending vehicle range while maintaining battery reliability.
Solution Approach 2:
The patent changes the parameter of discharge limit threshold from a fixed value (20% BSOC) to a variable value that adapts to operating conditions. By modifying this critical parameter dynamically, the system enables the battery to discharge to lower levels (below 20% BSOC) when regenerative braking can recover energy, thus extending operational range without compromising battery health.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system allows electric vehicles to operate below the discharge limit, extending the battery range and preventing damage by disabling propulsion systems and activating regenerative braking, which provides energy for essential functions during low battery levels.
Implementation Method 1
a motor configured to provide drive torque and to facilitate regenerative braking
Implementation Method 2
a motor configured to provide drive torque and to facilitate regenerative braking
Data Source
AI summary
A vehicle is provided with a motor that is configured to provide drive torque and to facilitate regenerative braking. The vehicle also includes a controller that is configured to receive input that is indicative of a vehicle speed and a battery state of charge (BSOC), and to disable the drive torque when the BSOC is less than a maximum discharge limit. The controller is also configured to activate regenerative braking when the BSOC is less than the maximum discharge limit and the vehicle speed is greater than a predetermined speed.