Variable Compression Ratio Control for Hybrid Regenerative Braking
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Solution Overview
Problem
Conventional hybrid vehicle systems using regenerative braking can cause discomfort to drivers and passengers due to rapid engine rotation when the internal combustion engine starts to consume surplus regenerative power after battery full charge, especially during long downward slopes.
Innovation Solution
A control method and device that utilizes an electric actuator of a variable compression ratio mechanism to consume surplus electric power by periodically changing the mechanical compression ratio of the internal combustion engine, masking any noise and maintaining a comfortable driving experience.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the internal combustion engine is driven rapidly to consume surplus regenerative electric power after battery full charge, then the surplus electric power is absorbed, but the driver and passenger experience uncomfortable mechanical noise and vibration
Solution Approach 1:
The patent replaces the conventional mechanical driving method (motoring the internal combustion engine) with an electrical actuation method (driving the variable compression ratio mechanism's electric actuator). This substitution eliminates the need for rapid engine rotation while still consuming surplus regenerative power, thereby avoiding the mechanical noise and vibration that cause driver discomfort.
Solution Approach 2:
The patent changes the operational parameter from engine rotation speed to compression ratio adjustment. Instead of consuming power through rapid engine rotation (high speed parameter), the system consumes power by adjusting the compression ratio through the electric actuator, which operates quietly and does not produce the harmful mechanical noise associated with rapid engine motoring.
2Object-affected harmful factors
If the internal combustion engine is kept stopped to maintain comfort during regenerative braking, then driver comfort is maintained, but surplus regenerative electric power cannot be consumed and battery overcharging occurs
Solution Approach 1:
The patent makes the variable compression ratio mechanism's electric actuator serve multiple functions: it not only adjusts the compression ratio for engine performance optimization but also acts as a power consumption load to absorb surplus regenerative electric power. This multi-functionality allows the system to maintain engine stoppage for comfort while simultaneously consuming excess power through the actuator.
Solution Approach 2:
The system uses its own variable compression ratio mechanism's electric actuator as the power consumption device, eliminating the need for external or additional components. The actuator serves the dual purpose of its primary function (compression ratio control) and the secondary function (power consumption during regenerative braking),实现ing self-service power management.
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
Effectively absorbs surplus regenerative power without causing discomfort, maintains engine efficiency, and reduces friction by warming engine components, thereby improving fuel efficiency and reducing battery overcharging.
Implementation Method 1
an electric actuator of a variable compression ratio mechanism
Data Source
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AI summary
A series hybrid vehicle is disclosed that comprises a power generation motor generator (1), a power generation internal combustion engine (2), a travel motor generator (4), a battery (5), and an inverter device (6). The internal combustion engine (2) has a variable compression ratio mechanism (12). When the travel motor generator (4) is performing regenerative braking operation, if the charge state (SOC) of the inverter device (6) is at or above a prescribed level (SOC1), an electric actuator (46) of the variable compression ratio mechanism (12) is operated to cause high/low variation of the mechanical compression ratio and consume excess regenerative power.