Hybrid Powertrain Voltage Control for Real-Time Loss Reduction
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Solution Overview
Problem
Existing methods for determining the optimal supply voltage for hybrid motor vehicles with multiple electrical machines are complex and time-consuming, especially in real traffic conditions, leading to inefficiencies in electrical losses and fuel consumption.
Innovation Solution
An analytical method is developed to calculate the optimal supply voltage using a mathematical expression that minimizes electrical losses, allowing for precise control of the voltage modulation device, which requires low computing power and ensures continuous operation, thereby optimizing performance across various driving situations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a map-based method is used to determine optimal supply voltage, then the voltage can be optimized for electrical machines, but the calculation becomes complex and time-consuming especially with multiple electrical machines
Solution Approach 1:
The patent transforms the complex multi-dimensional map lookup problem into a simplified analytical calculation by changing the mathematical parameters. Instead of navigating complex multi-dimensional maps with multiple electrical machine variables, the invention uses a quadratic function of supply voltage that can be solved analytically, reducing computational complexity while maintaining optimization accuracy
Solution Approach 2:
The patent extracts the essential relationship between supply voltage and electrical losses from the complex multi-machine system. By identifying that electrical losses can be expressed as a quadratic function of supply voltage (Pbat = a*Ue² + b*Ue + c), the invention separates the critical optimization variable (supply voltage) from other system complexities, enabling straightforward analytical solution
2Loss of energy
If a map-based method is used to determine optimal supply voltage, then voltage optimization is possible, but the implementation time increases which is problematic for real traffic conditions
Solution Approach 1:
The patent replaces the mechanical/map-based lookup system with an analytical mathematical system. Instead of reading from pre-generated multi-dimensional maps that require complex navigation and interpolation, the invention substitutes this with direct analytical calculation using quadratic function resolution, dramatically reducing computation time for real-time control
Solution Approach 2:
The patent performs preliminary formulation of the electrical losses as a quadratic function of supply voltage, preparing the mathematical model in advance. This allows the optimal voltage to be calculated directly through analytical resolution of the quadratic equation, eliminating the need for time-consuming real-time map generation or complex iterative searches
Data Source
AI summary
Disclosed is a method for controlling a hybrid vehicle power train, including a thermal drive chain and an electric drive chain, the electric drive chain including a traction battery, a voltage modulator, an inverter, first and second electrical machines. The voltage modulator is designed to modulate a supply voltage of an electric current from the traction battery to the first and second electrical machines. The method includes: a step of analytically calculating an optimal supply voltage using a mathematical expression that corresponds to the resolution of an equation expressed as∂Pbat∂Ue=0,where Ue is the supply voltage, Pbat is the electrical power supplied by the traction battery, and where the electrical power supplied by the traction battery is expressed as a quadratic function of the supply voltage; and a step of controlling the voltage modulator in such a way that it outputs the optimal supply voltage.