Hybrid Vehicle Voltage Modulation for Continuous Loss Minimization
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Solution Overview
Problem
Existing methods for controlling the supply voltage of electric machines in hybrid vehicles are not effective due to coarse discretization, resulting in suboptimal electrical losses and fuel consumption.
Innovation Solution
An analytical method is proposed to calculate the optimal supply voltage based on the optimal electric torque and speed of the electric machine, minimizing electrical losses in the modulation device and electric machine.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If discretization method is used to determine optimal supply voltage, then implementation is simplified, but voltage precision is insufficient
Solution Approach 1:
The patent changes the parameter representation from discrete voltage levels to continuous analytical expressions. By expressing optimal supply voltage as a function of operating parameters (torque, speed, equivalence factor) rather than using fixed discrete levels, the system achieves both precision and computational efficiency.
2Measurement precision
If analytical calculation method is used to determine optimal supply voltage, then voltage precision is improved, but computing power requirement increases
Solution Approach 1:
The patent extracts the computational complexity from real-time optimization and moves it to pre-calculated analytical expressions. By deriving closed-form solutions for optimal voltage based on operating parameters, the system eliminates the need for complex real-time computations while maintaining high precision.
3Device complexity
If discrete voltage levels are used, then device complexity is reduced, but electrical losses increase
Solution Approach 1:
The patent transitions from static discrete voltage levels to dynamic continuous voltage optimization. By calculating optimal supply voltage as a continuous function of operating conditions (torque, speed, equivalence factor), the system adapts voltage in real-time to minimize electrical losses without increasing device complexity.
Data Source
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AI summary
The invention relates to a method for controlling a device (33) for modulating a power supply voltage (Ue) of an electrical current that is drained by a traction battery (31) of a motor vehicle (1) and that is supplied to an electrical machine (36) of the motor vehicle. According to the invention, the method comprises: - a step of computing an optimal electrical torque that the electrical machine has to develop, on the basis of an energy value (Pr) required to propel the motor vehicle and on an equivalence factor associated with the traction battery; - a step of analytically computing an optimal power supply voltage on the basis of said optimal electrical torque and of the rate of the electrical machine, said optimal electrical voltage minimising the electrical losses in an assembly (32) comprising at least the modulation device and the electrical machine; and - a step of controlling said modulation device so that it delivers said optimal power supply voltage.