Rotating Electric Machine Dynamic Excitation Control
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Solution Overview
Problem
The existing rotating electrical machines in motor vehicles are oversized due to the need to supply maximum current, which exceeds average consumption, leading to inefficiency and unnecessary thermal stress.
Innovation Solution
The machine is controlled to vary the excitation current based on a maximum excitation current map and thermal protection, allowing it to operate in extended generator modes to supply higher currents while ensuring thermal safety, thus enabling the use of smaller machines that can match top-class performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the rotating electrical machine is sized to supply maximum current continuously, then the maximum current capability is improved, but the machine size and weight increase
Solution Approach 1:
The patent applies dynamics by making the excitation current adjustable and variable over time. The control device dynamically modifies the excitation current based on thermal conditions and power demands, allowing the machine to operate at different power levels. This enables a smaller machine to achieve top-class maximum current capability temporarily when needed, rather than being continuously oversized.
Solution Approach 2:
The patent changes the excitation current parameter based on thermal protection conditions and power demands. By varying the excitation current within defined limits (using a maximum excitation current map as a function of rotor speed), the machine can temporarily deliver higher currents without requiring permanent oversizing, thus reducing machine size while maintaining peak performance capability.
2Power
If the rotating electrical machine operates in extended generator mode with higher currents, then the current output is improved, but thermal stress increases
Solution Approach 1:
The patent implements feedback through the control device that continuously monitors thermal conditions and adjusts the excitation current accordingly. The thermal protection module provides feedback about temperature status, and the control device uses this information to modify the excitation current in real-time, allowing extended generator mode operation when thermal conditions permit while preventing excessive thermal stress.
Solution Approach 2:
The excitation current is made dynamic and adjustable based on real-time thermal conditions. The control device can temporarily increase the excitation current beyond nominal levels when thermal protection conditions are met, enabling higher current output during extended generator mode without causing dangerous thermal stress accumulation.
3Power
If the rotating electrical machine is oversized for average consumption, then the maximum current capability is improved, but the efficiency during average operation deteriorates
Solution Approach 1:
The patent makes the machine operation dynamic by allowing the excitation current to be adjusted according to actual power demands. During average consumption periods, the machine operates at lower excitation current levels, improving efficiency. When peak demand occurs, the excitation current can be increased to provide maximum current capability, eliminating the need for permanent oversizing.
Solution Approach 2:
The excitation current parameter is changed based on operational conditions. By using a maximum excitation current map and thermal protection conditions, the system optimizes the excitation current for each operating scenario, improving efficiency during average operation while maintaining the ability to deliver maximum current when needed.
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
This solution allows the machine to supply higher currents when needed, optimizing size and efficiency by operating within thermal limits, reducing the need for oversized machines and enhancing performance during peak demand.
Implementation Method 1
the machine makes it possible to transform a rotational movement of the rotor driven by the heat engine of the vehicle, into an electric current induced in the phases of the stator
Implementation Method 2
A rectifier bridge connected to the phases of the stator makes it possible to rectify the sinusoidal induced current into a direct current
Data Source
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AI summary
The present invention concerns a rotating electrical machine for a motor vehicle. The machine (1) comprises a rotor (2) supplied with an excitation current (ie), a stator (3) comprising a polyphase winding and coupled to the rotor (2), a thermal protection module (4) suitable for evaluating at least one temperature (T1, T2, T3) in the machine and for comparing said temperature with an associated thermal protection threshold (Th), a control device (5) supplying the excitation current (ie) depending on an operation mode command (RQ) and said temperature comparison, so as to operate the rotating electrical machine (1) according to a mode of operation chosen from a nominal generator mode in which the machine is configured to deliver a first maximum power or at least one extended generator mode in which the machine is configured to deliver a second maximum power greater than said first maximum power.