Unipolar Motor Drive With Ring Fuel Cell for Smooth Vehicle Start-Up
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Solution Overview
Problem
Existing drive systems for motor vehicles using electric motors often experience irregularities in drive torque and radial/axial forces, leading to noise-vibration-harshness problems and weak start-ups, which are exacerbated by the need for high-voltage technology.
Innovation Solution
A drive system utilizing a unipolar machine with an integrated fuel cell that surrounds the rotor shaft, allowing for high current delivery at low voltages without the need for series connections, and incorporating a reformer to generate hydrogen from fuels like ammonia or methane, eliminating the requirement for high-voltage power electronics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional electric motors with commutation and power electronics are used, then high voltage operation is achieved, but torque irregularities and noise-vibration-harshness problems occur
Solution Approach 1:
The patent inverts the conventional approach by using a unipolar machine that operates at low voltage with high current instead of high voltage with commutation. The current flows in only one direction through the rotor windings, eliminating the need for commutation switches and power electronics, thereby removing the source of torque irregularities and NVH problems while maintaining power output through increased current intensity provided by the fuel cell.
2Power
If series connections of fuel cells are used to achieve high voltage, then voltage requirement is met, but device complexity increases
Solution Approach 1:
The patent changes the operating parameters of the fuel cell system by operating multiple fuel cells in parallel rather than in series. This maintains the voltage at low levels (suitable for unipolar machines) while increasing the current output capacity. The parallel configuration simplifies the system architecture, eliminates the need for complex series connection control, and directly matches the low-voltage high-current requirements of the unipolar motor.
3Power
If conventional electric motors are used, then high voltage operation is achieved, but start-up performance is weak
Solution Approach 1:
The patent inverts the conventional high-voltage approach by using low voltage with very high current from the fuel cell to drive the unipolar machine. This configuration provides excellent start-up torque because the unipolar machine can deliver high torque at low speeds without the commutation issues that plague conventional motors during start-up. The direct current flow and absence of switching elements enable smooth and powerful start-up performance.
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 eliminates torque irregularities and noise-vibration-harshness issues while enabling smooth start-ups, as the unipolar machine operates without commutation, and the fuel cell provides the necessary current intensity without high voltage, improving overall system efficiency and performance.
Implementation Method 1
The basic principle of a fuel cell is to supply hydrogen to one electrode of the fuel cell and oxygen to the other electrode. The hydrogen molecules are split at the electrode and give up electrons to the electrode, which flow over a conductor to the other electrode to form oxygen ions together in combination with the oxygen. Ultimately, water is produced and a current flows in the conductor between the electrodes.
Implementation Method 2
Electric current is conducted between the center of the disk and the edge of the disk. Due to the magnetic field, a Lorentz force on the moving charge carriers results, which leads to a torque on the disk.
Implementation Method 3
Hydrogen can be obtained from compounds such as methane or ammonia by reforming; the respective compound is split electrolytically during the process.
Data Source
AI summary
A drive system (1) having a unipolar machine (2) and a fuel cell (3) for supplying the unipolar machine (2) with electrical energy. The fuel cell (3) can be arranged in a ring shape around a rotor shaft (5) of a rotor (4) of the unipolar machine (2). The unipolar machine (2) can be provided in a motor vehicle (600) to supply a traction torque.