Electric Machine Independent Coil Control Segmentation
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Solution Overview
Problem
Existing electrical machines for motor vehicles, particularly electric bicycles, face limitations in flexibility and complexity due to the need for powerful and expensive power semiconductors to manage varying speed-torque characteristics, with current solutions either requiring complex cooling or limited to setting only one operating point.
Innovation Solution
The electrical machine features a stator arrangement with independently controlled coils on different teeth, magnetically coupled to allow opposite magnetic fluxes, and a higher-level control unit to manage these coils, along with a double stator design where each stator has its own coil arrangement and control unit, enabling independent control and reduced current requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a single control unit controls all stator coils to provide high torque, then the torque output is improved, but the power semiconductor complexity and cooling requirements increase significantly
Solution Approach 1:
The patent divides the single control unit into multiple independent control units, each controlling a subset of stator coils. This segmentation allows each control unit to operate at lower power levels, reducing the complexity and cost of power semiconductors while maintaining the ability to generate high torque through coordinated operation of all coils.
2Force
If powerful power semiconductors are used to control all coils for high torque, then the torque output is improved, but the cooling requirements and cost increase
Solution Approach 1:
By segmenting the control into multiple independent control units, each handling a portion of the total coil control, the power dissipation per control unit is reduced. This reduces the cooling requirements for each individual control unit, although the system as a whole still manages the same total power.
3Device complexity
If a single control unit is used to energize all stator coils, then the control structure is simplified, but the flexibility to set different operating points is limited
Solution Approach 1:
The patent segments the coil control into multiple independent control units, each capable of independently energizing its assigned coils. This independence enables flexible combination of different coil subsets to create various operating points and speed-torque characteristics, significantly enhancing adaptability.
Solution Approach 2:
The system dynamically reconfigures which coils are energized by different control units based on the desired operating point. This dynamic control allows the electric machine to adapt to different speed-torque requirements without mechanical transmission changes.
4Adaptability or versatility
If coils are controlled in multiple phases to provide different speed-torque characteristics, then the adaptability is improved, but the power semiconductor current requirements increase
Solution Approach 1:
Each control unit handles a subset of coils independently, so the current requirements are distributed across multiple lower-power control units rather than requiring a single high-current control unit. This segmentation enables multi-phase control for different speed-torque characteristics without proportionally increasing the power semiconductor current rating.
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 configuration allows for more flexible control of operating points, reduces the technical complexity and cost of control units, and eliminates the need for expensive rare-earth magnets, enabling efficient and flexible torque adjustment with reduced power semiconductor requirements.
Implementation Method 1
a plurality of coils (18), which are each independently controllable and magnetically coupled, and control units (20), each of which is assigned to a single coil (18) in order to supply the respective coils (18) independently with electric current to generate a magnetic field
Implementation Method 2
the coils (18) generate opposite magnetic fluxes, so that the individual magnetic fluxes, which together form the magnetic flux, are opposite and thus partially cancel each other out
Implementation Method 3
a rotor (14), which is rotatably mounted relative to the stator arrangement and capable of being driven in at least one direction of rotation by a magnetic field of the coils
Data Source
Figure 1a
Figure 1b
Figure 2a
AI summary
The invention relates to an electric machine (10; 30) for providing driving power, in particular for driving motor vehicles, comprising a stator assembly (12; 32, 34), which has a plurality of coils (18; 38, 42; 50, 52), a rotor (14; 44), which is supported so as to be rotatable in relation to the stator assembly (12; 32, 34) and which can be driven in at least one direction of rotation by a magnetic field of the coils (18; 38, 42; 50, 52), a plurality of control units (20; 46, 48; 54, 56), which are electrically connected to the coils (18; 38, 42) in order to control the coils (18; 38, 42; 50, 52) and in order to supply the coils with electric current in order to generate the magnetic field, wherein at least one of the control units (20; 46, 48; 54) is associated with an individual coil of the coils (18; 38, 42; 50) in order to control the individual coil (18; 38, 42) independently and in order to supply the individual coil with electric current independently.