Adjustable Rotor Flux Synchronous Machine for Wide Speed Range
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Solution Overview
Problem
Conventional synchronous machines are limited in their ability to cover a wide speed range while maintaining high torque, as the constant rotor flux fixes the system at a specific nominal operating point, leading to reduced drive power at higher speeds.
Innovation Solution
The design incorporates a dual rotor section with movable magnetic flux generating means, allowing for mechanical variation of rotor flux by changing the relative position of the rotor sections, enabling high torque at low speeds and high speeds with reduced flux, thus expanding the usable speed range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the rotor flux is increased to achieve high torque, then the maximum torque is improved, but the speed range is limited and the system is fixed at a specific nominal operating point
Solution Approach 1:
The rotor flux is made dynamically adjustable through a field weakening mechanism that can reduce the flux magnitude. The magnetic flux generating means includes adjustable components (such as controllable permanent magnets or electromagnets) that allow the rotor flux to be varied from a high value for torque production to a lower value for high-speed operation, enabling the system to adapt to different operating conditions rather than being fixed at a single nominal point
Solution Approach 2:
The invention changes the parameter of rotor flux magnitude to resolve the contradiction. By implementing field weakening that reduces the rotor flux from its maximum value, the system can operate at higher speeds while maintaining controllability. This parameter change allows the same machine to deliver high torque at low speeds and high speed performance when needed
2Speed
If the rotor flux is reduced to enable higher speeds, then the speed range is improved, but the maximum torque is reduced
Solution Approach 1:
The system employs dynamic control of the rotor flux through field weakening mechanisms that can adjust the flux magnitude in real-time. This allows the synchronous machine to operate with high rotor flux for maximum torque applications and switch to reduced flux for high-speed operations, providing adaptability across different operating regimes rather than being constrained to a fixed flux level
Solution Approach 2:
The invention utilizes parameter changes in the rotor flux magnitude to enable high-speed operation. By reducing the rotor flux through field weakening, the system can extend its speed range beyond the base speed while maintaining stable operation. The same adjustable flux system can then increase the flux back to maximum levels when high torque is required
3Ease of operation
If the system is fixed at a specific nominal operating point with constant rotor flux, then the control is simplified, but the adaptability to different speed and torque requirements is reduced
Solution Approach 1:
The invention implements dynamic field weakening control that allows the rotor flux to be adjusted from its nominal value to reduced levels. This dynamic capability enables the synchronous machine to adapt to varying speed and torque requirements while maintaining a relatively simple control structure based on conventional power electronics and control algorithms, thus achieving versatility without excessive complexity
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 design allows the synchronous machine to operate efficiently across a large speed range with high torque capabilities, optimizing performance by mechanically adjusting the rotor flux without the need for additional energy supply beyond the initial adjustment.
Implementation Method 1
the rotor has a first rotor section with first magnetic flux generating means (22) for generating a rotor flux (36), with which the rotating field (38) interacts
Implementation Method 2
The rotor flux generated by the magnetic flux generation means of the first rotor section can be influenced by the magnetic flux influencing means such that the total rotor flux provided by the rotor is different in size in the two relative positions
Data Source
Figure 1~2
Figure 3a~4b
Figure 5~6
AI summary
An electrical synchronous machine (10) is proposed, in particular for use as a drive device in technical motor vehicle applications, with a stator (12) that has an electrical winding arrangement (14) to generate a rotating field (38), and with a rotor (16) that has magnetic flux generators (22, 26) to generate a rotor flux (36) with which the rotating field (38) interacts. The rotor (16) has a first rotor segment (24) with first magnetic flux generators (22) and a second rotor segment (18) with magnetic flux controllers (26), wherein the two rotor segments (24, 18) can be moved relative to one another between at least a first and a second relative position (91, 92) in such a way that the rotor flux (36) provided by the rotor (16) is of different magnitudes in the two relative positions (91, 92).