Rotary Electric Machine Gap Portions Magnetic Saturation
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Solution Overview
Problem
Interior permanent magnet synchronous motors experience decreased torque in low-current states due to high motor losses, and existing technologies lack a defined relationship between permanent magnets and air gaps to optimize efficiency.
Innovation Solution
Forming gap portions around permanent magnets with a predetermined shape and size to cause magnetic saturation at low currents, reducing magnetic flux and iron losses, while avoiding saturation at high currents to maintain maximum torque, thereby optimizing the relationship between gap portions and permanent magnets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If gap portions are formed around permanent magnets to reduce magnetic flux and iron losses, then motor losses are reduced in low-current state, but torque decreases in low-current state
Solution Approach 1:
The gap length is precisely controlled to fall within 0.5-2.0mm to change the magnetic circuit parameters. This parameter optimization allows the gap to reduce magnetic flux and iron losses while maintaining sufficient torque by preventing excessive flux reduction that would occur with larger gaps.
Solution Approach 2:
Gap portions are formed only at specific locations around the permanent magnets rather than uniformly throughout the rotor. This localized modification reduces magnetic flux in critical areas to decrease iron losses while preserving torque-generating regions, achieving energy loss reduction without significant torque penalty.
2Loss of energy
If gap portions are formed to weaken magnetic flux and reduce iron loss, then operating efficiency improves in low-current state, but maximum torque may decrease in high-current state
Solution Approach 1:
The gap length parameter is optimized to 0.5-2.0mm to achieve the right balance: long enough to reduce magnetic flux density and iron losses, but short enough to prevent excessive flux weakening that would compromise maximum torque capability in high-current operating conditions.
Solution Approach 2:
Instead of forming large gaps that would excessively reduce flux, the invention uses partially sized gaps (0.5-2.0mm) that provide sufficient flux reduction to lower iron losses while maintaining enough magnetic flux to preserve maximum torque output when high current is supplied.
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 reduces motor losses and maintains torque in low-current states, enhancing the operating efficiency of the rotary electric machine without decreasing maximum torque in high-current states.
Implementation Method 1
the gap portions are formed to have such a predetermined length that causes magnetic saturation during generation of low torque in a low-current state and that causes no magnetic saturation during generation of maximum torque in a high-current state
Data Source
AI summary
A rotary electric machine configured with a stator, rotor, and permanent magnets disposed in an inverted V-shape that becomes gradually narrower from a side of a center of rotation of the rotor. The rotor is provided with a plurality of support portions that extend radially about the center of rotation, and gap portions are respectively formed in correspondence with the plurality of support portions at positions spaced by a predetermined distance from an edge portion of the permanent magnets in a flowing direction of magnetic flux between the permanent magnets and the stator. The gap portions are formed to have such a length that causes magnetic saturation during generation of low torque in a low-current state and that causes no magnetic saturation during generation of maximum torque in a high-current state in which electricity at a high current is supplied to the stator coil.