Rotor Position Switching in Permanent Magnet Generators
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Solution Overview
Problem
Existing power generators with cylindrical rotors and stators experience electromagnetic resistance that opposes the rotational direction, leading to reduced power generation efficiency.
Innovation Solution
A power generator with a cylindrical rotor and stator, equipped with a rotational position detection unit and control unit, controls switching elements to turn off during periods of opposing electromagnetic resistance and turn on during other periods to align current flow with the rotational direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a permanent magnet passes directly above the stator coil during rotor rotation, then electromagnetic induction generates induced current in the coil, but electromagnetic resistance occurs in the direction opposite to the rotational direction, deteriorating power generation efficiency
Solution Approach 1:
The patent applies dynamics by making the switching element's state variable (on/off) change dynamically based on the rotor's rotational position. The control unit adjusts the switching element's conduction state in real-time as the rotor rotates, allowing the system to adapt to changing electromagnetic conditions and eliminate harmful electromagnetic resistance while maintaining beneficial induced current generation.
Solution Approach 2:
The patent implements periodic action by controlling the switching element to turn on and off at specific periodic intervals corresponding to the rotor's rotation cycle. The control unit detects the rotational position and activates the switching element during specific phases of the rotation period, creating a periodic control pattern that synchronizes with the rotor's motion to prevent electromagnetic resistance.
2Object-generated harmful factors
If a switching element is introduced to control induced current flow, then electromagnetic resistance can be reduced, but the device complexity increases due to additional control components
Solution Approach 1:
The patent applies feedback by using the rotational position detection unit to provide real-time information about the rotor's position to the control unit. This feedback loop allows the control unit to make informed decisions about when to activate or deactivate the switching element, ensuring that control actions are precisely timed to eliminate electromagnetic resistance without requiring overly complex control logic.
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
Reduces electromagnetic resistance, allowing the rotor to rotate more efficiently by controlling current direction, thereby enhancing power generation efficiency.
Implementation Method 1
a rotational position detection unit that detects a rotational position of the rotor
Implementation Method 2
generates a voltage by rotating the rotor... a change in a magnetic flux passing through a coil generates an electromotive force (voltage) in the coil
Implementation Method 3
the magnetic flux penetrating the coil increases... a new magnetic flux is generated
Data Source
AI summary
In a power generator that generates electricity by utilizing electromagnetic induction between a plurality of permanent magnets provided in a rotor and a plurality of coils which are provided in a stator arranged concentrically with the rotor. The power generator includes a rotational position detection unit 11 that detects a rotational position of the rotor, first switching elements Tr11 and Tr12 provided on a first path through which an induced current generated in a coil 32 flows, and a control unit 12 that controls the first switching elements Tr11 and Tr12 to be turned off in a first period that is at least part of a period in which electromagnetic resistance is generated in a direction opposite to a rotational direction of the rotor due to flowing of the induced current, and controls the first switching elements Tr11 and Tr12 to be turned on in a period other than the first period. During the first period in which electromagnetic resistance is generated when the induced current flows, the induced current in a direction in which the electromagnetic resistance is induced is not allowed to flow on the first path.