Voltage Adjustment for Energy Harvester Using Switch Module
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Solution Overview
Problem
Conventional energy harvesting devices face inefficiencies due to voltage drop during rectification and the need for additional inductance, which can result in output voltages outside the required range for autonomous devices like sensors, leading to operational issues.
Innovation Solution
An arrangement within the energy harvester that utilizes a switch module and controller to adjust AC voltage levels using inductance provided by a stator winding, allowing for selective operation modes to maintain or boost the output voltage within a predetermined range without additional inductance, thereby simplifying the system and enhancing efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a step-up converter is used to compensate for voltage drop due to diodes, then the output voltage can be maintained within the required range, but the device complexity increases due to additional inductance requirements
Solution Approach 1:
The pick-up coil serves dual functions: it generates the AC voltage through electromagnetic induction and simultaneously provides the inductance required for the step-up converter operation. This self-service approach eliminates the need for separate inductance components, reducing device complexity while maintaining output voltage stability within the 2-5V range required by autonomous devices
Solution Approach 2:
The pick-up coil is designed to perform multiple functions simultaneously: voltage generation through electromagnetic induction and inductance provision for the switching circuit. This multi-functionality resolves the contradiction by making the existing component serve the additional purpose of voltage regulation without adding extra components
2Ease of operation
If conventional rectification is used to convert AC voltage to DC voltage, then the voltage can be adjusted for autonomous devices, but efficiency is reduced due to voltage drop at diodes
Solution Approach 1:
The invention replaces conventional passive diode-based rectification with an active switching circuit controlled by a controller. This substitution eliminates the fixed voltage drop characteristics of diodes, allowing for efficient voltage regulation without the energy losses inherent in traditional rectification methods
Solution Approach 2:
The switching circuit dynamically adjusts the inductance utilization based on the instantaneous AC voltage magnitude. By controllably connecting and disconnecting the pick-up coil in synchronization with the AC voltage waveform, the system optimizes energy transfer and maintains high rectification efficiency while providing adjustable DC output voltage
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 reduces the complexity and cost of energy harvesting systems, increases efficiency, and ensures that the output voltage is within the required range for autonomous devices, preventing damage and ensuring reliable operation across varying input conditions.
Implementation Method 1
controlling, by the converter, a switch module to operate selectively in a first mode or a second mode depending on the input magnitude, in order to adjust the voltage to have an output magnitude in a predetermined range
Data Source
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AI summary
An arrangement (111,211) for voltage adjustment for an energy harvester (101,201) comprises: a first input terminal (131,231) and a second input terminal (133, 233) adapted to receive a AC voltage therebetween, the AC voltage having an input magnitude, the AC voltage being supplied at an inductance (107,207); a switch module (135,235) connected between the first input terminal (131,231) and the second input terminal (133,233) for controllably connecting the first input terminal with the second input terminal; and a controller (127) adapted to receive an input signal (129,229) indicative of the input magnitude of the voltage, and to control the switch module (135,235) to operate selectively in a first mode (121) or a second mode (125) depending on the input magnitude, in order to adjust the voltage to have an output magnitude in a predetermined range.