Vibration Power Generator Impedance Control for Displacement Limiting
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Solution Overview
Problem
Vibration power generators face malfunctions due to excessive displacement amplitude of movable parts, which can collide with stationary parts, leading to inefficiencies in energy conversion from ambient vibrations to electric energy.
Innovation Solution
A power generation system that includes a vibration power generator, a rectifying and smoothing circuit, a converter, a displacement measuring part, a reference output part, a comparator, and a controller, which adjusts the duty ratio of the switching circuit to control the input impedance and prevent excessive displacement by increasing the braking force on the movable part when it reaches a reference displacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the displacement amplitude of the movable part is increased to harvest more energy from ambient vibration, then the energy conversion efficiency is improved, but the movable part may collide with the stationary part causing malfunction
Solution Approach 1:
The patent implements a feedback control mechanism where a displacement sensor continuously monitors the position of the movable part and feeds this information to a controller. The controller adjusts the electrical load on the generator in real-time based on the measured displacement, ensuring the movable part operates near its maximum safe displacement without colliding with stationary parts. This closed-loop feedback system resolves the contradiction by dynamically optimizing energy harvest while preventing collisions.
Solution Approach 2:
The patent dynamically adjusts the electrical load impedance presented to the vibration generator based on the real-time displacement amplitude. By varying the electrical damping characteristics through active load control, the system adapts to changing vibration conditions and displacement limits, maximizing energy extraction while maintaining safe operational boundaries and preventing mechanical contact between movable and stationary parts.
2Reliability
If the displacement amplitude is limited to prevent collisions, then system reliability is improved, but the energy harvesting efficiency decreases
Solution Approach 1:
The patent changes the electrical parameter (load impedance) dynamically to optimize energy harvesting at each operating point. By adjusting the electrical damping coefficient through variable load resistance and capacitance, the system maximizes the electrical energy extracted from the generator for each achievable displacement amplitude, ensuring optimal efficiency within the safe displacement limits defined by the mechanical constraints.
Solution Approach 2:
The system dynamically adapts the electrical load characteristics to match the instantaneous operating conditions. The controller continuously modifies the electrical damping based on the measured displacement amplitude and velocity, ensuring that the maximum possible energy is extracted from the generator at each moment while respecting the mechanical displacement constraints, thus resolving the efficiency-reliability tradeoff.
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
The system effectively suppresses excessive displacement amplitude, preventing collisions and ensuring stable energy conversion from ambient vibrations to electric power, thereby enhancing the reliability and efficiency of vibration-based power generation.
Implementation Method 1
A vibration power generator converts the kinetic energy from ambient vibration into electric energy
Implementation Method 2
a converter (30) including a switching circuit, which has a duty ratio, that converts an output voltage of the rectifying and smoothing circuit (20)
Implementation Method 3
increasing the braking force on the movable part when it reaches a reference displacement
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
According to one embodiment, a power generation system includes a power generator, a displacement measuring part, and a converter. The power generator includes a movable part and converts mechanical energy of the movable part into electric power. The displacement measuring part measures a displacement of the movable part. The converter includes a switching circuit whose duty ratio is controlled based on the measured displacement, and converts a voltage level of the electric power.