Dynamic Capacitor Bank for Energy Harvesting Voltage Stability

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Solution Overview

Problem

Energy harvesting devices, such as those using photovoltaic, thermoelectric, or piezoelectric elements, face significant fluctuations in electrical power output due to environmental conditions, requiring efficient storage and monitoring solutions to stabilize energy supply.

Innovation Solution

An electrical storage device configuration with a power generator, capacitors, and a control circuit that dynamically adjusts capacitance by connecting capacitors in parallel, using threshold voltages and switches to manage voltage fluctuations, allowing for high-speed charging and efficient energy storage while minimizing power consumption for monitoring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the capacitance value is increased to stabilize voltage fluctuations, then the voltage stability is improved, but the charging time increases and productivity decreases

Engineering Contradiction:
Improvevoltage stabilityVSAvoidcharging speed
Core Design Contradiction:
Stability of the object's compositionVSProductivity

Solution Approach 1:

The patent applies dynamics by making the capacitance value changeable rather than fixed. The capacitance is dynamically adjusted based on the charging state: during charging, a smaller capacitance value is used to enable fast charging; when charging is complete, a larger capacitance value is used to stabilize the voltage. This is achieved through a control circuit that switches between different capacitor configurations (single capacitor vs. multiple capacitors in parallel), resolving the contradiction between charging speed and voltage stability.

Inventive Principle:
Principle #15Dynamics

2Quantity of substance

If the capacitance value is increased to store more electrical energy, then the energy storage capacity is improved, but the power consumption for monitoring increases

Engineering Contradiction:
Improveelectrical energy storage capacityVSAvoidpower consumption for monitoring
Core Design Contradiction:
Quantity of substanceVSUse of energy by moving object

Solution Approach 1:

The patent applies self-service by using the generated electrical power itself to monitor the charging state. The control circuit automatically detects when the capacitor is fully charged by monitoring the voltage level, and this monitoring is performed using the power already being generated, without requiring additional external power sources. The system monitors its own state using the available power, eliminating the need for separate monitoring power supply.

Inventive Principle:
Principle #25Self-service

3Productivity

If the capacitance value is dynamically changed based on charging state, then the charging efficiency is improved, but the device complexity increases

Engineering Contradiction:
Improvecharging efficiencyVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the capacitance storage function into multiple separate capacitors that can be independently controlled. Instead of using one large capacitor with variable capacitance, the system uses multiple capacitors (e.g., C1, C2, C3) that can be connected in parallel or individually through switches (S1, S2, S3). This segmented approach allows the control circuit to selectively engage capacitors based on charging needs, achieving dynamic capacitance adjustment while maintaining relatively simple circuit implementation.

Inventive Principle:
Principle #1Segmentation

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 effectively stabilizes voltage fluctuations, reduces power consumption for monitoring, and simplifies the system, enabling efficient energy storage and use in energy harvesting applications.

Implementation Method 1

the electricity-generating elements are configured to temporarily store the electrical power in capacitance

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentUS10158240B2Electrical storage device and wireless system
Publication Date: 2018.12.18 KK TOSHIBA
  • US10158240B2 patent drawing
  • US10158240B2 patent drawing
  • US10158240B2 patent drawing

AI summary

An electrical storage device according to an embodiment includes a power generator; a first-type capacitor that stores the electrical power generated by the power generator; second-type capacitors that are connected to the first-type capacitor in parallel; switches each of which is connected to one of the second-type capacitors; and a control circuit that controls the switches. Every time either a charging voltage or an observation voltage proportional to the charging voltage exceeds a first threshold value, the control circuit controls the switches in such a way that the i+1-th second-type capacitor (where i is an integer equal to or greater than zero) is additionally connected to the first-type capacitor in parallel.