Supercapacitor Charging Circuit with Dynamic Mode Switching

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Solution Overview

Problem

Conventional charging methods for supercapacitors face inefficiencies, such as low efficiency and long charging times in constant voltage charging, complexity in constant power charging, and potential damage from complete discharge, while existing methods do not account for the unique charging capabilities of supercapacitors which can start charging from zero voltage.

Innovation Solution

A charging circuitry comprising a power electronic converter, current sensor, voltage boost/buck controller, and charging mode controller that generates feedback signals to manage charging modes, including constant power and voltage modes, to optimize charging efficiency and prevent inrush currents by using sensed voltages and currents to control the charging process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If constant current charging is used, then charging efficiency is improved, but energy storage capacity is affected due to large voltage difference

Engineering Contradiction:
Improvecharging efficiencyVSAvoidenergy storage capacity
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent implements dynamic charging mode switching between constant current and constant power modes based on real-time voltage and current conditions. The system transitions from constant current mode at lower voltages to constant power mode at higher voltages, optimizing both charging efficiency and energy storage capacity utilization throughout the charging process.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the charging parameters dynamically by switching between different charging modes (constant current, constant power, and their combinations) based on the supercapacitor's voltage state. This parameter change strategy ensures efficient charging at low voltages while preventing excessive voltage differences at high voltages, thereby protecting energy storage capacity.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If constant voltage charging is used, then voltage stability is improved, but charging efficiency deteriorates and charging time increases

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

Solution Approach 1:

The system dynamically switches between constant voltage mode and constant power mode based on real-time conditions. During early charging stages or when faster charging is needed, the system operates in constant power mode to increase charging speed. When voltage stability becomes critical, it transitions to constant voltage mode, thereby achieving both fast charging and voltage stability throughout the charging process.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs periodic mode switching between constant voltage and constant power charging based on voltage thresholds and charging progress. This periodic action allows the system to alternate between speed optimization and stability maintenance, achieving overall improved charging efficiency while maintaining necessary voltage stability.

Inventive Principle:
Principle #19Periodic action

3Productivity

If constant power charging is used, then charging speed is improved, but control circuit complexity increases

Engineering Contradiction:
Improvecharging speedVSAvoidcontrol circuit complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent merges constant current charging and constant power charging into a unified control system that automatically switches between modes. By combining these modes and using a single controller that handles both constant current and constant power operations based on voltage thresholds, the system achieves fast charging without requiring separate complex control circuits for each mode.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The control circuit is designed with multi-functionality to handle both constant current and constant power charging modes within a single unified controller. This universal controller adjusts its operation based on real-time voltage and current conditions, eliminating the need for separate dedicated control circuits for each charging mode and thereby reducing overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Stability of the object's composition

If conventional DAC control chip is used for constant voltage charging, then voltage control is achieved, but additional circuit costs are required

Engineering Contradiction:
Improvevoltage controlVSAvoidcircuit cost
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The voltage boost/buck controller is designed with multi-functionality to perform both voltage regulation and constant power control functions. This universal controller eliminates the need for separate DAC control chips by integrating multiple control capabilities into a single device, thereby achieving precise voltage control without additional circuit costs.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the functions of the DAC control chip and the voltage boost/buck controller into a single integrated control system. By combining these previously separate components into one unified controller that can perform both digital-to-analog conversion and voltage regulation, the system achieves the same voltage control performance while reducing circuit complexity and cost.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4369565A1Charging circuitry, charging method and power system for supercapacitor
Publication Date: 2024.05.15 DELTA ELECTRONICS INC(CN)
  • EP4369565A1 patent drawingFigure 1
  • EP4369565A1 patent drawingFigure 2
  • EP4369565A1 patent drawingFigure 3

AI summary

A charging circuitry (10A) includes a power electronic converter (13), a current sensor (14), a voltage boost/buck controller (15) and a charging mode controller (16). The power electronic converter (13) is configured to charge or discharge a supercapacitor (12) according to a control command (CTRL). The current sensor (14) is coupled to the supercapacitor (12) for detecting a first sensed voltage (ISENSE+) and a second sensed voltage (ISENSE-). The voltage boost/buck controller (15) is configured to generate the control command (CTRL) and a current command (IMON_OUT) according to the first (ISENSE+) and second sensed voltages (ISENSE-) and an overall feedback (FB_OUT). The charging mode controller (16) is configured to generate a current feedback (FB1) and a voltage feedback (FB2) to the voltage boost/buck controller (15) according to a driving voltage (CV), the current command (IMON_OUT) and a third sensed voltage (VSENSE) of the supercapacitor (12). The third sensed voltage (VSENSE), the current feedback (FB1) and the voltage feedback (FB2) are superposed as the overall feedback (FB_OUT) and then inputted to the same input terminal of the voltage boost/buck controller (15).