Electric Energy Storage Apparatus AC Output Without Converters

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Solution Overview

Problem

Conventional electric energy storage apparatuses using DC-DC converters and inverters face inefficiencies, increased noise, and larger size due to the need for wide input voltage ranges and high voltage switching, especially when using capacitors with varying output characteristics.

Innovation Solution

An electric energy storage apparatus that generates AC output without a DC-DC converter or inverter, utilizing a balancing circuit and switch groups to adjust output voltage and polarity, allowing for low-loss and low-noise operation across a wide output intensity range.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a DC-DC converter is used to convert varying capacitor output voltage to a fixed operating voltage, then the output voltage stability is improved, but the energy loss increases and the apparatus size increases

Engineering Contradiction:

Improveoutput voltage stabilityVSAvoidenergy loss

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent removes the DC-DC converter from the system entirely. Instead of using a converter to stabilize voltage, the invention directly connects the capacitor to the load, accepting the natural voltage variation without active conversion, thereby eliminating the energy loss and size penalty of the converter

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

Rather than actively converting varying voltage to fixed voltage through a DC-DC converter, the invention inverts the approach by directly utilizing the varying capacitor voltage to drive the AC output, turning what was previously seen as a problem (voltage variation) into an acceptable characteristic of the system

Inventive Principle:

Principle #13The other way round (Inversion)

2Reliability

If a DC-DC converter with transformer and coil is used, then the voltage conversion function is achieved, but the apparatus size and weight increase

Engineering Contradiction:

Improvevoltage conversion capabilityVSAvoidapparatus weight

Core Design Contradiction:

ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent extracts and removes the transformer and coil components from the system. By eliminating these magnetic components, the invention achieves voltage output without the weight penalty, while still maintaining the ability to generate AC power through direct capacitor discharge

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention replaces the mechanical/electromagnetic voltage conversion system (transformer and coil) with a direct electrical connection approach. The capacitor directly supplies voltage to the inverter circuit without intermediate magnetic conversion components, substituting a simpler electrical system for the complex electromagnetic one

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Power

If high voltage switching is performed in the inverter, then the AC output voltage is achieved, but the noise level increases

Engineering Contradiction:

ImproveAC output voltageVSAvoidnoise

Core Design Contradiction:

PowerVSObject-generated harmful factors

Solution Approach 1:

The patent applies preliminary action by pre-charging the capacitor to a high voltage level before AC output is needed. This allows the inverter to operate at lower voltage switching levels during AC generation, reducing noise while still achieving the required output power through the energy already stored in the capacitor

Inventive Principle:

Principle #10Preliminary action

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

Enables efficient, low-noise AC output with reduced apparatus size by eliminating the need for DC-DC converters and inverters, and allows for regenerative energy return and precise load voltage control.

Implementation Method 1

an electric energy storage apparatus capable of generating an AC output in a low-loss and low-noise manner without using a DC (direct current) -DC converter and an inverter

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentEP2475084B1Electricity-storage device that can output alternating current

Publication Date: 2020.03.25 JAPAN CAPACITOR IND CO LTD

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AI summary

Provided is an electric energy storage apparatus capable of generating an AC output in a low-loss and low-noise manner without using a DC-DC converter or an inverter. The electric energy storage apparatus comprises: an electric energy storage module group formed by connecting in series two or more electric energy storage modules each comprising one or more electric energy storage elements; a balancing circuit electrically connected to the electric energy storage module group and configured to adjust a voltage to be applied to each of the electric energy storage modules; a first switch group comprising two or more switches each provided in a path connecting a first terminal and a terminal of one of the series-connected electric energy storage modules; and a second switch group comprising two or more switches each provided in a path connecting a second terminal and a terminals of one of the series-connected electric energy storage modules. The electric energy storage apparatus is configured to perform a switch changeover in the first and second switch groups so as to select a magnitude and polarity of an output voltage depending on a configuration of the electric energy storage elements present in a path connecting the first and second terminals.