Stirling DC Power Plant with Capacitor-Bank Engine Starting

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Solution Overview

Problem

Traditional power generation and distribution systems face inefficiencies due to the need for conversion from AC to DC power, particularly in local generation and distribution, and lack an efficient means to start and control Stirling engines for DC power production.

Innovation Solution

A modular power system that includes a backplane, microprocessors, half-bridge circuits, power conditioning elements, and sensors to control rotating power generators, such as Stirling engines, for producing DC power, with features like a small power supply supplemented by a capacitor bank for starting, and a method to disable output during pre-selected conditions to manage current flow and emissions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If a traditional AC power generation system is used, then power can be transmitted over long distances, but conversion losses occur when converting AC to DC for local appliances

Engineering Contradiction:
Improveconversion lossVSAvoidpower conversion infrastructure
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent extracts the AC-to-DC conversion step from the traditional power distribution chain by implementing direct AC generation. The Stirling engine directly drives an AC generator to produce AC power that can be used locally without conversion, eliminating the energy loss and infrastructure complexity associated with AC-DC conversion for local appliances.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a capacitor bank as an intermediary energy storage device to enable direct AC generation. The capacitor bank provides the necessary reactive power and voltage support to allow the Stirling engine-AC generator system to operate efficiently and directly power AC appliances without traditional conversion infrastructure.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If a Stirling engine is used for DC power generation, then local power production is achieved, but the engine requires an efficient starting mechanism

Engineering Contradiction:
Improvelocal power generationVSAvoidengine starting
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The patent applies preliminary action by using a capacitor bank to pre-store the energy needed for engine starting. Before the Stirling engine begins operation, the capacitor bank is charged and then discharged to provide the high starting torque needed to get the engine running, eliminating the need for complex external starting mechanisms.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system achieves self-service through the capacitor bank, which automatically charges during engine operation and discharges during starting. This creates a self-contained starting system that doesn't require external batteries or complex motor-driven starters, simplifying the overall system operation.

Inventive Principle:
Principle #25Self-service

3Device complexity

If dispersed local power generation is implemented, then operational overhead is reduced, but control and measurement of power output becomes more difficult

Engineering Contradiction:
Improveoperational overheadVSAvoidpower output control
Core Design Contradiction:
Device complexityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent implements feedback control by monitoring the actual power output of the Stirling engine-AC generator system and using this information to adjust engine operation. Sensors measure voltage, current, and power output, and this data feeds back to the control system to optimize performance and simplify operational management of the dispersed generation unit.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control system is designed with multi-functionality to handle various tasks including power output measurement, engine control, capacitor bank management, and grid interaction. This universal control approach simplifies operational overhead by consolidating multiple functions into a single integrated system rather than requiring separate specialized devices for each function.

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

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 efficiently produces DC power, reduces emissions, and effectively controls Stirling engine velocity, enhancing the reliability and efficiency of local power generation and distribution.

Implementation Method 1

starting an engine using power supplied by a relatively small power supply supplemented by a capacitor bank

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 2

providing output from the engine to a generator, producing alternating current (AC) power

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS11859589B2Direct current power plant
Publication Date: 2024.01.02 DEKA PRODUCTS LP
  • US11859589B2 patent drawing
  • US11859589B2 patent drawing
  • US11859589B2 patent drawing

AI summary

A DC power plant generating DC power from a variety of engines including a Stirling cycle engine. The DC power plant includes a relatively small start-up power source that is discontinued after the engine is running. A method for producing DC power for a load including starting up an engine using power supplied by a relatively small power supply supplemented by a capacitor bank, providing output from the engine to a generator, producing alternating current (AC) power by the generator, converting the AC power to direct current (DC) power, disabling output of the DC power during a first set of pre-selected conditions, limiting a rate of change of current of the DC power during a second set of pre-selected conditions, reducing conducted and radiated emissions of the DC power, disconnecting the DC power from the load under a third set of pre-selected conditions, and providing the DC power to the load.