Grid Frequency Control via Energy Storage Switching

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Solution Overview

Problem

Spinning reserve generators in electricity generation and distribution systems require significant time to reach output levels, increasing costs and emissions, and existing systems struggle to quickly respond to power disruptions or load changes.

Innovation Solution

A control system that autonomously connects a supplemental power system to the main electrical grid in response to frequency deviations, utilizing fast-start generators and energy storage systems to provide immediate power support, thereby reducing the need for spinning reserves and minimizing fuel consumption and emissions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If spinning reserve generators are used to meet demand during power disruptions, then grid reliability is improved, but response time increases significantly (ten minutes or more) and operational costs increase

Engineering Contradiction:

Improvegrid reliabilityVSAvoidresponse time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary action by pre-charging energy storage systems (batteries, capacitors, flywheels) during normal grid operation. When a power disruption or frequency deviation occurs, these pre-charged systems immediately discharge to provide power support, eliminating the ten-minute startup delay of traditional spinning reserve generators while maintaining grid reliability

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The invention replaces the mechanical spinning reserve generator system with an energy storage system controlled by a controller that monitors grid frequency. The energy storage system can respond electronically and instantaneously to frequency deviations, substituting the slow mechanical response of traditional generators with fast electronic control and energy discharge mechanisms

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If spinning reserve generators are maintained in standby to provide backup capacity, then power supply security is improved, but operational costs and emissions increase

Engineering Contradiction:

Improvepower supply securityVSAvoidfuel consumption

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The system replaces fuel-consuming spinning reserve generators with energy storage systems (batteries, capacitors, flywheels) that store electrical energy during normal operation and discharge during disruptions. This substitution eliminates continuous fuel consumption and emissions associated with maintaining mechanical generators in standby, while providing equivalent or superior response capability

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the operational parameters from continuous mechanical standby operation to periodic energy storage and discharge cycles. The energy storage systems are charged during normal grid operation and discharged only when needed, transforming the continuous energy consumption model into an on-demand model that reduces overall fuel consumption and emissions while maintaining power supply security

Inventive Principle:

Principle #35Parameter changes

3Productivity

If traditional power generation systems are used to respond to load increases, then power demand is met, but response speed is insufficient and system flexibility is reduced

Engineering Contradiction:

Improvepower outputVSAvoidresponse speed

Core Design Contradiction:

ProductivityVSSpeed

Solution Approach 1:

The system replaces traditional mechanical power generation systems with energy storage systems controlled by electronic controllers that can respond instantaneously to load changes. The controller monitors grid frequency and automatically discharges energy storage systems when frequency drops, providing rapid power output increases without the mechanical inertia and startup delays of traditional generators

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention introduces dynamic response capability through energy storage systems that can rapidly adjust their discharge rate based on real-time grid conditions. The controller continuously monitors frequency and modulates the energy discharge to match the instantaneous power demand, providing dynamic and flexible response to load changes that mechanical systems cannot achieve

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS10935945B2Methods and apparatus for power generation and distribution

Publication Date: 2021.03.02 ARIZONA PUBLIC SERVICE CO

AI summary

Methods and apparatus for power generation and distribution according to various aspects of the present invention may operate in conjunction with a control system for controlling electrical power flowing between a main electrical grid providing main electrical grid power having a frequency, a supplemental power system, and a load. The control system may operate in conjunction with a switch system, wherein the switch system selectively connects the supplemental power system to the main electrical grid. A controller may be responsive to the main electrical grid power frequency and control the switch system. The controller may compare the main electrical grid power frequency to a first threshold and autonomously cause the switch system to connect the supplemental power system to the main electrical grid in response to the frequency of the main electrical grid power crossing the first threshold.