Demand Response Load Selection Using Electrical Distance Metrics

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Solution Overview

Problem

Current demand response selection methods in power distribution networks are inefficient due to their random nature and inability to optimize load reduction in complex topologies, leading to suboptimal selection of demand responsive loads and increased power loss.

Innovation Solution

A mathematical network model is used to evaluate power loss in power distribution networks, allowing for the selection of demand responsive loads that maximize reduction in power loss while meeting load reduction targets and network constraints, accommodating mesh networks and distributed generation systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If random selection method is used for demand responsive loads, then selection process is simple, but power loss reduction is suboptimal

Engineering Contradiction:
Improveselection process simplicityVSAvoidpower loss
Core Design Contradiction:
Ease of manufactureVSLoss of energy

Solution Approach 1:

The invention changes the selection criterion from random selection to selection based on electrical distance metric. The electrical distance is calculated using power flow equations and impedance values, transforming the selection parameter from arbitrary to physically meaningful, thereby optimizing power loss reduction while maintaining computational feasibility.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention replaces the random mechanical selection process with a mathematical optimization approach using power flow equations and electrical distance calculations. This substitution enables systematic optimization of load selection to minimize power loss while satisfying demand response targets.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Loss of energy

If electrical distance model is used for load selection, then power loss evaluation is improved, but application to mesh networks and complex topologies is complicated

Engineering Contradiction:
Improvepower loss evaluation accuracyVSAvoidnetwork topology complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The invention creates a universal load selection methodology based on electrical distance that works across different network topologies including radial and mesh networks. The power flow equations and electrical distance calculations are formulated to be topology-agnostic, enabling the same approach to be applied universally without requiring topology-specific modifications.

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

Solution Approach 2:

The invention segments the complex network analysis into manageable components: (1) power flow equation formulation for each branch, (2) electrical distance calculation for each load, (3) sorting and selection based on electrical distance metrics. This segmentation makes the approach computationally tractable for complex mesh networks while maintaining accuracy.

Inventive Principle:
Principle #1Segmentation

3Loss of energy

If model-based load selection is used, then power loss reduction is optimized, but computational complexity increases

Engineering Contradiction:
Improvepower loss reductionVSAvoidcomputational complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The invention applies partial action by calculating electrical distance metrics only for candidate loads that meet basic demand response criteria, rather than performing full power flow analysis for all loads in the network. This selective approach optimizes power loss reduction while limiting computational complexity to only the necessary subset of loads.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The invention performs preliminary filtering of candidate loads based on demand response eligibility criteria before applying the computationally intensive electrical distance calculations. This preliminary action reduces the number of loads requiring detailed analysis, thereby optimizing power loss reduction while managing computational resources efficiently.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS9577435B2Method and apparatus for managing demand response resources in a power distribution network
Publication Date: 2017.02.21 HITACHI ENERGY LTD
  • US9577435B2 patent drawing
  • US9577435B2 patent drawing
  • US9577435B2 patent drawing

AI summary

In one aspect of the teachings herein, demand responsive loads are selected for involvement in a given DR event using an advantageous approach to selection that is based on using a mathematical network model to evaluate power loss in a power distribution network as a function of different combinations of demand responsive load selections and corresponding load reduction values. The mathematical network model comprises a mathematical representation of the power distribution network as a multi-phase unbalanced distribution network, including mathematical representations of the physical components in the power distribution network and the connecting relationships of those components. As overall power loss in the system is a function of different combinations of demand responsive load selections, the mathematical network model is used to evaluate system power loss under different demand response load selections, in a manner that automatically accommodates mesh networks and other complex network topologies, distributed generation sources, etc.