Capacitor Bank Switching Optimization for Distribution Networks

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Solution Overview

Problem

Conventional methods for optimizing capacitor bank switching in electricity distribution systems are inadequate for large-scale, meshed, multi-source, multi-phase unbalanced networks due to simplified models, low computation efficiency, and limited optimizing capability, making them unsuitable for real-world distribution systems.

Innovation Solution

A computer program product that determines optimal capacitor bank switching by building a network model, calculating current sensitivity vectors, and constructing a mixed integer quadratically constrained quadratic optimization problem (MIQCQP) to find optimal control settings for minimizing energy loss, using a computer-readable medium with embedded program instructions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional simplified models are used for capacitor bank switching optimization, then the model is easier to implement, but it cannot accurately represent real large-scale meshed multi-phase unbalanced distribution systems

Engineering Contradiction:
Improveease of implementationVSAvoidmodel accuracy
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent transforms the capacitor bank switching optimization problem into a mixed-integer quadratic programming (MIQP) formulation, changing the mathematical parameters and solution approach to handle large-scale meshed multi-phase unbalanced systems while maintaining computational efficiency

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces conventional simplified optimization methods with an advanced MIQP-based computational approach, substituting the old mechanical optimization process with a more sophisticated mathematical programming system that can handle complex network conditions

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

2Productivity

If conventional optimization methods are applied to large-scale distribution systems, then comprehensive system coverage is achieved, but computation efficiency becomes too low for online or offline applications

Engineering Contradiction:
Improvesystem coverageVSAvoidcomputation efficiency
Core Design Contradiction:
ProductivityVSSpeed

Solution Approach 1:

The patent reformulates the optimization problem as a mixed-integer quadratic programming model with specific parameter transformations that enable efficient computation using standard solvers, achieving both comprehensive system coverage and acceptable computation speed

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a systematic mathematical modeling approach that creates an accurate computational representation (copy) of the physical distribution system, allowing the optimization to be performed on the model rather than requiring direct complex calculations on the actual large-scale system

Inventive Principle:
Principle #26Copying

3Device complexity

If conventional optimization methods are used, then the implementation is simpler, but the optimizing capability is limited and cannot handle complex unbalanced distribution networks

Engineering Contradiction:
Improveimplementation complexityVSAvoidoptimizing capability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent develops a universal MIQP-based optimization framework that can handle various types of distribution systems (radial, meshed, multi-phase, unbalanced) through a single unified approach, enhancing adaptability while maintaining reasonable implementation complexity

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

Solution Approach 2:

The patent changes the mathematical formulation parameters to quadratic programming form, which provides better optimizing capability for complex networks while using standard solvers that keep implementation complexity manageable

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2362978B1Reactive power optimization
Publication Date: 2013.01.02 ABB RES LTD
  • EP2362978B1 patent drawingFigure 1
  • EP2362978B1 patent drawingFigure 2
  • EP2362978B1 patent drawingFigure 3

AI summary

Var optimization (VARO) is a subsystem of a voltage and var optimization (VVO) system that processes a capacitor switching optimization problem. The VARO is a self contained process that may work stand alone or in conjunction with a Voltage Regulation Optimization (VRO) system to provide integrated VVO solutions. The VARO system takes network inputs and calculates optimal settings for distribution network capacitor banks.