Photovoltaic Power Interval Prediction via NSGA-II-DLSSVM

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Solution Overview

Problem

Existing methods for predicting photovoltaic power output are inaccurate and unreliable, especially in bad weather conditions, as they ignore uncertainty and often assume normal distribution, leading to local extreme values and reduced reliability.

Innovation Solution

A short-term interval prediction method using an NSGA-II-based double least squares support vector machine (NSGA-II-DLSSVM) that considers numerical and pattern similarity through fuzzy C-means clustering and Fre'chet distance, optimizing model parameters to provide a more reliable interval prediction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If data point prediction methods are used for photovoltaic power output, then the prediction process is simple, but the prediction accuracy is reduced sharply in bad weather conditions and reliability cannot be described

Engineering Contradiction:
Improveprediction model complexityVSAvoidprediction reliability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The prediction method is segmented into two distinct models: a point prediction model for deterministic output and an interval prediction model for uncertainty quantification. This segmentation allows each model to specialize in its strength while collectively providing both simplicity and reliability in photovoltaic power output prediction

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent creates a composite prediction framework by combining multiple prediction approaches (point prediction and interval prediction) into a unified system. This composite structure integrates the simplicity of point prediction with the reliability of interval prediction, achieving both goals simultaneously

Inventive Principle:
Principle #40Composite materials

2Reliability

If traditional neural network models are used for interval prediction, then the model can be constructed, but it is easy to fall into local extreme values and difficult to avoid defects

Engineering Contradiction:
Improveinterval prediction reliabilityVSAvoidprediction precision
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent replaces the traditional neural network optimization mechanism with a multi-objective optimization algorithm. This substitution eliminates the mechanical defect of local extreme values by using a different optimization approach that simultaneously considers multiple objectives (coverage probability and interval width), achieving both reliability and precision

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

3Device complexity

If assumption of normal distribution is made for photovoltaic power output, then the prediction model is simple to construct, but distribution errors are ignored and prediction accuracy is reduced

Engineering Contradiction:
Improvemodel construction complexityVSAvoidprediction accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent changes the fundamental parameter assumption from normal distribution to a data-driven distribution obtained through clustering analysis. This parameter change allows the model to adapt to actual photovoltaic power output patterns without requiring complex theoretical distributions, maintaining simplicity while improving accuracy by reflecting real-world distribution characteristics

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS11070056B1Short-term interval prediction method for photovoltaic power output
Publication Date: 2021.07.20 DALIAN UNIV OF TECH
  • US11070056B1 patent drawing
  • US11070056B1 patent drawing
  • US11070056B1 patent drawing

AI summary

The present disclosure belongs to the technical field of information, provides a short-term interval prediction method for photovoltaic power output, and is a short-term interval prediction method for photovoltaic power output based on a combination of a multi-objective optimization algorithm and a least square support vector machine. The present disclosure firstly proposes a similar day classification method considering both numerical value and pattern similarity to enhance the regularity of samples, then constructs an adaptive proportional interval estimation model based on dual-LSSVM model, and optimizes model parameters by using NSGA-II algorithms to realize the interval prediction of photovoltaic power output. Results obtained by the method have high accuracy, and computation efficiency meets actual application requirements. The method can also be popularized and applied in the fields of grid connection and scheduling of renewable energy sources.