Electric Power ›› 2025, Vol. 58 ›› Issue (9): 183-193.DOI: 10.11930/j.issn.1004-9649.202502005

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A Forecast Method for Electricity Spot Market Clearing Prices Based on Fractal Theory

WU Wenzu1(), WANG Xuhui2(), LU Yuan3(), CHEN Wan1, TIAN Shijin4, CHEN Xian5   

  1. 1. Power Dispatching and Control Center, China Southern Power Grid, Guangzhou 510000, China
    2. Yunnan Power Dispatching and Control Center, China Southern Power Grid, Kunming 650000, China
    3. Guangdong Power Exchange Center Co., Ltd., Guangzhou 510699, China
    4. Electric Power Dispatching Control Center of Guizhou Power Grid Co., Ltd., Guiyang 550000, China
    5. Guangzhou Power Supply Bureau, Guangdong Power Grid Co., Ltd., Guangzhou 510620, China
  • Received:2025-02-07 Online:2025-09-26 Published:2025-09-28
  • Supported by:
    This work is supported by National Key Research and Development Program of China (No.2024YFB2409000), Science and Technology Project of Southern Power Grid Power Dispatching and Control Center (No.0005KK52220042).

Abstract:

To address the complex fluctuations of electricity spot market clearing prices with high proportion integration of new energy, this paper proposes a clearing price prediction method based on fractal theory. Firstly, the clearing price fluctuations are analyzed from monofractal and multifractal dimensions, and corresponding prediction models are constructed. Secondly, based on the monofractal prediction method, the long-term memory and self-similarity of clearing prices are quantified using the Hurst indices and box dimension; based on multifractal method, the local fluctuation anomalies caused by sudden changes in new energy output are effectively captured via pattern matching. Thirdly, the proposed method is verified with clearing price data from five regions, which shows that, compared to the traditional "ARIMA + neural network" approach, the proposed method significantly improves the prediction accuracy, with the maximum error decreasing from 43.95% to 8.41%. In-depth applicability scenario analysis indicates that, when the Hurst index is large, the monofractal-based prediction method is more applicable; when multifractal features dominate, the multifractal-based prediction method is preferable.

Key words: new energy, spot market, clearing electricity price, fractal theory, monofractal, multifractal