Tie-Line Reserve Power Probability Margin for Day-Ahead Dispatching in Power Systems with High Proportion Renewable Power Sources

Yue Chen,Zhizhong Guo,Guizhong Wang,Yingwei Hou,Abebe Tilahun Tadie,Hongbo Li

doi:10.3390/en12244742

Yue Chen, Zhizhong Guo + Show 4 more

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https://doi.org/10.3390/en12244742

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Abstract

In power systems with a high proportion of renewable power sources (PSHPRPSs), the power constraints of the tie-line may limit the ability of the reserve power to accommodate uncertain power generation, resulting in difficulties for the grid power balance. As uncertain power generation cannot be predicted accurately and in accordance with the law of probability and statistics, it is necessary to use a probability model to calculate the uncertain power of the tie-line. Here, day-ahead prediction error probability optimal power flow (DPEPOPF) is proposed to calculate the tie-line reserve power probability margin (TRPPM) in day-ahead dispatching. In day-ahead dispatching, TRPPM is reserved for real-time dispatching to accommodate uncertain power generation, so as to avoid tie-line power congestion. This study classifies the area of the grid based on the principle of area control error accommodation, and the DPEPOPF is divided into two categories: An inter-area day-ahead prediction error probability optimal power flow mathematical model, and an intra-area day-ahead prediction error probability optimal power flow mathematical model. The point estimate optimization algorithm was implemented in MATLAB 8.3.0.532 (R2014a) to calculate the TRPPM. The simulation results verify the accuracy of the model and effectively avoid power congestion of the tie-line.

Highlights

Renewable power sources such as wind and solar power have uncertainties characterized based on randomness and intermittence
The power prediction error is within the regulation range of the automatic generation control (AGC); there is no requirement for other power balance links
We developed a mathematical model of day-ahead prediction error probability optimal power flow (DPEPOPF), which solves the numerical characteristics of the tie-line reserve power probability margin (TRPPM) in day-ahead dispatching

Summary

Introduction

Renewable power sources such as wind and solar power have uncertainties characterized based on randomness and intermittence. In order to maintain grid power balance, the PSHPRPSs must have a dispatch control system (DCS) with power accommodation capability to accommodate uncertain power generation. Conventional power grids do not have any uncertain power sources, so the day-ahead prediction of load power is relatively accurate. The power prediction error is within the regulation range of the automatic generation control (AGC); there is no requirement for other power balance links. Because of the large proportion of uncertain power sources, the error in day-ahead power prediction for PSHPRPSs is large, and the AGC cannot balance the uncertain power unless a real-time scaled power balance link is added. For the grid DCS, Energies 2019, 12, 4742; doi:10.3390/en12244742 www.mdpi.com/journal/energies

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