Next Article in Journal
Performance Analysis of a Grid-connected High Concentrating Photovoltaic System under Practical Operation Conditions
Next Article in Special Issue
Investigation of a High Head Francis Turbine at Runaway Operating Conditions
Previous Article in Journal
Synthesis and Characterization of Sulfonated Poly(Phenylene) Containing a Non-Planar Structure and Dibenzoyl Groups
Previous Article in Special Issue
Simulation of Wind Speed in the Ventilation Tunnel for Surge Tanks in Transient Processes
Article Menu
Issue 2 (February) cover image

Export Article

Open AccessArticle
Energies 2016, 9(2), 114;

A New Fluctuation Index: Characteristics and Application to Hydro-Wind Systems

1,2,* , 1,2
State Key Laboratory of Water Resource and Hydropower Engineering Science, Wuhan University, Wuhan 430072, Hubei, China
Hubei Collaborative Innovation Center for Water Resources Security, Wuhan 430072, Hubei, China
POWERCHINA Kunming Engineering Corporation Limited, Kunming 650051, Yunnan, China
Author to whom correspondence should be addressed.
Academic Editor: Ånund Killingtveit
Received: 25 November 2015 / Revised: 2 January 2016 / Accepted: 25 January 2016 / Published: 18 February 2016
(This article belongs to the Special Issue Hydropower)
Full-Text   |   PDF [7197 KB, uploaded 18 February 2016]   |  


Hydro-wind system output fluctuations are the primary factors used to assess the effects of hydropower on power companies compensating for wind power intermittency. Considering that most fluctuation indices can only characterize one aspect of fluctuations, namely, the quantitative or contour variations, we present a new index that uses the standard deviation (SD) and rotation angle to detect the quantitative variations and contour changes, respectively. Herein, the new index is compared with commonly used indices, specifically, the first-order difference, SD, and Richards-Baker flashiness indices. The results of tests performed using various processes and disposals show that: (1) when dealing with the process by moving average, repeating or overlay disposal, the new index performs comparably to the other indices, while when dealing with the process by zooming disposal, it more fully describes the fluctuation characteristics by taking both quantitative and contour variations into consideration; (2) when the new index is used to characterize the hydro-wind output fluctuations with different resources and capacities, the outcomes coincide with the mechanisms of hydro-wind systems. This study presents a new way to characterize the fluctuation of hydro-wind output. View Full-Text
Keywords: fluctuation characterization; hydro-wind output; standard deviation; rotation angle fluctuation characterization; hydro-wind output; standard deviation; rotation angle

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Share & Cite This Article

MDPI and ACS Style

Wang, X.; Mei, Y.; Cai, H.; Cong, X. A New Fluctuation Index: Characteristics and Application to Hydro-Wind Systems. Energies 2016, 9, 114.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Energies EISSN 1996-1073 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top