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Wednesday, 12 March 2014
16:30 - 18:00 Storage & grid integration
Hardware Technology  


Room: Tramuntana
Session description

As wind energy becomes an increasingly important power supply technology in many countries, the wind energy sector has to keep on working in collaboration with system operators and develop the technological solutions that are required. This session will present new developments that will consolidate wind energy as a major element of electricity systems: wind turbine group (WTG) hardware and software, new control strategies from WTG to global power systems as well as storage solutions.

Learning objectives

  • Identify new WTG capabilities for grid operation support
  • Analyse new control strategies at both WTG and wind farm level
  • Understand how wind energy will/can be managed in future scenarios and at high penetrations
  • Examine what is at stake to consolidate wind energy as the future leading energy source
  • Identify and analyse electricity storage business models
Lead Session Chair:
Luis Polo, AEE, Spain

Co-chair(s):
Santiago Arnaltes, University Carlos III of Madrid - UC3M, Spain
Gerardo Gonzalez REE, Spain
Co-authors:
Gerardo Gonzalez (1) F P
(1) REE, Madrid, Spain

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Presenter's biography

Biographies are supplied directly by presenters at EWEA 2014 and are published here unedited

Mr. Gerardo González has been worrking in the electrical industry for 22 years. He studied industrial engineering at the Madrid Politechnical University. He is currently a technical assistant in the Electrical System Reliability Department at Red Eléctrica de España (REE), the Spanish Transmission System Operator. He has been involved in various areas in REE (regulation, operation planning, long term planning, network studies) dealing with renewable integration in the grid. Has participated in EU projects as EWIS, Anemos and Twenties.

Abstract

Dynamic line rating (RTTR) versus seasonal rating in the electrical transmission network. correlation between wind power production and RTTR

Introduction

Wind energy integration in the network requires more accurate calculation of the transmission capacity of overhead lines than actually used seasonal rating. The conductor temperature is usually the factor that determines the transmission capacity of a line, in order to avoid excessive sags and possible damages in the materials. Hence, a proper control of the conductor temperature along the line and during time will help to maximize this capacity.

Approach

In order to be able to assess the value of the temperature, a special kind of conductor called OPPC (Optical Phase Conductor) where fiber optics are integrated has been installed by REE in 220 kV Fuendetodos-María line as part of Twenties EU Project. Through a DTS (Distributed temperature sensor) system located in Maria substation, a laser pulse is sent through the fiber optics and by processing this signal it is possible to monitor the temperature each 2 meters with ± 2ºC. Along the line 6 weather stations have been installed.

Main body of abstract

All this information (15,020 points of conductor temperature data, current values, time signal, other calculations) is sent to the Central System (CSTW) for transmission capacity calculations.The objective of this paper is to analyze the existence of correlation between the real ampacity of the line and wind power production in areas close to the line. The analysis of the correlation level between wind energy produced by the wind farms and the ampacity of the line (Real-Time Thermal Rating -RTTR-) is a key point in order to obtain the degree of dependence between generation and transmission facilities availability. From a statistical point of view the correlation refers to any of a broad class of statistical relationships that involves dependence.This analysis will be done based on the correlation between the parameters considering not only electrical and meteorological variables but also spatial distribution of facilities. Additional analysis of the sensitivity of the RTTR to wind speed, irradiation and ambient temperature will be carried out considering the distance from the wind farms to the power line. It has been assessed the correlation factor of RTTR [MVA] vs P [MW] considering the mean distance between the wind farm and the power line and their linear correlation formula.

Conclusion

Correlation between wind farms production and RTTR is clearly related to the average distance between the wind farms and the line and is an important factor in terms of the level of correlation between variables. Moving away from the line, increases the likelihood of lowering the level of correlation. In other hand, as much as closer the wind farm is to the line, higher relationship exists between the level of power generated by the wind farms and the ampacity of the line.


Learning objectives
It is possible to operate the line over the seasonal ratings in a safety way to facilitate the integration of wind energy in the power system. Weather stations, RTTR and DTS are key technology assets to achieve this goal.