水利水电工程毕业设计外文翻译.doc

1、外文翻译The changing role of hydropower: from cheap local energy supply to strategic regional resourceAbstract: The role of hydropower has evolved from being a local, low-cost energy source to being a flexible resource offering a variety of ancillary services including regional frequency control and ene

2、rgy storage for large interconnected power systems. This paper explores this development as it relates to a North American midcontinent electrical power region. It reviews traditional benefits from hydropower in a thermal-power-dominated region and traditional efforts to quantity those benefits. Wit

3、h the challenges of integrating increasing quantities of variable generation such as wind and solar power, new benefits from hydropower have been identified and new methods to quantify those benefits have been developed. Recent results of a major study of the sub-hourly behaviour of a hydropower sys

4、tem in a Midwestern United States electrical market are reviewed.Keywords: conventional hydropower, renewable integration, accommodating variable generation, hydro plant optimization, benefits of hydropower In the past, there have been many drivers for integrating Canadian hydropower systems with th

5、ermal systems in the United States. They included the sale of surplus hydraulic energy, leveraging the load diversity between warmer and cooler climates, short-term energy arbitrage, system reliability improvements, and fuel diversification and emission reduction.More recently, increased penetration

6、 levels of variable renewable generation, such as wind and solar power, are increasing the uncertainty and variability in the electric loadsupply balance. This poses challenges to the operation of regional electrical systems. The flexibility and energy-storage characteristics of hydropower can assis

7、t electrical utilities and system operators in managing the variability through load balancing and shifting energy production to more opportune times. Many hydro facilities already provide similar balancing services for load, while others may not be able to because of operational restrictions.Tradit

8、ional benefit analyses may not adequately capture all the economic benefits attributable to flexible hydro generation, thus leaving something on the table when justifying new developments. With the growth in variable renewable resources, there is an increased need for more comprehensive benefit calc

9、ulations. Several major studies in the US have attempted to fully quantify the benefits hydropower brings to the electrical system using hourly market simulations (GE Energy, 20109. GE Energy. (2010). Western Wind and Solar Integration Study. A key conclusion of these studies is that to fully captur

10、e the benefits arising from the synergy of hydropower and variable renewable generation, sub-hourly modelling and analysis are required.The Manitoba Hydro Wind Synergy Study (MHWSS), completed by the Midcontinent Independent System Operator (MISO) and Manitoba Hydro (MH), is one of the first power-m

11、arket modelling studies aimed at quantifying the benefits of hydropower at sub-hourly timeframes. The study explicitly models the variability in wind power and the energy-storage capabilities of major hydropower facilities in Manitoba, in addition to the typical characteristics of day-ahead and real

12、-time energy and ancillary-services markets. The benefits are quantified in terms of system operating-cost reductions. Other benefits, including reductions in wind curtailments, and a description of the synergy between wind and hydro are presented.This article is broken into several sections. The fi

13、rst section presents the history of electric power growth in Manitoba and the traditional benefits associated with hydrothermal integration. The second section describes the role of hydropower in the integration of variable generation technologies and the previous efforts to quantify the benefits fr

14、om hydropower. The final section presents a recent study in the US Midwest and conclusions from that work.Hydropower resources are not distributed uniformly around the globe. Some regions are hydro-rich; others have few existing or potential hydro-generation sites. Regions rich in hydropower resourc

15、es have traditionally developed hydro-dominated generation fleets and benefited from low-cost energy, while in regions with fewer hydropower resources, hydropower, where available, has played a relatively minor role.Three common electrical power sources in North America are steam-thermal (e.g. coal

16、and nuclear), combustion turbine (gas) and hydropower. Steam-thermal stations are relatively difficult to start and stop and to ramp up or down. As a result, they are typically used for continuous, base-loaded operations. Combustion turbines and hydropower are much more flexible and are typically used to respond to peak energy demand.Hydro stations have much lower operating costs than steam-thermal or combustion turbines, primarily thanks to zero fuel costs. However, h