Demand Response and Wind Power Ramp Limitation for Reducing Frequency Excursions in Power Systems with High Wind Penetration

摘要

Traditionally, the grid frequency Is controlled by conventional power plants in most of developed countries. The main goal of this control is to keep the frequency within specified limits depending on each Grid Code. The conventional generators are usually equipped with so-called primary and secondary control, and the inertia in the power system grid limits the rate of frequency change in case of imbalance between supply and demand power. This power imbalance has to be catered by the generation, since demand-side is generally considered as not controllable. In recent years, the rapid development of wind turbine technology and the increasing wind power penetration have resulted in a continuous reformulation of wind power requirements. Some Transmission System Operators have unified requirements and connection rules for all production units, which makes it very difficult for wind turbine producers and wind farm developers to fulfill these modified Grid Codes. Moreover, the primary source for wind turbines is not controllable and the frequency control problem emerges as a relevant issue, specially in countries with high wind energy penetration. Indeed, wind power fluctuations may produce significative frequency excursions. Under such conditions, some authors suggest the participation from the demand-side as an additional contribution to maintain the power system stability. With this aim, this paper is focused on studying power imbalances in high wind energy penetration power systems considering frequency-sensitive demand responses. Power fluctuations due to the wind stochastic nature as well as different conventional power plants regulation strategies, combined with demand-side contribution and wind power positive ramp limitation technique are compared and included in the paper.