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The paper describes a control method, to be used in conjunction with wide-area measurement system (WAMS), to damp the very low frequency interarea modes of very large power systems from only a limited number of power stations. It requires knowledge of the eigenvectors of the targeted modes only. The other modes are not destabilized. Results from numerical simulations and eigenvalue evaluations are given. Index Terms--Damping slow oscillation modes, Eigen analysis, Eigen properties, interarea oscillations, power system stability, wide-area measurement system.

As wind power penetration increases and fossil plants are retired, it is feared that there will be insufficient kinetic energy (KE) from the plants to support the system frequency. This paper shows the fear is groundless because the high inertias (H [congruent to] 4 seconds) of wind turbine-generators (WTGs) can be integrated to provide frequency support during generation outage. Index Terms--Frequency control, stability, wind power generation.

In this paper, minute-to-minute wind power variations are decomposed into slow, fast, and ramp components to assess the influence of each component on power system operation. Using detailed, long-term simulation models, this paper confirms that most power systems can absorb the impacts of wind power variations with little difficulty. Yet, since ramps in wind power and system demand could coincide, systems with limited ramping capabilities are at risk. It is shown that extending simulation models to include load dynamics and automatic generation control (AGC) time delays do not alter these conclusions. This paper also discusses wind penetration approaches and control area performance measures, linking the latter to the placement of the wind farms within the interconnection. Index Terms--AGC model, automatic generation control (AGC), long-term dynamic model, penetration limit, system dynamic response, wind events, wind farm model, wind power.

Wind power fluctuations cause frequency deviation from the 60-Hz standard. Using the composite transfer function G (fw) of a small system of thermal power plants, it is estimated that power fluctuation of 5% of the total thermal plant capacity can be tolerated without exceeding 1% frequency deviation. The technology to filter out the power fluctuations by wind turbine generators for increasing wind power penetration already exists. However, perfect filtering sacrifices as much as 27.6% of the wind power that can otherwise be utilized. The paper presents a method of quantifying wind penetration based on the amount of fluctuating power that can be filtered by wind turbine generators and thermal plants. For optimal wind power acquisition, the penetration level is conservatively estimated to be 50%. Index Terms--Automatic generation control (AGC), Bode diagrams, filter, frequency fluctuation, power fluctuation, speed governors, steam turbines, thermal power plants, transfer function, wind farms, wind power penetration.

This paper shows that the capability of voltage-source converters (VSCs) to control the real power output of wind turbine generators (WTGs) can be applied to smooth power fluctuations due to wind turbulence. The paper calls attention to instability that can arise from: 1) the wind turbine itself and 2) the doubly fed induction generator (DFIG). The paper presents [G.sub.P/V] (s) to characterize the dynamic behavior of WTGs. Index Terms--Doubly fed induction generator (DFIG), decoupled P-Q control, filtering, frequency fluctuation, moment of inertia, smoothing, voltage-source converters (VSCs), wind farm, wind turbine generators (WTGs), wind power fluctuation.

Departing from aerodynamics (micromodel), the macromodel begins with the power output of a single wind turbine generator (WTG). The N units of WTGs in a wind farm are characterized by the time delays it takes wind, at average velocity, to traverse the distances separating them. Predictions from simulations are in agreement with recorded wind farm data. Smoothing of high-frequency power components is by a factor close to [N.sub.-1/2]. Smoothing of low-frequency harmonic power components is small because the wind farm is limited in size. A theory, based on Fourier analysis, is presented to explain how the macromodel simultaneously copes with: 1) the high-frequency components of wind velocity (which have poor correlation) even for short distances and 2) the low-frequency components (which have some correlation). Index Terms--Correlated, frequency fluctuation, penetration, smoothing, spatial filtering, wind farm modeling, wind farms, wind turbine generators (WTGs), uncorrelated.

The concept of electrothermal coordination (ETC) in power system operation is proposed. ETC exploits thermal inertia to coordinate line temperature dynamics with existing system controls, thus increasing power transfer capability and enhancing system security and economic performance. This Part I begins with the theoretical basis of ETC and follows with an algorithm suitable for large-scale implementation in electricity markets, emphasizing that ETC can be readily integrated into existing software. The characteristics of ETC and its benefits in system operation are analyzed numerically in Part II through several case studies in power transfer capability, emergency load-shedding, congestion management, and system loadability. Index Terms--Day-ahead energy market clearing, electrothermal coordination, heat balance equation, line temperature dynamics, static and dynamic line thermal ratings.

As wind power penetration increases and fossil plants are retired, it is feared that there will be insufficient kinetic energy (KE) from the plants to support the system frequency. This paper shows the fear is groundless because the high inertias (H ≅ 4 seconds) of wind turbine-generators (WTGs) can be integrated to provide frequency support during generation outage. [ABSTRACT FROM AUTHOR]

Wind power fluctuations cause frequency deviation from the 60-Hz standard. Using the composite transfer function G (fw) of a small system of thermal power plants, it is estimated that power fluctuation of 5% of the total thermal plant capacity can be tolerated without exceeding 1% frequency deviation. The technology to filter out the power fluctuations by wind turbine generators for increasing wind power penetration already exists. However, perfect filtering sacrifices as much as 27.6% of the wind power that can otherwise be utilized. The paper presents a method of quantifying wind penetration based on the amount of fluctuating power that can be filtered by wind turbine generators and thermal plants. For optimal wind power acquisition, the penetration level is conservatively estimated to be 50%. [ABSTRACT FROM AUTHOR]

This paper shows that the capability of voltage-source converters (VSCs) to control the real power output of wind turbine generators (WTGs) can be applied to smooth power fluctuations due to wind turbulence. The paper calls attention to instability that can arise from: 1) the wind turbine itself and 2) the doubly fed induction generator (DFIG). The paper presents GP/V(s) to characterize the dynamic behavior of WTGs. [ABSTRACT FROM AUTHOR]

Departing from aerodynamics (micromodel), the macromodel begins with the power output of a single wind tur- bine generator (WTG). The N units of WTGs in a wind farm are characterized by the time delays it takes wind, at average velocity, to traverse the distances separating them. Predictions from simulations are in agreement with recorded wind farm data. Smoothing of high-frequency power components is by a factor close to N-½. Smoothing of low-frequency harmonic power components is small because the wind farm is limited in size. A theory, based on Fourier analysis, is presented to explain how the macromodel simultaneously copes with: 1) the high-frequency components of wind velocity (which have poor correlation) even for short distances and 2) the low-frequency components (which have some correlation). [ABSTRACT FROM AUTHOR]