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This paper presents the network frequency controlled by wind farm without supporting from other conventional power plants. The wind farm which consists of several wind turbines with doubly fed induction generators are divided into two groups and coordinated by a wind farm control center. The first group of wind turbines implements the kinetic energy control method, which can support fast frequency...
The introduction and penetration of non-conventional renewable energy based generation technologies in South Africa and the world over has increased grid connection complexities. This has resulted in strict grid code requirements by utilities in order to ensure a reliable, safe and economically manageable grid operation. This justifies the need for adequate system models to represent overall system...
Power curve provided by wind generator manufacturer, which characterizes the steady-state operation condition of wind generating set, has deviation when it is used to analyze the real operating condition of wind generation set. This paper conducts the calibration of power curve of wind-driven generator and builds the forecasting model of wind power based on least squares support vector machine (LS-SVM)...
One of the challenges in future energy systems is the massive use of high power converters that decouple new energy sources from the AC power grid, disabling natural frequency response. This situation decreases the total system inertia affecting the ability of power system to overcome system frequency's disturbances. It has been established by the wind power industry a controller to enable inertial...
Integrating additional wind energy into the existing power system may cause wind curtailment due to the system operational constraints and reliability requirements. Effective ways to mitigate this problem are to use energy storage or increase transmission capacity. In this paper, the impacts of coordinating with pumped storage and increasing transmission capacity on wind output curtailment mitigation...
Traditional methods of planning investment in Wind Energy Conversion Systems (WECS) focus on selecting sites that individually display the maximum total extractable wind energy. However, cost penalties associated with the uncertainty in Wind Power Production (WPP) may be non-negligible. This paper proposes a more holistic methodology to find the near optimal investment in WECS considering capital...
It is an important but challenging issue to represent a wind farm using an equivalent model. This paper tries to find a practical clustering method of a doubly-fed induction generator (DFIG) wind farm for power system simulation. In the paper, the equivalent wind speed for the equivalent model is calculated according to the relationship between power and wind speed. The operating status of DFIG are...
Under high penetration of wind and solar, the power system is facing the challenge to maintain the balance between generation and load due to the insufficient ramping capability. To resolve this challenge, a new market mechanism was proposed by many ISOs to add the flexible ramping constraints or flexible ramping product to maintain the ramping flexibility in addressing net load uncertainty and variability...
This paper studies the feasibility of utilizing the reactive power of grid-connected variable-speed wind generators to enhance the steady-state voltage stability margin of the system. Allowing wind generators to work at maximum reactive power limit may cause the system to operate near the steady-state stability limit, which is undesirable. This necessitates proper coordination of reactive power output...
Wind turbines play an important role in producing clean energy and reducing pollution, but they can fail during the operation due to various types of faults and environment uncertainties. Therefore, one of the key problems in wind energy systems is the resilient control to achieve their high reliability. To reach this goal, we first design a resilient controller by incorporating faults into the wind...
The short circuit contribution of a Type 3 wind farm connected to a series compensated line is affected by subsynchronous interactions making it essential to model such behavior. Fundamental frequency models are unable to represent the majority of critical wind generator fault characteristics. The complete electromagnetic transient (EMT) models, though accurate, demand high levels of computation and...
Variable-speed wind generators (VSWGs) are being extensively deployed as the main wind power generation technology around the world. However, when the VSWGs are integrated to gas turbine based (e.g. combined-cycle gas turbines (CCGTs) and open-cycle gas turbines (OCGTs)) electricity networks, potentially threatening dynamic interactions could occur during frequency excursions. This is due to the fact...
Electricity markets contain many uncertainties such as changes in generation and demand levels. Especially with increasing integration of wind power, uncertainties in generation availability have increased. This increases the network access risk for generators. Therefore, the need for a reliability mechanism for generators has emerged. Firm transmission access is a transmission reliability mechanism...
This paper presents a model-based control technique to provide the contribution of wind power generators to primary frequency regulation in electric power systems. Models of individual wind power generators and wind farm (WF) as a whole are presented and the proposed control strategy is detailed. It consists of a central controller, a central Kalman filter (KF), and some local KFs, one for each wind...
For the stable integration of wind power plants into power system, system operators legislate the integration standards and operating strategies for each wind power plants. Especially, with the connection of large scale wind power plant such as Off-shore wind farm, the plants obligate to support the reactive power during the fault by using PCS(Power Conversion System) control. This paper proposes...
A predictive decision support algorithm for power systems with a high share of renewable generation is presented. We consider a scenario where, e.g. within 1 hour, the renewable share is first gradually increased and compensated by secondary reserve. Then, a sudden disconnection of one or several wind farms occurs, e.g., because of violated fault ride through requirements. This disconnection has to...
The optimal bidding strategy for trading electricity from a wind farm is not always clear. This paper outlines a method for predicting whether the market will be long or short and uses this information to select the best quantile regression for the current market conditions. Results from a simulation with a 2.5MW turbine produced a savings of over £1000 over a three month period compared to using...
This paper proposes algorithms for optimal siting and sizing of Energy Storage System (ESS) for the operation planning of power systems with large scale wind power integration. The ESS in this study aims to mitigate the wind power fluctuations during the interval between two rolling Economic Dispatches (EDs) in order to maintain generation-load balance. The charging and discharging of ESS is optimized...
This paper proposes a method to consider the impact of the wind farms maximum current limits on real-time voltage stability assessment. The approach is based in a multi-port equivalent of the system which makes possible to assess the effect of each wind farm limit on the stability boundary, the approach indicates the distance to the limit activation and the effect of each load in such a limit. The...
This paper proposes a simplified but fast approach based on a Norton equivalent of wind generators to detect undervoltage tripping of wind generators. This approach is successfully applied to a real wind farm. Today, most grid codes require the wind farm to withstand a voltage dip of 0% retained voltage. The ability of the wind generators to raise the voltages supplying reactive current and to avoid...
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