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System Protection Schemes (SPS) have the potential to greatly enhance the utilization of the network, often by automatically disconnecting generators in response to contingency events. However, malfunctions of such systems may expose the system to harmful blackouts. The operation of unreliable SPS is therefore subject to a cost-benefit balance between the benefits of increased system utilization and...
This paper proposes an application of a hierarchical automatic voltage regulation scheme for wind power plants connected to HV networks. The proposed control schemes is based on a given topology of wind power plants. In particular, we assume that wind generators are connected to each other and have a unique point of contact at the HV level. The secondary voltage control scheme proposed in the paper...
This paper aims to compare the effect of wind energy penetration on electricity prices by considering different levels of installed wind capacities. The market clearing problem is formulated as a two stage stochastic optimization problem, where the first stage represents the clearing of the market with scheduled wind production and the second stage models the balancing market operations with different...
Deregulation of power system brought huge competition among the sellers and buyers of electricity market where all the parties try to gain their profit, hence it is quite important for grid or independent system operator (ISO) to maintain smooth flow of electric power without violating its security level and satisfies customers with reasonable cost. Power system transmission congestion occurs due...
Though a lot of research is reported on the transmission expansion planning (TEP), few have considered the impact of wind sources with varying penetration. Inadequate transmission capacities can result in spillage of the wind power. This has implications on loss of load and higher cost of generation. The proposed methodology formulates an integrated approach to TEP, which optimizes cost of new lines,...
In the past few years, the penetration of wind energy to the grid has been drastically increased. However, the variable nature of wind speed has an impact on power quality. Therefore, the voltage and reactive power control are necessary in a grid connected wind farms due to stochastic nature of wind speed. The wind connected system may consist of large number of voltage controllers i.e. on-load tap...
The paper describes the dynamic behavior of the wind power plants and shows simulation results. The operation principle of the the double fed induction wind generator will be presented. The simulations were made with a Euro stag modeled version using a part of the National Power System Euro stag database. Various operation scenarios were simulated to show the impact in the transmission power grid.
A wind farm often consists of a number of wind turbines (WTs) operating simultaneously, which not only challenges the operation of the wind farm but makes the condition monitoring (CM) more costly than ever before if each turbine is equipped with a standard commercially available WT CM system (e.g. SKF's WindCon system). With the continual increase of wind farm size, the operator is under increasing...
Large scale megawatt wind farms like the Adama wind farm and Ashegoda is being integrated into the Ethiopian Electric Power System. The location of Adama wind farm is about 95 km from Addis Ababa (the capital city of Ethiopia) and 3km from Adama town, with an altitude elevation of 1824∼1976m. The central geographical position of the wind farm is 39°13′48″E, 8°32′41″N. The Adama wind farm has two parts...
This paper considers market operation of an energy storage unit. The goal is to assess the potentials for revenue and impact of a profit-maximizing storage unit on market prices in the day-ahead electricity market. It also analyzes the impact of a storage unit on market performance of conventional generators. A bilevel profit maximization model is proposed in which the upper-level problem is a storage...
This paper investigates the effect of harmonics due to renewable generation, energy-saving home appliances and electric vehicle chargers. Harmonics were found to be contained at the transmission level due to the presence of shunt capacitors. These shunt capacitors behave like single-tuned or high-pass harmonic filters, however there will be an increased risk of harmonic resonance making the transmission...
With the increase of wind power penetration, the impact of wind power ramp event on power system becomes more and more serious. To assess the impact of it on power system, the characteristic and development process of wind power ramp event is analyzed, and a time-dependent outage model of conventional generators which is appropriate to wind power ramp event is constructed base on Monte-Carlo method...
Available Transfer Capability (ATC) of power system with large farms is influenced by many factors. These factors include wind farms output, load and generators output that they are uncertain and have statistical characteristics. This paper studies the feasibility and effectiveness of prediction ATC through Multivariable Linear Regression Models (MLRM). And the system which considering transmission...
This paper succeeds in solving the optimal reactive power dispatch (ORPD) of power system where the units contains wind turbines. Two types of wind turbine are taken into account in the ORPD, and they are the variable speed wind turbine (VSWT) and the fixed speed wind turbine (FSWT). Besides, the primal dual interior point method is introduced to serve as the algorithm to solve ORPD, since it performs...
Two smart frequency control schemes are presented in this paper. The first one is an adaptive under-frequency load shedding (UFLS) scheme, and the second one is system frequency control scheme based on energy storage and wind farm. The UFLS is developed based on a new and simplified methodology for an estimation of the magnitudes of disturbances (EMD). Using the estimation results, the UFLS can be...
Increase in the market share of wind energy in total electricity generation and its impact to power grid has imposed new challenges to the stability of each wind turbine generator (WTG) unit. In the case of power undersupply, the problem on voltage stability and voltage collapse will eventually occur. In this paper, the impact of reactive power control in improving the performance of squirrel cage...
This paper analyses the frequency characteristic of the power system and apply the result to wind farm output smoothing control, which uses the inertial energy of wind power generators and is designed based on a notch filter. It is concluded that the proposed method can control the frequency variations of the power system due to wind generators with small power loss.
The goal of the U.S. Department of Energy (DOE) roadmap [1] is a 20% penetration of wind energy into the generation mix by 2030. Attaining this objective will help protect the environment and reduce fossil fuel dependency, thus improving energy security and independence. This paper discusses how the technology used in large scale offshore wind farms impacts voltage regulation in distribution feeders...
This paper presents the characteristics analysis of wind farm to the participation of power grid frequency regulation. Wind farm is built by equivalent modeling method, and contains full-converter wind turbine generators (WTG) with Wind Turbine of Direct-Drive Permanent Magnet Synchronous Generator (DDPMSG). At first, model and control strategy of WTG with PMSG is introduced. Then single-machine equivalent...
When large wind farms are integrated to grid a complete power flow and dynamic study is necessary to identify the most probable problems and to develop methods to mitigate them. Wind farms are usually spread over a wide area and has many wind generators, which produce varying active power as they are exposed to different wind patterns. Most wind power systems are based in remote rural locations and...
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