Stability Assessment of Power System Models For Higher Wind Penetration
01 Oct 2008-pp 1-5
TL;DR: In this article, variable frequency transformers (VFTs) were proposed as an effective means of interconnecting synchronous or asynchronous regions to enhance wind penetration, and the steady state stability limits of the system were improved with VFT as inter connectors.
Abstract: For grids of low X/R ratios voltage control through active power is effective in reducing the voltage at the point of interconnection of wind farms to grid Active power voltage control can be achieved using energy storage schemes or inter connectors In this paper we propose variable frequency transformers (VFT) as an effective means of interconnecting synchronous or asynchronous regions to enhance wind penetration It is shown that the steady state stability limits of the system are improved with VFT as inter connectors Also the performance of the VFT under open circuit and short circuit conditions are evaluated
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10 Apr 2013
TL;DR: The Variable Frequency Transformer (VFT) as mentioned in this paper is a controllable, bidirectional transmission device that can transfer power in between asynchronous power system networks, where the two separate electrical networks are connected to the stator winding and the rotor winding, respectively.
Abstract: The Variable Frequency Transformer (VFT) is basically a controllable, bidirectional transmission device that can transfer power in-between asynchronous power system networks. The construction of VFT is similar to conventional asynchronous machines, where the two separate electrical networks are connected to the stator winding and the rotor winding, respectively. One power system is connected with the rotor side of the VFT and another power system is connected with the stator side of the VFT. The electrical power is exchanged between the two networks by magnetic coupling through the air gap of the VFT and both are electrically isolated. This paper gives an overview about core components, commissioning, mechanical design, model, operation, analysis and applications of VFT.
6 citations
Cites background from "Stability Assessment of Power Syste..."
...d) Asynchronous inter connector for increasing the wind integration [27] – [28]....
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TL;DR: In this article , a critical review of variable frequency transformers (VFTs) depicting its sustainable development for power system interconnection is presented and the possible gaps for incorporation of VFT in power systems that have not been reported in literature are identified.
1 citations
References
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01 Oct 2006
TL;DR: In this paper, the impact of wind power integration on the voltage stability of the power system was investigated and different impacts of integrating wind farms based on different wind turbines technologies were illustrated.
Abstract: In some regional grids in China, wind power penetration will increase rapidly because of the abundant wind resources in those areas and the government policy impetus. However, the power system security and stability may be affected due to the higher wind power penetration. Because majority of the wind farms with higher installed capacity intends to be connected into the transmission network of 220 kV voltage level, their impacts are becoming more widespread. In the grid impact studies of wind power integration, voltage stability is the mostly concerned problem that will affect the operation and security of wind farms and power grid. In this paper, the detailed wind turbines steady-state model and dynamic model are used to explore the wind power integration impact on voltage stability of the power system; the load flow calculation (P-V curve and V-Q curve) and dynamic contingency study are conducted; the different impacts on voltage stability of integrating wind farms based on different wind turbines technologies are illustrated and the following conclusions are presented: a. Wind turbines equipped with simple induction generator are not provided with reactive power regulation capability. Voltage stability deterioration is mainly due to the large amount of reactive power absorbed by the wind turbine generators during the continuous operation and system contingencies. b. Wind turbines equipped with doubly fed induction generator (DFIG) controlled by the PWM converters are provided with reactive power regulation capability; can absorb or supply reactive power during normal operation. The adverse affect on local network voltage stability is mitigated so that more wind power installed capacity can be incorporated into the grid. c. The transient voltage stability characteristics of wind turbines with DFIG are better than wind turbines with induction generator because of the voltage control capability of the DFIG based wind turbines; The DFIG based wind turbines have a better voltage recovery performance than the IG based wind turbines with same rating.
91 citations
"Stability Assessment of Power Syste..." refers background in this paper
...But as the real power output increases beyond a critical value, the voltage will begin to decrease fast and subsequently collapse [12]....
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TL;DR: In this article, the authors discuss the power electronic and energy storage technologies used in wind power, and discuss the technologies that make wind power more palatable to grid operators, making it possible for engineers to finally harness wind energy's tremendous potential in wind-swept, remote locales.
Abstract: Power electronics and exotic energy storage devices are making wind power steady enough to compete with conventional electricity sources. Systems based on advanced power electronics and energy storage devices are massaging and managing power flows from wind turbines, enabling them to contribute to electricity grids without putting those grids at risk. Not only are the technologies making wind power more palatable to grid operators, they are even making it possible for engineers to finally harness wind energy's tremendous potential in wind-swept, remote locales. This article discusses the power electronic and energy storage technologies used in wind power.
61 citations
24 Jun 2007
TL;DR: In this paper, four alternatives for large-scale wind power integration in power systems with transmission bottlenecks are considered: revision of the methods for calculation of available transmission capacity, transmission network reinforcement, excess wind energy curtailments and extra wind energy storage in hydro reservoirs.
Abstract: The best conditions for the development of wind farms are in remote, open areas with low population density. The transmission system in such areas might not be dimensioned to accommodate additional large-scale power infeed. Furthermore a part of the existing transmission capacity might already be reserved for conventional power plants situated in the same area. In this paper four alternatives for large-scale wind power integration in power systems with transmission bottlenecks are considered: revision of the methods for calculation of available transmission capacity, transmission network reinforcement, excess wind energy curtailments and excess wind energy storage in hydro reservoirs. The paper provides a discussion on each of the four aforementioned alternatives based on the existing research.
57 citations
"Stability Assessment of Power Syste..." refers background in this paper
...Fig. 5 .Simulation results for an opencircuit fault atarea2....
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...Therelevant simulation results aregiven inFig. 5 . Voltage remains almost unchanged andthemagnitude of current inarea 1 isdetermined bytheequivalent circuit parameters ofthestator side during theperiod ofopen circuit....
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10 Jun 2004
TL;DR: In this article, the authors discussed how a sustainable energy supply based on off-shore wind power and pumped storage, called a "wind and water"-model, might look, and it turns out that such an energy scheme, while feasible in principle, would require an immense storage capacity which would be impossible to realize.
Abstract: Sustainability of the future energy supply based on renewable resources is a long-term strategic objective in view of limited fossil resources and avoidance of emissions and toxic waste. Of the various resources, available now or in future, wind is presently considered in Europe to hold most promise in the next few decades for contributing a sizable part of the electrical energy; generating electricity from wind is state of the art and feeding large amounts of wind power to the electrical grid is believed by many to be unproblematic. With recent data from one of the four control areas in Germany it is discussed how a sustainable energy supply based on off-shore wind power and pumped storage, called a "wind and water"-model, might look. It turns out that such an energy scheme, while feasible in principle, would require an immense storage capacity which would be impossible to realize. Thermal generation continues to be needed, based on various energy carriers, among them biomass according to availability
54 citations
01 May 2005
TL;DR: In this article, a sequential Monte Carlo simulation method for incorporating energy storage capability in generating capacity adequacy evaluation of renewable energy based power systems is described. But, the authors do not consider the impact of energy storage on power system reliability performance.
Abstract: Energy storage is an important feature in renewable energy based power systems especially in small isolated applications. This paper describes a sequential Monte Carlo simulation method for incorporating energy storage capability in generating capacity adequacy evaluation of such systems. Time series models were used to simulate the generation/load characteristics of a power system. Energy storage state time series were obtained from the load time series and the available generation time series and incorporated in the overall system adequacy evaluation. The impact of energy storage on power system reliability performance is investigated using example systems containing wind energy and/or solar energy
50 citations