Analysis on the Fluctuation of Wind Power

2015 ◽  
Vol 733 ◽  
pp. 199-202
Author(s):  
Rui Hao Wang

This paper is aimed at exploring the characteristic fluctuation of wind power based on samples from a certain wind farm. First, the paper is to analyze fluctuations of wind power at different time scales. According to a sliding difference algorithm to build wind power fluctuations evaluation. Wind power fluctuation index for different time scales are used to fit probability distributions, indicating that the best form of distribution of wind power fluctuations is t location scale distribution. Secondly, considering the wind power has the characteristics of non-linear, non-stationary signal of the data, it fully meets the wavelet neural network analysis of the characteristics of the data. Therefore, select wavelet neural network training and testing so as to make predictions about the future of the total power of wind farm. It points out the differences between different regions covered by the index from the fluctuation characteristics of wind power, thus further understanding the fluctuation characteristics of wind power: Influenced by the time and space distribution and other factors, there is a big difference between the output power fluctuation characteristics of single wind generator and wind farm, which is because of the different wind machine in the field by the wind energy differences, and the wake effect of organic groups, making frequent fluctuations in power distribution; the fluctuation of wind is gentle, i.e. with increasing spatial distribution scale, so gentle effect occurs to wind power fluctuations. Finally, through the analysis of the fluctuation characteristics of power, power factor and analyses the influence of the characteristics of fluctuation, the paper draws a conclusion of the following improvement programs to overcome the adverse effects of wind power fluctuation of power grid operation: the rational allocation of energy storage devices, expanding the coverage area of a wind farm, or improving the design of the windmill, which will make wind farms adapt to different wind directions, thus eliminating the impact of fluctuations on the power grid from the wind farm power output by the energy storage device, and covering the area of large wind farms can adapt to different wind directions, and with power complementary, it has achieved the amount of stable power transmission into the grid.

2012 ◽  
Vol 608-609 ◽  
pp. 487-493 ◽  
Author(s):  
Zuo Xia Xing ◽  
Guan Feng Zhang ◽  
Jin Song Liu ◽  
Xing Jia Yao

Since distributed power generation equipment such as wind power contain electric power fluctuation connected into the power grid, hybrid energy storage (HESS) equipment for power compensation is used to solve the problems of reliability and operation of the utility power grid. Constant power control and Fuzzy-Rules-based control of AC-DC and BESS is proposed for smoothing the random wind power fluctuations, considering the operating constraints of the HESS, such as state of charge (SOC) and wind power (Pout). The simulation is accomplished by using a 9MW wind farm and the HESS in Matlab, The results show that by the proposed control methods of the bi-directional DC-DC converter and the DC-AC converter, the energy storage system can smooth the wind power outputs and provide reactive power support to the grid.


2013 ◽  
Vol 448-453 ◽  
pp. 2866-2871 ◽  
Author(s):  
Jun Hui Li ◽  
Xing Xu Zhu ◽  
Gan Gui Yan ◽  
Gang Mu ◽  
Wei Hua Luo

This paper designs a grouping energy management strategy to reduce the influence of wind power fluctuations on the power system. To improve operational technicality and economy of energy storage stations, this paper designs a grouping energy management strategy with SOC correction. According to physical constrains of battery energy storage systems, technical and economic evaluation index of energy storage stations are established. Reasonable limit bands to an energy storage station installed 5MW×2h can balance the output power of a wind farm installed 49.3MW achieved through example analysis. Then the energy management strategy designed is proved to be able to control the change range of the battery SOC and distribute control tasks efficaciously, improving operational technicality and economy of the station effectively. This research provides a theoretical reference to design of energy management strategies for energy storage stations installed small at wind farms.


Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3393 ◽  
Author(s):  
Pingping Yun ◽  
Yongfeng Ren ◽  
Yu Xue

Wind power penetration ratios of power grids have increased in recent years; thus, deteriorating power grid stability caused by wind power fluctuation has caused widespread concern. At present, configuring an energy storage system with corresponding capacity at the grid connection point of a large-scale wind farm is an effective solution that improves wind power dispatchability, suppresses potential fluctuations, and reduces power grid operation risks. Based on the traditional energy-storage battery dispatching scheme, in this study, a multi-objective hybrid optimization model for joint wind-farm and energy-storage operation is designed. The impact of two new aspects, the energy-storage battery output and wind-power future output, on the current energy storage operation are considered. Wind-power future output assessment is performed using a wind-power-based Markov prediction model. The particle swarm optimization algorithm is used to optimize the wind-storage grid-connected power in real time, to develop an optimal operation strategy for an energy storage battery. Simulations incorporating typical daily wind power data from a several-hundred-megawatt wind farm and rolling optimization of the energy storage output reveal that the proposed method can reduce the grid-connected wind power fluctuation, the probability of overcharge and over-discharge of the stored energy, and the energy storage dead time. For the same smoothing performance, the proposed method can reduce the energy storage capacity and improve the economic efficiency of the wind-storage joint operation.


2020 ◽  
Vol 17 (12) ◽  
pp. 5307-5314
Author(s):  
L. Sarojini ◽  
R. Supraja ◽  
V. Hamsadhwani ◽  
M. Sathiskumar

Limited fossil fuel resources and current environmental considerations have created wind energy as the best alternative for spotless renewable source of energy, to replace the conventional sources of energy. The Wind power production has quite a few drawbacks owing in the direction of the methods used in harnessing wind energy. This paper focuses on the method that decreases the effect of the voltage variability within the grid initiated through uncontrollable imprudent power flow and the output power fluctuation within the grid. This paper gives solution to diminish the fluctuation that creates unstable voltage across the line by installing such an energy storage device. Reactive power compensation has been mutually implemented to manage the distribution of the reactive power supply across wind farm based power networking through internal Static Synchronous Compensator (STATCOM). Here, bidirectional interleaved DC/DC-converters and double layer electrical capacitors are used. Therefore the introduction of two different systems, the energy storage systems with interleaved boost unit along with the reactive power mitigation for giant wind farms was implemented by integrating them into single system to check and review the wind power plant stability management.


2013 ◽  
Vol 860-863 ◽  
pp. 1909-1913
Author(s):  
Hai Xiang Xu ◽  
Peng Wang ◽  
Xiao Meng Ren

At present, the technology of wind power forecasting isn‘t mature enough in china, so some grid-connected wind farms will be assessed when theirs power forecasting accuracy cant reach the assessment standard. In response to the situation, combined with the characteristics of WPSPS and wind farms, this paper designs a service mechanism that WPSPS help wind farms tracking generation schedule curve, namely, encouraging WPSPS to supply output compensation service for wind farm by market means to increase the accuracy of wind power forecasting. By this mechanism, not only WPSPS and wind farms will achieve win-win, but also the impact on the grid caused by fluctuations of wind powers output will reduce.


2014 ◽  
Vol 536-537 ◽  
pp. 470-475
Author(s):  
Ye Chen

Due to the features of being fluctuant, intermittent, and stochastic of wind power, interconnection of large capacity wind farms with the power grid will bring about impact on the safety and stability of power systems. Based on the real-time wind power data, wind power prediction model using Elman neural network is proposed. At the same time in order to overcome the disadvantages of the Elman neural network for easily fall into local minimum and slow convergence speed, this paper put forward using the GA algorithm to optimize the weight and threshold of Elman neural network. Through the analysis of the measured data of one wind farm, shows that the forecasting method can improve the accuracy of the wind power prediction, so it has great practical value.


Author(s):  
Junrong Xia ◽  
Pan Zhao ◽  
Yiping Dai

Due to the intermittence and fluctuation of wind resource, the integration of large wind farms in a power grid introduces an additional stochastic component to power system scheduling. This always brings challenges to maintain the stability of power system. Integrating gas turbine units with wind farms can compensate their output fluctuation. In this paper, a methodology for the operation scheduling of a hybrid power system that consists of a large wind farm and gas turbine units is presented. A statistical model based on numerical weather prediction is used to forecast power output of the wind farm for the next 24 hours at quarter-hour intervals. Forecasts of wind power are used for optimizing the operation scheduling. In order to study the dynamic performance of the proposed hybrid power system, dynamic modeling of this hybrid power system is addressed. Wind farm and gas turbine units are integrated through an AC bus, and then connected to a power grid. An aggregated model of the wind farm and detailed models of gas turbine units are developed, and are implemented using MATLAB/Simulink. Simulation studies are carried out to evaluate the system performance using real weather data. The simulation results show that the proposed hybrid power system can compensate fluctuating wind power effectively and make wind power more reliable.


2013 ◽  
Vol 380-384 ◽  
pp. 3370-3373 ◽  
Author(s):  
Li Yang Liu ◽  
Jun Ji Wu ◽  
Shao Liang Meng

With the massive development and application of wind energy, wind power is having an increasing proportion in power grid. The changes of the wind speed in a wind farm will lead to fluctuations in the power output which would affect the stable operation of the power grid. Therefore the research of the characteristics of wind speed has become a hot topic in the field of wind energy. In the paper, the wind speed at the wind farm was simulated in a combination of wind speeds by which wind speed was decomposed of four components including basic wind, gust wind, stochastic wind and gradient wind which denote the regularity, the mutability, the gradual change and the randomness of a natural wind respectively. The model is able to reflect the characteristics of a real wind, easy for engineering simulation and can also estimate the wind energy of a wind farm through the wind speed and wake effect model. This paper has directive significance in the estimation of wind resource and the layout of wind turbines in wind farms.


Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1067
Author(s):  
Youming Cai ◽  
Zheng Li ◽  
Xu Cai

It is important to reduce the impact of the high penetration of wind power into the electricity supply for the purposes of the security and stability of the power grid. As such, the inertia capability of wind farms has become an observation index. The existing control modes cannot guarantee the wind turbine to respond to the frequency variation of the grid, hence, it may lead to frequency instability as the penetration of wind power gets much higher. For the stability of the power grid, a simple and applicable method is to realize inertia response by controlling wind farms based on a high-speed communication network. Thus, with the consideration of the inertia released by a wind turbine at its different operating points, the inertia control mechanism of a doubly-fed wind turbine is analyzed firstly in this paper. The optimal exit point of inertia control is discussed. Then, an active power control strategy for wind farms is proposed to reserve the maximum inertia under a given power output constraint. Furthermore, turbines in a wind farm are grouped depending on their inertia capabilities, and a wind farm inertia control strategy for reasonable extraction of inertia is then presented. Finally, the effectiveness of the proposed control strategy is verified by simulation on the RT-LAB (11.3.3, OPAL-RT TECHNOLOGIES, Montreal, Quebec, Canada) platform with detailed models of the wind farm.


2014 ◽  
Vol 687-691 ◽  
pp. 3502-3507
Author(s):  
Wu Chang Dai ◽  
Yu Dong ◽  
Xin Fei Zhao ◽  
Xian Jun Shang

In order to remedy errors in wind power prediction, a common method adopted in wind farms is the configuration of a certain capacity of energy storage at the grid interface. The traditional approach for configuring capacity ignores the problems of excessive allocation and the adjustment of SOC, and for this reason, the paper proposes a model of wind power coupling by adding a resistance load at the grid connection point. In addition, this paper proposes a control strategy to improve the operation of energy storage systems through the adjustment of SOC in order to maintain a high level of SOC, and proposes a new approach to deploying storage capacity based on this. According to the analysis of a wind farm in Northeast China, a new approach to the configuration of the energy storage can use local utility of a little electrical energy to reduce the allocated capacity, and furthermore, this method also has better control characteristics.


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