共查询到14条相似文献,搜索用时 54 毫秒
2.
3.
一种基于全闭环实时数字物理仿真的
次同步振荡阻尼控制 总被引:2,自引:0,他引:2
为解决呼盟系统火电机组存在的次同步振荡问题,提出一种基于静止无功补偿器的次同步振荡阻尼控制。采用RTDS实时仿真工具与实际系统控制器搭建全闭环实时数字物理仿真平台,实现验证控制策略、优化控制参数及检验控制器有效性等工作。通过频率扫描法仿真实验寻找次同步振荡中心频率,大扰动仿真实验表明,静止无功补偿器能有效抑制火电机组轴系次同步振荡,验证了控制策略正确性及可行性,为现场调试提供指导。 相似文献
4.
在物理模拟实验中对水合物微观赋存模式和饱和度进行准确控制和评价尚存在技术困难,仅依赖实验技术研究含水合物沉积物声学特性、建立储层参数解释模型存在局限性。采用基于有限元的数字岩石物理技术,针对悬浮、接触和胶结三种典型的水合物微观赋存模式分别建立多孔介质的三维电-力-声多物理场耦合模型,考察了微观赋存模式和水合物饱和度对多孔介质声速和衰减的影响规律,对比了声速数值模拟与理论模型计算结果,建立了声波衰减参数与水合物饱和度之间的关系式。研究结果表明:(1)对于三种水合物赋存模式,由于水合物相比孔隙水具有更高的弹性模量,多孔介质的声速随着水合物饱和度的增大而增大;水合物的存在导致声波在传播过程中遇到更多不连续的声阻抗界面,声衰减随着水合物饱和度的增大而近似线性增大;(2)悬浮和接触赋存模式条件下,水合物饱和度对多孔介质的声速和衰减影响规律基本一致;对于相同的水合物饱和度,胶结模式条件下含水合物多孔介质具有更高的声速和更小的声衰减;(3)通过合理选择参数值,利用权重方程与Lee改进的Biot-Gassmann Theory(BGTL)模型估算的含悬浮和接触模式水合物多孔介质的声速较为准确;通过等效... 相似文献
5.
6.
7.
介绍了变频调速的节能原理和节能效果。叙述了煤矿主通风机使用闭环变频器自动控制系统和节能改造的设计思路。指出,“合理”使用闭环频率自动控制系统,可节约更多的能量。 相似文献
8.
E. A. Bossanyi 《风能》2000,3(3):149-163
This article reviews the design of algorithms for wind turbine pitch control and also for generator torque control in the case of variable speed turbines. Some recent and possible future developments are discussed. Although pitch control is used primarily to limit power in high winds, it also has a significant effect on various loads. Particularly as turbines become larger, there is increasing interest in designing controllers to mitigate loads as far as possible. Torque control in variable speed turbines is used primarily to maximize energy capture below rated wind speed and to limit the torque above rated. Once again there are opportunities for designing these controllers so as to mitigate certain loads. In addition to improving the design of the control algorithms, it is also possible to use additional sensors to help the controller to achieve its objectives more effectively. The use of additional actuators in the form of individual pitch controllers for each blade is also discussed. It is important to be able to quantify the benefits of any new controller. Although computer simulations are useful, field trials are also vital. The variability of the real wind means that particular care is needed in the design of the trials. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
9.
The authors show that: (a) with reliable prediction of low variance in the wind velocity, modern wind farms have the wherewithal to produce regulated power in the next hour; (b) when the conditions for producing regulated power are not predicted, the wind farms may opt to use the tracking mode which tracks the slowly time-varying, non-turbulent component of wind power and (c) the proposed control system has the capability to divert some of the wind farm power to implement dynamic performance enhancement strategies, for system damping. The capabilities are demonstrated by simulations of a wind farm made up of 24 windturbine generators using one-hour-long wind velocity data. 相似文献
10.
11.
12.
13.
An optimization framework for global optimization of the cable layout topology for offshore wind farm (OWF) is presented. The framework designs and compares closed-loop and radial layouts for the collection system of OWFs. For the former, a two-stage stochastic optimization program based on a mixed integer linear programming (MILP) model is developed, while for the latter, a hop-indexed full binary model is used. The purpose of the framework is to provide a common base for assessing both designs economically, using the same underlying contingency treatment. A discrete Markov model is implemented for calculating the cable failure probability, useful for estimating the time under contingency for multiple power generation scenarios. The objective function supports simultaneous optimization of (i) initial investment (network topology and cable sizing), (ii) total electrical power loss costs and (iii) operation costs due to energy curtailment from cable failures. Constraints are added accounting for common engineering aspects. The applicability of the full method is demonstrated by tackling three differently sized real-world OWFs. Results show that (i) the profitability of either topology type depends strongly on the project size and wind turbine rating. Closed loop may be a competitive solution for large-scale projects where large amounts of energy are potentially curtailed. (ii) The stochastic model presents low tractability to tackle large-scale instances, increasing the required computing time and memory resources. (iii) Strategies must be adopted in order to apply stochastic optimization for modern OWFs, intending analytically or numerically simplification of mathematical models. 相似文献