共查询到16条相似文献,搜索用时 156 毫秒
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为向电力需求侧管理的实施提供理论参考,采用PSASP仿真软件计算了系统中的7节点算例,分析了各节点的电压一功率灵敏度系数,基于灵敏度系数较高的节点电压易受负荷波动的影响、在负荷大量增加的时间段较易失稳的原则确定薄弱节点.结果表明,针对薄弱节点的灵敏度系数可在电力需求侧管理中确定无功补偿装置的安装位置,并可实现当负荷高峰来临前对薄弱节点的重点监测,或作为紧急态势下切除影响电网运行稳定的负荷节点的理论依据,从而改善电网运行能力. 相似文献
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双馈风电机组接入地区电网后的电压稳定分析 总被引:5,自引:5,他引:0
利用PSASP软件的UPI接口程序模块.在PSASP中建立了双馈风电机组模型,以两个实际的地区电网为例,研究双馈风电机组接入地区电网后对电网电压的影响,结果表明:双馈风电机组提高了地区电网的静态电压水平:双馈风电机组在故障后能够减少系统所需的无功储备,从而有利于地区电网的电压稳定;风速的波动对地区电网的电压有影响,但一般不会影响其暂态稳定性。 相似文献
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负荷模型的精确度对电力系统的潮流计算、电压稳定、频率稳定及长期动态过程的分析等都有很大的影响,在临界情况下,还有可能从根本上改变定性的结论。详细介绍了目前用于电力系统负荷建模的两个主要方法——统计综合法和总体测辨法,在对常用的负荷模型做概述的基础上,提出了定性和定量两类负荷模型的有效性评定方法,供负荷建模的准确性评定提供借鉴和参考。 相似文献
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谐波诺顿模型是一种非线性负荷模型,使用可编程交流电源构造不同电压类型(平坦波和尖顶波),且电压畸变率为5%获得PCC处电压和电流的波动量(两种不同运行状态下得到的谐波电压和谐波电流)。结果表明:居民单相非线性负荷诺顿模型参数不是恒定的,不同构造电压下获得的参数变化较大,且模型只在相同电压类型(平坦波或尖顶波)下才稳定些,大量实验及测试数据计算结果验证了这一结论。实验还表明:低压配电系统的电压波形是平坦波,这为构造居民单相非线性负荷诺顿模型提供了有利条件。 相似文献
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介绍了分布式光伏发电的原理,分别从削峰填谷作用、对低压配电网电压降的影响、系统节点电压及线路负载率的影响三个方面探讨了在智能电网中分布式光伏发电并网的可行性。通过理论分析和算例分析,得到了以下结论:分布式光伏发电系统并入智能电网可以对系统起到削峰填谷的作用,对电网的安全运行以及能源的充分利用发挥了重要作用;对低压配电网起到了提升电压、缓减压降的效果;降低了系统重载线路的负载率,且对系统的电压稳定性不会造成威胁。 相似文献
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It is well recognized that the voltage stability of a power system is affected by the load model and hence, to effectively analyze the reactive power compensation of an isolated hybrid wind-diesel based power system, the loads need to be considered along with the generators in a transient analysis. This paper gives a detailed mathematical modeling to compute the reactive power response with small voltage perturbation for composite load. The composite load is a combination of the static and dynamic load model. To develop this composite load model, the exponential load is used as a static load model and induction motors (IMs) are used as a dynamic load model. To analyze the dynamics of IM load, the fifth, third and first order model of IM are formulated and compared using differential equations solver in Matlab coding. Since the decentralized areas have many small consumers which may consist large numbers of IMs of small rating, it is not realistic to model either a single large rating unit or all small rating IMs together that are placed in the system. In place of using a single large rating IM, a group of motors are considered and then the aggregate model of IM is developed using the law of energy conservation. This aggregate model is used as a dynamic load model. For different simulation studies, especially in the area of voltage stability with reactive power compensation of an isolated hybrid power system, the transfer function of the composite load is required. The transfer function of the composite load is derived in this paper by successive derivation for the exponential model of static load and for the fifth and third order IM dynamic load model using state space model. 相似文献
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可控串联补偿器(TCSC)可以灵活地调节线路潮流,提高系统运行的稳定性,传统分析方法在评估TCSC提高系统静态电压稳定性作用时存在缺陷,无法考虑不确定性因素的影响。因此,建立计及TCSC接入的系统负荷裕度概率模型,考虑运行参数的随机波动,通过半不变量法和Gram-Charlier级数计算负荷裕度概率特征,进而得到电压失稳概率值。分别在常态与故障下对比TCSC安装前后的IEEE39节点系统失稳概率,结果表明,TCSC能有效地提高系统的静态电压稳定性,验证了本文方法的可行性与准确性。 相似文献
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短路故障是电网经常遇到故障。含风力发电系统的电网发生短路故障时,电网电压降低,这时如果不采取措施,风电场仍然从电网吸收无功,则会导致电网电压继续降低。采用风力发电系统的数学模型,分析了电网发生短路故障,比较了不采取保护和采取保护后发电机功角,电压以及频率的变化,采用PSASP仿真说明了采用减小风电场功率输入的方法可以使系统达到稳定。 相似文献
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This paper presents a cost-effective reactive power planning for active distribution networks based on a new index called reactive power loadability (Q-loadability). The impact of high renewable energy penetration on the static voltage stability of the system is analysed. The effect of load models in distributed generation planning is also demonstrated through nonlinear simulations. In order to ensure fast voltage recovery after a sudden disturbance, compensating devices are located using Q-loadability to increase the system voltage stability limit. Both static and dynamic analyses are carried out to determine the size of distribution static synchronous compensator (D-STATCOM). The parameters of the controller are also tuned to reduce the rating of D-STATCOM. Simulation results show that the proposed approach can reduce the sizes of compensating devices required which, in turn, reduces costs. The effectiveness of the proposed algorithm is verified through several case studies. 相似文献
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分布式光伏发电并网系统电压稳定性研究 总被引:1,自引:0,他引:1
鉴于分布式光伏发电并网系统的电压稳定性对现实生活有重要意义,从工程角度给出380/220V低压配电网电压失稳的实用判据,运用PSCAD软件构建了一个分布式光伏电源接入0.4kV配电网的3节点系统仿真模型,在此基础上分析了负荷增加、光照强度突降、环境温度增大以及负荷母线发生短路故障等扰动对负荷电压稳定性的影响。仿真结果表明,当负荷电压接近电压稳定限定值正常运行时,光照强度突降会使负荷母线电压失去稳定;温度变化对负荷电压的影响甚微;短路故障消除后负荷母线电压则能够快速得到恢复,不会导致电压失稳。 相似文献