共查询到20条相似文献，搜索用时 156 毫秒
1.
为了改善直流输电系统在各种运行条件下的鲁棒性,提出一种反馈线性化控制器。通过建立反馈线性化控制器的数学模型,将非线性系统的控制律表示为误差的函数,并且采用神经网络的算法得到控制器的系数,对交流母线发生短路故障和受端系统的短路比发生改变的情况进行了仿真。仿真结果表明,反馈线性化控制器在稳定直流电流方面比常规的PI控制器具有更好的性能。 相似文献
2.
3.
依据柔性直流输电技术的独有特点,针对同一网络中连接无源和有源网络的稳定性分析,首先建立换流站数学模型,将abc三相坐标系的模型转化为dq0坐标系,推导出换流站的等效数学表达式,并对其运行原理和工作特性进行理论分析;其次建立dq0坐标系下的电流控制环,通过设计PI控制器控制交流系统和电压源换流器之间的有功功率及无功功率。利用Matlab软件成功对这个三端系统进行模拟,对其性能进行分析,体现三端直流输电系统的灵活性、可控性、智能性等优点。 相似文献
4.
黄静 《荆门职业技术学院学报》2009,24(7):19-24
作为高压直流输电系统的控制核心,换流站控制系统的设计决定着整个直流输电系统的性能。本文结合实际工程,以直流背靠背挟流站为对象,在分析直流控制策略的基础上探讨了其主要子控制系统-极控系统的设计方案,实现了对换流阀触发角和换流变压器抽头的协调控制。同时,为了满足系统过负荷状态下的安全运行,提出了以系统过负荷时间表征过负荷能力的过负荷监控思路。 相似文献
5.
相对于普通的交流输电系统,高压直流输电系统优势在于电力的远距离传输、成本更低以及电力损失更小.安徽省是西南水电外送特高压走廊的途径省份之一,但目前还没有针对直流输电线直的研究,所以高压直流输电线路对环境影响的监测与研究需求日益迫切.本文采用实地监测与数据分析相结合的方式,分析了高压直流输电线路周边电磁辐射环境,同时从环保角度提出在沿线周边进行建筑规划时的建议. 相似文献
6.
7.
刘作鹏 《湖北成人教育学院学报》2012,18(6):158-160
近年来,随着我国经济高速发展,我国的电力需求也在不断增长。由于高压直流输电具有送电距离远、送电容量大、架线成本低、控制灵活等特点,现已成为我国输电工程中重要的输电方式,在未来的西电东送、南北互供的全国联网中,将发挥重要作用。本文对我国电网现状及趋势、高压直流输电技术的兴起、高压直流输电技术、高压直流输电针对交流输电的优点和特点、直流输电应用所受的限制因素、直流输电技术适应我国电网发展的规划与需要等六大方面做了论述与探讨。对高压直流输电的研究与应用将是我国现阶段电网发展的需要。 相似文献
8.
高压直流输电技术的特点及其在我国的发展前景 总被引：1，自引：0，他引：1
程江 《江西电力职业技术学院学报》2005,18(2):24-25
高压直流输电技术自1954年问世以来,由于对高电压、大距离、不同步运行的两个交流电网的连接、改善交流电网的稳定性等方面具有独到的优点,近50年来已取得很大的发展。高压直流输电技术在我国具有广阔的发展前景。 相似文献
9.
王海茗 《常熟理工学院学报》2019,33(2)
采用基于高压直流输电逆变侧模块化多电平换流器(Modual Multilevel Conveter,MMC)的虚拟同步发电机控制方法,使得直流输电系统逆变侧变换器能够模拟同步发电机运行,为交流电网提供惯性和阻尼.建立了虚拟同步发电机的电气及机械模型,仿真实现了虚拟同步发电机控制在MMC上的控制方法.仿真结果表明,直流输电系统逆变侧MMC采用虚拟同步发电机(Virtual Synchronous Generator,VSG)控制技术,能够提供一定的惯性和阻尼,较好地实现对交流系统的有功-频率控制和无功-电压控制. 相似文献
10.
云广特高压直流输电系统是中国第一条±800kV电压等级的直流输电工程.由于传输功率高,其稳定性关系到整个电网的安全运行.直流电流测量装置(CT)是直流输电控制保护系统信号采集的重要模块,以2012年9月12日云广特高压直流输电系统一起单极闭锁事件为例,分析了CT装置对整个特高压直流输电系统运行稳定性的影响,对比考察了历次换相失败的历史电流数据,并对电流谐波状况进行分析,定位发生故障的为极1母线CT二次测量回路. 相似文献
11.
The modern travelling wave based fault location principles for transmission lines are ana-lyzed. In order to apply the travelling wave principles to HVDC transmission lines, the special tech-nical problems are studied. Based on this, a fault locating system for HVDC transmission lines is developed. The system can support modern double ended and single ended travelling wave princi-ples simultaneously, and it is composed of three different parts: travelling wave data acquisition and processing system, communication network and PC based master station. In the system, the fault generated transients are induced from the ground leads of the over-voltage suppression ca-pacitors of an HVDC line through specially developed travelling wave couplers.The system was applied to 500 Kv Gezhouba-Nanqiao(Shanghai)HVDC transmission line in China. Some field op- eration experiences are summarized, showing that the system has very high reliability and accu- racy,and the maximum location error is about 3 km(not more than 0.3% of the total line length). Obviously, the application of the system is successful, and the fault location problem has finally been solved completely since the line operation. 相似文献
12.
This paper presented a control design methodology for a proton exchange membrane fuel cell （PEMFC） generation system for residential applications. The dynamic behavior of the generation system is complex in such applications. A compre- hensive control design is very important for achieving a steady system operation and efficiency. The control strategy for a 60 kW generation system was proposed and tested based on the system dynamic model. A two-variable single neuron proportional-integral （PI） decoupling controller was developed for anode pressure and humidity by adjusting the hydrogen flow and water injection. A similar controller was developed for cathode pressure and humidity by adjusting the exhaust flow and water injection. The desired oxygen excess ratio was kept by a feedback controller based on the load current. An optimal seeking con- troller was used to trace the unique optimal power point. Two negative feedback controllers were used to provide AC power and a suitable voltage for residential loads by a power conditioning unit. Control simulation tests showed that 60 kW PEMFC generation system responded well for computer-simulated step changes in the load power demand. This control methodology for a 60 kW PEMFC generation system would be a competitive solution for system level designs such as parameter design, performance analysis, and online optimization. 相似文献
13.
ZHANG Peng YE Cheng-qing MA Xue-ying CHEN Yan-hua LI Xin 《浙江大学学报(A卷英文版)》2007,8(1):113-118
INTRODUCTION Internet congestion occurs when the aggregated demand for a resource (e.g., link bandwidth exceeds the available capacity of the resource). Resulting effects from such congestion include long delays in data delivery, waste of resources due to lost or dropped packets, and even possible congestion col-lapse (Athuraliya et al., 2001). Therefore it is very necessary to avoid or control network congestion. The active queue management (AQM) scheme imple-mented in routers is desig… 相似文献
14.
陈平 《福建工程学院学报》2005,3(6):625-627
针对模糊控制器的缺点，提出一种基于PI算法的自调整比例因子模糊控制器。在简单模糊控制器的基础上，利用PI控制算法自动调整模糊控制器比例因子。通过对工业锅炉汽包水位控制系统的应用仿真，表明这种自调整比例因子模糊控制器可提高模糊控制系统的性能，同时对汽包水位的虚假水位现象有较好抑制。 相似文献
15.
电厂实时信息系统（Plant Infomaation System）是基于客户／服务器（C／S）结构的电厂实时信息采集、存储和管理的系统,在电厂控制系统和管理信息系统之间起着“桥梁”作用,是实现电厂管控一体化的有力保证。在PI系统结构、功能及功能模块的基础上,建立一套完整的供电煤耗率实时计算公式并,提出基于PI系统的节能降耗问题研究思考。 相似文献
16.
为了满足工程上广泛应用的PI控制器的性能要求，又能克服一般PI控制器参数整定和调整的困难，基于dqo同步旋转坐标系下的UPFC串联侧的数学模型。采用BP神经网络PI控制器分别对有功和无功进行控制，使PI控制器的参数可以自动整定，省去了繁琐的人工整定过程，并能随系统的变化在线调节，使有功和无功达到较好的控制性能。 相似文献
17.
18.
风速的随机性、间歇性及不确定性,必将导致风电场的输出功率也具有随机波动性和间歇性,风电系统的输出功率影响电网的安全稳定运行和电能质量．通过构建了以鼠笼式感应电机为发电系统的定速变桨距风力发电系统,展开功率跟踪控制系统分析．给出了风力机空气动力学特性和建模方法,建立了传动链数学模型和感应发电机的数学模型．设计了转矩控制环、速度控制环,给出了实现功率跟踪的功率控制环设计思路,仿真结果表明,该系统能实现风电系统的最优功率跟踪控制． 相似文献
19.
20.
Collapses of transmission towers were often observed in previous large earthquakes such as the Chi-Chi earthquake in Taiwan
and Wenchuan earthquake in Sichuan, China. These collapses were partially caused by the pulling forces from the transmission
lines generated from out-of-phase responses of the adjacent towers owing to spatially varying earthquake ground motions. In
this paper, a 3D finite element model of the transmission tower-line system is established considering the geometric nonlinearity
of transmission lines. The nonlinear responses of the structural system at a canyon site are analyzed subjected to spatially
varying ground motions. The spatial variations of ground motion associated with the wave passage, coherency loss, and local
site effects are given. The spatially varying ground motions are simulated stochastically based on an empirical coherency
loss function and a filtered Tajimi-Kanai power spectral density function. The site effect is considered by a transfer function
derived from 1D wave propagation theory. Compared with structural responses calculated using the uniform ground motion and
delayed excitations, numerical results indicate that seismic responses of transmission towers and power lines are amplified
when considering spatially varying ground motions including site effects. Each factor of ground motion spatial variations
has a significant effect on the seismic response of the structure, especially for the local site effect. Therefore, neglecting
the earthquake ground motion spatial variations may lead to a substantial underestimation of the response of transmission
tower-line system during strong earthquakes. Each effect of ground motion spatial variations should be incorporated in seismic
analysis of the structural system. 相似文献