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Search Results: 1 - 10 of 13566 matches for " 熊金鑫 "
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双馈型风电场并网短路电流特性研究
Research on Characteristics of Short-Circuit Current of DFIG Based Wind Farm
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乌睿, 小伏, 欧阳金鑫
Smart Grid (SG) , 2016, DOI: 10.12677/SG.2016.62009
Abstract:
以双馈型风力发电机为主的风电场在电力供应中占有越来越大的比重。双馈感应发电机输出的短路电流特性与同步发电机具有较大区别,目前双馈风电的故障暂态分析已成为风电并网的研究热点,但主要集中于单个机组并网系统方面。本文首先基于复频域分析了单台双馈风电机组的短路暂态过程,建立双馈型风电场暂态期间的工频、直流和转速频率分量的等效电路,对双馈型风电场的短路电流变化规律进行研究。推导出风电场中单台风电机组的短路电流增量表达式,基于短路电流的增量利用补偿增量的方法推导出双馈风电场的短路电流计算式。仿真验证了风电场内部的短路电流变化规律和解析表达式的准确性。
Wind farms consisting mainly of doubly-fed induction generators occupy more and more proportion in power supply. There do exist big differences of output short-circuit current characteristic between the doubly-fed induction generator and the synchronous generator. Research about the fault transient analysis of doubly-fed induction generators has become a hotspot; however, current research mainly focuses on the grid-connected system with single generator. This paper analyzes the short-circuit transient process of single doubly-fed induction generator in complex frequency domain and establishes the equivalent circuits of fundamental frequency, DC and rotor- speed frequency components in transient process respectively to study the changing regularity of short-circuit current of doubly-fed wind farms. Then this paper deduces the expression of short- circuit current increment of single generator in wind farm, and based on this, this paper further uses the improved weighted method to deduce the calculation formula of doubly-fed wind farm. Accuracy of the changing regularity of short-circuit current and the calculation formula is verified through simulation.
含电动汽车接入的配网动态功率不平衡解决方法
A Method Solving Dynamic Power Imbalance of Distribution Network Containing Electric Vehicles Access
 [PDF]

乌睿, 小伏, 胡婷立, 欧阳金鑫
Smart Grid (SG) , 2016, DOI: 10.12677/SG.2016.61004
Abstract:
随着电动汽车最近几年的快速发展,电动汽车接入配网产生的随机负载将增加配电变压器输送电能的波动性,加剧配网的功率不平衡。当大量电动汽车同时充电时可能超出传统配网的设计预期,配电变压器需要增加比平时更多的额外功率。若更换容量更大的配电变压器,可能仍难以满足要求,且增加不必要的投资。因此,本文提出一种仅需在现有配网结构上进行改进的动态功率平衡方法,采用三相电压型变流器通过直流线路联络配网中的各配电变压器以实现负载的合理分配和降低电动汽车负载的冲击。通过实测数据和蒙特卡洛模拟分析法建立电动汽车接入配网的负载模型,仿真分析表明该配网动态功率平衡系统具有较好的实用性。
With the rapid development of electric vehicles in recent years, the random load producing from the electric vehicles access to the distribution network may increase the volatility of electricity and aggravate the power imbalance of the distribution network. When a large number of electric vehicles are being charged at the same time, the random load may exceed the expectation design of the traditional distribution network and distribution transformers need to transfer more power. If using large capacity distribution transformers, it may still be difficult to meet the requirements and increase investment. Whereas, a method solving dynamic power imbalance of distribution network is proposed in this paper. In this solution, DC transmission lines are used to link different distribution transformers, and based on the Three-Phase Voltage Source Converter, which results in a reasonable distribution of the load and mitigates the impact of soaring load of electric vehicle. This paper describes a mathematical model of the load of distribution network containing electric vehicles access, which is simulated by measured data and Monte Carlo simulation method. The effectiveness of the proposed method is verified through the simulation analysis.
计及转子励磁控制的双馈感应发电机短路电流研究
欧阳金鑫, 小伏
中国电机工程学报 , 2014, DOI: 10.13334/j.0258-8013.pcsee.2014.34.009
Abstract: 双馈风电机组的规模化应用使电力系统的故障暂态特性发生变化。为了保障电力系统规划设计和保护控制的顺利实施,必须充分掌握双馈感应发电机(doublyfedinductiongenerator,DFIG)输出短路电流的特征。目前双馈感应发电机的暂态分析尚未计及变流器励磁控制的影响,使双馈风电机组短路电流还难以准确分析和计算。针对DFIG转子侧变流器励磁控制与发电机电磁过程的复杂暂态耦合,通过构建包含变流器调控过程及发电机电磁暂态的转子回路动态模型,重点分析了电网对称短路冲击作用下DFIG的暂态扰动及其传递特性,推导了计及励磁调节作用的DFIG定转子短路电流简化表达式,分析了励磁控制下DFIG短路电流的特征以及控制方式对暂态行为的影响,利用时域仿真验证了理论分析的正确性。
电网短路时双馈感应发电机转子电流的分析与计算
小伏,欧阳金鑫
中国电机工程学报 , 2012,
Abstract: 双馈风电机组对机端电压跌落比较敏感,随着风电装机容量的不断增加,电网故障时双馈风电机组转子电流的准确分析与评估变得十分重要,关系着双馈风电机组低电压穿越的实现以及故障电气量的分析与计算。从电网短路时双馈感应发电机的暂态过程出发,分析了双馈感应发电机定子动态过程以及变流器调控对转子电流的影响,采用空间矢量法和坐标变换方法推导了电网对称短路和不对称短路时转子电流的表达式,通过时域仿真和算例结果验证了表达式的正确性。所提出的表达式利用机端电压以及变流器控制参数即可计算得到电网短路时任意时刻的转子电流,具有清晰的物理意义以及较好的实用性。
接入配电网的双馈风力发电机短路电流特性及影响
欧阳金鑫,小伏
电力系统自动化 , 2010,
Abstract: 目前关于基于双馈感应发电机(DFIG)的风力发电机组短路电流的研究以非并网DFIG以及并网DFIG机端短路的情况为主,很少考虑电网对DFIG短路电流的影响。针对DFIG以分布式电源的方式接入配电网,其短路电流可能会受到配电网运行工况、短路点与DFIG接入点位置等影响的问题,结合DFIG的控制策略进行了理论推导和仿真分析。首先,基于感应电机的Park模型,对DFIG在电网故障时的短路过程进行了数学推导和分析,给出了计及控制策略变化的并网DFIG短路电流的解析表达式。然后,对DFIG短路电流的特性进行了分析,针对可能影响DFIG短路电流的各种因素进行了分析和仿真,并给出了相关结论。
基于改进层次模糊评判的智能变电站二次系统状态评估
Status Assessment of Secondary Equipment for Smart Substation Based on Improved Hierarchical Fuzzy Evaluation
 [PDF]

, 曾星星, 张友强, 何燕, 欧阳金鑫, 小伏, 曾勇
Smart Grid (SG) , 2015, DOI: 10.12677/SG.2015.52010
Abstract:
针对智能变电站各二次设备故障机理复杂、具有不确定性、难以有效评估的问题,提出了基于改进层次分析法和模糊评判理论的智能变电站二次系统综合评估方法。以运行检修规程、测试技术规范为基础,综合考虑运行经验、工作环境和检修记录,建立二次设备状态定量和定性评估指标体系,并根据各指标的相对重要性赋予相应权重;通过半梯形分布函数构建状态指标评分模型,并引入相对劣化度来表征二次设备状态转化程度的隶属函数,进而建立层次模糊评判矩阵;由此,建立基于改进层次模糊评判的智能变电站二次系统状态评估模型。实例分析表明该方法有效可行,为智能变电站二次系统健康状态评估提供了新的思路。
For smart substation secondary equipments’ failure mechanism are complex, uncertain and diffi-cult to be effectively evaluated, a comprehensive evaluation method based on improved analytic hierarchy process and fuzzy synthetic evaluation is proposed in this paper. On the basis of run maintenance procedures and test specification and taking operating experience, work environment and maintenance records into consideration, this paper establishes the quantitative and qualitative state evaluation index system of secondary equipment and gives the corresponding weight according to the relative importance of each indicator. Through building the scoring model of state indicator by the semi-trapezoidal distribution function and introducing the relative deterioration degree to characterize the membership function of secondary equipment status transformation degree and to establish a hierarchical fuzzy evaluation matrix. Thus, a condition assessment model of smart substation secondary system based on improved analytic hierarchy process and fuzzy synthetic evaluation is established. Example analysis shows that this method is effective and feasible and provides a new way for the health assessment of smart substation secondary system.
双馈风力发电机Crowbar电阻优化设计研究
The Research on Optimization Design of DFIG Crowbar
 [PDF]

陈军, 肖超, 欧阳金鑫, 小伏, 余锐, 陈愚
Smart Grid (SG) , 2015, DOI: 10.12677/SG.2015.54025
Abstract:
应用Crowbar保护电路是实现双馈风力发电机组低电压穿越广泛应用的手段,而Crowbar电阻的选取对穿越过程有着决定性的作用。目前,针对Crowbar电阻的设计虽已有很多研究,但大都是得到Crowbar电阻的大概选择范围,然后在这范围内用试凑法进行Crowbar电阻选取,从而难以到达最优设计效果且效率不高。本文提出一种基于模糊隶属函数的Crowbar电阻设计方法来提高Crowbar电路的设计效率并获得更高满意度的低电压穿越过程,首先分析电网发生三相短路时双馈风力发电机的故障特性,然后分析了Crowbar保护电路中阻值选取的约束条件,采用隶属度函数方法建立了Crowbar阻值选取目标函数,在Matlab仿真软件平台上对所选方法进行了仿真验证,仿真结果证明了基于模糊隶属函数的Crowbar电阻设计方法可以提高设计效率并获得更好的低电压穿越过程。
A widely used way to realize LVRT is adding a crowbar circuit to the DFIG, however, the choice of crowbar resistance is difficult and it has a key influence on LVRT during the grid faults. In recent years, there have been many studies on the choice of crowbar resistance, however, these studies generally give a broad resistance choice scope, and the designer can only choose the crowbar re-sistance by trial and error method to get a better LVRT process, hence, the efficiency is not high. In this paper, a crowbar resistance design method based on fuzzy membership function is proposed, it can improve the design efficiency of crowbar circuit greatly and achieve a higher degree of sa-tisfaction during LVRT process. This paper analyzes the change process of stator and rotor fault current, obtains the constraints relation of crowbar resistance with rotor side current and DC-link voltage, then transforms the crowbar resistance constraint equations into the fuzzy membership function, and finally establishes a DFIG model with Crowbar circuit on the Matlab simulation soft-ware platform. The simulation results which verify this crowbar resistance design method can get the satisfy result on the maximum balance and improve the efficiency of selection of the crowbar resistance greatly.
电网短路时并网双馈风电机组的特性研究
欧阳金鑫,小伏,张涵轶
中国电机工程学报 , 2011,
Abstract: 双馈感应风力发电机组(doublyfedinductiongenerator,DFIG)对电网扰动十分灵敏,在电网发生故障期间双馈风电机组与电网的相互影响会造成电网暂态特性以及短路电流分布的显著变化。但是由于双馈感应发电机组与同步发电机组的结构及运行原理均不相同,且目前对其故障过程的研究也比较有限,使得并网双馈风电机组的故障特性还不甚清晰。在以双馈风电机组为主的风电大规模并网背景下,电网的安全稳定运行面临着严峻的挑战。从双馈风电机组的控制策略对其故障特性的影响机制出发,对双馈风电机组在电网发生对称以及不对称短路情况下的短路过程进行深入分析,并进一步推导了适用于不同电网短路情况的并网双馈风电机组短路电流表达式,仿真和算例结果验证了该表达式的正确性。
电网故障时双馈风电机组定子电压特性及影响分析
小伏,欧阳金鑫,文安
电力系统自动化 , 2012,
Abstract: 随着以双馈风力发电机为主的风力发电的大规模并网,电网故障期间并网双馈风电机组对电网的影响不断显现,使电网安全稳定运行面临着严峻挑战。为了有效评估双馈风电机组的暂态过程及其对电网的影响,需要掌握电网故障期间双馈发电机机端电压的大小及变化规律。基于双馈发电机的暂态过程,推导了稳态运行以及外部电网三相短路下双馈发电机定子电压的表达式。在此基础上,对双馈发电机定子电压的暂态特性进行了研究,明确了定子电压的影响因素,分析了电网故障时双馈风电机组对电网暂态电压分布的影响。最后通过仿真进一步分析了定子电压的变化规律并验证了推导的正确性。
我国首例细胞核移植家兔诞生
金鑫
扬州大学学报(农业与生命科学版) , 1991,
Abstract: ????
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