检索结果-南通市图书馆

Dynamic Frequency Support and DC Voltage Regulation Approach for VSC-MTDC Systems

在线全文

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2023年第2期9卷 645-658页

作者： chongru liu Haoyu liu Siwen Jiang Le Zheng State Key Laboratory for Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing 102206China

When an additional frequency control is implemented in the voltage source converter-based multi-terminal high voltage direct current(VSC-MTDC)system,the DC grid is capable of responding to a frequency disturbance in the AC ***,the original additional frequency control may cause the DC voltage to exceed the limit when providing power for a severe frequency disturbance,threatening the security of the DC system.A novel dynamic additional frequency control strategy for the VSC-MTDC system is developed based on the relationship between the DC voltage and the frequency droop coefficient.A dynamic frequency droop coefficient is designed to adaptively adjust the support power of the DC grid,balancing the frequency regulation of the disturbed AC system and the voltage stability of the DC grid.A DC voltage recovery method based on multi-converter cooperation is proposed to cope with the DC voltage deviation caused by the additional frequency *** validate the advantages and satisfactory performance of the proposed method during power disturbances with different severities and for the process of DC voltage recovery.

关键词： Additional frequency control DC voltage recovery module dynamic frequency droop coefficient VSCMTDC

Mechanism Analysis of Additional Damping Control Strategies for the High-frequency Resonance of MMC Connected to AC Grid

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2023年第3期9卷 1173-1181页

作者： Yanqi Hou chongru liu Yu Wang Wei Kong State Key Laboratory for Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing 102206China State Grid Economic and Technological Research Institute Co.Ltd. Beijing 102209China State Grid Corporation of China Beijing 100031China

High-frequency resonance can occur when a modular multilevel converter(MMC)is inserted into an AC *** damping control is a relatively low-cost resonance suppression strategy compared to passive damping *** paper analyzes the influences of a feed-forward voltage filter and feedback current filter for the inner controller for the high-frequency impedance characteristics of the MMC based on a ***,the mechanism,influencing factors,and limitations of the existing strategy including an additional lowpass filter in the voltage feed-forward stage are ***,a resonance suppression strategy for the inclusion of additional cascaded notch filters in the voltage feed-forward stage is proposed,and its parameter design method and applicable scenarios are *** addition,this paper analyzes the effects of the inclusion of an additional control in other stages for the inner controller of the ***,the correctness of the theoretical analysis and the proposed strategy is verified based on the simulation of an actual project on PSCAD/EMTDC.

关键词： Additional damping control strategy additional cascaded notch filters additional low-pass filter modular multilevel converter(MMC) high-frequency resonance

Analysis on Local and Concurrent Commutation Failure of Multi-infeed HVDC Considering Inter-converter Interaction

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2022年第4期10卷 1050-1059页

作者： Bilawal Rehman chongru liu Huan Li Chuang Fu Wei Wei State Key Laboratory for Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijing 102206China Department of Electrical Engineering Technology National Skills University IslamabadIslamabad45710Pakistan State Key Laboratory of HVDC Electric Power Research InstituteChina Southern Power GridGuangzhou 510663China

This paper provides a comprehensive analysis of local and concurrent commutation failure(CF)of multi-infeed high-voltage direct current(HVDC)system considering multi-infeed interaction factor(MIIF).The literature indicates that the local CF is not influenced by MIIF,whereas this paper concludes that both the local CF and concurrent CF are influenced by *** ability of remote converter to work under reduced reactive power enables its feature to support local converter via inter-connection *** MIIF measures the strength of electrical connectivity between *** MIIF gives a clearer path to remote converter to support local converter,but at the same time,it provides an easy path to local converter to disturb remote converter under local *** presence of nearby converter increases the local commutation failure immunity index(CFII)while reducing concurrent *** MIIF causes reactive power support to flow from remote converter to local converter,which reduces the chances of CF.A mathematical approximation to calculate the increase in local CFII for multi-infeed HVDC configurations is also proposed.A power flow approach is used to model the relation between MIIF and reactive power support from remote *** local and concurrent CFIIs are found to be inverse to each other over MIIF;therefore,it is recommended that there is an optimal value of MIIF for all converters in close electric proximity to maintain CFII at a certain *** numerical results of established model are compared with PSCAD/EMTDC *** simulation results show the details of the influence of MIIF on local CF and concurrent CF of multi-infeed HVDC,which validates the analysis presented.

关键词： Commutation failure(CF) multi-infeed highvoltage direct current(HVDC)system multi-infeed interaction factor commutation failure immunity index(CFII)

Data-driven Estimation for a Region of Attraction for Transient Stability Using the Koopman Operator

在线全文

学校读者我要写书评

暂无评论

CSEE Journal of Power and Energy Systems 2023年第4期9卷 1405-1413页

作者： Le Zheng Xin liu Yanhui Xu Wei Hu chongru liu the School of Electrical and Electronic Engineering North China Electric Power UniversityBeijing 102206China Department of Electrical Engineering Tsinghua UniversityBeijing 100084China

This paper presents a novel Koopman Operator based framework to estimate the region of attraction for power system transient stability *** Koopman eigenfunctions are used to numerically construct a Lyapunov *** the level set of the function is utilized to estimate the boundary of the region of *** method provides a systematic method to construct the Lyapunov function with data sampled from the state space,which suits any power system models and is easy to use compared to traditional Lyapunov direct *** addition,the constructed Lyapunov function can capture the geometric properties of the region of attraction,thus providing useful information about the instability *** method has been verified by a simple illustrative example and three power system models,including a voltage source converter interfaced system to analyze the large signal synchronizing instability induced by the phase lock loop *** proposed method provides an alternative approach to understanding the geometric properties and estimating the boundary of the region of attraction of power systems in a data driven *** Terms-Koopman operator,lyapunov function,power system transient stability,region of attraction.

关键词： Koopman operator lyapunov function power system transient stability region of attraction.

Steady‐state power operation region of a modular multilevel converter connecting to an AC grid

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

High Voltage 2021年第6期6卷 1009-1023页

作者： Jiecong Wang chongru liu Udaya DAnnakkage Xiao Li Chenbo Su State Key Lab.for Alternate Electrical Power System with Renewable Energy Sources North China Electric Power UniversityBeijingChina University of Manitoba WinnipegCanada

The modular multilevel converter(MMC)has become a widely used topology for voltage source converter-based high‐voltage direct current transmission *** calculate the power operation region of an MMC directly and efficiently,we propose a novel steady‐state phasor model of the *** model is expressed as an equivalent capacitance in series with a voltage source,where parameters are independent of alternating current(AC)electrical *** on the model,we propose an open‐loop approach to determine the operation region boundary of MMC by calculating the envelopes of the P-Q *** effect of MMC parameters,the circulating current control,and the short‐circuit ratio of the AC grid to the power operation region can be determined by the size and position of the power operation *** proposed approach and analysis results were verified by an MMC/AC simulation model built in PSCAD/EMTDC.

关键词： PSCAD/EMTDC operation power

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

交直流混合输电系统灵敏度分析

电力系统自动化 2007年第12期31卷 45-49页

作者：刘崇茹张伯明华北电力大学电力系统保护与动态安全监控教育部重点实验室北京市102206 清华大学电机系电力系统国家重点实验室北京市100084

研究了稳态条件下交直流(AC/DC)混合输电系统中交流(AC)子系统与直流(DC)子系统之间的相互作用和相互影响。采用灵敏度分析方法,分析和讨论了DC系统控制参数对AC/DC混合系统运行特性的影响,以及在DC系统存在的条件下,AC系统控制量对AC... 详细信息

研究了稳态条件下交直流(AC/DC)混合输电系统中交流(AC)子系统与直流(DC)子系统之间的相互作用和相互影响。采用灵敏度分析方法,分析和讨论了DC系统控制参数对AC/DC混合系统运行特性的影响,以及在DC系统存在的条件下,AC系统控制量对AC系统其他变量的影响。系统地分析和计算了AC/DC系统的各类灵敏度矩阵,这对潮流控制、参数调整和电压估算等问题都有实际的意义。

关键词：交直流输电灵敏度分析潮流控制参数调整

考虑换流变压器和无功补偿协调控制计算AC/DC系统有功-电压曲线

在线全文

学校读者我要写书评

暂无评论

电力自动化设备 2009年第1期29卷 50-53页

作者：刘崇茹张伯明华北电力大学电力系统保护与动态安全监控教育部重点实验室北京102206 清华大学电机工程与应用电子技术系北京100084

在绘制交直流混合输电系统有功-电压曲线的过程中应该考虑直流的调整控制作用。如果将直流系统简单视为定功率负荷,通过仿真发现,计算得到的静态电压稳定裕度偏保守,并不能反映直流系统的控制作用。在采用连续潮流法求解交直流混合系统... 详细信息

在绘制交直流混合输电系统有功-电压曲线的过程中应该考虑直流的调整控制作用。如果将直流系统简单视为定功率负荷,通过仿真发现,计算得到的静态电压稳定裕度偏保守,并不能反映直流系统的控制作用。在采用连续潮流法求解交直流混合系统有功-电压曲线的过程中,根据换流器的阀组控制方式和直流系统运行特征(无功功率控制方式),调整换流变压器分接头,并根据无功控制需求投入换流站无功补偿装置,求得的有功-电压曲线及电压稳定临界点能够反映直流输电系统控制对电力系统稳定性的影响。

关键词：电力系统交直流系统换流变压器无功补偿有功-电压曲线

基于PSCAD的大规模钳位双子模块-模块化多电平换流器高效仿真建模方法

在线全文

学校读者我要写书评

暂无评论

电工技术学报 2015年第S2期30卷 113-119页

作者：刘崇茹洪国巍新能源电力系统国家重点实验室(华北电力大学) 北京102206

采用钳位双子模块(CDSM)的模块化多电平换流器(MMC)具有较高开关器件利用率和直流故障穿越能力。针对大规模CDSM模块化多电平换流器(CDSM-MMC)仿真效率低的问题,分析了CDSM在闭锁状态和非闭锁状态下的不同动态特性,基于Dommel等值计算... 详细信息

采用钳位双子模块(CDSM)的模块化多电平换流器(MMC)具有较高开关器件利用率和直流故障穿越能力。针对大规模CDSM模块化多电平换流器(CDSM-MMC)仿真效率低的问题,分析了CDSM在闭锁状态和非闭锁状态下的不同动态特性,基于Dommel等值计算原理建立了一种戴维南等效模型。为了提高闭锁状态下的仿真精度,引入EMTDC中开关器件的函数接口,并设计了闭锁状态与正常状态切换的等效电路。同时,通过进一步简化,推导建立了开关信号模型。在PSCAD/EMTDC中搭建了CDSM模型和提出的两种模型,证明了所提出模型的仿真准确度和仿真效率。

关键词：模块化多电平换流器钳位双子模块电磁暂态仿真戴维南定理 Dommel等值

在线全文

学校读者我要写书评

暂无评论

基于虚拟阻抗补偿的PMSG恒导纳建模方法

中国电机工程学报 2024年第6期44卷 2362-2373,I0024页

作者：史一博刘崇茹新能源电力系统国家重点实验室(华北电力大学) 北京市昌平区102206

永磁直驱风力发电系统结构复杂、节点数多,在进行电磁暂态实时仿真时,若采用传统建模方法会因系统导纳矩阵计算过于复杂导致仿真规模严重受限。该文提出一种基于虚拟阻抗补偿的永磁同步发电机(permanent magnet synchronous generator,P... 详细信息

永磁直驱风力发电系统结构复杂、节点数多,在进行电磁暂态实时仿真时,若采用传统建模方法会因系统导纳矩阵计算过于复杂导致仿真规模严重受限。该文提出一种基于虚拟阻抗补偿的永磁同步发电机(permanent magnet synchronous generator,PMSG)恒导纳建模方法,该方法基于传统发电机模型,通过在转子上补偿虚拟阻抗的方式使发电机导纳矩阵固定,并以暂态误差最小为目标,对阻抗参数进行优化设计;再通过结合换流器的伴随离散电路模型,可建立PMSG完整恒导纳模型并进行电磁暂态仿真,能够节省大量的计算资源。仿真试验证明,该模型具有较高的仿真精度,并且可以用于FPGA等离散化硬件仿真平台上,具有良好的适用性。

关键词：恒导纳模型虚拟阻抗补偿永磁同步电机