分布式光伏发电并网数字化建模与仿真北大核心

为了改善光伏发电性能,需要对分布式光伏发电并网控制技术进行研究。提出基于MPPT控制的分布式光伏发电并网建模方法,建立光伏电池模型,在所建模型的基础上研究光伏发电系统输出功率受光照强度变化的影响。并利用MPPT控制方法跟踪分布式光伏系统的最大功率点,提高分布式光伏系统在运行过程中的输出功率。通过滑膜控制对光伏并网逆变器进行控制,保持电网电压与光伏发电系统输出电流的同步性,实现分布式光伏系统并网发电。通过仿真,验证了所提方法可有效地实现光伏阵列最大输出功率的跟踪,满足分布式光伏发电并网系统的运行要求。     

分布式电源入网对聊城电网安全运行的影响

本文主要是结合聊城市分布式电源接入电网项目的情况,归纳总结了至今以来分布式电源的发展规律和态势,从继电保护、短路电流、无功平衡、经济运行等几个方面分析了光伏发电并网对电网的影响,并阐述了分布式电源并网运行后对电网管理制度的冲击,公司作为重要的分布式电源并网利用参与者,应该着重思考与各方合作共赢的机制,以合作共赢的机制来确保分布式电源并网利用的安全性和可持续性。     

分布式电源并网潮流计算

分布式发电系统并网对地区电网的潮流计算提出新的挑战和要求。基于分布式发电系统并网结构和控制特性,建立微型燃气轮机、光伏、风力发电、燃料电池几种典型的分布式发电系统并网系统在潮流计算中数学模型。针对前推回代法支路编号复杂,无法适应运行方式变化等不足,从实现方法上提出了一种基于"叶节点"的前推回代法。算例表明,该方法能很好地解决分布式发电系统并网潮流计算,具有较强通用性和实用性。     

遗传算法优化粒子群的分布式光伏并网控制方法研究

为了促进分布式光伏发电技术的发展、提高分布式光伏并网的发电效率和质量,提出遗传算法优化粒子群的分布式光伏并网控制方法。通过建立光伏阵列模型、可中断负荷模型和储能系统模型,完成了分布式光伏发电并网系统的能源建模。以降低节点电压偏离额定值、稳态运行有功损耗和使分布式光伏发电并网系统功率最大化为目标,构建了分布式光伏并网调控模型。采用遗传算法优化粒子群对调控模型进行求解,实现分布式光伏并网的有效控制。试验结果表明,该控制方法具有较高的控制精度和较快的响应速度,确保了配电网运行的稳定性,能够有效降低电流谐波总畸变率。该研究促进了分布式光伏发电技术的发展,为分布式光伏并网控制提供了参考。     

基于差分进化算法的分布式电源DG规划设计

分布式电源(DG)是一种可以与环境兼容,利用清洁能源发电,可以满足用户对电量的特殊需求的发电装置。因此,将分布式电源接入电网,不仅可以保证电网的运行安全,提高供电可靠性,还可以将多余的电力反馈给电网。分布式发电接入配电网后,不一定能降低配电系统的网损,提高电网的稳定性,还有可能会因为并网的规划方案设计的不够好反而对电网造成不利影响,因此,分布式电源接入配电网的规划尤为重要。在分布式发电的并网规划中,最重要的是选择分布式发电的接入位置和容量。因此,本文选择具有结构简单、执行方便、优化效率高、参数设置简单、鲁棒性好等优点的差分算法,通过建立系统,并用Matlab进行了仿真,选择其最佳位置,计算出最优容量,并得到最优目标函数,来达到最佳的规划设计。     

浅谈分布式光伏发电

分布式光伏发电作为新型能源,在未来发展具有很广阔的前景。文章结合目前分布式光伏发电实际发展情况,介绍了光伏发电原理、光伏电源对配电网的影响及系统保护配置等,并具体介绍了分布式发电并网调度管理的运行步骤。     

浅谈分布式光伏发电

分布式光伏发电作为新型能源,在未来发展具有很广阔的前景。文章结合目前分布式光伏发电实际发展情况,介绍了光伏发电原理、光伏电源对配电网的影响及系统保护配置等,并具体介绍了分布式发电并网调度管理的运行步骤。     

分布式光伏大规模并网的影响分析及对策

随着国家一系列光伏发电扶持政策的发布,社会各界对光伏发电的项目关注度也越来越高。光伏发电作为清洁能源,将是未来的发展趋势,越来越多的光伏发电项目将并网运行。本文重点对分布式光伏项目大规模并网对电网的影响进行了初步探讨。     

分布式光伏发电对电能采集及线损的影响分析

掌握分布式光伏发电对电网存在的影响,是做好分布式光伏发电并网规划,促进其有效推广应用的前提与基础。本文从分布式光伏发电基本概念出发,在了解分布式光伏发电特征,掌握分布式光伏发电并网情况后,探寻了分布式光伏发电对电能采集与线路损耗存在的影响,希望为分布式光伏发电有效运用提供借鉴。     

新型电力系统下大规模电源接入配电网的线损变化趋势分析

目前,分布式光伏在贵州爆发式增长,分布式光伏发电具有随机性、波动性、地域性等特点,接入配电网中会造成功率波动等影响,进而影响配电网的电能损耗。但是现有的电网线损计算分析并未考虑大规模新能源接入对线损的影响,如果沿用现有方法计算、开展接入工作则会造成较大的误差。首先,本文介绍了近年来贵州电网分布式光伏发展、并网情况;其次,介绍目前分布式光伏发电并网方案;之后,从分布式光伏发电特征、台区用电特征等方面进行介绍,并对光伏接入对台区线损影响进行理论计算与仿真分析;此后,以光伏接入电网的实际台区为例,通过历史数据和现场应用情况,从接入位置、接入容量等进行验证。最后,对分布式光伏接入配电网对分线分台区线损的影响进行分析总结。     

A parallel distributed knowledge-based system for turbine generator fault diagnosis

Real-time fault diagnosis for turbine generators is a fairly complex problem. Parallel processing and distributed artificial intelligence (DAI), as rapidly emerging and promising technologies, provide powerful tools for solving this difficult problem. Based on the study of the basic fault diagnosis process for turbine generators, the idea of parallel processing and DAI is introduced into the field of fault diagnosis. Parallelism at four different levels in the fault diagnosis process is proposed. It lays down the theoretical basis for the development of a real-time parallel distributed fault diagnosing system for the turbine generator of a 300 MW fossil power plant. The diagnostic system can continuously monitor the vibration of the turbine generator as well as various process data.     

基于连续体模型的电力系统频率动态研究

针对电力系统连续体建模过程中发电机参数分配存在的复杂性较大的问题,提出了一种基于最短路径的连续体模型参数分配方法。该方法首先通过摇摆方程将传统离散系统连续化,并根据本文设计的算法计算得到存在扰动的发电机到剩余发电机的所有路径,选取扰动传播的最短路径,并将发电机惯性常数平均分配到各最短路径。每条最短路径上再采用高斯分配法将分配得到的参数进行再次分配,给出了参数分配过程中的准确表达式。通过对New England 10机39节点标准数据集进行算例仿真可知,从扰动源出发到各发电机的传播路径数量庞大,参数分配复杂度很大。通过选取各对应的9条最短路径进行参数分配,大大降低了参数分配的计算复杂度,同时使得对整个系统的分析和描述更加准确。     

Small-signal stability and decentralized control design for electric energy systems with a large penetration of distributed generators

This paper investigates small-signal stability and decentralized control design for distribution electric energy systems with a large penetration of distributed generators. Two real world distribution systems are studied in this paper. The first system is the IEEE 30-node distribution system and the second one is the distribution system on Flores Island, one of the western group islands of the Azores Archipelago.The Block Gerschgorin Theorem and Liapunov function-based stability criteria are applied to formally state sufficient conditions for small-signal stability. The results illustrate that when the governor control of distributed generators is designed without considering interactions between generators, small-signal instability could occur in the system and even the sufficient conditions for stability would not be satisfied.In the next step, the paper assesses control design to stabilize potentially unstable distribution systems. The main focus is on designing enhanced decentralized control based on the introduced stability criteria. The findings illustrate that implementing the enhanced decentralized control could ensure stability and support a large penetration of distributed generators.     

Simulation of isolated operation in fault condition by loop power flow controller

6.6 kV overhead distribution systems are currently constructed in Japan as radial networks. The load imbalance of each feeder therefore has a negative impact on voltage stability. On the other hand, disconnecting distributed generators with faults causes line overload or under-voltage. Therefore, controlling line voltage and line power flow on the distribution system is critical for the open access of indefinite numbers of distributed generators. We are investigating a new loop or mesh structure distribution system to maximise network capacity. This paper describes a control method for a loop power flow controller (LPC) focusing on 1 line-to-ground (LG) fault states.     

Hybrid neuro-swarm optimization approach for design of distributed generation power systems

The global energy sector faces major challenges in providing sufficient energy to the worlds ever-increasing energy demand. Options to produce greener, cost effective, and reliable source of alternative energy need to be explored and exploited. One of the major advances in the development of this sort of power source was done by integrating (or hybridizing) multiple different alternative energy sources (e.g., wind turbine generators, photovoltaic cell panels, and fuel-fired generators, equipped with storage batteries) to form a distributed generation (DG) power system. However, even with DG power systems, cost effectiveness, reliability, and pollutant emissions are still major issues that need to be resolved. The model development and optimization of the DG power system were carried out successfully in the previous work using particle swarm optimization (PSO). The goal was to minimize cost, maximize reliability, and minimize emissions (multi-objective function) subject to the requirements of the power balance and design constraints. In this work, the optimization was performed further using Hopfield neural networks (HNN), PSO, and HNN-PSO techniques. Comparative studies and analysis were then carried out on the optimized results.     

分布式电源接入场景下的电网振荡攻击建模与检测

随着分布式电源在电网中所占比重的不断提升,针对分布式电源的攻击将给电网带来更严重的安全威胁。攻击者可以通过网络入侵手段协同控制电网中防御较弱的配网侧分布式电源功率输出,最终影响发电侧发电机等关键设备的安全运行。为保障电网安全稳定运行,亟需研究针对分布式电源接入场景下的安全威胁及其防御措施。首先,本文在电力系统动态模型基础之上建立了电网振荡攻击的最小代价攻击模型,通过协同控制多个分布式电源的功率,在牺牲最少被控节点的前提下导致电网发生振荡。其次,针对现有振荡检测算法的不足,本文提出一种启发式的攻击源检测算法,通过分析系统内各节点的势能变化,可有效辅助定位攻击源。算例仿真分析结果验证了通过最小代价攻击影响电网稳定运行的可行性,以及攻击检测方法的有效性。     

基于OPC和Winsock API的远程数据采集系统设计

在现代化区域发电企业经营中,实现将分布在不地理位置、不同发电机组DCS的实时数据上传到区域发电企业生产调度管理系统中,为企业提供发电机组实时信息监视,及时掌握发电机组运行状态,对提高企业管理水平十分重要。本文简单介绍了OPC、Winsock API技术标准,并在满足《电力二次系统安全防护规定》下,设计了基于OPC、Winsock API技术的通用远程数据采集系统,并在实际中得到了应用。     

Short-circuit Analysis in Large-scale Distribution Systems With High Penetration of Distributed Generators

In this paper a short-circuit computation (SCC) procedure for large-scale distribution systems with high penetration of distributed generators based on contemporary technologies is proposed. The procedure is suitable for real-time calculations. Modeling of modern distributed generators differs from the modeling of traditional synchronous and induction generators. Hence, SCC procedures found on the presumption of distribution systems with only traditional generators are not suitable in nowadays systems. In the work presented in this paper, for computation of the state of the system with short-circuit, the improved backward/forward sweep (IBFS) procedure is used. Computation results show that the IBFS procedure is much more robust than previous SCC procedures, as it takes into account all distribution system elements, including modern distributed generators.      

巨型风电并网系统的协同自律控制

巨型风电场并网发电的调度和控制是我国电力系统发展亟需解决的关键难题之一．本文提出了风-水-气协同自律控制的理念和理论,给出了消纳巨型风电的两种基本调度和控制策略,即基于智能调度自动化系统（smart energy manage system,SEMS）的集中式控制和基于协同自律控制的调度策略．本文对比分析了上述两种控制策略的适用情景,指出后者更加合理和高效．进一步,本文探讨了发展基于协同自律控制的风-水-气联合调度系统所需关键技术,试图为解决我国巨型风电并网发电调度难题给出一种方略．