The new problem of multi-frequency oscillation and disturbance in new power system seriously threatens the safe operation of power grid. The existing multi-frequency phasor measurement technology can realize oscillation monitoring within 300Hz, centralized storage and monitoring at the master station, and off-line modeling and simulation method is used to evaluate the network risk. The large amount of multi-frequency phasor measurement data in the master station centralized storage and monitoring occupy a lot of resources, off-line risk assessment can not adapt to the real-time change of the power grid conditions. Based on the concept of edge computing, a multi-frequency oscillation collaborative online monitoring and advanced warning scheme is proposed to realize multi-level monitoring and advanced warning for bay-station-regional power grids. Key technologies such as grid bay monitoring, station area monitoring and advanced warning, master-substation coordination and wide-area coordination monitoring and advanced warning are expounded. The correctness and effectiveness of multi-frequency oscillation collaborative monitoring and advanced warning are verified by experiments. It can meet the requirement of re-al-time monitoring and risk advanced warning of multi-frequency oscillation in power grid.

As large-scale integration of photovoltaic power, inverters are widely used in new-type power system, the rich signal including inter-harmonic/harmonic are injected into power grid, it takes new change to the characteristics of power grid, from fundamental signal to wide-frequency signal. The current research is focus on model and simulation analysis of photovoltaic plant and cannot realize the monitoring of harmonic/inter-harmonic. Based on the wide-frequency measurement technology, the consecutive monitoring of wide-frequency signal of the grid connected with photovoltaic plant can be realized, the characteristics of power frequency and non-power frequency signals connected with photovoltaic plant is analyzed. The relationship between typical harmonics and fundamental signal is described, and is compared with other substation connected with photovoltaic plants. It is helpful to improve the understanding about the wide-frequency characteristics of the grid connected with photovoltaic plant, and to provide a guide for the safety operation of power grid.

This article addresses the problem of widespread harmonic frequency in the power grid caused by extensive integration of new energy sources into the new power system, which cannot be accurately measured by existing measurement and control equipment such as PMU. The article comprehensively applies transient quantities, phasors, effective values, and other algorithm models to design a wide-frequency measurement algorithm that supports cross-platform integration and deployment. The algorithm achieves unified measurement of power frequency, non-power frequency components, and oscillating power in the range of 0~2500Hz, enhances the detection capability of measuring devices for wide-frequency electrical quantities with different signal structures, and is deployed in multiple new energy power stations.

The wide-frequency measurement real-time data has large capacity and high density, which is easy to cause network congestion during data interaction between master and substations, and takes up a lot of resources during centralized storage and analysis of master station. Using the concept of edge computing for reference,this paper proposes a technical scheme for the pretreatment and adaptive transmission of real-time data in wide-frequency measurement stations. The substation domain preprocessing result data is obtained by statistical analysis and sent to the master station when the power grid is in a stable state. In the case of grid wide-frequency disturbance, the transmission mode between the master station and substation is adaptively switched, and the wide-frequency measurement real-time data is transmitted as required between master station and substations. It gives the principle of station domain preprocessing and adaptive transmission. Key technologies such as data preprocessing,power grid wide-frequency disturbance monitoring, adaptive transmission mode,and adaptive transmission process are expounded. The experiment verifies the correctness and effectiveness of the station domain preprocessing and adaptive transmission about the wide-frequency measurement real-time data.

Process layer packet is the key segment to realize substation data acquisition and operation control. Due to the lack of unified and standardized configuration for process layer packet parameters, there is large difference in the engineering configuration of parameters. It is difficult to quickly locate the abnormal or fault of process layer equipment and affects the operation safety of substation. This paper analyzes the current status and existing problems of the configuration of process layer packet parameters, puts forward the optimal configuration scheme of process layer packet parameters, discusses from two aspects which are substation topology structure and the number of device packet, focuses on the analysis of substation topology, and discusses the voltage level coding and electrical bay coding combined with the characteristics of grid of China. Based on this scheme, the destination address parameters of process layer packets are optimized, and the specific configuration methods of voltage level number, electrical bay number and multi-cast control block are discussed in detail. The relationship between process layer packet and substation topology is effectively established and APPID parameter configuration is discussed based on this relationship. Finally, combined with the actual topology of 220kV smart substation, the analysis is carried out, which can provide reference for the standardized configuration of parameters of process layer packet in smart substation in the future.

当前电力系统常采用日常小扰动响应在线辨识获取低频振荡模式信息，对大电网低频振荡的分析和抑制具有重要价值。对于低频振荡信息在线辨识给出了两段最小二乘估计方法，与常规递推ARMA方法相比具有较高的迭代收敛速度与辨识准确度。在介绍小扰动下的已知激励响应信号和环境激励响应信号基本原理的基础上，对比得出两种信号在激励与响应、信号成分和数据量大小上存在区别，然后提出低频振荡在线模式信息辨识方案，进一步在10机39节点系统中仿真获取已知激励响应信号和环境激励响应信号，对两种信号的功率谱与辨识结果进行分析对比。分析结果表明，在确定激励位置、观测点选择和响应模式间对应关系时已知激励响应信号的辨识效果更好，在该情况下可以将已知激励响应辨识作为低频振荡信息在线辨识的主要手段。

高比例新能源和高比例电力电子设备的接入,产生了大量间谐波信号,并引发一系列宽频域振荡事件,严重影响了电网的运行安全,现有测量技术局限于工频信号测量,无法实时监测宽频振荡等间谐波信号.文中以《电力系统宽频测量装置技术规范》发布为契机,介绍了宽频测量技术的提出背景、装置功能定位及相关术语定义,从宽频信号的采样频率、数据测量、宽频振荡监测、数据传输以及数据录波等方面讨论了宽频测量装置的功能和性能,论述了装置工程应用的方案、应用场景和应用展望,总结了标准制定中存在的问题及下一步研究方向,为宽频测量装置的工程应用提供指导和参考.

宽频量测技术的快速发展为部分新能源发电并网节点的次/超同步振荡监测提供了有效手段,但是由于测量单元布点限制,难以获得全网的振荡传播和分布.为此,提出了一种基于新能源发电并网点宽频量测间谐波潮流计算的次/超同步振荡溯源方法.给出了次同步振荡频率下间谐波潮流算法的网络模型和元件模型,总结了间谐波潮流计算的详细步骤,通过间谐波潮流计算可得到各个节点的间谐波电压电流分布,进而获得全网次/超同步振荡传播路径.当新能源发电系统次同步振荡传播引发邻近火电机组轴系扭振时,存在扭振机组间谐波等效阻抗突变的特性,从而造成间谐波潮流分布发生变化,根据预想振荡状态下间谐波潮流计算结果与实际宽频量测结果间的不同,可用于新能源发电次同步振荡引发邻近火电机组轴系扭振的溯源定位.最后,基于四机两区域系统和IEEE 10机39节点系统算例验证了所提方法的有效性和准确性.

由于当前电网负荷的电力电子化趋势越来越明显,导致其复杂性、随机性、时变性也显得尤为突出,从而影响了电力负荷模型的准确性.负荷建模过程中为了考虑到不同比例及不同类型电力电子设备的影响,需要进行合理的分类.针对不同类型的电力电子设备具有不同的端口机电特性与谐波特性,对典型负荷设备进行谐波特性分析,进行初步的分类,然后建立详细仿真模型用于获取大量的各种随机场景下的特征数据,分析其谐波特性,并通过模糊C均值聚类(Fuzzy c-means,FCM)方法进行分类调整.通过谐波模拟数据集,验证本方法用于电力电子负荷构成成分分析及分类的合理性与有效性.

大量电力电子设备接入电网导致电网振荡频繁发生并使其逐步向宽频域振荡发展.首先,分析了广域测量系统监测技术在振荡监测存在的问题和局限,讨论了现有间谐波测量算法存在的不足,提出了电网宽频振荡实时监测技术方案.然后,论述了振荡实时监测的总体架构和关键技术,从高频采集及滤波、宽频信号分类处理分析、振荡告警及长录波、站域存储与分析和信息传输等方面对宽频振荡实时监测的关键环节进行了分析.最后,对宽频振荡实时测量的效果进行了仿真验证,验证了所提方案的可行性,并对其工程实施方案进行了论述.

With the large-scale application of power electronic devices on the “Source-Net-Load” side, the power grid has been injected a large number of harmonics and inter-harmonics and is becoming electronic power systems. The existing measurement devices cannot meet this challenge. Taking the abnormal fluctuation event of bus voltage measurement value of a UHV power plant along the line as an opportunity, the wide frequency measurement device is used to analysis and solve the problem. The high-order harmonics has been found in the power grid by the device and its distribution is related to the operation mode of the main transformer. Based on this, we located in and clarify the reason, the measurement function of the measuring device is disturbed by high-order harmonic aliasing. The mechanism of measurement data fluctuation caused by the interaction between high-order harmonic aliasing component and fundamental component at a specific sampling frequency is analyzed. Though the simulation with MATLAB, the characteristics of field data are reproduced to verify the analysis conclusion. On this basis, it is pointed out that high-order harmonics in UHV should be monitored and concerned. The technical measures and suggestions are given from the perspectives of device R&D, detection, filtering and wide-frequency measurement monitoring, that can improve the quality of measurement data, timely understand the new characteristics of power grid and ensure the safe and stable operation of power grid.

With the development of power grid technology, the scale of modern power grid is expanding, and the operation mode is becoming more and more complex. Low frequency oscillations are always important factors threatening the security and stability of power grid. It is difficult to distinguish the negative damping mechanism oscillation from the forced power oscillation. In recent years, the rapid development of the third generation artificial intelligence technology provides a technical basis for the identification of power oscillations with different mechanisms. This kind of artificial intelligence technology, represented by deep learning, has made remarkable achievements in classification, aggregation and other fields. This paper studies the construction of deep learning model and its application in the discrimination of different oscillation mechanisms, and proposes a recognition method. This method is based on the deep belief network of negative damping oscillation and forced power oscillation to build a deep learning model, which can be applied to feature extraction of negative damping oscillation and forced power oscillation.

针对电力电子化电网电气量的宽频特征,设计了多功能宽频测量装置.基于高速同步采样优化,该装置集成宽频振荡检测、同步相量测量和宽频(间)谐波测量等功能.该装置综合运用暂态量、相量、有效值等算法模型,可提高对于不同信号结构宽频电气量的监测能力,兼顾平稳和非平稳工况,实现0～2500 Hz范围内工频、非工频分量和振荡功率的全面检测,为宽频电气量的产生机理、传播路径、分析控制等研究提供针对性的数据.文中实现的多功能宽频测量装置已通过测试并试点应用.

针对现有变步长扰动观察法在模型复杂影响响应速度和环境适应范围的问题,提出了基于功率差的变步长扰动观察法.从光伏发电的数学模型出发,对算法进行了理论推导,证明了功率控制在响应速度、适应范围的优势.通过仿真对本方法与定步长、变步长、模糊控制方法进行了对比分析,验证了算法的性能.所提出的算法易于工程实现,可为今后光伏系统最大功率控制提供技术参考.

2019年8月9日,英国电网发生大停电事故,造成英国伦敦在内的部分城市停电,影响人口100万左右.文中对该事故进行总结分析,为我国电网的安全稳定运行提供借鉴和参考.首先,对此次新能源电厂发生的振荡事件进行分析,总结此次振荡事件所呈现的典型特征,梳理其存在的遗留问题;其次,对以该事件为代表的一系列由新能源厂站触发的振荡事件进行思考,论述新能源大规模并网后电网振荡呈现的新特点;最后,针对现有测量技术在振荡监测上存在的不足,提出采用宽频测量技术实现振荡实时监测,并给出具体的工程实施方案,为电力电子化电网振荡的实时监测提供参考.

Wide-frequency measurement device for monitoring electrical signals in the range of 0 Hz to 2500 Hz has been researched and applied. A large number of unprocessed wide-frequency measurement data is directly transmitted to the master station, which brings difficulties to the master station interaction and storage. This paper draws on the edge computing ideas of calculation, storage, and preprocessing near the data source, and designs a wide-frequency measurement system structure based on the perception layer, edge layer, and application layer. The data flow and functional architecture of the wide-frequency measurement station domain storage and analysis device at the edge computing layer are explained in detail. The storage and query of wide-frequency real-time data, event recording files, continuous recording data, and alarm information are studied. Wide-frequency measurement data is pre-processed by the elastic period. Based on the harmonic and inter-harmonic time-division transmission model, real-time and offline data can be interacted with the multi-plane master station at the same time. Finally, a wide-frequency measurement station storage and analysis prototype based on edge computing is developed, which achieved engineering applications and achieved good results.

Frequency is a particularly important operating parameter in power systems, and power system frequency characteristics analysis lays the foundation of frequency stability analysis and control. Different simulation models will have different effects on the results of simulation calculation, especially the accuracy of load model will play a vital role in the final simulation results of power grid. In this paper, typical static load model and induction motor model are introduced and frequency characteristics are analyzed. A parameter aggregation method of load model based on adjusting performance weighting is proposed. The effectiveness of the load equivalence method is verified by an example of Fujian power grid.

变电站中广泛应用的智能电子设备(IED)存在软件更新、硬件更换、应用更新及配置更改的问题。为了加强对于IED设备的管理以及故障情况的分析,文中提出了基于构件技术记录IED软硬件及配置参数等备份信息的版本管控系统设计方案。基于对智能变电站IED运行及改造过程中需要备份管控的关键信息的归纳和总结,设计了主子站信息交互的版本管控系统架构及管控流程。设计了用于描述IED管控备份信息的版本描述文件范例,并给出了实际应用范例。实验测试结果验证了版本管控技术方案的可行性。

高压直流输电、柔性交流输电系统(FACTS)的应用以及新能源大规模并网为电网引入了大量电力电子设备,给电网注入了大量的间谐波和高次谐波等宽频信号,使得电网逐步呈现电力电子化的发展趋势.现有的测量设备重点关注工频信号测量,无法应对宽频信号测量所提出的挑战.文中分别从现有测量设备的局限、相量测量单元(PMU)升级改进的局限和高频信号测量的局限三个方面分析了现有测量技术的现状,针对性地提出了宽频测量技术总体方案,设计了总体架构,并讨论了具体实现所涉及的宽频信号范围限定、采样频率选择、数据处理机制设计、数据传输协议和同步对时等关键问题,研发了原型装置并在变电站试点应用,验证了宽频测量技术的可行性.文中研究能够为电力电子化电网提供新的监测手段,保障电网安全稳定、推动新能源大规模应用,同时进一步推动二次设备集成整合,降低变电站建设成本.