This paper is concerned with development and optimization of strategies for direct wind power supply to industrial consumers based on big data analysis, for the purpose of achieving economic benefit for both wind power generation companies and industrial enterprises. A basic database was established, which contains historical data of wind power output and industrial electric load, as well as meteorological parameters that have significant influence on wind velocity and social parameters that are strongly related to production of industrial companies. A combined model based on cluster analysis and Back Propagation Neural Network algorithm was built for characterization and prediction of wind power output and industrial load, and MapReduce algorithm was utilized to achieve big data analysis process. The effectiveness of recommended strategies is validated through case study which considered five typical industrial companies and fifteen wind farms in northeast of China. The result shows that the recommended strategies can achieve extra economic benefit of roughly Ұ 200,000 per year in theory.

The fiber optic current sensor (FOCS) is susceptible to external temperature in actual operation, which will lead to its accuracy deviation, even malfunction. In order to improve the temperature stability of FOCS’s ratio error, a temperature compensation method based on RBF neural network is established by taking the temperature as input and the ratio error as output to the network. Compared with BP neural network, the simulation results show that the temperature compensation model based on RBF neural network has better accuracy whose prediction error is less than 3%. At the same time, the experimental results show that the drift deviation of ratio error can remain as low as ±0.1% in the range of -40 °C to 70°C, and the 0.2S-level accuracy of GBT20840.8 standard can be achieved.

The engineering application number of fiber optic current sensor (FOCS) is decreasing year by year since 2012 in China due to its reliability problems. However, the researchers and related enterprises have also made some constructive attempts on the study of fault diagnosis of FOCS. In this paper, the application status and the common fault modes of FOCS are analyzed. Three ways to diagnosing the soft and hard fault of FOCS are reviewed, including based on analytical model, on signal processing and on knowledge. Finally, the research direction of FOCS fault diagnosing is prospected. It is concluded that the diversified and intelligent fault diagnosis method based on knowledge has more advantages compared with the other two methods. In addition, the development of FOCS for integrated optical path is of great help in improving its reliability and will be a research hotspot in the future.

The fiber optic current transformer (FOCT) is affected by complex environment in actual operation which will lead performance deteriorate or even malfunction. This paper introduces the application status and common fault modes of FOCT, and a fault diagnosis algorithm of FOCT based on Wavelet-Allan variance is presented. Wavelet transform is used to identify the jump signal for the mutation fault diagnosis, and Allan variance analysis is used to analyze the noise distribution for the gradual fault diagnosis. By combining the two methods above, the condition monitoring and fault diagnosis of FOCT can be realized without changing the structure of the original transformer or adding additional detection equipment. This method is proved to be effective and accurate by diagnosing faults from FOCTs in substation.

The HVDC circuit breaker is a key component of the multi-terminal DC (MTDC) transmission system. The paper proposes a novel Hybrid HVDC CB with the vacuum interrupter (VI) and SF6 interrupter (GI) in series. The artificial current zero method is used to produce current zero while the follow current loop is firstly introduced in order to achieve the “voltage-zero” for the main mechanical switch so that the dynamic electric recovery strength (DDRS) will be improved. The follow current loop is composed of the high voltage thyristors and current limiting element. The mathematic description of the “voltage-zero” and the synergy of the dynamic voltage distribution are obtained. The simulation model of the novel HVDC CB is set up according to the continuous transition model and the modified Mayr arc model with respect to the vacuum arc and SF6 arc respectively. The influence of the parameters of the current-limiting resistors and reactors in the follow current loop as well as the parameters of the oscillation circuit on the “voltage-zero” and the inverted transient recovery voltage (TRV) is gained. This paper provides a new method to improve the breaking capacity of the HVDC CB and supplies the reference for design of the HVDC CB.

介绍了吉林省某500 kV变电站一起三相隔离开关存在的合分闸不同期事故,分析了隔离开关合分闸不同期的原因,经就地分合试验及二次回路检查后,确定事故由A相合分闸二次回路接线错误导致,最后指出在调试中不仅要注意隔离开关分合闸是否到位,还应注意分合闸同期问题.

In order to obtain the effective magnetic arc control method, the synergy effect and the demand of the magnetic arc control in the multi-break VCBs is analyzed. The vital mechanism is the synergy interaction between the dynamic voltage distribution (DVD) and dielectric recovery strength (DRS). Then the test platform of the magnetic arc control in multi-break VCBs is set up and the magnetic arc control system is designed. The influence of the pulse width, control moment and magnetic field on the vacuum arc development and the post arc characteristic is investigated. The different combinations of externally applied AMF are applied to the double-break VCBs to analyze the effect of the AMF arc control on the DVD. The interaction between the magnetic arc control and the post arc characteristic is obtained and the influence of the post arc characteristic on the DVD and DRS is gained. The test results indicate that the mechanism of the magnetic arc control in multi-break VCBs is that the DVD and DRS is affected by the post arc characteristic which is influenced by the arc memory of the magnetic arc control in arcing process. The paper is useful to optimal design of the special serial VCBs and the magnetic arc control of multi-break VCBs.

分布式光伏的并网使地区电网变为多电源发散式网架结构,原有的单电源辐射电网的继电保护受到明显影响,通过电磁暂态仿真(PSCAD)软件建立模型,详细分析了光伏并网后故障位置不同、光伏并网位置不同对配电网保护的影响,及光伏并网对配电网重合闸的影响,发现并网光伏对其上游馈线有汲出作用,对下游馈线有助增作用;在特定故障状态下,光伏并网点及其下游馈线存在孤岛的效应;光伏并网前后其他馈电线路的短路电流无明显影响;同时光伏并网后,其所在馈线存在开关重合失败,存在事故范围扩大的可能.

随着我国环境问题日益突出,电动汽车作为新能源利用的有效途径,是我国当前高新产业和环保产业发展的重点,为了更好的保障和促进电动汽车的使用,建设完善的电动汽车充电基础设施体系势在必行.本文分析了我国充电基础设施规划和布局的几种方法.

With the increasing of penetration of distributed in the smart grid, the problems that the power loss increasing and short circuit capacity beyond the rated capicity of circuit breaker will become more serious. In this paper, a methodology (Modified BPSO) is presented for network reconfiguration which is based on hybrid approach of Tabu Search and BPSO algorithms to prevent the local convergence and to decrease the calculation time using double fitnesses to consider the constraints. Moreover, an average load simulated method (ALS method) load variation considered is proposed that the average load value is used to instead of the actual load to calculation. Finally, from a case study, the results of simulation certify the approaches will decrease drastically the losses and improve the voltage profiles obviously, at the same time, the short circuit capacity is also decreased into less the shut-off capacity of circuit breaker. The power losses won't be increased too much even if the short circuit capacity constraint is considered; voltage profiles are better with the constraint of short circuit capacity considering. The ALS method is simple and calculated time is speed.

Nowadays, with the fast development of power system, gas-insulated switchgears (GIS) has been widely used in high voltage power grids because of compact structure, high reliability and easy-maintainability. At the same time, as the concept of smart grid is introduced, more and more intelligent devices are used in GIS. The disconnector switching operations always produce electromagnetic field emissions and influence the stable operation of electronic devices in GIS. By establishing the enclosure circuit model and the electromagnetic emission model of GIS, the electromagnetic field caused by switching operation is calculated in this paper, and then, the relationships between electromagnetic field and height, grounding points are analyzed. The calculated electromagnetic fields are in good agreement with the measured results.

针对当前以光伏电源为代表的分布式能源的快速发展给地区电网线损带来较大影响的现状,首先对光伏电源并网对线路线损的影响进行相应的公式推导,其次以吉林省光照充足的某地区为例,进行光伏电源并网的线损理论计算分析.分析光伏电源在接入位置、接入电压等级、接入容量这几个方面对地区电网线损的影响,指出光伏电源并网应优先选择电压等级最高的节点,且所接节点负荷的比重尽可能大,电源容量占地区负荷的总量20％～40％为最优线损选择方案.

针对“三北”地区弃风严重的现象,结合丹麦消纳风电的经验及我国调度模式,提出了风电集中供热方案.在综合考虑风电出力的不确定性、系统稳定性等约束条件的情况下建立了含风电集中供热的电力系统优化调度模型,在求解方法上构建了一种免疫遗传-拉格朗日松弛混合算法.通过算例仿真,不仅验证了该算法良好的收敛性和稳定性,也验证了风电集中供热方案对风电消纳的积极促进作用.

The paper established the simulation model of series vacuum arc of Vacuum Circuit Breaker (VCB) with double-break using Magneto Hydro Dynamic (MHD) model. To gain the matching characteristics of series vacuum arc, the influence of series different vacuum gaps and interactional magnetic field was analyzed. The distribution of micro-characteristics was depended on the axial magnetic field causing by different vacuum gaps while the interactional magnetic field between series vacuum gaps was negligible. The research platform of series vacuum arc of VCB with double-break based on transparent vitreous vacuum interrupters was set up. The series vacuum arc was simultaneously acquired by two CMOS high-speed cameras. The out of sync of series vacuum arc extinguishing which was arisen when the VCB with double-break asynchronously opening was proved by arc voltage, arc images and arc area change. With the asynchrony increasing, the probability of out of sync of series vacuum arc extinguishing enhanced. The arc extinguishing of late opening vacuum interrupter was earlier than the early, which was explained by the distribution of micro-characteristic from the simulation. The experimental result and simulation result provided the basis for the practical application.