电气化铁路供电谐波对电能计量的影响研究

本文从谐波对电能计量准确性影响、谐波对电能计量合理性影响两方面出发,采用理论分析、实验室测试和电气化铁路牵引变电所电能表现场测试相验证的方法,研究了电铁供电谐波对计量的影响.对不同谐波功率方向、不同谐波含量情况对计量的影响分别进行了理论分析,并进行了试验验证.依据电铁供电谐波统计资料,在实验室模拟电铁实际负荷情况,研究电铁供电谐波对多种电子式电能表和机电式电能表计量的影响.在电气化铁路牵引变电所现场安装基波电能表,通过一段时间的电量累计,研究了电铁供电谐波对计量影响的实际情况.     

电气化铁路中SVC负序补偿应用技术研究

随着电气化铁路的迅速发展,电铁牵引负荷产生的负序分量及高次谐波,除对牵引供电系统造成危害外,还会造成电力系统负序及谐波污染[1],因而,电铁的负序及谐波危害已成为制约我国电气化铁路发展的重要因素。结合电气化铁路给电网带来的影响,着重探讨电铁负序补偿中SVC的使用问题。根据国外一些发达国家如日本、澳大利亚等国成功将SVC技术应用在电气化铁路的无功和负序补偿案例以及国内SVC负序补偿应用实例,对SVC负序补偿原理及运行方式进行了研究分析,对SVC在电铁负序治理中的应用前景做了初步探讨,以期提高电力系统运行的     

电气化铁路对新疆哈密电网的影响

结合兰新电气化铁路新疆哈密段工程,研究电气化铁路对电网的影响因素,探讨电气化铁路负荷在用电过程中产生谐波及负序对电网的影响,特别是对含风电和电铁同时接入的电网公共连接点(PCC点)电能质量以及风电场的影响。在仿真软件中搭建了新疆哈密地区电网模型,对其影响进行评估和分析,提出治理措施和建议。     

静止无功补偿器(SVC)在宁夏中卫电网的应用研究

深入分析了中卫迎水桥变由于电铁负荷的影响,存在的电能质量方面的问题.在较全面地介绍当前电气化铁路中存在的电能质量问题及我国电铁谐波和负序治理现状的基础上,重点分析了迎水桥变利用静止无功补偿装王(SVC)治理电铁谐波和负序的方案.     

电气化铁路对河源电网的影响分析

从继电保护、运行方式安排等角度,分析电气化铁路对河源电网的影响。要降低电气化铁路对电网的危害,必须加强对牵引站谐波和负序电流的管理。     

黔桂电铁对110kV水任变电站谐波影响分析

为了减少黔桂电气化铁路牵引负荷产生的谐波和负序电流注入电网,降低谐波给供电系统及广大电力用户造成的谐波干扰和影响。分析水任变电站110 kV母线在系统不同运行方式下的谐波、负序、无功变化情况,得出了采用220 kV变电站的110 kV专线主供方式对黔桂电铁电力牵引站供电可降低电铁影响的结论。     

应用ETAP软件分析电气化铁路对电网的影响

电铁负荷属整流负荷,具有非正弦性、不对称性及间断性特点,在运行中会产生大量谐波和负序电流,引起接入点电网电压波动,导致网侧变电站的保护装置、故障滤波装置频繁启动,影响正常生产。为防止电网受到进一步污染,在电气化铁路接入电网前应用ETAP软件对其进行电能质量影响的评估,分析电气化铁路对电网造成的谐波、电压三相不平衡、电压波动等情况。对存在的不符合国家标准的电能质量问题加以整改,在用电设计中同步进行治理设计,根据实际超标容量加装补偿装置,将消谐装置应用于牵引站,以防止电气化铁路负荷对电网影响的进一步扩大。     

应用ETAP软件分析电气化铁路对电网的影响

电铁负荷属整流负荷,具有非正弦性、不对称性及间断性特点,在运行中会产生大量谐波和负序电流,引起接入点电网电压波动,导致网侧变电站的保护装置、故障滤波装置频繁启动,影响正常生产。为防止电网受到进一步污染,在电气化铁路接入电网前应用ETAP软件对其进行电能质量影响的评估,分析电气化铁路对电网造成的谐波、电压三相不平衡、电压波动等情况。,对存在的不符合国家标准的电能质量问题加以整改,在用电设计中同步进行治理设计,根据实际超标容量加装补偿装置,将消谐装置应用于牵引站。以防止电气化铁路负荷对电网影响的进一步扩大.     

西陇海电气化铁路与河南电网

本文介绍了西陇海“电气化铁路”(以下简称电铁)简要概况,给出了其电铁负荷所产生的负序和谐波电流的统计分析结果。在多数运行方式下电铁负荷所产生的负序和谐波电流将会影响电力系统正常运行,特殊运行方式下将造成重大事故。指出了电铁所采取的无功补偿兼滤波措施同实际需要相比是不相适应的,电铁必须进一步完善其滤波措施。为了减轻电铁的负序电流对电力系统的影响,对“电铁”牵引站负荷严加管理保持相对均衡很有必要。同时提出了改进建议。     

三相SVC在电气化铁路电能质量治理中的应用

随着电气化铁路的加速建设,电铁电能质量治理问题日益突出.针对电气化铁路负序电流和三相电压不平衡以及谐波问题,提出了一种基于三相静止无功补偿器( SVC)的电能质量综合治理方案.该方案不同于国内现有的两相式SVC和接入高压侧的三相SVC,将三相SVC接入牵引变电站的低压侧,重点补偿负序和无功,同时治理谐波.仿真结果表明,...     

Electric and magnetic fields

Increasing electrification brings increased human exposures to electric and magnetic fields, commonly called EMFs, and growing evidence suggests that exposure to even low frequency, low energy, electric and magnetic fields may be related to adverse health effects. This paper focuses on magnetic fields and strategies that address them. The challenges faced by scientists in understanding magnetic field interactions with humans, and of mitigating their effects, are discussed. The management of magnetic fields created by power systems are discussed including shielding and interference technology     

农村电工现状调查及解决对策探讨

农村电网容量逐步扩大,农村电工作为电力行业的一个特殊群体,是电力企业与广大农村用户的桥梁和纽带,也是农村电气化事业的生力军。通过对农村电工现状的调查分析,得到现阶段农村电工存在的问题,并提出相应的解决对策。     

Otherwise a mere clod: California rural electrification

Rural electrification reached a highly developed stage in California by the mid-1920s. Farmers tried hydroelectric power, early power companies saw and exploited rural profit potentials, and farming interests assisted in developing the rural market. Elsewhere in the nation, electricity remained an urban phenomenon well into the 1940s. An explanation is given of how and why California accomplished significant rural electrification prior to the rest of the United States. Various reasons considered for this phenomenon include: the location of waterpower sites in relation to population centers, shortages and conservation of other energy resources, technical choices in electric power transmission, economic incentives and load building choices made by power companies, and both private and public support of rural electrification. It is noted that actual rural uses of electricity were also varied, with irrigation and reclamation providing the heaviest electric loads     

Charge behavior in flowing oil in oil/ pressboard insulation system by electro-optic field measurement

The electrical insulation structure of most power transformers is a combination of insulating oil and solid materials. One of the crucial problems we face in transformer operation is flow electrification, which occurs at a flowing oil/solid material interface. Thus, for the transformer insulation design, we need to clarify the now electrification phenomena. In this paper, we measured the electric field strength in an oil/pressboard composite insulation system using an electro-optic method of the Kerr effect. We obtained the time variation of electric field distribution in both flowing uncharged and charged oil. It is notable that we could quantitatively clarify the electric field distortion in flowing charged oil by flow electrification. Furthermore, we measured the leakage current from divided electrodes and derived a charge density distribution along the flow direction. Finally, we quantitatively discussed the electric field distribution and the charge behavior from the measurement results.     

Streaming electrification of thin insulating pipes under electricfield

Streaming electrification under dc and ac electric fields was investigated by using test pipes and oil circulation apparatus. We used two different test pipes, one made of pressboard, and the other of insulating paper. At first, the amount of static charges which flowed into the test pipes was measured without electric field. For the experiment using an insulating paper pipe, when the oil temperature increased, the measured current curve shows a peak. When the velocity increased, the current increased proportionally from the 2nd to 4th power of velocity. For the experiment using a pressboard pipe, the current increased proportionally from the 3rd to 5th power of temperature, and by the 1st power of velocity. Then, we applied ac and dc electric fields on the test pipes and the current from a relaxation tank to ground was measured. The ions in oil carry the charges, so an electric field affects ions in the oil. It makes the mathematical approach to streaming electrification difficult. We know that as the electric field intensity increased, the current due to selective adsorption of the test pipe was increased. The current vs. velocity curve under ac electric field had a peak point in velocity     

Electrification design for modern housing scheme projects

Global electricity access is a key component of the United States Sustainable Development Goals and recently escalating its global efforts to monitor the electrification development progress. To report these efforts, we present a new housing scheme electrification design, planning and examine the impact of urban electrification on individuals and businesses in the community and explore the theory of resource-based entrepreneurship. The target of this design study is to provide an adequate, stable, reliable and economical electrification design to the prospective consumers of the scheme in an acceptance manner. The scope of this study is to cover the required estimates for the project to install and procure equipment and materials for 11 kV distribution lines, low voltage distribution supply networks and necessary measures for electrification of non-electrified areas, full design of cost estimation and power loss analysis of electric distribution networks. Housing scheme design planners can process the information as a design package and create a variety of formats that can be customized to meet the needs of the customers. For example, cost estimates and the contractor logistics can be used in the pre-design phase of the customer schedule. The electrification design method and conclusion of this work are intended to contribute to the improvement of housing scheme electrification design, and particularly useful for the developing nations.     

Electrification: Its Effect on Signaling and Communications

When an operating railroad is electrified, the propulsion power may produce effects on the signaling and communication facilities which require conversion for compatibility. This paper explains the role of signaling and communications in railroading, describing the needs and economic justification. It describes the effects of electrification and the requirements for conversion of facilities. It suggests a systems approach to electrification, on the basis that proper coordination of propulsion power with signaling and communication facilities can materially improve the return on investment for electrification.     

变压器油道内冲流电流的一种计算方法

对紊流态下变压器油道内冲流电流的计算进行了研究。描述油内电荷分布的输运方程是一个非线性方程,不存在精确的解析解。应用文中所给定的绝缘油/纸板界面的边界条件并经过合理的简化,推出了该方程的近似解析解和冲流电流的计算公式。公式能描述油流速度、电导率、油温和外加交流电场对变压器油流带电的影响,所引入的修正量可通过实验数据确定。实验证明,计算公式可以用于预测冲流电流的大小,从而避免了繁重的数值计算,为变压器油流带电的计算提供了一种方便的手段。     

Electrification: The nexus between consumer behavior and public policy

With deepening concerns over climate change, policymakers, electric utilities, environmentalists and others are increasingly championing the idea of ‘electrification,’ or the replacement of fossil fuels with electricity for direct end uses like transportation and space heating. The electric industry sees electrification as an opportunity for revitalizing sales and revenues. The focus of this paper is on consumer behavior and its nexus with public policy for advancing electrification.     

电气化铁路负荷对电网电能质量的影响

铁路电气化具有运输能力大,综合能源利用率高,节能减排等明显优点,随着科学技术和国民经济的快速发展,我国铁路电气化进入了一个非常快的发展时期。但是,电气化铁路牵引负荷由于其单相运行、整流供电、负荷变化等原因,对所接入的电力系统带来功率因数低、三相电压不平衡、谐波超标、电压波动等严重的电能质量问题。河南地处全国铁路网中心,铁路电气化比例位于全国前列。结合河南电网的情况及电气化铁路发展的特点,讨论了河南电气化铁路负荷对电网电能质量的影响,并给出了相应的解决措施。