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随着能源危机与环境问题的日益加剧,世界各国将重点逐渐转向可再生能源的大规模开发与利用.针对大规模可再生能源接入传统交流电网带来的稳定性问题,参考国内外直流电网技术研究成果,深入分析直流电网的特点和适用性,提出利用直流电网网架结构在我国发展大规模可再生能源.通过对比分析传统特高压交直流输电与直流电网技术的特点和适用范围,深入探讨中国直流电网未来发展模式,并指出了直流电网目前亟待解决的关键性问题. 相似文献
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消纳能力提升,微电网推动可再生电力发展
能源枯竭和环境保护的双重压力,驱动电力行业将未来发展重心转向清洁的可再生能源.能源经济正在经历变革性的转型,以太阳能和风能为代表的绿色可再生能源发电量比例逐年增加,可再生能源利用更加分布化,产消者界限日益模糊.微电网技术可充分促进可再生能源与分布式能源的大规模接入,实现对负荷多种能源形式的高可靠供给,为高效利用新能源电力提供了重要的技术方向. 相似文献
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目前,电网缺乏对分布式能源及其所接入低压配电系统的有效量测,难以分析可再生能源大规模接入给配电网运行带来的显著不确定性.电力物联网技术可突破传统量测方式的瓶颈,应用于含可再生能源配电网的多级协调运行及可再生能源广域消纳.面向电力物联网的建设,阐述了可再生能源的状态感知、数据采集与处理过程.然后,利用物联网感知信息,从用... 相似文献
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《Power Delivery, IEEE Transactions on》2006,21(2):584-590
Based on the field-circuit equivalence concept, the equivalent circuit to analyze the voltage distribution of a 500-kV dc transmission-line voltage divider under impulse voltages has been developed. The hybrid finite-element analytical approach is applied to extract the capacitance and inductance parameters of the equivalent circuit, and the Milne method is used to solve this complicated circuit. The voltage distribution along the resistor coils of the divider under impulse voltages is calculated and its nonuniformity is discussed. The analysis results are in good agreement with the measurement results. The selection of capacitors parallel with the resistor turns to improve the voltage distribution along the resistor coils is studied, and the optimal selection of these capacitors is suggested. 相似文献
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A method for compensating a resistor divider for measuring impulse voltage is presented. The compensation is achieved by means of an analog circuit connected across the low-voltage arm of the divider. The compensation circuit consists of two cascaded proportional differentiators with adjustable circuit parameters. A 46.2 kΩ shielded resistor divider system with 75 ns response time was compensated using this method. The unit step response time measurements showed that the compensation network reduced the response time of the system to 13 ns. The compensated measuring system was also shown to function properly under both full and chopped impulse voltages. The method can also be used for compensating resistor dividers without the shielding rings 相似文献
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雷电冲击试验中的直流电缆为大电容试品,试验回路中电感对冲击波形的影响不可忽略,冲击电压发生器电阻参数设置不当将会导致波形过冲和振荡,为此提出一种基于优化模型的雷电冲击电压试验波形参数控制方法。首先,对试验回路进行理论推导,并分析波前时间和过冲率之间的关系,在此基础上引入一个可用于表征波形过冲率的变量Δ_m;其次,以波前时间最小为目标函数,通过限制Δ_m的数值对波形过冲率进行约束,建立电阻参数优化模型;最后,设置不同的Δ_m对模型进行求解,并通过仿真计算和实际试验验证其有效性。结果表明,随着Δ_m设置值的增加,过冲率呈上升趋势,波前时间呈下降趋势,优化模型能够对波形参数进行有效控制。为确定Δ_m的合理设置范围,研究了不同试品电容、不同回路电感下Δ_m设置值对过冲率、波前时间的影响。结果表明,Δ_m取值为0.9~1时,能够保证波形过冲率不超过标准规定的10%。 相似文献
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Jinliang He Shanqiang Gu Shejiao Han Shuiming Chen Guozheng Xu 《Power Delivery, IEEE Transactions on》2006,21(2):577-583
It is essential to extract the stray parameters accurately and efficiently in analyzing impulse responses of a power apparatus. In this paper the stray capacitances and stray inductances of a 500-kV dc transmission-line voltage divider are extracted by the hybrid finite element-analytical approach, and the corresponding equivalent circuit for analyzing the impulse voltage response of the voltage divider is established. According to the discussion of the results of the extracted stray parameters of the voltage divider, reasonable simplification of the equivalent circuit of the voltage divider is made. In addition, the influence of the insulating housing and the electrical insulation oil on the stray capacitances of the voltage divider is discussed. 相似文献
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新型冲击电阻分压器的高压臂电阻是按电场强度分布设计的,且置于绝缘油中。这种分压器可作到标称电压为600kV,分压器本身的响应时间为8.2ns。在带293Ω阻尼电阻及2800mm引线的测量系统中响应过冲为15%。 相似文献