石油钻机直流电驱动系统的谐波影响及其解决方案

论述了石油钻机系统电流与电压的谐波特性及影响 ,并提出一种方法以解决钻机现场录井电源与计算机电源的受干扰问题     

高压抗燃油的特点与运行维护分析

简述 2 1 5 MW机组高压抗燃油系统的概况 ,介绍了三芳基磷酸酯抗燃油的性能 ,分析了抗燃油运行中酸值升高的原因 ,提出了日常维护和解决问题的措施     

微网高渗透对电网稳定性的影响分析

微网对电网的渗透改变了电网中能量传递的单向性,对现有电网的稳定性产生较大影响.分析不同渗透率下微网对电网电压稳定和功角稳定的影响,通过标准EPRI36节点测试平台进行数字仿真验证,得出允许的最大渗透率,并进一步讨论了影响渗透率的主要因素,为微网中各分布式发电的最优能量匹配和提高微网并网时电网的可靠性、稳定性提供一定的理论依据.     

电力系统谐波影响及治理探讨

对于产生大量谐波的用户,在用户变的低压侧加装滤波装置。改变部分运行、接线方式,减小谐波的产生、叠加、放大、产生危害的机会增加电网的短路容量、提高电气设备的短路比,来降低谐波对同一电网上其他设备的影响。     

库底饱和淤积砂层对高拱坝地震反应的影响研究

本文中采用时域显式有限元方法,将库底淤积砂层模拟为重流体,以小湾拱坝为例,分析可压缩库水条件下库底饱和淤积砂层对高拱坝地震反应的影响。计算结果表明,从总体上来说饱和淤砂层的存在对高拱坝地震反应影响较小,但是仍有一些局部反应的变化值得注意。     

The influence of pressure and conductivity on the pulsed breakdownof water

The influence of hydrostatic pressure and liquid conductivity on the dielectric breakdown of water solutions subjected to high amplitude electric fields of sub-microsecond duration has been investigated. Well-defined pulses (80 kV, 3 ns risetime, 100 ns duration) have been applied to a gap (0.4 to 2.1 mm), between Rogowski profile electrodes (thus ensuring a uniform electric field), containing de-ionized water (non-distilled, and distilled and ultrasonically treated), sodium chloride solutions (0.001 to 1.0 molar), or magnesium sulfate solutions (0.01 to 0.1 molar). Breakdown in these liquids has been studied at pressures from atmospheric up to 40 MPa. The inter-electrode potential and the current response were measured indicating the time lag to breakdown, breakdown voltage, and temporal characteristics of the breakdown process. The breakdown time lag increases with increasing pressure, and is insensitive to the liquid conductivity. These findings have relevance to the ongoing discussion concerning `thermal' vs. `electronic' mechanisms for dielectric breakdown in liquids. In particular, the results suggest that breakdown evolves via `bubble' formation by field emitted currents near asperities on the cathode, and that the time for the change in liquid conductivity as a result of breakdown is limited by processes other than ionization growth (due to electron impact ionization of molecules in the `bubble') of prebreakdown electron currents     

消泡剂对隔板及蓄电池性能的影响

采用几种消泡剂对经表面活性物质处理过的烧结ＰＶＣ、ＰＰ隔板及其对蓄电池性能的影响进行了 试验,并讨论了试验结果。     

Influence of liquid temperature and electrode size on insulated breakdown characteristics in saturated superfluid helium

The dc breakdown strength and pulsed breakdown time lag of saturated superfluid liquid helium (HeII) at 1.4 and 1.85 K are measured over a wide range of electrode sizes and applied field strengths. The results of the measurements are statistically analyzed by using Weibull distribution functions. It is found that the area effect is dominant for dc and pulsed breakdown rather than the volume effect as in the case of liquid helium of 4.2 K (HeI). The shape parameter in the Weibull distribution function for dc breakdown strengths of HeII is smaller than that of HeI. As a result, dc breakdown in superfluid helium can take place in a wider electrode area than in normal liquid helium, while no remarkable differences in breakdown areas are observed between 1.85 and 1.4 K. On the other hand, the statistical time lag in HeII becomes shorter with a decrease in temperature. According to the Fowler‐Nordheim theory, it is suggested that a higher electron mobility in HeII may increase the field‐emitted electron kinetic energy to trigger liquid breakdown with a higher probability. © 1999 Scripta Technica, Electr Eng Jpn, 128(3): 16–23, 1999     

冲击负荷对电能计量的影响

针对现场的电能计量纠纷，提出了冲击负荷对电能计量的影响问题，同时设计了一套实验方案，定量对冲击负荷对电能计量的影响作了分析，帮助现场解决了电能计量纠纷，由此提出电能表的响应速度应作为衡量电能表质量的一个重要指标的问题。     

电驱动钻机转盘控制研究

简要介绍了钻机特殊工况下,转盘调速/转矩控制间结构转换的实现方法。     

对谐波影响下的电能计量方式的探讨

为保障电力企业经济运营效果和促进用户对谐波的治理，通过分析电力系统谐波对电力营运企业电能计量的影响，提出对基波电能与谐波电能分别计量的计量方式，并介绍了电能计量装置技术改造的方法，举例分析了技术改造的经济效益。     

胶体电解质性能研究及在铅蓄电池中的应用

简述了胶体电解质的配制方法;提出好的胶体电解质应具备电导率高、强度合适、凝胶时间长、微观状态颗粒较小、网络结构致密等特征;主要探讨了二氧化硅及硫酸含量、温度等因素对胶体电解质物化性能的影响;研究了不同配方胶体电解质应用于铅蓄电池时的电性能。结果表明:胶体电导率受二氧化硅含量的影响很小;胶体强度主要受二氧化硅含量控制;随着二氧化硅含量增加,凝胶时间大大缩短且凝胶时间与温度遵循阿累尼乌斯公式;当然,从电镜扫描结果来看,二氧化硅含量为6.0%左右时其胶体的微观结构较佳;不同配方的胶体电解质应用于铅蓄电池时其内阻、初始容量、大电流放电性能等方面存在差别。     

温度对电动汽车直流充电机计量性能影响的研究

自电动汽车直流充电机被国家市场监督管理总局列入强制管理的计量器具目录后,其电能计量性能越来越得到社会的关注。直流充电机实际使用环境温度变化范围比较大,温度变化对直流充电机的计量性能有一定的影响。文中结合直流充电机电能计量的工作原理,选取温度作为影响量,利用搭建的温度影响仿真测试平台,测量直流充电机计量单元在不同温度下的计量准确度。分析了直流充电机温度影响规律,提出了基于分段线性插值法的直流充电机计量单元温度补偿模型。实验结果表明,经过温度补偿的直流充电机电能计量准确度得到明显的提高,验证了分段线性插值补偿方法的准确性和适用性。     

电动汽车动力电池高压电测试系统的研究

以燃料电池汽车为例,介绍了电动汽车的高压系统结构,根据汽车和人体安全标准,提出了适合电动汽车的高压安全标准.在分析了电动汽车高压系统等效电路模型的基础上,基于虚拟仪器以及CAN总线技术开发了电动汽车高压电安全测试系统,可以对电动汽车高压系统状态和电气电路参数进行实时检测.最后给出了相应的测试结果,证明了此系统的准确性与通用性.     

Investigation of the dependence of DC insulation resistivity ofultra-clean polyethylene on temperature and electric field

The present work aims at determining the dependence of the DC insulation resistivity on temperature and electric field for a super-clean low density polyethylene (LDPE) used in manufacturing modern high voltage AC cables. Resistivity measurements were made using relatively thick (~2 mm) samples at different temperatures and DC electric fields. Based on the present experimental data, a mathematical model for the relationship between the insulation resistivity of the polymer, temperature and electric field was determined using: (i) computer curve fitting techniques, and (ii) artificial neural networks (ANN) method. Comparison between the present results and previous measurements, using less clean grades of LDPE, indicates that the inherent dependence of the DC insulation resistivity of LDPE on temperature and electric field has not been appreciably improved by using an ultra-clean polymer. It is concluded that the successful utilization of LDPE for HVDC cables will require the modification of such dependence     

电力产业政策的制定及对电力设备制造行业的影响

在国家的高度重视和大力支持下,经过电力行业和设备制造行业的团结协作、共同奋斗,2004年我国 发电设备容量已达到4.4亿千瓦。从电力工业快速发展的实践来看,电力行业与电力设备制造行业之间存 在着紧密的联系,两者之间相互促进又相互制约。制定和实施"十一五"期间电力工业发展产业政策(以 下简称电力产业政策),必将对电力设备制造行业产生全面的、深远的重大影响。     

电压闪变影响下的功率计算模型与电能计量方法研究

当前针对谐波电能计量技术开展了大量研究,而含有电压波动与闪变畸变信号影响下的电能计量技术研究较少。文章构建了电压波动与闪变影响下的功率数学模型,推导功率的简化计算式,提出了基于小波包分解与重构的电压波动与闪变下的电能计量方法;利用Db45小波函数,采用5层小波包变换,进行电压波动与闪变影响下稳态、非稳态信号的有功与无功电能计量的仿真分析,实验结果证明了算法的可行性与准确性。     

The influence of interconnection of electric power systems on load characteristic and frequency regulation

In China, national interconnected power system is a necessary trend for the development of electric power systems. Due to the time lag and temperature difference in different areas, the peak load discrepancy will influence the ratio of the regular components to stochastic components of system loads when power systems in different areas are connected. The power spectral densities of the regular loads and the stochastic ones were analyzed and compared in this paper, and how the load change works on the frequency regulation was also described with illustrations. The conclusion emphasized that primary frequency regulation is still relatively significant to the security of operating a huge interconnected power system, even if the system frequency could be controlled well through secondary regulation.