共查询到20条相似文献，搜索用时 244 毫秒
1.
发电机正常运行,发电机转子绕组及励磁系统对地是绝缘的。因此,当转子绕组或励磁回路发生一点接地时,不会构成对发电机的危害。但是,当发电机转子绕组出现不同位置的两点接地或匝间短路时,很大的短路电流可能烧伤转子本体;另外,由于部分转子绕组被短路,使气隙磁场不均匀或发生畸变,从而使电磁转矩不均匀并造成发电机振动,损坏发电机。为确保发电机组的安全运行,当发电机转子绕组或励磁回路发生一点接地后,应立即发出信号,告知运行人员进行处理;若发生两点接地时,应立即切除发电机。因此,对发电机组装设转子一点接地保护和转子两点接地保护是非常必要的。 相似文献
2.
水电厂发电机机组在运行过程中会出现转子绝缘故障,一般故障情况为发电机转子绝缘降低,这对发电厂的正常运行造成了严重影响。需要立即停止发电机运行,进行检修。造成发电机机组转子绝缘低故障的原因通常有：机组碳刷运行时,由于研磨过快,从而研磨出大量细小的碳粉,碳粉附着就会出现绝缘状况;轴承室密封不严,润滑油溢出,温度过高时,就会形成油雾,油雾和碳粉混合就会形成油泥碳粉,从而造成绝缘降低。对这些原因进行分析,通过技术改进,进行绝缘支撑、油雾过滤器的改造、以及加装油雾和碳粉吸收装置,保证水电厂机组的安全运行。 相似文献
3.
在军粮城发电厂#6发电机停机进行检修后.电气运行人员用1000V摇表测转子绝缘电阻,结果为150MΩ.置换氢气后,电气运行人员复测转子绝缘电阻,结果显示为零.在采用包括发电机转子风干,通热空气加热等多种方法进行转子干燥均无效的情况下,采用定速、通电对转子加热进行干燥,获得成功. 相似文献
4.
5.
在火力发电机组故障中,发电机转子故障占了很大的比例。为了保证发电机的安全运行,延长发电机的使用寿命,在提高检修质量的同时还需要采取一系列的措施来预防故障的发生。本文对新庄孜电厂发电机转子的故障进行了分析总结,提出了预防措施,并取得了一定的效果。 相似文献
6.
在发电机的各个环节中,转子绝缘的转速高、运行温度高,转子绕组在离心作用下常因摩擦导致绝缘损伤,此外,冷却空气会将水气、炭灰、油污以及粉尘等带入转子并存积,从而使得绝缘电阻值下降,因此,转子绝缘属于较为薄弱的环节,需要加以保护。文章对发电机转子接地故障进行了简要介绍,从实例出发,对某水电厂的发电机存在的接地故障原因进行了具体分析,并在此基础上提出了防范措施。 相似文献
7.
发电机一般应在其额定值范围以内运行,这种运行是安全的。但有时也可能遇到某些特殊情况,如定子或转子电流超过额定值(过负荷)、异步运行、不对称负荷等等,这些都属于同步发电机的异常运行或称同步发电机的非正常工作状态。研究这些运行情况对电机和电网的影响也是很重要的,由此可找出允许继续运行的条件和要求,以提高电力系统运行的可靠性。 相似文献
8.
碳刷主要是连接发电机转动部分和静止部分的,并将整流柜输出的电流供给发电机转子,但是在运行中由于通风不良、机械摩擦、接触不好等因素的影响,会引起发热,危及发电机的安全运行。文章通过分析碳刷发热的原因,提出解决措施。 相似文献
9.
发电机失磁是指发电机的励磁突然全部消失或部分消失。引起失磁的原因为励磁回路开路、短路或励磁机励磁电源消失或转子绕组故障等。发电机发生失磁故障后,转子出现转差,定子电流增大,定子电压下降,有功功率下降,无功功率反向并且增大;在转子回路中出现差频电流等主要特点。构成发电机失磁保护的主要判据有：转子低电压,低阻抗,系统低电压。为了确保电力系统及发电机的稳定运行,根据浑江发电公司200MW汽轮发电机组的实际情况探讨发电机失磁保护装置的构成原理及整定计算方法。 相似文献
10.
11.
本文对湛江电厂一台300MW汽轮机,在启动、运行中振动偏大的突出问题进行了探讨,介绍了振动原因分析、诊断和处理过程。 相似文献
12.
本文采用改进的模糊控制自适应遗传算法,以克服采用定值常量作为交叉和变异概率所带来的早熟现象和效率相对较低的问题,尽量避免陷入局部寻优。本文采用三机、十三机系统进行电力系统有功优化仿真,结果表明,改进的算法具有更好的寻优效果。 相似文献
13.
One challenge of generating a liquid aerosol is finding an efficient way to break up bulk amounts of the compound into micron-sized droplets. Traditional methods of aerosol generation focus on the principle of creating the liquid droplets by blowing air at high speed over or through a liquid. In this study, a novel micropump droplet generator (MDG) is proposed based on a microfluidics device to produce monodisperse droplets on demand (DoD). The micropump design was employed to both pump the fluid into the air and to encourage droplet breakup and aerosol formation. Computational simulation modeling of the new MDG was developed and validated with comparisons to experimental data for current generators. The device was found to produce an aerosol similar to a vibrating orifice DoD device. Most importantly, the input power required by the newly proposed device (MDG) was several orders of magnitude below existing DoD generators for a similar droplet output. Based on the simulation results obtained in comparison with current DoD generators, the MDG device performed effectively at higher frequencies, smaller nozzle diameters, and regardless of the liquid viscosity of the solution. 相似文献
14.
本文对江华县沱江地区低风速区的喇叭口地形的风能资源进行了计算和分析表明：该地区风能资源较丰富，有一定利用潜力和开发价值，为湘南地区利用风能资源提供了科学依据。选用一台200W风力发电机在江华县沱江地区进行连续半年应用试验证明，1、小型风力机的发电量可以满足县级 风能资源、风能密度、风力发电机 相似文献
15.
《Journal of The Franklin Institute》2022,359(15):7775-7795
In this paper, an adaptive control strategy is proposed to address the synchronization issue for weakly damped generators under topological uncertainty. A singular perturbation analysis is then adopted for strongly damped generators and a compensation control scheme is subsequently given to maintain synchronization under topological changes. Theoretical proof is laid out for the validity of the proposed control scheme. Besides, a power sharing strategy is supplemented for strongly damped generators based on the designed controller. Finally, simulation studies are carried out to verify the effectiveness of the control strategies. Results show that synchronization can be swiftly restored even when the power grid suffers a fatal topological change. The power sharing property can be achieved under the given restriction with the proposed controller. 相似文献
16.
Through the coupling of commutator machines, self-excited alternating power can be spontaneously generated with no external electrical excitations. Standard frequency- domain analysis is applied to the various equivalent circuits for each configuration. Conventional series and shunt self-excited generators are shown to have a single pole in the right-half s plane, indicating growing exponential solutions, whereas coupled generators are shown to have a pair of complex conjugate poles in the right-half s plane, indicating overstable modes, which oscillate as they grow, resulting in self-excited two-phase alternating power generation. Because of this interesting result, the analysis is extended to consider N-coupled generators which shows the existence of many overstable modes, resulting in multi-frequency, multi-phase power generation. The existence of electromechanical alternating self-excitation is demonstrated with the periodic speed reversals of a separately exited d.c. motor, which has its armature in series with the field and armature windings of a generator. Experimental results are presented which indicate that the linear circuit representation is appropriate for the onset and early time interval of these self-excited machines. The magnetic saturation characteristic limits the exponential growth so that a steady state results. These devices are of use in low-frequency, high-power applications, as well as serving as a model for other spontaneous mechanisms in nature. 相似文献
17.
2012年《火电厂大气污染物排放标准》 （GB13223-2011）正式颁布,从2014年7月1日起,火电厂污染物排放必须符合新的限值指标：SO2小于200mg/m3、NOx小于200mg/m3、烟尘小于30mg/m3.大量燃煤电厂锅炉面临着降低NOx排放浓度的改造.遵循“先降后脱”的原则加装脱硝装置时,需要对锅炉钢架、省煤器和空预器之间的烟道、空预器、引风机以及相关的烟风管道进行必要的改造. 相似文献
18.
设计了一种T形单色器冷却方案,相比传统的底冷方案,新设计中晶体面形可以通过参数优化得到控制.T形单色器冷却方案适用于功率密度 0.5W/mm2 以下,总功率在 1 0 0W左右的功率条件下 相似文献
19.
双边竞价电力市场中,设计一种兼顾激励发电商减少市场力和污染排放的机制已经成为进一步深化改革的关键环节.本文鉴于电能生产和污染排放的内在联系,依据电能生产单位排放量,把电力产品分为两个等级,并分别构建了不同的电力市场,进而提出一种基于双市场的电能与环境协调激励减排机制.采取随机高低匹配机制竞价,且政府在不同的电力市场中采取对应的策略激励发电商减排.仿真结果表明,与单一市场相比,双市场的协调激励减排机制采用电力产品差异化方式干扰了发电商之间的共谋信息,从而达到激励发电商减少市场力和污染排放的双重效果. 相似文献
20.
A method has been presented in recent papers for deriving precisely stabilized waveform generators by relating them to second-order conservative oscillators. The present paper suggests a method for considerably generalizing the previous class ofgenerator models. This should enable the development of a larger variety of waveform generators with ease and flexibility. The new method is analyzed and is shown to possess implications to theoretical biology and other fields. 相似文献