大型水轮发电机组保护维护分析与探讨

为了确保大型水电站水轮发电机组高效稳定安全运行,以保证给用户和电力系统不间断地供应电能源,必须进行定期维护检查,及时消除隐患,防止故障停机。本文从分析水轮发电机组的结构和维护检查周期入手,简单介绍了维护检修过程的特点,并以此为延伸,对新兴的模糊专家系统在水轮发电机组中的应用进行探讨,以适应信息化时代发展的步伐,以更高的效率开展大型水电站水轮发电机组的维护检修保护系统进行探讨。     

风力发电机组的运行维护分析

阐述风力发电机组中变流器、发电机叶片、异常振动的运行故障,风力发电机组运行的维护措施,从而保障风力发电机组稳定安全运行。     

水轮发电机组的故障与检修对策

阐述水轮发电机组故障与检修方法，包括安装的监督管理，更好地保证水轮发电机的安装质量，制施工进度的网络图和施工项目明细计划，保障检修实施，制定突发状况的应急措施。     

简析风力发电机组的调试与排故措施

风力发电机组的调试以及故障排除对于系统的稳定运行有着积极的意义.必须结合风机生产车间的实际制造状况以及系统运行的状态,检查测试结果来进行设备的维护与检修.本文详细阐述了风力发电机组的故障种类以及产生恨因,并针对具体的原因采取合理的排除措施,以保证系统的稳定运行.     

水电厂水轮发电机组调速器维护及故障处理

水电厂进行电力生产的重要动力设备就是水轮发电机,水轮发电机在当前的水电发展事业中起到非常大的推动作用。其中调速器是水轮发电机组中调节机组转速的重要部位,只有对调速器的正常运转进行保证,才能够保证水轮发电机组正常的运行以及发电,从而对水电厂的生产效益以及经济效益进行较大的提高。但是在水电厂实际生产中,水轮发电机组中的调速器会经常出现一些故障,会对水轮机组的正常运行产生重要的影响,所以必须加强对水轮发电机组调速器的维护和故障处理研究。本文主要阐述了调速器在水电厂的作用和地位,并且阐述了水电厂水轮发电机组调速器维护及故障处理相关内容。     

电网故障冲击对发电机组的影响及应对措施

在电网运行过程中为了避免对整个电力企业造成更大损伤,需要电力企业的发电机厂具备较强的抗干扰能力,阻止电网故障冲击对发电机组造成的严重影响,形成电网事故故障的进一步扩大恶化,造成大面积大范围的停电检修,以至于为居民的生产生活带来较大的便,基于这种问题重要性,本文主要是着重分析了电网运行中可能存在的故障对发电机组造成的影响分析,进一步探求寻找恰当的应对解决策略,仅供参考.     

几种双馈式变速恒频风电机组低电压穿越技术对比分析

新电网运行规则要求风力发电机组在电网故障出现电压跌落的情况下不脱网运行,并在故障切除后能尽·陕帮助电力系统恢复稳定运行,要求风电机组具有一定低电压穿越能力。由于双馈感应发电机（DFIG）励磁变换器容量有限,电网故障时会产生转子过电流和变换器直流环节过电压,须实行保护和控制。本文对国内外学术界和工程界对电网故障时双馈感应发电机的保护原理与控制策略进行了大量研究。以便具体设计时根据要求合理选择。     

基于MCU的嵌入式风机在线监测系统研究

本文介绍了一种基于多台MCU和一台PC机构成的分布式风力发电机在线监测系统,采用嵌入式数据采集方式,通过对风力发电机组的转速、振动频率、温度、湿度等参数进行实时监测,将模拟信号转化为数字信号后传送给PC机,以便保证安全运行和在线故障监测,从而确保对风力发电机组的运行情况进行实时掌控。     

浅析水轮发电机调速器的维护及故障排除

水轮发电机组是水电厂进行电能生产的重要设备,是水能发电的核心,而调速器是调节水轮发电机组中调节机组的核心器件,担负着发电机组输出功率和输出频率调节的重任,只有确保调速器的正常运行,才能确保发电机组电能的正常输出。然而在水电站的生产过程中水轮发电机的调速器难免会发生故障,严重威胁着水电站的正常生产。因此本文结合以往经验,对水轮机组调速器的维护和故障排除进行了论述。     

柴油发电站远端监控系统研究

柴油发电站主要是以柴油发电机组为动力的工频交流同步发电机,其具有热效率高、燃油储存容易、结构紧凑、启动快以及占地小等特点。但是在柴油发电机组在运行的过程中也会出现故障,严重影响设备的正常供电,对系统以及柴油发电站造成的严重的损失。所以为了保证柴油发电机组运行的安全性和可靠性,在柴油发电站中设置远端监控系统不仅能够迅速发现柴油发电站存在的故障隐患,而且还能够使机组操作人员能够及时采取紧急措施,有效避免柴油发电机组的损坏。     

Nonlinear function generators and chaotic signal generators using apulse-width modulation method

A new approach for making arbitrary nonlinear transfer function generator circuits is proposed. Arbitrary non-monotone functions can be made by combining plural pulse-width modulation (PWM) circuits. Chaotic signal generators can be made by using these circuits. This approach is useful for implementing large-scale nonlinear circuit systems     

基于VSG的并网逆变器功率控制研究

虚拟同步发电机控制技术能够让并网逆变器自主稳定地参与电网运行。为验证虚拟同步发电机控制的作用并解决电磁功率收敛扰动较大的问题,文中分析了虚拟同步发电机的数学模型和控制策略,并基于同步旋转坐标的方法,提出一种优化的虚拟同步发电机控制。搭建 15 kVA的虚拟同步发电机仿真系统,并通过处理器在环实验验证。结果表明,所设计的控制策略不仅具有较好的功率跟踪和调频调压性能,还能为系统提供惯性和阻尼。同时,新的控制策略减少了电磁功率收敛扰动,提高了系统的稳定性和灵活性。     

Energy harvesting with pairs of variable capacitors without control circuits

This work describes several electronic electrostatic generators that can be built using two pairs of complementary variable capacitors, in a way that dispenses control circuits for their operation. In all cases, a basic unstable generator based on an electrostatic charge multiplier is used to bias variable capacitors, and the current generated by these capacitors is then rectified and sent to the load. Experimental versions of the proposed generators were built using variable capacitors made with 3D-printing techniques, moved in a back-and-forth way by a small motor. As these generators operate at high impedance level, always with small currents, they are insensitive to the resistivity of the conductive plastic used to make the variable capacitors. Several new structures are presented, and their properties are evaluated theoretically and experimentally.     

通信用柴油发电机组的功率

简要介绍了柴油发电机组的功率组成、各部分功率的意义和相互关系、以及几种不同的功率定额，并结合通信行业的使用特点，对机组的使用以及选型中涉及到一些具体问题作了详细的分析和探讨。     

AC strength of a pattern generator

The AC strength of a pattern generator is the fraction of the exhaustive two-pattern count that it can apply to the logic given sufficient time. It is a measure that allows assessing how well a pattern generator can serve in applying AC test vectors to the logic. Generators with high AC strengths tend to perform better than generators with low AC strengths.Special generators with high AC strengths can be designed with a considerable penalty of hardware overhead. An alternative to designing special pattern generators that can serve well during AC test is to separate the inputs of the logic fed by the generator, so that no two inputs belonging to the same output cone in the logic are connected to adjacent stages of the generator. This input separation will facilitate an effective AC test, and will not suffer from the high overhead that the special generators suffer from.This paper introduces the notion of the AC strength of a pattern generator and proposes the input separation scheme that will allow an efficient AC test to be performed on the logic.     

A New Approach to Analysis and Design of Chaos-Based Random Number Generators Using Algorithmic Converter

This paper presents a new approach to analysis and design of ADC-based random number generators. To this end, different full-bit and half-bit redundant stages of algorithmic converter are used to design chaotic maps. It is shown that, in the redundant and nonredundant structures, output probability density function of the converter stages and their related chaotic functions always converge to uniformity. It is demonstrated that residues become independent and uniformly distributed. This fact leads to the randomness and uniformity of distribution of the random number generator output bits. Moreover, it is shown that some common chaotic maps that are employed in chaotic random number generators can be implemented using nonredundant and half-bit redundant stages of algorithmic converter. In this way, the capability of ADC-based generators in designing chaotic maps and producing random number sequences is illustrated. The validity of the proposed chaos-based random number generator is confirmed using NIST statistical tests even in the presence of nonidealities in algorithmic converter. Since the ADCs are mixed-signal integrated circuits and can be used in high-speed applications, the ADC-based random number generator has high throughput and is easily embeddable in all analog and digital circuits.     

PTN技术在全球运营网中的典型应用案例分析

目前,分组传送网(PTN)技术在全球已经大规模地部署和建设,针对PTN这一全新技术和设备,在开始的规模部署期内,必然会面临许多新问题和新挑战,本文深入分析了PTN技术在全球运营网中的典型应用和部署方案,并分析了方案的优势和劣势,为国内各电信运营商部署PTN技术提供参考。     

A 500‐kW PV generator I–V curve

This paper presents the measurement of the I–V curve of a 500‐kW PV generator by means of an own‐made capacitive load. It is shown that I–V curve analysis can also be applied to big PV generators and that when measuring the operation conditions with reference modules and taking some precautions (especially regarding the operation cell temperature), it is still a useful tool for characterizing them and therefore can be incorporated into maintenance procedures. As far as we know, this is the largest I–V curve measured so far. Copyright © 2013 John Wiley & Sons, Ltd.     

The construction method of stabilizer codes for continuous variables

The paper analyzes the basic principles of stabilizer codes, focusing on how to construct stabilizer codes for achieving the continuous-variable quantum error correction. Stabilizer codes can be used in the reconciliation of continuous-variable quantum key distribution system. The construction method of stabilizer codes is very important and it can be turned into finding the check matrix for stabilizer codes. In this paper, a new algorithm called region elimination algorithm for finding the check matrix of stabilizer codes was presented which can seek the voluntary check matrix for continuous-variable stabilizer codes within 8 bit code length quickly and effectively, and it was simulated by Visual C++. The algorithm is mainly realized by initializing search region, reducing the search region and then keeping searching till finding all the commuting generators. The finding of check matrix of stabilizer codes lays important foundations for the further development of stabilizer codes in the continuous-variable quantum key distribution.     

基于DSP的信号发生器的设计与实现

阐述了基于TMS320VC5402 DSP实现信号发生器的设计原理和实现方法，详细介绍了所设计的信号发生器的硬件电路结构和程序设计流程图。该信号发生器可以产生任意复杂的波形，且信号的幅度和频率全部由DSP程序控制，易于修改，弥补了通常信号发生器模式固定、波形不可编程以及精度低的不足。此外，还运用了DSP的外部并行16位FLASH引导装载设计方法，通过在线FLASH编程，使得所设计的DSP目标系统成为一个独立的脱机运行系统，灵活性大大增强，使用也更加方便。