基于80C196KC微处理机的同步电机智能化转速继电器

分析了同步电机转速信号装置的发展现状,介绍了智能化转速继电器的工作原理,软硬件结构以及抗干扰措施.现场应用实践表明,该转速继电器具有测速精度高,测速范围宽,操作简单,可靠性高,与上位机通信方便等优点,具有推广应用价值.     

永磁发电机现场简易充去磁

永磁发电机现场简易充去磁桓仁发电厂舒世承１引言水轮发电机组，大部分采用同轴式永磁发电机。永磁发电机所带的负荷包括水轮发电机组机械调速装置的测量元件飞摆电动机、及水轮发电机组制动保护用的测速继电器。转速继电器１１５％ｎ＿ｅ接点作用于机组过速停机，转速继...     

磁阻脉冲数字和模拟测速装置在十万千瓦汽轮机上的应用

为了提高转速测量的准确性和可靠性,我厂在十万千瓦汽轮机上采用磁阻脉冲测速技术,代替原配套测速发电机型的测速装置。现可用数字及模拟仪表共同监视汽轮机转速。实现汽轮机从42转/分开始测量转速。由于模拟仪表具有动作灵敏,加上数字显示,对汽轮机升速,超速试验和安全运行创造了有利的条件。     

基于CPLD的电机数字测速及显示

本文介绍了电机的测速及显示原理.主要论述了一种不同于常用测速及显示技术的方法,它采用全数字电子计数测频法测速、使用4位7段数码管显示转速,具有编程实现容易、单片实现测速和显示等特点.     

带有转子位置检测器类电动机的几种测速方法的研究

带有转子位置检测器类电动机的测速除了常用的测速方法外，还有其特有的测速方法。本文分析讨论了几种测速方法的特点和应用，在构成这类电动机的转速闭环时，根据不同指标要求和应用场合选择合适的测速方法具有实际意义。     

上期想想看答案

1.为什么有时称测速发电机为速度反馈元件、阻尼元件或角加速度信号元件？测速发电机用于测速仅是它的一个功能。实际上,测速发电机在运动控制系统中有更多用途。在速度闭环控制系统中,可将测速发电机用作转速反馈。这时便称测速发电机为速度反馈元件。对运动系统来说,测速发电机的负载电流具有阻尼作用。测速发电机转速越高,测速电压就越高,负载电流随之越大,其阻尼作用也越大,可抑制系统振荡。因此,当测速发电机在运动控制系统中主要起阻尼作用时,便称它为阻尼元件。     

带光电编码器的电机车调速控制系统研究

介绍了现有电机车转速检测方法的原理和特点,推导了相应的转速计算公式.针对改进型转差频率控制系统,分析了测速误差和机械误差的影响,并在调速精度和启动时间两方面与矢量控制系统进行了对比.仿真结果表明,该系统具有更大的测速误差容许度和更好的稳定性,在保证调速精度的同时具有更快的启动时间.提出了一种利用dsPIC30F数字信号处理器进行转速控制的实现方案,该方案简单可靠,且转矩稳定,转速变化平稳,已经成功应用于工矿电机车中.     

基于卡尔曼滤波的超声波电动机测速算法研究

使用增量式编码器的超声波电动机伺服系统利用M测速算法时存在较大的误差,针对这一情况,提出一种卡尔曼滤波测速算法。该方法在不改变原有电路的情况下,针对性地设计了状态方程和观测模型。仿真结果与实测的M测速算法结果相比较,卡尔曼滤波能够很好地跟随电机转速的变化,同时有效地抑制噪声对于测速的影响,降低了转速的超调量。并且根据仿真结果提出了一种改进的卡尔曼滤波,简化了计算量,使其具有较强的实用性。     

同步电动机转速测量的改进

同步电动机的转速,理论上是与旋转磁场的转速严格同步的,即电动机的转速仅取决于电源频率,通常不需对同步电动机进行转速测量,但为了监视电动机在负载状态是否失去同步,仍需使用测速装置。原则上,一般电动机的转速测量装置均适用于同步电动机,例如机械式转速表,测速发电机,闪光测速     

电动机测速及显示分析

通过对单片机复位电路的原理,利用传感器对电动机转速进行测速,发电机的电压高低反映了转速的高低。为了能精确地测量转速外,还要保证测量的实时性,要求能测得瞬时转速方法,证明了转速的测试具有重要的意义。     

Research on Improving the Power Monitor Function

1. ForewordThe distributed line monitoring apparatus are more and morewidely used in the distribuhon network now. Since most ofthem have not any funchon of the relay protechon or somehairs the poor performance on the protechon, they could notsahsfiy the requirement ot the comprehensive automation indistribuhon netWork. It wb occur that the resources gO towaste and the protocols of communicahon betWeen two sets ofequipment is not in agreement When an addihonal computerrelay protechon is equiP…     

温度继电器温度特性自动检测系统的研究

研究设计了基于空气测定法原理,简单实用、高精度的温度继电器温度特性自动检测系统。该检测系统,是用电阻加热炉模拟温度继电器周围的环境温度,通过控制加热炉内温度的变化,从而测得温度继电器的动作温度。系统按设定的控温曲线对温场温度进行控制,并采用模糊算法,采取最小二乘法误差校准,将电阻加热炉炉丝按功率进行分组,并在试验腔的检测段放置孔板,使测试区域的温度均匀,有效提高了系统检测精度。经测试该系统测试精度满足要求,具有良好的使用效果。     

The Principle and Practice of the Deviation of Power Frequency Component Relay on High Voltage Transmission Line

Theprinciplesofpowersystemprotectiverelayinghasgotrapidprogressinrecenttwentyyears.AmongthemtheultrahighspeedprotectiverelaywhichaffectsmosttheeIectricpowersystemhasgotpracticalapplication.ThefirstuItrahighspeedprotectiverelayLljbasedonthetravellingwavetheorywasdeveIopedinl975.Itgaverisetogreatinterestoftheprotectiverelayengineers.Sincethenseveralmodificationsofthetravellingwaverelaywereproposedandsomeofthemwereputintoapplicationinthepowersystem.Buttheserelaysencounteredgreatcontradictorybet…     

基于STM32F103R8T6的数字式量度继电器设计与应用

数字式量度继电器具有测量精确、设定简单、保护功能多、速度快等优点,是传统的电磁、静态继电器理想的替代产品。详细介绍了基于STM32F103R8T6的数字式量度继电器的总体设计方案。该产品能针对不同的对象在实际使用中遇到的多种故障进行保护,使被保护的对象在故障状态下不会产生损坏,提高可靠性,减少损失。     

The Development and Application of Directional Comparison Protection for Series Compensated Transmission Systems

A new high speed Directional Comparison protection relay for capacitor compensated lines is described. It is shown that the special filtering and signal processing techniques developed overcome many difficult protection problems encountered on such lines. The relay design has been performed using computer-aided design (CAD) techniques and recent work on its implementation using a 16-bit bipolar microcomputer has been initiated. The latter indicates that the relay is readily implemented using present generation hardware.     

基于超程时间测量的电磁继电器故障检测

针对现有电磁继电器隐性故障检测率较低的问题,提出一种基于超程时间测量的电磁继电器故障检测方法。首先,通过离线优化获取最优模糊阈值,然后应用线性回归方法,对超程时间监测数据进行在线预测,并利用拟合误差将预测值扩展为预测区间;其次,根据最优模糊阈值,将监测数据和预测区间分别转换为当前和预测故障证据,利用区间证据推理迭代融合积累、当前、预测3种故障证据,获取更新后的积累故障证据;最后,按照故障判据,由积累故障证据得到继电器故障检测结果。所提方法充分考虑了继电器隐性故障的渐变性特征以及超程时间测量过程所包含的不确定性,使故障证据更贴近于继电器实际工况。实验结果表明,与现有方法相比,所提方法在证据准确性和收敛速度上具有显著优势,能够有效提升电磁继电器隐性故障的检测精度。     

A novel fast distance relay for long transmission lines

The measuring accuracy and the measurement stability of conventional distance relay will be influenced by complex and remarkable harmonic components due to the large capacitance of the line when it is used for a long line. Correspondingly, the tripping speed will be delayed to some extent. To solve this problem, a fast distance relay for long transmission lines is presented, which is on the basis of the differential equation algorithm using π transmission line model and the theory of Equal Transfer Process of Transmission Lines (ETPTL). The shortcomings of π model differential equation algorithm due to the impact of high frequency components can be overcome by using a low-pass filter. The problem resulting from the difference between the transfer feature of the voltages used by the distance protection and that of the currents due to the transient characteristic of coupling capacitor voltage transformers (CCVT) can be solved by using virtual digital CCVT. Then, the new distance relay can trip quickly by re-structuring the voltage at the fault point and iterative calculations. A variety of ATP simulation tests show that the new relay has fast tripping speed and high reliability when applied to the long transmission lines.     

A new PMU based power swing detector to prevent mal-operation of distance relay

In conventional transmission line protection, a distance relay is used to provide the primary as well as remote backup protection. The voltage and current phasors measurement needed by the distance relay for determining the impedance may be affected by the power disturbances such as power swing. Consequently, this power swing may cause mal-operation of Zone three distance relays which in turn may affect on the reliability of the whole protective scheme. To mitigate these effects and hence improve the relay reliability, this work proposes a new real-time power swing detector using phasor measurement units for blinding the distance relay only during this transient disturbance. However, this developed detector will not block relay when the power swing accompanied with faults. To validate the present work, the performance of developed enhanced distance relay is tested by signals generated by Simulink/MATLAB simulator under different conditions. The test results show that this proposed scheme provides good discrimination between the transient currents and the fault current which in turn it may contribute in enhancing the reliability of Distance relay.     

基于噪声估计的自适应快速距离保护

继电保护滤波算法的速度和滤波能力间的固有矛盾阻碍了传统继电保护动作速度的进一步提高.提出了一种基于噪声估计的自适应快速距离保护,通过实时检测故障信号的噪声水平来估计滤波算法的误差,并根据误差大小自动调整距离保护的动作门槛,以此获得最佳的动作速度.该保护已在某数字式高压线路保护装置中获得应用.该装置的动模试验结果表明,所提出的自适应快速距离保护可以有效地防止区外故障时的超越,同时在区内故障时具有很快的动作速度.     

A Distance Protection Relay for a 1000-kV UHV Transmission Line

A traditional distance protection relay uses a lumped parameter model of the transmission line. For a long 1000-kV UHV line with large distributed capacitance, such a simplified line model is inadequate and can cause malfunction of the relay due to large errors in the impedance measurement. This paper presents a new line model for a distance relay and the procedure of reliable fault impedance measurement and relay setting. It describes the proposed application of the relay developed to a 645-km 1000-kV UHV transmission line including shunt reactor compensation, which is currently being constructed in China. Tests are carried out on an RTDS (real time dynamic system) to evaluate the relay performance, showing significant improvement compared to a more traditional distance relay. The new distance relay is shown to satisfy the requirement of 1000-kV UHV transmission line protection.