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1.发明授权Generator protection system and method of compensating for errors in phasor estimation due to oscillations in discrete Fourier transform 失效发电机保护系统和补偿由于离散傅立叶变换振荡引起的相量估计误差的方法
公开(公告)号：US5832414A
公开(公告)日：1998-11-03
申请号：US939932
申请日：1997-09-29
申请人： David G. Hart , James D. Stoupis , Damir Novosel
发明人： David G. Hart , James D. Stoupis , Damir Novosel
CPC分类号： G01R19/2513 , G01R23/16 , G01R23/00
摘要： A new method of compensating for errors in phasor estimation due to oscillations caused by discrete fourier transforms used to estimate signal frequency is provided. The method uses a variable N-point DFT to compute one or more phasors based on data acquired from one or more sampled signals. At each sampling interval the change in phasor angle between the current sampling interval and the previous sampling interval is determined and used to estimate the instantaneous frequency of the signal. A non-oscillating phasor indicative of the instantaneous magnitude, angular frequency, and phase angle of the signal is generated based on the instantaneous frequency estimate. Instantaneous frequencies are averaged over a cycle of the signal to generate an average cycle frequency. In addition, a number of discrete frequencies and corresponding DFT windows based on a fixed sampling rate and a predetermined fundamental frequency of the signal are defined and used in estimating the instantaneous frequency. The DFT window is adjusted by setting it equal to the DFT window corresponding to the discrete frequency closest to the average cycle frequency. A generator protection system analyzing voltage and current signals output from a generator is also provided. The voltage and current signals are monitored by respective voltage and current sensors to produce a plurality of signals representative of voltage and current characteristics of the generator. The system comprises components for receiving and sampling signal input, and for processing the samples according to the inventive method.
摘要翻译： 提供了一种补偿由于用于估计信号频率的离散傅立叶变换引起的振荡引起的相量估计误差的新方法。 该方法使用可变N点DFT来基于从一个或多个采样信号获取的数据来计算一个或多个相量。 在每个采样间隔，确定当前采样间隔和先前采样间隔之间的相量角的变化，并用于估计信号的瞬时频率。 基于瞬时频率估计产生指示信号的瞬时幅度，角频率和相位角的非振荡相量。 瞬时频率在信号的周期上平均以产生平均周期频率。 另外，基于固定采样率和信号的预定基频定义了多个离散频率和相应的DFT窗口，并用于估计瞬时频率。 通过将DFT窗口设置为与最接近平均周期频率的离散频率对应的DFT窗口进行调整。 还提供了分析从发电机输出的电压和电流信号的发电机保护系统。 电压和电流信号由相应的电压和电流传感器监测，以产生代表发电机的电压和电流特性的多个信号。 该系统包括用于接收和采样信号输入的组件，并且用于根据本发明的方法处理样本。
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公开(公告)号：US06185482B2
公开(公告)日：2001-02-06
申请号：US09037359
申请日：1998-03-10
申请人： Michael Egolf , David G. Hart , James D. Stoupis
发明人： Michael Egolf , David G. Hart , James D. Stoupis
IPC分类号： H02J114
摘要： A method and apparatus for over current backup protection is provided. The method generates a set of root mean square (rms) values from samples that are taken from the system current. Several rms current values are averaged to generate an estimated rms over current value. The estimated over current value is compared with a predetermined threshold value. If the estimated current is above the predetermined threshold value, a fault protection mechanism, such as opening a circuit breaker, is activated. A generator protection unit having digital signal processing capabilities executes the inventive method to provide protection from over current episodes.
摘要翻译： 提供了一种用于过流备份保护的方法和装置。 该方法从从系统电流获取的样本中生成一组均方根（rms）值。 将几个均方根电流值平均以产生超过电流值的估计有效值。 将估计的过电流值与预定阈值进行比较。 如果估计电流高于预定阈值，则启动诸如断路器之类的故障保护机构。 具有数字信号处理能力的发生器保护单元执行本发明的方法以提供对过去电流的保护。
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公开(公告)号：US06738719B2
公开(公告)日：2004-05-18
申请号：US09951925
申请日：2001-09-13
申请人： James D. Stoupis , David Lubkeman , Reto Buettner , David G. Hart
发明人： James D. Stoupis , David Lubkeman , Reto Buettner , David G. Hart
IPC分类号： G01R3100
摘要： The invention describes a method, system, device, and computer-readable medium having computer-executable instructions for classifying faults on an electrical power line. In particular, the invention permits the classification of crossover faults, using a local measurement technique. The inventive method includes providing a first electrical power transmission line and a second electrical power transmission line, and monitoring the first electrical power transmission line to identify a crossover fault occurring between the first and the second electrical power transmission lines.
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公开(公告)号：US6081768A
公开(公告)日：2000-06-27
申请号：US929927
申请日：1997-09-15
申请人： Yi Hu , David G. Hart , Joseph P. Benco , James D. Stoupis
发明人： Yi Hu , David G. Hart , Joseph P. Benco , James D. Stoupis
摘要： A method and system for detecting the peak of respective half-cycles of a sinusoidal waveform. The sinusoidal waveform is rectified and only sample points above a first threshold are analyzed. The peaks of each half-cycle are only accepted if they are above a second, greater threshold. Peaks below the second threshold are not accepted. The peaks themselves are detected by starting a counter at the first sample in the rectified waveform which is above the first threshold value. Once the rectified waveform descends below the first threshold, the counter is stopped and the maximum value of the previous k samples is the peak value, where k is the counter value for the successive samples above the first threshold. The peak value so determined is rejected if it is less than the second threshold value. On the other hand, when the peak value is above the second threshold, it is averaged with the last valid peak value (above the second threshold). Thus, the V/Hz value remains the same until a new, valid peak is determined. A preferred embodiment implements such a digital peak detector in a digital relay system for detecting overexcitation of a power system.
摘要翻译： 用于检测正弦波形的各个半周期的峰值的方法和系统。 正弦波形被整流，并且仅分析高于第一阈值的采样点。 每个半周期的峰值只有在高于第二个较大的阈值时才被接受。 低于第二个阈值的峰值不被接受。 通过在高于第一阈值的整流波形中的第一采样处启动计数器来检测峰值本身。 一旦整流波形下降到第一阈值以下，则停止计数器，并且先前k个采样的最大值是峰值，其中k是高于第一阈值的连续采样的计数器值。 如果确定的峰值小于第二阈值，则其被拒绝。 另一方面，当峰值高于第二阈值时，用最后的有效峰值（高于第二阈值）进行平均。 因此，在确定新的有效峰值之前，V / Hz值保持不变。 优选实施例在数字中继系统中实现这种数字峰值检测器，用于检测电力系统的过激励。
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公开(公告)号：US06760670B2
公开(公告)日：2004-07-06
申请号：US09951689
申请日：2001-09-13
申请人： James D. Stoupis , David Lubkeman , Reto Buettner , David G. Hart
发明人： James D. Stoupis , David Lubkeman , Reto Buettner , David G. Hart
IPC分类号： G01R3100
摘要： The invention describes a method, system, device, and computer-readable medium having computer-executable instructions for classifying faults on an electrical power line. In particular, the invention permits the classification of crossover faults using a local measurement technique. The inventive method includes providing a first electrical power transmission line and a second electrical power transmission line, and monitoring the first electrical power transmission line to identify a crossover fault occurring between the first and the second electrical power transmission lines.
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公开(公告)号：US06741943B2
公开(公告)日：2004-05-25
申请号：US09951495
申请日：2001-09-13
申请人： James D. Stoupis , David Lubkeman , Reto Buettner , David G. Hart
发明人： James D. Stoupis , David Lubkeman , Reto Buettner , David G. Hart
IPC分类号： G01R3100
摘要： The invention describes a method, system, device, and computer-readable medium having computer-executable instructions for classifying faults on an electrical power line. In particular, the invention permits the classification of crossover faults, using a local measurement technique. The inventive method includes providing a first electrical power transmission line and a second electrical power transmission line, and monitoring the first electrical power transmission line to identify a crossover fault occurring between the first and the second electrical power transmission lines.
摘要翻译： 本发明描述了具有用于对电力线上的故障进行分类的计算机可执行指令的方法，系统，设备和计算机可读介质。 特别地，本发明允许使用局部测量技术对交叉故障进行分类。 本发明的方法包括提供第一电力传输线和第二电力传输线，并且监视第一电力传输线以识别出现在第一和第二电力传输线之间的交叉故障。
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公开(公告)号：US06721670B2
公开(公告)日：2004-04-13
申请号：US09951267
申请日：2001-09-13
申请人： James D. Stoupis , David Lubkeman , Reto Buettner , David G. Hart
发明人： James D. Stoupis , David Lubkeman , Reto Buettner , David G. Hart
IPC分类号： G06F1300
摘要： The invention describes a method, system, device, and computer-readable medium having computer-executable instructions for classifying faults on an electrical power line. In particular, the invention permits the classification of crossover faults using a local measurement technique. The inventive method includes providing a first electrical power transmission line and a second electrical power transmission line, and monitoring the first electrical power transmission line to identify a crossover fault occurring between the first and the second electrical power transmission lines.
摘要翻译： 本发明描述了具有用于对电力线上的故障进行分类的计算机可执行指令的方法，系统，设备和计算机可读介质。 特别地，本发明允许使用局部测量技术对交叉故障进行分类。 本发明的方法包括提供第一电力传输线和第二电力传输线，并且监视第一电力传输线以识别出现在第一和第二电力传输线之间的交叉故障。
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8.发明授权Generator protection system and method for phasor estimation and frequency tracking during frequency ramping 失效发电机保护系统和频率估计和频率跟踪频率跟踪方法
公开(公告)号：US5832413A
公开(公告)日：1998-11-03
申请号：US939514
申请日：1997-09-29
CPC分类号： G01R19/2513 , G01R23/16 , G01R23/00
摘要： A method for estimating phasors and tracking the frequency of a signal during frequency ramping is provided. The method uses a variable N-point DFT periodically to compute one or more phasors based on data acquired from one or more sampled signals. The period between DFT computations is a predetermined number of sample periods. After each DFT computation, the change in phasor angle between the current phasor estimate and the most previous phasor estimate is determined and used to estimate the instantaneous frequency of the signal. The current instantaneous frequency estimate and the most previous instantaneous frequency estimate are averaged to compute an average cycle frequency. In addition, a number of discrete frequencies and corresponding DFT windows based on a fixed sampling rate and a predetermined fundamental frequency of the signal are defined and used in estimating the instantaneous frequency. Once the average cycle frequency is determined the DFT window is adjusted by setting it equal to the DFT window corresponding to the discrete frequency closest to the average cycle frequency. A generator protection system analyzing voltage and current signals output from a generator is also provided. The voltage and current signals are monitored by respective voltage and current sensors to produce a plurality of signals representative of voltage and current characteristics of the generator. The system comprises components for receiving and sampling signal input, and for processing the samples according to the inventive method.
摘要翻译： 提供了一种用于在频率斜坡期间估计相量并跟踪信号频率的方法。 该方法使用可变N点DFT周期性地基于从一个或多个采样信号获取的数据来计算一个或多个相量。 DFT计算之间的周期是预定数量的采样周期。 在每个DFT计算之后，确定当前相量估计与最先前相量估计之间的相量角的变化，并用于估计信号的瞬时频率。 对当前瞬时频率估计和最先前的瞬时频率估计进行平均以计算平均周期频率。 另外，基于固定采样率和信号的预定基频定义了多个离散频率和相应的DFT窗口，并用于估计瞬时频率。 一旦确定平均周期频率，则通过将DFT窗口设置为等于最接近平均周期频率的离散频率的DFT窗口来调整DFT窗口。 还提供了分析从发电机输出的电压和电流信号的发电机保护系统。 电压和电流信号由相应的电压和电流传感器监测，以产生代表发电机的电压和电流特性的多个信号。 该系统包括用于接收和采样信号输入的组件，并且用于根据本发明的方法处理样本。
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公开(公告)号：US07154722B1
公开(公告)日：2006-12-26
申请号：US09946232
申请日：2001-09-05
CPC分类号： H02H3/06 , H02H7/26 , Y10T307/313 , Y10T307/391
摘要： The invention contemplates a technique for providing loop control on a faulted overhead or underground loop system, while preventing restored current from being fed or back fed into the fault. In particular, the invention provides a method, device, and system for restoring power to a faulted loop distribution system. The inventive method includes detecting a fault on the loop distribution system, interrupting current on the faulted part of the loop distribution system, isolating the faulted part of the loop distribution system from an unfaulted part of the loop distribution system, restoring current to the unfaulted part of the loop distribution system, and preventing the current from flowing to the faulted part of the loop distribution system. The method may further include providing the current to a load.
摘要翻译： 本发明考虑了一种用于在故障的开销或地下回路系统上提供回路控制的技术，同时防止恢复的电流被馈送或反馈给故障。 特别地，本发明提供了一种用于恢复故障回路分配系统的功率的方法，装置和系统。 本发明的方法包括检测环路分配系统上的故障，中断环路分配系统故障部分的电流，将环路分配系统的故障部分与环路分配系统的未故障部分隔离，将电流恢复到未故障部分 的环路分配系统，并防止电流流向环路分配系统的故障部分。 该方法还可以包括向负载提供电流。
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公开(公告)号：US07110231B1
公开(公告)日：2006-09-19
申请号：US10232627
申请日：2002-08-30
摘要： A preferred embodiment of a system comprises a recloser electrically coupled to a voltage source of a power-distribution network and adapted to isolate a section of a distribution feeder of the power-distribution network from the voltage source in response to an overcurrent condition in the section of the distribution feeder. The system also comprises a sectionalizer electrically coupled to the section of the distribution feeder. The sectionalizer and the recloser are adapted to communicate via a data network and the recloser is responsive to control inputs sent to the recloser from the sectionalizer over the data network.
摘要翻译： 系统的优选实施例包括电耦合到配电网络的电压源的重合器，其适于将配电网络的配电馈线的一部分与电压源隔离，以响应于该部分中的过电流状况 的配送馈线。 该系统还包括电耦合到分配馈线的部分的分段器。 分段器和重合器适于经由数据网络进行通信，重合器响应于通过数据网络从分段器发送到重合器的控制输入。
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