| Transmission and distribution lines are essential parts of the power systems, attaching power plants and end-users. Meanwhile power lines are the places where the most faults occur in power system, and the fault seeking is very difficult because these lines are mostly working in harsh circumstance, exposing to the wind and rain and passing through hill and field. When power line faults occur, quickly removing the fault and correctly locating the fault point would be critical for repairing power lines and restoring power supply in time. Moreover, it would also play an important role in safety stability and economical operation of the whole power systems.In recent years, with the development of data gathering and processing, and optical electric transducer operative technology, traveling wave based ultra high speed protection and fault location are currently highlighted in relay protection domain, and some have been applied in power systems and obtained certain achievements. But by now, these technologies still have not been put into application well enough; and there are still some questions needed to be researched further.According to the current questions and utilizing the predecessor's work andintegrating modern analysis method and technique, this paper studies ontransient traveling wave based ultra high speed protection and fault location, putforward new principles and algorithms, and look forward to solving theproblems of current technology. Details of the research works are as following:Establish the transmission line model which consider frequencycharacteristic, adopt phase to mode transformation, and analyze thechanging rule with frequency of the resistance, inductance, wave velocity,and attenuation coefficient of each modes. Further analyze the advantage ofusing dyadic wavelet transform to detect singularity, and point out theadvantages and disadvantages of exploiting WTMM and WTMS methods inLipschitz exponent calculating. Propose a new Lipschitz exponent estimatedalgorithms based on the least square method with a high precision, whichprepared the ground for the quantitative analysis of Lipschitz exponent.This paper obtains the following conclusions through analyzing transienttraveling wave changing rule with propagation distance: wave velocitydetected decreases monotonously with propagation distance increasing;wave head Lipschitz exponent increases monotonously with propagationdistance increasing. Obtain the special correspondence of wave velocity towave head Lipschitz exponent, analyze transition resistor, fault inceptionphase, fault type influences on wave velocity and wave head Lipschitzexponent, and gain the conclusion that it does not affect the correspondsbasically.This paper verifies the changing rule of the wave velocity and wave head Lipschitz exponent with propagation distance, using transmission line parameter. And this paper presents the fact that transition resistor and inception angle influence on wave velocity and wave head Lipschitz exponent by simulation. The simulation results have verified the effectiveness of the principle analysis. From the analysis above, this paper presents new fault location algorithm based on zero mode and aerial mode traveling wave, using wavelet transform and BP neural network technology. The effectiveness of the algorithm has been verified by the ATP simulation results.This paper verifies the above conclusions again using distribution line parameter, and put forward a new estimation method of zero mode wave velocity based on splint interpolation. Thus a new fault location algorithm based on zero mode and aerial mode traveling wave has been presented. And ATP simulation results have verified the fault location precision. Since the distribution length is short, there is little influence of transition resistor and inception angle on wave velocity, so it can be considered that the propagation distance is only relate to the propagation time gap of zero mode and aerial mode. This paper model the relation between propagation distance and the propagation time gap using BP neural network, and bring forward a new fault location based on zero mode and aerial mode traveling wave. The effectiveness of the algorithm has been verified by the ATP simulation results. Based on above analysis, a new algorithm of fault location based on wavelet transform and neutral network is presented, which take advantages of the time-frequency analysis capacity of wavelet and neural network strongly nonlinear fitting capacity. The effectiveness of the criterion has been verified by the ATP simulation results.Presents a single end traveling wave protection algorithm. This paper draws the following conclusion analyzed the influence of line trap on transient traveling wave: aerial mode velocity changes little in front and rear of line trap; zero mode velocity has a sudden change in front and rear of line trap, so that the propagation time gap of zero mode and aerial mode has a sudden change in front and rear of line trap, and the fault zone can be determined based on this conclusion. This paper also analyzes traveling wave energy direction unit principle, and adds latch condition in forward and reverse fault. Thus the boundary unit and direction unit can form the whole line quick protection. In the end, the effectiveness of presented algorithm has been verified by the ATP simulation results.Put forward a new fault line selection criterion in non-solidly earthed network based on direction traveling wave. Using the traveling wave technology, this paper elaborately analyzes the transient state process of non-solidly earthed network when single phase earth fault occurring, and discovered the follow conclusions: in the fault line forward voltage traveling wave and the backward voltage traveling wave are both arrived, but in the healthy lines, the arrival time of the backward voltage traveling wave lagged behind that of the forward voltage traveling wave certain amount; the initial polarity of forward voltage traveling wave in the fault line and the health line is extremely opposite. According to those two characteristics, this paper proposes new criterion of fault line selection based on the ratio of the forward and backward traveling wave energy and the forward voltage traveling wave polarity. This criterion will not be affected by fault initial phase angle and transition resistance. The effectiveness of the criterion has been verified by the ATP simulation results.A new criterion for fault line selection based on the maximum of zero-sequence transient current is proposed. It utilizes the approximate coefficients and its relative time domain information after wavelet transform. The characteristic time and characteristic value of zero-sequence voltage are defined. At the characteristic time, the zero-sequence current polarity of faulted feeder is opposite from the healthy feeders. However, if all the polarities are the same, the fault occurs on the bus bar. For the system with only two feeders, this method can compare the polarity of the maximum of zero-sequence transient current and characteristic value of zero-sequence voltage. The db4 wavelet is selected to analyze the original signal in 4 levels. Not affected by fault initial phase angle and the manner of neutral grounding, this criterion is capable of withstanding high transition resistance. The effectiveness of the criterion has been verified by simulation.fault line selection device for non-solidly earthed network is designed and developed. For overcoming the low success rate of the fault line selection and the low level of automation of single-phase earth fault diagnosis in non-solidly earthed network, this paper proposes a synthetic fault line selection based on three criterions: injection signal method, the criterion based on the increment of active component of zero sequence current, and the criterion based on the maximum of zero sequence transient current. About the hardware of the device, this paper designed a system based on double CPU, which formed by uPSD3334D with powerful system functions and rich peripheral ports and TMS320VC33 with powerful data processing ability. Also this paper provides a hardware platform to have friendly interface and network capacity. The devices have been applied in relay protection training system of Tai'an electric school with good performance, and have been tested in Zhongshisanlian substation of Daqing Oilfield. During these tests all the fault lines have been selected correctly.
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