System background:
Technical principles:
The high frequency signal produced when the line fault occurs, reaches the GPS synchronization time of the substation at both ends of the line. The location of the fault point can be calculated. The high frequency signal speed of the line fault is close to the speed of light at v. Therefore, positioning accuracy is only related to time measurement, with small positioning error and high reliability.
Application status:
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WGXD-2007 products |
Impedance product |
Wavelet algorithm product |
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principle |
Analyze and calculate the time of fault traveling wave arriving at both ends of fault line to locate fault. |
Calculation of fault location by calculating the impedance of a fault line |
Analysis and calculation of current waveforms of fault lines for fault location |
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function |
Metal grounding fault and high resistance grounding fault location |
High resistance grounding fault can not be located |
Difficult location of high resistance grounding fault |
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accuracy |
Fault location error is less than 150m |
Fault location error is large |
Fault location error is less than 500m |
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Installation requirements |
A special signal sensor is used to induce line fault signals. The sensor is designed for core piercing, installed on the grounding prop of CVT/PT, and does not affect the operation of other equipment. |
The relay protection equipment and recording equipment in the substation have this function. |
On the two side of CT, the current waveform is extracted, and there are hidden troubles affecting the operation of the two equipment. |
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Monitoring range |
The installation of a set of equipment in substations can have the ability to monitor different voltage levels, and is suitable for conventional substations, digital substations and GIS substations. |
Auxiliary functions of relay protection equipment and recording equipment in substations |
Monitoring different voltage grade lines requires different equipment. Digital substations are not applicable. |
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Growth |
Multiple devices in the same area can form a network fault location system, which can monitor multiple lines of the power grid and have higher accuracy of fault location. |
Fault location for single line |
Fault location for single line
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Solution：
Composition of line fault location system (the main station, the sub station, the communication network):
Main station: analyze and calculate the fault information on the sub station, and accurately calibrate the rod number of the transmission line fault with the GIS geographic information system, and can realize the Web release.
Substation: installed in substation, responsible for collecting high frequency signal of line fault, and can store and query high-frequency signals collected locally.
Communication network: responsible for information transmission between the main stations, the power system optical fiber communication network can also be used, or the 2M network can be used.
Technical advantages:
Based on the analysis and summary of the existing operation fault location system database, the adaptive model based on the wide area network fault location is constructed to warn the potential fault, enhance the effectiveness of the fault signal detection and improve the accuracy of the fault location.
The system uses special signal sensor to extract the signal, not only can locate the line metal fault accurately, but also can locate the fault of the line high resistance grounding fault. At the same time, it can detect and locate the fault without blind area, the positioning error is 150m, and the success rate of reliable positioning is over 90%.
