Fault Diagnosis System And Online Verification Of Relay Protection Sensitivities In Urban Power Network

Works stated in this thesis are completed with a practical project "Intelligent Decision Supporting System on Urban High Voltage Systems", which are imbursed by the important scientific project in Henan province. According to the combination of theoretical analysis and the actual need of Power Branch, the data resource of SCAD A system under control center based on unmanned substations is fully used to develop the fault diagnosis system and Verification of Relay Protection Sensitivities based on the Topology Configuration of Real-Time and Emulation State system. The system is applied to a means of online fault diagnosing and a measure of real- time monitoring relay protection sensitivities. And following works have been illustrated.In the works, database system divided into real-time database and relational database is established for different functions. On the basis of the databases, a programme is empoldered in order to better synthetically manage the relay information and lighten the burden of operators, besides an efficient, speedy, flexible database supporting system is established.Because there are more or less limitations in the real-time data collected through SCADA system, the information must be deal with properly before using them. Through researching these characteristics of real-time data received deeply, some good measures are put forward and accepted to improve the fault-tolerance performance of the fault diagnosis system in the thesis, such as advance disposing of real-time switch information and instauration of dummy switch etc.Based on the data information received, three starting arithmetic is developed in the thesis. While SOE information is perfect, the starting arithmetic is used with SOE general signal; by contraries, if SOE information is not perfect, another conjoint starting arithmetic is used with the fault general signal in SOE information and relay action signal in YX information. In addition, through discussing the action mechanism of CHZ, difference of Permanent Fault and Impermanent Fault is ensured in fault starting. During these measures, the fault diagnoses can response the starting signal accurately and sensitively. Using the method, the probability of improper startup can be lessened greatly.Considering the hierarchical characteristics of post-fault signals, an intelligentfault diagnosis means is proposed to identify fault components rapidly and exactly, which is based on the action information of circuit breakers and relays with using partial electric qualities under the state of fault to verify fault components further. The algorithm has better adaptability for different network configurations and can be generally employed. It not only adapts to the state while only switches act, but also to the state while relay protections act; In addition, through using electric information collected by microcomputer protection, more accurate results are gained.In verifying of relay protection sensitivities, a network portioning method combining with graphic interface is proposed. It can online track the varieties of network, accordingly it can satisfy real-time and emulation analysis of topological configuration.With the real-time network configuration and nodal admittance matrix analyzed, the short-circuit calculation is carried out; by means of an expert system, the verification of protection sensitivities has been achieved. This sensitivity verification can also be used for any network configuration modified from current power network connection.A good short circuit program is empoldered with holding less memory and more rapid calculate ability. At the same time, the program applies the result to the module of verifying the electric devices' stability.With these functional modules being applied to practices, these functions are proved reliable and achieved the demands expected. They become much useful for improving the security and reliability of system operation.