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Some Studies And Applications On Digital Protection Of High-Voltage Switchgear In Underground Coal Mine

Posted on:2011-02-14Degree:DoctorType:Dissertation
Country:ChinaCandidate:X L YangFull Text:PDF
GTID:1102360305485124Subject:Control theory and control engineering
Abstract/Summary:PDF Full Text Request
With the development of coal production mechanization and automation, Power capacity, voltage and the supplying distance increase greatly. It needs the higher requirements of reliability, safety and continuity for mine power system. As the mainain protection of terminal line of high voltage power supply system in Underground mines, the high-voltage mining flame-proof feeder switch has the protect functions when in the faults of cable and transformer short-circuit, over-current, leakage and cable damage, etc.With the rapid development of production, the contradiction between production and safety is serious. The existing technology and equipment cannot satisfy the request of production safety, especially cannot meet the safety of digital era. Production safety in coal mine demands more reliable and sensitive, accurate and safe digital products and equipment. Under this background, we spread out research around the problems involved in the development of high-voltage switchgear digital protection system. The paper work have made some achievements which have practical significance and economic value to enhance the performance of the protection system, to improve production safety of coal mines and Power automation. The main jobs are as follows:The paper carry out research on the common algorithms in digital protection, especially focusing on the characteristics which the fault current and voltage shown under power system fault situations. And puts forward a new kind of fourier algorithm, theoretical analysis and simulation results shows that the new algorithm can effectively inhibit the decaying amperiodic components in the fault signals. The amplitude and phase computed have high precision which provide the basis for the amplitude and phase comparison in relay protection.In coal mine, the signals are interferenced easily, The signal pre-processing is necessary. This paper proposes an improved particle swarm algorithm based on fusion strategy, which used to optimize the lowpass FIR DF and stopband FIR DF. Simulation results show the effectiveness of the new method.The paper proposed the fault diagnosis method based on wavelet packet feature extraction and BP-PSO ANN. Simulation results demonstrate the validity of the proposed method.Make full use of the rich bit instructions in microcontroller, the paper proposed a new key state identification algorithm, the operation corresponding program shows the goog performance of the algorithm.Complete the hardware and software development of the protection system. First, use lowpass and stopband DF to preprocess the sampled data, then, use the proposed fourior algorithm to realize the Phase sensitive protection and the selective leakage protection. The software effective simplified the design of hardware circuit.Finally, Give a practical application of the protection system, the results are good. It has vital significance on improving the Selective and reliability of protection system, power supply quality and reducing equipment failure in mining area.
Keywords/Search Tags:microcomputer relay protection, fourier algorithm, particle swarm algorithm, phase sensitive protection, wavelet packet feature extraction, fault diagnosis, flag
PDF Full Text Request
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