| As the production level of coal mines continues to improve in China and the requirement on coal mines'yield and power supply safety is strengthened, which raises higher and newer requirements on protection, testing, management and maintainece of the entire underground power supply system and relative electric equipments. To some extent, much progress has been made on the coal mine protective relaying products in China, while there are still some products cannot meet the requirement of coal mine production. The limitations have been known by the society, e.g. some protective relaying products'function is relatively simple; in most situations one device only protects one type of power transmission and distribution, which makes the entire protective relaying system too big and inconvenient for debugging or maintenance. Therefore, due to the insufficiency of existing protective devices, it is quite necessary to develop a comprehensive protective device which could simultaneously protect high voltage lines, transformers and motors via software settings.In this article, based on researches on Matlab/Simulink simulation of usual malfunctions of coal mine high voltage grid, relative transformers and critical electromotor, and malfunction wave pattern was obtained during the simulation, then combining with all kinds of protection operating principle and existing problems of existing high voltage switch gear protective system, came up with corresponding protective methods. Calculations have been done according to all kinds of protections'specific criteria of protective programs, which help for model selection regarding with the required devices of protective system; DSP chip TMS320LF2407, and single chip computer AT89C51 compounding worked double CPU structure hard ware circuit has been designed as the control system of comprehensive protective station. This type of hardware circuit structure could effectively realize all kinds of protection of power supply system and relative electric equipment underground, and then realize comprehensive protective functions. |
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