Study On Protection And Intelligent Diagnosis System For Air Compressor

According to the actual condition of the under-mine low-voltage power grid in our country and the status quo of the air compressor used in mine, this dissertation analyzes all kinds of faults which may occur during the working process of the air compressor in the power grid, for example, electricity leakage, phase break/unbalance, overload, overvoltage/undervoltage, shortcircuit and non-electricity faults. Corresponding protection principle and arithmetic are put forward aiming at the fault characteristics. Relevant research about the air compressor protection and the intelligent diagnosis system is done. Electro-magnetic transient simulation software EMTDC is used to carry out simulation on the counter-emf phenomenon when the power supply of the motor is suddenly cut off. And its influence to the earth leakage lockout protection of the system is analyzed and studied. Through EMTDC simulation and calculation on the normal faults including electrical (phase break) and mechanical (rotor lock) faults, results in compliance with the theoretical value are achieved, hence a simulation platform is provided for the motor fault-handling research. Lastly, a brief discussion is carried out about the later work direction. Intelligent diagnosis technology such as Multi-agent system and Self-adaptive fuzzy control which are used in the relay protection system makes every agent flexible, quick to make decisions and correct to judge. Agents are applied according to the functions, which makes the system operating in a parallel mode and the decision speed is enhanced. The intelligentization of the alternating between the status judgment and the Agents further improves the adaptability of the system. dsPIC30F series micro processor which has a good performance-price ratio is chosen, combined with ATmega128, to build an effective and reliable firmware system. The software is based onμC/OS-II real-time operation system. Making full use of the various services whichμC/OS-II provides and through reasonable task-planning, a robust, reliable and scalable protection system is constructed.Tests have proven that the veracity, maintainability and reliability of the measure-control protection system are greatly enhanced.