| The body of this thesis is the main content of the project "key technology of intelligent and combined electrical equipment for the coal main safety and efficiency" (serial number:2007BAB13B01), sponsored by the National Key Technology R&D Program of China. The work is proposed in order to meet the requirements of for modern mine which is the electric equipments are more reliable and high security. The coal mine modernization, equipment intelligence and production automation are listed as key constructive tasks in the 12th Five-Year Plan with development of the coal industry. The development of the coal industry, the model of a mine containing a well-side as well as a work face, and production transformation synthesized mechanization and electrication, the coal mining equipments development demands for towards the high-power, continuous and automated direction, which requires higher dements of mechanized coal face electrical equipment protection and control. The unattended integrated automation mining face is the development direction of modern mining technology. The systematic processes of exploiting mining coal should be done automatically and centralized control. Therefore, to achieve this goal, the different mining electric equipment must be centralized controlled and protected. The design of the comprehensive security system for undermine intelligent multi-loop design is of important practical significance.With the development of digital technology and computer science, digital protection is increasingly applied in the undermine power supply system and load control. These microprocessor-based protection systems are mostly single-CPU architecture. Signal acquisition, fault diagnosis and process control is processed by sole the CPU in the system. The CPU serially fulfils the tasks, so the processing speed is overly dependent on the CPU’s speed. Working on this way can’t meet the requirements for control and protection of multi-loop motors and is difficult to operate on time. Therefore, the multi-CPU structure is the developing trend of the microprocessor-based protection. The thesis has employed the multi-CPU control structure is proposed the AC sampling circuit by the CS5463 chip, and completed the protection of the multi-load is completed in this thesis. The main contents are as follows:The status and developing tendency of the domestic and foreign motor comprehensive insurance system is analyzed. The control principle and technical requirement are proposed, the structure of multi-CPU system control program is designed. The system with Multi-CPU control structure based on RS485 can flexibly adapt to the different loops, work in different voltage levels and in a variety of control methods to promot the production continuity and reliability by parameter tuning.The comprehensive leakage protection system consisting of the leakage locking, selective leakage protection and high voltage insulation is desigened. The leakage locking ensure that the leakage fault circuit can not be started, selective leakage protection can quickly determine if leakage occurs, and cut off the fault circuit and reduce losses, and high voltage insulation testing can truly test power supply cable and motor-to-ground insulation condition. The three complement ensure the security of the mine power supply by complementing each other.The mine low-voltage grid and motor failure mechanism are analyzed. The paper determines the on the basis of the reference to the relevant national standards fault protection scheme of the motor comprehensive insurance system fault protection scheme is designed laying a theoretical foundation for motor fault protection hardware and software design.The AC quantities measurement and treatment programs of protection system are designed. The system utilises AC sampling method based on the electricity acquisition chip CS5463 to collect load parameters. The program not only improves the acquisition accuracy, but reduces the workload of the CPU exchange acquisition of computing, which ensures fault diagnosis and processing system to run quickly and sensitivity.The upper computer system and lower computer system can exchange real-time data and the upper computer configures the branch line of the lower machine and the lower machines upload the data by the communication program. The real-time communication between the upper computer system and display screen can synchronously display the status of the motor control system.The application programs are designed through modular program design method for the upper system, lower system including main line and branch control and display. The HMI screens are exploited. These programs can fulfil the control of multi-load protection and display functions by running on the hardware.The EMC characteristic of the system is analyzed. The defensive measures are formulated in this thesis. System solves the system electromagnetic considering the grounding, the component selection, the PCB design, the treatment of the multi-CPU analog and digital ground which can improve the anti-jamming capability. It is shown that the system has strong anti-interference ability by EMC test. |
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