Digital Automatic Closing Fmergency Sources Device Studies

In this thesis, a new principle of automatic closing emergency sources device with adaptability was proposed. And a new type of such device has been developed, based on the hardware platform with the kernel of 32-bit micro-controller unit. The device is suitable to 380-220kv substation's automatic closing emergency sources control of lines, two-winding transformers or three-winding transformers. The device has the ability to automatically judge the operation mode and realize the function of automatic closing emergency sources in different operation modes without the manipulation of operant, which meets the requirements of substation automation and especially suits the unmanned operation mode.MC68376 has the characteristics of high speed, powerful function and plentiful instructions. In this thesis, MCU table look-up and interpolate instruction was employed in a new fast integer evolution algorithm that has high precision. The device adopted this algorithm and gained good results. In order to improve reliability and simplify the hardware design, many new I2C bus elements were used to realize binary input, logic output, clock functions and storing settings and reports. By simulating I2C bus data transfer, the MCU realized writing and reading data from each element The whole hardware system's structure is compact and reasonable, and the device has high reliability, stability and immunity to disturbance.Theoretic analysis and practical experiences have proved the reliability, high-speed and flexibility of QADC. Compared with 12-bit A/D, the precision of QADC is not low.SingleStep was applied to develop MC68376. The software system with modularization structure not only realized the work principle of the device, but also completed the design of a brand-new user interface illustrated by icons that increased the device's flexibility.