The Application of AT89C52 Microcomputer-unit in the Temperature On-line Test Control System of Transformer

摘要

In the course of the rapid development of electric-equipment and electric-industiy, transformer plays a very important role At present, there are two types of transformer: it's oil-immersed transformer and dry-type transformer. Because the dried transformer has a lot of advantages, the oil-immersed transfer will be displaced by the dry-type transformer. But the temperature that in the course of using of transformer running must be controlled strictly, otherwise, the transformer will be destroyed to some extent or burned causing dire consequences to the power-supplying system. So we must test and control the temperature of the transformer in real times. This is the area that my paper aims to touch upon. As for the method to control the temperature, in my paper, a temperature testing system that is based on AT89C52 Microcomputer-unit as the center of data processing and system control was designed. A kind of platinum resistor, namely PtlOO, was utilized to collect the temperature signals, and then the signal was processed by a series of circuit, such as the temperature /voltage transform-circuit, amplifier circuit and the filter circuit. In the end, the signal was transformed digital-signal by a A/D circuit into the AT89C52 Microcomputer-unit system. The MCU-system can accomplish some manipulations such as sending an alarming to indicate over-temperature, starting or stopping the refrigerated fan and auto-shut up switch according to the temperature signals. All these manipulations will make the transformer reliable in the course of running. In the paper we carefully study the nonlinear-character of the PtlOO resistor, and bring about some optimization method for platinum resistor to make the collected signal more precise. Because the circumstance where the test system locate has a great deal of electromagnetic interfere, we designed many anti-interfere ways including a "Watchdog circuit" to ensure the test-system more stable and more reliable. To make the system running, relevant software was produced, and the software include a little of special program that avoid the program running in disorder. In practice test, the experiment data and reaction of system indicate that the state of system can arrive at the criterion. We can draw the conclusion that the test and control system can be used in our practice.