Design And Implementation Of Automatic Testing Device For Power Transformer Test Based On AVR Microcontroller

When power transformer tests are performed in many domestic transformermanufacturers and power grid corporations at present, the traditional method is commonlyused in which analog instruments (voltmeter, ammeter, wattmeter) are manually controlledand read. But because the operations of stepping test voltage up and down and switching thetaps of current transformers and reading meters are manually controlled, there are inevitablehuman errors which includes control misconduct and read error and so on in the test mode.And it also has shortcomings that the analog instrument’s wiring is complex, reading isdifficult and recording is inconvenient. The computer-based testing system for powertransformer test is used by some companies. However, because these systems have somequestions such as the equipment is relatively backward, the projects of testing are single andthe automation degree of testing process is low, it is difficult for them to meet the needs of thecurrent development. In addition, these systems also have disadvantages such as huge volumeand high cost. Therefore, in order to meet the current demand of performing powertransformer test, it has practical significance to develop a power transformer automatic testsystem which has high-precision, high automation degree and low cost.This paper provides a design and implementation of automatic testing device for powertransformer test based on AVR microcontroller after power transformer test (mainly no-loadtest and load test) has been studied. The device, composed of high speed and high precisionA/D converter MAX1320and AVR microcontroller ATmege128taken as the core, canperform automatic tests for no-load test and load test of power transformers, which improvesthe efficiency and avoids human errors. In addition, test results and historical data can beviewed (printed or transported) and system parameters can be set if needed.This paper firstly gives the overall structure of hardware of automatic testing device forpower transformer test, and then chooses the circuit modules which can achieve the functionsof the device. The circuit modules include a data acquisition circuit, the MCU main circuit, acommunication interface circuit, the test control circuit and a liquid crystal display circuit.Then the specific properties of components in respective circuit and interface circuit betweendifferent modules are described. The schematic and PCB documents are ploted overall with Protel software platform. Finally, this paper develops the program of the device by using theC language, which can achieve the various functions of the device.The automatic testing device for power transformer tests based on AVR microcontrollerhas strong expansibility and flexibility, and it also has high-performance of high efficiency,low error, convenient operation, small size and low cost. And it has passed the tests in thelaboratory and used well in the field.