The Research About The Buchholz Relay Test Equipment

The buchholz relay is very important in the main protection components of the oilcooling transformer. It can monitor most of the internal faults to the transformer and helps theoperation and maintenance testing people predict and analyze the accident. When the slight orserious faults in the transformer occurs, it emits light alarm or interrupts the transformer fromthe power grid directly, to protect the security of the transformer and the power grid. In thispaper, in order to improve the capability of the regular checking on the scene for gas relay,with the research of the control to release the compressed air energy directionally andquantitatively, we designed a highly automated portable gas relay testing device. The maincontents of the paper are:The first part, via the introduction to the working principle and the national testingstandard, the paper explained the aim of the research was going to realize the function of theairtight test, capacity test and the flow velocity measurement test to the buchholz relay.The second part, through the contrastive analysis of the representative products elicit thatthe emphasis of the study is the flow velocity measurement test. Because, the difference of thevelocity test implementation scheme effect to the kinds of power supply, the size and weightof the whole device.The third part, the paper introduces the basic working principle, the structure principleand key components selection, and the device of velocity measurement process ofmathematical modeling.The fourth part, according to sequence that from the core to the peripheral device, thepaper introduced the minimum system circuit based on STM32F107processor chip, the relaycontrol circuit, the trigger detection circuit, the signal conditioning circuit, the USB circuit,the serial communication circuit and power circuit.The fifth part, the paper numbered the associated device in the program editing,described the action process of the devices in the three trials, draw the program flow chart,and displayed the man-machine interface.The sixth part, for assessing the influence to the flow field in the device and the testresults by using the different diameter flange in one device to adapt different diameter gasrelays for improve the applicability of the device, the paper used the FLUENT fluidsimulation software to simulate the velocity and pressure distribution in different measuring diameter of gas relay, and analyzed the results of the volume measurement and flow velocitymeasurement experiment.Finally, the paper summarized the advantage of the type gas relay test device, and gavesome suggestions on the development of this kind of the device in the future.