.110 Kv Dry-type Transformers And Control System

The d ry-type t ransformers have been widely used in high buildings and power stations in cities due to its superiorities of flame retardancy, safety, easy maintenance, small volume, etc. Following the ever-growing urbanization, 110kV level terminal will be the emphases of city power supply to ensure its availability in the downtown. In 1999, the first 110kV dry-type transformer was successfully made by JMC GROUP Company, Shandong, China. Now this is the highest voltage level epoxy resin casting dry-type transformer in the world. 110kV dry-type transformer is a kind of new power transmission transformer.For dry-type transformer, its operation safety and durability is mainly depending on safety and reliability of insulations of transformer winding. Insulation will be destroyed when winding temperature exceeds the tolerable insulation temperature. Besides over voltage, under voltage and over loading, this is one of the major reasons leading to abnormal performance of transformer. Therefore, it's very important to monitor the transformer's running temperature, running voltage and running current and to control its alarm.In this system, winding temperature is measured by infrared temperature sensor, core temperature is measured by Pt100 thermo resistant, voltage is measured by voltage mutual inductor, and current is measured by current transmitter. The selected PLC is SIEMENS S7-300 PLC, it processes the data with thyristor controller. Touching indicator is SIEMENS TP 270 6' touching human machine interface (HMI). Between HMI and PLC MPI communication mode was used.Aiming at the problem of high -tension breakdown in the high -tension side of the transformer, this paper introduced a kind of new measurements employing an infrared temperature sensor to replace Pt resistance, and analyzed its operating principles and characteristics. At the same time, this system adopts PLC and HMI to process and display all kinds of signals to further improve the safety and reliability ofthe whole system. Installing fans and adjusting their voltage and speed to cool the transformer is favorable to improve the loading ability of the transformer with energy saving and low running noise.