Research Of Large Capacity Transformer Cooling Control Device Based On PLC

To the problem exit in the cooling control device for large capacity transformer , such as the complicated control circuit, low reliability, high fault rate , large control error, the principle and implementation of a cooling control device for forced oil-circulated air-cooled large capacity transformer based on PLC is presented in this paper. The device use siemens S7-200 PLC(CPU224) as controller, construct the cooling control system for transformer; the transformer temperature as the control system's controlled variable, use control strategy of switch on and off value, which have margin in them, combine the accumulate operating time and continual operating time of cooling units, realize balanced, integrated auto control of cooling device. Beside this, the device has other functions such as, communication and remote surveillance, fault locating, information display. The devices have been used in Pumei and Jiaomei 220kV transformer substation, Zhangzhou, Fujian province. The results of operations show that the device is of high operation reliability, accurate control, can prolong the service life of the cooling unit. The requirements of the intelligent control for large capacity transformer cooling device are satisfied.