Intelligent PLC based transformer cooling control system

Abstract

Distribution network experiences distinct changes from low to high load level every day. Electrical power losses in distribution systems correspond to about 70 percent of the total losses in electrical power systems. One of the most severe problems faced is power loss during the operation of transformer. Transformer plays a vital role in transmission and distribution system. There are many problems associated with power loss in transformer but this paper mainly focuses on efficient cooling system designed for overcoming heating and insulation losses. With the implementation of smart grid and smart cities, the traditional control mode of transformer's cooling system cannot meet the new demand. Ideally PLC is used for online monitoring and data recording. In our paper, we have proposed an intelligent cooling system based on Programmable Logic Controller (PLC) which eradicates the problem of manual transformer cooling control system by automatically switching between the cooling banks. The cooling system in our paper comprises of three cooling banks, each having a fan and a pump. At a time, two out of three cooling banks will be operating. In case of failure of any one of the operating banks, the third bank will automatically switch on in place of the faulty bank. Hence third bank will continue to operate until faulty bank is repaired. This switching between cooling banks is PLC controlled and thus eradicates the errors caused by human intervention. Along with this, continuous monitoring and data recording is simultaneously done. We have also focused upon proper utilization of standby bank by means of periodic switching. PLC logic is used for controlling all the components which are involved in the protection of transformer and also using the component only when needed eradicates the wastage of power and unnecessary operations. Human Machine Interface (HMI) can also be used for complete visualization of the process in the control room.