Modernization of lignite feeder control system using microcontroller with multidrop mode

Lignite handling plants are having number of conveyors and they are seen virtually. The control systems used for these conveyors are important for operating safe plant. In the existing control system, there are different modules and number of relays in control panel which makes the circuit very complex. There are four main feeder sets in each corner of a boiler. Each main feeder consists of four sub feeders and each sub-feeder consists of different modules. The different modules are Zero speed module, Chain positioned module, Coal flow/no flow module and Speed transmitter module. So, they occupy more space and needs more cables to communicate field and control panels. In this paper, a universal control panel is designed and simulated based on microcontroller. A simple cable communication interface is used between field and control panels with RS485 multi-drop mode facility.