Design and Simulation of Water Level Monitoring and Control System in Mini Hydro Power Plant Mulyono Department of Mechanical Engineering Swiss German University Tangerang 15143, Indonesia Email: moeloviana@yahoo.co.id Hanny J. Berchmans Department of Mechanical Engineering Swiss German University Tangerang 15143, Indonesia Abstract—In common mini hydro power plants in Indonesia, the control of water levels in intake, sand-trap and head pond is carried out manually. This conventional manual control system may cause damages of waterway and all its components due to overflow or transient flow of water during load shedding or black out of electricity grid. The damages eventually may increase cost of maintenance and increase the risk of waterway collapse or excessive water hammer in penstock pipe. This type of collapses often happen in many mini hydro power plants in Indonesia. The risk of damages can be reduced by installing water level control and monitoring system in all key water way components such as in intake, sand-trap and head pond. Some other mini hydro power plants have installed water level control and monitoring system. But the price of such control system is still very expensive and high operation and maintenance cost. Thus, this thesis work designs and simulates simple and inexpensive the water level control and monitoring system for a mini hydro power plant. In this thesis work, the design and simulation of the water level control and monitoring system are carried out by a simulated three water tanks where the water levels in the tanks are monitored and controlled by using ultrasonic level sensors and motorized valves respectively. A simple and inexpensive Arduino based water level control and monitoring system is successfully designed to fulfil the requirement of quick or fast respond for water level control in the simulated model. Keywords: Water Level, Mini Hydro Power Plant, Control and Monitoring, Ultra Sonic Sensor, Arduino. I. I NTRODUCTION Hydroelectric power plant is a renewable energy generation power plant that utilised potential energy of water. Small- scale hydropower plant first used of electricity generation in Indonesia the early of the 20th century. Many mini hydro power plants have been developed in most parts of the world, including Indonesia, to generate electricity for the need of electrification in rural area. Basically the work of a mini hydro power plant is explained in this way: (i) water from the river is flowed through an intake, where the water level in intake is controlled by a dam and two (2) water gates, (ii) water from intake then is flowed through a section channel to a sand trap, (iii) in the sand trap, the sand or soil that is deposited is taken, (iv) water then flows in long section of waterways into a head pound head. The water in the head pond then is flowed through pen- stock. Kinetic energy of water in the penstock is used to drive the hydraulic turbine. In the hydraulic turbine, kinetic energy of water in converted into mechanical energy of hy- draulic turbine. Then by a generator, the mechanical energy of hydraulic turbine is converted into electrical energy. The produced electricity is transported to electricity grid to fulfil the electricity demand. A mini hydro power in a run of river type of hydro power plat where it does not need large dams for water storage. The mini hydro power plant system is a low-cost way to generate electricity for rural people area in the remote area. This type of power plant can also prevent environmental damage such as flooding. A simple schematic diagram of mini hydro power plant shown in Figure 1. Fig. 1. The Mini Hydro Power Plant II. OBJECTIVES The objectives of the research are: • Design and simulate a model of water level monitoring and control system for mini hydro power to monitor and regulate the opening of the valve so that the operation of the can be done safely and effectively at any load or transient condition in the upstream and downstream of the power plant. • Design a control that can prevent water in the channel and head pond tank from overflowing when the penstock pipe closes suddenly. Conference on Management and Engineering in Industry (CMEI) , 13