22th Southern African Universities Power Engineering Conference, 30 - 31 January 2014, Durban, South Africa. 1. INTRODUCTION A constant supply of energy is a necessity for a country that wants an ever growing economy. To meet this demand, reliable electrical networks that consist of power lines are essential. Eskom is a power supplying company that have generated and sold over 225 000 Giga-Watt-hour in the year of 2011 and 2012, providing 45% of all the electricity used in Africa and 95% of all the electricity used in South-Africa [1]. In order to supply these enormous amounts of electricity thousands of kilometres of transmission lines is needed and is found all over Africa. 1.1 Problem Background The inspection of transmission lines are done annually in the form of line patrol, this is when a team from Eskom walk the line with the help of a motor vehicle to do a visual inspection on the condition of the transmission lines. Due to the vast amount of time needed to do this and the accessibility constrains due to rough terrain and obstacles, some of the inspections are done by a helicopter. According to an Eskom financial report of 2010 the expenses for these inspections run up to R36 million per year [2]. The use of a helicopter is a costly method to inspect transmission lines and thus an alternative solution to this problem needs to be found. It is proposed that a transmission line inspecting quadcopter needs to be developed that is more effective than the conventional methods of inspecting power transmission lines, in terms of time, safety and the costs involved. 1.2 Existing Solutions to the Problem Transmission lines are not an unfamiliar sight and ever since these lines made their appearance it was needed to be monitor by means of inspection. Over the years different solutions have been found to do this task. Transmission lines have been inspected on foot for a very long time as there was no better method available to perform this task. Power networks consist of thousands of kilometres of transmission lines and take a vast amount of time to inspect on foot if inspection is done thoroughly. Furthermore power lines are sometimes built in rough terrain that is difficult to access due to mountains, new development and height constrains. A method used with more success is to inspect the power lines with the help from a helicopter. This technique is very accurate because it can overcame the height constrains involved with power lines. Using a robot is the most recent solution and method of inspecting power transmission lines. This robot is developed to run on the earth wire of the line and with a camera in attached to the frame of the robot, photos and even videos can be recorded of the transmission line [3]. 2. PROPOSED SOLUTION In order to obtain a general feel and knowledge of what to expect during the design of this project, proper research had to be done on similar projects with roughly the same scope. The research revealed some important aspects that need more planning and time than other, stumbling stones to avoid, crucial approaches for success and risks involved in completing this project. The quadcopter needs to be able to fly along a power line for inspection purposes and should consist of an autopilot function. This function should provide the ability that the quadcopter can hover, do auto take-off and landing on command of the operator. The physical construction should be able to house and supply power to a monitoring system for the inspection purpose. The following key components were acknowledged to guarantee that the project is a success:  Custom development of a controller to achieve the desired features that the quadcopter should consist of.  Construction/Assembling of an appropriate frame/chassis.  Achieving lift-off, flying and movement of the quadcopter, by means of motors, propellers and speed control.  Design a monitoring system to do a visual inspection on the power lines.  Establish a remote communication system between quadcopter and operator.  Supplying power to all the components on the quadcopter. DEVELOPMENT OF A QUADCOPTER FOR POWER LINE INSPECTION N.J. Wilken and R. Gouws North West University, School of Electrical and Computer Engineering, Potchefstroom South-Africa, njwilken@gmail.com Abstract. The inspection of transmission lines is to be done annually. It is proposed that a quadcopter is used to do the inspection of these transmission lines. The modelling of the quadcopter was done by studying its physical characteristics and ultimately a mathematical model could be presented with the use of the Newton equations. The control strategy suitable of this project is the use of PD control, which will consist of four control loops combined as one. The prototype quadcopter is able to do transmission line inspections, is equipped with a monitoring system, move smoothly and have special features like stabilizing mode and altitude hold. Key Words. Quadcopter; PD Controller; Altitude Controller; Arduino and Controller simulation.