Explaining Power System Operation to Nonengineers

It is sometimes difficult to explain how a power system works, especially for people who have not studied electrical engineering. This article shows how the interactions of a power system and its components can be explained using the parallel with a tandem bicycle. The active power balance in the power system is modeled by the parallel of keeping a constant speed of the bike, while the reactive power balance is represented with the fact that the bike has to be kept on the road without overturning. Consider a long tandem bicycle. The bike is made of flexible material, and the chains between the different sprockets under the different cyclists are slightly elastic. When the bike is standing still, all the pedals on one side of the bike will be at exactly the same position, e.g., at the bottom position. Assume also that the bike is run on a flat, straight road, and the aim is to keep a constant speed of the bike and the bike should be kept in an upright position. The wheel losses and air resistance are neglected. Many functions in the power system can be illustrated with the mechanical parallel of a tandem bike that is kept running at a constant speed (constant frequency) and in an upright position (voltages at 1 pu). The parallel gives a good visualization of phenomena such as active power balance, frequency control, asynchronous machine slip, reactive power balance, and voltage control.