The aim of this paper is to develop the theoretical basis of mechatronic systems construction using the principal components projection method for conducting natural model measurements of mechatronic systems parameters. It is difficult to name a technical sphere where mechatronic systems aren't applied. They can be found in many household appliances, communication devices, they make an integral part of electrical machinery, many devices of industrial automation, control equipment and protection of various electrical installations. To conduct natural model measurements, we need models connecting various parameters of mechatronic systems between each other.