On the Modern Solutions on Combined Machinery and Electronic Generating Systems for Small-Scale Power Facilities and Movable Objects
It is often believed that wind energy today is not always a profitable (in business terms) electricity generating technology. There is no doubt, however, that this environmentally clean technology with an inexhaustible resource implies its widespread use not only in the near future, but also nowadays under the appropriate conditions. In the final analysis, the interests of national security play a decisive role here, and, hence, the priority in solving the problem of power supply availability and the country’s security through the development of small-scale power generation (including, above all, the development of wind and hydropower industries) remains to be decided at the state level. Higher reliability of autonomous power supply (APS) and the renewable nature of energy resources used by it are the factors determining the fundamental difference between the APS for geographically dispersed consumers that are located far away from centralized power lines. The first design-and-organizational objective, which should be addressed in a particular country, is to compile a map of the distribution of wind and hydropower resources, based on which the advisability of using this technology should be analyzed. The second objective is to use the most rational technical solutions for wind (hydro) electrical installations. The article considers the structures of alternative versions of installations that are presented only by a comprehensive electrical package in the form of a combined machine-and-electronic generating system of the «variable speed-constant frequency» type. Synchronous and asynchronous machines are considered as converters of mechanical energy into electrical energy. The second version implies the use of induction machines with a squirrel-cage rotor and with a phase rotor. The mechanical energy converters operate jointly with an electronic frequency converter, which can be embodied as two series-connected four-quadrant converters. The article presents a brief comparative analysis of five wind turbine structures operating autonomously and in parallel with the grid. The results of computer simulation of the most rational options are presented. The aim of the study is to give an idea to the developers about the modern solutions for constructing comprehensive electrical packages for wind power systems and to simplify the procedure of selecting the most rational solution.