Wind-Power Plant

a wind-energy installation that converts the kinetic energy of the wind into electrical energy. A wind-power plant consists of a wind engine, a generator of electrical current, automatic devices for controlling the operation of the wind engine and generator, and buildings for their installation and maintenance. In most cases, wind-power plants are used as a source of electrical energy of relatively low power in places characterized by good wind conditions (a mean annual wind velocity of over 5 m/sec) and removed from the networks of centralized electric-power distribution (the arctic, coastal zones of the Caspian Sea and the Sea of Okhotsk, steppes, deserts, and semideserts). The use of wind-power plants is most promising in agriculture.

The first wind-power plant in the world, with a capacity of 8 kilowatts (kW) and with an inertial accumulator, was built in 1929-30 in the USSR (in the city of Kursk) according to the design of the Soviet inventor A. G.Ufimtsev and Professor V. P. Vetchinkin. In 1931 a wind-power plant with a capacity of 100 kW was erected for parallel operation with the powerful thermal electric power plant that supplies power for the city of Sevastopol’. In the 1950’s several 30-kW wind-power plants with a thermal standby were built, as well as a multiunt plant in Kazakhstan with a capacity of 400 kW, consisting of 12 plants working parallel with a Diesel electric-power plant. In France a wind-power plant with a capacity of 640 kW is in operation. The most powerful wind-power plant (1.25-MW) has been built in the USA. The smallest wind-power plants have a capacity of 100 W. Wind-power plants throughout the world number over 70,000 (according to UNESCO data for 1967).

Wind-power plants of small (up to 3 kW) capacity have generators of direct or alternating current and operate with gangs of electrochemical storage batteries, which not only store energy against calm periods but also smooth over the voltage pulsations. Wind-power plants of medium and high capacity generate alternating current. For isolated operation, in order to improve the quality of the energy and its short-term accumulation, wind-power plants are equipped with inertial accumulators and electrical voltage regulators. The use of a wind-power plant together with a thermal (standby) engine or parallel with a non-wind-driven electric-power plant is the most efficient.

In the widely used wind-power plants, a high-speed wind-wheel is connected to the generator by a step-up two-stage or three-stage reduction gear, all the principal mechanisms are located in the head, and energy from the generator is transmitted to the user through an electrical cable; the electrical regulating apparatus is usually located in a building next to the tower. Such wind-power plants require less metal, but they create certain difficulties in operation. Wind-power plants with two reduction gears (upper and lower) connected by a vertical mechanical transmission are encountered less frequently. In this case the generator is placed below, in the building. Maintenance and repair of equipment are simpler in such wind-power plants, but their efficiency is lower owing to the expenditure of part of the energy on friction in the supplementary elements of the mechanical transmission. Wind-power plants with pneumatic power transmission, which was proposed by the French engineer H. Andeae, are also in use. In this type, the highspeed windwheel has hollow blades through whose channels air is ejected with great rapidity during rotation. A vacuum is created in the tower, and the movement of air sucked in from the atmosphere rotates a pneumatic turbine connected to the generator. This type of wind-power plant has a small overload factor and requires less metal than ordinary wind-power plants; it is also reliable in operation, but it is structurally more complex and less efficient. For the reliable limitation of output during times of great wind velocity (gales) and to maintain constant frequency of rotation and generator voltage complex automatic systems of aerodynamic and electrical regulation of the parameters of the wind-power plant and also automatically regulated fully variable (friction) transmission from the windmill to the generator, are used. This type of fully variable transmission has been installed in the D-12 wind-power plants constructed in the USSR in 1957. With parallel operation, devices are used that limit overload (asynchronous sliding couplings and so on).

Work on the construction of more modern and economical wind-power plants is under way in the USSR, Great Britain, France, the Federal Republic of Germany, Canada, and other countries. Plans for wind-power plants with a capacity of up to 5 MW have been developed (the Philippines, 1967). The use of fully automated wind-power plants, as well as of tropopausal (high-altitude) plants (which are a complex consisting of a windwheel attached to the envelope of an aerostat, an electric generator, and automatic control and regulation apparatus placed inside the envelope—in the gondola) is planned. The aerostat (dirigible) ascends to an altitude of 8-12 km, in the zone of constant, high-velocity (up to 100 m/sec) air currents.