Бесконтактный дисковый генератор на постоянных магнитах с переменным воздушным зазором

Abstract

Construction of inductor contactless electrical machine is introduced: generator with excitation from permanent magnets with the decreased moment of resistance at starting. Contactless disk-type multipolar generators with excitation from permanent magnets are becoming more common in small scale wind and hydropower generation now. It is known that this type of generators have characteristic disadvantages. In particular, these generators have the effect of magnetic freezing. The effect makes the start of rotation of windwheel and its subsequent acceleration to the rate rpm difficult. To eliminate the effect and to improve starting characteristics construction of generator with variable air gap is suggested. Variable air gap’s size is regulated by centrifugal regulator. For this purpose the part of magnetic circuit of rotor is a moving element. Air gap δ has its maximum value at a motionless rotor or low rotation angular frequency. Herewith magnetic linkage is minimal and generator has an insignificant resistive starting torque. With the increasing of angular frequency magnetic system of rotor moves along the axis of rotation by the force caused by centrifugal regulator. In result air gap decreases, magnetic system increases flux linkage and generator starts to produce electric energy. At reduction of angular rotation frequency under the influence of restoring spring magnetic system of a rotor moves to original position. Technical-economical effect comes from the decreasing of resistive torque of the inductor machine shaft, i.e. improvement of starting characteristics. On the construction of the described generator the patent of the Latvian republic is obtained in [1].