Abstract
In this paper, a measuring method based upon the torque feedback principle is proposed for measuring the power of a rotating machinery turning forward and reverse directions periodically and is applied to measure the energy converting efficiency of a wave energy converter.
In the primary stage of a wave energy converter, it is often necessary to measure the converted power by using the linear or rotary motions which moving directions change at a very low frequency. when the power of walking motions of men and animals is desired to be measured, the same problem will be faced. In these cases, it is difficult to use the conventional power measuring method for the machines which rotate only in one direction.
A measuring instrument consisting of a tacho-generator which detects the angular velocity and a torque motor which generates the brake torque proportional to the output of the tacho-generator so as to give the brake torque to the movement of the converter is devised. As the result of the application of this measuring instrument to the wave energy converter consisting of 2 floating bodies and a connecting rod, it is found that this measuring instrument is very accurate. Moreover, it is also the special feature of this instrument that the optimum point of converting efficiency can be obtained during operation since the brake torque generation can be controlled precisely from the outside of this system.
