Method and system for controlling vibrations in borehole equipment

Vibrations in borehole equipment are controlled by defining the energy flow through the equipment as a product of an "across" variable times a "through" variable, wherein fluctuations in one variable are measured and the energy flow is controlled by adjusting the other variable in response to the measured fluctuations in said one variable. Suitable variables for defining the energy flow are voltage times current of an electrical drive, pressure times flowrate of a hydraulic drive, or torque times angular velocity of any rotary drive.