Resonant behavior of electric drives of mining machines

Abstract

The global mineral market situation calls for particular attention to energy-saving mining technologies aimed at cost-saving of the production. One of the common methods of mining is rotary drilling. This process consumes very much energy; for this reason, energy saving of drilling owing to optimized operation of the electric drives in the cutting heads is of the current concern. The proposed mathematical model of an electric drive allows studying the drive behavior based on the highest energy efficiency criterion. The optimized behavior can be reached using the efficient law of motion of a cutting head along a swinging trajectory. This dynamic process becomes possible through forced introduction of an electric drive into the resonant mode, i.e. when the oscillation frequency of the disturbance coincides with the free frequency of the electromechanical system. It is noteworthy that the electric drive control should ensure adjustability of specific resonance frequency, option of limitation of current and speed amplitudes and minimization of infl uence of harmonic distortion of electric energy characteristics during operation of converter installations. The mathematical model allows having a series of relations between PID-regulator parameters under diff erent values of external disturbance, which makes it possible to design an electric drive for cutting heads of mining machines at the increased efficiency and decreased energy consumption.