Current pulsation of induction motor driving a reciprocating compressor

With a reciprocating-compressor drive, large errors in the prediction of current pulsation can occur when the induction-motor steady-state characteristics are used in the analytical solution. A numerical solution, in which the induction motor is represented by its general 2-axis equations, is presented, and the results favourably compared with test measurements. The currently used equation for induction-motor compressor factor is shown to be unsatisfactory, and a revision, involving the motor synchronising capability, is proposed.