Analysis and simulation of static kramer drive under steady-state conditions

Abstract

A rigorous analysis of the static Kramer drive under steady-state conditions is described in which stator variables are transformed on to a frame of reference which is stationary with respect to the rotor. For constant-speed operation the system equations are reduced to a set of linear differential equations with constant coefficients which are solved to predict drive waveforms, allowing for inverter DC-voltage waveform, DC-link-current ripple and the changing states of conduction of the rotor rectifier diodes. Eigenvalue and eigenvector techniques are applied to obtain analytical expressions which greatly reduce computation time. The harmonic content of the various current waveforms is examined, and the analysis used to examine certain features of drive performance such as stator-current pulsations at certain speeds. Results were verified experimentally and display very good agreement with measurement.