Control method for integrated electric drive and charger apparatus for a grid enabled vehicle

A system 20 for a grid-enabled vehicle that integrates vehicle traction comprises a bi-directional DC energy source 22, an electric machine 28 including a rotor, a stator, a first winding 36 and a second winding 38. The stator carries the first winding. The system further comprises a first bidirectional converter 24 connected to the first winding and including an input port 30 configured to be coupled to the grid, and a second bidirectional converter 26 through which the second winding is connected to the bi-directional DC energy source. A method of controlling the system comprises coupling the first bidirectional converter to the grid, and operating the first bidirectional converter according to a field-oriented current space vector method so as to convert grid-supplied electrical energy into an alternating voltage waveform. Said operation comprises periodically switching a current vector in a d-q reference frame between diametrically opposed first and second vector points, the current vector being disposed at an angle relative to the d-axis to define a d-axis component value and a q-axis component value. The bi-directional DC energy source is charged using an induced alternating voltage waveform in the second winding arising through magnetic coupling between the first and second windings.