The invention relates to a rotating electric machine, such as a dynamometer. The rotor of the machine comprises a circular row of resultant magnetic poles of which the polarity forms an alternation of opposed poles. The resultant poles each include a pair of permanent magnets in a “V”, each equipped with a north pole N, a south pole S, and opposed faces, where the magnet poles are located. In each resultant pole the magnets are disposed so as to have faces having identical polarities, which faces are oriented radially outwardly, facing towards one another, thus forming therebetween an angle β between 90° and 110°, which makes it possible to increase the efficiency. The invention also relates to a turbomachine test stand equipped with a dynamometer enabling a recovery of electrical energy. The invention also relates to a hybrid motor vehicle propelled by the rotating electric machine.