Vernier Reluctance Machines Research Articles

Analysis of the Power Factor of Stator DC-Excited Vernier Reluctance Machines

Stator dc-excited vernier reluctance machines (dc-VRMs) are a kind of a novel vernier reluctance synchronous machine that employs doubly salient structures; their innovations include stator concentrated dc windings to generate the exciting field. Compared with the rotor wound field machines or stator/rotor PM synchronous machines, these machines are characterized by low cost due to the absence of PMs, a robust rotor structure, and a wide speed range resulting from the flexible stator dc exciting field. In this paper, with the proposed phasor diagram, the power factor of dc-VRMs is analyzed analytically and with the finite-element analysis, and the analysis results are confirmed with the experiment. It is found that, with constant slot sizes and slot fill, the power factor is mainly dependent on the ratio of the dc current to the armature winding current and also the ratio of the armature synchronous inductance to the mutual inductance between the field winding and the armature winding. However, torque will be sacrificed if measures are taken to further improve the power factor.

Study and experimentation of a rotor current excited Vernier reluctance machine aimed to direct-driven applications

The present paper deals with the study and experimentation of a rotor current excited Vernier reluctance machine. First, the structure is introduced and the conditions on the teeth and the polarity numbers necessary for the smooth running of such a structure are presented. Then, a simple procedure is given, based on some simplifying hypotheses, to obtain the initial geometrical and electrical sizes of a designed prototype. To validate the operating principle of the structure, a prototype is designed and studied using 2D FEM. Finally, this prototype was constructed and simulation results were compared to those obtained from the prototype.

Study of a Stator Current Excited Vernier Reluctance Machine

This paper deals with the study of a stator current excited Vernier reluctance machine. This structure is well known for operating at low speed and high torque. In the first part of this paper, we introduce an energetic model which yields the conditions on teeth and polarity numbers necessary for the smooth running of such a structure. Then, we give the procedure used to design a prototype. The second part is devoted to a brief look at the two-dimensional numerical approach used to model the machine. Finally, we present, and study, the constructed prototype. Different tests are performed, and the experimental values are compared to the calculated ones. We validate the operating principle of the current excited Vernier reluctance machine, and show its potential for low speed direct driven applications