Double stator permanent magnet linear motor and design method for increasing magnetic field modulation

A double-stator linear Vernier permanent magnet DS-LVPM motor includes a primary, and a first secondary and a second secondary located on both sides of the primary and separated by an air gap;

• wherein
• the primary comprises a primary core, a permanent magnet and armature windings;
• the primary core comprises a number of primary core elements in which ends on both sides of the primary core elements comprise armature teeth;
• a middle of the primary core element comprises a yoke;
• and
• armature windings are wound around the armature teeth;
• wherein the primary is a bilaterally symmetrical structure;
• the primary core elements are a cross-shaped structure, wherein each primary core element constitutes a primary core element group, or N primary core elements in series constitutes the primary core element group (2≤N≤3);
• adjacent yokes of every two primary core element groups are connected with each other by the permanent magnet in the yoke, and the thickness of the permanent magnet in the vertical direction equals to that of the yoke of the primary core element;
• wherein adjacent permanent magnets have opposite excitation directions, and a horizontal component of the excitation in all permanent magnets cannot be zero, thus creating a bipolar permanent magnet magnetic field;
• wherein when a primary core element separately constitutes a primary core element group, between any two adjacent primary core elements, adjacent armature teeth, the permanent magnet and the yoke forgo slots C with the same area;
• wherein within each primary core element group, the adjacent armature teeth and the yoke form N−1 slots A, wherein 2≤N≤3, and between the adjacent two primary core element groups, the armature teeth, the permanent magnet and the yoke form a slot B, and a slot A and a slot B have the same area;
• wherein the first secondary and the second secondary are salient structures with the same teeth width, and the salient section is used as the modulation teeth;
• the first secondary and the second secondary are not completely symmetrical;
• and
• a centerline of modulation tooth of the first secondary coincides with a centerline of the slots of the second secondary, so that the teeth of the first secondary are opposite to the slots of the second secondary and a magnetic circuit on both sides can be realized in series.