SINGLE-PHASE POLE-CHANGING MOTOR WINDING (DESIGN VERSIONS) Russian patent published in 2000 - IPC

FIELD: electrical engineering. SUBSTANCE: single-layer windings have K coil groups 1-12 with coil number in coil groups greater than or equal to unity. Winding pitch equals pole pitch τ₂ depending on number of pole pairs P₂. Each proposed winding is sectionalized at each pole pair P₁= P₂/2; first and second coil groups are arranged on each pole pair P₂. Pole pair P₁ is obtained due to cumulative connection of coils of first and second parts of winding. Coil groups also form pole pair P₃ its first phase being formed by odd-numbered coil groups and second phase, by even- numbered ones; each next coil group in each phase is differentially connected to preceding one. Each of two phases of winding is built up of sections of four types connected in series at pole pairs P₁ and P₂ by means of switches, say, normally closed ones and at pole pair P₃, by, say, normally open switches. Here, type of sections and, hence, phase point of their connection is specified by coil group indexing rules. Proposed windings provide for stepped speed control of revolving magnetic field built up due to them by changing pole pairs from P₁ and P₂ to P₃. Changing pole pairs is effected by current reversal in sections of second and third types while those of third and fourth types are changed over from one phase to other. Proposed winding connection circuits used for motor switching-over to single-phase supply using capacitor banks enable alternation of winding phases and their connection in series or in parallel. EFFECT: reduced number of phase leads which facilitates coil manufacture; reduced capital outlays and improved reliability of winding. 6 cl, 6 dwg