초록 ▼

In a polyphase machine, being either a motor or a generator, there is provided a stator core having main stator windings wound about the stator core and main windings having a capacitor connected in series with each winding of the core. Switches are provided for each winding, and a trigger source fo

In a polyphase machine, being either a motor or a generator, there is provided a stator core having main stator windings wound about the stator core and main windings having a capacitor connected in series with each winding of the core. Switches are provided for each winding, and a trigger source for the switches operates with the capacitor and windings to ensure sequential current flow in opposite directions across the windings. Variable frequency pulses from a trigger results in a variable speed machine. With control windings wound on the stator, oppositely to the main windings there are currents in each phase which are substantially in-phase at no load with the currents of the corresponding radially adjacent the main windings. Such currents become out of phase with their main winding currents as the load increases. At low load the net flux density is low and as the load increases the flux density increases. With the centers of the poles of the control windings placed as close as physically possible between the poles of the main windings, the magnetic centering of the poles is improved. The voltage across the capacitor added to the input voltage may cause the stator core to switch periodically between non-saturated and saturated conditions.

대표청구항 ▼

A polyphase electric motor comprising: a stator including a core of magnetic material; a rotor; a main polyphase stator winding having a winding for each phase wound on said core and encompassing said magnetic material; a plurality of input terminals adapted to be connected to a voltage source; a pl

A polyphase electric motor comprising: a stator including a core of magnetic material; a rotor; a main polyphase stator winding having a winding for each phase wound on said core and encompassing said magnetic material; a plurality of input terminals adapted to be connected to a voltage source; a plurality of capacitors; means connecting the main windings of each phase in a series circuit with one of said capacitors and said series circuits being connected with said input terminals; a polyphase control winding having a winding for each phase wound on said core to encompass said magnetic material and connected respectively to said plurality of input terminals together with said main windings of each respective phase and the series connected capacitances in said series circuit, windings of the main winding being wound on the core radially adjacent to windings of the control winding; switch means for each winding of said main polyphase stator winding; and a trigger source for the switch means, the switch means being operative with the trigger source and the capacitor and each winding of said main polyphase winding to permit, on substantially low load, current flow in opposite directions across the radially adjacent windings of the main winding and the control winding, and such current flow becoming increasingly in the same direction as the load increases towards full load, the trigger source being operable at variable frequencies thereby to vary the motor speed.