Electric Power Research Institute Incorporated

Lockheed Martin Energy Research Corporation

Jack S Lawler

Patrick James McCleer

J Milton Bailey

John Milton Bailey

Natarajan Narasimhamurthi

A circuit and method for controlling a rotating machine (,) in the constant horsepower range above base speed uses an inverter (,) having SCR's (T,-T,) connected in series with the primary commutation switches (Q,-Q,) to control turn off of the primary commutation switches and to protect the primary commutation switches from faults. The primary commutation switches (Q,-Q,) are controlled by a controller (,), to fire in advance or after a time when the back emf equals the applied voltage, and then to turn off after a precise dwell time, such that suitable power is developed at speeds up to at least six times base speed.

Constant power speed range extension of surface mounted PM motors

A new class of higher phase-order (five or more) quasi square-wave back emf permanent magnet machines including radial, axial and linear embodiments which employ a greater number of active phase windings during continuous operation, thereby utilizing more of the machine copper and magnet material.

Quasi square-wave back-EMF permanent magnet AC machines with five or

A method for smoothing the torque characteristics of a multi-phase PM synchronous machine by controlled driving with a conventional voltage source inverter operated in accordance with a predetermined switching sequence wherein the sum of the excitation voltages applied to the incoming phase winding and outgoing phase winding are maintained constant at a predetermined value for the duration of each commutation period. In addition, the individual excitation voltages applied to the remaining phase active windings are also held constant during the commutation period.

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Knoxville, TN, United States of America

Jack S Lawler