Abstract: The intra-grid power director comprises a polyphase electric machine having a rotor that can be turned through less than a complete revolution within a stator winding. The rotor winding is connected within a transmission line to a first portion of an electric utility power grid, all portions of which operate at the same frequency. The stator winding is connected to the other portion of the grid so as to generate a rotating magnetic field having the same direction of rotation as the field generated by the rotor winding. The power director also comprises an arrangement for selecting an angular relationship between the stator and rotor windings and for sustaining a resultant torque.

Abstract: A rotating field transformer comprises a torque motor and a rotating electric machine having two sets of windings, each of the windings connected to a respective polyphase electric circuit. The two windings have the same number of magnetic poles and generate coincident rotating magnetic fields having the same direction of rotation. When a torque is applied (e.g., to the shaft of a rotor carrying one of the windings) in the same direction as that of the rotating magnetic fields, electric power is transferred from the rotor-connected circuit to the stator-connected circuit. The rotating field transformer can be used to control the frequency at which power is supplied to a polyphase load, or to manage instabilities in weak links between generating stations.

Abstract: The present invention provides smooth conversion of electric power between an AC line operating at a first voltage and a DC line operating at a second voltage bearing a fixed ratio to the first voltage. In one embodiment, polyphase AC is converted to rippled DC. In one embodiment, switched DC is converted to AC of one or more phases. The electric power converter of the invention uses a single electrical winding can be thought of as derived from the formerly well-known, and now largely forgotten, synchronous converter by locking the rotor, discarding the field winding and its power supply, replacing the AC slip ring contacts with hardwired connections, and replacing the DC commutator taps, bars and brushes with rectifying taps. Thus, the new power converter may be referred to as a single-winding static synchronous converter.

Abstract: Electric power converter with load compensation, especially for electrical loads subject to fluctuations in demand for power, such as arc furnaces, welders, etc. An external source of electrical power is applied to a stationary input winding of the converter to produce a movable polyphase magnetic field coupled to an output winding movable at least in part over a limited range relative to the input winding. The movement is resisted by an interposed resilient member adapted to position the output winding to match the output to the input power demand of the load equipment thereby counteracting whatever fluctuations tend to occur in load resistance and current.

Abstract: An asynchronous converter comprises a torque motor and a rotating electric machine having two sets of windings, each of the windings connected to a respective polyphase electric circuit. The two windings have the same number of magnetic poles and generate coincident rotating magnetic fields having the same direction of rotation. When a torque is applied (e.g., to the shaft of a rotor carrying one of the windings) in the same direction as that of the rotating magnetic fields, electric power is transferred from the rotor-connected circuit to the stator-connected circuit. When the direction of the torque is reversed, the direction of the power transfer is also reversed. The two polyphase circuits may differ in voltage, in frequency and in number of electrical phases, but it is expected that in most cases the number of phases will be equal to three for both circuits and the operating frequencies of the two circuits will differ by no more than a few percent.

Abstract: An apparatus and method for inverting direct current electrical power into alternating current electrical power by producing a moving magnetic field having substantially constant flux density when the direct current power is applied to a primary winding, magnetically coupling a secondary winding to the moving magnetic field and creating a substantially triangular-shaped current in each phase of the primary winding so as to produce substantially sinusoidal alternating current in each phase of the secondary winding.

Abstract: An electric power converter operable by means of a rotating or moving magnetic field having a substantially constant flux density or of a substantially constant magnitude. The electric power converter functions as a AC to DC, DC to AC or DC converter, or as a phase changer/phase shifter or a voltage adjuster. A feature of the converter is the continuous supply of power from the primary phases in contrast to prior art converters in which only the phase having the highest voltage supplies power at any one time. Harmonic current distortion is, therefore, substantially reduced.