Abstract: A power conversion system is described which includes a power input for accepting a waveform at a given power level and frequency, and a power output for providing an output waveform at a second given power level. A DC to AC converter accepts a waveform based on an input wave form from the power input and converts the waveform to an AC waveform having a frequency at least approximately an order of magnatude higher than the frequency of the input waveform for application to a DC to AC converter output. An AC converter accepts the output waveform from the DC to AC converter output and provides a converted waveform from an output of the AC converter to the power output. A coupling device operates at the frequency of the converter output for coupling the output of the DC to AC converter to the AC converter.

Abstract: The present invention locates the primary winding of a transformer in a configuration where it substantially surrounds the secondary winding of the transformer in order to enhance the efficiency of the electromagnetic coupling. High magnetic permeability material surrounds portions of the primary winding of the transformer. The transformer is designed to efficiently operate at frequencies of approximately 50 kilohertz. In one preferred embodiment, the primary winding of the invention is formed of two U-shapes in which the parallel members of the U are substantially longer than the bottom portion of the U. The two U-shapes form a rectangular shape and the substantially parallel rectangular portions are surrounded by high magnetic permeability material to further enhance the electromagnetic coupling between the primary coil winding and the secondary coil winding. In another embodiment, the primary winding of the invention may be rectangular in shape.

Abstract: The present invention locates the primary winding of a transformer in a configuration where it substantially surrounds the secondary winding of the transformer in order to enhance the efficiency of the electromagnetic coupling. High magnetic permeability material surrounds portions of the primary winding of the transformer. The transformer is designed to efficiently operate at frequencies of approximately 50 kilohertz. In one preferred embodiment, the primary winding of the invention is formed of two U-shapes in which the parallel members of the U are substantially longer than the bottom portion of the U. The two U-shapes form a rectangular shape and the substantially parallel rectangular portions are surrounded by high magnetic permeability material to further enhance the electromagnetic coupling between the primary coil winding and the secondary coil winding. In another embodiment, the primary winding of the invention may be rectangular in shape.

Abstract: The present invention converts an alternating current input into a direct current output by switching a current load at high speeds to create a voltage envelope having a maximum allowed voltage and a minimum allowed voltage. Complementary switching elements are employed to take advantage of both the positive and negative portions of an AC cycle. Load switching is arranged so that the current vector which represents the load is nearly coincident with the voltage vector which represents the power source. The system can operate in an open loop mode at a constant frequency, in a closed loop mode, or in a hysteresis mode. During open loop operation, the voltage envelope is not rigidly defined as the switching frequency remains constant. During hysteresis mode control, the voltage envelope remains fixed and the current switching frequency varies.

Abstract: A pulse width modulation DC to DC converter operates in an open loop mode to convert the DC output of the AC to DC converter to a desired, predetermined DC level using pulse width modulation techniques and a switching configuration substantially similar to that of the AC to DC converter.

Abstract: A control system for poly-phase power inverters that uses feedback sensed voltages and currents to control the switching of solid state power switches in the inverter bridges, producing a nearly ideal sinewave voltage output regardless of load induced or switching harmonic voltages. The system operates in combination with the inverter power switches and switch drivers, particularly incorporating a digital programed optimal controller with virtually no delay in implementing the feedback control, and automatically correcting for any sensed line voltage distortions. The system inherently provides a high recovery speed for voltage transients.

Abstract: A method is described for controlling synchronous motor torque, utilizing a three-phase switch connected in a circuit to the input of a polyphase synchronous motor, and a switch control circuit. The switch control circuit senses the AC voltages input to the synchronous motor and produces signals that open and close the three-phase switch in phase with the input motor voltage, producing positive motor torque during normal operation. If input AC power is lost, the switch control circuit acts to prevent a reverse flow of high current from the motor from entering the power source bus. When input power, after a short time, returns, the switch control circuit acts to close the three-phase switch in such a manner as to permit only real power applied to the synchronous motor and thus positive torque that accelerates the motor speed and quickly restores the motor to synchronism with the input power source.

Abstract: An output frequency control circuit is mounted on the rotating shaft connecting a motor and generator. The motor-generator system includes exciter circuits, an input power factor control and an output voltage regulator. The input power factor control ensures that the motor input power factor is unity, which is desirable for motor control. The frequency control circuit responds to variations in the AC power source frequency by generating low frequency excitation to boost or buck the operational speed of the machine, causing the generator output frequency to remain constant at a selected frequency output irrespective of input power source frequency variation. The output frequency may be selected over a given range from a control panel adjustment pot.The major innovation is that the entire frequency control circuit is shaft-mounted and requires no slip-rings or magnetic transformers for signal transfer, thus reducing the possibilities of mechanical failure.