Sundstrand Corporation

Robert G Glass

Waleed M Said

John F Defenbaugh

Eric Alan Henderson

Clive M Danby

Peter D Waters

A control for an inverter system having first and second inverters that produce inverter outputs wherein the inverter outputs are combined by an interphase transformer (IPT) to produce an AC output includes circuitry for detecting a magnitude of a harmonic component in the AC output waveform and circuitry for developing first and second PWM control waveforms for controlling the first and second inverters, respectively. The second PWM control waveform is phase delayed relative to the first PWM control waveform to in turn regulate the magnitude of the harmonic component and DC content across the IPT is controlled to prevent damage to the IPT.

Adaptive harmonic distortion control for parallel connected inverters

A simulator (100) of an electrical power generating system in accordance with the invention includes a programmed electrical power system simulator (104) specifying at least one simulated electrical power generating element (200) for generating electrical power and at least one simulated contactor (202, 206, 210, 212 and 216) for connecting the at least one simulated electrical power generating element to at least one simulated load bus (208), a state of the simulated elements of the simulated electrical power generating system during simulated generation of electrical power and a simulated state of elements of the electrical power generating system in response to a simulated fault condition; an input (102) for inputting data to the programmed simulator relating to the simulated operation of the electrical power generating system; and an output (106) for outputting data from the programmed simulator including a display for displaying data outputted from the programmed simulator relating to simulated operation of the electrical power generating system.

Expert electrical power simulator

A refrigeration system which may be operated to control superheat at an inlet to a compressor (12) to produce a controlled superheat or to control a temperature of a fluid cooled by at least one evaporator (68) to provide the cooled fluid at a set temperature by controlling an opening of at least one expansion valve (62) in accordance with the invention includes a temperature control (206) which is activable to control the at least one expansion valve to cool the fluid to a set temperature in response to an enabling signal; a superheat control (208) which is activable to control the at least one expansion valve to control the superheat at the inlet of the compressor in response to an enabling signal; and a controller (204) responsive to the at least one logic operational state of the refrigeration system, for generating one of the enabling signals to activate one of the temperature control or the superheat control to control the at least one expansion valve to control superheat or provide cooled fluid at the set temperature.

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Loves Park, IL, United States of America

Robert G Glass