Sundstrand Corporation

William J Peterson

Timothy F Glennon

James B Thom

Dennis T Faulkner

Richard P Ejzak

This invention relates to a motor control system for a brushless DC motor having an inverter responsively coupled to the motor control system and in power transmitting relationship to the motor. The motor control system includes a motor rotor speed detecting unit that provides a pulsed waveform signal proportional to rotor speed. This pulsed waveform signal is delivered to the inverter to thereby cause an inverter fundamental current waveform output to the motor to be switched at a rate proportional to said rotor speed. In addition, the fundamental current waveform is also pulse width modulated at a rate proportional to the rotor speed. A fundamental current waveform phase advance circuit is controllingly coupled to the inverter. The phase advance circuit is coupled to receive the pulsed waveform signal from the motor rotor speed detecting unit and phase advance the pulsed waveform signal as a predetermined function of motor speed to thereby cause the fundamental current waveform to be advanced and thereby compensate for fundamental current waveform lag due to motor winding reactance which allows the motor to operate at higher speeds than the motor is rated while providing optimal torque and therefore increased efficiency.

Motor control for a brushless DC motor

A motor driven generator has a generator control unit which incorporates a programmed microprocessor to control generator operation. A generator voltage regulator utilizes the microprocessor of the generator control unit to develop an error voltage which is added to the average phase voltage of the generator, controlling the generator field current. In the event of a phase failure the generator control unit senses an abnormally high phase voltage condition, disables the average phase voltage circuit. In the event of an abnormal difference between the high and low phase voltages, the gain of the error signal circuit is reduced.

Voltage regulator

A control for an electrical generating and distribution system utilizing a plurality of interconnected microprocessors. An electrical system, for an aircraft for example, may have two engine driven generators and an auxiliary power unit generator with loads connected to each of the engine driven generators through generator circuit breakers. An electrical distribution bus connected through bus tie breakers interconnects the load circuits and the auxiliary generator so that any one generator can power either or both loads. Each generator has a microprocessor generator control unit responsive to the associated generator conditions to control generator operation. A microprocessor bus power control unit is responsive to distribution circuit conditions and correlates information from the generator control units, contributing to operation of the bus tie breakers, controlling distribution of power from the generators to the loads. Serial data links between the bus power control unit and each of the generator control units provide for communication of input and control information and enable comparison of redundant circuit information enhancing reliability of the system operation. A generator voltage regulator utilizes the microprocessor of the generator control unit to develop an error voltage which is added to the average phase voltage of the generator, controlling the generator field current. In the event of a phase failure the generator control unit senses an abnormally high phase voltage condition, disables the average phase voltage circuit and the regulator continues to operate with the error voltage.

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Rockford, IL, United States of America

William J Peterson