Electricity: motive power systems – Induction motor systems – Primary circuit control
Patent
1985-04-02
1986-07-08
Smith, Jr., David
Electricity: motive power systems
Induction motor systems
Primary circuit control
318798, 318806, H02P 540
Patent
active
045995508
ABSTRACT:
Programmed digital equipment is utilized to generate three-phase pulse width modulated waveforms that are used in controlling an induction motor. A microprocessor is programmed to initialize conditions in the system, to perform a main task including the storage of converted analog signal, the checking of limits of motor motion and information fed back from the motor concernings its position, and the ramping of frequencies to change the position of the motor. A memory is provided for the programming which memory also contains tables that correspond to 90.degree. of each desired wave form. A single 90.degree. segment of each wave form is needed to generate all parts of each of the three phases. An analog to digital converter is utilized to convert analog information concerning gain, set point, dead band and feedback signal into digital signals which are stored and processed by the microprocessor. Programmable timers are connected to the microprocessors for generating the wave forms and for supplying master timing and interrupt signals indicative of an undesirable condition in the motor control.
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Robertson, Jr. John W.
Siegel Stuart B.
Edwards Robert J.
Matas Vytas R.
Smith Jr. David
The Babcock & Wilcox Company
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