Showing papers on "Variable-frequency drive published in 1991"
15 Apr 1991
TL;DR: In this article, a vector-controlled AC variable frequency drive was used to process rubber compounds in an internal mixer, which was applied to a common industrial process with a 1500hp, 2300 volt, current-fed inverter.
Abstract: The mechanism of processing rubber compounds in an internal mixer creates a tough, demanding application for which a vector-controlled AC variable frequency drive was found to be eminently suitable A 1500 hp, 2300 volt, current-fed inverter was successfully applied to this common industrial process A description is presented of the control strategy, drive construction and operation, and application considerations Operating results are discussed >
2 citations
Patent•
31 Jan 1991
TL;DR: In this article, a control means is provided to connect an induction motor 3 to a commercial power source 1 only for a specified time from a power supply interruption point in driving the motor in a constant frequency by full voltage starting after the elapse of the specified time.
Abstract: PURPOSE:To allow an induction motor surely to switch full voltage starting over to an inverter always in a short time by providing a means to apply the voltage from a commercial power source for the reexciting in residual voltage extinction of a motor when the drive is shifted from full voltage starting to the inverter. CONSTITUTION:A control means is provided to connect an induction motor 3 to a commercial power source 1 only for a specified time from a power supply interruption point in driving the motor in a constant frequency by full voltage starting after the elapse of a specified time. In compliance with the power connection by this control means the operation of an inverter 2 in a specified frequency is started by the residual voltage generated from an induction motor 3 and the operation is to be shifted to the variable frequency drive by the inverter 2. The switching of full voltage starting over to the inverter 2 can thereby be performed within a pretty short time regardless of the rotation inertia quantity of a motor load, making the most of the merit to reduced the inverter capacity by switching the full voltage starting over to the output of the inverter 2.
1 citations
29 May 1991
TL;DR: In this article, the development of a 5 hp prototype solid state phase converter has been completed, which is capable of handling a power level equal to the entire service capacity of a standard rural feed.
Abstract: The development of the 5 hp prototype solid state phase converter has been completed. The converter will fill a need for motor drives which require more control than the present phase converters can provide but do not require a full-blown variable frequency drive. While a variable frequency drive can operate a three phase motor from a single phase supply, it does not typically provide power factor correction as the solid state phase converter does. The technology developed is capable of handling a power level equal to the entire service capacity of a standard rural feed. >