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Methods for Calculation of the Variable Parameters of a Rotor of the Cage Induction Motor
No full textExploitation of squirrel-cage induction motors (SCIMs) is inevitably accompanied by the appearance of the transient processes that critically impact the condition and operation of electrical machines. In the study of transients in induction motors must consider that during the start-up, the rotor parameters (resistance and inductance) are changing due to the skin effect. The current paper is dedicated to the research of the direct start-up of the SCIM with due account for of the current’s displacement in the rotor slots. The current paper is dedicated to the research of the different methods for calculations the rotor’s variables parameters.
The resistance and inductance of the rotor were calculated in different methods. The conclusion about the need to consider the skin effect in the calculations of the rotor’s variables parameters is given
On Factors of Development of Knowledge Based Innovation Enterprise
No full textInnovation is the introduction of new ideas, goods, services, and practices which are intended to be useful. The main driver for innovation is often the courage and energy to better the world. An essential element for innovation is its application in a commercially successful way
Possibilities of Realization of AC Transistors
No full textAn article deals with possibility of realization of AC transistor, which can conduct controlled current in the both directions. Are proposed possible scheme of realization and given a static characteristics described by suggested equations
Bezkontaktu elektrisko mašīnu pētījumiem – 50
No full textLatvijā bezkontaktu elektrisko mašīnu pētījumiem ir turpat 50 gadus ilga vēsture, un ir vesela zinātnieku plejāde, kuri devuši ievērojamu ieguldījumu bezkontaktu elektrisko mašīnu teorijā un prkatiskajā izmantošanā
A Multipolar Directly-Driven Inductor Generator for Windmills
No full textA design of the unductor generator for 12-kW windmills is considered, with the rotation speed of 100min-1, directly driven from a wind turbine without a step-up multiplier. The generator is ring-wise, with an increase ratio of bore diameter D to the core lightened non-magnetic sleeve. The mass of the generator is 280 kg, its efficiency - 86%. The paper presents a mathematical model developed for generators of the kind
Some Theoretical Aspects and Principles of Design a Multipole Asynchronous Machine with Mutually Immovable Windings
No full textThe paper considers a multipole asynchronous machines in which multiphase primary and secondary windings are arranged on the stator mutually immovablly. The rotor presents a tooth-like magnetic system with the pole pair number equal to the number of teeth. The generalised equations obtained for the such asynchronous machines convenient asynchronous generators and motors
Analysis of the Direct Frequency Conversion Process in the Rectifier Mode
No full textIn the paper, the rectifier mode of the direct frequency conversion process is considered both for the ideal sinusoidal process and for a real one. Based on the analysis and estimation of these processes, some conversion methods are proposed, which are designed for improving the quality of converter output voltage
A Novel Approach to Control Direct Frequency Converter in A.C.Drive
No full textA new approach to real approximation of an ideal sinusoidal frequency conversion process is put forward in the present paper. This enables the output frequency range of line-commutated direct frequency converters to be expanded up to the value of input frequency. This is achieved by the application of a low frequency value sinusoidal modulating function and the substitution of input voltage and modulating function product with approaching to it input voltage level intervals. An example of this frequency conversion in terms of the simplest six thyristor circuit is considered for a fan drive
