The effect of pulse linear electromagnetic motors on voltage fluctuations in electric power networks of an industrial enterprise

Abstract

Pulsing power consumption from the electric networks of industrial enterprises causing inadmissible voltage oscillations is a feature of linear electromagnetic motors in the drives of shock machines. Studies in this area are important because of the need to find the ranges of admissible parameters of an electric network and pulse linear electric motor when it is fed via a three-phase bridge rectifier to provide an admissible level of power network voltage variation. Based on a diagram, at the moment when the electric motor is turned on and is fed via the bridge rectifier, an expression for phase current was obtained that was expanded into Fourier series within the first period of industrial frequency considering fundamental harmonics. Based on expressions of the first harmonic of the current and surges of reactive and active power consumed from the network within the first period, relationships between the parameters of the supplying network and electric motor are obtained. Ranges of admissible values of these parameters satisfying the level of measurement of voltage of the electric network equal to 5% are determined. Outside the regions of admissible variations of voltage, it is required to use an intermediate energy accumulator or design of the electromagnetic motor should include a device for anchor retaining. Using the example of calculation of five three-phase oil transformers of typical sizes, the boundaries and ranges of admissible variation of parameters of pulse electromagnetic motors when those supplied by a three-phase power supply via bridge rectifier.