Power Current Control of a Resonant Vibratory Conveyor Having Electromagnetic Drive

Abstract

Technical Faculty "Mihajlo Pupin" Zrenjanin, University of the Novi Sad, Novi Sad, SerbiaThe vibratory conveyors with electromagnetic drive are used for performing gravimetric flow of granular materials in processing industry. By realizing free vibrations of variable intensity and frequency over a wide range through application of the electromagnetic actuator, suitable power converter, and the corresponding controller, continuous conveyance of granular materials have been provided for various operating conditions. Standard power output stages intended for control of vibratory conveyance using thyristors and triacs. Phase angle control can only accomplish tuning of amplitude oscillations, but oscillation frequency cannot be adjusted by these converters. Application of current controlled transistor converters enables accomplishing the amplitude and/or frequency control. Their use implies the excitation of a vibratory conveyor independent of the supply network frequency. In addition, the frequency control ensures operation in the region of mechanical resonance. Operation in this region is favourable from the energy point of view, since it requires minimal energy consumption. The paper presents a possible solution and advantages of the amplitude-frequency control of vibratory conveyors by means of a current controlled power converter.

Hardware and Software Implementations of Measuring System for Resonant Electromagnetic Vibratory Conveyor

“…However, there is a relationship between the force and the current of the electromagnetic actuator [4,12,[32][33][34][35][36], thus measurement of electrical current is important in these applications. A certain care should be taken into account while operating with the electromagnetic actuator regarding high voltage supplied from the power converter.…”

“…1. Control signal of REVC is provided from controllable AC/DC power converter [4,[12][13][14][15][16][17]19], which is connected on power grid network of 230V, 50Hz.…”

“…The standard power output stages of REVC using SCR devices (thyristors and triacs) [4], [9][10][11][12]. This implies using the phase angle control (PAC) and constant frequency of vibration.…”

“…PAC can only accomplish tuning amplitude of vibration, but not the oscillatory frequency. Application of switch mode power converters (IGBT or MOSFET) enables accomplishing the amplitude and (or) frequency control of REVC [4,12,[13][14][15][16][17][18][19][20]. Their use implies the excitation of an REVC independent of the mains frequency.…”

Vibration control of resonant vibratory feeders with electromagnetic excitation

“…Since the supply network frequency is constant (50Hz/60Hz), the adjusting of phase angle can only accomplished control of the amplitude oscillations, but not and their frequency [6][7], [9]. Application of switch mode IGBT power converters enables accomplishing the amplitude and/or frequency control of EMVF [11][12][13]. Their use makes the excitation of EMVF independent of the supply network frequency.…”