In this paper, a high-performance feedback controller for an electromagnetic vibratory feeder is proposed. An electromagnetic actuator is driven by a switching circuit with pulsewidth as the control variable. The controller structure consists of a proportional-integral controller combined with a state observer. The controlled variable is the resonant frequency vibration amplitude obtained in real time from the state observer. The use of the state observer allows fast disturbance rejection and reference tracking in both directions (amplitude increase and decrease). Simulations and experimental results from the real device are presented.

A mathematical model of two-mass vibratory conveying system with electromagnetic vibratory actuator (EVA) and possible ways of their optimal control by using power converter is presented in this paper. Vibratory conveyors are commonly used in industry to carry a wide variety of particulate and granular materials. Application of electromagnetic vibratory drive combined with power converters provides flexibility during work. The use of a silicon-controlled rectifier (SCR) implies a phase angle control, which is very easy, but with many disadvantages (fixed frequency which is imposed by ac mains supply, poor power factor, mechanical retuning, etc.). Switching converters overcomes these disadvantages. Only then, driving for EVA does not depend on mains frequency. As well as amplitude and duration of excitation force tuning, it is also possible to tune its frequency. Consequently, complicated mechanical tuning is eliminated and seeking resonant frequency is provided. Previously mentioned facts motivated phase angle control and switch mode control behavior research for electromagnetic vibratory drives. Simulation and experimental results and their comparisons are exposed in this paper. The simulation model and results are given in the program package PSPICE. Experimental results are recorded on implemented control systems for SCR and transistor power converters. Partial results concerning the resonant frequency seeking process with transistor converter are also exposed

The vibratory feeders with electromagnetic excitation called electromagnetic vibratory feeders (EMVF) are commonly used for performing gravimetric flow of granular and particulate materials in processing industry. This drives offer easy and simple control the mass flow of conveying materials. In comparison with other drives (pneumatics, inertial, centrifugal, etc...), these have a more simple construction and they are compact, robust and reliable in operation. The absence of wearing mechanical part, such as gears, cams belts, bearings, eccentrics, etc., makes EMVF, most economical equipment. Standard power electronic output stages intended for control of the EMVF using SCR devices (thyristors and triacs). This implies phase angle control (PAC) and constant frequency of vibration. In this way control circuit must be synchronized to the mains supply frequency 50(60) Hz. PAC can only accomplish tuning amplitude of vibration, but not vibratory frequency. Application of transistor (IGBT or MOSFET) switch mode power converters enables accomplishing the amplitude and (or) frequency control of EMVF. Their use implies the excitation of an EMVF independent of the mains supply frequency. In addition, the frequency control ensures operation in the region of mechanical resonance. This operation is highly efficient, because large output displacement is provided by small input power. An optimal and efficient operation requires tracking of resonant frequency. This paper presents possible solution of the amplitude frequency control of EMVF and corresponding simulation and experimental results.

Perturb & Observe (P&O) and Incremental Conductance (IC) maximum power point tracking (MPPT) methods are presented in this paper. Algorithms of these methods are implemented in a control of PV-fed single-ended primary inductance converter (SEPIC). These algorithms determine duty cycle of pulse width modulation (PWM) of SEPIC, to control operation point of the system. After application of those methods, the power measurements are compared to the power measurements for various values of duty cycle, i.e. SEPIC is in open loop, in order to determine efficiency of those methods.