- TITLE:
PARALLEL OPERATION OF CONVERTERS FOR INDUCTION HEATING
- AUTHOR(S):
T. Hristov, D. Arnaudov, S. Denchev
- ABSTRACT:
This article presents an induction heating converter simulation and parametrization. The
observed converter is used for induction hardening of different details. It consists of two equal units,
supplying power to a common load. Converters’ system simulations are performed by using as a load
a system inductor-details with certain dimensions. As a result from the simulations the requirements
to the converter control system are defined. Driving the converters according to these requirements
will help achieving constant power in the load during the heating process. Load parameters are a
function of the heated detail’s layer temperature.
- TITLE:
TIME AND FREQUENCY ANALYZES OF A FREQUENCY LOCKED LOOP
- AUTHOR(S):
Đ. Perišić, M. Bojović, A. Žorić, Ž. Gavrić
- ABSTRACT:
Unlike the Phase Locked Loops (PLL) based on the Time Recursive Processing, this paper
describes one model of Frequency Locked Loop (FLL), which is based on the Time Nonrecursive
Processing of the input periods. FLL represents linear discrete system, which is described by
two difference equations. All analyzes in time domain are performed using Z transform
approach. The analyzes in frequency domain are performed by matlab tools which are
dedicated to design and application of digital filters. It was shown that FLL is very
powerful in the tracking and predicting applications. In this paper, special attention was
devoted to finding ways to use the powerful matlab tools in the analysis of FLL. The simulation of
FLL functioning proofed the correctness of the mathematical analyzes. The realization of FLL was
described. The oscilloscope picture, made on the realized model, is presented.
- TITLE:
PRACTICAL ASPECTS OF USING VIRTUALIZATION WITH RASPBERRY PI CLUSTERS
- AUTHOR(S):
D. Vujičić, D. Mitrović, D. Marković, M. Vesković, S. Ranđić
- ABSTRACT:
In this paper we demonstrated the Raspberry Pi cluster consisted of four units. They are
interconnected and can be accessed as a singe unit from the outside world. This has been made
possible by connecting the cluster to the Internet, and having the working connection to accept the
user requests. With the simple use case scenario, we have demonstrated the practical usage of
Raspberry Pi cluster.
- TITLE:
MODEL BASED CONTROL PERFORMANCE ASSESSMENT APPLIED TO LABORATORY THERMAL PLANT
- AUTHOR(S):
A. Micić, A. Žorić
- ABSTRACT:
Fast and efficient Control Performance Assessment (CPA) presented here was performed in
three steps. Model Gm(s), represent the dynamic of the process, such that the set-point and load
disturbance responses of the evaluated controller in the loop with Gm(s) and with the same controller
in the loop with the process analyzed are in a very good agreement. The controller in the evaluated
loop, with model Gm(s), was retuned/redesigned by using the controller optimization design method
based on the frequency response Gm (iω) under constraints on the desired: sensitivity to measurement
noise Mn, maximum sensitivity M s and maximum complementary sensitivity Mp. Applying the unit
load step disturbance, comparing the Integrated Absolute Error (IAE), the maximum deviation emax
of the controlled variable, the Ms , M p and M n obtained by the evaluated controller in the loop with
Gm(s), give us valuable information how far we are from an optimum solution and search new
controller as the candidate for the calculation and implementation. Proposed method for CPA is
illustrated by simulation of thermal plant model, with the band-limited white noise added to the
controlled variable, and on a laboratory thermal plant with noise measurements.
- TITLE:
INVESTIGATION OF MULTIPHASE MODULAR TOPOLOGY FOR ENERGY STORAGE SYSTEM
- AUTHOR(S):
D. Arnaudov, S. Vuchev
- ABSTRACT:
The paper presents a modular system for charging of energy storage elements. Characteristics of
the topology are obtained for variation of different circuit components values. In accordance with the
obtained results from the parametric analyses, recommendations for the choice of components for
the individual modules are discussed. The system operability with fault condition in one of the
modules is investigated. Options for simultaneous operation of the modules to a common load are
presented. The use of synchronous converters for efficiency optimization purposes is examined.
