XI International Symposium on Industrial Electronics - INDEL 2016
3-5 November 2016, Banja Luka, Bosnia and Herzegovina

The Symposium is sponsored by IEEE Industrial Electronics Society and IEEE Power Electronics Society

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Invited Papers

On the Importance of Electromagnetic Models in RFIC Design

Dušan N. Grujić, Pavle Jovanović, Milan Savić, Lazar Saranovac

In low frequency analog or digital design designers are mainly concerned about parasitic resistance and capacitance, while neglecting inductive and propagation effects. The designs are complex, both in terms of number of transistors and interconnect lines. To cope with this complexity, tools for parasitic extraction use precomputed capacitance tables and employ pattern matching algorithms. Pattern matching approach results in reasonable run time and accuracy better than 10%, which is acceptable for most low frequency designs. In contrast, high frequency RFIC designs have much smaller number of transistors and simpler interconnect, but require higher accuracy and modeling of inductive, skin and possibly propagation effects. In this paper we will discuss some of the problems and possible solutions for proper simulation of RF circuits and the importance of electromagnetic models. Conclusions will be demonstrated on the example of modeling the integrated voltage controlled oscillator.

Important Changes in Electrical Industry

Slobodan N. Vukosavić

The sources in traditional electric power system are wound-field synchronous generators. Their power - frequency - power angle characteristic represents the key aspect of the control and stability of the system. In cases with short circuits along the grid, traditional generators supply the fault location with their characteristic sub-transient and transient short circuit currents. The capability of supplying the proper short circuit current is prerequisite for achieving a properly selective and coordinated protection system. The advent of HVDC transmission, renewables, microgrids and dc-current distribution systems, a number of controlled power sources is introduced into the grid, with the behavior quite unlike the traditional generators. Solar plants and wind power farms are connected to the grid by means of 3-phase grid-side converters, which supply ac currents in order to achieve the desired active and reactive power. Moreover, the new electric loads are also interfaced through 3-phase or single-phase electronically controlled power converters.

The static power converters with electronic control of grid-injected currents and power may introduce small, parasitic dc currents into the grid, jeopardizing in this way the operation of power transformers. At the same time, static power converters are frequently the source of line harmonics that have adverse effect on the power quality. With electronic power control, the grid-side converters tend to reduce the current on occasions when the grid voltage rises. Their behavioral model includes negative resistance, thus reducing the stability margin of the power system. Moreover, the converters lack the desired power-frequency-angle relation of synchronous generators.

The above mentioned problems increase with the percentage of electronically controlled sources and loads connected to the system. At the present state, installed capacity of solar and wind power plants reaches 10% and 18%, respectively. For these reasons, it is necessary to develop and deploy the control and protection mechanisms that would resolved compatibility issues that arise in ac grids with large amounts of electronically controlled sources and loads.

Limits to Optical Chemical Sensing: Fluctuations Versus Ultimate Performance

Zoran Jakšić, Olga Jakšić

The role of chemical sensing in modern process industry cannot be overestimated, since they are encountered at different stages of process control, helping maintain product quality and at the same time keeping an eye on environmental issues and pollution problems. Numerous device families are currently in use, where optical chemical sensors are probably the fastest, the simplest and the most sensitive. Affinity sensors represent a class of these devices based on adsorption of chemical analytes. The prime example of these are plasmonic sensors, which are label-free, ultrasensitive and ultrafast. Literature usually defines only the ideal sensitivity of such devices and their performance is taken as granted. In reality there are many parasitic processes that decrease their performance and introduce significant measurement uncertainties. Noise and fluctuations in such sensors can be generated by both extrinsic or intrinsic sources and a significant part of them is a consequence of fundamental processes that at the same time ensure the very function of the devices. The main intrinsic mechanisms include adsorption-desorption, optical flicker and thermal noise, while the level of the extrinsic noise is related with the quality of the interrogating beam source and the photodetector. In this contribution we offer a possible systematization of different sources of noise in refractometric chemical sensors and analyze the influence of such fluctuations to the ultimate device performance.