Cosmin Darab

Development and application of a predictive adaptive controller to a wastewater treatment process

This paper presents an application regarding a single input single output (SISO) long range predictive adaptive controller. The Generalized Predictive Control (GPC) method uses long range prediction based on a dynamic model of the plant. The model is obtained in the adaptive context by recursive estimation. The parameter estimation algorithm, basically the recursive least square algorithm, has been modified to provide a robust parameter estimator. The proposed algorithms are used to control the biological part of a wastewater treatment process. The performances of control algorithms are illustrated by simulation results.

Modeling and internal model control strategy of pH neutralization process

This paper presents a possible application of controlling industrial pH processes using internal model control strategy. The developed strategy consists in including the neutralization model within the control structure. In this work a pH neutralization process for acetic acid and sodium hydroxide model is developed in Matlab/SIMULINK simulation environment. The proposed controller is implemented using internal model control strategy design. Process simulations and control loop validation plots are presented.

Modelling and calibration of a conventional activated sludge wastewater treatment plant

Wastewater treatment plants (WWTPs) are key infrastructures for ensuring a proper protection of the environment. Mathematical modelling and simulation of activated sludge systems have gained increasing attention in control engineering within the last years. The most widely used models to describe the biochemical processes that take place in a WWTP are the Activated Sludge Models 1-3. Due to their increased complexity, these models are often unsuited for control systems design. The aim of this paper is to develop reduced order models which can adequately describe the biochemical processes for the purpose of on-line control design. The models developed contain a minimum number of variables and parameters that allow for model identification and validation based on available on-line measurements.

Modeling of drug delivery in general anesthesia

Manual or open-loop administration does not take into account patients individual dose or dose-response relationship; hence they represent sub-optimal solutions for optimizing individual drug titration. This may lead to under-or over- sedation, increasing the time on mechanical ventilation, the length of intensive care unit (ICU) stay and mortality. Model based predictive control can mitigate with this problem, improving the efficiency of drug delivery and patient safety. A multiple-input single-output (MISO) patient model is identified and validated in this paper. The inputs are two drugs commonly used for general anesthesia, propofol and remifentanil, and the output is the Bispectral Index (BIS). Wavelet time-frequency analysis was used to filter the measured signals. The parameters of the interaction model which relates the effect-site concentrations of these drugs to BIS are identified based on least-squares algorithm, using data from real-life clinical tests.

Robust control of MPPT of a PV cell

This work presents a robust control approach for Maximum Power Point Tracking (MPPT) of a standalone solar Photo Voltaic (PV) system, in order to boost its efficiency. For testing the algorithm, it was considered an 80W stand-alone solar PV cell. In order to improve the efficiency of the charge controller, the proposed control strategy follows the maximum power point output.

An improved fuzzy slide mode control applied to PV systems

The aim of this work is to present a novel fuzzy slide mode control (FSMC) to extract a maximum power point (MPP) of the photovoltaic (PV) generator. This technique allows tracking the MPP consequently for the different operating condition of radiation and temperature. The FSMC is simulated with Matlab/Simulink environment and compared with the perturb and observe (P&O) method. The tests results confirm that the FSMC develops the performance of the PV system (PVS).

Experimental results of photovoltaic emulator systems

In this paper, we present experimental results of photovoltaic (PV) emulator systems implemented in a low-cost microcontroller. The insufficiency of space for installation of real PV panels and the high costs of the commercial emulators require of alternative systems which allow the generation of the characteristic curves of the solar panels. Irradiance and temperature can be set on the emulator to emulate the behavior of a PV panel. The implementation methodology and their effects on the PV output are performed and discussed in detail for each scheme of PV emulator system.

Photovoltaic water pumping system application in Morocco

In Morocco, the use of renewable energies present have a great importance especially with the new energy strategy. The important geographical location of the Kingdom helps for the development of the use of the solar energy. To reduce the import of primary energy, and to make face to the high demand of electricity and water in remote zone, the government has made several projects to encourage the use of a local industry in the renewable energy sector which promotes also to minimize carbon emissions. However, given to the importance of the solar irradiation intensity received and his duration, the country has the possibility to cover some of its solar energy needs. The empoyement of solar energy to pump water is one of the most used applications; this technique presents a good solution wherever the grid does not exist. In this document, we will show a presentation of photovoltaic water pumping system components, and the most important solar pumping projects installed in Morocco to supply water in remote areas.

Maximum power point tracking applied to PV systems under partial shading conditions

Characteristics of large photovoltaic (PV) panels under partially shaded conditions are characterized by multiple peaks and steps. This makes the tracking of the actual maximum power point (MPP) a difficult task. Moreover, most of the existing maximum power point tracking (MPPT) is unable to extract maximum power from the PV array under partial shading conditions. In this paper, a novel FLC method has been presented to track the global maximum power point (GMPP) of PV. The proposed technique is based on the output current of the photovoltaic system (PVS). Compared with the P&O method, The proposed FLC method can quickly find GMPP and avoid much energy loss due to blind scan. The Simulation results demonstrate an average 13% improvement in efficiency when compared with the P&O method.

Modeling and validation of nonlinear time-varying pH industrial processes

This paper presents an approach on the modeling and validation of nonlinear pH process, it uses the chemical balance equations of an industrial neutralization process between acetic acid and sodium hydroxide. This study develops a simple solution for the process model. The model obtained is validated and shows that is capable of capturing both the nonlinearities and the time-varying characteristics of the pH process.