Bond graph modeling and robust control of a photovoltaic generator that powered an induction motor pump via SEPIC converter

Abstract

Summary Currently, the majority of economic activities depend on energy management and water management. We note, in the case of Tunisia, that the quantities of water have changed a little during the last 10 years, and the use of energies renewable energy, such as photovoltaic (PV) energy, has been decisive in curbing the increase in conventional and thus reduce the production of greenhouse gases. Optimum matching of loads to PV generator is most desirable for more accurate sizing. Because of the high PV generator's cost, the system designer is mainly interested in its full utilization by optimum matching of the system components during all operating period. Application of PV power to electromechanical loads requires an understanding of the dynamics of such systems. Our system has a hybrid and complex character and requires a good modeling of the energetic point of view before passing the phase of design of control laws. So, I use the graphical approach of modeling called dedicated bond graph for this type of system, and this tool showed very interesting results in the level of the modeling, dimensioning, monitoring, and diagnostics. The application of bond graph technique for the modeling of PV systems is not yet widespread. On the other hand, in order to ensure optimal operation of the system, to guarantee maximum output energy, and to reduce the adverse effects due to load disturbances, it is necessary to have a robust control of the induction machine against its composition and the existence of the coupling between the magnetic flux and the driving torque on the one hand and on the other hand the use of an estimator for the reconstruction of the flux, which is an almost unmeasurable quantity (requires an expensive and fragile). The purpose of this work is to study the pumping station coupled to a PV generator by a graphical modeling called bond graph, after which I design the laws of robust commutations by fuzzy logic. The design of robust control laws using fuzzy logic in the vector control aims to determine the maximum power point by the optimized P&O algorithm, to control of the mechanical speed of the pump, and to determinate of the reference speed that I get a maximum efficiency of the structure. The results of simulations show the robustness and performance of these fuzzy controllers.

Intelligent Control of the Microclimate of an Agricultural Greenhouse Powered by a Supporting PV System

“…The inverter is controlled by a pulse width modulation strategy. Figure 22 shows a schematic diagram of the inverter feeding a three-phase motor, while the technical specifications are reported in Reference [31]. The three arms of the inverter are controlled by the vector ( ) , with In the proposed test lab greenhouse, the converter model DV51-322-2K2 is used, with the following values of the components:…”

“…When this on-off sequence is iterated several times to regulate the temperature, the energy consumption is high. The main advantage of this technique is its easy control algorithm, because only the stator current and voltage are measured in estimating the torque and flux [31]. This control strategy allows for a reduction in energy consumption.…”

Bond graph modelling and control enhancement of an off‐grid hybrid pumping system by frequency optimization

“…In particular, the possibility of including renewable energy sources is increasingly appreciated . Moreover, the complexity of the description of dynamic operation and the classifications of pumping stations and the multiple parameters involved in these systems have forced researchers to develop simplified models based on different approaches …”

Development of grid‐connected solar water pumping system utilizing diode bridge

“…6,7 SWPS is popular because it is fuel free, maintenance free, and eco-friendly compared with traditional diesel engine-based pumping technology. In recent scenario, SWPS can be divided in three categories, viz, stand-alone SWPS, 8,9 battery-supported SWPS, 10 and grid-supported SWPS. 11,12 Stand-alone SWPS are available in two configuration, ie, single-stage and two-stage.…”