Vector control of an induction motor fed by a photovoltaic generator

With the continuous decrease of the cost of solar cells, there is an increasing interest in photovoltaic (PV) system applications. Electric motors powered by solar-cell generators are one of the most important applications, such as in water pumping systems. This paper investigates a photovoltaic-electro mechanic chain, composed of a PV generator, an impedance adapter DC-DC converter, a storage battery and a vector controlled induction machine. The PV generator is forced to operate at its maximum power point by using an appropriate search algorithm, and a balance between battery charge and motor supply is also ensured in all insolation conditions. Simulation results show the effectiveness and feasibility of such an approach.PV generator Impedance adapter Storage battery Vector control and induction machine

Thermal modelling of cooling tool cutting when milling by electrical analogy

Measurement temperatures by (some devises) are applied immediately after shut-down and may be corrected for the temperature drop that occurs in the interval between shut-down and measurement. This paper presents a new procedure for thermal modelling of the tool cutting used just after machining; when the tool is out off the chip in order to extrapolate the cutting temperature from the temperature measured when the tool is at stand still. A fin approximation is made in enhancing heat loss (by conduction and convection) to air stream is used. In the modelling we introduce an equivalent thermal network to estimate the cutting temperature as a function of specific energy. In another hand, a local modified element lumped conduction equation is used to predict the temperature gradient with time when the tool is being cooled, with initial and boundary conditions. These predictions provide a detailed view of the global heat transfer coefficient as a function of cutting speed because the heat loss for the tool in air stream is an order of magnitude larger than in normal environment. Finally we deduct the cutting temperature by inverse method

Thermal modelling of cooling tool cutting when milling by electrical analogy

Measurement temperatures by (some devises) are applied immediately after shut-down and may be corrected for the temperature drop that occurs in the interval between shut-down and measurement. This paper presents a new procedure for thermal modelling of the tool cutting used just after machining; when the tool is out off the chip in order to extrapolate the cutting temperature from the temperature measured when the tool is at stand still. A fin approximation is made in enhancing heat loss (by conduction and convection) to air stream is used. In the modelling we introduce an equivalent thermal network to estimate the cutting temperature as a function of specific energy. In another hand, a local modified element lumped conduction equation is used to predict the temperature gradient with time when the tool is being cooled, with initial and boundary conditions. These predictions provide a detailed view of the global heat transfer coefficient as a function of cutting speed because the heat loss for the tool in air stream is an order of magnitude larger than in normal environment. Finally we deduct the cutting temperature by inverse method

Contribution to the Protection of PVG Connected to Three Phase Electrical Network Supply

AbstractIn this paper we propose to investigate, model, optimize and simulate the connection of a 3Kwc domestic photovoltaic generator to the three-phase power network throughout a current-controlled voltage source inverter. The current-controlled voltage source inverter tasks are:•Tracking the PVG maximum power point.•Injecting the maximum power into a three phase electrical network with unit power factor.The totality of the produced energy by the PVG has to be injected in the network, whereas the electricity requirement for domestic use has to be withdrawn from the network supply .This is in order to avoid batteries storage problems .As well as the realization of a decoupling system which can protect the generator from perturbations that can reach the electrical network supply