Less-conventional low-consumption galvanic separated MOSFET-IGBT gate drive supply

A simple half-bridge, galvanic separated power supply which can be short circuit proof is proposed for gate driver local supplies. The supply is made while hacking a common mode type filter as a transformer, as the transformer shows a good insulation, it has a very low parasitic capacitance between primary and secondary coils, and it is cost-effective. Very low standby losses were observed during lab experiments. This makes it compatible with energy efficient drives and solar inverters

Using numerical inverse laplace for optimizing the current control in grid coupled inverters

Abstract— A number of control circuits can be well analyzed in a Fourier transfer function, but they have problems in being analyzed in an analytical inverse Laplace response as they contain distributed poles and zeroes, coming from a time delay or other effects. An example is the control of converters with filter circuits. In this paper, a control is shown in a PV converter with a very small DC link capacitor which is normally difficult to stabilize due to the presence of resonance effects of filters. It is observed that a second order high pass filter feedback stabilizes well parasitic resonances, even if their frequency is not very low compared to the switching frequency. A numeric inverse Laplace can be implemented in almost any mathematical program. This paper shows how parameters can be obtained from a step response using the numerical inverse Laplace and be used in Matlab simulation. It shows the complementarity between two methods

Euro-African business partnership on the forefront: opportunities and challenges with case study of Photovoltaic converter business

Europe, a pioneer trader with Africa, has had a lot of opportunities to make a business partnership with Africa not only in natural goods but also in technology. Africa middle class has recently been growing and many people have been moving from rural areas to big cities. This makes Africa need more energy. Having the solar energy potentiality, Africa opts to use solar as source of energy which can intervene in different sectors such agri-business. This could be an opportunity for Europe to trade efficiently its PV and converter technology with Africa. The paper briefly shows that China has been dominating not only the industrial Africa market but also the labor jobs since 1990s. Furthermore, it presents the potentialities of Europe which can be exploited for PV converter business partnership with Africa. It presents that Europe can design some industrial products that meet the African climate condition and life style. In this document, development of a specific long life PV converter is considered and its financing and the total cost ownership are discussed

Reduced losses in PV converters by modulation of the DC link voltage

The efficiency of a PV system has improved by the fact that the researchers have used different techniques to enhance their efficiency. This paper aims to present how the PV converter losses can be reduced by employing a polypropylene capacitor in the DC link and to modulate that DC voltage. A problem of controllability and stability arises. Two current control methods, constant off time and a PWM type with second order high pass filter DC-link feedback are presented. Polypropylene capacitors in the PV converters do have lower losses and a lower cost. The PV converter simulation and lab experiment is based on a three-phase bridge APTGF50X60T3G, used to combine a step-up/step down and H-bridge in one package

Frequency synchronization of a single-phase grid-connected DC/AC inverter using a double integration method

Many traditional grids have started to integrate the DC/AC inverters in their networks. This requires a good control to enhance the power quality. The grid frequency behaviour is one of the principal indicators that reveal the power quality. Therefore, it must be strongly controlled. Up to now, the most popular frequency synchronization method is based on phase-locked loop (PLL) control. It is known that setting a current proportional to voltage does not work well and it creates a negative resistor in a wide frequency range because the circuit is not passive. This paper presents an alternative idea of synchronization of a single-phase grid-connected DC/AC inverter by using a double integration method. It is simpler than PLL since it needs neither a phase comparator, nor a local oscillator. It provides a signal in phase with the current. The art of the method is how to remove the integrating constants without degrading the signal

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Many scholars have been focusing on the energy management by Integrating a smart grid into a conventional electrical grid. They have showed that to meet a certain power demand of the consumers, using energy management, the electric utility can turn on some generators, which may have the least operation cost, while the generators with high operation cost are left to supply extra load demand in specific peak periods. Henceforth, the operation cost of its generation units is minimized. The issue remains at a level of relating the energy management to CO2 emission. The present paper briefly discusses the Rwandan electrical network that still integrates the use of diesel generators. It estimates the amount of CO2 emission that can be avoided once a PV system is integrated into the electrical network. The paper as well proposes an algorithm for energy management with consideration of CO2 emission

Direct DC use of PV for cooking and sanitary

The energy from solar can easily harnessed to be used for various applications and grid injection. For cooking, different techniques can be utilized. Some people use the sun to cook. Other people use batteries and inverters even at noon. Hence, the cooking system becomes expensive. In fact, Photovoltaic panels did not decrease considerably in price. This paper proposes a simple electronic circuit that a Photovoltaic system can directly be used for cooking. The circuit aims at facilitating a cooking plate user to set a duty ratio. The duty ratio is limited to maintain the array voltage above a minimal level to avoid that it operates too far away from the maximal power point when less power is available. Moreover, it shows to be cost-effective compared to Photovoltaic grid connected and to charcoal. REFERENCE