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Viz analyze the effects of the faults that are most likely to affect the control circuitry of photovoltaic (PV) arrays, that is their Maximum Power Point Tracker (MPPT) and DC-AC converter. Particularly, we study their possible impact on the efficiency of the whole PV system and we prove that they may produce catastrophic effects on the PV array power efficiency. Based on these achieved results, we then propose two novel low-cost approaches for the concurrent detection of the faults most likely to affect the MPPT and the DC-AC converter. These approaches could allow the activation of proper reconfiguration schemes upon fault detection, thus avoiding the detrimental effects on the PV system efficiency due to such faults occurrence. [ABSTRACT FROM PUBLISHER]

In this paper we proposed a novel inverter to convert a DC voltage to a desired AC voltage. This inverter is designed for variable inductive loads and low output power applications. We proposed a novel simple PWM method which enables the inverter to keep the output current at six times more than the rated output current, without reducing output voltage value. In addition, based on a simple use of resonance in the circuit, the new inverter can raise the output voltage to extremely high amplitude for a relatively short time. These characteristics make the proposed inverter is useful for some industrial applications such as electrical vehicle. The new configuration of the circuit consists of a unidirectional switch, two inductors (to transfer energy), a fast diode and a capacitor. With very few elements, this system changes the input DC voltage to a desired sinusoidal AC voltage. Some advantages of this system are: number of power electronics devices is low - it only uses a simple switch; it does not need dead time, in spite of conventional inverters which need a dead time between switches to prevent from short-circuiting; volume of the circuit is very small; the total harmonic distortion (THD) is greatly reduced; and it works with high efficiency. Another advantage of this inverter is capability of the circuit in boosting or bucking the input voltage to a desirable output voltage without using any DC-DC converters. It is flexible in keeping output voltage constant when the output current is increased, and it can produce the extremely higher output voltage than input voltage. The main drawback of the method, compared with conventional voltage source inverters, is that it uses more energy storage elements in spite of its low volume of power. We used simulations to prove all these statements. [ABSTRACT FROM PUBLISHER]

This article focuses on AC-AC power converter that can be used for uninterruptible power supply (UPS). The converter is built on two stages: a AC-DC input stage and a DC-AC output stage. The two blocks are connected by an intermediate DC bus. The aim of control is threefold: i) power factor correction ii) regulation of DC bus iii) generating a sinusoidal voltage at the output. The synthesis of controllers has been achieved through the technique of nonlinear backstepping control. A detailed analysis of the stability control system is presented. The performances of controllers have been validated by numerical simulation in MATLAB / SEVIULINK. [ABSTRACT FROM PUBLISHER]

A photovoltaic system connected to the grid is constituted by two main parts: a solar cell and a power converter DC-AC. The impedance adaptation between the two parties is a technological problem that essentially means the transfer of maximum power of PV generator to the grid. In this paper, a new technique for nonlinear control of power converter DC-AC is presented. This converter is built on two stages: a DC-DC stage and a DC-AC stage. The two blocks are bound by a DC voltage intermediate bus. The control objective is threefold: i) control the input voltage of the converter to find the MPP (maximum power point), ii) regulating the DC bus voltage, iii) generate a sinusoidal current at industrial frequency that will be injected into the network with a power factor near unity. The synthesis of controllers was performed using the technique of backstepping nonlinear control. A detailed analysis of the stability control system is presented. The performance of controllers has been validated by numerical simulation in MATLAB / SIMULINK. [ABSTRACT FROM PUBLISHER]

This paper proposes a new current source inverter using a coupled inductor, which is derived from the circuit of the matrix converter using an additional inductor. The proposed circuit has the bidirectional power conversion ability, providing step-up and step-down operation in each direction, and can switch the direction of the power flow instantaneously. This paper describes the principle of operation, the simulation results and the experimental results of the proposed circuit. [ABSTRACT FROM PUBLISHER]

A novel concept of low harmonic three-phase inverter is presented. The solution is using novel magnetic component CSM (current splitter/merger) and twelve active switches (e.g. IGBTs). Switches together with CSM convert DC current of the power source into low harmonics three-phase AC current, which is injected to the power line. The most important features of the solution are: low harmonics, high efficiency, very simple and robust control of the switches, very low EMI distortions and excellent reliability. All above features are achieved using low cost components like low speed power switches and novel magnetic component CSM. Proposed solution can be seen as a low cost, low loss, high reliability alternative to the widely used switch-mode PWM inverters [ABSTRACT FROM PUBLISHER]

This paper proposes a bidirectional grid interface converter to be applied in Energy-Control-Center (ECC) in order to interface dc variables, such as battery energy storage system and ac conventional utility grid. Such power electronics solution guarantees: (i) bidirectional power flow between dc and ac converter sides, (ii) independent control in both sides, (iii) high level of integration, and (iv) implementation of two functions using a unique power conversion stage. Despite proposing a new solution, this paper presents an analysis of the converter in terms of: PWM strategy, dc-link capacitor variables, switches variables, low-pass-filter specification employed at the output converter sides and a comparison with a conventional solution. Simulation and experimental results are presented as well. [ABSTRACT FROM PUBLISHER]

Multi level inverter technology has overcome the common three level inverters, as for the better output and performance, one of the most common use of the inverter is to produce pure sine wave from dc supply however this paper present Multi level inverter to be used as harmonic source, this paper will discuss the Inverter configuration to produce 9 levels output (typical) or can be boosted to produce 11 or 13 with using 2 extra switches. This paper discusses the switching strategy to control the inverter, and calculate the switching angles for the required output signal. [ABSTRACT FROM PUBLISHER]

In this paper a novel dual functional converter has been proposed. The new configuration of the circuit works based on bifilar method. By a simple technique, using pulse width modulation method, this double functional converter can produce both ac or dc voltage as user defines regardless of variation of the input voltage amplitude. This new structure has a significant advantageous in the photovoltaic applications. In This converter, the output voltage is easily switched between two different modes. In addition, Power electronics devices have been reduced and it only uses a simple switch. The volume of circuit is relatively small. The total harmonic distortion (THD) for ac outputs has been greatly reduced. Besides, the new inverter works with high efficiency. All these statements have been greatly proved in the simulation results. [ABSTRACT FROM PUBLISHER]