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This article presents a grid-connected photovoltaic (PV) system using the classical DC-DC buck converter, which is responsible for stepping down the resulting voltage from several series-connected panels. Besides, the structure provides high power factor operation by injecting a quasi-sinusoidal current into the grid, with near no displacement in relation to the line voltage at the point of common coupling among the PV system and the loads. A CSI employing thyristors is cascaded with the DC-DC stage so that AC voltage results. The inverter output voltage level is adjusted by using a low-frequency transformer, which also provides galvanic isolation. The proposed system is described as mathematical approach and design guidelines are presented, providing an overview of the topology. An experimental prototype is also implemented, and relevant results to validate the proposal are discussed. [ABSTRACT FROM AUTHOR]

This paper describes the construction of new circuit configurations for some sequential circuits. These circuits are based on the microthyristor as a microelectronic bistable device that can store logic one and logic zero and on NMOS transistors that act either as pass transistors or drivers. The shift register, considered as a main type of sequential circuit, is developed from a D flip-flop that is designed basically from the microthyristor as a bistable device. Moreover, different types of counters based on the microthyristor as a storing element are developed. Microthyristor sequential circuits were found to perform well. [ABSTRACT FROM AUTHOR]

This paper describes the development of new configurations for flip-flops which are based on a microthyristor as a storage element, the NMOS transistor as a series switch or a driver and a high pull-up resistor. The performance of these flip-flops is analysed, using a PSPICE simulator. These devices perform well with regard to speed and power consumption and are more compact because of the use of the microthyrister. [ABSTRACT FROM AUTHOR]

Development of a sequential machine model of a thyristor considering ‘turn-on’ and ‘turn-off’ time of the device is presented. A model of a thyristor along with the snubber circuit is also developed. The models are used to illustrate the operation of a thyristor chopper where the thyristors are protected by snubbers. The model is useful in analysis and design of circuits employing a number of thyristors. [ABSTRACT FROM AUTHOR]

Describes a two-level circuit model for a gate turn-off thyristor in power electronic simulations. Basis of the semiconducting phenomena; Incorporation of additional charge control, anode-cathode and gate-cathode resistance modulation networks to simulate turn-off phenomena; Methods for determining the model parameters.