Low Power Photovoltaic Converter Control and Development

The paper focuses on design and simulation ofthe low power inverter for photovoltaic application. In thepaper it is briefly discussed the DC/DC converter design forthe tracking MPP of the solar array and then the design ofthe control algorithm for the output inverter is discussed.Both possible operation modes - work in “island mode” andoperation in the supply grid are considered and a controlalgorithms for them were developed and simulated.Attention is also paid to the design of the output filter forthe converter

Single Phase Voltage Source Inverter Photovoltaic Application

Photovoltaic applications have been developing and spreading rapidly in recent times. This paper describes the control strategy of the Voltage Source Inverter that is the important tail end of many photovoltaic applications.In order to supply the grid with a sinusoidal line current without harmonic distortion, the inverter is connected to the supply network via a L-C-L filter. The output current is controlled by the hysteresis controller. To improve the behaviors of the L-C-L filter, active damping of the filter is being used. This paper discusses controller design and simulation results

Novel Topology for Four-Quadrant Converter

Particle accelerators, like the LHC (Large Hadron Collider), make use of true bipolar power converters to feed superconducting magnets. Moreover, the LHC imposes that most converters must be installed underground. This constraint leads to the necessity of a high efficiency and a reduced volume for all the power converters. In this paper, the authors present a novel four-quadrant topology composed by an association of a ZVS-inverter and a ZCS-rectifier. This DC-AC-DC converter is fully reversible and a soft-switching operation mode is achieved for all switches over the full operating range. After a thorough analysis of the prototype design [±600A, ±10V], simulation and experimental results confirm the general performance of this power structure

High frequency inverter-transformer-cycloconverter system for DC to AC (3-phase) power conversion

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.This thesis is concerned with a 3-phase multistage high frequency link DC to AC power conversion with a novel inverter-cycloconverter circuitry. The conversion system is composed of a high frequency PWM inverter, step-up high frequency transformer and cycloconverter with bidirectional switching devices. In first stage the DC voltage of the power source , say a submarine battery, is inverted to a system of 3-phase sinusoidally modulated I kHz alternative wave forms. For this purpose a suggested optimized PWM technique for 3-phase inverter operation is adopted, in which harmonic components up to 17 th ( 17 kHz) are eliminated from the inverter output voltages. In the second stage, for DC input isolation from AC output and also for a voltage transformation ( here stepping-up )a high frequency ( size reduced ) transformer is employed. Generalized high frequency operation, influence and side effects of the transformer on overall system design & performance is investigated. In the final stage the 1 kHz -to- 50 Hz conversion process is accomplished by a 3-phase cycloconverter. The proposed "nonlinear modulation strategy" for cycloconverter output voltage and associated harmonic analysis is demonstrated, in which the harmonic components up to 38th (1.9 kHz ) are eliminated from the conversion system output voltage. To assess the suggested functioning principles for the inverter & cycloconverter , the prototype conversion system was developed. Some design criteria and switching device selection are presented, together with different voltage & current wave forms of the prototype system under resistive & inductive load (induction motor) and their respective spectra

RF CMOS Transmitter Front-end with Output Power Combiner

In this thesis strategies to achieve a high efficiency RF front-end are studied and presented. A high efficiency Power Amplifier is also proposed and simulated. The applications for this type of designs are vast, but the main ones are in mobile transmission devices where the only power supply source available is a battery. In order to perform this thesis several topologies of power amplifiers were studied, and the decision fell to those based on a switching behavior. The reason for this decision was the need for high efficiency (it’s one of the main objectives). The Class-D power amplifier with its ideal potential efficiency of 100% has proven the most promising for implementation. The objectives for this thesis in terms of implementation were an efficiency of 20% and an output power of 0dBm. Finally, a power-combining technique was used to explore the potential of achieving high output power without affecting the efficiency