Rahmi Ilker Kayaalp

Simulation modelling and analysis of modular cascaded multilevel converter based shunt hybrid active power filter for large scale photovoltaic system interconnection

Abstract Modular multilevel inverters are promising candidates for next generation of efficient, robust and reliable inverters in large scale photovoltaic system. A modular cascaded multilevel inverter based shunt hybrid active power filter (SHAPF) for three phase grid-connected large scale PV systems is represented in this paper. The main contribution of this paper is to model and control of grid interfaced large scale photovoltaic system with embedded hybrid active power filter functions. In proposed system, the features of hybrid active power filter have been amalgamated in the control circuit of the voltage controlled voltage source inverter interfacing the photovoltaic system to the grid. As a result, the same inverter part of SHAPF is utilized to inject power generated from photovoltaic source to the grid and also to act as hybrid active power filter to compensate harmonics and reactive power demand. With using compensation ability, the grid currents are sinusoidal and in phase with grid voltages. The whole system is modeled in PSCAD/EMTDC. The simulation results are demonstrated to verify the operation and the control system of the proposed system.

A novel fuzzy logic control for bidirectional DC-DC converter and comparison with dual phase-shift control method in medium voltage applications

In this study, operation, design and comparison of Dual Phase-Shift and Novel Fuzzy Logic control methods on isolated bidirectional DC-DC converter are discussed. The major components (DC link capacitors and inductors) are created for dual phase shifting method in order to obtain maximum efficiency. Triggering signals, voltage-current waveforms are compared and efficiencies are listed for all of these control methods at buck and boost modes of the full-bridge converter topology without using snubber capacitors to reduce cost feasibility. The main contribution of this paper, applying one of the most common used phase-shift control method, dual phase-shift and comparing with proposed novel Fuzzy Logic control method (Fuzzy-PSO-PI) on efficiency way for medium voltage applications. In this paper, isolated bidirectional DC-DC converter topology is modelled and control algorithms are written by FORTRAN programming language.

Performance investigation of high level modular multilevel inverter based shunt hybrid active power filter

The multilevel inverters have become popular equipment for medium and high power applications in recent years. These inverters can constitute high voltage and decrease harmonics by their own circuit topologies. This paper presents a modular multilevel inverters based SHAPF for medium voltage applications, focusing on its control method and operating performance. The compensation process is based on synchronous reference frame method. Theoretical analyses and simulation results are obtained from an actual industrial network model in PSCAD. The simulation results are presented for a proposed system in order to demonstrate that the harmonic compensation performance meets the IEEE-519 standard.

PSO-PI Based DC Link Voltage Control Technique for Shunt Hybrid Active Power Filter

In power systems, the intensive use of nonlinear loads causes several power quality problems such as current harmonic pollution. In order to reduce the current harmonic pollution, the shunt hybrid active filter (SHAPF) is the best solutions effectively. In shunt hybrid active filter systems SHAPFs, the design of dc link controller is a significant and challenging task due to its impact on the performance and stability of the overall system. The main contribution of this paper is that the particle swarm optimization (PSO) algorithm is applied gains for PI controller which can result in the improved response in terms of response time and overshoot. In proposed control method, the performance results of harmonic compensation are satisfactory. Theoretical analyses and simulation results are obtained from an actual industrial network model in PSCAD. The simulation results are presented for proposed system in order to demonstrate that the harmonic compensation performance meets the IEEE-519 standard.

Adaptive Input Voltage Prediction Method Based on ANN for Bidirectional DC-DC Converter

For industrial applications, Bidirectional DC-DC converters (BDCs) are used in recent years. And also their efficiency results are improved to apply different control methods. ANN algorithms is one of the new control topic in literature. This paper attempts to improve the dynamic performance of bidirectional dc-dc converter. And it deals with a novel control scheme related with an adaptive input voltage control by using ANN algorithms based on SOM. Firstly, adaptive input voltages are classified by ANN algorithms (SOM, SVM, FF) and the best suitable and proposed ANN algorithm is SOM which is selected for this controller. The best efficiency case is selected in this algorithm. Then, the voltage values are predicted. This voltage values are used in simulation models. Thus, the proposed system works both effective and high efficiency. Theoretical analysis and simulation results obtained from an actual industrial network model in PSCAD verify the viability and effectiveness of the proposed Bidirectional DC-DC Converter (BDC).

A Power Rating and Application Survey of Magnetically Controlled Shunt Reactor

MCSR can simplify the system reactive power and voltage control in the super / special high-voltage power grid, suppress power frequency and operation over voltage, eliminating generator self excitation, dynamically compensate charging the power in a transmission line, suppress the secondary arc current, damping system resonance and so on, which can meet the various needs of the system, it has a very broad application prospects. This paper presents a power rating and application survey of MCSR. It is aimed at providing a broad perspective on the status of MCSR technology to the researchers and the application engineers dealing with power quality issues. A list of more than 45 research publications on the subject is also appended for a quick reference.