Application of a CC-VSI for Active Filtering and Photovoltaic Energy Conversion with a 1-to-1 MPPT Controller

This paper focuses on the implementation of a three-phase four wire current-controlled Voltage Source Inverter (CC-VSI) as both PV energy extraction and power quality improvement. For power quality improvement, the CC-VSI works as a grid current-controller shunt active power filter. Then, the PV array supported by a Look-up Table type of a MPPT controller is coupled to the DC bus of the CC-VSI. The output of MPPT controller is a DC voltage that determines the DC-bus voltage according to the PV maximum power. The computer simulation results show that the system works properly in steady state and dynamic condition

Simple Integration of Three-phase Shunt Active Power Filter and Photovoltaic Generation System with Fibonacci-Search-Based MPPT

This paper proposes a three-phase four wire current-controlled Voltage Source Inverter (CC-VSI) for both harmonic mitigation and PV energy extraction. For harmonic mitigation, the CC-VSI works as a grid current controlling shunt active power filter. Then, the PV array is coupled to the DC bus of the CC-VSI. The MPPT controller employs the Fibonacci search method. The output of MPPT controller is a DC voltage that determines the DC-bus voltage according to the PV maximum power. From computer simulation, the CC-VSI can effectively compensate for harmonics as well as deliver PV power to the grid

Simulation-based coyote optimization algorithm to determine gains of PI controller for enhancing the performance of solar PV water-pumping system

In this study, a simulation-based coyote optimization algorithm (COA) to identify the gains of PI to ameliorate the water-pumping system performance fed from the photovoltaic system is presented. The aim is to develop a stand-alone water-pumping system powered by solar energy, i.e., without the need of electric power from the utility grid. The voltage of the DC bus was adopted as a good candidate to guarantee the extraction of the maximum power under partial shading conditions. In such a system, two proportional-integral (PI) controllers, at least, are necessary. The adjustment of (Proportional-Integral) controllers are always carried out by classical and tiresome trials and errors techniques which becomes a hard task and time-consuming. In order to overcome this problem, an optimization problem was reformulated and modeled under functional time-domain constraints, aiming at tuning these decision variables. For achieving the desired operational characteristics of the PV water-pumping system for both rotor speed and DC-link voltage, simultaneously, the proposed COA algorithm is adopted. It is carried out through resolving a multiobjective optimization problem employing the weighted-sum technique. Inspired on theCanis latransspecies, the COA algorithm is successfully investigated to resolve such a problem by taking into account some constraints in terms of time-domain performance as well as producing the maximum power from the photovoltaic generation system. To assess the efficiency of the suggested COA method, the classical Ziegler-Nichols and trial-error tuning methods for the DC-link voltage and rotor speed dynamics, were compared. The main outcomes ensured the effectiveness and superiority of the COA algorithm. Compared to the other reported techniques, it is superior in terms of convergence rapidity and solution qualities

Integrasi Filter Daya Aktif dan Transfer Energi Surya dengan Menggunakan Inverter

CC-VSI berfungsi sebagai filter daya aktif tipe paralel dan sekaligus pengatur aliran daya aktif dari penel surya ke gri

Microsource interface for a microgrid

A MicroGrid is typically a small power system, which consists of several microsources and energy storage units, providing heat and electricity to local loads. The MicroGrid has the capability to island and operate autonomously from the main utility network. MicroGrids potentially enable a greater integration of small-scale renewable energy sources. The objective of this thesis is to develop a single-phase microsource interface with energy storage unit embedded into the interface. An integrated energy storage unit avoids the necessity of a separate stand-alone energy storage unit in the MicroGrid. Thus the 'plug-and-play' functionality of the MicroGrid can be improved. A collection of power electronic converter based microsources with storage units connected to form a MicroGrid is a complex system. Development of such simple controllers, which decouple the effect of sub-unit while achieving the desired 'plug-and-play' capabilities, is a complex but important challenge. A photovoltaic panel was considered as the microsource and a battery bank was used as the energy storage unit. The proposed microsource interface consists of three power electronic converters. A photovoltaic panel is connected to a unidirectional dc-dc converter and its output is connected to the input of the single-phase inverter which can be connected to the MicroGrid. Energy storage is connected to the dc-link,which is the input of the single-phase inverter, through a bi-directional dc-dc converter. A simulation model of a photovoltaic panel was developed in the EMTDC/PSCAD software. The limitations of the model and a method to reduce these limitations are discussed. For the experimental validation of the proposed system, an adjustable-voltage-regulator hardware photovoltaic emulator was designed. The characteristic curves of the hardware emulator are compared with those obtained from the simulation model. A controller was designed for the unidirectional dc-dc converter to keep the output voltage of the photovoltaic panel at a given reference. Similarly the controller of the bi-directional dc-dc converter was designed to keep the dc-link voltage approximately constant. The behaviour of the dc-dc converters, which are connected to microsource and energy storage unit, around the steady state and worst-case scenarios was analysed, simulated and experimentally validated. Simulation and experimental results are compared. A current controller, based on instantaneous measured current, was implemented. This was designed to achieve good dynamic stiffness and command tracking properties. Furthermore a smooth grid connection method with the aid of the current controller is presented. The ability of the inverter to control the active and reactive power output was also analysed and verified with the aid of the simulation model and experimental set-up. Results corresponding to current controller, grid connection and power control are presented. The integrated system was simulated in EMTDC/PSCAD. The system response to the variations in the microsource and inverter output power variations was analysed. A smooth start-up method is shown which reduces the inrush current. Simulation results corresponding to different case studies and start-up transient are also included.EThOS - Electronic Theses Online ServiceGBUnited Kingdo