Impact Of Photovoltaic Systems Integration On Electricity Distribution Networks

Traditionally, power systems are designed to operate in a unidirectional power flow. In the past few years, integration of solar photovoltaic (PV) systems on distribution network has grown rapidly given its potential technical and economic benefits, which include higher network utilization, enhanced reliability and loss reduction. However, the high PV generation during low demand periods may cause potential network problems. In addition, PV generation depends directly to the sun irradiance which could potentially cause problems in the cases of high PV penetration level. The intermittency of the power generated from the PV plants may introduce voltage fluctuation and power quality issues. These issues may limit the PV penetration level and hence necessary measures are needed to alleviate the potential problems. This dissertation investigates the steady state impact of the PV plant penetration on the operation of power distribution networks. This includes the impact of PV generation of the network losses. In addition, the light and heavy load cases have been considered in this work to analyze their respective impact on the network voltage. The maximum PV penetration level that can be injected into the grid is identified. Mitigation strategy has also been proposed to control the voltage fluctuation that caused by PV plants. Standard IEEE distribution test cases have been modeled by utilizing OpenDss simulator. These test cases were used to perform the case studies of distribution systems in order to evaluate the impact of grid connected PV systems. The results indicate that the integration can have a positive impact and negative impact on the connected grids. The interest lies in the voltage improvement at load buses and the reduction in the system losses. The maximum capacity and the impact of the PV on the grid connected system depend on the PV size, installation location and system topology. The results also show that the STATCOM technique can effectively reduce the voltage fluctuation in the network

Impact of hybrid renewable energy systems on short circuit levels in distribution networks

The effects of the distributed generation can be classified as environmental, technical and economical effects. It is playing a very vital role for improving the voltage profiles in electrical power systems. However, it could have some negative impacts such as operating conflicts for fault clearing and interference with relaying. Distribution system is the link between the utility system and the consumer. It is divided into three categories radial, Loop, and network. Distribution networks are the most commonly used to cover huge number of loads. The power system reliability mainly depends on the smooth operation and continuity of supply of the distribution network. However, this may not always be guaranteed especially with the introduction of distributed generation to the distribution network. This paper will examine the impact of hybrid renewable energy systems (using photovoltaic and doubly fed induction generators) on short circuit level of IEEE 13-bus distribution test system using ETAP software

Connection of renewable energy sources to the power grid

Diplomová práce se zabývá obnovitelnými zdroji energie a druhy, které se nejvíce využívají. Teoretická část je věnována obecným informacím o obnovitelných zdrojích energie, typech elektráren a v další části se zaměřuje na fotovoltaické elektrárny. Praktická část ilustruje připojení fotovoltaické elektrárny do sítě vysokého napětí (22kV) ve Středočeském kraji. Dále jsou v práci uvedena pravidla pro připojení rozptýlených výroben elektřiny z obnovitelných zdrojů energie do distribuční sítě, napěťový profil podél vedení před a po připojení FVE do distribuční sítě.This thesis deals with the renewable energy and its main types. The theoretical part is about the general information on renewable energy sources, types of power plants, focusing on photovoltaic power plants. The practical part illustrates the connection of photovoltaic power plant to a medium voltage network (22kV) in Central Bohemia region. The following part is devoted to the rules for connecting dispersed energy sources to the distribution network, voltage profile along the lines before and after connecting the PVPP's into the distribution network

Ancillary Services in Hybrid AC/DC Low Voltage Distribution Networks

In the last decade, distribution systems are experiencing a drastic transformation with the advent of new technologies. In fact, distribution networks are no longer passive systems, considering the current integration rates of new agents such as distributed generation, electrical vehicles and energy storage, which are greatly influencing the way these systems are operated. In addition, the intrinsic DC nature of these components, interfaced to the AC system through power electronics converters, is unlocking the possibility for new distribution topologies based on AC/DC networks. This paper analyzes the evolution of AC distribution systems, the advantages of AC/DC hybrid arrangements and the active role that the new distributed agents may play in the upcoming decarbonized paradigm by providing different ancillary services.Ministerio de Economía y Competitividad ENE2017-84813-RUnión Europea (Programa Horizonte 2020) 76409

Decoupling and Control of Real and Reactive Power in Grid-Connected Photovoltaic Power System

The paper presents a detailed modeling and simulation of different control schemes of the real and reactive power flows in a three-phase voltage source inverter (VSI) interfacing a photovoltaic (PV) generation system to the power grid. Synchronisation of the inverter and grid AC waveforms is achieved using a phase-locked-loop (PLL) circuit. An effective decoupling strategy based on proportional-integral (PI) controllers is designed to eliminate the interaction between the two current components. Finally, the influence of the grid disturbances on the PV system and the influence of the solar energy intermittency on the power grid have been tested. The overall model is implemented in Matlab and Simulink/SimPowerSystems toolboxes. Simulations results with the PV system operating with real irradiance data will be presented to demonstrate the performance of the proposed decoupling and control strategies under different conditions of the power gridNon peer reviewe

Power Quality Improvement and Low Voltage Ride through Capability in Hybrid Wind-PV Farms Grid-Connected Using Dynamic Voltage Restorer

© 2018 IEEE. Translations and content mining are permitted for academic research only. Personal use is also permitted, but republication/redistribution requires IEEE permission.This paper proposes the application of a dynamic voltage restorer (DVR) to enhance the power quality and improve the low voltage ride through (LVRT) capability of a three-phase medium-voltage network connected to a hybrid distribution generation system. In this system, the photovoltaic (PV) plant and the wind turbine generator (WTG) are connected to the same point of common coupling (PCC) with a sensitive load. The WTG consists of a DFIG generator connected to the network via a step-up transformer. The PV system is connected to the PCC via a two-stage energy conversion (dc-dc converter and dc-ac inverter). This topology allows, first, the extraction of maximum power based on the incremental inductance technique. Second, it allows the connection of the PV system to the public grid through a step-up transformer. In addition, the DVR based on fuzzy logic controller is connected to the same PCC. Different fault condition scenarios are tested for improving the efficiency and the quality of the power supply and compliance with the requirements of the LVRT grid code. The results of the LVRT capability, voltage stability, active power, reactive power, injected current, and dc link voltage, speed of turbine, and power factor at the PCC are presented with and without the contribution of the DVR system.Peer reviewe

Power quality and electromagnetic compatibility: special report, session 2

The scope of Session 2 (S2) has been defined as follows by the Session Advisory Group and the Technical Committee: Power Quality (PQ), with the more general concept of electromagnetic compatibility (EMC) and with some related safety problems in electricity distribution systems. Special focus is put on voltage continuity (supply reliability, problem of outages) and voltage quality (voltage level, flicker, unbalance, harmonics). This session will also look at electromagnetic compatibility (mains frequency to 150 kHz), electromagnetic interferences and electric and magnetic fields issues. Also addressed in this session are electrical safety and immunity concerns (lightning issues, step, touch and transferred voltages). The aim of this special report is to present a synthesis of the present concerns in PQ&EMC, based on all selected papers of session 2 and related papers from other sessions, (152 papers in total). The report is divided in the following 4 blocks: Block 1: Electric and Magnetic Fields, EMC, Earthing systems Block 2: Harmonics Block 3: Voltage Variation Block 4: Power Quality Monitoring Two Round Tables will be organised: - Power quality and EMC in the Future Grid (CIGRE/CIRED WG C4.24, RT 13) - Reliability Benchmarking - why we should do it? What should be done in future? (RT 15

Integration of renewable energy sources in the distribution network

Tato práce uvádí obecné informace o obnovitelných zdrojích energie, typech elektráren a jejich pracovních principech. Práce je zaměřena na větrné elektrárny (principy, typy, komponenty, výhody a nevýhody). Obsahuje také pravidla pro připojování rozptýlených zdrojů energie k distribuční soustavě. V praktické části je řešena případová studie, která demonstruje napěťové charakteristiky pro síť vysokého napětí před a po připojení větrné elektrárny do distribuční sítě se dvěma různými hodnotami účiníku.This thesis will provide general information about renewable energy sources, types of power plants and their working principles. The thesis is focused on wind power plants (principles, types, components, advantages and disadvantages). It also includes the rules for connecting dispersed energy sources to the distribution system. In practical part, a case study demonstrates voltage characteristics before and after connection of a wind power plant to a distribution network with two different values of power factor