scholarly journals New control scheme for synchronizationof a photovoltaic system to a three-phase grid to attenuate the harmonics of currents caused by distorted grid voltage

2020 ◽  
Vol 9 (3) ◽  
pp. 256
Author(s):  
Ismail Boukhechem ◽  
Ahcen Boukadoum ◽  
Lahcene Boukelkoul ◽  
Houssam Eddine Medouce ◽  
Rima Lebied
Keyword(s):  
Photovoltaic System ◽  
Pv System ◽  
Grid Voltage ◽  
Voltage Sensors ◽  
Distorted Grid ◽  
Three Phase ◽  
Control Scheme ◽  
Self Tuning ◽  
A New Technique ◽  
Virtual Flux

<div data-canvas-width="397.43840959483975">This study presents a new scheme of control for the synchronization of a photovoltaic (PV) system with a three-phase grid without a line sensor. The approach of the proposed synchronization technique is developed to extract the</div><div>maximum of PV energy and inject it in the network for various conditions of voltage, and to ensure that the currents injected into the three-phase network emulate the wished sinusoidal forms even when the mains grid voltage is no longer ideal. This paper in troduces a new technique of synchronization and elimination of the disturbances created by the distorted tension based on the direct power control without voltage sensors (VF_DPC) with the help of second-order generalized integrator (SOGI) associated with a self-tuning filter(STF) to extract the fundamental virtual flux. The simulation of the proposed system is realized in MATLAB/Simulink environment.</div>

scholarly journals New Pulse Width Modulation Technique to Reduce Losses for Three-Phase Photovoltaic Inverters

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Mohannad Jabbar Mnati ◽  
Dimitar V. Bozalakov ◽  
Alex Van den Bossche
Keyword(s):  
Control Strategy ◽  
Pulse Width Modulation ◽  
Photovoltaic System ◽  
Pv System ◽  
Total Cost ◽  
Switching Losses ◽  
Three Phase ◽  
Operational Lifetime ◽  
Term Energy ◽  
Dc Bus

Nowadays, most three-phase, “off the shelf” inverters use electrolytic capacitors at the DC bus to provide short term energy storage. However, this has a direct impact on inverter lifetime and the total cost of the photovoltaic system. This article proposes a novel control strategy called a 120° bus clamped PWM (120BCM). The 120BCM modulates the DC bus and uses a smaller DC bus capacitor value, which is typical for film capacitors. Hence, the inverter lifetime can be increased up to the operational lifetime of the photovoltaic panels. Thus, the total cost of ownership of the PV system will decrease significantly. Furthermore, the proposed 120BCM control strategy modulates only one phase current at a time by using only one leg to perform the modulation. As a result, switching losses are significantly reduced. The full system setup is designed and presented in this paper with some practical results.

scholarly journals Modeling and Design of the Vector Control for a Three-Phase Single-Stage Grid-Connected PV System with LVRT Capability according to the Spanish Grid Code

Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2899 ◽  
Author(s):  
Alexis B. Rey-Boué ◽  
N. F. Guerrero-Rodríguez ◽  
Johannes Stöckl ◽  
Thomas I. Strasser
Keyword(s):  
Vector Control ◽  
Reactive Power ◽  
Low Voltage ◽  
Single Stage ◽  
Photovoltaic System ◽  
Lookup Table ◽  
Voltage Sags ◽  
Pv System ◽  
Low Voltage Ride Through ◽  
Three Phase

This article deals with the vector control in dq axes of a three-phase grid-connected photovoltaic system with single-stage topology and low-voltage-ride-through capability. The photovoltaic generator is built using an array of several series-parallel Suntech PV modules and is modeled as a Lookup Table (two-dimensional; 2-D). The requirements adopted when grid voltage sags occur are based in both the IEC 61400-21 European normative and the allowed amount of reactive power to be delivered according to the Spanish grid code, which avoids the disconnection of the inverter under grid faults by a limitation in the magnitude of the three-phase output inverter currents. For this, the calculation of the positive- and negative-sequences of the grid voltages is made and a conventional three-phase Phase-Locked Loop is used for the inverter-grid synchronization, allowing the control of the active and reactive powers solely with the dq components of the inverter currents. A detailed enhanced flowchart of the control algorithm with low-voltage-ride-through capability is presented and several simulations and experiments using Matlab/SIMULINK and the Controller Hardware-in-the-Loop simulation technique, respectively, are run for several types of one- and three-phase voltage sags in order to validate its behavior.

scholarly journals Improvement of DSOGI PLL Synchronization Algorithm with Filter on Three-Phase Grid-connected Photovoltaic System

2018 ◽  
Vol 18 (1) ◽  
pp. 35 ◽  
Author(s):  
Rofiatul Izah ◽  
Subiyanto Subiyanto ◽  
Dhidik Prastiyanto
Keyword(s):  
Reference Frame ◽  
Frequency Estimation ◽  
Photovoltaic System ◽  
Positive Sequence ◽  
Pv System ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Synchronous Reference Frame ◽  
Three Phase ◽  
Low Pass

Synchronous Reference Frame Phase Locked Loop (SRF PLL) has been widely used for synchronization three-phase grid-connected photovoltaic (PV) system. On the grid fault, SRF PLL distorted by negative sequence component and grid harmonic that caused an error in estimating parameter because of ripple and oscillation. This work combined SRF PLL with Dual Second Order Generalized Integrator (DSOGI) and filter to minimize ripple and minimize oscillation in the phase estimation and frequency estimation. DSOGI was used for filtering and obtaining the 90o shifted versions from the vαβ signals. These signals (vαβ) were generated from three phase grid voltage signal using Clarke transform. The vαβ signal was the inputs to the positive-sequence calculator (PSC). The positive-sequence vαβ was transformed to the dq synchronous reference frame and became an input to SRF-PLL to create the estimation frequency. This estimation frequency from SRF PLL was filtered by the low-pass filter to decrease grid harmonic. Moreover, the output of low-pass filter was a frequency adaptive. The performance of DSOGI PLL with filter is compared with DSOGI PLL, SRF PLL, and IEEE standard 1547(TM)-2003. The improvement of DSOGI PLL with filter gave better performances than DSOGI PLL and SRF PLLbecause it minimized ripples and oscillations in the phase and frequency estimations.

Transient and Steady State Analysis of Modified Three Phase Multilevel Inverter for Photovoltaic System

2017 ◽  
Vol 8 (1) ◽  
pp. 31 ◽  
Author(s):  
M. Venkatesan ◽  
R. Rajeswari ◽  
M. Kaliyamoorthy ◽  
M. Srithar
Keyword(s):  
Steady State ◽  
Fuzzy Logic Controller ◽  
Multilevel Inverter ◽  
Photovoltaic System ◽  
Pv System ◽  
Steady State Analysis ◽  
Semiconductor Switches ◽  
Three Phase ◽  
Transient And Steady State ◽  
State Analysis

The transient and steady state analysis of Modified Three Phase Multilevel Inverter (MMLI) for Photovoltaic (PV) system fed from single DC input is presented in this paper. The transient and Steady state conditions of modified three phase multilevel inverter are analyzed using Proportional Integral (PI) and Fuzzy Logic Controller (FLC) with change in irradiance level of PV panels. The three phase multilevel inverter  is designed with reduce number of power semiconductor switches, components, single DC input and effectively controlled by using Space Vector Pulse width Modulation technique (SVPWM).  The obtained results are validated using MATLAB/ Simulink.Finaly, semiconductor switches and componets utilization of MMLI is compared with other similar topologies.

scholarly journals Design of a Proportional Resonant Controller with Resonant Harmonic Compensator and Fault Ride Trough Strategies for a Grid-Connected Photovoltaic System

Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 451 ◽  
Author(s):  
Saif Islam ◽  
Kamran Zeb ◽  
Waqar Din ◽  
Imran Khan ◽  
Muhammad Ishfaq ◽  
...  
Keyword(s):  
Fault Location ◽  
Photovoltaic System ◽  
Pv System ◽  
Simulink Model ◽  
Fault Ride Through ◽  
Three Phase ◽  
Point Of Common Coupling ◽  
Switch Type ◽  
Resonant Controller ◽  
Common Coupling

This paper presents the design and analysis of a proportional resonant controller with a resonant harmonic compensator and switch-type fault current limiter, as a fault-ride through strategy for a three-phase, grid-connected photovoltaic (PV) system under normal conditions and asymmetrical faults. The switch-type fault limiter comprised of current-limiting inductors, a bridge rectifier, a snubber capacitor, linear transformers, and energy absorption bypass. Furthermore, a critical and analytical comparison of switch-type fault limiters is carried out, with the conventional crowbar as the fault-ride through strategy, in combination with a conventionally tuned proportional integrator controller. The designed fault-ride through strategies with proportional integrator and proportional resonant controllers with resonant harmonic compensators are tested at the point of common coupling of the photovoltaic system and at a distance of 19 km from the point of common coupling, in order to analyze the impacts of fault parameter with respect to location. A MATLAB/Simulink model of a 100 kW three-phase grid-connected photovoltaic system is used for analysis. The simulation results of the proposed switch-type fault limiter with proportional resonant controller effectively validate the stable, ripple-free, and robust response compared to all other configurations. In addition, it is also verified that the grid faults on the PV system have a significant impact on fault type, and less impact on fault location.

scholarly journals Enhanced Control Scheme for a Three-Phase Grid-Connected PV Inverter under Unbalanced Fault Conditions

Electronics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1247
Author(s):  
Saeid Abbasi ◽  
Ali Asghar Ghadimi ◽  
Amir Hossein Abolmasoumi ◽  
Mohammad Reza Miveh ◽  
Francisco Jurado
Keyword(s):  
Reactive Power ◽  
Control Strategies ◽  
Active Power ◽  
Reactive Control ◽  
Pv System ◽  
Pv Inverter ◽  
Three Phase ◽  
Control Scheme ◽  
Double Grid ◽  
Unbalanced Grid

This paper presents an improved control strategy to cancel the double grid frequency oscillations in the active power, reactive power, and DC-link voltage of a three-phase grid-connected photovoltaic (PV) system under unbalanced grid condition. To achieve these goals, an enhanced positive–negative-sequence control (PNSC) to remove oscillations of active power and an instantaneous active–reactive control (IARC) to mitigate the fluctuations of active and reactive power, simultaneously, are suggested. These methods are also effective to reduce the oscillations of the DC-link voltage. To track the desired unbalanced or harmonic reference currents, improved proportional resonant (PR) current controllers have been designed using the Bode frequency analysis. Simulation studies are carried out via Matlab/Simulink® software to verify the effectiveness of the suggested control strategies.

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