scholarly journals MODIFIED CAPACITOR ASSISTED EXTENDED BOOST QUASI Z-SOURCE INVERTER FOR THE GRID-CONNECTED PV SYSTEM

2019 ◽  
Vol 20 (1) ◽  
pp. 140-157
Author(s):  
N Hemalatha ◽  
Seyezhai Ramalingam
Keyword(s):  
Reactive Power ◽  
Fuzzy Controller ◽  
Single Stage ◽  
Control Technique ◽  
Duty Ratio ◽  
Grid System ◽  
Pv System ◽  
Power Injection ◽  
Three Phase ◽  
Boost Factor

A grid-tied, single stage, three phase, PV system provides higher efficiency than a two-stage PV system. This paper presents a three-phase, single stage, grid-connected PV system with MPPT and reactive power injection capability into the grid using modified capacitor assisted extended boost quasi Z-source inverter (MCAEB q-ZSI) as the grid-tied PV inverter. The adaptability of the inverter for irradiance changes and the boost factor control with its shoot-through duty ratio adjustment made it highly recommended for the grid system. The shoot-through control technique like maximum constant boost control with a third harmonic injection enhances the performance of the inverter by reducing the low order ripples and voltage stress. The fuzzy voltage controller is proposed with the capacitor linearization algorithm to regulate the DC-link voltage. The current approach uses a fuzzy controller to control the real and the reactive power injection into the grid. The performance evaluation of the fuzzy and PI grid controller is carried out for the constant irradiance condition and from the investigation, parameters like boost factor (B), the shoot-through duty ratio(Ds), real power (P), reactive power (Q),  power factor and harmonics in the current injection are determined. A laboratory setup of the PV powered grid system is implemented, tested and validated with the simulation results. ABSTRAK: Dalam sistem fotovoltaik (PV) yang bersambung dengan satu peringkat, satu sistem elektronik kuasa yang mempunyai keuntungan dan kecekapan yang tinggi diperlukan untuk menginterupasi dengan utiliti tersebut. Dalam makalah ini, kapasitor yang diubah suai dibantu oleh pemacu kuadratik Z-source yang dilanjutkan (MCAEB q-ZSI) bertindak sebagai unit interfacing antara PV dan grid. Penyesuaian penyongsang untuk perubahan sinaran dan kawalan faktor rangsangan dengan pelarasan nisbah tugas menembak membuatnya sangat disyorkan untuk sistem grid. Teknik kawalan menembak seperti kawalan rangsangan berterusan maksimum dengan suntikan harmonik ketiga meningkatkan prestasi penyongsang dengan mengurangkan aruhan pesanan rendah dan tekanan voltan. Pendekatan semasa menggunakan pengawal kabur untuk mengawal suntikan kuasa sebenar dan reaktif ke grid. Penilaian prestasi pengawal grid fuzzy dan PI dilakukan untuk keadaan iradiasi malar dan dari penyiasatan, parameter seperti faktor rangsangan (B), nisbah tugas menembak (Ds), kuasa nyata (P), kuasa reaktif Q), faktor kuasa dan harmonik dalam suntikan semasa ditentukan.   

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 A robust model-free controller for a three-phase grid-connected photovoltaic system based on ultra-local model

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Ahsene Boubakir ◽  
Sid-Ahmed Touil ◽  
Salim Labiod ◽  
Nasserdine Boudjerda
Keyword(s):  
Reactive Power ◽  
Photovoltaic System ◽  
Local Model ◽  
Control Technique ◽  
Pv System ◽  
Model Free ◽  
Robust Model ◽  
Three Phase ◽  
Output Behavior ◽  
Model Free Controller

AbstractIn this paper, a robust model-free controller for a grid-connected photovoltaic (PV) system is designed. The system consists of a PV generator connected to a three-phase grid by a DC/AC converter. The control objectives of the overall system are to extract maximum power from the PV source, to control reactive power exchange and to improve the quality of the current injected into the grid. The model-free control technique is based on the use of an ultra-local model instead of the dynamic model of the overall system. The local model is continuously updated based on a numerical differentiator using only the input–output behavior of the controlled system. The model-free controller consists of a classical feedback controller and a compensator for the effects of internal parameter changes and external disturbances. Simulation results illustrate the efficiency of the controller for grid-connected PV systems.

scholarly journals PV Based Grid System for Power Quality Enhancement using Instantaneous P-Q Theory

2019 ◽  
Vol 9 (1S6) ◽  
pp. 6-12
Keyword(s):  
Reactive Power ◽  
Pi Controller ◽  
Control Technique ◽  
Dynamic State ◽  
Grid System ◽  
Power Theory ◽  
Current Harmonic ◽  
Q Theory ◽  
Three Phase ◽  
Wire System

The SPV interfaced grid system with battery storage unit, bidirectional VSI interconnected shunt active filter, an adaptive Proportional Integral (PI) controller is employed for improve current and voltage profile enhancement. The p-q theory is the common employed technique to extract the basic fundamental current harmonic components from affected or polluted power supply by means of diode rectifier or non linear load. The basic concepts of reactive power (IRP) theory includes it’s a time domain model and it can be applicable for both 3P3W and 3P4W. Initially, the control technique called instantaneous real and reactive power theory or p-q theory has been developed for three phase three wire system and then later it was extend to three phase four wire system. This system is valid under steady state as well as dynamic state. The bidirectional VSI based shunt APF is controlled by the PI based instantaneous reactive power theory. The proposed PI Controller interfaced shunt Active Power Filter is used to maintain DC-Link voltage.SPV system is interfaced with incremental conductance MPPT algorithm. This SAPF control scheme has to provide the following benefits like current harmonic mitigation as well as reactive power compensation

scholarly journals Performance Enhancement of a Single-Stage CUK Based Three Phase Photovoltaic Inverter using Anfis Controller

2019 ◽  
Vol 8 (11) ◽  
pp. 2682-2688
Keyword(s):  
Performance Enhancement ◽  
Fuzzy Inference ◽  
Fuzzy Controller ◽  
Pi Controller ◽  
Single Stage ◽  
Pv System ◽  
Inference System ◽  
Pv Inverter ◽  
Three Phase ◽  
High Efficient

A modular structured and high efficient photovoltaic (PV) system is essential in today’s scenario. The single stage Cuk based inverter has continuous input and output current, and hence, makes it suitable for applying MPPT techniques when used for PV applications. The PI, PID, and fuzzy controllers could be applied for PV inverter. The PI controller decreases the error in steady state, and at the same time, it also decreases the stability of the system. The PID controller involves large time delay process. The random nature in fuzzy controller may not lead to optimum results. Hence, this paper proposes a controller based on Adaptive Neuro-Fuzzy Inference System (ANFIS) for a three phase PV inverter based on Cuk converter. The effectiveness of proposed system is verified using MATLAB/SIMULINK, and the results are presented. The performance of proposed ANFIS controller for Cuk based three phase inverter is compared with conventional PI controller. The proposed system has several merits like increased performance, accuracy, and efficiency.

scholarly journals Reactive Power Control of Single-Stage Three-Phase Photovoltaic System during Grid Faults Using Recurrent Fuzzy Cerebellar Model Articulation Neural Network

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Faa-Jeng Lin ◽  
Kuang-Chin Lu ◽  
Hsuan-Yu Lee
Keyword(s):  
Neural Network ◽  
Power Control ◽  
Reactive Power ◽  
Single Stage ◽  
Pv System ◽  
Reactive Power Control ◽  
Active And Reactive Power ◽  
Three Phase ◽  
Control Scheme ◽  
Reactive Current

This study presents a new active and reactive power control scheme for a single-stage three-phase grid-connected photovoltaic (PV) system during grid faults. The presented PV system utilizes a single-stage three-phase current-controlled voltage-source inverter to achieve the maximum power point tracking (MPPT) control of the PV panel with the function of low voltage ride through (LVRT). Moreover, a formula based on positive sequence voltage for evaluating the percentage of voltage sag is derived to determine the ratio of the injected reactive current to satisfy the LVRT regulations. To reduce the risk of overcurrent during LVRT operation, a current limit is predefined for the injection of reactive current. Furthermore, the control of active and reactive power is designed using a two-dimensional recurrent fuzzy cerebellar model articulation neural network (2D-RFCMANN). In addition, the online learning laws of 2D-RFCMANN are derived according to gradient descent method with varied learning-rate coefficients for network parameters to assure the convergence of the tracking error. Finally, some experimental tests are realized to validate the effectiveness of the proposed control scheme.

scholarly journals Decoupled Control of Three Phase Grid Connected Solar PV System

2019 ◽  
Vol 9 (2) ◽  
pp. 4218-4222
Keyword(s):  
Solar Energy ◽  
Power Factor ◽  
Control Strategy ◽  
Reactive Power ◽  
Standard Test ◽  
Effective Control ◽  
Solar Pv ◽  
Pv System ◽  
Three Phase ◽  
Decoupled Control

A reliable grid connected Photovoltaic (PV) system require effective control schemes for efficient use of solar energy. This paper presents a three-phase grid tied PV system with decoupled real and reactive power control to achieve desired power factor with Maximum Power Point Tracking (MPPT) controller to get maximum solar energy. The synchronous reference frame (dq) control along with decoupling concept is used to control the DC-AC inverter output, while the Phase Locked Loop (PLL) synchronization technique is used to monitor and synchronize the voltage and current at the grid side. The DC-DC converter with Incremental Conductance (InC) based MPPT model is also designed in this paper due to better accuracy compared to Perturb & Observe (P&O) algorithm. The simulation is performed in MATLAB/SIMULINK and a 31.5 kW PV system is modelled to get 30 kW power with the help of MPPT at Standard Test Conditions (STC). Any power factor value between 0.85 lagging to 0.9 leading can be obtained by changingreference q current in this inverter control strategy. The simulation results show that the change of reactive powerdoes not affecttheactive power values of the system, which verifies the effectiveness of the decoupled control strategy of the inverter.

scholarly journals High Performance Multistring Converter Topology for Three-Phase Grid Tied 200 kW Photovoltaic Generating System

2017 ◽  
Vol 1 (2) ◽  
Author(s):  
Mohammad Rustam M. L. ◽  
F. Danang Wijaya
Keyword(s):  
Power Efficiency ◽  
High Performance ◽  
Reactive Power ◽  
Simulation Method ◽  
Operating Conditions ◽  
Total System ◽  
Voltage Reference ◽  
Pv System ◽  
Three Phase ◽  
Converter Topology

Under various external conditions, grid connected PV system performance is strongly affected by the topology that is used to connect a PV system with grid. This research aims to design a multistring based converter topology for three-phase grid connected 200 kW PV system that has a high performance in various operating conditions. Research was done by a simulation method using Matlab-Simulink with performance being evaluated including the generated power, efficiency, power quality in accordance with grid requirements, as well as the power flow. In the simulation, multistring converter topology was designed using two dc-dc boost multistring converters connected in parallel to a centralized of three-phase three-level NPC inverter with the size of the string being shorter and more parallel strings as well as the maximum voltage of the PV array of 273.5 V close to dc voltage reference of 500 V. Each dc-dc boost multistring converter have individual MPPT controllers. The simulation results showed that this multistring converter topology had a high performance in various operating conditions. This due to more power generated by the NPC inverter (> 190 kW) at the time of high power generation on the STC conditions (1000 W/m2, 25 oC), the lowest efficiency of the total system is 95.08 % and the highest efficiency of the total system is 99.4 %, the quality of the power generated in accordance with the requirements of grid, as well as the inverter put more active power to the grid and less reactive power to the grid. The response of the inverter slightly worse for loads with greater reactive power and unbalanced.

Sign in / Sign up

Export Citation Format

Share Document