scholarly journals DC-Link Capacitor Diagnosis in a Single-Phase Grid-Connected PV System

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6754
Author(s):  
Ramiro Alejandro Plazas-Rosas ◽  
Martha Lucia Orozco-Gutierrez ◽  
Giovanni Spagnuolo ◽  
Édinson Franco-Mejía ◽  
Giovanni Petrone
Keyword(s):  
Single Phase ◽  
Electrochemical Impedance ◽  
Operating Conditions ◽  
Voltage Source ◽  
Equivalent Series Resistance ◽  
Pv System ◽  
Voltage Source Inverters ◽  
Fitting Algorithm ◽  
Impedance Curve ◽  
Power Point

The DC-link capacitor is one of the components that are more prone to faults in energy-distributed systems based on voltage source inverters. A predictive maintenance approach should allow to foresee the risk of an unexpected system shutdown. In this study, a two-stage diagnostic approach that is aimed at determining the health status of the DC-link capacitor in a single-phase grid-connected PV system was proposed. The equivalent series resistance (ESR) and the capacitance (C) values were used as indicators in the estimation of the degradation stage. Electrochemical impedance spectroscopy (EIS) was used to estimate the impedance curve of the DC-link capacitor, and a multi-fitting algorithm allowed us to determine the ESR and C parameters. A comparison between the estimated values C and ESR and the nominal values was used to quantify the fault severity. It was demonstrated that the EIS allowed the determination of the capacitor impedance regardless of the actual operating conditions of the photovoltaic generator, such as during irradiance changes and with the maximum power point algorithm turned off. By using the capacitor simplified model and a multi-fitting algorithm, the C and ESR values were estimated with an error that was lower than 1%. An analysis of the hardware required to implement the proposed approach in real applications by achieving the desired accuracy was also proposed.

scholarly journals A Single Phase Grid Connected PV System working in Different Modes

2020 ◽  
Vol 10 (5) ◽  
pp. 6374-6379
Author(s):  
P. S. Gotekar ◽  
S. P. Muley ◽  
D. P. Kothari
Keyword(s):  
Single Phase ◽  
Operating Conditions ◽  
Voltage Profile ◽  
Pv System ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Current Controller ◽  
Stable Conditions ◽  
Point Of Common Coupling ◽  
Power Point

The current grid standards for the single-phase residential PV system expect it to operate at Maximum Power Point Tracking (MPPT) mode under normal operating conditions and to maintain the voltage profile whenever a grid fault occurs. The proposed system supplies power to the load under stable conditions and the PV system works in MPPT mode. When the fault occurs at the Point of Common Coupling (PCC) and the voltage is reduced, the proposed controller maintains the voltage profile by injecting the current fed by the current controller at the PCC. The controller shifts from MPPT to the faulty mode and maintains voltage as per grid requirements. During islanding conditions, the PV system successfully caters to the requirements of the load by shifting the control from MPPT to islanding mode. When the PV system is in operation the power quality is enhanced

A Structural-Algorithmic and Parametric Synthesis of Single-Phase Voltage Source Inverters for Increased Power Capacity

2021 ◽  
Vol 2 (2) ◽  
pp. 44-53
Author(s):  
GENNADY S. MYTSYK ◽  
◽  
ZAW HTET HEIN ◽  
Keyword(s):  
Energy Flow ◽  
Output Voltage ◽  
Power Plants ◽  
Single Phase ◽  
Voltage Source ◽  
Phase Voltage ◽  
Power Capacity ◽  
Voltage Source Inverters ◽  
Solar Power Plants ◽  
Output Filter

The recent interest of developers of new technology in studying a structural and algorithmic synthesis (SAS) of voltage source inverters (VSI) for solar power plants (SPP) is stemming from a growing need to solve problems in connection with the revealed new possibilities of converting energy flow (from DC to AC) with better energy efficiency by reducing the depth of its pulse modulation. This problem is solved by using more rational structural and algorithmic solutions. It is shown that for SPPs for a capacity of about 1 MW and more, it is more expedient to construct inverters based on the energy flow multichannel conversion principle. Given a limited power capacity of the transistor components, the application of this principle allows the problem to be solved in fact without using an output filter. The output voltage waveform is shaped using the energy flow pulse-amplitude modulation (PAM), and its M parts are summed in the output circuit by out using M winding transfilters (M-TF). The proposed method for carrying out combined SAS of single-phase voltage source inverters with multichannel conversion is considered, which consists in using an N-level single-phase VSI (N-SPVSI) in each of the M channels with the voltage levels optimized in terms of the minimum total harmonic distortion (THD). The resulting voltage of this class of single-phase inverters, designated as MxN-SPVSI, is formed by the corresponding phase shift of the channel voltages followed by summing the channel currents by M-TF. It is shown that the resulting output voltage levels are also close to their values optimized with respect to the minimum of the THD indicator. The results from a comparative analysis of two options — a single-channel 8-level inverter and a four-channel 8-level inverter are given. For the second option, only one intermediate voltage tap in the solar battery is required (instead of seven taps in the first option) along with modern transistor components that are available for practical implementation. In both options, the THD value less than 5% is obtained with almost no need of using an output filter. The presented results provide a certain information and methodological support for system designing of single-phase voltage source inverters as applied to the specific features of solar power plants. Three-phase inverters can be built on the basis of three single-phase inverters with galvanic isolation of the power sources for each phase.

scholarly journals Hybrid Fuzzy Based MPPT Techniques for Maximum Power Extraction

2019 ◽  
Vol 8 (2S8) ◽  
pp. 1140-1148
Keyword(s):  
Maximum Power ◽  
Photovoltaic System ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Pv System ◽  
Power Extraction ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Incremental Conductance ◽  
Power Point

The extensive usage of solar has extended the opportunity of research to increase the efficiency of PV module. Maximum Power Point Tracking technique plays an important role. In P & O and Incremental conductance the power produced is less. In this paper a Fuzzy based P & O and Fuzzy based Incremental Conductance MPPT techniques are presented to extract the maximum power from the photovoltaic system by considering the dynamic variation in irradiations and temperature also. Here the 100 kW PV array is considered and it is connected to the utility grid via a DC-DC boost converter of 500volts with a 3 phase three level voltage source converter. The result is obtained by the MAT LAB Simulink and the same is appraised with the traditional P & O and Incremental conductance. The PV System produces the maximum power by the application of Fuzzy based incremental Technique compared to conventional methods.

scholarly journals ICM based ANFIS MPPT controller for grid connected photovoltaic system

2018 ◽  
Vol 7 (3) ◽  
pp. 1508 ◽  
Author(s):  
R Pavan Kumar Naidu ◽  
S Meikandasivam
Keyword(s):  
Boost Converter ◽  
Photovoltaic System ◽  
Voltage Source ◽  
Photovoltaic Module ◽  
Voltage Source Inverter ◽  
Pv System ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Conductance Method ◽  
Power Point

In this paper, grid-connected photovoltaic (PV) system is presented. PV system consists of a photovoltaic module, a boost converter, and voltage source inverter. ANFIS based ICM (Incremental Conductance Method) MPPT (Maximum Power Point Tracking) controller is utilized to produce gate signal for DC-DC boost converter. This controller is used for optimizing the total performance of the Photovoltaic system in turn the errors were reduced in Voltage Source Inverter (VSI). The grid-connected PV system performance is evaluated and har-monics occurred in the system are decreased. The proposed methodology is implemented in MATLAB/Simulink. 

scholarly journals Fuzzy Logic Control for Low-Voltage Ride-Through Single-Phase Grid-Connected PV Inverter

Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4796 ◽  
Author(s):  
Eyad Radwan ◽  
Mutasim Nour ◽  
Emad Awada ◽  
Ali Baniyounes
Keyword(s):  
Fuzzy Logic ◽  
Output Power ◽  
Single Phase ◽  
Reactive Power ◽  
Low Voltage ◽  
Operating Conditions ◽  
Pv System ◽  
Utilization Factor ◽  
Low Voltage Ride Through ◽  
Active And Reactive Power

This paper presents a control scheme for a photovoltaic (PV) system that uses a single-phase grid-connected inverter with low-voltage ride-through (LVRT) capability. In this scheme, two PI regulators are used to adjust the power angle and voltage modulation index of the inverter; therefore, controlling the inverter’s active and reactive output power, respectively. A fuzzy logic controller (FLC) is also implemented to manage the inverter’s operation during the LVRT operation. The FLC adjusts (or de-rates) the inverter’s reference active and reactive power commands based on the grid voltage sag and the power available from the PV system. Therefore, the inverter operation has been divided into two modes: (i) Maximum power point tracking (MPPT) during the normal operating conditions of the grid, and (ii) LVRT support when the grid is operating under faulty conditions. In the LVRT mode, the de-rating of the inverter active output power allows for injection of some reactive power, hence providing voltage support to the grid and enhancing the utilization factor of the inverter’s capacity. The proposed system was modelled and simulated using MATLAB Simulink. The simulation results showed good system performance in response to changes in reference power command, and in adjusting the amount of active and reactive power injected into the grid.

Daily Constant PV Output Power Supplying AC pumps using Batteries

2016 ◽  
Vol 2 (2) ◽  
pp. 275
Author(s):  
Mohamed Mahmoud Ismail
Keyword(s):  
Output Power ◽  
Boost Converter ◽  
Operating Conditions ◽  
Voltage Source ◽  
Maximum Power Point ◽  
Pv Array ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Three Phase ◽  
Power Point

This paper presents 200 KW three phase standalone photovoltaic systems supplying pumping station consist of four pumps 40 KW rating. The system utilizes a two stage energy conversion power conditioning unit topology composed of a DC-DC boost converter and three level-three phase voltage source inverter (VSI). The Boost converter in this paper is designed to operate in continuous mode and controlled for maximum power point tracking (MPPT). The fluctuating output power of the PV array system during the day is the commonly problem in the power system.  In this paper a nickel-Cadmium battery will be used to maintain the output power generated from the PV array supplying the pumps to be constant all the day under different operating conditions. The system is modeled and studied using MATLAB/Simulink

scholarly journals HIL-Assessed Fast and Accurate Single-Phase Power Calculation Algorithm for Voltage Source Inverters Supplying to High Total Demand Distortion Nonlinear Loads

Electronics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1643
Author(s):  
Jorge El Mariachet ◽  
Yajuan Guan ◽  
Jose Matas ◽  
Helena Martín ◽  
Mingshen Li ◽  
...  
Keyword(s):  
Steady State ◽  
Single Phase ◽  
Reactive Power ◽  
Dynamic Performance ◽  
Active Power ◽  
Voltage Source ◽  
Power Calculation ◽  
Calculation Algorithm ◽  
Nonlinear Loads ◽  
Voltage Source Inverters

The dynamic performance of the local control of single-phase voltage source inverters (VSIs) can be degraded when supplying to nonlinear loads (NLLs) in microgrids. When this control is based on the droop principles, a proper calculation of the active and reactive averaged powers (P–Q) is essential for a proficient dynamic response against abrupt NLL changes. In this work, a VSI supplying to an NLL was studied, focusing the attention on the P–Q calculation stage. This stage first generated the direct and in-quadrature signals from the measured load current through a second-order generalized integrator (SOGI). Then, the instantaneous power quantities were obtained by multiplying each filtered current by the output voltage, and filtered later by utilizing a SOGI to acquire the averaged P–Q parameters. The proposed algorithm was compared with previous proposals, while keeping the active power steady-state ripple constant, which resulted in a faster calculation of the averaged active power. In this case, the steady-state averaged reactive power presented less ripple than the best proposal to which it was compared. When reducing the velocity of the proposed algorithm for the active power, it also showed a reduction in its steady-state ripple. Simulations, hardware-in-the-loop, and experimental tests were carried out to verify the effectiveness of the proposal.

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