This paper deals with a comprehensive study of configurations of microgrid (MG) based on variable speed generators. The selection criteria for these configurations along with the design of required ...control algorithms, are presented in detail. Simulation results and experimental validation of selected MG configurations are given to demonstrate their suitability. It is aimed to enhance applications of MGs with main emphasis on renewable energy sources to ensure sustainable development in rural and remote areas.
The modelling of photovoltaic (PV) solar cells using a hybrid adaptive neuro-fuzzy inference system (ANFIS) algorithm is presented. It is based on the decomposition of the cell output current into ...photocurrent and junction current. The photocurrent is linearly dependent on solar irradiance and cell temperature; consequently, its analytical computation is done easily. However, the junction current is highly non-linear and depends on cell voltage and temperature. Therefore, its analytical computation is complicated and the manufacturers do not supply any information about this parameter. Moreover, there is no way to measure it physically. Therefore, it is proposed to use the ANFIS algorithm as a powerful technique in order to estimate this current and reconstruct the output PV cell current using the photocurrent. The model validation is based on the gradient descent and chain rule applied to a set of data different than the one used for training process. The advantage of the proposed model is that only one climatic parameter is used as the input to the ANFIS algorithm, which makes it less sensitive to climatic variations.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Renewable energy resources (RES) are being increasingly connected in distribution systems utilizing power electronic converters. This paper presents a novel control strategy for achieving maximum ...benefits from these grid-interfacing inverters when installed in 3-phase 4-wire distribution systems. The inverter is controlled to perform as a multi-function device by incorporating active power filter functionality. The inverter can thus be utilized as: 1) power converter to inject power generated from RES to the grid, and 2) shunt APF to compensate current unbalance, load current harmonics, load reactive power demand and load neutral current. All of these functions may be accomplished either individually or simultaneously. With such a control, the combination of grid-interfacing inverter and the 3-phase 4-wire linear/non-linear unbalanced load at point of common coupling appears as balanced linear load to the grid. This new control concept is demonstrated with extensive MATLAB/Simulink simulation studies and validated through digital signal processor-based laboratory experimental results.
Power electronics plays an important role in controlling the grid-connected renewable energy sources. This paper presents a novel adaptive neuro-fuzzy control approach for the renewable interfacing ...inverter. The main objective is to achieve smooth bidirectional power flow and nonlinear unbalanced load compensation simultaneously, where the conventional proportional-integral controller may fail due to the rapid change in the dynamics of the highly nonlinear system. The combined capability of neuro-fuzzy controller in handling the uncertainties and learning from the processes is proved to be advantageous while controlling the inverter under fluctuating operating conditions. The inverter is actively controlled to compensate the harmonics, reactive power, and the current imbalance of a three-phase four-wire (3P4W) nonlinear load with generated renewable power injection into the grid simultaneously. This enables the grid to always supply/absorb a balanced set of fundamental currents at unity power factor even in the presence of the 3P4W nonlinear unbalanced load at the point of common coupling. The proposed system is developed and simulated in MATLAB/SimPowerSystem environment under different operating conditions. The digital signal processing and control engineering-based laboratory experimental results are also provided to validate the proposed control approach.
This paper presents the experimental implementation of a LMS-Adaline-based ANFIS controller of an improved power-quality photovoltaic (PV) generating system connected to the grid. The proposed system ...applies an adaptive neuro-fuzzy inference system (ANFIS) to control the DC–DC boost converter integrated with PV to achieve the maximum power point tracking (MPPT) operating condition. For power-quality improvement at the point of common coupling (PCC), Adaline (adaptive linear element)-based control algorithm is used to estimate the reference grid currents. To achieve high performance with fast dynamic response during transition and to regulate constant the DC and the AC voltages without saturation phenomena, ANFIS controller is employed. The real-time benchmark realised in the laboratory, to implement the setup, uses a dSPACE controller. To demonstrate the performance of the proposed configuration, the system is first simulated offline under numerous critical scenarios. The experimental results are then presented to validate the concept.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Control of Single-Phase Solar Photovoltaic Supply System Pardhi, Pemendra Kumar; Sharma, Shailendra Kumar; Chandra, Ambrish
IEEE transactions on industry applications,
2020-Nov.-Dec., 2020-11-00, Volume:
56, Issue:
6
Journal Article
Peer reviewed
This article presents the modeling, design, and control of a photovoltaic supply (PVS) for single-phase grid system. In the two stage conversion process, a step-up converter (SUC) is employed in ...between the photovoltaic panel and dc bus of voltage source converter (VSC). For the maximum power tracking (MPT) at PVS terminals, a fuzzy logic control (FLC) based approach is developed for the switching of an SUC. A band-pass filter (BPF) is developed using modified multilayer fifth-order generalized integrator (mMLFOGI) to estimate synchronizing signals of the grid supply for the control of VSC. The mMLFOGI based BPF ensures the proper synchronization of VSC under grid disturbances such as dc offsets, frequency variations, voltage sag, swell, and harmonics. These proposed control approaches are simulated in MATLAB 2018a and prototype of PVS for single-phase grid system is developed in the laboratory. A Texas instrument micro controller board TMS320F28379D is used for real time validations of proposed control algorithms. The performance is obtained using simulation model and validated with test results under field emulated conditions.
This paper introduces a novel efficient finite control-set model predictive control (EFCS-MPC) method with a single closed-loop control objective for various multilevel packed U-cell (PUC) inverter ...topologies. By employing the available redundancies of a PUC inverter switching combinations, the proposed EFCS-MPC integrates flying capacitors' voltage regulation into the optimization process rather than the cost function. Therefore, considering the selection of a suitable switching state at each sampling time, in addition to having a minimized cost function, an intuitive control algorithm regarding the measured voltages of capacitors is also designed and considered as a benchmark. The introduced EFCS-MPC has several merits such as significantly reduced computational burden without requiring weighting factors selection as well as reliable steady-state and transient performance. These features make this hybrid control method an attractive option especially for industrial applications of PUC-based inverters. Extensive simulation results and analysis are also presented to demonstrate the operation of the proposed EFCS-MPC.
This paper presents a novel algorithm based on polynomial approximations (PAs) for an efficient error compensation of magnetic analog encoders (MAEs) in permanent-magnet synchronous machines (PMSMs) ...intended for electric vehicle (EV) propulsion. The proposed PA algorithm requires a negligible memory space compared to a very high-resolution look-up table (LUT). The use of polynomials allows compensating every possible input rotor position without carrying out an interpolation or a rounding to the nearest quantized value. The PA algorithm has been implemented to work in real time on a TM4 EV drive controlling an 80 kW PMSM. The performance of the algorithm has been validated at 6000 and 9000 r/min under +85 and ±55 Nm of torque, respectively. The electromagnetic interference (EMI) effects have been minimized using a type-2 phase-locked loop (PLL). The proposed PA algorithm assisted with the PLL is capable of reducing the total position error to a range as small as ±0.2°. The combination of these two algorithms is a promising solution for compensating the position error in quadrature analog encoders. The experimental results obtained with the 80 kW PMSM demonstrate the feasibility of low-cost MAEs for achieving high-performance field-oriented control (FOC) of PMSMs in EV drives.
•This paper deals with a grid-integrated single phase solar photovoltaic system (GISPSPS) employed with a single switched based high gain boost converter. The significant contributions in this paper ...are;•The dynamic model of HGBC including effective series resistance (ESR) of passive elements is developed for improving accuracy with slight increase in complexity of model. Then its stability analysis is carried out under different solar irradiations (i.e. 300, 500, 800 and 1000 W/m2) using an eigenvalue plot.•The HGBC control is obtained using the sliding mode control (SMC) for PPE under change in solar irradiations. In proposed SMC only two sensing signals PV panel voltage and current (i.e. vpv and ipv) are needed for PPE in comparison to three sensing signals PV panel voltage, current and DC link voltage (i.e. vpv, ipv and vdc) require in SMC of ref. 10.•The control of FBVSC is obtained by a FiOGI controller. The FiOGI provides noise-less extraction of synchronization signal, under presence of DC offset and noise in grid voltage. However, FOGI used in ref. 10 exhibits poor performance under presence of noise in grid supply voltage.
This paper presents a grid-integrated single phase solar photovoltaic (PV) system (GISPSPS) with its modeling, design and control. The GISPSPS consists of a single switch based high gain boost converter (HGBC) and full bridge voltage source converter (FBVSC). The HGBC, boost the low PV panel voltage and extracts the optimum PV power. The HGBC allows high voltage conversion ratio and possesses less voltage stresses on power devices. The optimum PV power is extracted via a sliding mode control (SMC) strategy that generates the switching signal for the switch of HGBC. The FBVSC delivers PV power to the single phase utility grid, as well as load connected at point of interfacing (POI). A fifth order generalized integrator (FiOGI) is developed for FBVSC control to ensure harmonic suppression and DC offset rejection capability during extraction of fundamental grid voltage. Experimental validation of proposed GISPSPS and its control is also verified.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this paper, a comprehensive controller of a standalone microgrid is implemented, which has three dispersed generation units based on a wind, solar photovoltaic (PV) array, and a diesel generator ...(DG). The power ratio variable step perturb and observe method is applied to achieve maximum power point tracking of a solar PV array and a variable speed wind turbine coupled a permanent magnet brushless dc generator without rotor/wind speed sensors. Moreover, to ensure perfect synchronization of a DG to the point of common coupling (PCC), a control algorithm is developed, which is based on in-phase and quadrature units. An active power control based on proportional-integral controller with anti-windup, is used for voltage and frequency regulation. The LCL filter based on virtual resistor, is used for power quality improvement at PCC. Simulation and test results are presented for the validation of the proposed system using a prototype of 2 kW in the laboratory.
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