Performance of Multifunctional Smart PV-Based Domestic Distributed Generator in Dual-Mode Operation

This article briefs about a smart multifunctional single-phase inverter control for a domestic solar photo voltaic (PV)-based distributed generation that can work in both a grid-connected mode and an islanded mode by making the inverter mimic the operation of a synchronous generator. The control objectives were threefold: to provide the required active and reactive power for normal operating conditions and under varying operating conditions, to maintain the rated voltage and the rated frequency for the islanded mode, and to switch between the two modes of operation with the least amount of disturbance for the system while behaving as a virtual synchronous generator (VSG). The control structure is divided into three major loops: the outermost loop responsible for power control, the middle loop responsible for voltage control, and the innermost loop responsible for current control. The proposed control methodology incorporates the functionalities of the grid-connected and the islanded-mode control into a single complex structure and thus provides support to the grid under abnormal conditions while providing good-quality power to consumers under grid failure. The efficacy of the system is good. The operation under various modes were simulated in MATLAB Simulink, and the proportional integral (PI) controllers used for current controllers were tuned using particle swarm optimization (PSO). It can be concluded that the control structure becoming complex is benefitted by the added advantages of the smart PV system. The smart domestic PV system helps the prosumer to actively provide frequency support and voltage support, adding frequency support to the existing multifunctional PV systems.

Download Full-text

Adaptive SRF-PLL Based Voltage and Frequency Control of Hybrid Standalone WECS with PMSG-BESS

International Journal of Emerging Electric Power Systems ◽

10.1515/ijeeps-2018-0072 ◽

2018 ◽

Vol 19 (6) ◽

Cited By ~ 1

Author(s):

Anjana Jain ◽

R. Saravanakumar ◽

S. Shankar ◽

V. Vanitha

Keyword(s):

Reactive Power ◽

Frequency Control ◽

Storage System ◽

Synchronous Generator ◽

Energy Storage System ◽

Voltage Regulation ◽

Operating Conditions ◽

Voltage Source ◽

Voltage Source Converter ◽

Control Scheme

Abstract The variable-speed Permanent Magnet Synchronous Generator (PMSG) based Wind Energy Conversion System (WECS) attracts the maximum power from wind, but voltage-regulation and frequency-control of the system in standalone operation is a challenging task A modern-control-based-tracking of power from wind for its best utilization is proposed in this paper for standalone PMSG based hybrid-WECS comprising Battery Energy Storage System (BESS). An Adaptive Synchronous Reference Frame Phase-Locked-Loop (SRF-PLL) based control scheme for load side bi-directional voltage source converter (VSC) is presented for the system. MATLAB/Simulink model is developed for simulation study for the proposed system and the effectiveness of the controller for bi-directional-converter is discussed under different operating conditions: like variable wind-velocity, sudden load variation, and load unbalancing. Converter control scheme enhances the power smoothening, supply-load power-matching. Also it is able to regulate the active & reactive power from PMSG-BESS hybrid system with control of fluctuations in voltage & frequency with respect to varying operating conditions. Proposed controller successfully offers reactive-power-compensation, harmonics-reduction, and power-balancing. The proposed scheme is based on proportional & integral (PI) controller. Also system is experimentally validated in the laboratory-environment and results are presented here.

Download Full-text

A DQ Synchronous Reference Frame Current Control for Grid Connected Photovoltaic Systems usingSingle Phase Cascaded H Bridge Multilevel Inverter

International Journal of Recent Technology and Engineering - 2 ◽

10.35940/ijeat.b3174.129219 ◽

2019 ◽

Vol 8 (4) ◽

pp. 2814-2822

Keyword(s):

Reference Frame ◽

High Performance ◽

Single Phase ◽

Reactive Power ◽

Current Control ◽

Photovoltaic System ◽

Real Component ◽

Phase Inverter ◽

Synchronous Reference Frame ◽

Single Phase Inverter

This paper projects a high performance decoupled current control using a dq synchronous reference frame for single-phase inverter. For the three-phase inverter the conversion from AC to DC with Proportional Integral controller grants to obtain steady state error for AC Voltages and currents but has a few challenges with the single-phase systems. Hence, an orthogonal pair (β) is created by shifting the phase by one quarter cycle with respect to the real component (α) which is needed for the transformation from stationary to rotating frame. The synchronous reference frame control theory helps in controlling the AC voltage by using DC signal as the reference with the proportional integrator controllers. The implementation of the control is done with two-stage converter with LCL filter for a single-phase photovoltaic system. A modified MPPT Incremental conductance algorithm along with decoupled current control helps in regulating the active and reactive power infused into the grid where the power factor is improved, the efficiency of the system is increased above 95% and total harmonic distortion for current is also reduced to3%. The results have been validated using MATLAB.

Download Full-text

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

IJITEE (International Journal of Information Technology and Electrical Engineering) ◽

10.22146/ijitee.28364 ◽

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.

Download Full-text

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

Energies ◽

10.3390/en12244796 ◽

2019 ◽

Vol 12 (24) ◽

pp. 4796 ◽

Cited By ~ 2

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.

Download Full-text

Power Quality Enhancement in Grid Connected PV Systems using High Step Up DC-DC Converter

International Journal of Electrical and Computer Engineering (IJECE) ◽

10.11591/ijece.v7i2.pp720-728 ◽

2017 ◽

Vol 7 (2) ◽

pp. 720

Author(s):

V S Prasadarao K ◽

K V Krishna Rao ◽

P Bala Koteswara Rao ◽

T. Abishai

Keyword(s):

Power Quality ◽

Fossil Fuels ◽

Reactive Power ◽

Neutral Current ◽

Renewable Energy Sources ◽

Current Control ◽

Control Technique ◽

Pv System ◽

Hysteresis Current Control ◽

Switching Losses

Renewable energy sources (RES) are gaining more importance in the present scenario due to the depletion of fossil fuels and increasing power demand. Solar energy is the one of the most promising as it is clean and easily available source. The voltage obtained from the PV system is low. This voltage is increased by high step up dc-dc converter which uses only one switch leads to low switching losses and hence the efficiency of this converter is high. To get the good response this converter is operated in closed loop manner. Integration of PV system with existing grid has so many issues like distorted voltage, current and reactive power control etc. This paper presents a four leg inverter which works on hysteresis current control technique to address the power quality issues like reactive power compensation, balanced load currents and compensation of neutral current. The switching to the inverter is designed in such a way that it supplies the extra current to stabilise the current of the grid that is being supplied to the loads. Finally, the proposed technique is validated by using mat lab/Simulink software and corresponding results are presented in this paper.

Download Full-text

Solar PV fed non-isolated DC-DC converter for BLDC motor drive with speed control

Indonesian Journal of Electrical Engineering and Computer Science ◽

10.11591/ijeecs.v13.i1.pp313-323 ◽

2019 ◽

Vol 13 (1) ◽

pp. 313

Author(s):

G. G RajaSekhar ◽

Basavaraja Banakar

Keyword(s):

Control Method ◽

Speed Control ◽

Current Control ◽

Operating Conditions ◽

Switching Frequency ◽

Bldc Motor ◽

Solar Pv ◽

Pv System ◽

High Switching Frequency ◽

Interleaved Boost Converter

Brushless DC motors (BLDC) are predominantly used these days due to its meritorious advantages over conventional motors. The paper presents PV fed BLDC speeds control system. A closed-loop interleaved boost converter increases the voltage from PV system to required level. Converter for BLDC operates at fundamental switching frequency which reduces losses due to high switching frequency. Internal current control method is developed and employed for the speed control of PV fed BLDC motor by sensing the actual speed feedback. Internal current controlled PV fed BLDC drive is analyzed with increamental speed with fixed torque and decreamental speed with fixed torque operating conditions. Also the system with speed control is verified for variable torque condition. The system is developed and results are developed using MATLAB/SIMULINK software.

Download Full-text

Design of Super Twisting Sliding Mode Controller for a Three-Phase Grid-connected Photovoltaic System under Normal and Abnormal Conditions

Energies ◽

10.3390/en13153773 ◽

2020 ◽

Vol 13 (15) ◽

pp. 3773

Author(s):

Kamran Zeb ◽

Tiago Davi Curi Busarello ◽

Saif Ul Islam ◽

Waqar Uddin ◽

Kummara Venkata Guru Raghavendra ◽

...

Keyword(s):

Steady State ◽

Dynamic Behavior ◽

Reactive Power ◽

Sliding Mode ◽

Operating Conditions ◽

Photovoltaic System ◽

Frequency Variation ◽

Sliding Mode Controller ◽

Pv System ◽

Three Phase

The novelty behind the research in this paper is to investigate the Super Twisting Sliding Mode Controller (ST-SMC) for efficiently injecting both active and reactive power under normal and abnormal operating conditions for a three-phase grid-connected photovoltaic (PV) system. The ST-SMC is aimed to inject sinusoidal current to the grid with low Total Harmonic Distortion (THD), to avoid chattering with easy real implementation, and to enhance the quality of disturbance rejection and sensitivity to parameter variation. The test under normal conditions includes initialization, steady state behavior, dynamic behavior, and interrupting the injection of acting and reactive power while the abnormal conditions consists of voltage sag, voltage swell, frequency variation, DC-link variation, and inclusion of 5th harmonics, etc. The phase lock loop used for synchronization is based on a synchronous reference frame that works well under distorted grids and nonideal. Automatic code is generated in PSIM 9.1 for hardware implementation in the DSP board TMS32F28335 from Texas Instruments while code composer studio 6.2.0 is used for debugging. The real time testing is executed using Typhoon Hardware in Loop (HIL) 402 device on the DSP board. The results authenticate the fastness, effectiveness, and robustness for both steady state and dynamic behavior under various scenarios of the designed controller.

Download Full-text

Nonlinear Robust Backstepping Control for Three-Phase Grid-Connected PV Systems

Mathematical Problems in Engineering ◽

10.1155/2018/3824628 ◽

2018 ◽

Vol 2018 ◽

pp. 1-13 ◽

Cited By ~ 2

Author(s):

Mohamed Habib Boujmil ◽

Afef Badis ◽

Mohamed Nejib Mansouri

Keyword(s):

Control Strategy ◽

Control Structure ◽

Control Process ◽

Backstepping Control ◽

Operating Conditions ◽

Cascade Control ◽

Control Technique ◽

Pv System ◽

Pv Systems ◽

Three Phase

This paper proposes a cascade control structure for three-phase grid-connected Photovoltaic (PV) systems. The PV system consists of a PV Generator, DC/DC converter, a DC link, a DC/AC fully controlled inverter, and the main grid. For the control process, a new control strategy using nonlinear Backstepping technique is developed. This strategy comprises three targets, namely, DC/DC converter control; tight control of the DC link voltage; and delivering the desired output power to the active grid with unity power factor (PF). Moreover, the control process relies mainly on the formulation of stability based on Lyapunov functions. Maximizing the energy reproduced from a solar power generation system is investigated as well by using the Perturb and Observe (P&O) algorithm. The Energetic Macroscopic Representation (EMR) and its reverse Maximum Control Structure (MCS) are used to provide, respectively, an instantaneous average model and a cascade control structure. The robust proposed control strategy adapts well to the cascade control technique. Simulations have been conducted using Matlab/Simulink software in order to illustrate the validity and robustness of the proposed technique under different operating conditions, namely, abrupt changing weather condition, sudden parametric variations, and voltage dips, and when facing measurement uncertainties. The problem of controlling the grid-connected PV system is addressed and dealt by using the nonlinear Backstepping control.

Download Full-text

Reactive Power Compensation with PV Inverters for System Loss Reduction

Energies ◽

10.3390/en12214062 ◽

2019 ◽

Vol 12 (21) ◽

pp. 4062 ◽

Cited By ~ 3

Author(s):

Vlahinić ◽

Franković ◽

Komen ◽

Antonić

Keyword(s):

Distribution System ◽

Reactive Power ◽

Voltage Regulation ◽

Active Power ◽

Operating Conditions ◽

Positive Energy ◽

Loss Reduction ◽

Pv System ◽

Pv Penetration ◽

Power Provisioning

Photovoltaic (PV) system inverters usually operate at unitary power factor, injecting only active power into the system. Recently, many studies have been done analyzing potential benefits of reactive power provisioning, such as voltage regulation, congestion mitigation and loss reduction. This article analyzes possibilities for loss reduction in a typical medium voltage distribution system. Losses in the system are compared to the losses in the PV inverters. Different load conditions and PV penetration levels are considered and for each scenario various active power generation by PV inverters are taken into account, together with allowable levels of reactive power provisioning. As far as loss reduction is considered, there is very small number of PV inverters operating conditions for which positive energy balance exists. For low and medium load levels, there is no practical possibility for loss reduction. For high loading levels and higher PV penetration specific reactive savings, due to reactive power provisioning, increase and become bigger than additional losses in PV inverters, but for a very limited range of power factors.

Download Full-text

A Mathematical Model and Performance Evaluation for a Single-Stage Grid-Connected Photovoltaic (PV) System

International Journal of Emerging Electric Power Systems ◽

10.2202/1553-779x.2033 ◽

2008 ◽

Vol 9 (6) ◽

Cited By ~ 7

Author(s):

Prajna Paramita Dash ◽

Amirnaser Yazdani

Keyword(s):

Mathematical Model ◽

Control Strategy ◽

Voltage Control ◽

Current Control ◽

Operating Conditions ◽

Single Stage ◽

Control Loop ◽

Pv System ◽

Wide Range ◽

The Impact

This paper proposes a control strategy for important transients of a single-stage, three-phase, PV system that is connected to a distribution network. The proposed control strategy adopts an inner current-control loop and an outer DC-link voltage control loop. The current-control mechanism renders the PV system protected against external faults, enables control of the DC-link voltage and, therefore, controls/maximizes the PV system power output. The paper also proposes a feed-forward compensation strategy for the DC-link voltage control loop to mitigate the impact of the nonlinear characteristic of the PV array on the closed-loop stability, and to permit design and optimization of the DC-link voltage controller for a wide range of operating conditions. A mathematical model and a control design methodology are presented for the PV system, and it is shown that under the proposed control, the PV system fulfills the operational requirements of a grid-connected PV system. The effectiveness of the proposed control strategy and the most important transients of the PV system are evaluated through simulation studies conducted on a detailed switched model of the PV system in the PSCAD/EMTDC software environment.

Download Full-text