Grid-Connected Control Strategy Based on Fixed Mi Coefficient for Single-Phase Photovoltaic System

2014 ◽  
Vol 494-495 ◽  
pp. 1764-1770
Author(s):  
Wen Jie Zhu ◽  
Fei Rong ◽  
An Luo ◽  
Yong Xu ◽  
An Ping Hu
Keyword(s):  
Control Strategy ◽  
Single Phase ◽  
Closed Loop ◽  
Harmonic Distortion ◽  
Photovoltaic System ◽  
Voltage Source ◽  
Harmonic Suppression ◽  
Pv System ◽  
Simulation And Experiment ◽  
The Stability

This paper presents a grid-connected control strategy for single-phase photovoltaic (PV) system. Voltage source inverter (VSI) of a PV system is a core component which will produce some harmonics when the switch is operated between on and off continuously. To suppress harmonic distortion in the VSI output current, a fixed modulation index (MI) control loop based on PI controller is added to the traditional double closed-loop. The proposed method can fix the MI coefficient to be a large value in any conditions. The design of the controller and the stability of the grid-connected system are discussed in detail. Simulation and experiment results are presented to demonstrate the dynamic and precision performance of the controller for harmonic suppression when the proposed PV system is connected to the grid.

scholarly journals A Control Strategy of a Single-phase H6-type Grid-connected Inverter with Low Harmonic Current

2018 ◽  
Vol 173 ◽  
pp. 02041
Author(s):  
Lin Chunxu ◽  
Zhou Chunhua ◽  
Li Wei ◽  
Chen Rui
Keyword(s):  
Control Strategy ◽  
Single Phase ◽  
Closed Loop ◽  
High Efficiency ◽  
Control Method ◽  
Harmonic Distortion ◽  
Outer Loop ◽  
Lcl Filter ◽  
Loop Control ◽  
Grid Connected Inverter

In order to reduce the total harmonic distortion (THD) of the grid-connected current caused by the high-frequency switching of the inverter, this paper combines the high efficiency single-phase H6-type inverter with LCL filter. The double closed-loop control method that consists of grid-connected current outer loop and capacitor current inner loop is put forward, by which a resonance peak of a low damping LCL filter is eliminated. In the grid-connected current outer loop, quasi proportion resonant (QPR) controller is adopted to overcome the steady-state error and weak anti-jamming capability in traditional PI controller. Finally, a simulation model is built in SIMULINK to verify the research. The simulation results show that, based on the single-phase H6-type inverter and LCL filter, the double closed-loop QPR control strategy can achieve the static error free tracking control of grid-connected current, which makes the system more stable and reduces the THD of grid-connected current effectively.

scholarly journals Efficient Control of a Three Phase Grid Connected PV System

2021 ◽  
Vol 297 ◽  
pp. 01012
Author(s):  
Hicham Bahri ◽  
Mohamed Bahri ◽  
Mohamed Aboulfatah ◽  
M’hammed Guisser ◽  
El malah Mohammed ◽  
...  
Keyword(s):  
Control Strategy ◽  
High Efficiency ◽  
Control Strategies ◽  
Dynamic Performance ◽  
Atmospheric Condition ◽  
Photovoltaic System ◽  
Voltage Source ◽  
Good Precision ◽  
Pv System ◽  
Three Phase

This paper presents a new control strategy of a photovoltaic system, which consists of a photovoltaic generator PVG coupled to a three phase load and three phase grid by a three phase voltage source inverter VSI without DC-DC converter. The controller is designed by using Backstepping method based on d-q transformation of a new model of the global system. The main goals of this control strategy are to achieve the maximum power point MPPT with very good precision and the unity power factor in level of the grid power flow. Mathematical analysis demonstrate the asymptotic stability of the controlled system and simulation results proved that the controller has achieved all the objectives with high dynamic performance in presence of atmospheric condition changes. Moreover, the proposed controller shows a very good robustness under system disturbance, which presents the most important advantage of this controller compared to the other control strategies. Furthermore, this controller can operate with a high efficiency with any kind of the load.

scholarly journals Control of Power and Voltage of Solar Grid Connected

2016 ◽  
Vol 6 (1) ◽  
pp. 26 ◽  
Author(s):  
Boucetta Abd Allah ◽  
Labed Djamel
Keyword(s):  
Control Strategy ◽  
High Efficiency ◽  
Harmonic Distortion ◽  
Maximum Power ◽  
Photovoltaic System ◽  
Pv System ◽  
Maximum Power Point ◽  
Three Phase ◽  
Power Point ◽  
Computational Resources

Renewable energy is high on international agendas. Currently, grid-connected photovoltaic systems are a popular technology to convert solar energy into electricity. Control of power injected into the grid, maximum power point, high efficiency, and low total harmonic distortion of the currents injected into the grid are the requirements for inverter connection into the grid. Consequently, the performance of the inverters connected to the grid depends largely on the control strategy applied. In this paper the simulation and design of grid connected three phase photovoltaic system using Matlab/Simulink has examined. The proposed system consists photovoltaic panels, boost and inverter the PV system convert the sun irradiation into direct current, thereafter we have used a boost to track the maximum power point of the PV system, three-phase inverter and LC output filter. A VOC control strategy based on the phase shifting of the inverter output voltage with respect to the grid voltage. The proposed control strategy requires few hardware and computational resources. As a result, the inverter implementation is simple, and it becomes an attractive solution for low power grid connected applications.

scholarly journals Control of power and voltage of solar grid connected

2016 ◽  
Vol 6 (1) ◽  
pp. 26 ◽  
Author(s):  
Boucetta Abdou Abdallah ◽  
Labed Djamel
Keyword(s):  
Control Strategy ◽  
High Efficiency ◽  
Harmonic Distortion ◽  
Maximum Power ◽  
Photovoltaic System ◽  
Pv System ◽  
Maximum Power Point ◽  
Three Phase ◽  
Power Point ◽  
Computational Resources

Renewable energy is high on international agendas. Currently, grid-connected photovoltaic systems are a popular technology to convert solar energy into electricity. Control of power injected into the grid, maximum power point, high efficiency, and low total harmonic distortion of the currents injected into the grid are the requirements for inverter connection into the grid. Consequently, the performance of the inverters connected to the grid depends largely on the control strategy applied. In this paper the simulation and design of grid connected three phase photovoltaic system using Matlab/Simulink has examined. The proposed system consists photovoltaic panels, boost and inverter the PV system convert the sun irradiation into direct current, thereafter we have used a boost to track the maximum power point of the PV system, three-phase inverter and LC output filter. A VOC control strategy based on the phase shifting of the inverter output voltage with respect to the grid voltage. The proposed control strategy requires few hardware and computational resources. As a result, the inverter implementation is simple, and it becomes an attractive solution for low power grid connected applications.

scholarly journals Dual Two-Level Voltage Source Inverter Virtual Inertia Emulation: A Comparative Study

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1160
Author(s):  
Mohammad Ali Dashtaki ◽  
Hamed Nafisi ◽  
Amir Khorsandi ◽  
Mojgan Hojabri ◽  
Edris Pouresmaeil
Keyword(s):  
Harmonic Distortion ◽  
Synchronous Generator ◽  
Voltage Source ◽  
Small Signal ◽  
Voltage Source Inverter ◽  
Nonlinear Loads ◽  
Virtual Inertia ◽  
The Stability ◽  
Stability Enhancement ◽  
Oscillation Damping

In this paper, the virtual synchronous generator (VSG) concept is utilized in the controller of the grid-connected dual two-level voltage source inverter (DTL VSI). First, the topology of the VSG and the DTL VSI are presented. Then, the state-space equations of the DTL VSI and the grid-connected two-level voltage source inverter (TL VSI), regarding the presence of the phase-locked loop (PLL) and the VSG, are given. Next, the small-signal modeling of the DTL VSI and the TL VSI is realized. Eventually, the stability enhancement in the DTL VSI compared with the TL VSI is demonstrated. In the TL VSI, large values of virtual inertia could result in oscillations in the power system. However, the ability of the DTL VSI in damping oscillations is deduced. Furthermore, in the presence of nonlinear loads, the potentiality of the DTL VSI in reducing grid current Total Harmonic Distortion (THD) is evaluated. Finally, by using a proper reference current command signal, the abilities of the DTL VSI and the TL VSI in supplying nonlinear loads and providing virtual inertia are assessed simultaneously. The simulation results prove the advantages of the DTL VSI compared with the TL VSI in virtual inertia emulation and oscillation damping, which are realized by small-signal analysis.

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 A Grid-Supporting Photovoltaic System Implemented by a VSG with Energy Storage

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3152 ◽  
Author(s):  
Huadian Xu ◽  
Jianhui Su ◽  
Ning Liu ◽  
Yong Shi
Keyword(s):  
Energy Storage ◽  
Synchronous Generator ◽  
Photovoltaic System ◽  
Voltage Source ◽  
Frequency Regulation ◽  
Pv System ◽  
Storage Unit ◽  
Support Functions ◽  
Energy Storage Unit ◽  
Pv Systems

Conventional photovoltaic (PV) systems interfaced by grid-connected inverters fail to support the grid and participate in frequency regulation. Furthermore, reduced system inertia as a result of the integration of conventional PV systems may lead to an increased frequency deviation of the grid for contingencies. In this paper, a grid-supporting PV system, which can provide inertia and participate in frequency regulation through virtual synchronous generator (VSG) technology and an energy storage unit, is proposed. The function of supporting the grid is implemented in a practical PV system through using the presented control scheme and topology. Compared with the conventional PV system, the grid-supporting PV system, behaving as an inertial voltage source like synchronous generators, has the capability of participating in frequency regulation and providing inertia. Moreover, the proposed PV system can mitigate autonomously the power imbalance between generation and consumption, filter the PV power, and operate without the phase-locked loop after initial synchronization. Performance analysis is conducted and the stability constraint is theoretically formulated. The novel PV system is validated on a modified CIGRE benchmark under different cases, being compared with the conventional PV system. The verifications demonstrate the grid support functions of the proposed PV system.

scholarly journals Fractional Order PID Controlled Cascaded Re-boost Seven Level Inverter Fed Induction Motor System with Enhanced Response

2018 ◽  
Vol 9 (4) ◽  
pp. 1784
Author(s):  
P. Bhaskara Prasad ◽  
M. Padma Lalitha ◽  
B. Sarvesh
Keyword(s):  
Dynamic Response ◽  
Induction Motor ◽  
Motor System ◽  
Single Phase ◽  
Closed Loop ◽  
Photovoltaic System ◽  
Voltage Response ◽  
Voltage Gain ◽  
Boost Regulator ◽  
Fractional Order Pid

<span lang="EN-US">Recently, Re-boost seven-level inverter has been developed as an alternative between Photovoltaic system and single-phase load. DC level is increased using a re-boost regulator and its output is rehabilitated into single-phase AC utilizing a seven-level inverter. The re-boost converter is utilized to escalate the voltage gain. The objective of the suggested closed loop Re-boost Seven Level Inverter fed Induction Motor (RBSLIIM) system is to enhance the dynamic response of RBSLIIM using FO-P-I-D controller. Simulink models are developed for P-I and FO-P-I-D controlled RBSLIIM systems. The results of P-I and FO-P-I-D based RBSLIIM systems indicate that the voltage response with FO-P-I-D is superior to P-I controlled RBSLIIM system.</span>

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.

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