Control Scheme of Energy Storage Power Converter for Active and Reactive Power Balancing in Grid Connected PV Micro-Grids
Issue:
Volume 5, Issue 4, July 2016
Pages:
28-34
Received:
5 September 2016
Accepted:
14 September 2016
Published:
28 September 2016
Abstract: Micro-Grid (MG) is a small-scale power network associated with Renewable Energy Sources (RES), Energy Storage System (ESS) and local critical loads. MGs can either be connected to the main grid or operate stand-alone. Due to variable nature of RES such as Photovoltaic (PV) solar cells, ESS become necessary to maintain reliability of power supply to critical loads during islanded mode. During grid connected mode, ESS is used to support the grid or MG depending on the grid operator and energy management functions. On the other hand, the power converters interfaced ESS can be used to provide additional services to the main grid, such as reactive power and unbalanced compensation. This paper presents a control strategy for an Energy Storage Power Converter (ESPC) in MGs, in order to mitigate the negative effects of grid connected MGs working with highly unbalanced operation and poor power factor conditions. Simulation results have been carried out by using Matlab – Simulink software to verify the effectiveness of the proposed control scheme.
Abstract: Micro-Grid (MG) is a small-scale power network associated with Renewable Energy Sources (RES), Energy Storage System (ESS) and local critical loads. MGs can either be connected to the main grid or operate stand-alone. Due to variable nature of RES such as Photovoltaic (PV) solar cells, ESS become necessary to maintain reliability of power supply to...
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Fault Analysis of Grid Connected Photovoltaic System
Prakash Kumar Hota,
Babita Panda,
Bhagabat Panda
Issue:
Volume 5, Issue 4, July 2016
Pages:
35-44
Received:
16 August 2016
Accepted:
3 September 2016
Published:
29 September 2016
Abstract: A new method of current control strategy for grid connected photovoltaic (PV) system is presented in this paper. The connection of photovoltaic system with the grid is a difficult task as the solar irradiation is a nonlinear quantity. The objective of this work is to develop a model of the photovoltaic system with maximum power point tracking (MPPT) system connected to 11 KV grid by implementing new control technique so that maximum active power transfer from PV to grid can be taken place without injection of harmonics. The considered system consists of a PV system, MPPT controller, boost converter, voltage source inverter (VSI), 3-Φ filter, a control system, a distribution network, load and grid. In the beginning, a model of a photovoltaic array was developed and then a MPPT controller and a direct current to direct current (DC-DC) converter are designed. To connect PV system to grid, a power electronics converter is needed which can convert DC voltage into three- phase AC voltage. Three-phase VSI using insulated gate bipolar transistors (IGBTs) is used. By means of a step-up transformer and filter, this three-phase VSI is connected to the distribution network. The proposed control of the three-phase grid-connected solar PV system is designed in the synchronously-rotating d-q reference frame. Here, Vdc is measured, then compared with Vdcref and accordingly the error is fed to proportional-integral (PI) controller from which Idref is generated. As PV system should inject only active power, so reactive power injected to grid is made zero by making Iqref zero. There after the final model is simulated by using MATLAB/SIMULINK and different output waveforms are analyzed for different conditions. Finally the fault analysis is carried out to observe the behavior of the system.
Abstract: A new method of current control strategy for grid connected photovoltaic (PV) system is presented in this paper. The connection of photovoltaic system with the grid is a difficult task as the solar irradiation is a nonlinear quantity. The objective of this work is to develop a model of the photovoltaic system with maximum power point tracking (MPPT...
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