scholarly journals Voltage Quality Enhancement of Grid-Integrated PV System Using Battery-Based Dynamic Voltage Restorer

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5742
Author(s):  
Emiyamrew Minaye Molla ◽  
Cheng-Chien Kuo

The advancement of power electronic-based sensitive loads drives the power utilities’ devotion to power quality issues. The voltage disturbance could be happening due to fault conditions, switching of loads, energizing of transformers, or integration of highly intermittent energy sources such as PV systems. This research work attempts to enhance the voltage fluctuation of a sensitive load connected to a grid-integrated PV system using a battery-based dynamic voltage restorer (DVR). The proposed battery energy storage-based DVR has two separate controlling stages that are implemented at the DC–DC buck/boost converter of the battery and voltage source converter (VSC) system. Charging and discharging of the battery is operated based on the state-of-charge (SOC) value of the battery and the measured root mean square (RMS) voltage at the point of common coupling (PCC). The VSC of the DVR detection and reference generation control is done appropriately. In the detection control of the VSC, a combination of RMS and dq0 measurement techniques is used, whereas in the reference generation control, pre-fault strategy is implemented to restore both phase jump and magnitude distortions. Symmetrical and asymmetrical voltage sags scenarios are considered and the compensation demonstration is carried out using power system computer-aided design (PSCAD/EMTDC) software.

Author(s):  
Syed Suraya ◽  
P. Sujatha ◽  
P. Bharat Kumar

This paper presents a novel control strategy to control DG integrated DVR (dynamic voltage restorer) for mitigation voltage quality problems. Power quality is the most concerning areas in power engineering and voltage quality is of prime focus. Voltage sag, voltage swell and harmonics in voltage causes deterioration in quality of voltage delivered to load. A minor disturbance in voltage profile can degrade the performance of load. Dynamic voltage restorer is a quick responsive custom power device for voltage quality improvement. Photovoltaic (PV) system is considered as DG and output voltage of PV system is boosted with a boost converter to support voltage source converter of DVR. DG integrated DVR with novel control strategy for mitigation of voltage sag, swell and voltage harmonic is presented in this paper. The power system model with DG integrated DVR is developed and results are obtained using MATLAB/SIMULINK. Results are discussed during pre and post sag/swell condition with compensation and THD in voltage is maintained within nominal values.


Author(s):  
Syed Suraya ◽  
P. Sujatha P ◽  
Bharat Kumar. P

Power quality is one of the areas that the power sector is worried about. Power quality is the measure of practical system resemblance to ideal system. Voltage quality can be defined as the maintenance of voltage waveform shape close to ideal shape with proper magnitude and frequency. Even a slight change in voltage of the system can cause serious damage to the power system. Sensitive loads cannot adjust for small change in voltage. This paper presents Dynamic Voltage Restorer (DVR) for voltage harmonic suppression along with sag/swell compensation in distribution system. DVR is a voltage source converter which sends compensating signals when operated through switches of voltage source converter. This paper presents a novel control strategy to control DVR to block out the voltage harmonics in distribution system. The models and results are developed using MATLAB/SIMULINK software and comparative analysis of source voltage harmonics and load voltage harmonics during sag/swell compensation was tabulated.


2018 ◽  
Vol 7 (3) ◽  
pp. 1351
Author(s):  
Rakeshwri Pal ◽  
Sushma Gupta

Among various power quality problems, voltage sag and swell are dominant where loads are very sensitive to the voltage disturbances. Various custom power devices are introduced recently to overcome these voltage issues, dynamic voltage restorer (DVR) is one of them. It offers very cost effective solution for problems such as voltage sag, swell and harmonics by establishing the proper voltage level during voltage disturbances to protect sensitive loads. In this paper, performance of DVR to improve power quality is done for solar photovoltaic (PV) based generation system feeding the grid and the three phase linear load. Solar PV generation system is implemented with an incre-mental conductance (IC) maximum power point tracking (MPPT) technique.  The DVR is connected in between solar PV system and load. The basic structure of DVR is modified by using the photovoltaic system as an alternative to DC source and in place of conventional 2-level voltage source converter (VSC) neutral point clamped (NPC) multi level inverter is used. The system performance is analyzed in the MATLAB/Simulink environment. The simulation results justified the efficiency of modified DVR in the mitigation of voltage sag in distri-bution system. Improvement of power quality by stabilizing voltage during fault and promoting renewable energy is the main framework of this work.  


Author(s):  
Abdelkrim Benali ◽  
Mounir Khiat ◽  
Mouloud Denai

<p class="Abstract">In this paper, we have presented a simulation study to analyze the power quality of three phases medium voltage grid connected with distribution generation (DG) such as photovoltaic (PV) farms and its control schemes. The system uses two-stage energy conversion topology composed of a DC to DC boost converter for the extraction of maximum power available from the solar PV system based on incremental inductance technique and a three-level voltage source inverter (VSI) to connect PV farm to the power grid. To maintain the grid voltage and frequency within tolerance following disturbances such as voltage swells and sags, a fuzzy logic-based Dynamic Voltage Restorer is proposed. The role of the DVR is to protect critical loads from disturbances coming from the network. Different fault conditions scenarios are tested and the results such as voltage stability, real and reactive powers, current and power factor at the point of common coupling (PCC) are compared with and without the DVR system.</p>


Author(s):  
Jamal Abdul-Kareem Mohammed ◽  
Arkan Ahmed Hussein ◽  
Sahar R. Al-Sakini

<p>Power distribution network in Iraq still suffers from significant problems regarding electricity distribution level. The most important problem is the disturbances that are occurring on lines voltages, which in turn, will negatively affect sensitive loads they feed on. Protection of these loads could be achieved efficiently and economically using the dynamic voltage restorer DVR when installed between the voltage source and load to inject required compensation voltage to the network during the disturbances period. The DVR mitigates these disturbances via restoring the load voltage to a pre-fault value within a few milliseconds. To control the DVR work, dq0 transformation concept and PID method with sinusoidal pulse-width modulation SPWM based converter had been used to correct the disturbances and thus enhance the power quality of the distribution network. The DVR performance was tested by MATLAB/Simulink with all kinds of expected voltage disturbances and results investigated the effectiveness of the proposed method.</p>


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