scholarly journals Compensation of voltage Sag using STATCOM

2018 ◽  
Vol 7 (2.8) ◽  
pp. 673
Author(s):  
Savitha Venkatesan ◽  
Booma Nagarajan

Due to unpredicted non-linear loads, power quality problems, a raise in the transmission system. One such problem is voltage sag. Voltage sag is caused by the non-linear load which demands reactive power, but the balanced 3F source provides required reactive power of the load with reduced voltage at the receiving end. In this paper, simulation study has been performed to reducethe voltage sag issue. A transmission system with generation source with different loading conditions is considered and study has been done. A 3F medium P model transmission line is designed with a power source of 11kV.  A shunt connected compensation unit called Static Synchronous Compensator (STATCOM) reduces the voltage sag in the transmission line. STATCOM provides the required reactive power demanded by the non-linear load along with the source for compensation of voltage sag. The STATCOM circuit comprises of Voltage source converter(VSC) unit and a DC source. Reactive power compensation is done by VSC unit firing angle control. The source of the STATCOM can also be from renewable energy system. This AC source is converted by a AC-DC-AC converter unit.The firing angle is controlled by the control unit which ensures the continuous and balanced power flow even under sudden change in load conditions. The simulation results depict the characteristics of the developed STATCOM.

Author(s):  
Akram Qashou ◽  
Sufian Yousef ◽  
Abdallah A. Smadi ◽  
Amani A. AlOmari

AbstractThe purpose of this paper is to describe the design of a Hybrid Series Active Power Filter (HSeAPF) system to improve the quality of power on three-phase power distribution grids. The system controls are comprise of Pulse Width Modulation (PWM) based on the Synchronous Reference Frame (SRF) theory, and supported by Phase Locked Loop (PLL) for generating the switching pulses to control a Voltage Source Converter (VSC). The DC link voltage is controlled by Non-Linear Sliding Mode Control (SMC) for faster response and to ensure that it is maintained at a constant value. When this voltage is compared with Proportional Integral (PI), then the improvements made can be shown. The function of HSeAPF control is to eliminate voltage fluctuations, voltage swell/sag, and prevent voltage/current harmonics are produced by both non-linear loads and small inverters connected to the distribution network. A digital Phase Locked Loop that generates frequencies and an oscillating phase-locked output signal controls the voltage. The results from the simulation indicate that the HSeAPF can effectively suppress the dynamic and harmonic reactive power compensation system. Also, the distribution network has a low Total Harmonic Distortion (< 5%), demonstrating that the designed system is efficient, which is an essential requirement when it comes to the IEEE-519 and IEC 61,000–3-6 standards.


Author(s):  
Satyanarayan Gorantla ◽  
Goli Ravi Kumar

The paper presents the analysis of harmonic distortion when non-linear load is connected in different phases of power system with STATCOM for singly excited induction generator system with wind turbine as prime mover. Now-a-days due to the drastically increased in use of non linear loads causes many power quality problems in power system network. Those problems are classified as reactive power problems, harmonics, voltage sags and swells. Out of these problems harmonic problems are major concern. Custom power devices proposed for mitigation of power quality in network. For compensation of harmonic, static compensator (STATCOM) is used. The paper presents the compensation of harmonic power quality issues using STATCOM for the system with singly-excited induction generator feeding non-linear load connected in different phases. STATCOM is controlled using synchronous reference frame theory to produce pulses to switches of STATCOM sensing the input parameters. Proposed concept was developed using MATLAB/SIMULINK software and results are presented for non-linear load connected in different phases of the power system. THD analysis was shown for source current and load current for different cases.


2014 ◽  
Vol 626 ◽  
pp. 184-189
Author(s):  
A.S. Monikandan ◽  
N. Kesavan Nair

The Interline Power Flow Controller (IPFC) is a voltage-source-converter (VSC)-based flexible ac transmission system (FACTS) controller for series compensation in a multiline transmission system of a substation. The capability of injecting series voltages with controllable magnitude and phase angle makes it a powerful tool for better utilization of existing transmission lines in a multiline transmission system. IPFC is used to regulate active and reactive power flow in a multiline system, usually. In this paper, a control method for IPFC is proposed to control magnitude and phase angle of one sending bus of a substation. All degrees of freedom of IPFC and decoupled synchronous frame concept are used in the proposed control structure. Simulation results in Matlab/Simulink are presented to show the capability of IPFC in compensating the bus voltage.


Author(s):  
Ameerul A. J. Jeman ◽  
Naeem M. S. Hannoon ◽  
Nabil Hidayat ◽  
Mohamed.M.H. Adam ◽  
Ismail Musirin ◽  
...  

<span>Voltage-source converter (VSC) topology is widely used for grid interfacing of distributed generation (DG) systems such as the photovoltaic system (PV). Since the operation of the VSC is essential to ensure quality of active and reactive power injected to the grid, a control approach is needed to deal with the uncertainties in the grid such as faults. This paper presents a non-linear controller design for a three-phase voltage source converter (VSC). The dynamic variables adopted for the VSC are the instantaneous real and reactive power components. The control approach that interface the VSC between the PV system and the grid are subjected to the current-voltage based. PV system injects active power to the grid and local load while utility grid monitors the power compensation of load reactive power. The proposed non-linear control strategy is implemented for the VSC to ensure fast error tracking and finite convergence time. The adaptive nature of the proposed non-linear control provides more robustness, less sluggish fault recovery compared to conventional PI control. The comprehensive numerical model is demonstrated in MATLAB script environment with power system disturbances such as faults in the grid. The simulation of proposed system is being carried out in MATLAB/SIMULINK environment to validate the control scheme. The proposed control system regulates the VSC ac side real and reactive power component and the dc side voltage.</span>


2018 ◽  
Vol 7 (1.8) ◽  
pp. 210
Author(s):  
M Naga Chaitanya ◽  
D Rajesh ◽  
K Sujith ◽  
R Santhoshi ◽  
B Phanendra

This paper proposes a concept of Fuzzy based Active Power Filter for mitigating current harmonics in interconnected PV-Grid system. The PV array is connected to the utility grid by using a boost converter and a voltage source converter. For this, a three phase three wire system operated by non-linear load is considered. The increased harmonic content leads to increase in losses, decrease in power factor and many adverse effects. A Fuzzy based instantaneous PQ theory control technique is proposed in this paper for better harmonic compensation. This proposed system is tested and verified using Matlab/Simulink. The results obtained in both PI and fuzzy based APF systems are compared in the aspects of THD and active power. 


Author(s):  
Amirullah Amirullah ◽  
Ontoseno Penangsang ◽  
Adi Soeprijanto

This paper presents performance analysis of Unified Power Quality Conditioner-Battery Energy Storage (UPQC-BES) system supplied by Photovoltaic (PV)-Wind Hybrid connected to three phase three wire (3P3W) of 380 volt (L-L) and 50 hertz distribution system. The performance of supply system is compared with two renewable energy (RE) sources i.e. PV and Wind, respectively. Fuzzy Logic Controller (FLC) is implemented to maintain DC voltage across the capacitor under disturbance scenarios of source and load as well as to compare the results with Proportional Intergral (PI) controller. There are six scenarios of disturbance i.e. (1) non-linear load (NL), (2) unbalance and nonlinear load (Unba-NL), (3) distortion supply and non-linear load (Dis-NL), (4) sag and non-linear load (Sag-NL), (5) swell and non-linear load (Swell-NL), and (6) interruption and non-linear load (Inter-NL). In disturbance scenario 1 to 5, implementation of FLC on UPQC-BES system supplied by three RE sources is able to obtain average THD of load voltage/source current slightly better than PI. Furthermore under scenario 6, FLC applied on UPQC-BES system supplied by three RE sources gives significantly better result of average THD of load voltage/source current than PI. This research is simulated using Matlab/Simulink.


2015 ◽  
Vol 17 (4) ◽  
Author(s):  
Arkhan Subari ◽  
Saiful Manan

Arkhan Subari, Saiful Manan, in this paper explain that most electronic equipment is non-linear load. Likewise with the equipment in campus buildings Diploma III Faculty of Engineering. Non-linear load is a load that has a voltage waveform supplied from non sinusiodal although sinusoidal voltage. Non-sinusoidal wave causes the shape of the voltage becomes distorted or defects that result in decreased quality of power. The defect wave called harmonics. To dampen harmonics on non-linear load can be used filter. With the addition of a filter on the power system, then the waves of unwanted harmonics can be suppressed as small as possible. In addition, harmonic filter at the fundamental frequency can compensate for reactive power and is used to improve the power factor of the system. From the measurement results in the Diploma Program Campus FT Undip found that the influence of harmonic waves big enough. THDv reached 32.13% while the THDi amounted to 7.85%. It affects so cos phi cos phi measured just 0.72. After the installation of a passive filter, the value THDv and THDi be good lebik ie 1.61% and 0.39% to reach 0.94 cos phi measured. Key word: non-linear loads, non-sinusoidal waveform, harmonics, power factor, filter LC


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