Mitigation of voltage swells in IEEE 30 bus and IEEE 57 bus systems using evolutionary techniques

2018 ◽  
Vol 20 (4) ◽  
pp. 499-516
Author(s):  
Yasser ABOELAZM ◽  
Wael E. WAHBA
Keyword(s):  
Electronics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 612
Author(s):  
Sajad Abdali Nejad ◽  
José Matas ◽  
Helena Martín ◽  
Jordi de la Hoz ◽  
Y. A. Al-Turki

The SOGI-FLL (Second-Order Generalized Integrator–Frequency-Locked Loop) is a well-known and simple adaptive filter that allows for estimating the parameters of grid voltage with a small computational burden. However, the SOGI-FLL has been shown to be especially sensitive to voltage sags and voltage swells, which deeply distort the estimated parameters, especially the frequency. This problem can be alleviated by simply using a saturation block at the Frequency-Locked Loop (FLL) output to limit the impact of distortion on the estimated frequency. Improving upon this straightforward approach, in this paper we propose the use of a finite state machine (FSM) for the definition of the different states of the SOGI-FLL frequency response during a voltage sag or swell fault. The FSM approach allows for applying different gains during the fault, enhancing the SOGI-FLL transient response. The performance of the FSM-based SOGI-FLL is evaluated by using simulation results, which show a better and faster response to these kinds of faults.


2013 ◽  
Vol 8-9 ◽  
pp. 127-138 ◽  
Author(s):  
Anca Miron ◽  
Mircea D. Chindris ◽  
Andreas Sumper

The paper shows how the surveying of power quality in microgrids working under unbalanced harmonic distorted operating states with possible voltage dips and voltage swells existence can be accomplished implying a small amount of time and measurement activities. The surveying methodology uses the disturbances propagation phenomenon to determine the power quality indices in all of interest nodes of the microgrid utilizing the voltages and currents characteristics in one or several strategic nodes. The disturbances propagation is based on the sequence component theory applied for all detected harmonics and for the microgrids components. The proposed surveying methodology was implemented in a virtual instrument capable to acquire the voltages and currents waveforms, to analyze them in order to identify the disturbances characteristics, to calculate the disturbances propagation and display the power quality indices in all of interest nodes of the microgrid. The virtual instrument was tested using several microgrid topologies and scenarios.


Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1541
Author(s):  
Yu-Kai Chen ◽  
Xian-Zhi Qiu ◽  
Yung-Chuna Wu ◽  
Chau-Chung Song

In this paper, the compensation of voltage sags and swells using a dynamic voltage restorer (DVR) based on a bi-directional AC/AC converter is presented for stabilizing single-phase AC line voltage. The H-bridge AC/AC converter with bi-directional switches and without bulk capacitor is adopted as the power topology of the proposed system. The proposed novel topology of DVR is adopted to compensate both voltage sag and swell conditions. Additionally, the power factor is closed to unity because a bulk capacitor is not required. The inner and outer loop control is proposed to improve the response with gain scaling; gain control is adopted to reduce the overshoot. Finally, a 2 kVA prototype has been implemented to verify the performance and accuracy of the control method for the DVR system. The peak efficiency of the system is up to 94%, and it can compensate 50% voltage swells and 25% voltage sags.


The presence of voltage swells over the DC connection of the successful rotor side converter of a Doubly Fed Induction Generator (DFIG) is natural because of vulnerability in twist vitality and in addition the variety of rotor precise speed. This can weaken the execution of the consecutive converter associated on the rotor side of the DFIG. Subsequently, the principle goal of this paper is to plan a criticism linearization procedure to dispose of the dc-interface voltage swell and additionally acquire solidarity control factor. In this paper, the dynamic demonstrating of DFIG alongside the viable rotor side converter is performed. The criticism linearization strategy controls the inward elements of the successful rotor side converter by considering the rotor q-pivot current and DC connect voltage. The MATLAB recreation results portray the viability of the voltage control strategy, through the varieties of rotor side channel, DC interface capacitance and vulnerabilities in the DC connect voltage.


2018 ◽  
Vol 7 (3.29) ◽  
pp. 26
Author(s):  
M Maheswari ◽  
S Thangavel

The quality of the electrical power delivered to consumers is heavily affected by the power electronics based controllers, introduced in both domestic and industrial sectors, which in turn results in malfunctioning of equipment or eventual damage. Series compensators, Shunt compensators and series-shunt compensators are some of the strategies applied to address the power quality issues effectively. In this work a series compensating device, viz. 27 level-cascaded multilevel inverter based Dynamic Voltage Restorer (DVR) with multicarrier SPWM technique is proposed to mitigate voltage swells and voltage sags. The PWM technique used in this work is Alternate Phase Opposition PWM (APODPWM), which is one of the vertical arrangement multicarrier sinusoidal pulse width modulation techniques, to control the cascaded H-bridge inverter. The single-phase version of the proposed system is simulated to verify the effectiveness in addressing voltage issues and it is found that the obtained simulation results are satisfactory. The THD is found to be 3.40%, which is well below IEEE standards apart from considerable improvement in response time. The prototype of the proposed model is developed and the pic-microcontroller PIC16F887 is employed to implement the APODPWM. The experimental results obtained from the prototype are compared with the respective simulation results and they match with reasonable accuracy.  


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