scholarly journals Time-domain harmonic extraction algorithms for three-level inverter-based shunt active power filter under steady-state and dynamic-state conditions-an evaluation study

Author(s):  
Ali Saadon Al-Ogaili ◽  
Agileswari Ramasamy ◽  
Yap Hoon ◽  
Renuga Verayiah ◽  
Marayati Marsadek ◽  
...  

Power quality is a major consideration in all office equipment, manufacturies and residential home appliances. Harmonic distortion is one of the crucial power quality issues. In order to mitigate the harmonic distortion, the performance of shunt active power filter (SAPF) is judged in terms of the accuracy and response time of its designed controller. In this context, the controller consists of three parts: harmonic extraction, switching control, and DC-link capacitor. The harmonic extraction technique serves the major role of deriving the required reference current to ensure successful mitigation of current harmonics by SAPF. Among the existing techniques, harmonic extraction algorithms based on time-domain approaches are most widely applied as they offer simple implementation features with increased speed and reduced computational burden. This paper presents detailed investigation and analysis regarding the performance of two famous time-domain harmonic extraction techniques namely, synchronous reference frame (SRF) and instantaneous power (PQ) theory. Extensive simulation work is conducted in MATLAB-Simulink platform under two conditions, which are, steady-state conditions and dynamic-state conditions, considering various highly nonlinear loads. For evaluation purposes, each control algorithm is incorporated into the controller of a three-phase SAPF, developed using a three-level neutral-point-clamped (NPC) inverter. Comprehensive results are provided to confirm mitigation performance of the SAPF utilizing each harmonic extraction algorithm.

This paper presents the simulation-based study and results of a three-phase shunt active power filter (SAPF) for power quality improvement. The power quality of the power systems is degraded because of the presence of non-linear loads at the consumer end. The SAPF can reduce the impact of harmonics caused by the non-linear loads. The analyzed SAPF system is modeled and simulated using MATLAB-Simulink workspace. The ultimate goal of this study is to improve the total harmonic distortion of the system as per the standards defined by IEEE-519.


2021 ◽  
Vol 1 (4) ◽  
pp. 23-29
Author(s):  
Adel Elgammal ◽  
Tagore Ramlal

Increased usage of combined PV-Wind renewable energy sources is seen as a positive step toward reducing air pollution and carbon emissions. However, since non-linear loads have increased dramatically, voltage quality and harmonic distortion concerns have arisen, affecting the operation of combined PV-Wind RES and smart-grid electrical transmission structures. This study shows how a Shunt active power filter may improve energy quality in a microgrid structure at the distribution level. The major goal of this article is to find an appropriate controller approach for improving the shunt active power filter's compensating capacity. This paper simulates a PV-Wind hybrid renewable energy system that operates in the presence of unpredictably variable solar and wind energy resources. The objective is to allow the construction of an electrical control structure that produces the right duty cycle. It will aid in the regulation and stabilization of voltages at dc/dc energy conversion plant. Simulation is used to assess the proposed control system's ability to enhance power quality. The device's compensating capability is mostly determined by the DC link capacitor voltage control. The closed loop functioning of a proportional integral controller is used to attain this voltage regulation in the past. To increase the functioning of a shunt active power filter, the MOPSO procedure approach has been presented. The performance of suggested approaches and the comparison of different pulse generating strategies have been validated in the SIMULINK/MATLAB model environment. The suggested technology successfully improves power quality on the grid and maintains a steady voltage on the grid despite variations in RE output and load.


2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Yap Hoon ◽  
Mohd Amran Mohd Radzi ◽  
Mohd Khair Hassan ◽  
Nashiren Farzilah Mailah

An enhanced harmonics extraction algorithm based on Instantaneous Power (PQ) Theory is proposed for indirect current controlled (ICC) three-level neutral point diode clamped (NPC) inverter-based shunt active power filter (SAPF). SAPF is famous in current harmonics mitigation for its flexibility in dealing with dynamic state conditions. As for its controller, PQ Theory has served the major role in harmonics extraction algorithm due to its simple implementation features. However, it suffers from serious time delay due to its dependency on sluggish numerical filters. Furthermore, the algorithm is mostly designed to suit the operation of direct current controlled (DCC) SAPF which requires the knowledge of actual SAPF current (injection current). This leads to inaccurate mitigation as the injection current does not possess the exact information on actual source current which suffers from switching ripples problems. Therefore, two major modifications are introduced involving the development of mathematical average algorithm to replace numerical filter for fundamental real power computation and the formation of mathematical current relationship to change DCC to ICC based operation. The proposed algorithm is developed and evaluated in MATLAB/Simulink. From the simulation results, significant improvement in terms of Total Harmonic Distortion (THD) and response time is presented in comparison to conventional algorithm.


Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1951
Author(s):  
Mihaela Popescu ◽  
Alexandru Bitoleanu ◽  
Mihaita Linca ◽  
Constantin Vlad Suru

This paper presents the use of a three-phase four-wire shunt active power filter to improve the power quality in the Department of Industrial Electronics of a large enterprise from Romania. The specificity is given by the predominant existence of single-phase consumers (such as personal computers, printers, lighting and AC equipment). In order to identify the power quality indicators and ways to improve them, an A-class analyzer was used to record the electrical quantities and energy parameters in the point of common coupling (PCC) with the nonlinear loads for 27 h. The analysis shows that, in order to improve the power quality in PCC, three goals must be achieved: the compensation of the distortion power, the compensation of the reactive power and the compensation of the load unbalance. By using the conceived three-leg shunt active power filter, controlled through the indirect current control method in an original variant, the power quality at the supply side is very much improved. In the proposed control algorithm, the prescribed active current is obtained as a sum of the loss current provided by the DC voltage and the equivalent active current of the unbalanced load. The performance associated with each objective of the compensation is presented and analyzed. The results show that all the power quality indicators meet the specific standards and regulations and prove the validity of the proposed solution.


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