scholarly journals Enhanced Instantaneous Power Theory with Average Algorithm for Indirect Current Controlled Three-Level Inverter-Based Shunt Active Power Filter under Dynamic State Conditions

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.

“The increased penetration of Distributed Energy Resources (DER) is inspiring the entire design of conventional electrical power system. “A Microgrid (MG) includes distributed generation, loads, energy storage, and a control system that is competent of working in grid-connected mode and/or islanded mode. Power quality (PQ) problems are one of the major technical challenges in MG power system. To get better PQ of energy supply, it is essential to analyze the harmonics distortion of the system. Moreover, harmonic distortion in a MG networks has significantly reduced PQ, which affects the stability of the system. In order to diminish the harmonics, shunt active power filter (SAPF) has been extensively useful and it is verified to be the best solution to current harmonics. The present paper proposes the mitigation of harmonics of a MG system using shunt active power filter (SAPF). However, the SAPF is employed for reimbursing the harmonics concurrently in the distribution system. The proposed model is developed in MATLAB/Simulink and the result obtained validates the superiority of proposed technique over others in terms of harmonics elimination.”


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.


2014 ◽  
Vol 2014 ◽  
pp. 1-20 ◽  
Author(s):  
Suksan Tiyarachakun ◽  
Kongpol Areerak ◽  
Kongpan Areerak

This paper presents a novel harmonic identification algorithm of shunt active power filter for balanced and unbalanced three-phase systems based on the instantaneous power theory called instantaneous power theory with Fourier. Moreover, the optimal design of predictive current controller using an artificial intelligence technique called adaptive Tabu search is also proposed in the paper. These enhancements of the identification and current control parts are the aim of the good performance for shunt active power filter. The good results for harmonic mitigation using the proposed ideas in the paper are confirmed by the intensive simulation using SPS in SIMULINK. The simulation results show that the enhanced shunt active power filter can provide the minimum %THD (Total Harmonic Distortion) of source currents and unity power factor after compensation. In addition, the %THD also follows the IEEE Std.519-1992.


2014 ◽  
Vol 15 (2) ◽  
pp. 177-194 ◽  
Author(s):  
Anup Kumar Panda ◽  
Ranjeeta Patel

Abstract In this paper, shoot-through current elimination DC–AC converter circuit has been presented with the application of active power filter (APF). The intuitive analysis of the shoot-through in the conventional DC–AC converter has been reported first. Interleaved buck (IB) converter is adopted to eliminate the shoot-through current, thereby increasing the reliability of the interleaved buck–based active power filter (IB-APF). The 3-phase 4-wire IB-APF eliminates the current harmonics produced by the load just as a conventional one does and are innately immune to “shoot-through” phenomenon, with the elimination of special protection features required in conventional inverter circuits. A comparison has been made about the compensation capabilities of the IB-APF with the PI and fuzzy logic controller (FLC) used by id–iq control strategy under different supply voltage conditions. The id–iq control strategy used for extracting the three-phase reference current for IB-APF, evaluating their performance here in MATLAB/Simulink environment and also implemented using real-time digital simulator hardware (OPAL-RT hardware). The RTDS result verifies that the total harmonic distortion percentage of the source current can be reduced below 5% according to IEEE-519 standard recommendations on harmonic limits.


2017 ◽  
Vol 79 (4) ◽  
Author(s):  
Sajid Hussain Qazi ◽  
Mohd Wazir Mustafa ◽  
U. Sultana ◽  
Nayyar Hussain Mirjat

The quality of power nowadays is of great concern due to increasing demand of supply and energy resources are limited, another cause is increasing penetration of nonlinear loads in the power system. In order to overcome energy supply challenges, the focus of technologists is shifting to the renewable energy side such as the wind and solar energy and so on. As such, mitigating effect of nonlinear loads have become ever important as well. In this context, various techniques have been used by researchers in past decades. Shunt active power filter (APF) have long been used to mitigate current harmonics from fixed wind turbine generator (WTG). In this study shunt APF has been applied with variable speed WTG using synchronous reference frame (SRF) for the extraction of compensation signal for APF. Gate driver signals are generated from Bang-Bang Controller (Hysteresis Band Current Controller HBCC). A MATLAB/SIMULINK based Model have been developed. The Simulation results show decreased THD levels of the system and clearly suggest the effectiveness of Shunt APF in meeting the IEEE-519 standard recommendation for harmonic levels in WTG.


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