scholarly journals A New Optimal Current Controller for a Three-Phase Shunt Active Power Filter Based on Karush–Kuhn–Tucker Conditions

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6381
Author(s):  
Krzysztof Kołek ◽  
Andrzej Firlit
Keyword(s):  
Negative Impact ◽  
Active Power Filter ◽  
Pi Controller ◽  
Active Power ◽  
Shunt Active Power Filter ◽  
Power Filter ◽  
Current Controller ◽  
Optimal Value ◽  
Optimal Current ◽  
Hardware Platforms

This paper presents an algorithm for finding the optimal control for a current controller that operates as a part of a control system of a shunt active power filter. The algorithm is based upon the Karush–Kuhn–Tucker conditions for finding an optimal value where control signal is limited and constraints create a cube. The explicit solution of the Karush–Kuhn–Tucker problem is presented and simplified calculations are given to lower calculation complexity. The presented Karush–Kuhn–Tucker algorithm is compared with a classical PI controller. It is given the algorithm for finding the optimal parameters of the PI controller and the behavior of the PI controller is compared with the presented algorithm. Attention has been paid to the saturation of controllers in commutation states of load currents, which has a negative impact on the final performance of the controllers and the controlled shunt active power filter. The paper also presents the software and hardware platforms applied to run the presented algorithms in real-time. For both controllers, the shunt active power filter response is shown using real experimental results. The results of the experiments prove better behavior regarding the presented algorithm, especially in the case of commutative load currents, where the output signals from other regulators become saturated.

CURRENT HARMONICS MITIGATION FROM GRID CONNECTED VARIABLE SPEED WIND TURBINE DUE TO NONLINEAR LOADS USING SHUNT ACTIVE POWER FILTER

2017 ◽  
Vol 79 (4) ◽  
Author(s):  
Sajid Hussain Qazi ◽  
Mohd Wazir Mustafa ◽  
U. Sultana ◽  
Nayyar Hussain Mirjat
Keyword(s):  
Wind Turbine ◽  
Active Power Filter ◽  
Active Power ◽  
Variable Speed ◽  
Nonlinear Loads ◽  
Shunt Active Power Filter ◽  
Current Harmonics ◽  
Power Filter ◽  
Current Controller ◽  
Synchronous Reference Frame

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.

Approximated Simplest Fuzzy Logic Controlled Shunt Active Power Filter for Current Harmonic Mitigation

2013 ◽  
pp. 155-171
Author(s):  
Rambir Singh ◽  
Asheesh K. Singh ◽  
Rakesh K. Arya
Keyword(s):  
Fuzzy Logic ◽  
Fuzzy Logic Controller ◽  
Active Power Filter ◽  
Pi Controller ◽  
Active Power ◽  
Rule Base ◽  
Shunt Active Power Filter ◽  
Harmonic Compensation ◽  
Power Filter ◽  
Harmonic Mitigation

This paper examines the size reduction of the fuzzy rule base without compromising the control characteristics of a fuzzy logic controller (FLC). A 49-rule FLC is approximated by a 4-rule simplest FLC using compensating factors. This approximated 4-rule FLC is implemented to control the shunt active power filter (APF), which is used for harmonic mitigation in source current. The proposed control methodology is less complex and computationally efficient due to significant reduction in the size of rule base. As a result, computational time and memory requirement are also reduced significantly. The control performance and harmonic compensation capability of proposed approximated 4-rule FLC based shunt APF is compared with the conventional PI controller and 49-rule FLC under randomly varying nonlinear loads. The simulation results presented under transient and steady state conditions show that dynamic performance of approximated simplest FLC is better than conventional PI controller and comparable with 49-rule FLC, while maintaining harmonic compensation within limits. Due to its effectiveness and reduced complexity, the proposed approximation methodology emerges out to be a suitable alternative for large rule FLC.

Adaptive Method for Power Quality Improvement through Minimization of Harmonics Using Artificial Intelligence

2017 ◽  
Vol 8 (1) ◽  
pp. 470 ◽  
Author(s):  
P. Thirumoorthi ◽  
Raheni T D
Keyword(s):  
Artificial Intelligence ◽  
Power System ◽  
Power Quality ◽  
Active Power Filter ◽  
Pi Controller ◽  
Active Power ◽  
Shunt Active Power Filter ◽  
Power Filter ◽  
Non Linear ◽  
Source Current

Power system harmonics are a menace to electric power system with disastrous consequence. Due to the presence of non linear load, power quality of the system gets affected.  To overcome this, shunt active power filter have been used near harmonic producing loads or at the point of common coupling to block current harmonics. The shunt active power filter is designed to minimize harmonics in source current and reactive power in the non linear power supplies which are creating harmonics. In this paper, Instantaneous power of p-q theory is employed to generate the reference currents and PI controller is used to control the dc link voltage. In addition to this, Artificial Intelligence (AI) technique is used to minimize the harmonics produced by nonlinear load. The main objective of this paper is to analyze and compare THD of the source current with PI controller and by artificial neural network based back propagation algorithm. The proposed system is designed with MATLAB/SIMULINK environment.

Approximated Simplest Fuzzy Logic Controlled Shunt Active Power Filter for Current Harmonic Mitigation

2011 ◽  
Vol 1 (4) ◽  
pp. 18-36 ◽  
Author(s):  
Rambir Singh ◽  
Asheesh K. Singh ◽  
Rakesh K. Arya
Keyword(s):  
Fuzzy Logic ◽  
Active Power Filter ◽  
Pi Controller ◽  
Active Power ◽  
Computational Time ◽  
Rule Base ◽  
Shunt Active Power Filter ◽  
Harmonic Compensation ◽  
Power Filter ◽  
Harmonic Mitigation

This paper examines the size reduction of the fuzzy rule base without compromising the control characteristics of a fuzzy logic controller (FLC). A 49-rule FLC is approximated by a 4-rule simplest FLC using compensating factors. This approximated 4-rule FLC is implemented to control the shunt active power filter (APF), which is used for harmonic mitigation in source current. The proposed control methodology is less complex and computationally efficient due to significant reduction in the size of rule base. As a result, computational time and memory requirement are also reduced significantly. The control performance and harmonic compensation capability of proposed approximated 4-rule FLC based shunt APF is compared with the conventional PI controller and 49-rule FLC under randomly varying nonlinear loads. The simulation results presented under transient and steady state conditions show that dynamic performance of approximated simplest FLC is better than conventional PI controller and comparable with 49-rule FLC, while maintaining harmonic compensation within limits. Due to its effectiveness and reduced complexity, the proposed approximation methodology emerges out to be a suitable alternative for large rule FLC.

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