DC Bus Voltage Regulation of an Active Power Filter Using a Fuzzy Logic Controller

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.

Download Full-text

Design and Analysis of an Improved Approximated Fuzzy Logic Controller for Shunt Active Power Filter

International Journal of Fuzzy System Applications ◽

10.4018/ijfsa.2012070105 ◽

2012 ◽

Vol 2 (3) ◽

pp. 69-89 ◽

Cited By ~ 1

Author(s):

Rambir Singh ◽

Asheesh K. Singh

Keyword(s):

Fuzzy Logic ◽

Fuzzy Logic Controller ◽

Dynamic Performance ◽

Active Power Filter ◽

Active Power ◽

Computational Time ◽

Absolute Deviation ◽

Shunt Active Power Filter ◽

Power Filter ◽

Reactive Compensation

This paper presents the design and analysis of an improved approximated simplest fuzzy logic controller (IASFLC). A cascade combination of simplest 4-rule fuzzy logic controller (FLC) and an nth degree polynomial is proposed as an IASFLC to approximate the control characteristics of a 49-rule FLC. The scheme is based on minimizing the sum of square errors between the control outputs of a 49-rule FLC and a simplest 4-rule FLC in the entire range of universe of discourse (UOD). The coefficients of compensating polynomial are evaluated by solving instantaneous square error equations at various test points in the entire UOD. This IASFLC maps the output of a 49-rule FLC with absolute deviation of less than 5%. The proposed IASFLC is used to control the dc link voltage of a three phase shunt active power filter (APF). A detailed analysis is performed during transient and steady state conditions to check power quality (PQ) and dynamic performance indices. The performance of proposed IASFLC is compared with a 49-rule FLC and approximated simplest fuzzy logic controller (ASFLC) based on minimization of the deviation at central values of membership functions (MFs). It is found comparatively better for harmonic and reactive compensation with a comparable dynamic response. The memory requirement and computational time of proposed IASFLC are less than the ASFLC.

Download Full-text

An Improved Double Fuzzy PI Controller For Shunt Active Power Filter DC Bus Regulation

International Journal of Power Electronics and Drive Systems (IJPEDS) ◽

10.11591/ijpeds.v6.i2.pp337-347 ◽

2015 ◽

Vol 6 (2) ◽

pp. 337

Author(s):

Nabil Elhaj ◽

Moulay Brahim Sedra ◽

Tarik Jarou ◽

Hind Djeghloud

Keyword(s):

Active Power Filter ◽

Active Power ◽

Positive Sequence ◽

Shunt Active Power Filter ◽

Power Filter ◽

Synchronous Reference Frame ◽

Source Voltage ◽

Dc Bus ◽

Bus Voltage

This paper targets to demonstrate the importance of the choice of the algorithm references detection to be applied with a double fuzzy PI corrector (DFPI) for the control and the regulation of a shunt active power filter (SAPF) DC bus voltage. In a previous work, the synchronous reference frame (SRF) algorithm was applied and gave satisfactory results. In the present paper, the SRF is substituted by the positive sequence of the fundamental of the source voltage algorithm (PSF) which offered better results regarding the power quality of the considered main utility feeding a variable DC RL load throughout a diode bridge. The results were carried out using computer simulation perfomed under MATLAB/Simulink environment. To make the obtained results more convenient, a comparison between the couples (SRF, PI), (PSF, PI), (SRF, DFPI), (PSF, DFPI) is added to prove the effectiveness of the couple (PSF, DFPI) in satisfying the compromise between a good regulation of the SAPF DC bus voltage and a good quality of filtering resulting in an improved quality of power.

Download Full-text