Mohd Najib Mohd Hussain

Single-phase half-bridge shunt active power filter employing fuzzy logic control

This paper describes implementation of half- bridge shunt-active power filter incorporating voltage (VCL) and current control loop (CCL) that has resulted with a reduction in the number of switches in use as compared to a typical H-Bridge voltage source inverter topology. The proposed system is connected in parallel with the load and at normal condition it gives appropriate compensation to solve problems such as current displacement and harmonics. Active pulse width modulation technique with fuzzy logic control strategy is proposed for voltage control. The system has fast response and is capable of being subjected to load variations. Hysterisis current control is used to shape the input current with fuzzy logic control to regulate the DC bus voltage of the compensator.

Identification of Hammerstein-Weiner System for Normal and Shading Operation of Photovoltaic System

This paper present an identification of model system performance for Photovoltaic (PV) System under normal and shading operating condition in UiTM Pulau Pinang, Malaysia of 2.4 kW systems. A system identification approach was implemented by employing a Hammerstein-Weiner (HW) model as model structure. The approach concerned on the estimation of the photovoltaic system basis of observed data. The nonlinearity input and output are taken from irradiance and dc output current data of the real system severally. These data were used in Hammerstein-Weiner model to generate a black-box model structure which provides a flexible parameterization for nonlinear models. The best fit nonlinear model when using data from normal operating condition is when HW model incorporate with piecewise linear as the input channel and wavelet network estimators as output channel. For normal operation of PV system, the percentage of best fit was 96.51% by means of bn = 1, fn = 3, and kn = 2 of the linear model order. While the percentage best fit model generate considering shading effect was 86.32% with bn = 1, fn = 3, and kn = 1 of the linear model order. The modelling is implemented using system identification toolbox of Matlab software package.

Identification of Multiple Input-Single Output (MISO) model for MPPT of Photovoltaic System

This paper presents a modelling of Multiple Input-Single Output (MISO) model for tracking maximum point of Photovoltaic (PV) Systems. A system identification approach is used to obtain the model characteristics of existing structural systems through dynamic observations which incorporate with traditional direct control Maximum Power Point Tracking (MPPT) algorithm. The generate model characteristics was used in designing the MPPT of the Photovoltaic Systems. The need of an efficient mathematical model to characterize the dynamics system for PV is essential for implementing the system for control applications. In this paper, the transfer function relating the input parameters (Solar irradiance and cell temperature) and output parameter (DC current) of the PV module MF120EC3 was identify with the aid of MISO for Auto-Regressive with eXogenous input (ARX) model. The approach has concern on the estimation of the (Direct Current (DC) for photovoltaic system based on the real systems data from Pusat Tenaga Malaysia (Malaysia Energy Centre, MEC). A Fourth-order autoregressive (ARX) model using the ARX algorithm, (ARXQS) was chosen since the model output provide 93.42% best fit model criteria. The modelling is implemented using system identification toolbox of Matlab software.

Classification of Power Quality Disturbance Based on Continuous S-Transform-Windowing Technique (CST-WT) and ANOVA as a Feature Selection

This paper was conducted in order to identify and classify the different types of Power Quality Disturbances (PQD) based on a new approach the Analysis Of Variance (ANOVA). ANOVA is used as feature selection for the PQD parameters. The datum of PQD from the PSCAD/EMTDC® simulation and Power Quality Monitoring has been validated before feature extraction analysis can be commenced. The obtained datum is then analyzed by using Windowing Technique (WT) based on Continuous S-Transform (CST) to extract the features and its characteristics. Moreover, the study focuses an important issue concerning the identification of PQD selection, detection and classification. The feature and characteristics of three types of signal such as sag, swell, and transient signal are obtained. The outcome of the analysis shows that a new approach framework ANOVA-Based Before and After Neural Network (NN) classification has a slightly increases to 15-25% in term of classification of PQD.

A dsPIC Microcontroller Based System Identification of Positive Output Buck Boost Converter for Module Mismatch Application

An identification system of multiple-input single-output (MISO) model is developed in controlling dsPIC microcontroller of positive output buck-boost (POBB) converters for module mismatch condition of photovoltaic (PV) system. In particular, the possibility of the scheme is to resolve the mismatch losses from the PV module either during shading or mismatch module occurrences. The MPPT algorithm is simplified by identification approach of indirect incorporated with a simple incremental direct method to form a combined direct and indirect (CoDId) algorithms. Irregular consumption of solar irradiation on a PV module shall step-up or step down the voltage regarding to the desired DC output voltage of POBB converter. This optimized algorithm will ensure that the PV module to kept at maximum power point (MPP), preventing power loss during module mismatch incident in PV module especially during partial shading condition. The simulation and laboratory results for PV module of polycrystalline Mitsubishi PV-AE125MF5N indicate that the proposed model and development of PV system architecture performs well, while the efficiency up to 97.7% at critical of low solar irradiance level. The controlling signal is based on low-cost embedded microcontroller of dsPIC30F Digital Signal Control (DSC).

Harmonic reduction using current injection based twelve-pulse rectifier

A twelve-pulse rectifier structure will apply the current injection method which automatically generated in order to reduce the total harmonic distortion (THD) for the three-phase diode rectifier. The twelve pulse operation applying of three-phase diode rectifier, two additional diode, two transformers with low VA rating and simple zig-zag transformer will be designed to achieve the low THD. The losses in the current injection system considerably affect the input current THD and volt-ampere ratings of applied magnetic circuit. The zig-zag transformers are used as a current injection device to provide low-leakage impedance for the current harmonics generated, resulting in pure sinusoidal input current in the three-phase diode bridge rectifier.