Shunt Active Power Filter untuk Meredam Harmonisa Beban Non-Linear Satu Fasa

Penggunaan beban non-linear semakin umum digunakan seiring berkembangnya teknologi yang menerapkan komponen elektronika daya di dalamnya. Beban non-linear dapat menimbulkan harmonisa pada jaringan listrik dan mengakibatkan penurunan kualitas daya. Cara yang dapat digunakan untuk mengatasi permasalahan ini salah satunya adalah dengan menggunakan Active Power Filter. Pada penelitian ini suatu Shunt Active Power Filter (SAPF) untuk sistem satu fasa didesain dan disimulasikan untuk meredam harmonisa yang timbul karena penggunaan beban non-linear satu fasa yang sering digunakan di skala rumah tangga. Teori ip-iq dan kontrol PI untuk tegangan DC digunakan untuk mendapatkan referensi arus kompensasi. Pada simulasi, beban yang digunakan berupa penyearah dioda yang dihubungkan ke beban RL seri. Hasil simulasi menunjukkan bahwa sebelum pemasangan SAPF, nilai THD arus sumber mencapai 32.63%. Sedangkan setelah pemasangan SAPF nilai THD arus sumber yang dihasilkan hanya sebesar 4.47%. SAPF yang disimulasikan memiliki kemampuan peredaman harmonisa sebesar 28.16% dan dapat memenuhi standar yang ditoleransi oleh IEEE 519-2014

A NOVEL METHOD FOR DESIGNING THE CONTROLLER OF A LCL-FILTER-BASED GRID-CONNECTED INVERTER WITH CONSIDERING VARYING SYSTEM PARAMETERS

Exactly determining the control coefficients for the controller of a three-phase LCL-filter-based inverter is an important and challenging issue in microgrid systems. However, existing LCL-filter-based inverter systems usually assume that all system parameters are determined accurately and remain constant over time, which is not true in real situations. Variations in the system parameters are known to possibly seriously degrade the performance of LCL-filter-based inverter systems. For efficiency and robustness, this paper proposes a novel method for the generalized controller design of a three-phase LCL-filter-based grid-connected inverter system that can address deviations in system parameters. An optimum way to determine the stability bounds under various system parameters cases is introduced. The assessment of the stability bounds is based on the Routh criterion by solving the characteristic equation of the closed-loop control system. Simulations results are presented to validate the correctness and effectiveness of the proposed design method

Design of LCL-filters for grid-connected voltage source inverters

LCL-filters are preferred over conventional L-filters for grid-connected voltage source inverters (VSI) due to their superior harmonic attenuation, smaller filter size and weight. The LCL-filter design process is complex and takes an iterative approach due to the coherence between the filter parameters and design requirements. The main aim of this thesis is to analyse different design variables that contribute to an efficient LCL-filter. The study carried out, falls under two sections. The first study was to understand the importance of ratio between the grid-side and inverter-side inductors, resonance frequency, reactive power production and attenuation of higher order harmonics in an LCL-filter. Based on the analysis, this thesis proposes a generalised LCL-filter design algorithm which avoids uncertainty in determining resonance frequency as the exact position of the resonance frequency is determined based on the design requirements. The proposed design method considers the LCL-filter as a single filtering unit rather than individual filtering contributions from passive components. The second study is extended to understand the limits of passive components based on the reactive power production limits (based on control structure), IEEE-519 harmonic limitations and the allowable switching losses or voltage drop across the entire filter. Based on the analysis, the thesis proposes an optimum operating point for an LCL-filter where the minimum inductance is realised to meet IEEE-519 harmonic current limitations for a given reactive power production while ensuring reasonable switching losses. Simulations and experimental results are presented to demonstrate the efficacy of the proposed two methods in terms of total harmonic distortion, harmonic attenuation and reactive power compensated.[Please note: This thesis file has been deferred until December 2016