Selective Harmonic Current Mitigation

with a Shunt Active Power FilterProject C0014-2014-03 247099 Institutional Links CONACYT-

British Council

Universidad Michoacana de San Nicolás de Hidalgo

Meeting April 6, 2016

División de Estudios de Posgrado de la Facultad de Ingeniería

Eléctrica

Motivation

Introduction

Detection methods

SAPF

Selective harmonic current compensation method

Conclusions

1. MOTIVACIÓN• In electric power systems are switched system introducing harmonic line mainly due to the switching elements.

•Harmonics generated from nonlinear loads, such as switch mode power converters and adjustable speed drives, as well as other unbalanced loads in distribution networks deteriorate power quality in power transmission and distribution systems. •Nonlinear loads increase losses and produce harmonic distortion in the grid.

•This harmonic distortion can be mitigated using passive filters.

•Thus, passive filters cannot always provide a complete compensation solution.

•As an alternative, different active filter solutions have been continuously analyzed in recent years. A conventional (APF) is typically composed of three single phase inverters and pulse width modulation (PWM) and can be connected to the load either in parallel or in series

INTRODUCTION

Algorithm Harmonic Detection MethodFrequency-domain Discrete Fourier Transform (DFT)

Fast Fourier Transform (FFT)Recursive Discrete Fourier Transform

Time-domain Synchronous harmonic dq-frameBand pass filtersInstantaneous power “pq theory” Generalized integrators

Other Prediction algorithms, Prony analysisKalman filtersNueral networks and adaptive controlWavelets Transform

Classification of the most used harmonic detection methods in APF’s

REFERENCE CURRENTS CALCULATOR BASED ON THE THEORY PQ

Schematic of SAPF

PRINCIPLE OF OPERATION OF AN ACTIVE FILTER

Components of an APF connected to a power system

Block diagram of the control circuit based on the APF-abc

Implementation of the APF in MatLab®

Topology of a shunt active power filter

Case Study

LOAD CURRENTS AND HARMONIC SPECTRUM

Selective harmonic current mitigation based of a Hybrid active power filter

Currents generated by the nonlinear load and unbalanced linear load.

Illustrates the current to be injected by the active filter. It may be noted that has a high harmonic content,

can be impractical in some systems

Extraction of the fundamental component for the APF

Results of the contribution of injection of the fundamental component current in the three-phase system

Harmonic spectrum for selective compensation the fifth harmonic

Selective compensation of fundamental component and fifth harmonic

Harmonic spectrum of source currents based on selective harmonic compensation

Conclusions•The simulation was conducted

based on a three-phase circuit with linear and nonlinear unbalanced loads. •Using the proposed SAPF resulted in a reduction of the original THD from 16.25% to 3.39% or nearly five times less.•The effectiveness of the proposed SHCM system makes it a practical solution for a variety of industrial applications with need harmonic current mitigation.

Thank You