Field results on developed three-phase four-wire shunt active power filters

Abstract-This paper presents three-phase four-wire Shunt Active Power Filters with ability to compensate current harmonics, power factor, and current unbalance. The power stage of the Active Power Filters is based on a two-level four-leg inverter. The switching technique is based on an optimized periodic sampling strategy, and the digital controller uses the Theory of Instantaneous Reactive Power (p-q Theory) expanded for three- phase four-wire systems. The presented Active Power Filters were successfully demonstrated in four different facilities. The presented experimental results show the performance of the Active Power Filters in operation with very different load profiles

Design of robust current tracking control for active power filters

The paper describes a design methodology for robust current-tracking control of active power filters using quantitative feedback theory (QFT). The design aim is to address system issues of power quality and power factor correction in a double-sided converter (rectifierhverter combination) subject to parametric uncertainty, non-linear dynamic behavior and exogenous disturbances. The paper includes simulation results to demonstrate the dynamic performance attributes afforded to the resulting closed-loop control system, and to verify the design procedure

Comparison of three control theories for single-phase active power filters

Active Power Filters have been developed in last years, mostly for three-phase systems applications. The use of Shunt Active Power Filters on single-phase facilities brings many benefits for the electrical grid, since these installations have non linear loads and power factor problems, and in their total, they are responsible by a significant portion of the total electric energy consumption. Harmonics and reactive power consumed by single-phase installations cause additional power losses on the electrical grid. So, mitigate harmonics at the origin helps reducing these extra losses and other problems caused by the harmonics. The drawback of this solution is the necessity of a large number of Active Power Filters distributed by the generality of the single-phase facilities. So, it becomes necessary a simple and low cost Shunt Active Power Filter to install on single-phase installations. This paper presents three simple control theories to use on single-phase Shunt Active Power Filters. Simulation and experimental results comparing the three different control theories are presented and analyzed.Fundação para a Ciência e a Tecnologia (FCT

Active Power Filters in Zero Energy Buildings

Master's thesis Renewable Energy ENE500 - University of Agder 2017With an increasing focus on the environment and moving from fossil to renewable energy, there has and is an increasing interest in zero energy buildings. Zero energy buildings often utilize local intermittent renewable energies such as wind and solar energy, and are going to play an important role in the smart grid development with their distributed generation and energy storage etc. In Southern Norway, the smart village Skarpnes is utilizing building integrated photovoltaic systems and is developed for studying zero energy buildings and its impact on electricity demand and power quality. Power electronic based equipment such as uninterruptible power supplies, adjustable speed drives, personal computers and more have all enhanced our daily lives by providing an efficient and reliable way of utilizing the electrical energy. Because of their non-linear behaviour, they are responsible for harmonic currents causing additional losses and harmful effects. In this thesis, a shunt active power filter based on the instantaneous power theory used for power quality improvement is studied. This involves harmonic current, reactive power and neutral current compensation, where load data is obtained from the smart village Skarpnes project. Investigating the operation of the shunt active power filter during import and export of power, during load changes and operation during distorted and unbalanced utility voltage. Based on simulations using MATLAB/Simulink the three-phase, four-wire shunt active power filter is able to compensate the harmonic currents, reactive power and neutral current. The total harmonic distortion in the source current after compensation is below limits proposed by the Institute of Electrical and Electronics Engineers Standard 519-2014 for all test case

A new configuration for shunt active power filters

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.This thesis presents a new power circuit configuration to be used in shunt active power filters. A new control algorithm based on the linear voltage control suitable for the proposed circuit is introduced. The system is analysed both in time and frequency domains. The practical implementation of the system proves its suitability for the proposed task. The switching frequency of the proposed circuit is much lower than that in other active filters. The switching losses are then considerably reduced, in addition to the fact that the switching devices can withstand larger values of currents being switched on and off at lower frequencies which is an advantage to this circuit. The component sizes (capacitors and inductors) in the proposed circuit are also much smaller than those in other filter configurations. In addition, the thesis presents a new method for categorising the active filter systems proposed in the surveyed literature. The survey includes a comparison of these techniques showing their respective merits and drawbacks. The thesis also includes an implementation of a reference current generator that is suitable for single-phase applications without the need for excessive computations. The technique involves a modified Fourier analysis, which is suitable for active filtering applications

Comparison of different optimization criteria for optimal sizing of hybrid active power filters parameters

Praise Worthy Prize granted a permission for Brunel University London to archive this article in BURA.Harmonic distortion in power systems has increased considerably due to the increasing use of nonlinear loads in industrial firms and elsewhere. This distortion can give rise to overheating in all sectors of the power system, leading to reduced efficiency, reliability, operational life and sometimes failure. This article seeks to propose a new methodology for the optimal sizing of hybrid active power filter (HPF) parameters in order to overcome the difficulties in hybrid power filters design when estimating the preliminary feasible values of the parameters. Sequential Quadratic Programming based on FORTRAN subroutines is used to find out the planned filter size in two different optimization criteria depending on design concerns. The first criterion is to minimize the total voltage harmonic distortion. The second one is to maximize the load power factor, while taking into account compliance with IEEE standard 519-1992 limits for the total voltage harmonic distortion and the power factor.The effectiveness of the proposed filter is discussed using four exemplary case

Design and implementation of a modified fourier analysis harmonic current computation technique for power active filters using DSPs

The design and implementation of a harmonic current computation technique based on a modified Fourier analysis, suitable for active power filters incorporating DSPs is presented. The proposed technique is suitable for the monitoring and control of load current harmonics for real-time applications. The derivation of the basic equations based on the proposed technique and the system implementation using the Analogue Devices SHARC processor are presented. The steady state and dynamic performance of the system are evaluated for a range of loading conditions

Digital Current-Control Schemes

The paper is about comparing the performance of digital signal processor-based current controllers for three-phase active power filters. The wide use of nonlinear loads, such as front-end rectifiers connected to the power distribution systems for dc supply or inverter-based applications, causes significant power quality degradation in power distribution networks in terms of current/voltage harmonics, power factor, and resonance problems. Passive LC filters (together with capacitor banks for reactive power compensation) are simple, low-cost, and high-efficiency solution