Alireza Javadi

A Single-Phase Active Device for Power Quality Improvement of Electrified Transportation

A transformerless hybrid series active filter is proposed to enhance the power quality in single-phase systems with critical loads. This paper assists the energy management and power quality issues related to electric transportation and focuses on improving electric vehicle load connection to the grid. The control strategy is designed to prevent current harmonic distortions of nonlinear loads to flow into the utility and corrects the power factor of this later. While protecting sensitive loads from voltage disturbances, sags, and swells initiated by the power system, ridded of the series transformer, the configuration is advantageous for an industrial implementation. This polyvalent hybrid topology allowing the harmonic isolation and compensation of voltage distortions could absorb or inject the auxiliary power to the grid. Aside from practical analysis, this paper also investigates on the influence of gains and delays in the real-time controller stability. The simulations and experimental results presented in this paper were carried out on a 2-kVA laboratory prototype demonstrating the effectiveness of the proposed topology.

Experimental Investigation on a Hybrid Series Active Power Compensator to Improve Power Quality of Typical Households

In this paper, a transformerless hybrid series active filter using a sliding-mode control algorithm and a notch harmonic detection technique are implemented on a single-phase distribution feeder. This method provides compensation for source current harmonics coming from a voltage fed type of nonlinear load (VSC) and reactive power regulation of a residential consumer. The realized active power filter enhances the power quality while cleaning the point of common coupling (PCC) from possible voltage distortions, sags, and swells initiated through the grid. Furthermore, to overcome drawbacks of real-time control delay, a computational delay compensation method, which accurately generates reference voltages, is proposed. Based on an improved compensation strategy, while the grid current remains clean even with a small compensation gain, voltage disturbances initiated by the power system are obstructed by the compensator, and the PCC became free of voltage harmonics and protected from sag and swell. Simulation and experimental results carried on a 1.6-kVA prototype are presented and discussed.

A novel transformerless hybrid series active filter

This paper proposes a novel configuration of Series hybrid active filters. The proposed configuration could be connected to the grid without requiring a costly series injection transformer. This topology is capable of compensating current harmonics at the source and voltage distortion at the point of common coupling. Furthermore, an appropriate controller could compel the Transformerless hybrid series active filter (THSeAF) to perform as Unified power quality conditioner (UPQC) with quazi-similar behavior. The transformerless configuration is more cost-effective than any other series compensators based mostly on a transformer to inject the compensating voltages. Moreover, as a dynamic voltage regulator, the latter will compensate unwanted harmonics, unbalances, sags, and swells at terminals of a sensitive load. When performing as a series hybrid active filter, it cleans the power system from current distortions together with harmonics and unbalances, similar to a shunt active filter. The detailed operation of the proposed topology is presented and analyzed. Modeling and controller design are given. Validation by simulations of the system dynamic for different load and supply conditions is presented.

Power Quality Enhancement of Smart Households Using a Multilevel-THSeAF With a PR Controller

In this paper a multilevel transformerless hybrid series active filter is proposed to enhance the power quality of a single-phase residential household. The proposed topology reflects new trends of consumers toward electronic polluting loads and integration of renewable sources which in fact may lead to the scope of a reliable and sustainable supply. This paper contributes to improvement of power quality for a modern single-phase system and emphasis integration of a compensator with energy storage capacity to ensure a sustainable supply. A proportional resonant (P+R) regulator is implemented in the controller to prevent current harmonic distortions of various non-linear loads to flow into the utility. The main significant features of the proposed topology include the great capability to correct the power factor as well as cleaning the grid simultaneously, while protecting consumers from voltage disturbances, sags, and swells during a grid perturbation. It investigates aspects of harmonic compensation and assesses the influence of the controllers choice and time delay during a real-time implementation. Combinations of analysis and experimental results performed on a laboratory setup are presented for validation.

An advanced control algorithm for Series hybrid active filter adopting UPQC behavior

This paper presents an advanced comprehensive control approach for Hybrid Series Active Filter (HSeAF). This configuration consists of a series active filter (SeAF) and a shunt passive filter. The proposed control strategy, make this topology capable of compensate current distortions at the source and voltage harmonics and related issues from the load point of common coupling (PCC). The controller compels the HSeAF to perform as Unified power quality conditioner (UPQC) with similar behavior. The control algorithm employs the synchronous reference frames and the p-q theory to create an advanced controller for HSeAFs. This proposed algorithm treats diverse power quality issues simultaneously. With a fast and accurate response, it makes the PCC more reliable, cleans the power system from any current distortions, and also corrects the power factor. Hence, in this paper, the proposed control approach is studied and analyzed by simulations.

Series active conditionners for reliable Smart grid: A comprehensive review

The development of active power compensators and power conditioners lead to eminent solutions to improve power quality. Among these emerging solutions, the Series Active Filter is relatively immature compared to shunt and hybrid configurations. This paper presents a comprehensive review of the Series compensator history, configurations, control strategies, and related involvements in this field. It provides a perspective of Series active compensators technology to researchers dealing with power quality issues. This paper tries to promote industrial application of series compensators for future Smart grids.

Unfunctionality of the instantaneous p-q theory for the control of series active filters

Proliferation of power electronics converters and electronic equipments has dramatically increased electric pollution in electrical distribution power systems. The distorted current draw by these nonlinear loads distorts the supply voltage which may then give rise to harmonic currents at distribution networks, even when at these locations no harmonic generating equipment is present. Furthermore, voltage unbalances, sags, and swells are other power quality issues related to the supply voltage required to be considered for compensation. Consequently, the use of active filters as an affordable solution for power quality is indispensable. These devices increase the efficiency and sustainability of modern power systems and can also help higher penetration of renewable fluctuating power into the network. Subsequently, many theories have been developed to control active filters and then perform compensation of unwanted harmonics, unbalances, sags, and swells. Depending on the issues, the control algorithms employed in series active filters differ. However, the majority of those algorithms deal with proportional integrator PI or PIDs which create a delay in the compensation. To eliminate this delay the latest approaches try to integrate the instantaneous compensation theory in Series active filters. This time domain approach was proposed by Akagi [1] under the name “p-q theory” or “instantaneous power theory”. It is the most widely spread theory for three-phase shunt active filters. This paper discusses the application of the mentioned theory for the control of series active filter and to evaluate its efficiency in a typical network using SimPowerSystems tools of MATLAB‥

A single-phase transformerless active filter with reduced DC-link voltage

This paper proposes a Hybrid series active filter (HSeAF) without interfacing transformer. The compensator improves power quality issues of a single phase system. A control algorithm to compensated current harmonics of a nonlinear load to propagate into the single-phase system, while protecting loads from voltage perturbations initiated from the power system is studied. The exclusion of the series transformer reduces complexity and overall costs of this configuration. The compensation of current harmonics and load voltage distortions are analyzed together with the influence of gain and delays in the controller stability. The detailed operation of the proposed topology is presented and analyzed in a comparative study with conventional series active filters. Validation by simulations of the system dynamic for different load and supply conditions is presented.

Stability analysis and effects of dampers on Series active compensator

Although, series compensators including dynamic voltage restorer and series active filters in general are considered reliable, a stability analysis of their configuration and their control algorithm is mandatory before their large propagation in the power system. The stability study of three-phase controllers applied in drives and Active filters seems complex and unusual. Thus, this paper presents a comprehensive approach to evaluate the stability of a typical control algorithm by means of Laplace transforms in frequency domain. Furthermore, the paper focus on the stability of LC filters implemented in series compensators to eliminate high frequency harmonics of the power converter. Then, the effect of passive dampers is evaluated. This frequency domain interpretation of three-phase passive filter could be used in stability analysis of various three-phase systems. Moreover, simulation and experimental results are presented to validate the theoretical approach.

Power Quality Device for Future Household Systems with Fast Electric Vehicle Charging Station

This paper investigates on power quality improvement of Smart residential buildings with Electric vehicle charging station. A multilevel Transformerless Hybrid Series Active Filter (THSeAF) is proposed to address power quality issues related to both current and voltage. The proposed configuration assists integration of renewable energy sources to ensure a sustainable supply. The controller is based on a two separated single-phase proportional plus resonant (PR) regulator to prevent current harmonic distortions of various non-linear loads to flow into the utility. The proposed topology is able to instantly correct the power factor as well as cleaning the grids current, while protecting consumers from voltage disturbances, sags, and swells during a grid perturbation. Aspects of harmonic compensation and voltage restoration for a 120/240V residential system are analyzed along with the proposed solution to overcome power quality issues.