Mitigation Of Harmonic Distortion Research Articles

Utilizing Artificial Neural Network For the Regulation Of Electric Springs In Renewable Systems

Now a days the research work is going on to improve the performance of electric springs (ESs) by integrating a current source inverter (CSI) and a neural network controller. A new ES configuration that includes CSIs is introduced to enhance ES functionality. This configuration is accompanied by a control strategy that involves direct current control and mitigation of harmonic distortion, like the methods used in active power filters (APFs). By transitioning from voltage source inverters (VSIs) to CSIs and integrating a neural network controller, a significant reduction in total harmonic distortion (THD) can be achieved. The paper presents two distinct control loops, each equipped with proportional-integral (PI) controllers. One loop is focused on regulating the Critical load voltage (CL voltage), while the other is specifically designed for reactive power compensation.

Mitigation of harmonic distortions in third rail electrical systems

<span lang="EN-US">The extensive use of power electronic converters in the third rail system increases the harmonic distortions on the rail electrical feeding systems. Electrical machines and transformers could be overheated causing premature failures of the devices. It is therefore important to address the harmonic distortions on the electrical networks during real-time operation, which includes the degraded operation, not just the normal operation. In this paper, the harmonic distortions of a third rail system are investigated using electrical transient and analysis program (ETAP) simulation software. Four operating scenarios, namely the normal operation and three degraded operations, are considered in the studies. The degraded operations occur when one of the bulk supply transformers or 33 kV feeders is out of service. The findings of the studies showed that the 11<sup>th</sup> and 13<sup>th</sup> order harmonics are the dominant harmonic orders due to the use of 12-pulse rectifiers on the third rail system. Single-tuned harmonic filters are designed and placed in the 33 kV feeders to mitigate the individual voltage harmonic distortion (IHD<sub>v</sub>) and the total voltage harmonic distortion (THD<sub>v</sub>) so that it is within the statutory of IEEE 519:2014.</span>

Novel Mathematical Design of Triple-Tuned Filters for Harmonics Distortion Mitigation

The design of AC filters must meet the criteria of harmonic distortion mitigation and reactive power support in various operating modes. The stringent reactive power-sharing requirements currently lead to sophisticated filter schemes with high component ratings. In this regard, triple-tuned filters (TTFs) have good potential in harmonic mitigation of a broad range of harmonics. In the literature, the TTF design has been presented using a parametric method, assuming that the TTF is equivalent to a three-arm single-tuned filter (TASTF). However, no direct methods of designing it or finding its optimal parameters have been provided. This paper presents novel mathematical designs of TTFs. Three different design methods are considered—the direct triple-tuned filter (DTTF) design method, as a TASTF, and a method based on the equivalence between the two design methods called the equivalence hypothesis method to design the triple-tuned filter (EHF). The parameters of the three proposed design methods are optimized based on the minimization of a proposed multi-objective function using a recent metaheuristic algorithm called artificial rabbits optimization (ARO) to mitigate harmonics, improve power quality, and minimize power losses in an exemplary system presented in IEEE STD-519. Further, the system’s performance has been compared to the system optimized by the ant lion optimizer (ALO) and whale optimization algorithm (WOA) to validate the effectiveness of the proposed design. Simulation results emphasized harmonics mitigation in the system, the system losses reduction, and power quality improvement with lower reactive power filter ratings than conventional single and double-tuned filters.

Mitigation of Harmonic Distortions in Third Rail Electrical Systems: A Case Study in Malaysia

Mitigation of Harmonic Distortions in Third Rail Electrical Systems: A Case Study in Malaysia

Designing of Three Level 3 Phase Inverter Using Improved SPWM Modulation for different Loads

Many high voltage applications require three-phase inverters. The major challenge in inverter designing is the mitigation of harmonic distortion (HD) to achieve better inverting performance. Usually, sinusoidal pulse width modulation (SPWM) is widely used to trigger the inverting switches for controlling the total HD performance in the inverter. To provide the option of multiple operating ranges the multilevel inverters are designed for higher voltage operations. This paper contributes in two passes, first, an improved SPWM modulation is generated for designing the three levels inverter. Then in the second pass, the performance of the THD is evaluated under the different load conditions using V-I measurement. THD is present in the system due to the use of switches. Therefore, this paper has evaluated the performance of the proposed improved SPWM based multilevel inverter for analysis. In order to improve the performance, the modulation index of the SPWM block is varied. The performance of the component report is also presented in the short..the output waveform of the line current and the voltage are compared; The FFT analysis is done to evaluate the comparison of THD performance. It is concluded that improving the SPWM performance and the lording conditions may improve the THD performance also.

Mitigation of Harmonic Distortion of AC Voltage of the Source Caused by DC Drives commutation Notches

The wide use of power electronics in speed control of DC drives creates commutation notches in AC supply voltage of the source. In this paper a standalone generator of 150 KVA is feeding a variable speed DC drives of 75 KW is studied and a single tuned passive filter is designed to mitigate the notches in supply voltage to be compliance with IEEE Std519:2014.

Discontinuous-PWM Method for Multilevel $N$-Cell Cascaded H-Bridge Converters

The cascaded H-bridge converter (CHB) is a very suitable solution with inherent modularity for many applications such as flexible ac transmission systems and motor drives. In this article, the discontinuous pulsewidth modulation (DPWM) by clamping some power cells is used in the CHB because it permits to reduce the switching losses in the power devices. However, this provokes a high harmonic distortion (basebands and sidebands harmonics) in the CHB output voltage compared with the quality obtained avoiding to clamp cells, just applying the conventional phase-shifted PWM (PS-PWM) technique. This has been studied for the three-cell CHB topology but the extension for an N-cell CHB with several clamped cells is a challenge that is addressed in this article. A generalized CHB harmonic voltage analysis applying the DPWM method is presented considering multiple clamped cells. The harmonic distortion mitigation target can be decoupled into two objectives. The proposed method cleverly groups the cells (one clamped + one or two nonclamped cells) to mitigate the basebands harmonic distortion. Simultaneously, a variable-angle PS-PWM technique is applied to the CHB in order to mitigate the sidebands harmonics content. Experimental results demonstrate the good performance of the proposed method.

Mitigation of Harmonic Distortion in a Power System Feeding Nonlinear Loads Using Shunt Passive Single Tuned Filters

In this paper a distribution system of 2 MVA, 11 KV standalone generator is feeding a group of six branches of pulse width modulation (PWM) drive nonlinear loads, such a distribution power system is used in oil fields drilling rigs, each branch is fed through a step down transformer of 11/0.4 KV and of capacity proportional to its branch load rating. For this group of nonlinear loads, the total current harmonic distortion (ITHD) and total voltage harmonic distortion (VTHD) are calculated at the point of common coupling (PCC#1) which show that the system failed to meet IEEE Std 519 harmonic limits. A shunt passive single tuned filters are designed to mitigate (ITHD) and (VTHD). The addition of these filters to this power system were effective in making it compliance with IEEE Std 519.

Design and simulation of techniques for mitigation of harmonic distortion in a three-phase rectifier

Rectifiers are electrical devices that receive an alternating signal and deliver a direct current signal at their output, this process by which they transform one type of energy to another is known as rectification. This type of device incorporates a phenomenon called harmonic distortion into the electrical network, which consists of malformations presented in the waveform of the alternating signal from which it feeds, which generate unwanted effects on electrical systems. Because of this, this work presents the combination of two harmonic distortion mitigation strategies (12-pulse multilevel converter and harmonic frequency tuned filtering stage) in order to reduce total harmonic distortion levels generated by a three-phase rectifier.

Hybrid BBO-PSO-based extreme learning machine neural network model for mitigation of harmonic distortions in micro grids

Microgrid tends to be the cluster of some of the renewable energy sources. The most important research area in the power distribution system side is the improvement in the quality of power delivered to the end users. This paper focuses on enhancing the power quality of the microgrid system; shunt active power filters (SAPF) is employed at the distribution side and to design an appropriate controller that achieves a better compensation for the considered SAPF. It is to be noted that the compensation methodology is dependent on the regulation process of the DC-link voltage. Traditionally, this regulation process is carried out employing a closed loop proportional-integral controller. In this paper, a hybrid biogeography-based optimisation – particle swarm optimization-based extreme learning machine neural network model is proposed to design the compensation for the SAPF and to mitigate the harmonics so that effective power gets delivered through the grid.

Hybrid BBO-PSO-based extreme learning machine neural network model for mitigation of harmonic distortions in micro grids

Hybrid BBO-PSO-based extreme learning machine neural network model for mitigation of harmonic distortions in micro grids

Power Quality Improvement with Mitigation of Harmonic Distortion in Three-phase System Based on Shunt Active Power Filter Mechanism

In response to rising business cost and global environmental concerns, this research proposes a mechanism to improve power quality by reducing total harmonic distortion (THD) in three-phase three-wire system using shunt active power filter (SAPF). Three control algorithms are utilized to achieve a reduction in THD: DC-link capacitor voltage, hysteresis current, and harmonic extraction algorithms. The proposed SAPF mechanism is ideal for small-scale businesses and residential projects keen on energy conservation and natural resources preservation. In the study, simulations were carried out using MATLAB/Simulink. To verify, a prototype was fabricated and experiments were undertaken. The simulation and experimental results are in good agreement. The proposed SAPF mechanism could reduce THD of the system from 41.47% to 15.07%.

VSI Based DSTATCOM for Compensating Nonlinear and Unbalanced Loads

This paper presents study of distribution static compensator (D-STATCOM) for compensation of neutral current, source&PCC current harmonic distortion, PCC voltage regulation and compensation of unbalanced current waveform for the three phase four wire nonlinear and unbalanced load medium voltage distribution system. The proposed control algorithm is developed based on synchronous reference frame theory with PI controller. The obtained reference current signal from control algorithm is compared in hysteresis band current controller for better switching of D-STATCOM. The performance of system without & with D-STATCOM is also analysed and compared. The proposed control method is implemented on 11/0.4kv medium voltage distribution system and it is provided effective compensation for reactive power and harmonic distortion mitigation. The simulation results are obtained using MATLAB/SIMULINK.

Design of PI and Fuzzy Logic Controllers for Distribution Static Compensator

<span>This paper presents study of distribution static compensator (D-STATCOM) for compensation of reactive power, harmonic distortion mitigation and load balancing in three phase three wire nonlinear load distribution system. The proposed control algorithm is developed based on synchronous reference frame theory using PI and FUZZY logic controller. The obtained reference current signal from control algorithm is compared in hysteresis band current controller for better switching of D-STATCOM. The performance of DSTATCOM with PI and fuzzy logic controller is also analysed and compared for DC voltage regulation and harmonic distortion mitigation .The proposed method is provided effective compensation for reactive power, harmonic distortion mitigation and load voltage balancing. The simulation results are obtained using MATLAB/SIMULINK soft ware.</span>

Suppression of parallel resonance and mitigation of harmonic distortion through shunt active power compensation

Abstract In this contribution a solution to the parallel resonance problem that can be present in practical applications of shunt Active Power Filter (APF) compensation is proposed. The proposed solution involves turning the shunt APF scheme of compensation into a Shunt Hybrid Filter (SHF) configuration. A Linear Quadratic Regulator (LQR)-based switching controller was specifically designed for this hybrid scheme of compensation, maintaining stringent performance requirements on the tracking of filtering currents and the draining of the harmonic ripple currents. Results obtained with Matlab/Simulink® illustrate an effective and sound system of compensation which also reduces the necessary KVA rating of the APF.

Power Control of Grid-Connected Converters Under Unbalanced Voltage Conditions

This paper presents a grid current control technique on the power converter level. The submitted analysis deals with a control method of positive and negative current sequences in a grid-connected converter during voltage sags. The control method should assure the proper exchange of active and reactive powers without power ripple, the mitigation of harmonic distortion of grid currents, and should also enable the control of grid current peaks. A simple expression is determined, which allows estimation of maximum active and reactive powers exchanged between the grid and the converter without exceeding the admissible converter current. Some simulation and experimental results are reported to validate the theoretically predicted performance of the control strategy.

Mitigation of Harmonic Distortion in Microgrid System Using Adaptive Neural Learning Algorithm Based Shunt Active Power Filter

Abstract This paper presents the enhancement of power quality for a microgrid system at distribution level using Shunt active power filter. The main objective of this paper is to identify a suitable controller technique for obtaining a better compensation capability of shunt active power filter. The compensation capability of the device is mainly depends on the regulation of DC link capacitor voltage. Conventionally this voltage regulation is achieved by the closed loop operation of PI controller. To raise the performance of shunt active power filter, neural learning algorithm technique has been proposed here. The comparison of different pulse generation technique and the performance of proposed techniques have been verified in the platform of MATLAB/SIMULINK model.

Mitigation Of Harmonic Distortion By Power Electronic Interface Connecting Distributed Generation Sources To A Weak Grid

In this paper a Power Electronic Interface (PEI) that integrates up to two renewable energy sources is presented. The power flow of the different distributed sources is controlled through the DC link and the AC terminal voltage of the voltage source converter (VSC) adjustment. The local sources can be controlled to supply electricity to the local load and export the exceeding energy to the grid. The system is analyzed under distorted grid voltage in order to discuss the effectiveness of different compensation strategies. Solutions based on resonant passive filters and on the injection of harmonics to compensate the voltage grid distortion are presented.

Frequency domain modelling and identification of nonlinear loads using a least error squares algorithm

Nonlinear electric loads result in harmonics in voltages and current waveforms. This has prompted the need for more accurate models for these loads, in order to allow accurate prediction and mitigation of harmonic distortion. This paper presents a general methodology for modelling electric loads, in the frequency domain, in the presence of harmonics. The proposed method is based on a least squares parameter estimation algorithm and requires advance knowledge of the harmonic contents of load voltage and current waveforms. The residual current, which results from the incomplete extraction of the parameters due to the mismatch between the voltage and the current waveforms, is also calculated. It has been found that the order of the load transfer admittance, as well as the number of its parameters to be identified depend on the number of harmonics common between the voltage and current waveforms. The proposed algorithm is tested using actual recorded data.