Harmonic Distortion Levels Research Articles

Advanced Harmonic Analysis in Industrial Power Systems: Its Impact on Enhancing Power Quality and System Performance

This paper presents an advanced harmonic analysis of industrial power systems, focusing on its impact on enhancing power quality and system performance. The study investigates the harmonic distortions caused by nonlinear loads, particularly those introduced by Variable Frequency Drives (VFDs), in a manufacturing plant. Measurements of key electrical parameters, such as voltage, current, and Total Harmonic Distortion (THD), were recorded and analysed. The results reveal significant harmonic distortion levels, exceeding industry standards, which can lead to reduced equipment efficiency and potential damage. By adhering to IEEE 519 guidelines and implementing harmonic mitigation strategies, such as filters and power factor correction, the paper demonstrates how power quality can be improved. The findings provide a foundation for future simulation and optimization efforts aimed at reducing harmonic distortion and enhancing system performance. Keywords: Total Harmonic Distortion (THD), Harmonic Analysis, Power Quality, Industrial Power Systems, Current Distortion.

Performance analysis of a new single-phase transformerless PV inverter structure based on a buck-boost converter

A single-phase inverter based on a buck-boost converter is increasingly used in modern power electronics, particularly in solar photovoltaic systems. Unlike traditional inverters that utilize transformers to electrically isolate the solar system from the power grid, this transformerless design enhances efficiency, reduces weight, and lowers costs. However, the absence of a transformer introduces challenges related to Electromagnetic Compatibility (EMC) and the potential for increased leakage currents, which must be carefully managed to ensure system safety and performance. In this paper, the performances of a new configuration of a single-phase transformerless PV inverter based on a dc-dc buck-boost converter is proposed and analyzed. Since it is the only switch (mosfet) in the DC-DC converter that operates at high frequency, and it is controlled by pulse width modulation (PWM) to adjust the output voltage. This allows for flexible voltage conversion, enabling the inverter to either step up (boost) or step down (buck) the input voltage as needed. Therefore, switching losses can be significantly reduced to improve efficiency and reduce electromagnetic interference of the single-phase inverter structure. In order to demonstrate the EMC performances and evaluate the leakage current of the proposed structure, an EMC model is developed under the Simscape-MATLAB/Simulink environment, this model offers an EMC analysis including the prediction of leakage current over a frequency range from 100 Hz to 2 MHz. The results clearly showed that the level of the Total harmonic distortion (THD), as well as the levels of leakage current, are below the requested EMC standards.

Design of a optimal robust adaptive neural network-based fractional-order PID controller for H-bridge single-phase inverter

Adaptive Neural Network- based Fractional-order PID Control (NN-FO-PID) approach is designed for H-bridge inverter. This inverter has an LC filter to decrease the level of Total Harmonic Distortion (THD) that can affect the efficiency of the system. In addition, the reduction of THD and stability insurance of the filter are challenging performances. To fulfill this function, a fractional order proportional integrated derivative (FO-PID) controller is developed for the inverter. A few merits of the Fractional-Order notion as a useful technique include reduced sensitivity to noise and parametric fluctuation; however, for a wider range of disturbances, such as noise, this approach shows an unsuitable practical application based on its fixed gain values. Moreover, having parameters uncertainties including parametric variations, load uncertainty, supply voltage variation uplifts this challenging condition severely, and the parameters need to be adjusted once more for more dependable operations. As a result, the control parameters must be optimized once more to provide ideal operations. Here, an adaptive mechanism is proposed based on neural network structure to optimize the gains of the FO-PID controller for better performances. In real applications, this approach has some benefits, since it uses the Black-box technique, which does not necessitate a precise mathematical model of the system, resulting in a reduced computational burden, simple implementation, and reduced dependence on the model’s states. Even under extremely difficult circumstances, the artificial neural network structure effectively optimizes the FO-PID gains in real-time. This benefit can reduce the amount of THD-level for the inverter, properly. Additionally, to have a proper response in the first step condition, and trying to reduce the level of dangerous conditions, based on benefits of the ant lion optimization method, it is considered to select the initial values of the FO-PID controller gains. Here to verify the superiority of the proposed controller, PID and FO-PID controllers are offered to drive a comparison with this method, which are optimized using the PSO optimization algorithm. The analysis of simulation data shows that the suggested control strategy is appropriate for maintaining stability as well as adequately compensating for disturbances and uncertainties in the inverter. Furthermore, with the help of this controller, THD level decreased lower than 2 percent.

SUIVI DE LA QUALITÉ DE PUISSANCE MAXIMALE D'UN GÉNÉRATEUR D'INDUCTION À DOUBLE ALIMENTATION BASÉ SUR UN CONTRÔLEUR DE RÉSEAU NEURONAL ARTIFICIEL POUR SYSTÈME DE CONVERSION D'ÉNERGIE ÉOLIENNE

Renewable energy sources are playing a crucial role in satisfying the upcoming energy source needs for the world. The current power system is power electronics converter based, with several non-linear loads and spotted generations of renewable energy sources, resulting in many power quality issues. Most existing research analyzed MATLAB simulations and presented a high Total Harmonics Distortion (THD) level. This research work proposed an artificial neural network (ANN) control technique for a doubly fed induction generator (DFIG) based wind energy conversion systems (WECSs). To decrease chattering phenomena during the excitation arrangement, an advanced controller works for adaptive modification of the irregular power gain, even preserving the strength of the closed-loop scheme. The proposed PI controller one step forward improves reliability and tracks maximum voltage from the pulse width modulation rectifier. At primary, the modeling of the DFIG was presented. Then, using the proposed ANN controller, the rotor magnitude was tuned to recognize vector control of active and reactive power. The converter intends to activate at unity power factor and provide input currents with adequate harmonic content. The interface between the power’s electronic converter and the DFIG pulls out the most real power potential. The proposed prototype hardware model and simulation results are verified.

Switching-mode audio amplifier based on a ΔΣ A/D converter

The article describes the design and implementation of a modular hardware platform intended for testing and measuring various configurations of switching-mode audio amplifiers based on sigma-delta modulation. Two single-channel power amplifier modules were designed and manufactured, along with a stereophonic module serving as the basic source of modulated signals. Additionally, measurements were conducted on the fundamental parameters of the completed amplifier, such as harmonic distortion level, dynamic range, and output power. The developed platform serves as a foundation for modifications and further advancement in the technology of building switching-mode audio amplifiers.

Mitigation of Harmonics Due to Electric Vehicle Charging

The increasing adoption of electric vehicles (EVs) has led to an increase in demand for charging infrastructure. However, EV charging can introduce harmonic distortion into the electrical distribution network, causing power losses, reduced efficiency, and equipment damage. This project developed an EV charging system with harmonic reduction to ensure a stable and efficient charging process. The research methodology allowed the team to develop an EV charging system with harmonic reduction that was effective in reducing the total harmonic distortion (THD) level from 56.3% to 1%. The system was also found to be stable and efficient during charging. The findings of this project have the potential to make a significant contribution to the development of EV charging infrastructure. The proposed system can help to mitigate the negative impacts of EV charging on the electrical distribution network, while also ensuring a stable and efficient charging process.

Improve the voltage profile of the grid-integrated induction motor with a fuzzy-based voltage source converter

This article suggests installing a series compensator on grid-connected induction motors that allows for the ride-through of unbalanced voltage sag. Fuzzy logic controls the motor voltages in a standard three-phase voltage source inverter or voltage source inverter (VSI). An open-ended three-phase machine and the grid form a series connection for the VSI. The proposed system is well suited for uses where frequency variation is unnecessary, such as with large pumps or fans. There is no requirement for a direct current (DC) source or injection transformer when conducting an electric mutual coupling The severity of the sag in the grid voltage that will prevent EMC from shutting down is proportional to the load on the motors. An increase in the voltage of the DC link may be necessary if the voltage is not balanced. A 1.5 hp four-pole induction motor was used alongside grid voltage disturbances to test the proposed compensator's ride-through capability. Grid's current analysis demonstrates that the proposed system does not require the addition of a passive filter to achieve low levels of total harmonic distortion (THD). Additionally, the control strategy, component ratings, and analysis of the converter's output voltage operating principle and pulse width modulation technique are covered. The system's viability is shown via simulation and experimental results.

Harmonics Assessment of Distribution Transformer with Photovoltaic Integration and Unbalanced Loads

Harmonic distortion is one of the monumental power quality problems in an electrical power system. It frequently originated from non-linear loads generating non-sinusoidal steady state waveforms, which may lead to various undesirable effects on distribution transformers such as increased losses, overheating and lifetime reduction. In previous works, the harmonic current contributions from non-linear loads from consumers have been appointed as the main contributor of harmonic issues in the distribution transformers. However, since the integrations of renewable energy as a distributed generation (DG) have exponentially increasing in recent years, the impact of solar photovoltaic (PV) system implementation into distribution system on amplifying additional harmonic contents also needs to be addressed. Therefore, this paper conducts a comparative analysis of voltage and current harmonic profiles within the distribution transformer in three-phase distribution network and three-phase grid-connected photovoltaic (GCPV) system, with both subjected to supply unbalanced non-linear loads. The simulation is carried out using MATLAB Simulink 2021a software and the results are compared according to standards. As a result, the distribution transformer in the GCPV system is proven to contain higher levels of voltage and current harmonic distortion compared to a normal distribution grid.

The Implementation of Space Vector PWM in 36-Pulse D-STATCOM for Power Quality Improvement

Introduction: This paper addresses the ongoing challenge of harmonics reduction in power systems, particularly focusing on Flexible AC Transmission Systems (FACTS) devices. Instead of employing a conventional multilevel converter, an alternative configuration is proposed: a 36-pulse gate turn-off thyristor-based converter (GTO-VSC). This converter comprises three 12-pulse Voltage Source Converters (VSCs) as fundamental units, operating collectively on the frequency mode of GTO switching control within a Distribution Static Synchronous Compensator (D-STATCOM). The D-STATCOM dynamically compensates reactive power in the system. The 36-pulse configuration results in AC output voltage waveforms containing harmonics such as the 35th, 37th, 71st, 73rd, etc., leading to higher total harmonic distortion (THD) levels. background: Reduced number of switches in flexible AC transmission. Method: In response, the paper presents a new model featuring a 3-level, 36-pulse, 25kV, ±3MVAr STATCOM configured with 12-pulse GTO-VSCs. This model incorporates PWM gate switching and employs a PI-control methodology to optimize harmonics in simulation, specifically targeting harmonics at the 35th, 37th, 71st, 73rd, etc., orders using Sim Power Systems toolbox in Math Works software. Result: The compensator's operational performance is controlled through switching angle optimization, which minimizes harmonics, regulates voltage, and manages reactive power in the electrical transmission system. Conclusion: The simulation results demonstrate that the proposed model is acceptable for enhancing the flexibility and performance of the FACTS device in mitigating harmonics in power systems.

Robust adaptive backstepping control of H‐bridge inverter based on type‐2 fuzzy optimization of parameters

AbstractA type‐2 fuzzy logic‐based adaptive backstepping control (T2FABSC) approach is designed for an H‐bridge inverter. This inverter has an LC filter to decrease the level of total harmonic distortion (THD) that can affect the efficiency of the system. Reduction of THD and stability insurance of the filter are challenging trade‐offs, tackled here by a controller design. The performance, however, is not suitable for actual applications under a wider range of disturbances, and the parameters need to be adjusted once more for more dependable operations. Backstepping control is given a Lyapunov definition‐based adaptive mechanism that can improve this scheme's stability and robustness in the face of numerous disturbances. Additionally, the system is viewed as a “Black box” without the need for a precise mathematical model, which might lead to a lighter computing burden and simpler implementation. Moreover, a fuzzy type‐2 structure is adopted that can optimize the gains of the adaptive Backstepping controller (ABSC) in challenging conditions. The antlion optimization algorithm is employed to optimize the parameters of the membership functions in the fuzzy system, hence improving the performance of the controller. In addition, compared with different optimization algorithms, it can more quickly and accurately locate the best solutions. Finally, the findings of both the simulations and the experimental outputs are examined, proving the T2FABSC's significant robustness and faster dynamics in a variety of challenging circumstances.

Evaluation of LVRT capability and stability analysis of VSC based advanced control approach for grid connected PV system under grid fault conditions

Short circuit faults are a prevalent issue in power systems, causing disruptions to the grid's normal operation. Dynamic behaviours of the conventional power systems during short circuit faults have been extensively studied and understood. The bulk of ongoing research and development are focusing on the dynamic performance of grid-connected renewable energy systems under these fault conditions, due to changes in the grid code and a decrease in system inertia. The development of effective control strategies to enhance the system's reliability during fault conditions is of paramount importance. In this paper, a two-stages grid-connected photovoltaic system (GCPV) having a rated power of 2 MW was created in the MATLAB/Simulink environment. The dynamic behaviour of the presented system was evaluated in two scenarios: steady state conditions and short circuit faults. A line-to-ground short circuit fault was created at the grid side, and its effect on the PV system's operation was observed. An advanced control system was designed to maintain stability during fault conditions. The results demonstrated the efficiency of the designated control system in minimizing the effects of short circuit faults on the GCPV system's function, and restoring the system promptly after the fault was cleared. Furthermore, considering modifications in grid regulations, the low voltage ride through (LVRT) capability of the designed system was analysed and validated according to the UK standards. The Total Harmonic Distortion (THD) level at the common coupling point was also analysed for voltage and current, remaining below the acceptable level of 5% as specified in the IEEE Std. 519.

Probabilistic and Harmonic Assessment of Power Quality Parameters from Distributed Energy Resources in a Distribution Network

Distributed energy resources (DERs) are leading actors in energy transition worldwide. Despite the environmental benefits, DERs are intermittent (consumption/generation power changes according to the input variables), and the use of power electronic devices affects the power quality in distribution networks. Typically, models and simulations (deterministic or probabilistic) are proposed to estimate such impacts. However, previous studies have analyzed the main effects caused by one or two DERs during a day. These studies had a reduced level of detail in the applied methodology in modeling and impact evaluation, or they did not consider that the harmonic distortion level depends on input variables. The aim of this article was to develop a probabilistic harmonic simulation approach to characterize the hourly effect of photovoltaic systems (PVS), battery energy storage systems, and electric vehicle charging stations in a 34-node IEEE test feeder. The individual and collective effect estimation of the DERs consists of the hourly quantification of the effective voltage value, voltage unbalance, power factor, and harmonic distortion, with data obtained using Python and PowerFactory co-simulation for 23 operation scenarios. These impacts were assessed through indicators proposed in the literature and hypothesis tests (inferential statistics). Each DER generally operates at a specific time, making it easy to identify the individual effects of network parameters. The PVS increased the effective voltage value and total harmonic distortion. However, electric vehicles and batteries increase the voltage unbalance and power factor due to the two-phase connection in some network nodes.

Analysis of the Energy Quality in a Building Acclimated Through a System of Evaporative Cooling Operated by Frequency Converters.

The present article has as the aim to analyze the level of harmonic distortion of voltage in the bus in an electric system in the presence of evaporative refrigerators used for the cooling of environments operated by converters of frequency in which measurement campaigns were carried out in field. Considering that the frequency converters with the filters absence make the system presents nonlinear characteristics whose analyses are of great matter in what concerns about the quality of the electric energy and the fulfillment of the law and the existing rule, established by the national and international regulating agencies. In this context, through computational simulations, there was observed the efficiency of the passive filters tuned with objective to reduce the levels of harmonic distortions of voltage in the bus in study and to adapt these levels to the standards of reference contained in the existing resolutions. 1

Estimating the potential for conservation of electrical energy in the residential sector of Manaus AM/Brazil, from the power quality evaluation

This work is a study of electricity supplied to residential customers in the city of Manaus-AM/Brazil. We selected three residential consumers with profiles of different loads, of which were collected data concerning the quality of the energy used in homes. The research made use of a tool, the analyser of power quality, KEW 6310. On the basis of procedures for electricity distribution by ANEEL, which provides for minimum requirements for energy (voltage and frequency) we compared the results of the evaluation in selected consumers, where, from the point of view of the network voltage and frequency, the minimum levels laid down by ANEEL are serviced. However, are observed significant levels of harmonic distortion of currents on consumers in study. Finally, it is shown the impact caused by these distortions in the elevation of consumption and the estimation of energy conservation in the residential sector.

Investigating the Power Quality of an Electrical Distribution System Stressed by Non-Linear Domestic Appliances

: Power quality has become a matter of growing concern in recent years owing to a daily rise in use of non-linear loads at domestic level. In addition, fast growing technologies like distributed generation and electric vehicles are emerging as part of modern distribution systems. Therefore, it is necessary to evaluate and analyze the power quality issues due to various non-linear home appliances to give a clear picture of the current scenario. So that future technologies can be accommodated in the distribution systems while coping with existing power quality issues. The experimentally developed harmonic models, of various commonly deployed domestic appliances, are used for the simulation of a practical distribution system in Electrical Transient Analyzer Program (ETAP). Experimental results combined with simulation results show an alarmingly high level of harmonic distortion, breaching the recommended standard practices, in both current and voltage at not only point of common coupling (PCC) but also at the consumer’s end. In addition to increase in losses, this also degrades power factor giving rise to distortion power. While discussing other impacts of harmonic distortion, true power factor (PFtrue) and distortion power (D) has also been evaluated at PCC.

Metodology for harmonic distortion level determination

In order to make an equitable application of bonuses or extra charges due to harmonic distortion, it is necessary to separate between harmonics exported by nonlinear loads used by costumers, and imported ones due to distortion at Point of Common Coupling (PCC) property of the electric utility. On this paper, a new methodology is presented to assign each costumer his own distortion. Same sampling instrumentation applied in charging electrical bills —with new software— registers total exported harmonic current, making possible determination of corrected non-sinusoidal apparent power and equivalent power factor during an invoicing period. Some effects of nonlinear loads on grids are determined and analyzed, and experiments done on compact fluorescent lamps are shown and described. ss

SIMULATION MODEL OF AN ADARTIVE DIGITAL FILTER BASED ON THE LEAST SQUARES METHOD

In accordance with contemporary requirements in the fields of mobile and embedded telecommunications and electronics, there is a growing need for faster, smaller, and energy-efficient digital electronic devices (DEDs). These devices include microcontrollers, digital signal processors, and programmable logic integrated circuits (FPGAs).
 Utilizing DEDs involves the hardware execution of advanced digital signal processing (DSP) algorithms tailored to the specific architecture of the electronic device. To expedite the design process when directly implementing DSP algorithms in hardware, simulation models are generated to facilitate optimizing the design during the creation of the programming component for FPGAs.
 The paper discusses the outcomes of an investigation into an adaptive filter (AF) model that relies on the recursive least squares method (RLS). During the simulation, an analysis of the time and frequency parameters of the AF model was conducted. It was determined that the quality of the filtering process reaches a plateau at the 28th order, and further increasing the AF order does not lead to a significant improvement in signal filtering. Instead, it results in an increased demand for hardware resources. Furthermore, during the verification of the proposed simulation model, an AF-based noise reduction system was simulated. The total harmonic distortion (THD) level for the built-in AF unit was found to be 1.05 % that serves as confirmation of the effectiveness of the developed AF unit.
 Therefore, through this investigation, the most suitable order for the AF has been identified. This choice will enable a more effective utilization of FPGA resources when implementing the AF in hardware. The study results validate the accuracy and effectiveness of the hardware-centric simulation model developed, while also demonstrating the hardware-oriented architecture of the adaptive RLS filter for its forthcoming implementation on FPGA.

Extended Kalman Filter design for sensorless sliding mode predictive control of induction motors without weighting factor: An experimental investigation.

Due to their simplicity, cheapness, and ease of maintenance, induction motors (IMs) are the most widely used motors in the industry. However, if they are not properly controlled, the load torque and motor speed will fluctuate in an unsatisfactory fashion. To effectively control the load torque and speed of these IMs, it is necessary to use specialized drives. The entire system (IMs + Drives) will experience uncertainty, nonlinearities, and disruptions, which calls for an outstanding performance control structure. The sensorless sliding mode predictive torque control (SSM-PTC) for both AC-DC converter and DC-AC inverter, which are utilized for feeding the IM, is investigated in this work. The AC-DC converter is controlled using the SSM-PTC method in order to follow the DC-link reference voltage throughout any changes in the operating point of the IM. While the DC-AC inverter is controlled using a sensorless predictive power control (SPPC). Within a unity power factor, this SPPC regulates the reactive power flow between the motor and the supply to account for the undesirable harmonic components of the grid current. In addition, an experimental performance improvement of SSM-PTC of IM supplied by a 5-leg AC-DC-AC power converter using extended Kalman filter (EKF) without weighting factor (WF) is also studied in this work. Design and implantation of the suggested control systems are performed using a dSPACE 1104 card. The experimental results of the proposed converter control demonstrate that the suggested approach effectively regulated the DC link, reducing load torque and speed fluctuations. In the context of inverter control, a prompt active power response yields a motor current waveform that resembles a sinusoidal pattern, exhibiting minimal levels of harmonic distortion.

To Study Impact Of Electric Vehicle Charging On Power Quality On Various Loads

Electric Vehicles (EVs) are a clean energy alternative to gas and energy powered vehicles. They form a crucial part of the present and future automotive. Electric vehicles being non-linear loads could affect the power quality of the grid. In this paper, we present a view of the fluctuations in power factor and Total Harmonic Distortion (THD) levels when varying number of electric vehicles (two wheeler and four wheeler) are connected to the power system .The system was simulated and studied in Simulink. Here, a captive power plant that is supplying power under base load and peak load conditions is considered.

A novel Prairie Dog Optimization Algorithm (PDOA) based MPPT controlling mechanism for grid-PV systems

<p>Recently, the solar photovoltaic (PV) systems are increasingly used in many application systems, due to their efficiency and cost-effectiveness. Still, extracting the maximum energy from PV panels under varying climatic conditions is one of the most significant problems. For this purpose, various optimization based MPPT controlling mechanisms are developed in the conventional works for obtaining the maximum energy yield. However, it suffers with the major problems of low convergence, computational burden, high time consumption to reach the optimal solution, and lack of efficiency. Therefore, this research work objects to implement a novel and recently developed optimization technique, named as, Prairie Dog Optimization Algorithm (PDOA) for MPPT controlling. With superior tracking efficiency and enhanced speed, it helps to extract the greatest power from the PV panels. In order to manage the output of PV with less switching stress and loss, a high gain interleaved SEPIC DC-DC converter is also used. A better power quality is ensured by using the voltage source inverter to lower harmonic distortion levels. The significance of the proposed study is to develop a novel optimization based MPPT controlling technique to obtain the maximum energy yield form the PV panels. The PDOA technique is not previously used for power extraction and MPP tracking, due to its intelligent best optimum solutions with high convergence, the proposed work uses the PDOA technique to optimally identify MPP. Also, the voltage boosting and conversion is performed with the use of high gain interleaved SEPIC converter with increased efficiency. Performance study evaluates and compares the simulation outcomes and the efficacy of the suggested regulating topology using a variety of metrics, including IV & PV characteristics, output voltage, output power, THD, grid output, peak time, settling time, and others.</p>