Harmonic Mitigation Research Articles

A Switched Z-Source and Switched Capacitor Multi-Level Inverter Integrated Low Voltage Renewable Source for Grid Connected Application

Most of the renewable sources generate power at lower voltage levels in the range of 20-50V which cannot be utilized by the loads. Therefore, stacking multiple modules in series increases the voltage level or using conventional boost converter or QZSis helpful. However, due to series stacking and boost converter or QZS there is a great power loss and also have reliability issues.The QZS inverter has very less boosting gain in the range of 2times. Theconventional boost converter or QZSis replaced with SZSC for voltage boosting and inverter operation. The SZSC boosts the voltage 4-5 times to the input voltage level. For further mitigation of harmonics, the conventional 6-switch inverter is replaced with switched capacitor MLI. Multiple renewable sources are at the input which include PV array, battery unit and PMSG wind module. The battery unit is a support to the renewable sources PV array and wind module. The DC link voltage stability is achieved by the battery unit placed in parallel to the renewable sources. The renewable sources share power to the grid through the SZSC and switched capacitor MLI. For DC voltage stability a CV control is integrated to SZSC. And for synchronized power sharing to the grid, a grid voltage feedback synchronization control is included for the control of MLI. A low rating renewable system is modelled and integrated to grid using Simulink MATLAB software. A comparative analysis is carried out operating the system with QZS and SZSC. The performances of the SZSC and MLI are evaluated by the graphs generated by the simulation of the modelled system.

Critical Analysis of Active Filter for Harmonic Reduction under Varying Load

In this paper, we give the main focus on the proliferation of non-linear loads in power systems, the mitigation of harmonics has become a critical concern to ensure stable and efficient operation. This study presents an analysis of an advanced control active filter (ACAF) designed for harmonic reduction under varying load conditions. The ACAF is a sophisticated solution that employs advanced control algorithms to effectively suppress harmonics and maintain power quality. The research investigates the performance of the ACAF under varying load conditions, which represent real-world scenarios where power consumption fluctuates. A comprehensive analysis is conducted to evaluate the filter's ability to adapt and maintain harmonic suppression efficiency across different load profiles. The study considers various load scenarios, including steady-state operation, transient load changes, and dynamic load fluctuations. The findings of this research contribute to the understanding of advanced control active filters in practical power systems with non-linear loads and varying operating conditions. The analysis provides valuable insights into the design, optimization, and implementation of ACAFs for harmonic mitigation, ultimately improving power quality and system reliability in modern electrical networks. A classified list of 38 publications on this topic is also given for the quick reference.

Adaptive TS-ANFIS neuro-fuzzy controller based single phase shunt active power filter to mitigate sensitive power quality issues in IoT devices

The emergence of Internet of Things (IoT) offers numerous functions, such as intelligent sensor integration, remote sensing, and high-speed data transmission, which have found widespread applications in the smart industry and commercial applications. The associative nonlinear effects of a variety of undesirable power quality concerns were resolved by using harmonic mitigation in nonlinear loads and high-performance converters were built on power electronics in conventional systems. Among other performance objectives, total harmonic (THD) distortion analysis and higher order harmonics mitigation is given main concern in smart electronics equipment. This paper proposes an approach to minimize higher-order harmonics due to nonlinear load disturbances in smart IoT devices using the Takagi–Sugeno (TS) Neuro Fuzzy (TS-ANFIS) supervised shunt APF. The proposed work elicits the novel adaptive harmonic mitigation technique in hybrid IoT embedded systems to protect from malfunctioning and to deal with the uncertainty of harmonic signal stimuli in sensitive sensors-based IoT systems. Hysteresis current control is used for the ignition of reference signal under uncertainty of harmonic stimuli. The single phase shunt APF is used to mitigate higher-order harmonics from supply mains, while the implementation of TS-ANFIS supervises the controller action to generate a trigger signal for adequate single phase APF gate excitation. The higher order harmonic current data set is used for error deviation for training neural networks and adaptive control. The estimated adoption of the neuron's empirical weight reduces the total THD to a significant reduction rate of 72.8 % to 0.78 %. The control mechanism is feasible for a range of smart IoT systems to adhere to the standard of 519 (IEEE).

Harmonics mitigation technique for asymmetrical multilevel inverter fed by photovoltaic sources

A multilevel inverter is an electrical device that converts a DC voltage into a higher AC voltage by generating a stepped waveform with several voltage levels. Unlike traditional inverters that produce a square wave or a pulse-width modulated (PWM) waveform with only two voltage levels, multilevel inverters can generate waveforms with three or more levels, resulting in reduced harmonic distortion, improved efficiency, and decreased electromagnetic interference. The design and control of multilevel inverters are active research areas that aim to enhance their performance, reliability, and scalability. In this research, a 31-level asymmetric cascaded multilevel inverter is suggested. The proposed multilevel inverter (MLI) system employs four photovoltaic cells as dc sources with structure of (1:2:4:8) Vdc. The system is modeled by MATLAB/Simulink and total harmonic distortion (THD) values of the output voltage and current are 1.106% for resistive load, and 1.35% and 0.403% for inductive load. These outcomes demonstrate the recommended circuit's efficacy and demonstrate its suitability for medium- and high-power applications.

Unified Switching Frequency Minimized Harmonic Mitigation Technique for Asymmetric Cascaded H-Bridge Converters

Unified Switching Frequency Minimized Harmonic Mitigation Technique for Asymmetric Cascaded H-Bridge Converters

Study of Harmonic Minimization in Pulp and Paper Mill using Hybrid Active Filter -A Case Study

Increased power electronics-based nonlinear loads have harmed distribution system power quality. Variable speed drives, switched-mode power supply, and DC drives impair power quality and affect customers and utilities. Many variable-speed drives in the paper mill cause harmonic distortion, a power quality issue. This study investigates the impact of nonlinear electric drives on supply current distortion in Padmavati Pulp and Paper Mill, Ambarnath, Thane, India. Harmonic analysis is done at PCC, that is, at the secondary side of the transformer, with the help of a power quality analyzer fluke-434. Based on detailed analysis, a suitable harmonic reduction method is identified. passive filters, are the simplest solution for lowering harmonic currents but it has shortcomings like bulk size and cause resonance. In recent years active filter has been applied as an effective solution for harmonic reduction. This study suggests a hybrid filter as an economical solution to take advantage of a passive and active harmonic filter. This work present design and simulation of cascade H- bridge multilevel inverter-based hybrid filter for medium and high-power distribution system. The system for the case study is developed in MATLAB Simulink platform with suitable harmonic mitigation techniques and performance is evaluated in terms of total Harmonic Distortion Index (THDi).

Simulation of grid/standalone solar energy supplied reduced switch converter with optimal fuzzy logic controller using golden BallAlgorithm

This article presents the utilization of a shunt active power filter (SHAPF) in combination with an Energy Storage System (ESS) and a Solar Energy System (SES). Voltage source converters (VSC) are connected in parallel to a direct current (DC) bus. The membership function (MSF) of fuzzy logic controller (FLC) for the shunt control system is optimally adjusted using the golden balloptimization algorithm (GBOA). The present effort aims to achieve the following primary objectives: 1) Quick implementation to stabilize the voltage of the DC Link capacitor (DCLCV); 2) Mitigation of harmonics and improvement of power factor (PF); 3) Satisfactory performance under load as well as solar power varying conditions. The effectiveness of the optimally designed controller is evaluated by studying four test scenarios with grid and standalone conditions. The results are then compared to the existing sliding mode (SMC) and fuzzy logic controllers (FLC).

Harmonic mitigation using optimal active power filter for the improvement of power quality for a electric vehicle changing station

The idea of electric vehicles (EVs) is relatively new in the transportation industry. EVs are becoming increasingly popular due to many advantages. Apart from various advantages, some drawbacks of these vehicles are also a concern. One of the concerns for these vehicles is the substantial power requirement to charge the batteries. During charging, EVs deteriorate the power quality by injecting harmonic current into the system. As poor power quality is undesirable, the mitigation of this harmonic current is essential. Therefore, in this study, an optimal design of a shunt active power filter (SAPF) based EV charging system is suggested. The optimal design of the SAPF ensures that the DC-link voltage is efficiently regulated. To test the performance of the suggested scheme, a simulation system is developed and tested in MATLAB Simulink. The results show that the developed optimal control can efficiently regulate the DC-link voltage. The results, pre and post-compensation, show that the total harmonic distortion in the system is reduced to 4.33 % from 26.72 % using the suggested approach. This is even better by 12.93%, 7.39%, 14.32% and 20.32% in comparison to particle swarm optimization, whale optimization algorithms, bee colony optimization and ant colony optimization used for comparison.

Harmonic Mitigation for Enhancing Grid-Integrated Photo voltaic System Power Quality: A Review

With the growing integration of renewable energy sources, such solar energy systems into electrical grids, power quality issues emerge from possible harmonic distortions. This study analyzes the effectiveness of grid-integrated photovoltaic systems and discusses harmonic mitigation to improve electricity quality. Power quality can be negatively impacted by harmonic distortion due to voltage swings, higher losses, and interference with delicate equipment. As a result, efficient and dependable PV system functioning inside the grid depends on the implementation of effective mitigation techniques. We examine a range of mitigation strategies, such as hybrid solutions, active filters, and passive filters, each with unique benefits and drawbacks in terms of expense, intricacy, and efficiency. The effects of integrating PV systems on grid stability, voltage regulation, and frequency management are also covered in the article, emphasizing the significance of thorough performance analysis. The effectiveness of various harmonic mitigation techniques is assessed by modeling studies and experimental validation, taking into account variables including system efficiency, dependability, and compliance with international power quality standards. The study also looks at how grid circumstances, PV system layout, and size affect harmonic generation and mitigation needs. The research yields valuable insights that aid in the formulation of strategies aimed at improving power quality and maximizing grid-integrated photovoltaic systems' performance under various operating situations. Keywords: Renewable Energy sources, Shunt Active Power Filter, harmonics, fuzzy logic controller, PID controller.

Soft Computing Technique for Harmonic Mitigation of Enhancing Grid-Integrated Photovoltaic (PV) System Power Quality

This abstract explores the use of soft computing techniques for harmonic mitigation in renewable energy integration, particularly for photovoltaic (PV) systems in power grids. Traditional methods often fail to effectively mitigate harmonics, leading to system performance compromise and grid instability. Soft computing's adaptability and ability to handle complex systems offer promising solutions. The study explores the use of soft computing techniques like artificial neural networks, fuzzy logic, and genetic algorithms to mitigate harmonics in PV systems. ANNs learn complex patterns, fuzzy logic handles uncertain data, and genetic algorithms optimize mitigation strategies for varying grid conditions and system dynamics. The study demonstrates the effectiveness of soft computing-based harmonic mitigation techniques in improving power quality indices like total harmonic distortion and voltage stability. It emphasizes the importance of integrating advanced computational approaches in PV systems for seamless grid integration and promoting sustainable renewable energy integration. Key Word: Renewable Energy sources, PV systems, harmonics, fuzzy logic controller, ANNs

Power System Integration of Electric Vehicles: A Review on Impacts and Contributions to the Smart Grid

In recent years, electric vehicles (EVs) have become increasingly popular, bringing about fundamental shifts in transportation to reduce greenhouse effects and accelerate progress toward decarbonization. The role of EVs has also experienced a paradigm shift for future energy networks as an active player in the form of vehicle-to-grid, grid-to-vehicle, and vehicle-to-vehicle technologies. EVs spend a significant part of the day parked and have a remarkable potential to contribute to energy sustainability as backup power units. In this way, EVs can be connected to the grid as stationary power units, providing a range of services to the power grid to increase its reliability and resilience. The available systems show that EVs can be used as alternative energy sources for various network systems like smart grids, microgrids, and virtual power plants besides transportation. While the grid–EV connection offers various contributions, it also has some limitations and effects. In this context, the current study highlights the power system impacts and key contributions of EVs connected to smart grids. Regarding the power system impacts in case of EV integration into smart grids, the challenges and difficulties are categorized under the power system stability, voltage/current distortions, load profile, and power losses. Voltage/current distortions like sags, unbalances, harmonics, and supraharmonics are also detailed in the study. Subsequently, the key contributions to the smart grid in terms of energy management, grid-quality support, grid balancing, and socio-economic impacts are explained. In the energy management part, issues such as power flow, load balancing, and renewable energy integration are elaborated. Then, the fault ride-through capability, reactive power compensation, harmonic mitigation, and grid loss reduction are presented to provide information on power quality enhancement. Lastly, the socio-economic impacts in terms of employment, net billing fees, integration with renewable energy sources, and environmental effects are elucidated in the present study.

Design and Implementation of Single-Phase Grid-Connected Low-Voltage Battery Inverter for Residential Applications

Integrating residential energy storage and solar photovoltaic power generation into low-voltage distribution networks is a pathway to energy self-sufficiency. This paper elaborates on designing and implementing a 3 kW single-phase grid-connected battery inverter to integrate a 51.2-V lithium iron phosphate battery pack with a 220 V 50 Hz grid. The prototyped inverter consists of an LCL-filtered voltage source converter (VSC) and a dual active bridge (DAB) DC-DC converter, both operated at a switching frequency of 20 kHz. The VSC adopted a fast DC bus voltage control strategy with a unified current harmonic mitigation. Meanwhile, the DAB DC-DC converter employed a proportional-integral regulator to control the average battery current with a dynamic DC offset mitigation of the medium-frequency transformer’s currents embedded in the single-phase shift modulation scheme. The control schemes of the two converters were implemented on a 32-bit TMS320F280049C microcontroller in the same interrupt service routine. This work presents a synchronization technique between the switching signal generation of the two converters and the sampling of analog signals for the control system. The prototyped inverter had an efficiency better than 90% and a total harmonic distortion in the grid current smaller than 1.5% at the battery power of ±1.5 kW.

Analysis of the performance of a 25-level inverter with a minimum number of switches and reduced harmonics for an environment solar energy

A multilevel inverter is a type of electrical equipment that converts a DC voltage to a higher AC value by creating a stepped waveform using several voltage levels. Multilevel inverters may create waveforms with three or more voltage levels, although regular inverters cannot. This separation results in lower harmonic distortion, decreased electromagnetic interference, and higher efficiency. An innovative MLI design that makes use of fewer switches and PV sources solves this problem. The Perturbation and Observation (P&O) approach is used to derive the Maximum Power Point Tracking (MPPT) from these PVs. The MC-SPWM technique was used in the design, simulation, and construction of single-phase and three-phase multilevel inverters with inverter levels ranging from three to twenty-five. The technique's cornerstones are phase disposition (PD-PWM) and power quality improvement. The main goal of the paper objectively analyzing the issue of power-system harmonics, providing information on causes, effects, and useful harmonic mitigation strategy.

Controlled random initialization of search vectors for application of gravitational search algorithm to selective harmonic elimination PWM

The prime objective of SHE PWM is to eliminate selected lower order harmonic by solving a set of non-linear transcendental equation while maintaining the fundamental component at a desired satisfactory value. In order to solve these non-linear equations different metaheuristic optimization techniques has been used in recent past. Due to faster convergence rate increased precision and higher probability to calculus based mathematical approximation techniques. In this manuscript an improved initialized Gravitational search algorithm has been proposed for a uni-polar 3-phase inverter. The algorithm is improved upon through a controlled random initialization of search agent, specifically for the purpose of solving the set of non-linear transcendental equation in SHEPWM for 3- switching angles. The simulation of the gravitational search algorithm and the proposed improved initialized GSA has been performed in MATLAB software and comparison of different performance parameter like Harmonic distortion, convergence rate etc. has been studied. The simulation results proves that a considerable improvement has been achieved by applying improved initialized GSA algorithm in terms of harmonic mitigation, convergence rate and accuracy in finding out the appropriate switching angles. Finally, the results obtained in simulation are verified through an appropriate experimental setup.

Enhancing Power Quality with PDO-FOPID Controller in Unified Power Quality Conditioner for Grid-Connected Hybrid Renewables

Addressing the pressing research problem of power fluctuations and grid harmonics in the integration of renewable energy, our proposed control strategy utilizes the Prairie Dog Optimization Fractional Order Proportional Integral Derivative (PDO-FOPID) controller within a Unified Power Quality Conditioner (UPQC) system. This innovative approach is tailored to mitigate harmonics and meet load requirements in grid-connected hybrid renewables. The UPQC system is instrumental in regulating coupling point voltage, countering voltage and current harmonics to enhance overall power quality. The PDO-FOPID controller dynamically adapts control parameters to system dynamics and load changes, ensuring a stable power supply despite the variability of renewable sources. Simulations in MATLAB/ Simulink confirm its superiority over traditional control strategies, such as PI, sliding mode, and fuzzy control, in harmonics mitigation, load fulfilment, and power stability. By effectively addressing these challenges, our proposed solution not only contributes to resolving a critical research problem but also advances the seamless integration of Hybrid Renewable Energy Sources (HRES) into power systems, thereby enhancing overall grid performance and the efficacy of renewable energy integration.

Pelican-FOPID Based DSTATCOM for real-time load compensation and harmonics mitigation in three-phase distribution system

Power quality (PQ) explores the issues resulting from current and voltage deviations. Non-sinusoidal currents were drawn from the electric grid by the nonlinear loads. These non-sinusoidal currents contain harmonics and reactive power that lower the system's overall power quality. Distribution Static Compensator (DSTATCOM) emerged as a promising compensator to provide solution for all PQ issues. Yet the controlling strategy of this compensator was still complex to design. Here, an optimization-based Fractional Order Proportional Integral Derivative (FOPID) was introduced to manage the DSTATCOM process to improve PQ in a standard bus system. The optimal problem of FOPID controller was solved through the use of novel optimization approach. The DSTATCOM with FOPID was linked to the weak bus system. The pulse-signal of DSTATCOM was done using the optimal controller, which analyzes the error value of reference voltage and bus voltage to generate-pulses. The proposed model was designed, and the performance was analyzed under two cases, like IEEE 33 bus system and IEEE 13 bus system. The proposed optimal controller-based DSTATCOM performance was validated under various conditions such as interruption, swell, harmonics and sag. The optimal controller offered Total Harmonic Distortion (THD) value at sag, swell, and interruption period was 0.46%, 1.36% and 0.46% in IEEE 13 bus system, and 1.79%, 2.10% and 2.67% THD in IEEE 33 bus system. Moreover, the issues mitigation performance was compared to another present approach. The validated outcome demonstrates the proposed model provides a good mitigation performance in all PQ issues conditions, so it was well fit for real-time implementation.

Analysis and Mitigation of Harmonics for a Wastewater Treatment Plant Electrical System

Power quality has become a pressing issue that demands solutions as power electronic equipment has been increasingly used in industrial sectors. One critical problem is how to mitigate harmful harmonics generated by the power electronic equipment. This study investigates harmonic distortion issues in a wastewater treatment plant to verify compliance with IEEE standard 519 using simulation software ETAP and realistic data from the plant. Harmonic quantification shows that the plant harmonic situation violates IEEE Standard 519 where harmonic levels exceed its voltage and current limits. Different methods were used to mitigate the harmonic situation where the core is using passive harmonic filters. It is found that the biggest contributor to the harmonic distortion is the system variable frequency drives. Using high-pulse variable frequency drives, such as 18-pulse, is proven to be beneficial for harmonic reduction. Further, installing passive harmonic filters in appropriate locations helps lower voltage and current harmonics to meet IEEE Std. 519 limits. However, adding a passive harmonic filter higher up the power distribution or adding passive filters to the feeder buses is not effective in lowering the Total Harmonic Distortion (THD) of the system. This would have the drawback of increasing the rating of the system bus voltages. Other findings include a lack of medium voltage passive filters on the market and high costs. The study contributes some insight understanding, experience, and methods for engineers when developing solutions for controlling harmonics in similar plants or industrial applications.

Self-Measurement of the Admittance Matrix of AC–DC Power Converter by Internal Harmonic Injection

Frequency-domain impedance or admittance model is widely applied to analyze harmonic stability of power electronic converters. Conventionally, the converter impedance is modeled holistically, without exhibiting the sole effect of different control and phase-locked loop (PLL). Besides, harmonic voltage or current injection external to the converter is usually adopted, which involves dedicated equipment and introduces unexpected inner impedance. In this paper, the response of voltage perturbation upon AC-DC power converter along various voltage signal flow paths is analyzed, based on superposition principle. Each part of admittance and its effect on stability can therefore be quantified explicitly. By injecting harmonic perturbation through the identified paths within the converter controller, each part of admittances, with and without the concerned control or PLL blocks, are measured and summed to be the total admittance. Harmonic voltage mitigation control implemented on a grid-forming converter creates an ideal grid with constant voltage and nearly zero inner impedance at the injected harmonic frequency. The proposed admittance analysis and measurement is successfully applied to power converter with different PLL, voltage feedforward, output power control, DC voltage control and grid-forming cascaded control. Effectiveness of the analysis and the proposed admittance measurement approach are validated by comprehensive simulation and hardware test.

Comparison of Harmonics Mitigation Techniques for Grid-Connected PV System and Introduction of a Concept of Hybrid Filter

Comparison of Harmonics Mitigation Techniques for Grid-Connected PV System and Introduction of a Concept of Hybrid Filter

Fuzzy Logic Application of Steady-state Harmonic Distortion Limits for the Time-varying Harmonics

Harmonic distortion limits recommended by most international standards are designed for the steady-state harmonics, which are typically calculated for planning purpose. A problem can occur, however, when the limits are applied to actual time-varying harmonics. This paper proposes a new fuzzy logic application to apply modified steady-state harmonic limits using total demand distortion, which is recommended in the IEEE standard 519-1992, to the actual measured harmonic distortions which varies with time. Fuzzy logic application can provide simple and easy implementation and reflect experts’ knowledge. The result of fuzzy logic application indicates how close the current waveform is to a pure sinusoidal wave shape and also reveals whether this current harmonic distortion is within or outside the allowable limits. It is expected that this application can contribute for future developments of harmonics monitoring, evaluation, and mitigation strategies in the actual operating status of power system.