Power Quality Impact Research Articles

Enhancing grid resiliency in distributed energy systems through a comprehensive review and comparative analysis of islanding detection methods

Reduction of fossil fuel usage, clean energy supply, and dependability are all major benefits of integrating distributed energy resources (DER) with electrical utility grid (UG). Nevertheless, there are difficulties with this integration, most notably accidental islanding that puts worker and equipment safety at risk. Islanding detection methods (IDMs) play a critical role in resolving this problem. All IDMs are thoroughly evaluated in this work, which divides them into two categories: local approaches that rely on distributed generation (DG) side monitoring and remote approaches that make use of communication infrastructure. The study offers a comparative evaluation to help choose the most efficient and applicable IDM, supporting well-informed decision-making for the safe and dependable operation of distributed energy systems within electrical distribution networks. IDMs are evaluated based on NDZ outcomes, detection duration, power quality impact, multi-DG operation, suitability, X/R ratio reliance, and efficient functioning.

Benders Decomposition-based Coordinated Optimization Method for Medium and Low Voltage Distribution Network with Photovoltaics Access

aims: From the perspective of improving the economic benefit of the distribution network and ensuring the safe operation of the distribution network, the medium and low voltage optimization model with the goal of reducing the operation cost is established. background: Double carbon background and new energy power system policy, a large number of distributed photovoltaic access distribution network caused a great influence, not only on the low voltage distribution network user side power quality impact, photovoltaic full hair also can happen when tide back phenomenon, for the stable operation of the medium voltage distribution network and scheduling, therefore, this paper puts forward a scheduling of the voltage distribution network and low voltage distribution network optimization method, to solve the problems of large-scale distributed photovoltaic access. objective: Reducing operating costs and ensuring the stable and safe operation of the distributed network. method: The optimization problem of medium and low voltage distribution network is decomposed into the main optimization problems of medium voltage distribution network and the sub-problems of optimizing the low-voltage distribution network. An optimal solution is obtained by coordinating the boundary coupling variables between the two problems and solving them iteratively. Finally, the effectiveness of the coordination algorithm is verified by simulating the medium and low voltage distribution network. result: A coordinated optimization method for medium and low voltage distribution network with photovoltaics access. conclusion: It reduces the operation cost, ensures the stable and safe operation of the power grid, thus improving the economic benefits. other: None

Performance and measurement of power quality due to harmonics from street lighting networks

The municipality government of San Miguel de Tucumán city in Argentina is interested in applying energy saving policies to street lighting facilities. In this frame, devices like astronomical programmable clocks and electronic control gear (ballast) will be used to replace photocells and inductive control gear. Also luminaries in use could be replaced by more efficient ones. A technical-economical evaluation was necessary and the technical aspect was request to the Lighting Department of Tucumán University. The performance of the devices and the power quality impact in the lighting networks evaluation was also necessary to evaluate. The study carried out involved outdoor and laboratory test. During 1,5 month six lighting networks with 273 semi-cutoff luminaires were tested. Network selected belong to residential areas which represent more than 60% of total city lighting facilities (26.000 luminaires). In addition laboratory test were conducted with a sample of inductive (in use) and electronic control gear, for high pressure sodium discharge lamps (HPS) 150W. Performance varying voltage input for aged was analyze. Some results from tests points out that: • The use of programmable astronomical clocks instead of photocell produces 11% of energy saving because of actual time on and off schedule set. • Electronic control gear instead of inductive control gear produces 28% energy saving. • Luminaire replacement of current HPS 150W by HPS 100W with Electronic control gear and photocell control produces 43% in energy saving. Outdoor test results from measurement of electrical input parameters and harmonics of existing inductive control gear in street lighting, indicate that: while THD V voltage is about 2,8%, THD A current can be reduced from 38% to 6,5% even when electronic control gear is set to the lower output power step (70% of power output and 60% of initial average illuminance value). The results obtained will be used as arguments for the widespread replacement in the city which would involve considerable investment and a new experience in the region.

Power Quality impact of a small wind energy conversion system connected to the LV grid

This research work is devoted to the study of the Power Quality (PQ) impact of small wind energy conversion systems (SWECS) connected to the low voltage grid. A common coupling point (CCP) has been monitored using a PQ meter that fulfils the standard IEC 61000-4-30 class A. The PQ survey has been conducted with and without the SWECS and the results were compared with the limits defined by the standard EN 50160

Power Quality Impact of Wind Farms on Domestic and Industrial Facilities.

The objective of this paper is to evaluate the impact of a nearby Wind Farm on Power Quality at local domestic and industrial facilities. Adequate, specialized measuring equipment made it possible to measure several quantities and assess the main Power Quality parameters with special incidence on Flicker and Harmonics levels.

Power Quality Impacts of Grid-Tied PV Inverters on Low Voltage Distribution Networks a Smart OpenDSS Model to Find Power Quality Threshold Limits

As a renewable initiative, risen attention can be seen in solar photovoltaic (PV) installations in the world. Since tropical countries and even many other countries during summer experience higher irradiance levels, there is great potential for PV generation in solar panels. However, power quality can be impacted when the number of PV modules is increased in a network due to the emergence of harmonics, unbalanced voltages, voltage flicker, neutral voltage variations, etc. Therefore, it is essential to empirically analyse power quality parameters, i.e., total harmonic distortion (THD), voltage unbalance, etc., and find threshold margins of PV capacities in a network. Based on a case study conducted in Negombo, Sri Lanka, this work determines power quality impacts with reference to the number of PV interconnections in a distributed network. For the task, a low-voltage distribution network was chosen which was fed by a 250kVA, 11/0.4kV transformer with domestic loads and grid-tied PV inverters. A simulation model was developed in Open Distribution System Simulator (OpenDSS) with time-varying load patterns and PV generation. Consequently, a smart efficient method was introduced to model domestic loads with unique time-varying demand patterns. A determination criterion was established to derive snapshot load flow instants using time-varying load flow results to analyse voltage profiles along distribution feeders. Then, the model was enhanced to quantify the power quality parameters such as individual harmonic content, THD of voltage as well as current and neutral voltage variation. The results reveal that node voltage has improved with PV interception without violating the upper limit. The THD of voltage and current have slightly increased with the addition of PV inverters.

Power quality impact on light intensity and flicker sensitivity of LED lamps

Power quality impact on light intensity and flicker sensitivity of LED lamps

Active Compensation-Based Harmonic Reduction Technique to Mitigate Power Quality Impacts of EV Charging Systems

This article presents a novel active compensation-based harmonic reduction (ACHR) technique in order to mitigate the existing third harmonic component in the input current of the power factor corrector (PFC) circuit in electric vehicle (EV) charging systems. Traditional PFC control scheme includes an outer voltage loop to control the output dc voltage and an inner current loop to ensure that the grid current is sinusoidal. The work shows how third and other high-order harmonic components are created, while the signal is transmitting through the voltage control loop, and then, an analytical model is developed to calculate the dominant third harmonic magnitude according to the circuit specifications and control parameters. The ACHR approach takes advantage of multilevel filter design to prevent the presence of high-order odd harmonics in addition to mitigating the existing third harmonic component created by the voltage control loop before it is passed through the current control loop. ACHR is designed optimally, and its performance is analyzed in detail to have a robust and stable closed-loop system while keeping the characteristics of fundamental harmonic. A totem-pole boost PFC proof-of-concept is built to verify the proposed ACHR technique. The results show that the third harmonic magnitude is reduced from 244 mA in conventional control scheme to 130 mA in the proposed ACHR technique. Moreover, total harmonic distortion (THD) in input current is decreased from 4.88% to 4.03%.

Study on the Power Quality of LED Street Luminaires

The paper analyses the power-quality effects of connecting LED luminaires to street lighting installations. The power quality impact of LED luminaires and the implementation of smart control systems are discussed. Several power-quality measurements have been performed to determine the effect of connecting multiple LED luminaires to the electrical power network. Three LED street lighting systems were selected, each equipped only with LED luminaires of different power ratings and numbers, produced by different manufacturers. The measurements were performed at the lighting connection box, and the results are presented and discussed for each case.

A review on power quality issues in electric vehicle interfaced distribution system and mitigation techniques

Electric vehicles (EV) penetration in the distribution systems is evident and intended to grow day by day. Power quality issues pop up in the distribution system with an increase in EV penetration. Distribution networks need to consider the power quality issues developed due to the penetration of EVs for planning and designing the system. The power quality issues, including voltage imbalance, total harmonic distortion, distribution transformer failure, and related issues, are anticipated due to EV penetration in distribution systems. Detailed review of power quality issues and mitigation techniques are detailed in this paper. Discussion on the effect of these power quality issues on the distribution systems and corresponding mitigation measures are detailed. Power quality impact mitigation techniques have been discussed recently, which exploits the bidirectional power flow of vehicle to grid vehicle to grid (V2G) and grid to vehicle grid-to-vehicle (G2V). Methods and methodologies that mitigate power quality problems in the EV penetrated distribution system is discussed. Bidirectional power flow during EV charging and discharging and power quality issues in this topology is detailed in this review paper. A discussion on future trends and different possible future research paradigms is discussed as the review's conclusion.

How to choose the best electric network for a large depot of electric buses?

Electric buses infrastructures will become more and more common in regards to the requirements of environmental regulation both at European and national levels. While an AC centralized architecture is the natural choice for a depot with a small number of buses, the answer is less clear for a large depot with hundreds of electric buses. In this paper, we present the methodology developed by EDF R&D and the results of a study carried out for a depot of 200 electric buses where we compare different electric distribution architectures and the equipment making up these infrastructures. In particular, we apply eight technic and economic criteria to assess each architecture: safety, reliability, availability, power quality, evolutionary perspective, costs, deadlines, and environmental impact. Software simulations greatly support this work. We also discuss several points which will be explored in more details in the future, such as resonance risks, cost of water-cooling for power electronic components, as well as decision tools during the design stage.

Probabilistic assessment of the impact of electric vehicles and nonlinear loads on power quality in residential networks

This paper presents a probabilistic methodology to assess the power quality impact (harmonics and voltage unbalance levels) in low voltage residential networks with increased simultaneous integration of nonlinear loads and electric vehicles. The uncertain behavior of these loads is considered in the model by applying a probabilistic approach that accounts for their stochastic allocation and performance. In particular, different electric vehicle charging locations and modes of charge are assumed for the analysis of the electric car impact and weekly demand profiles are considered for the nonlinear loads. A Monte Carlo simulation is performed in order to obtain a probabilistic assessment of power quality with penetration levels of disturbing loads estimated for year 2030 for different penetration levels of electric vehicles in the system and including the interaction with photovoltaic generation. The methodology proposed is applied to the IEEE European Low Voltage network and to a larger 471-buses residential network and results are compared to EN50160 standard limits as the reference framework for low voltage power quality indices.

New energy grid-connected power quality management system based on internet of things

As a clean and renewable energy source, solar energy has the advantages of inexhaustible, pure and pollution-free. Photovoltaic power generation is different from traditional thermal power generation in that it is more susceptible to external environmental factors. In addition, there are a large number of power electronic devices in the entire system. These various factors will bring a significant shock to the grid power quality after grid connection. The research of grid-connected power quality system is becoming more and more important. A series of researches are carried out around a complete three-phase photovoltaic grid-connected system, which are modeled separately, connected to the distribution network for simulation analysis, and analyzed the power quality impact on the distribution network. Based on the traditional disturbance observation method, this paper proposes a new MPPT algorithm that combines the constant-voltage tracking method with the three-point comparison method (an algorithm derived from the traditional disturbance observation method). This complete three-phase photovoltaic grid-connected system was connected to an IEEE 14-node distribution network, and the impact of grid-connected capacity and grid location on the power quality of different nodes in the distribution network was analyzed. An improved power management scheme is proposed. Finally, the paper analyzes the improvement of power quality by connecting a group of hybrid reactive power compensation device which is composed of static reactive power compensator and shunt capacitor. The results show that the voltage deviation is reduced and the harmonic content is reduced. It can be considered that this measure has achieved the purpose of power quality control to a certain extent.

Case analysis of power quality impact assessment and governance of electrified railway based on ETAP software

As the traction load of electrified railway belongs to high-power nonlinear single-phase load, it will bring power quality problems such as harmonics and three-phase unbalance to the power system after being connected to the power grid, which is not conducive to the safety and economic operation of the public power grid. Therefore, it is necessary to evaluate the impact of the electrified railway operation under different conditions on the power quality of the system substation. In this paper, combined with an electrified railway transformation project of the power grid, an ETAP-based simulation model for electrified railway access to the power grid is established, which can quickly assess the power quality impact of the system-side substation caused by the traction load, and provide corresponding treatment measures for the electrified railway connection system program. At the same time, it can provide a basis for the electrified railway connection system scheme and equipment configuration.

Power Quality improvement provide Digital Economy by the Smart Grid

The developing power supply characterises in smart grid networks of the power system with high power quality (PQ) for the digital economy as one of the attributes. Consumers need good power quality to meet the demand. Consumers consider reliable power that is not affected by interruption and clean energy without unstable influence. The focus of this paper is on good power quality for reducing economic impact. As a result of the vital role that sophisticated, intelligent devices accept in today’s economy attention to PQ is beneficial.T he level of the power quality is transmitted power can change from different “standard” to” premium” by consumer demands. Smart grids provide power grade changes and increase the value of variables in the same way. The evaluation of the power transmitted is mostly dependent on the structure of the electricity transmission that provides services for individual consumers. Unique considerations are specified to control the effects on power quality impact. Smart grids increase the power transmission framework and mitigate the effects of poor PQ starting with regenerative components. The promoted control strategy entire filter and necessary element make quick decisions and accurate solutions on every stage of PQ opportunity. Similarly, the grid structure emphasises the reduction of unstable effects of PQ. The smart grid drive section applies the latest research on superconductivity, materials, energy storage, and reliable modern technology to improve power quality.

Wavelet-fuzzy power quality diagnosis system with inference method based on overlap functions: Case study in an AC microgrid

This work proposes a wavelet-fuzzy power quality (PQ) diagnosis method able to evaluate the PQ impact of steady-state (stationary) PQ events in alternating current (AC) microgrids considering the influence of the power level penetration. The proposed method is composed by a wavelet packet-based signal processing to compute the root mean square (RMS) and steady-state PQ indices of measured voltages and currents, providing accurate results even if transient disturbances take place. Thereafter, a cascade-type hierarchical fuzzy system receives the PQ indices and performs the power quality diagnosis to evaluate the impacts of disturbances on electrical system power quality. The proposed method considers subjectivities of several PQ standards simultaneously and applies an adaptive algorithm that allows the evaluation of the PQ diagnosis from the total harmonic distortion of currents considering different levels of power penetration of microgrids. Experimental results obtained from an ac microgrid laboratory setup evaluates the proposed PQ diagnosis method. In addition, the fuzzy system uses a new inference concept based on an extended n-dimensional overlap function.

Power Quality Impact on the Industrial Sector: A Case Study of Bangladesh

Nowadays, industrial sectors are suffering from electrical power crisis due to the shortage of generation capacity, insufficient conservation, and ineffective supervision. In this investigation that have studied the industrial sector’s effects on the power crisis. There are selected 57 industries which have visited and then analyzed the collected data accurately. This research investigates the impact of electrical disturbances caused by severe power outages and analyzed. Two methodologies have been developed and used for this research. One depends on the industrial consumer’s survey, and others depend on mathematical models that are considered on unavoidable recreational estimates. It has found that a large number of industries are suffering from the power crisis that is facing different types of losses, and some industries have taken different back-up procedures to overcome the losses. The mentioned failures, due to the different types of interruptions, cause a massive economic loss in these industries and afterward lower the gross domestic product. The back-up power generator and a captive power plant is an appropriate option to prevail with this problem, but these are costly and have environmental pollution. This research increases the awareness of energy conservation and the implementation of an aggressive program that can direct the industrial sector in reducing this massive destructive influence on the economic system. This article offers new statistics and information that can be used in various kinds of cost–benefit analysis in the Planning and operation of the power system in the Industrial Sector.

Study on Power Quality Impacts of Rural Distribution Network with Large-scale Heat Pumps

With the advance of the “Coal-to-electricity” program in northern China, heat pump unitsare used more and more widely for rural household heating at a high operating efficiency. When large-scale heat pump units are connected to rural distribution networks, the power quality problems should be considered because of the voltage sag, the current surge, and the harmonics caused by the units. The typical feature, the efficiency index, the operation process and the types of the domestic heat pump units are introduced. The starting characteristics of different heat pump units are compared. Impacts on distribution networkswith heat pumpsare discussed,including the additional load forecast method of heat pump units and the power quality problems. The startup current of the fixed-speed heat pump is too large to cause voltage sag. The variable-speed heat pump may inject the harmonic current into distribution system. A rural distribution network are simulatedwith the actual measurement datain order to analyse the voltage sagsduring the starting process of the heat pump units with different permeability of the units. The corresponding simulation results can be used as the reference for the further implementation of the “Coal-to-electricity” program.

Analysis of the power quality impact in power supply system of Urban railway passenger transportation – the city of Ulaanbaatar

The urgency and expediency of additional passenger transportation by urban railway as an extension of the transport infrastructure of megacities has been proved. The fact that the urban railway uses AC 2x25 kV, which is uses to out of the three phases of city’s power supply system negatively impacts. Thus, it creates a significant asymmetry. In this paper, a comparative analysis on the negative sequence component of the voltage unbalance, which occurs in the nodes of connection of traction substations through both a three-phase transformer or a Scott transformer are been carried out. A mathematical method was created for determining the negative sequence voltage unbalance factor is based on the phase coordinates and symmetrical components methods. The results show that the Scott transformer provides a more symmetrical load distribution to the three-phase electric grid, when compared to the three-phase transformer and was verified using a simulated model in the Matlab program. Consequently, the use of a Scott transformer has better symmetrising abilities than a three-phase transformer, which gives it a significant advantage in the traction power systems.

Probabilistic Risk Assessment of Power Quality Variations and Events Under Temporal and Spatial Characteristic of Increased PV Integration in Low-Voltage Distribution Networks

The aim of this paper is to perform a probabilistic risk assessment of power quality variations and events that may arise due to high photovoltaic distributed generation (PVDG) integration in a low-voltage distribution network (LVDN). Due to the spatial and temporal behavior of PV generation and load demand, such an assessment is vital before integrating PVDG at the existing load buses. Two power quality (PQ) variations such as voltage magnitude variation and phase unbalance together with one PQ abnormal event are considered as the PQ impact metrics. These PQ impact metrics are assessed in terms of two PQ indices, namely site and system indices. A Monte Carlo based simulation is applied for the probabilistic risk assessment. From the results, site overvoltage shows a likely impact to observe as the PVDG integration increases. The probability of 20% of customers violating 1.1 p.u. at 100% penetration level is 0.5. Integration of PVDG reduces the voltage unbalance as compared with no or low PVDG penetration. There is a higher probability of observing deep sag at the site as PVDG integration increases. This probabilistic approach can be used as a tool to assess the likely impacts due to PVDG integration against the worst-case scenarios.