Power Quality Conditions Research Articles

Development of an IoT smart energy meter with power quality features for a smart grid architecture

Electricity consumption has been intensifying due to population growth, climate change, urbanization, and the growing use of electronic devices, which are increasingly non-linear loads that cause poor power quality conditions. The trend of the Internet of Things has led to the creation of devices that encourage the efficient and effective utilization of electrical power. This in turn facilitates the development of modern power distribution structures such as smart grids. Consequently, this paper presents in detail the design, construction, and validation of a three-phase IoT smart meter intended to form part of the end-user demand side of a smart grid. The compact embedded system, with a manufacturing cost below $80 USD, features a unique electronic design that enables its installation in any load center and employs a straightforward IoT structure that includes WiFi technology for Internet communication. Also, a deployed web application was developed specifically to display the smart meter measurements. Unlike other smart meters, the proposed meter not only provides the amount of active energy consumption, but total and fundamental RMS current and voltage, active, reactive, and apparent power, reactive energy, power factor, and some power quality parameters such as, line frequency, amplitude of 64 current harmonics, and total harmonic distortion. Additionally, this study shows that the prototype achieves an absolute error of less than 1% in all its measurements. Finally, real-life applications of the developed device are demonstrated in residential environments.

Active Energy Meters Tested in Realistic Non-Sinusoidal Conditions Recorded on the Field and Reproduced in Laboratory

Metrological characterisation of static energy meters under realistic low power quality conditions is a basic requirement for proper grid control and fair energy billing. The paper reports about a new proposed methodology, where the meters are tested under conditions directly recorded at installation sites. The waveforms of voltages and currents are sampled using a portable instrument; they are reproduced in laboratory conditions with a phantom power generator, with a bandwidth covering up to the 40th harmonic. The recording site is a photovoltaic energy production facility, having a a nominal power of 50 kW, at the coupling section to the grid. These waveforms were then reproduced in the laboratory, and tested on different models of single- and three-phase commercial static energy meters; the models chosen represent both energy meters used by energy providers at the point of common-coupling, and also meters typically used for in-line monitoring by end users. The quantity of interest is the reading error of the measured energy, when tested with the conditions reproduced from the on-field measurements, in comparison with a reference meter. All tested energy meter models comply with the present international documentary standards, which require tests under low power quality conditions; nevertheless, there are models that show unacceptable errors (up to 25%) in the measurement of active energy when tested with the on-field recorded waveforms. This suggests that the standardised testing waveforms might, in some cases, be not fully representative of the actual conditions encountered in the field.

Power quality stabilization system for grid connected large-scale solar power system

This paper presents solution to power quality issues when integrating a 1.5 MW photovoltaic array (PVA) with a unified power quality conditioner (UPQC) into the power grid. A modified unit vector template control scheme is used to generate a reference load voltage signal, and a synchronous reference frame (SRF) is created using a low-pass filter to control UPQC. Furthermore, the PVA is interfaced with the grid through a common DC link of shunt and series converters. The series converter mitigates power quality problems allied with the grid side, such as 3rd, 5th, and 7th harmonics, voltage sag, and voltage swell, by introducing signals in phase and out of phase voltage, respectively, at the point of common coupling (PCC). The shunt converter mitigates nonlinear load current harmonics and compensates for reactive power using SRF. The suggested methodology is implemented using MATLAB Simulink with both linear and nonlinear loads under different power quality conditions. Total harmonic distortions are maintained below 5% at PCC, as per IEEE-519 standards.

Active power filter module function to improve power quality conditions using GWO and PSO techniques for solar photovoltaic arrays and battery energy storage systems

This study aims to unbalanced power quality (PQ) conditions analysis of solar photovoltaic arrays and battery energy storage system (PV-BESS) integrated active power filter module (APFM). Here, the APFM's role is to mitigate the PQ issues that existed by the nonlinear loads. The standalone PV-APFM design is negligibly reliable approximated to a hybrid PV-BESS system because of its fluctuation and high environmental reliance. Further, here the research challenge is to optimise the APFM controller gain coefficients by the grey wolf optimization (GWO) algorithm and apply this technique to current and voltage harmonic loops (CHL-VHL) to achieve the best answer to enhance the unbalanced PQ conditions. The multi-objective functions (MOFs) to crack the problem include the total harmonic distortion (THD) of current and voltage components. The particle swarm optimization (PSO) approach will be considered a complementary method for validation and comparison with the outcomes obtained from the GWO procedure. Four case studies in imbalance conditions have been considered to confirm the proposed method in MATLAB-Simulink software.

Analysis Of Modern Railway Power Quality Conditions With Inspection Methods To Mitigate Operating System Failures Referring To Regulations And Standard References

Elevated stations or commonly called elevated stations have an electric power system with a main power supply of 20KiloVolt with a nominal voltage of 750volt and a station operating facility voltage of 380volt laying station. This research uses the inspection method by making observations by work instructions and instruction manuals for railway infrastructure maintenance studies. Some were identified as related to power quality issues with progression-appropriate inspections and appropriate instruction manuals. The main objective of this study is to prevent overvoltage interference problems by recommending risk mitigation through investigative and simulation analysis methods using Electric Transient and Analysis Program (ETAP) software that can help evaluate and estimate strategic steps by paying attention to regulations and standard references and detecting losses in operating pattern disturbances due to disruption of power quality conditions caused by overvoltage surges in the station traction substation system by investigation and simulation methods using Electric Transient and Analysis Program (ETAP) software. This overvoltage is carried out in the context of research on maintaining services to the public and preventing system failures by using risk mitigation and investigation and simulation methods using Electric Transient and Analysis Program (ETAP) software that pays attention to environmental, safety, technical, and economic aspects with regulations and standard references. This research is in the form of mitigation analysis and describes the losses that have an impact by looking at a power quality condition and the follow-up provided to prevent overvoltage and components of modern railway electric facilities.

Analisis Kualitas Daya dan Rekomendasi Perbaikan Sistem Kelistrikan di Gedung Perhotelan

Fave Hotel is supplied by 2 PLN transformers, with capacities of 250 kVA and 100 kVA. The supply of electrical energy at Fave Hotel is very important because the possibility of disruption is very large in the process of distributing electrical energy. Load variations at Fave Hotel will also affect the electrical system. One of the disturbances that occur in the electric power system is power quality. The research method used is data observation, monitoring, analysis, and simulation using ETAP software. Based on the results of the analysis of various power quality parameters that were measured, the power quality conditions of the fave hotel were not good. A power quality problem has been identified at Fave Hotel, specifically a voltage imbalance occurs at MDP 2 on weekend is 2.64%. In addition, there is also a current imbalance occurs at MDP 1 and 2 during both weekends and weekdays, with the largest current imbalance occurs at MDP 2 on weekdays is 64.15%. To overcome the problem of voltage imbalance and current imbalance, it is recommended to perform load balancing on the system or install compensating equipment such as a voltage compensator.

Modeling Power Flows and Electromagnetic Fields Induced by Compact Overhead Lines Feeding Traction Substations of Mainline Railroads

The ongoing re-equipment of electric power systems is based on the use of smart grid technologies. Among the key tasks that are solved on this basis are increasing the capacity of power transmission lines, reducing losses, and improving power quality. To address these issues, one can use compact power transmission lines. Such lines are notable for their complex split-phase designs and close together placement of current-conducting parts, so as to keep the distance to a permissible minimum, which is achieved by the use of insulating spacers. This article reports the results of computer-aided simulations performed for a standard railroad power supply system, the traction substations of which were connected to 220 kV networks through compact overhead lines (COHLs). The purpose of the study was to calculate the values of quantitative metrics that measure power quality and energy efficiency as well as electromagnetic safety. Modeling was performed in the three-phase reference frame with the use of techniques and algorithms implemented in the Fazonord software package. We considered a power supply system with 25 kV overhead contact systems. It was assumed that the external network used three different designs of COHLs: with coaxial, linear, and sector-shaped arrangements of conductors. Based on the results obtained, we concluded that (1) when using COHLs, the voltages on bow collectors of electric rolling stock were stabilized and did not exceed permissible limits; (2) losses in the traction network were reduced; and (3) the parameters of power quality and electromagnetic safety conditions in external power supply systems of railroads were improved, if judged in terms of electric and magnetic field strengths. Out of the eight types of COHLs considered, compact lines with the three-segment and concentric arrangement of conductors had the best performance, and the use of COHLs with the vertical arrangement of conductors made it possible to reduce electric field strengths. However, the designs of such transmission lines are quite complex and entail higher construction costs.

Analisis Power Quality Sistem Kelistrikan Pada Apartemen Malang City Point

The use of equipment with a high non-linear load causes a decrease in the quality of power (Power Quality) at Malang CityPoint Apartment. Power quality analysis is an important requirement in the electrical system and needs special attention to save energyand costs. Savings can be achieved by reducing or even eliminating losses resulting from the use of non-linear loads. This thesis aims topresent the results of an analysis of power quality conditions at Malang City Point Apartments. This analysis includes voltage, current,voltage and current imbalance, power factor, current THD and measured voltage. The system is designed using Web - Based PowerQuality Meter (PM 5110) as a measurement tool, then the results are analyzed and compared with existing standards to evaluate powerquality in Malang City Point Apartments. Among the various power quality problems measured, it was found that the main problems ofpower quality in Malang City Point Apartments were the occurrence of overvoltages and current harmonic distortion. So it is necessary todo repairs on this to overcome the overvoltage by reducing the operation of equipment that has a large load and repairing neutralconductors. Furthermore, to reduce the system harmonics, it is designed by designing a single tuned passive filter and simulated using theETAP software version 16.0.0

A meta‐heuristic capacitor placement framework for distribution grids using modal resonance analysis

Shunt capacitors are usually installed in distribution grids for power factor correction. On the other hand, the number of harmonic-producing sources such as wind turbines (WTs), photovoltaic (PV) panels, storage units, and electronic loads is rapidly growing in distribution grids. Since improper placement and sizing of shunt capacitors in harmonic-polluted grids may aggravate power quality conditions and lead to harmonic resonance, special attention should be paid to this optimization problem when harmonics are present. In this paper, a framework based on shuffled frog leaping algorithm (SFLA) is proposed for optimal placement of fixed capacitor banks. Moreover, a resonance index (RI) is proposed for assessment and mitigation of potential harmonic resonance based on resonance mode analysis (RMA). The resonance mitigation method helps in avoiding power quality constraint violations and directs the algorithm toward the feasible solution space. It thus results in a higher efficiency, and the chance of reaching (near) globally optimum solutions increases. The proposed algorithm is particularly useful when detailed data regarding the harmonic injection pattern of nonlinear sources is not available. The proposed framework is implemented on the IEEE 18, 34, and 69-bus test systems, and the results demonstrate its advantages, especially in larger grids.

Battery energy storage performance in microgrids: A scientific mapping perspective

Microgrids integrate various renewable resources, such as photovoltaic and wind energy, and battery energy storage systems. The latter is an important component of a modern energy system, as it allows the seamless integration of renewable energy sources in the grid. The research here presented aimed to develop an integrated review using a systematic and bibliometric approach to evaluate the performance and challenges in applying battery energy storage systems in microgrids. Search protocols based on a literature review were used; this included thematic visualization and performance analysis using the scientific mapping software SciMAT (Science Mapping Analysis Software Tool). The results show that optimization methods in battery energy storage systems are important for this research field. In research works, they are interested in applying methods to reduce costs; this includes considering the state of charge, the degradation rate, and battery life. Developing an optimal battery energy storage system must consider various factors including reliability, battery technology, power quality, frequency variations, and environmental conditions. Economic factors are the most common challenges for developing a battery energy storage system, as researchers have focused on cost–benefit analysis.

A New Hybrid Synchronization PLL Scheme for Interconnecting Renewable Energy Sources to an Abnormal Electric Grid

Today, and especially with the growing interest in distributed renewable energy sources (DRESs), modern electric power systems are becoming more and more complex. In order to increase DRES penetration, grid side converter (GSC) control techniques require appropriate synchronization algorithms that are able to detect the grid voltage status as fast and accurately as possible. The drawbacks of the published synchronization phase-locked loop (PLL) techniques were structured mainly around the slow dynamic responses, the inaccuracy of extracting the fundamental components of the grid voltages when they contain a DC offset, and the worsening of the imbalance rejection ability facing significant frequency changing. This paper proposes a new synchronization PLL technique ensuring efficient and reliable integration of DRESs under normal, abnormal, and harmonically distorted grid conditions. The proposed PLL uses the mixed second- and third-order generalized integrator (MSTOGI) in the prefiltering stage through its adaptability to power quality and numerous grid conditions and its low sensitivity to input DC and inter-harmonics. Moreover, a modified quasi type-1 PLL (MQT1-PLL), which integrates two compensation blocks for phase and amplitude errors, respectively, has been used in the control loop. The discussion of sizing requirements and the effectiveness of the so-called MSTOGI-MQT1-PLL are tested under grid voltage imbalances and distortions and confirmed through simulation results compared to double second-order generalized integrator PLL (DSOGI-PLL), cascaded delayed signal cancellation PLL (CDSC-PLL), and multiple delayed-signal cancellation PLL (MDSC-PLL).

Analisis Power Quality Sistem Kelistrikan Pada Apartemen Malang City Point

Abstract: The use of equipment with a high non-linear load causes a decrease in the quality of power (Power Quality) at Malang City Point Apartment. Power quality analysis is an important requirement in the electrical system and needs special attention to save energy and costs. Savings can be achieved by reducing or even eliminating losses resulting from the use of non-linear loads. This thesis aims to present the results of an analysis of power quality conditions at Malang City Point Apartments. This analysis includes voltage, current, voltage and current imbalance, power factor, current THD and measured voltage. The system is designed using Web - Based Power Quality Meter (PM 5110) as a measurement tool, then the results are analyzed and compared with existing standards to evaluate power quality in Malang City Point Apartments. Among the various power quality problems measured, it was found that the main problems of power quality in Malang City Point Apartments were the occurrence of overvoltages and current harmonic distortion. So it is necessary to do repairs on this to overcome the overvoltage by reducing the operation of equipment that has a large load and repairing neutral conductors. Furthermore, to reduce the system harmonics, it is designed by designing a single tuned passive filter and simulated using the ETAP software version 16.0.0.

Energy Efficiency Evaluation of Distribution Network Considering Power Quality Conditions

There are three-phase imbalance, voltage deviation, frequency fluctuation and other power quality problems in the traditional AC distribution network, which are difficult to meet the demand of power users for high power quality. The AC-DC hybrid distribution network is superior to the AC distribution system in terms of reducing power loss and improving power supply quality. Based on the research status of energy-saving indexes of distribution network, considering the characteristics of AC-DC hybrid distribution network, this paper analyzes the factors that affect the energy efficiency level of AC-DC hybrid distribution system, constructs the evaluation index system, determines the classification evaluation standards of different indexes according to the relevant standards, and puts forward the quantitative evaluation method of the energy efficiency level of AC-DC hybrid distribution network.

Fractional Order Controller for Non-linear Current Control Technique

linear and Non-Linear controller shows their best performance under different power quality conditions. However, under sub transient condition these controller shows sluggish performance. This paper introduces the application of Fractional order [FO] controller in real world power system phenomena. FO-controller based on proportional integral control action was used here for grid interconnection of inverter. Different power quality issues such as Real & Reactive Power exchange between renewable source and grid have been presented here. Matlab Simulink model was developed for a real-world grid connected model in order to check the robustness of the controller. A comparison between the PI controller and FO-PI controller was presented in this paper.

Impact of Power Quality on the Performance of Distribution Transformers: A Fuzzy Logic Approach to Assessing Power Quality

Power Quality (PQ) is a major factor for utilities to consider when meeting customer demands. Poor PQ can damage sensitive equipment and lead to costly repairs, resulting in lost time, corrupt data, and lower productivity. It also increases losses, raises electricity bills, and reduces the life expectancy of electrical equipment. In this article, a fuzzy system is used to determine PQ for various operating conditions and study its effect on the performance of distribution transformers (DTs). Experiments are performed on a three-phase, 15-kVA, 400/400-V DT. The input supply voltage to the DT is intentionally disturbed by means of a motor-alternator-variacs-triacs assembly to obtain different PQ conditions. A fuzzy system is developed with offline and online approaches. This system has five measurable inputs-supply voltage, load current, frequency, harmonics distortion, and winding temperature-and one output variable, PQ. Offline and online experimental results are compared. Results show that the efficiency of a DT decreases with PQ degradation, and the proposed fuzzy system is able to make accurate diagnoses.

A Design of PWM Controlled Calibrator of Non-Sinusoidal Voltage Waveforms

Power quality conditions in electrical power networks have drastically changed in recent years. A number of electrical devices and power generators that are the main sources of disturbances is ever increasing. Thus, the need for calibrators of different electrical equipment that will be able to generate non-sinusoidal voltages and/or currents has proportionally increased. This paper presents a simple, unconventional approach of generating voltage harmonics, which do not rely on digital-to-analog (D/A) boards and power amplifier to amplify low-voltage signals. A fundamental part of the calibrator is the insulated gate bipolar transistor (IGBT) inverter with low-pass LRC filter at its output, which eliminates higher harmonics from the generated voltage. Desired voltage waveform is directly generated at the inverter’s output, thus the power amplifier is omitted from the setup. The modulation technique used for controlling IGBTs is the well-known sine pulse width modulation (PWM). Magnitudes and phase angles of the desired harmonics are regulated to compensate for the phenomena that may have a negative influence on their values: Nonlinearities of the system, temperature variation, voltage drops on parasitic components, etc. Experimental results show great potential of the proposed method for the design of the voltage calibrator for various electrical instruments.

Integrated Photovoltaic Inverters Based on Unified Power Quality Conditioner with Voltage Compensation for Submarine Distribution System

This paper proposes a multi-functional Photovoltaic (PV) inverter based on the Unified Power Quality Conditioner (UPQC) configuration. Power quality improvement is a difficult issue to solve for isolated areas or islands connected to the mainland through long submarine cables. In the proposed system, the line voltage is compensated for by the series inverter while the shunt inverter delivers the PV generating power to the grid. Depending on the technical conditions of power quality and system environment, it has five different operating modes. Especially during poor power quality conditions, the sensitive load is separated from the normal load to provide a different power quality level by using the microgrid conception. In this paper, the control method and the power flow for each mode are described, and the operational performance is verified through a PSiM simulation so that it can be applied to the power quality improvement of weak grid power systems such as in isolated areas or on islands connected to the mainland by long submarine cables.

Grid emulator for small scale distributed energy generation laboratory

This paper presents the design of a grid emulator dedicated to test small scale distributed energy generation. laboratory The proposed emulator aims to test its performances under different power quality conditions considering grid codes and standards. The developed emulator can generate common grid faults and line impedance variations. This last point is an additional feature versus common grid emulators. The paper discusses design and implementation aspects. Emulator performance analysis are investigated under special operating conditions. Simulation results are carried out to illustrate theoretical developments and a set of experimental results are provided to demonstrate the effectiveness of the proposed emulator.

Model for Analysis of Power Quality Index and Determination of Its Causes and Effects

The Power Quality (PQ) gets affected not only because of the load but also because of the source as power electronics devices applications are widely spread in both sides. The renewable energy sources used power electronics converters and the nonlinear loads connected at consumer premises are the main causes of PQ distortions. This hampered PQ supply, when fed to equipments (or loads), affect the performance of them by increasing the energy lose, increasing the electricity bill and reducing their life expectancy. This article proposed a model for the analysis of different PQ events by means of Wavelet Transforms (WT) and Artificial Neural Network (ANN) composition. The different types of PQ events are generated in the laboratory under the source and load distortion conditions. The supply side voltage waveforms under linear load condition and load side current waveforms under normal supply conditions are considered for analysis. These waveforms are processed by WT and the scaling coefficients are determined for various PQ events. These coefficients are used to train ANNs for decision making. The proposed model is developed in MATLAB for offline and online applications. The results obtained by both the methods are compared and found satisfactory. At the end, the losses incurred in the transformer considered for performance, its efficiency and life expectancy are presented for different PQ conditions.

Reduced Rating 30-pulse AC-DC Converter for Power Quality Improvement

This paper presents the design and analysis of a novel polygon connected autotransformer based 30-phase ac-dc converter which supplies Direct Torque Controlled Induction Motor Drives (DTCIMD’s) in order to have better power quality conditions at the point of common coupling. The proposed converter output voltage is accomplished via three paralleled 10- pulse ac-dc converters each of them consisting of 5-phase diode bridge rectifier. An autotransformer is designed to supply the rectifiers. The proposed converter requires only three inter-phase transformers in the dc link that leads to the reduced kilovolt ampere rating, size, weight, and cost of the proposed rectifier. The design procedure of magnetics is in a way such that makes it suitable for retrofit applications where a six-pulse diode bridge rectifier is being utilized. The aforementioned structure improves power quality criteria at ac mains and makes them consistent with the IEEE-519 standard requirements for varying loads. Furthermore, near unity power factor is obtained for a wide range of DTCIMD operation. A comparison is made between 6-pulse and proposed converters from view point of power quality indices. Results show that input current Total Harmonic Distortion (THD) is less than 3% for the proposed topology at variable loads.