Power Quality In Electrical Systems Research Articles

Medium Voltage Drives (MVD) – Design and Configuration of Eighteen-Pulse Phase Shifting Autotransformer Rectifier for Cascaded H-Bridge Motor Driver Application

Efficiency, dependability, and Simplicity make the eighteen-pulse phase shifting autotransformer rectifier (18PSATR) one of the best solutions to enhancement the power quality of electrical systems. The popular structures utilized in the market of 18PASTR were compared to achieve the best, lowest cost, highest quality, and optimized design. The 18PSATR is a competitive selection to reduce system general harmonics and insulate the grid from hormones produced by the cascaded H-bridge motor driver (CHBMD). A deep check of industrial demands and producer goods, the work considers four configurations contributing to harmonics accepted by IEEE-519 requirements. A comparison is done to exhaustive the best 18PSTAR topology with the minimum use of copper, lowest weight, best dimensions, power quality, and best output voltage waveform. All proposed 18PSATRs are tested, simulated, studied, shown, and produced with low rate of power, voltage and current. The output current, output voltage waveform, and total THD simulation results shown using Simulink analysis show considerable assimilation of each structure. The design of Symmetric Delta differential (18PSTAR-SDD) theoretical, and experimental results show the minimum power-losing rate which improved the quality of power and output voltage waveform. Delta differential configuration has an intelligible arrangement, painless assembly, minimum copper use, easy terminal connection, harmonic cancellation, and higher power quality. The THD of 18PSTAR-SDD from simulation results is less than 2.9%. Compared to other structures, the proposed 18PSTAR diagram reduces total cost and production by a considerable margin. Also, test results approved that the output power of DC load equals 85% of the rectifier rate.

Analysis of balanced, unbalanced, sinusoidal and nonsinusoidal three-phase systems through a Python developed tool

This paper proposes a Python tool for the analysis of balanced, unbalanced, sinusoidal and nonsinusoidal three-phase systems based on the IEEE Std. 1459. The proposed tool was developed to be used by electrical engineers and professionals of related careers providing a free access for electrical power calculations that allows validation and power analysis in power systems. The proposed tool is available for use on a GitHub link and only requires voltage and current signals as inputs, making it possible to dispense expensive commercial network analyzers. The tool is made of two interfaces, one for making power calculations of sinusoidal three-phase systems and the other one for making calculations of nonsinusoidal three-phase systems; both interfaces can be accessed through a main menu. The proposed tool facilitates decision-making in electrical system issues, which helps improving the efficiency and power quality of electrical systems.

Techniques to Locate the Origin of Power Quality Disturbances in a Power System: A Review

The complexity in the power system topology, together with the new paradigm in generation and demand, make achieving an adequate level of supply quality a complicated goal for distribution companies. The electrical system power quality is subject to different regulations. On one hand, EN-50160 establishes the characteristics of the voltage supplied by public electricity networks, therefore affecting distribution companies. On the other hand, the EN-61000 series of standards regulates the electromagnetic compatibility of devices connected to the network, therefore affecting the loads. Power companies and device manufacturers are both responsible and affected in the issue of quality of supply. Despite the regulations, there are certain aspects of the supply quality that are not solved. One of the most important is the location of the disturbance’s origin. This paper presents a review of the main techniques to locate the disturbance’s origin in the electric network through two approaches: identification of the disturbance’s cause and the location of the origin.

Knacks of Fractional Order Swarming Intelligence for Parameter Estimation of Harmonics in Electrical Systems

The efficient parameter estimation of harmonics is required to effectively design filters to mitigate their adverse effects on the power quality of electrical systems. In this study, a fractional order swarming optimization technique is proposed for the parameter estimation of harmonics normally present in industrial loads. The proposed fractional order particle swarm optimization (FOPSO) effectively estimates the amplitude and phase parameters corresponding to the first, third, fifth, seventh and eleventh harmonics. The performance of the FOPSO was evaluated for ten fractional orders with noiseless and noisy scenarios. The robustness efficiency of the proposed FOPSO was analyzed by considering different levels of additive white Gaussian noise in the harmonic signal. Monte Carlo simulations confirmed the reliability of the FOPSO for a lower fractional order (λ = 0.1) with a faster convergence rate and no divergent run compared to other fractional orders as well as to standard PSO (λ = 1).

Time-Series PV Hosting Capacity Assessment with Storage Deployment

Europe aims to diversify energy sources and reduce greenhouse gas emissions. On this field, large PV power growth is observed that may cause problems in existing networks. This paper examines the impact of distributed PV systems on voltage quality in a low voltage feeder in terms of the European standard EN 50160. As the standard defines allowable percentage of violation during one week period, time-series analyses are done to assess PV hosting capacity. The simulations are conducted with 10-minute step and comprise variable load profiles based on Gaussian Mixture Model and PV profiles based on a distribution with experimentally obtained parameters. In addition, the outcomes are compared with “snapshot” simulations. Next, it is examined how energy storage utilization affects the hosting capacity. Several deployments of energy storages are presented with different number and capacity. In particular, a greedy algorithm is proposed to determine the sub-optimal energy storage deployment based on the voltage deviation minimization. The simulations show that time-series analyses in comparison with snapshot analyses give completely different results and change the level of PV hosting capacity. Moreover, incorrect energy storage capacity selection and location may cause even deterioration of power quality in electrical systems with high RES penetration.

Optimal Dynamic Harmonic Extraction and Suppression in Power Conditioning Applications

Power quality in electrical systems is a basic requirement that should be guaranteed. Nonetheless, the increase of power-electronics-based applications and other nonlinear loads have induced harmonic distortion degrading the power quality; therefore, effective methods to measure and suppress such distortion need to be developed. The main contributions of this article are the following: the development of a novel fast-converging optimal estimator to determine online the harmonic components of a time-varying signal, which can be used for analysis and control purposes; the usage of the estimator to generate reference signals for an optimal control system in order to suppress the harmonics components; and the experimental validation of the proposed methodology as a feasible solution for industrial applications. The proposal considers practical assumptions such as the signal to be analyzed is corrupted with noise and contains time-varying harmonics (i.e., no steady-state condition is assumed). As an application of the harmonic estimator, the following two experimental tests are carried out: first, the optimal determination of the harmonic components of the current waveform in a nonlinear load, and second, the usage of harmonics information to mitigate them through of an active power filter, which is controlled by using an optimal trajectory tracking control scheme.

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.

A cascade-type hierarchical fuzzy system with additional defuzzification of layers for the automatic power quality diagnosis

In general the power quality diagnosis of low-voltage electrical systems is a difficult issue due to the nuances of different power quality standards around the world and the uncertainties characteristics of the evaluation parameters. In this framework, this paper proposes a new methodology for diagnosing the power quality by means of a cascade-type hierarchical fuzzy system with additional defuzzification of layers (C-HFS-ADL), also proposed in this paper, which is able to evaluate the power quality indices in steady-state (total harmonic distortions, power factor, voltage variation, and unbalance voltage) considering several standards and provides a proper and complete diagnosis of the power quality in electrical systems. In the proposed C-HFS-ADL each output of a subsystem is transferred between inner layers of the hierarchical system and a total power quality diagnosis is obtained taking into account a secondary decision-making process with additional defuzzification in order to have a partial diagnosis for each subsystem of the hierarchy. In addition, an algorithm was implemented considering different inference systems for analyzing the behavior of the C-HFS-ADL on a database (power quality indices) obtained from a real electrical substation for observing its advantages and disadvantages.

Noise insensitive optimal harmonic estimator design with lightning search algorithm

Abstract Electrical harmonics directly affect the power quality of electrical systems. In order to improve power quality of electrical systems, accurate estimation of electrical harmonics is crucial and essential. This paper presents a novel estimator design approach for harmonic estimation problems. The proposed harmonic estimator is based on lightning search algorithm (LSA) that is a powerful metaheuristic optimization method inspired of natural phenomenon of lightning. The performance of designed estimator has been comprehensively analyzed by considering time varying power signals that contain two well-known estimation problems in the literature. In addition, each of these problems are examined for three different levels of noise. Furthermore, performance of the designed estimator is compared with the previously reported estimators. The achieved estimation results for different case studies clearly indicated that the proposed LSA based harmonic estimator provides better estimation results in all experiments than that of our previous method based on modified artificial bee colony (MABC) optimization and other existing methods available in the literature.

A modified ABC algorithm approach for power system harmonic estimation problems

Electrical harmonic is an important issue on power quality of electrical systems. Therefore, estimation of power harmonics are essential to design filters to be utilized in electrical power systems for reducing harmonics and their effects on the electrical power systems. In this study, a power system harmonic estimation solution based on modified artificial bee colony (MABC) algorithm have been proposed. The proposed method in this study is different from other hybrid techniques previously reported ones since estimation processes are mainly focused on decreasing computational complexity and time. In order to provide more accurate and comprehensive estimation results for the proposed method, two different experiments are investigated. Obtained results by the performed experiments showed that the proposed harmonic estimator provides several advantages such as offering very low computational time, more accurate estimation of amplitude and phase values for all conditions and low complexity.

Issues of Power Quality in Electrical Systems

It is not enough to have power supply. The characteristics of supply voltage at all-time are very essential for smooth operation and service-life of equipment. The voltage characteristics determine the quality of the power supply. The degree to which the supply voltage characteristics conform to the acceptable standard is referred to as Power Quality. With ever increasing use of power electronic devices in domestic and commercial settings as well as sensitive equipment in the industries for automated production, the need for maintaining good power quality has become necessary. This paper elucidates on Power Quality as well as issues associated with it. The causes and consequences of power quality problems are discussed. Techniques for mitigating power quality problems are presented.

Single phase shunt active filter with digital control

This paper presents a single-phase shunt active filter designed to minimize problems related to power quality in electrical systems. The power stage of the active filter is based on a two-leg full-bridge inverter, with a single capacitor in the dc side, and a filter inductor in the ac side. The control system is based on the instantaneous power theory in the α-β-0 reference frame (pq-theory), derived to be applied in singlephase systems. In essence, the shunt active filter is designed to drain, from the electric grid, harmonic and reactive components of the load currents, such that the system current will become, basically, a sinusoidal waveform, with low harmonic distortion, and in phase with the system voltage. Simulation results of the shunt active filter operating with three different loads are presented in order to verify its performance.