Power Quality In Distribution System Research Articles

Performance Analysis of Single Phase AC-AC Voltage Converter for Compensation of Voltage Issues in Power Distribution System

The power quality of the power distribution system is highly concerned with the use of renewable sources, solid-state electronic devices, and power electronic processors. This results in voltage fluctuations, voltage sag, and swell issues. The voltage source converter (dc-to-ac) can resolve these issues but there is a problem with high rating storage devices. The Dual converter (ac- to-dc) will be useful for energy-storing devices but due to complex circuit arrangement and high conversion losses, this converter is not favorable. The direct AC-AC voltage converter is a matter of research due to simple conversion. This paper presents the performance analysis of a single-phase ac-to-ac voltage converter operating in inverting and non-inverting modes with no current commutation problems. The performance analysis of the proposed converter is been done in MATLAB/Simulink 2019b. Keywords-Voltage sag and swell, voltage control, inverting mode, non-inverting mode, power distribution system

Grid connected photovoltaic system impression on power quality of low voltage distribution system

Grid connected photovoltaic system impression on power quality of low voltage distribution system

Harmonic analysis in distributed power system based on IoT and dynamic compressed sensing

Massive distributed clean energy takes power electronic equipment as the grid​ access connector, which brings serious harmonic pollutions. To monitor the power quality in the massive distributed power systems, this paper proposes a real-time harmonic monitoring and analysis framework based on Internet of Things (IoT) and dynamic compressed sensing. In sensing node, the power quality signal is continuously sampled and compressed with sliding time window. In edge node, a homotopy optimization with fundamental filter (HO-FF) algorithm is designed. Along the homotopy path in the solution space, the current compressed data frame is iteratively recovered based on previous recovery result, hence the computational complexity is greatly reduced and the real-time performance of dynamic power quality signal recovery is improved. Besides, a fundamental filtering scheme is adopted to further improve the signal recovery accuracy and to avoid repeated recovery of fundamental component. Tests based on Siemens benchmark 0.4kV microgrid model show that, compared with existing methods, the proposed HO-FF algorithm could offer better harmonic detection accuracy with lower computational complexity.

Novel Optimization-Based FACTS Devices for Improving the Power Quality in Electrical Distribution Systems

Novel Optimization-Based FACTS Devices for Improving the Power Quality in Electrical Distribution Systems

Coordinated planning in improving power quality considering the use of nonlinear load in radial distribution system

<span lang="EN-US">Power quality has an important role in the distribution of electrical energy. The use of non-linear load can generate harmonic spread which can reduce the power quality in the radial distribution system. This research is in form of coordinated planning by combining distributed generation placement, capacitor placement and network reconfiguration to simultaneously minimize active power losses, total harmonic distortion (THD), and voltage deviation as an objective function using the particle swarm optimization method. This optimization technique will be tested on two types of networks in the form 33-bus and 69-bus IEEE Standard Test System to show effectiveness of the proposed method. The use of MATLAB programming shows the result of simulation of increasing power quality achieved for all scenario of proposed method.</span>

Improvement of the Voltage Profile and Loss Reduction in Distribution Network Using Moth Flame Algorithm: Wolaita Sodo, Ethiopia

Voltage stability and line losses are inevitable issues even in modern power systems. There are several techniques that emerged to solve problems in the power system to provide quality and uninterrupted supply to customers. The algorithms used in this paper to determine the appropriate location and size of the Static Var Compensator (SVC) in the Distribution Network (DN) are Moth Flame Optimization (MFO) and Particle Swarm Optimization (PSO). The objective function is defined to minimize voltage deviation and power loss. The burning problem of voltage stability improvement current scenario is because of a rise in electricity demands in all sectors. Paramount duties of power engineers are to keep the system stable and maintain voltage magnitude constant even during peak hours. The results were checked with the aid of MATLAB on Wolaita Sodo radial distribution of 34 bus data networks. The potential use of SVC is key to solve distribution system power quality issues and estimating the advantage of the installation. The results obtained from the test system were compared with PSO results. This comparison was done to know the computational time of proposed techniques. The performance of the MFA based SVC was superior in distribution system and highlighted the importance of device.

Distribution system power quality compensation using a HSeAPF based on SRF and SMC features

The purpose of this paper is to describe the design of a Hybrid Series Active Power Filter (HSeAPF) system to improve the quality of power on three-phase power distribution grids. The system controls are comprise of Pulse Width Modulation (PWM) based on the Synchronous Reference Frame (SRF) theory, and supported by Phase Locked Loop (PLL) for generating the switching pulses to control a Voltage Source Converter (VSC). The DC link voltage is controlled by Non-Linear Sliding Mode Control (SMC) for faster response and to ensure that it is maintained at a constant value. When this voltage is compared with Proportional Integral (PI), then the improvements made can be shown. The function of HSeAPF control is to eliminate voltage fluctuations, voltage swell/sag, and prevent voltage/current harmonics are produced by both non-linear loads and small inverters connected to the distribution network. A digital Phase Locked Loop that generates frequencies and an oscillating phase-locked output signal controls the voltage. The results from the simulation indicate that the HSeAPF can effectively suppress the dynamic and harmonic reactive power compensation system. Also, the distribution network has a low Total Harmonic Distortion (< 5%), demonstrating that the designed system is efficient, which is an essential requirement when it comes to the IEEE-519 and IEC 61,000–3-6 standards.

Improvement of Power Quality in Distribution System using Photovoltaic based DPFC

In Modern Power System power quality is the main issue of the power companies. Improvement of power quality in distribution system using photovoltaic based DPFC is declared in this paper. Flexible AC Transmission System (FACTS) device which is known as distributed power flow controller (DPFC)is used. DPFC is derived from UPFC by eliminating common dc link between series and shunt converter. Unified power flow controller (UPFC) is widely used and control all parameters of the system. The UPFC handle the current and voltage with high rating; therefore, the cost of system is high. Therefore, distributed power flow controller (DPFC) is used due to high control capability, high Reliability &amp; low cost. DPFC also measures the transmission angle, line impedance and bus voltage. In distribution system problems occur like voltage sag/swell, Harmonics etc. Photovoltaic system is used as source for DPFC.

Desing and Analysis of D-STATCOM for Improving Power Quality in Micro Grids

Endüstriyel uygulamalarda kullanılan yüklerin büyük bir kısmı gelişen teknolojiyle birlikte endüktif yüklerden oluşmaktadır. Endüktif yükler, yapıları gereği endüktif reaktif enerji tüketmektedirler. Tüketilen bu reaktif enerji, sistemin kalitesinde ve verimliliğinde düşüşe ve güç faktöründe sorunlara neden olmaktadır. Esnek alternatif akım iletim sistemleri (FACTS), güç sisteminin performansını ve kalitesini arttırmada önemli bir rol oynamaktadır. FACTS sistemiyle donatılmış bir güç sisteminin kontrolü daha hızlı ve kolaydır. Dağıtım Statik Senkron Kompanzatör (D-STATCOM), güç kalitesini arttırmak için kullanılan en yaygın FACTS cihazıdır. Reaktif güç kontrolü için kullanılan D-STATCOM, dağıtım sistemlerinde güç kalitesini arttırmak amacıyla kullanılan şönt bir cihazdır. D-STATCOM şebeke ile reaktif güç alış verişinde bulunarak gerilim dalgalanmalarını önler. Bu çalışmada, güç kalitesi problemlerinin kaynağında yok edilebilmesi için dağıtım hattıyla reaktif güç alışverişi yapan ve gerilim kaynaklı dönüştürücü temeline dayanan D-STATCOM’un modellenmesi MATLAB Simulink kullanılarak yapılmış ve benzetim sonuçları incelenmiştir. Modellenen sistemde, 4 km uzunluğunda bir dağıtım hattı, hat sonunda kompanzasyon için kullanılan D-STATCOM, 16,40 kVA (10kW+13kVAR) ve 22,36 kVA (10kW+20kVAR) gücünde iki ayrı test yükü kullanılmıştır. Bu yüklerin dağıtım hattında meydana getirdiği güç kalitesi problemleri modellenen D-STATCOM aracılığıyla giderilmeye çalışılmıştır. Yapılan benzetime göre, D-STATCOM şebekeye bağlandığında, sistemdeki gerilim dalgalanmasının ve toplam harmonik distorisyonunun (THD) büyük oranda azaldığı doğrulanmıştır. Sonuç olarak, D-STATCOM’un şebekedeki değişken yüklerin neden olduğu gerilim artışını veya çökmesini büyük ölçüde giderdiği, güç kaybını azalttığı ve buna bağlı olarak da gerilim kararlılığını arttırdığı gösterilmiştir.

IMPROVEMENT OF POWER QUALITY ISSUES USING UNIFIED POWER QUALITY CONDITIONER IN DISTRIBUTION SYSTEM

The research work is predominantly focused on to improve the power quality in distribution system using UPQC system connected with grid.Generally the UPQC has 12 switches for improving the power quality, reduce the sag and swell and decrease the harmonic distortion.The unified power quality conditioner has reduced switches and also decreases the harmonic using various controllers. The series and shunt converter connects the dc link capacitor for ripple reduction but in nine switch UPQC device has integrate the series and shunt converter without capacitor.The unified power quality conditioner has presented for reduce the coupling problem by the presence of switching leg. A particle swarm optimization (PSO)-based multi-objective planning algorithm for power compensation of radial distribution system with UPQC consists of a series and a shunt inverter. The UPQC model based on phase angle control was used. In distributed system needs to explain the approaches for standard supply voltage droop and voltage swell. ThePSO-ANNcontroller has most appropriate in dynamic response with a simple configuration and reduces harmonics.

Harmonic Assessment in Jordanian Low-Voltage Electrical Power Grid

With the proliferation of nonlinear loads in the power system, harmonic pollution becomes a serious problem that affects the power quality in both transmission and distribution systems. Understanding and quantifying the harmonics level in electrical power grid are crucial before proposing any successful method for mitigating harmonics problems in the grid. In this paper, the harmonics level in Jordan Low-Voltage Electrical Power Grid (JLVEPG) is investigated. The loads are divided into five categories: : (i) industrial loads, (ii) commercial loads, (iii) hospital loads, (iv) residential loads, and (v) office loads. Assuming each category will inject similar harmonics in the grid, this will make the harmonic assessment in the power system is easier and help proposing harmonic mitigation solutions. A field measurement for the major electrical units (Voltages, currents, and power) in JLVEPG is carried out for different locations in multiple cities. These measurements are followed by data analysis techniques in order to identify the total harmonic distortion (THD) and the most dominant harmonic in each load category.

MODELING AND SIMULATION OF STATCOM FOR POWER QUALITY IMPROVEMENT

In power system, reactive power compensation is one of the important action to maintain better voltage profile, stability and decrease losses. STATCOM is feasible in terms of cost effective in wide range of problem solving capabilities among all Flexible AC Transmission system (FACTS) in both transmission and distribution levels. In this paper the synchronous rotating frame theory algorithm is used since it is easy to implement i.e. the rotating three phase quantities are converted into stationary components. So it requires less number of PI controllers and also calculations on the stationary quantities are easy than to do calculations on instantaneous quantities and the modeling of STATCOM is done. This project focuses on improvement of power quality in a three phase three wire system with a non-linear load i.e., three phase bridge rectifier and a parallel inductive load. Some power quality aspects like reactive power compensation of linear load, better Total Harmonic Distortion (THD) performance and the power factor improvement are achieved. The result shows the THD of input current achieved as per the IEEE 519-1992 standard. It is observed that STATCOM gives effective compensation for reactive power variation and hence the power quality of distribution systems improved.

Multilevel diode clamped D-Statcom for power quality improvement in distribution systems

Power quality is one big issue in power system and a big challenge for power engineers today. Electrical consumers (or otherwise load devices) expect electrical power received power should be of first-class. Bad quality in electrical power directs to fuse blowing, machine overheating, increase in distribution losses, damage to sensitive load devices and many more. DSTATCOM is one of the FACTS controllers designed to improve the quality in electrical power and thus improving the performance of distribution system. This paper presents a multilevel DSTATCOM topology to enhance power quality in power distribution system delivering high-quality power to the customer load devices. Diode-clamped structure is employed for multi-level DSTATCOM structure. ‘PQ’ based control strategy generates reference signal which is further processed through level-shifted multi-carrier PWM strategy for the generation of gate pulses to multi-level DSTATCOM structure. Simulation work of proposed system is developed and the result analysis is presented using MATLAB/SIMULINK software. Performance of multi-level DSTATCOM topology is verified with fixed and variable loads.

Performance Evaluation of Unified Power Quality Conditioner for Mitigation of Power Quality Issues using Genetic Algorithm Controller

Research is focusing on the improving power quality in distribution system based on unified power quality conditioner device. Each converter has six switches and these switches are controlled in order to mitigate power quality issues. An eight switch UPQC topology is proposed to reduce the harmonics and some precincts such as more switching stress, high value of DC link voltage etc. The UPQC function is primarily identified by the estimation of compensation signals precisely and rapidly. The predominantly focus on improve the power quality in distribution system using flexible ac transmission system connected with grid. In order to reducing the total cost of the system, minimization of number of switches is essential. But it is a challenging task for every researcher. The topology of UPQC can be modified into eight switch topology and the results are validated for nonlinear loads, sag and swell conditions. From the results, it is concluded that genetic algorithm gives encouraging results.

저압직류 배전계통에서 PV가 전압 불평형에 미치는 영향에 관한 연구

Since the multiple PVs will be connected with bipolar Low-Voltage DC (LVDC) distribution system in the future, several problems caused by PV should be analyzed. In order to speed up to introduction of LVDC distribution system, the effect of PV on the voltage unbalance, which is one of the several issues, should be surely studied because it can lead to the power loss and debase the power quality of LVDC distribution system. This paper has analyzed the voltage unbalance by classifying upstream and downstream of PV. As a result, PV contributes the voltage unbalance to upstream area of Point of Common Coupling (PCC). For downstream area of PCC, however, the voltage unbalance caused by PV is absent theoretically and the voltage unbalance occurred by upstream is just sustained in downstream. Finally, this paper has modeled a test system using ElectroMagnetic Transients Program (EMTP) and the proposed results are verified by the simulation for several cases.

ANFIS‐fuzzy logic based UPQC in interconnected microgrid distribution systems: Modeling, simulation and implementation

This study focuses on the improvement of the power quality in interconnected power distribution systems using connected microgrids. The power quality issues at the secondary distribution level are addressed using a unified power quality conditioner, which aids in controlling voltage imbalances and current harmonics. Further, a power control method, adaptive network-based fuzzy inference system, is proposed as a global solution by installing independent compensating devices at the point of common coupling. The proposed strategy can improve the power quality in traditional installations because the proposed unified power quality conditioner method maximizes power utilization and improves the efficiency of the system. The microgrids integrate renewable energy sources, which generate green energy with low loss. Case studies, a prototype, and simulations via MATLAB/Simulink are used to validate the proposed method, and the results prove the enhancement in power quality control. The proposed control strategy had a response time of 0.3 s, reduced peak voltage distortions, and restored the voltage at the interconnecting point to a normal level. The total harmonic distortion of currents decreased from 21.13% to 14.74% when a PI technique was used to control the UPQC-P, and the proposed adaptive network-based fuzzy inference system-based UPQC-P reduced the harmonic content to 2.43% from 21.13%.

3P4SW and 3P9SW Based UPQC Topologies to Improve the Power Quality in Medium Voltage Distribution System

Background: The undesirable effect of power quality issues on distribution system due to power electronics based controllers; it is highly desired to design a novel power quality conditioner with a minimum number of switches. The proposed configuration reduces the switching loss and also effectively alleviates the power quality issues. This paper introduces the configuration of 3P4SW (Three Phase Four Switch) UPQC (Unified Power Quality Conditioner) for both shunt and series APF (Active Power Filter) as well as 3P9SW (Three Phase Nine Switch) UPQC topologies, which can be implemented in medium voltage power grid. The major challenge of phase balance with only four switches in UPQC is accomplished by adaptive Self-tuning PID using neuro-fuzzy logic control and adaptive reference current generation scheme. This controller improves sag and swells compensation with better angle control via shunt and series converter performance and passive components design. The efficacy of proposed topology is tested on MATLAB/Simulink software and results are compared with the existing three phase six switch configuration (3P6SW). Methods: The main objective of this work is to identify the most suitable configuration of UPQC to mitigate the power quality issues in power distribution system. to achieve this goal a Synchronous reference frame theory is used to generate the pulses in the back to back connected VSI in UPQC. Results: The suggested topologies should not compromise with the nominal functions of the controller; hence from the simulation analysis it clear that the 3P4SW UPQC, as well as 3P9SW UPQC topologies, will fulfill the given constraints and also it maintains the magnitude of the load voltage as per the standard values. Also, the THD percentage is maintained well within the IEEE standard. Conclusion: The proposed topologies can be implemented for medium voltage distributed system with improved power quality.

Non-Linear-Variable-Gain Fuzzy Control with Finite Control Set Model Predictive Based DSTATCOM System to Improve Power Quality in Distribution System

In this paper, a Takagi-Sugeno (T-S) fuzzy control structure with model predictive current control-based distribution static compensator (DSTATCOM) is proposed to improve power quality in distribution system. This control technique is based on proposed instantaneous symmetrical component and active power (ISCAP) method for reference generation, T-S fuzzy control for quick stabilisation of DC-link voltage to achieve faster tracking of reference currents and model predictive control for switching signals generation without need of modulators. This combined effort enhances the compensation capability of the system as well as making the system cost effective. Through simulation and real-time experimentation it is found that proposed controller has improved performance in terms of harmonic elimination, power factor correction, quick stabilisation of DC-link voltage and reactive power compensation. Finally this controller is employed with real-time hardware-in-the-loop (HIL) based OPAL-RT 5600 system with RTDS hardware OP5142 which is incorporated with front end processor Xilinx spartan-3 XC3S5000.

Nonlinear-variable-gain fuzzy control with finite control set model predictive-based DSTATCOM system to improve power quality in distribution system

Nonlinear-variable-gain fuzzy control with finite control set model predictive-based DSTATCOM system to improve power quality in distribution system

Modified whale optimisation-based optimal location of UPQC in distribution system for power quality improvement

A number of researchers has studied the unified power quality conditioner (UPQC) as an eventual solution to enhance the power quality in the electrical distribution system. However, due to the high cost, the location or position of UPQC in distribution system needs to be decided with immense care and must preferably be solved as the optimisation problem. This paper presents a power quality improvement model based on a new modified optimisation algorithm, namely worst solution linked whale optimisation algorithm update (WS-WU). The proposed algorithm finds the optimal location of the UPQC device concerning the power system losses, UPQC cost, and voltage stability index as well. The experimentation is carried out in both IEEE 33 and 69 bus systems. The performance of the proposed model is compared over other conventional methods in terms of performance and convergence analysis, and proves the superiority of the proposed method.