Distributed Power Flow Controller Research Articles

Harmonics reduction and power quality improvement in distributed power flow controller by SVPWM and MGWO technique

Harmonics reduction and power quality improvement in distributed power flow controller by SVPWM and MGWO technique

Harmonic suppression control strategy of distribution networks based on the distributed power flow controller

New energy and multiple loads, such as distributed wind–solar storage and charging, are connected to the distribution network through power electronic converters, which increases the harmonic content in the distribution network and causes operational safety risks. In this paper, the mathematical model of harmonic current and harmonic power content in a distribution network is constructed by an equivalent circuit and vector diagram. The distributed power flow controller is proposed for harmonic control of the distribution network. The mathematical expressions of the harmonic current and harmonic power based on a distributed power flow controller are constructed, and the control strategy of the distributed power flow controller for harmonic control is proposed. The simulation results show that the proposed method can effectively suppress the fifth and seventh harmonics of the distribution network.

A Modern Distribution Power Flow Controller With A PID-Fuzzy Approach : Improves The Power Quality

Technological improvements have led to an increase of nonlinear loads, which in turn has a significant impact on the quality of power transmission. It is imperative that the level of energy purity conveyed by a transmission line be elevated. The key factors influencing power transmission are line impedance, sending end voltage, and receiving end voltage. Harmonic currents are made by nonlinear loads, which can cause system resonance, capacitor overloading, less efficiency, and a change in the amount of the voltage. The Distributed Power Flow Controller (DPFC) is a recently developed Flexible AC Transmission System (FACTS) device that utilizes the distributed FACTS (D-FACTS) idea. Unlike the Unified Power Flow Controller (UPFC), which employs a single large-sized three-phase series converter, the DPFC incorporates several small-sized single-phase converters.

Egret Swarm Optimized Distributed Power Flow Controller for Power Quality Enhancement in Grid Connected Hybrid System

Egret Swarm Optimized Distributed Power Flow Controller for Power Quality Enhancement in Grid Connected Hybrid System

Power quality enhancement of solar–wind grid connected system employing genetic-based ANFIS controller

Abstract The demand for electricity globally has led to the search for renewable energy resources for power generation and attaining it in an eco-friendly manner. The solar photovoltaic systems and wind-based generators of power are regarded as primary resources of renewable energy and are called Distributed Generation units as they are scattered in nature. These are operated with bidirectional converters by providing auxiliary services at grid side and load side in either mode of microgrid operation. Besides, the DC power generation units’ integration gets converted into AC system by means of inverters. These types of systems not only increase voltage and current harmonics and power frequency deviations but also drive the distribution system to risky operating zone. This emphasizes the stipulation of advanced control schemes for microgrid architecture. Consequently, power electronic converters introduce harmonics in the system and affect system performance. To report these expanded issues, the authors recognized an advanced custom power device entitled Distributed Power Flow Controller (DPFC). In this study, the proposed system on solar–wind-based hybrid energy approach has been examined primarily through the strategy of DPFC mechanism. Later, the system has been examined with Genetic Algorithm (GA)-based fuzzy logic controller and GA-based adaptive neuro fuzzy inference system controller for shunt control of context built with DPFC mechanism. Furthermore, the validated results are verified using MATLAB/Simulink software.

Research on the harmonic currents rates for the exchanged energy of unified distributed power flow controller

Research on the harmonic currents rates for the exchanged energy of unified distributed power flow controller

Distributed power flow controller based on fuzzy-logic controller for solar-wind energy hybrid system

The demand of electricity globally led to the concept of renewable energy resources for power generation that are eco-friendly and freely available from nature. The solar photovoltaic systems and wind-based power generators are considered as primary renewable resources and are called as Distributed Generation units as they are scattered in nature. These are operated with bidirectional converters by providing auxiliary services at grid side and load side in either mode of microgrid operation. Besides, the DC power generation units’ integration gets converted into AC system by means of inverters. These types of systems not only increase voltage and current harmonics, power frequency deviations but also drive the distribution system to risky operating zone. This emphasizes the stipulation of advanced control schemes for microgrid architecture. Consequently, power electronic converters introduce harmonics in the system and affect the system performance. To report these expanded issues, the authors recognized an advanced custom power device entitled distributed power flow controller. The proposed hybrid solar-wind energy system is first studied with a distributed power-flow controller. Later the system is examined by replacing proportional integral controller with fuzzy logic controller (FLC) for shunt control of distributed power-flow controller. To validate the investigations, MATLAB/Simulink software is used.

Stabilization of frequency in Multi-Microgrid system using barnacle mating Optimizer-based cascade controllers

This paper presents a new control strategy in multi-microgrid system for supressing the variations of frequency and of tie-line power flow due to intermittent nature of renewable sources and frequently varying load demands. A novel cascade combination of fractional order-based integral derivative and proportional integral derivative with filter called CFOID-FOPIDN controller is utilized as secondary controller for automatic generation control. In this work, diverse sources such as photovoltaic, wind, diesel engine, fuel-cell, electrical vehicles and battery energy storage systems are considered for investigations under various uncertainties conditions. A newly developed barnacle mating optimizer is presented to tune the CFOID-FOPIDN for diminishing the frequency and tie-line power changes. Moreover, the amalgamation of redox flow batteries and modern flexible alternating current transmission system device like distributed power flow controller is integrated into the system for ameliorating the dynamic stability of the system. The tested outcomes show that the barnacle mating optimizer-based CFOID-FOPIDN controller with the combination of distributed power flow controller and redox flow batteries exhibits low fluctuation rate for frequency (5.6 s for area-1 and 5.5 s for area 2) and tie-line power (6.2 s). Finally, the robustness of the CFOID-FOPIDN is validated under three operating conditions, such as step load perturbations, change in wind speed, irradiance, and change in both wind and irradiance levels.

Block Diagram Representation of Controller Components of Distributed Power Flow Controller

In this paper, an attempt is made to present the controllers used for a power flow controller, termed as Distributed Power Flow Controller (DPFC). This comes under the category of Flexible AC Transmission Systems (FACTS) devices. DPFC emerges from the unified power flow-controller (UPFC), a most powerful FACTS device which can be used for both shunt and series control. So DPFC inherits the same control capability of simultaneous adjustment of line impedance, transmission angle and the bus voltage magnitude, which are the dynamic control parameters. The DPFC control and the functions of the different components for shunt and series controllers of DPFC are presented. These components can be obtained from Simulink Library of MATLAB environment and simulation model is obtained in this paper to check the dynamic response of DPFC.

Research on the output coordinated strategy of a DPFC considering device fault probability

A distributed power flow controller (DPFC) can control the line power flow in a flexible and fast way to meet the requirements of a new power system. However, the output of DPFC sub-units is generally distributed by the even distribution method or proportional distribution method at present. The internal health status and output capacity of the device are not taken into account, which affects the efficiency and service life of the device. In this article, a reliability description method of DPFC based on fault probability is proposed. The coordination strategy of output voltage capability and the number of input sub-units is proposed, and the process of the proposed coordinated strategy for device output is presented. The simulation results show that the proposed coordinated output strategy can address the issue of rapid reliability decline caused by the long-term work of some sub-units and improve the overall reliability of the DPFC.

Design and application of short circuit test scheme for Hu Zhou DPFC project

The short circuit test of distributed power flow controller (DPFC) is still a blank in the world. In order to test the effectiveness and adaptability of DPFC in case of line failure, it is necessary to carry out short circuit tests in DPFC projects. Based on the Hu Zhou DPFC Project, this paper proposes the control and protect strategy of DPFC which is coordinated with the protect strategy of AC line, designs single phase short circuit grounding test scheme of the AC line where DPFC is located. In the application, the action logic of DPFC under single-phase grounding fault is verified, the single phase short circuit test of DPFC were completed for the first time, and the transient voltage and current were obtained. It provides technical support for the popularization and application of DPFC project.

A Proportional Investigation among UPFC and DPFC in a Grid Associated Photovoltaic Organization

Abstract: In this paper a proportional investigation between Unified Power Flow Controller (UPFC) and Distributed Power Flow Controller (DPFC) in a grid incorporated photovoltaic system is performed. A grid connected solar generation scheme with boost converter and voltage source inverter (VSI) is taken as the key model. Due to power quality issues like power oscillations, harmonic distortions, voltage sags and swells, the grid side system has to be absolutely monitored and restricted. One way to mitigate these power quality troubles is by using reactive elements like shunt/series reactor and shunt/series capacitor. The drawback on using these reactive elements is sub synchronous resonance phenomenon. Gratitude to FACTS equipment, which emerged out as power conditioning units and helps to feed power with required standards and free from power quality issues. Among them, the contemporary FACTS devices are Controller Distributed Power Flow (DPFC) and Unified Power Flow Controller (UPFC). Though the aims of both the devices are same but their working principles are different. In this paper the effect of adding a DPFC and UPFC to a solar PV generation system is analysed. A detailed working principle and operation of both the devices were presented. At last, MATLAB/SIMULINK environment is used to evaluate the performances of abovementioned devices.

Performance enhancement of renewable based deregulated system using distributed power flow controller, Redox flow battery, and Tesla power wall battery

ABSTRACT In the upcoming era, when conventional sources will mostly be replaced by renewable energy sources, engineers may face huge problem during controller design. For this large interconnected hybrid automatic generation control (AGC) system, high proficient and intelligent control techniques are needed. Hence, a newly developed fractional order tilt integral derivative double integral filter plus (FOTIDF-II) controller has been proposed in this research work. To overcome slow convergence feature of moth swarm algorithm (MSA), chaotic-based moth swarm algorithm (CMSA) is introduced by incorporating chaos into the MSA algorithm. Afterward, to upgrade the performance of AGC, the newly proposed controller is incorporated to the said system. The gains and fractional order parameters such as order of integrator, differentiator and filter coefficients of the proposed controller are optimized using CMSA optimizing technique. It is observed that the dynamic performance of the proposed CMSA optimized FOTIDF-II controller is better than the CMSA optimized PID. Furthermore, the performance of CMSA in the presence of different flexible AC transmission system (FACTs) and storage devices such as distributed power flow controller (DPFC), redox flow battery (RFB), and Tesla power wall (TPWA) battery (i.e Storage devices) along with proposed controller is compared with MSA-based PID controller with same combination of FACTs controller. Afterwards, superiority of the proposed controller has been judged in three area renewable-based AGC system under realistic environment.

Robust Unit Commitment for Minimizing Wind Spillage and Load Shedding With Optimal DPFC

The distributed power flow controller (DPFC) has a positive effect of UC problem on the network side based on its ability to manage capacity of power flow. This study presents a novel two-stage robust model to optimize the status of the generator and location–allocation of the DPFC, while simultaneously considering wind and load uncertainties. The column-and-constraint generation (CCG) method is utilized to solve the two-stage problem into the master problem and the subproblem iteratively. The optimal status of the generator and location of the DPFC can be easily obtained with the master problem, and the dispatch solution and compensation level of the DPFC are solved in the subproblem. We conduct the IEEE 24 bus system to verify the performance of the proposed procedure. There are effects on wind spillage/load shedding and generator dispatch scheduling planning once the DPFC is injected. Detailed simulation results illustrate the effect of the proposed approach.

Two-Stage Optimal Location Allocations of DPFC Considering Wind and Load Uncertainty

Distributed power flow controller (DPFC) has a considerable potential to regulate the power flow and generator rescheduling continuously. This study presents a novel two-stage stochastic model for optimal location allocations of the DPFC coupled with the interactions of DPFC to search for the optimal solutions. The Benders decomposition is utilized to reformulate the two-stage problem into the master problem and the subproblem. The optimal solution can be easily obtained with the master problem and subproblem iteratively. The relaxed DC power flow with a DPFC in the master problem accelerates the efficiency of optimal locations under a base condition. Slack variables are incorporated in the subproblem to check the feasibility of relaxed AC power flow. The optimal compensation levels of DPFC at different load/wind scenarios are optimized in the subproblem. The IEEE 118 bus system is conducted to verify the performance of the proposed procedure. The DPFC has positive impacts on unit costs, voltage performance, wind absorption, and power losses. Detailed simulation results illustrate the effect of the proposed approach.

Optimal output power coordinated control strategy of distributed power flow controller

Distributed power flow controller (DPFC) is composed of multiple sub-units distributed on the line, which improves the power flow transmission capacity and ensures high reliability of the line. The overall performance and power losses of DPFC are the major concern, which is largely determined by the output power assigned to each sub-unit. This paper investigates the operating loss of its sub-units and analyzes the output of the DPFC device based on the topology of DPFC. Considering the total loss of the DPFC device, the capacity utilization rate of the sub-units and relative constraints, an optimal output power coordinated control strategy of DPFC multi-sub-unit is proposed. The simulation platform of PSCAD/EMTDC is used to develop the simulation model of a typical 110 kV system consisting of 10 groups of sub-units with different capacities. The simulation results show that the optimal output power coordinated control strategy proposed in this paper can greatly reduce the total loss of the device compared with the traditional methods, such as equipartition method and the capacity proportion method. And the capacity utilization rate of the operated sub-units can reach over 87.5%.

Simultaneous controllers for stabilizing the frequency changes in deregulated power system using moth flame optimization

This paper introduces a stochastic idea for two-area automatic generation control (AGC) of the restructured system for enhancing the system dynamic performance. In this work, a new 2-degree of freedom of proportional-integral derivative-fractional order proportional derivative with filter (2DOF PID-FOPDN) approach is proposed for the AGC two area system. To ensure realization of optimal gains of the controller, a novel nature-inspired moth-flame optimization (MFO) is suggested using integral of time multiplied absolute error (ITAE) model. The performance of MFO-based 2DOF PID-FOPDN is evaluated against Cuckoo search (CS), Bat algorithm (BA), and Teaching learning-based optimization (TLBO) approaches in different contract scenarios of deregulated system. Further work to reduce the changes in tie-line has been applied through different FACTS controllers, such as Distributed power flow controller (DPFC), Thyristor-controlled series capacitor (TCSC), Unified power flow controller (UPFC), and Static synchronous series compensator (SSSC); integrated into the AGC system with the co-ordination of Ultra-capacitor (UC). The results indicate that the MFO-based 2DOF PID-FOPDN shows superior performance with DPFC-UC over other approaches in all contract scenarios of liberalized system. A sensitivity analysis is examined to recognize the robustness of the suggested approach under ± 25% deviation in loading and system parameters.

Performance Improvement of Grid Interfaced Hybrid System Using Distributed Power Flow Controller Optimization Techniques

The main aim of this paper is to introduce a framework for the design and modelling of a photovoltaic (PV)-wind hybrid system and its control strategies. The purpose of these control techniques is to regulate continuous changes in the operational requirements of the hybrid system;currently, in power system networks, the distribution of energy plays a major role in maintaining power reliability in distribution systems. In this study, the proposed hybrid system was incorporated with a combined PV and wind energy system. Maximum power point tracking (MPPT) methods have been proposed to achieve maximum efficiency from the designed system. In addition, this study focused on improving the stability of the hybrid system. To improve the power quality and transient stability of the proposed system, we introduce a novel control strategy called the distributed power flow controller (DPFC) implementation with an optimization technique called the lion optimization algorithm(LOA)technique. This LOA control technique was developed for the first time in the application of a DPFC controller in a grid-connected system. The control technique was developed using signals from the system parameters, that is, voltage and current. To tune these parameters, this study used fuzzy logic and lion optimization techniques. The proposed system with controllers was tested in MATLAB/Simulink and the results were compared.

Graded start strategy of distributed power flow controller

The distributed power flow controller (DPFC) realizes large-scale power flow control through the series connection of sub-modules. The larger the DPFC capacity and the level of sub-modules connected to the system, the greater the impact that may be caused. Starting from the DPFC structure and operating principles, the paper proposes graded start strategy of DPFC based on the world’s first 220kV DPFC demonstration project. The strategy coordinates each sub-module to start step by step and unlock under lower DC voltage through the centralized control system, reduces system power fluctuation, and reduces the overall start-up time through the information interaction between the centralized control and the multi-series valve control systems in sub-modules. The test results of the HUZHOU DPFC demonstration project show that the strategy proposed can reduce the active power fluctuation amplitude of the 4 sub-modules DPFC by 75% which have good prospect of engineering application.

Mechanically coupled to Static Distributed Power Flow Controllers (DPFC)

Mechanically coupled to Static Distributed Power Flow Controllers (DPFC)