This paper describes the importance of FACTS devices; it presents the outcome of the study of its reflectance on the performance of power system networks. It seeks to increase and guarantee the fact and accuracy of response systems under disturbance conditions when the phase measurement units are introduced as Real-Time Measurement (RTM) stations. This paper also describes the importance of FACTS devices. The combination of FACTS devices and PMUs is presented to increase the controllability performance of power systems. This paper demonstrates how PMUs measure voltage, current and their angles. It provides, through a communication link, a Phase Angle Data Concentrator (PDC) to make an appropriate decision to correct the power system state using the FACTS device (TCSC). We utilized the Graph-Theoretic Algorithm to optimize the number and location of PMUs. The technique proposed was tested on the Iraqi National Super Grid’s 24bus network, Diyala City’s regional 10bus network and the 14bus IEEE standard test system. The MATLAB/PSAT package was utilized for the simulation of results. It is evident that our proposed algorithm and technique achieved the purpose of this paper as confirmed by the level of accuracy of the results obtained from most of the cases tested.

/pdf/phase-measurement-units-based-fact-s-devices-for-the-3yhbz4z8v5.pdf

Phase Measurement Units based FACT’s Devices for the Improvement of Power Systems Networks Controllability

In recent years, the monitoring and control of the power grid has become an essential objective to prevent system failure. The provision of measurements generated from phasor measurement units (PMUs) can play a significant role in achieving this goal. PMUs can offer synchronized measurements and dynamically measure voltages and current phasors. The estimation of the states of each bus via the installation of PMUs at each node of the bus is not necessary and is hindered by the high cost and complexity of the installation and communication methods. Therefore, a method that reduces the total number of PMUs without affecting the maximum observability and reliability of the power grid is needed. Achieving the minimum number of installed PMUs with maximum observability is the main target of optimal PMU placement. Several techniques are available for resolving this issue, and these techniques lie in two main categories: mathematical techniques and metaheuristic approaches. In the last few years, a huge number of publications have reported different techniques that are based on the principle used and the intended application. Some comprehensive reviews have also been reported a few years ago. This area is an intensively pursued field of study, and many new techniques and important results have been reported after the publication of these reviews. Therefore, there is a need for a comprehensive review of recent research on optimal PMU placement. The present work attempts to provide a critical review of recent literature on optimal PMU placement. We expect this review to be beneficial to researchers and industries that are studying the optimal placement of PMUs in their networks.

/pdf/optimal-pmu-placement-in-a-smart-grid-an-updated-review-4z1836msw2.pdf

Optimal PMU placement in a smart grid: An updated review

This paper proposes a new method for locating high impedance fault in distribution systems using phasor measurement units (PMUs) installed at certain locations of the system. To implement this algorithm, at first a new method is suggested for the placement of PMUs. Taking information from the units, voltage and current of the entire distribution system are calculated. Then, the two buses in which the fault has been occurred is determined, and location and type of the fault are identified. The main characteristics of the proposed method are: the use of distributed parameter line model in phase domain, considering the presence of literals, and high precision in calculating the high impedance fault location. The results obtained from simulations in EMTP-RV and MATLAB software indicate high accuracy and independence of the proposed method from the fault type, fault location and fault resistance compared to previous methods, so that the maximum observed error was less than 0.15%

/pdf/permanent-fault-location-in-distribution-system-using-phasor-519dccd8s8.pdf

Permanent Fault Location in Distribution System Using Phasor Measurement Units (PMU) in Phase Domain

This paper demonstrates the design of robust proportional resonant (PR) controller using negative imaginary (NI) theorem for voltage control of three-phase islanded microgrid (MG) application. While operating MG as the islanded mode, different types of random and unknown load dynamics affect the MG. These loads eventually deteriorate the proper execution of MG-inducing disturbances in voltage and current. Therefore, to improve the performance of the three-phase MG, a simple, second-order controller is designed with the combination of NI theory and PR (NI–PR) controller. This controller is capable of providing higher level of damping as well as excellent stability properties. The stability and effectiveness of this controller are examined through imposing uncertainties, in terms of several load dynamics as well as different fault conditions. The comparison with respect to linear quadratic regulator and model predictive controller also ascertains the robustness of the designed controller. The NI–PR controller and the system are simulated in MATLAB/SIMULINK platform.

Negative Imaginary Theory-Based Proportional Resonant Controller for Voltage Control of Three-Phase Islanded Microgrid

This study proposes a novel technique of cooperative control for a distributed hybrid DC/AC Microgrid (MG) by designing a digital Infinite Impulse Response (IIR) filter-based Proportional-Resonant (PR) current controller. This controller adopts an Adaptive Neuro Fuzzy Inference System (ANFIS) trained by Particle Swarm Optimization (PSO) to control inverter output current while tracking Maximum Power Point (MPP). A hybrid ANFIS-PSO extracts maximum power from both inverter and boost converter-based solar Photovoltaics (PVs) systems quickly and with zero oscillation tracking. The proposed PR controller cancels harmonics while achieving high gain at the resonant frequency (grid frequency). The PR controller offers quick reference signal tracking, grid frequency drift adaptation, easy system design, and no steady-state error. Moreover, this investigation features a PR controller frequency-domain analysis. The proposed technique smooths voltage and improves steady-state and transient responses. Cooperative control is implemented on an IEEE 14-bus MG with distributed communication. The findings indicate that the proposed control technique can regulate MG voltage to obtain a more stable voltage profile. The adopted MG, made up of dispersed resources, is crucial for assessing power flow and quality indicators in a smart power grid. Finally, numerical simulation results are utilized to verify the recommended technique.

https://ieeexplore.ieee.org/ielx7/6287639/6514899/10005160.pdf

A Novel Cooperative Control Technique for Hybrid AC/DC Smart Microgrid Converters

The Microgrid is a power system network which assumes a cluster of loads and microsources operating as a single controllable system providing both power and heat to its local area. This paper presents a Proportional Resonant (PR) controller design in discrete domain for regulating the active and reactive power output for a three-phase AC Micro-Grid system. The PR controller reduces the steady state error and help in synchronous d-q transformation in three phase system. It employs a Voltage Sourced Converter (VSC) which is configured to operate as a current source through an interface L-filter. The power is controlled indirectly by controlling the inverter’s output current. This paper also presents a comparison of THD between Proportional Integral (PI) and Proportional Resonant (PR) controllers and indicates that the THD using Proportional Resonant (PR) controller is less than the Proportional Integral (PI) controller by more than 2%. The complete work is designed and implemented in MATLAB/SIMULINK.

https://ijrer.com/index.php/ijrer/article/download/2644/pdf_2644

Microgrid Design and Control Using a Discrete Proportional Resonant Controller

Review on optimization techniques and role of Artificial Intelligence in home energy management systems

Synchronized phasor measurements have become the measurement technique of choice for electric power systems. They provide positive sequence voltage and current measurements synchronized to within a microsecond. The objective is to use the spanning tree approach and tree search technique for optimal placement of multichannel and minimum channel synchronized phasor measurement units (PMUs) in order to have full observability of Power System. The novel concept of depth of observability is used and its impact on the number of PMU placements is explained.  The spanning tree approach is used for the power system graphs and a tree search technique is used for finding the optimal location of PMUs. This is tested on IEEE-14 and IEEE-30 bus system. The same technique is modified to optimally place minimum channel PMUs on the same IEEE-14 and IEEE-30 bus systems. Matlab tool has been used for fulfilling the objective.

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A Spanning Tree Approach in Placing Multi-channel and Minimum Channel PMU’s for Power System Observability

The radial network is the one which passes through the network without any connection to other supply. It is used for isolated loads like rural areas. Different forward-backward sweep algorithms exist for the load flow analysis of radial distribution systems. A new method of load flow analysis for radial distribution system is explained in this paper. This method is worked out by considering voltage independent loads and voltage dependency loads. The voltage profile results of the proposed method are compared with ratio flow method. Adequate simulations are performed by using Matlab.

A simple load flow method for radial distribution system

The Non-Conventional energy sources play a key role in present power markets to meet the electrical energy demand on the grid. These solar modules are connected to the grid through converters for converting the DC to AC power. The quality of the power from these inverters should be good and hence it is required to limit the harmonics from these inverters as much as possible. This can be done with the help of current controller of inverter which controls the quality of the current supplied by the PV Inverter to the grid. One of the most commonly used current controllers is the PI controller. But due to presence of dynamics in the integral term, the PI control has steady-state error in following the sinusoidal reference. Another commonly used current controller is the Proportional Resonant (PR) controller. As most of the controllers are of digital type, the resonant controllers has zero and pole mapping during the conversion of continuous to discrete time domain and hence it is employed in discrete mode. In this work, the modified Tustin discretization and Euler discretization methods are implemented for current controller of the inverter and compared with each other with respect to total harmonic distortion (THD) of the current and voltage signal from the inverter. This work is designed and implemented in MATLAB/Simulink tool.

Srihari Mandava

Papers

Microgrid Design and Control Using a Discrete Proportional Resonant Controller

Review on optimization techniques and role of Artificial Intelligence in home energy management systems

A Spanning Tree Approach in Placing Multi-channel and Minimum Channel PMU’s for Power System Observability

A simple load flow method for radial distribution system

Control of Micro-grid by Discretized PR Controller Using Tustin Frequency Pre-wrapping Method