The positive-feedback-based anti-islanding schemes invented by the authors are highly effective in preventing islanding without causing any degradation power quality. This paper presents basic principles of these and their design guidelines. Moreover, performance is investigated for inverter-based distributed generators (DGs). parametric study reveals factors significantly influencing schemes. simulation results demonstrate effectiveness

The formulation and computation of an optimal load shedding time algorithm is presented. This new concept was developed as enhancement to the application for corrective control support future islanded power systems with anticipated, enhanced communications infrastructure. methodology combines nonlinear mathematical programming discretized differential-algebraic equations estimate amount be shed well best it. Several simulated scenarios are studied results

This paper presents a medium-voltage (MV) (12.47 kV), 350 kW electric vehicle (EV) fast charger using 10 kV SiC MOSFETs. Detailed system design procedure based on the MOSFET characterization is presented to provide guide converter development. Taking advantage of MOSFET's high voltage blocking capability and efficient switching performance, single module power density designed with DC/DC stage operates at 25 kHz simulated efficiency exceeds 98%, input current THD lower than 2%. With all...

This paper discusses of all the consequences and effects after loss electrical systems caused by hurricane Maria on island Puerto Rico. Rico is in Caribbean very susceptible to catastrophes due natural events which cause different social population. In this article, major affected areas will be mentioned, from water communications health economy Hurricane Maria. We mention fragility country's infrastructure possible measures re-establish these services most expeditious manner. The disasters...

Limited access to transmission lines after a major contingency event can inhibit restoration efforts. After Hurricane Maria, for example, flooding and landslides damaged roads thus limited travel. Transmission are also often situated far from maintained roadways, further limiting the ability repair them. Therefore, this paper proposes methodology assessing Puerto Rico’s infrastructure (i.e., lines) identify potentially hard reach areas due natural risks or distance roads. The approach...

Due to the increasing penetration level of distributed energy resources (DER), especially photovoltaic (PV) systems, IEEE 1547 standard was revised attend utility owners claim voltage and frequency support from DER. The 2018 revision Standard stipulates that PVs should when or abnormalities occurs, ride-through those events. This new requirement increases non-detection zone (NDZ) area available anti-islanding methods, therefore, possibility unintentional islanding due algorithm failure....

With increasing interest in renewable energy, more distributed energy resources (DERs) are being connected into the grid. Islanding conditions occur when a DER disconnects from grid but remains energized. The Sandia Frequency Shift (SFS) is an islanding detection technique that introduces small perturbation current phase angle of photovoltaic (PV) inverter, with use positive feedback, triggering under frequency or over protection occurs. Herein, this work presents PV inverter model utilizes...

This paper presents an energy management strategy by opening and closing switches in a dynamic microgrid. microgrid consists of several groups containing grid following (GFL) photovoltaic (PV) inverters, forming (GFM) storage load which can be connected disconnected from the main Optimization for seeks to minimize consumed with constraint continuously supplying critical load. The algorithm is tasked genetic algorithm. evaluates all parameters as result, delivers states power reference...

Grid-forming (GFM) inverters that support photovoltaic (PV) and dynamic microgrids, expand contract depending on available resources, must adapt. Unlike common micro grid approaches require significant financial investments to maintain operations of a system set size, the approach presented here provides necessary resilience for critical load at reduced cost. To work, GFM inverter appropriate voltage frequency as magnitude PV output loads change quickly during switching event acts reduce...

Photovoltaic (PV) inverters connected to electrical grids are required detect and respond Unintentional Islanding (UI) conditions appropriately. The IEEE Std 1547.1-2020 specifies test procedures, based on resonant parallel RLC loads, evaluate the ability of PV disconnect under UI conditions. This paper proposes a prototype Power Hardware-in-the-Loop (PHIL) testing console with Human Machine Interphase (HMI) virtual load Cat. B tests. Traditional procedures rely physical elements, which...

In this paper, the development of a mathematical model for islanding detection method based on concept digital twin is presented. The estimates grid impedance seen by distributed energy resource. proposed algorithm has characteristics passive and active methods. Using discrete state-space representation dq0 axis power system as equality constraints, optimized to match interest. use estimated parameter identify difference between normal operation scenarios. Selecting arbitrary initial values,...

Due to the increased penetration in Distributed Energy Resources (DERs), especially Photovoltaic (PV) systems, voltage and frequency regulation has become a topic of interest. Utilities have been requesting DER support for almost two decades. Their request was addressed by standards such as IEEE Std 1547-2018. With continuous improvements inverters’ ability control their output voltage, power, frequency, group advanced techniques grid is now required interconnection standard. These are known...

An inverter is a power electronics circuit that can convert DC into AC power. Inverters have wide range of applications, from battery-powered devices to renewable energy systems such as photovoltaics. Typically, inverters rely on switching create an signal. In most cases, these are arranged in the form H-bridge, topology taking its name arrangement devices. Although utilizing single H-bridge achieve either two or three voltage levels, use multiple H-bridges increases levels well voltage....

Recently proposed positive-feedback-based anti-islanding schemes (AI) are highly effective in preventing islanding without causing any degradation power quality. This paper aims to analyze the performance of these quantitatively context dynamic models inverter-based distributed generators (DG). In this study, characteristics active methods discussed and design guidelines derived.

The high penetration of photovoltaic (PV) distributed energy resources (DER) facilitates the need for today's systems to provide grid support functions and ride-through voltage frequency events minimize adverse impacts on distribution power system. These new capabilities its requirements have created concerns that autonomous unintentional islanding (UI) algorithms are not sufficient prevent a condition were loss utility is detected. Type tests in IEEE 1547-2018 evolved thoroughly evaluate...

Power Hardware-in-the-Loop (PHIL) enables the integration of a hardware device into real-time (RT) simulation environment. This allows testing performance physical under real operating conditions before it is connected to an actual system. When developing RT models, there no consideration how impacts system because these are not typically modeled. To reduce risks associated instability from in environment using PHIL platform, high-fidelity model that represents all components platform can be...