太陽光発電の最大利用に向けた低圧配電系統の需要・供給側におけるエネルギーマネジメントに関する研究

早大学位記番号:新7825早稲田大

Review of microgrid benchmark networks & standards

The SIRFN Microgrid Task has a particular focus on laboratory testing and validation of components and systems related to microgrids. The task brings together a network of test laboratories and researchers to share best practices and devise common methods of testing. The high level overview of the task activities is shown in the poster, where it can be seen that the activities range from exchange of knowledge and experiences to definition of benchmarks and laboratory implementation of testing procedures related to test cases. The poster will present an overview of the Microgrid task and its recent work on reviewing microgrid benchmark networks and standards relating to microgrids

Advanced laboratory testing methods using real-time simulation and hardware-in-the-loop techniques : a survey of smart grid international research facility network activities

The integration of smart grid technologies in interconnected power system networks presents multiple challenges for the power industry and the scientific community. To address these challenges, researchers are creating new methods for the validation of: control, interoperability, reliability of Internet of Things systems, distributed energy resources, modern power equipment for applications covering power system stability, operation, control, and cybersecurity. Novel methods for laboratory testing of electrical power systems incorporate novel simulation techniques spanning real-time simulation, Power Hardware-in-the-Loop, Controller Hardware-in-the-Loop, Power System-in-the-Loop, and co-simulation technologies. These methods directly support the acceleration of electrical systems and power electronics component research by validating technological solutions in high-fidelity environments. In this paper, members of the Survey of Smart Grid International Research Facility Network task on Advanced Laboratory Testing Methods present a review of methods, test procedures, studies, and experiences employing advanced laboratory techniques for validation of range of research and development prototypes and novel power system solutions

Creation of a Database of Uncertainties for ICSBEP Handbook and Tool for Covariance Generation

The creation of a database of uncertainties for criticality experiment benchmarks is under construction and intended to be incorporated into a future version of the database for ICSBEP, DICE. As a first step, Section 2 and 3.1 data have been extracted from ICSBEP benchmark evaluations and homogenized in a manner that allows searching and trending uncertainties across evaluations. One of the primary objectives of building such a database is to facilitate creation of covariance matrices between experimental uncertainties, as often, only the diagonal term has been evaluated leading to cases being treated as independent during uncertainty analysis. This assumption does not reflect a best estimate. The database-features lower the effort required to create covariance???s, so analysts can focus on estimating whether uncertainties are shared between cases, rather than the mechanical aspects of uncertainty extraction and matrix generation. Now users can quickly create transparent estimates of covariance. Using the sheet an attempt has been made to read the evaluations and then provide an estimate of the covariance by estimating which uncertainty components are shared between cases. While it is difficult to evaluate the ???correctness??? of the generated covariance???s, the paper has run the over 500 of LCT cases with experimental covariance, through a generalized least squares tool, TSURFER, both with experimental covariance???s and without and the results are analyzed. Further work is required in the area of testing the impact on real world applications

Characteristic Analysis and Indexing of Multimachine Transient Stabilization Using Virtual Synchronous Generator Control

As distributed power sources via grid-connected inverters equipped with functions to support system stabilization are being rapidly introduced, individual systems are becoming more complex, making the quantification and evaluation of the stabilizing functions difficult. Therefore, to introduce distributed power sources and achieve stable system operation, a system should be reduced to a necessary but sufficient size in order to enable the quantification of its behavior supported by transient theory. In this study, a system in which multiple distributed power supplies equipped with virtual synchronous generator control are connected is contracted to a two-machine system: a main power supply and all other power supplies. The mechanical torque of each power supply is mathematically decomposed into inertia, damping, synchronization torques, and the governor effect. The system frequency deviations determined by these elements are quantitatively indexed using MATLAB/Simulink. The quantification index displayed in three-dimensioned graphs illustrates the relationships between the various equipment constants of the main power supply, the control variables of the grid-connected inverter control, and the transient time series. Moreover, a stability analysis is performed in both the time and frequency domains

Deployment of low-voltage regulator considering existing voltage control in medium-voltage distribution systems

Many photovoltaic (PV) systems have been installed in distribution systems. This installation complicates the maintenance of all voltages within the appropriate range in all low-voltage distribution systems (LVDSs) because the trends in voltage fluctuation differ in each LVDS. The installation of a low-voltage regulator (LVR) that can accordingly control the voltage in each LVDS has been studied as a solution to this problem. Voltage control in a medium-voltage distribution system must be considered to study the deployment of LVRs. In this study, we installed LVRs in the LVDSs in which the existing voltage-control scheme cannot prevent voltage deviation and performed a numerical simulation by using a distribution system model with PV to evaluate the deployment of the LVRs

Reviewing Control Paradigms and Emerging Trends of Grid-Forming Inverters—A Comparative Study

Grid-forming inverters (GFMs) have emerged as crucial components in modern power systems, facilitating the integration of renewable energy sources and enhancing grid stability. The significance of GFMs lies in their ability to autonomously establish grid voltage and frequency, enabling grids to form and improve system flexibility. Discussing control methods for grid-forming inverters is paramount due to their crucial role in shaping grid dynamics and ensuring reliable power delivery. This paper explores the fundamental and advanced control methods employed by GFMs, explaining their operational principles and performance characteristics. Basic control methods typically involve droop control, voltage and frequency regulation, and power-balancing techniques to maintain grid stability under varying operating conditions. Advanced control strategies encompass predictive control, model predictive control (MPC), and adaptive control, which influence advanced algorithms and real-time data for enhanced system responsiveness and efficiency. A detailed analysis and performance comparison of different control methods for GFM is presented, highlighting their strengths, limitations, and suitability for diverse grid environments. Through comprehensive studies, this research interprets the ability of various control strategies to mitigate grid disturbances, optimize power flow, and enhance overall system stability

Verification of power hardware-in-the-loop environment for testing grid-forming inverter

Grid-forming inverters (GFMIs) are promising technologies that can replace some of the capabilities traditionally provided by synchronous generators (SGs), such as inertial response. While there have been many simulation-based studies on GFMIs, performance testing has not been adequately discussed. Power hardware-in-the-loop (PHIL) simulation is an attractive option for testing GFMIs. The interaction between GFMI and power systems can be observed under a variety of conditions, including low-inertia and contingency conditions. Since PHIL testing was primarily used for grid-following inverters (GFLIs), the PHIL configuration needs to be adjusted to test GFMIs, which respond faster to changes in grid voltage than GFLIs. This paper proposes the PHIL setup for testing GFMIs. It utilizes the PHIL interface developed for testing GFLIs and adjusts it for testing GFMIs. The stability and accuracy of the PHIL testing are evaluated in terms of frequency stability in low-inertia power systems by comparing test and simulation results

Performance analysis of grid-forming inverters in existing conformance testing

Grid-forming (GFM) inverters are promising technologies in future power systems. Although the voltage-source characteristic of the GFM inverter has been validated to enhance the stabilities in low-inertia power systems, modifying protective function mechanisms is needed from grid-following (GFL) inverters with the current-source characteristic. Therefore, the protective functions that coexist with grid stabilization capabilities in GFM inverters and their verification methods should be studied for practical deployment. This paper applies the existing Japanese conformance testing on prototypes of GFL and GFM inverters to reveal issues in the existing conformance testing framework, which was not designed to consider the voltage-source characteristics of GFM inverters. The test results identify the three main issues of GFM inverters in the existing test framework. The discussion based on the results will provide helpful knowledge to design future provisions on the functional requirements of GFM inverters and their verification methods