電源系統の自動設計のための一手法

This thesis aims to provide insight into the necessary power system operation and control developments to facilitate a sustainable, safe and reliable electric power supply now and in the future. The primary objective is to enhance the interconnected power system situational awareness with the aim of reinforcing the reliability of power systems. First, the thesis elaborates on the existing and emerging operational challenges of modern power systems and identifies the required power system developments to overcome them. Next, it focuses on state-of-the-art Synchronised Measurement Technology (SMT) supported Wide-area Monitoring Protection and Control (WAMPAC) of power systems. In this context, a cyber-physical experimental testbed for online evaluation of the emerging WAMPAC applications under realistic conditions is developed. Following, to fill the scientific gap between the IEEE Std. C37.118-2005 (communication part) and IEEE Std. C37.118.2-2011 specifications and their implementation, the MATLAB supported Synchro-measurement Application Development Framework is developed. Next, to improve situational awareness of power systems, two SMT-supported algorithms are proposed. The first algorithm is suitable for online detection of disturbances, observed as excursions in SMT measurements, in AC and HVDC power grids. Whereas the second algorithm is suitable for online identification of grouping changes of slow coherent generators in an interconnected power system during quasi-steady-state and the electromechanical transient period following a disturbance. Finally, further research directions towards the Control Room of Future are presented.

The constant failure in cyber security in power systems and substation automation that has crippled business activities that mostly depend on power to run their routine activities are caused by Lack of Adequate Security Measures, Human Error, Outdated Software and Hardware, Insufficient Training and Awareness, Insider Threats, Weak Access Control Mechanisms, Inadequate Network Segmentation, Failure to Patch Vulnerabilities, Complexity of the System, Third-Party Vendor Risks and Denial of Service (DoS) Vulnerabilities. This is surmounted by introducing improved cyber security in power systems and substation automation using intelligent based system. To achieve this, it is done in this procedure characterizing and establishing the causes of failure in cyber security in power systems and substation automation, designing a SIMULINK model for cyber security in power systems and substation automation, designing a rule base that will reduce the causes of failure in cyber security in power systems and substation automation,training ANN in the rule base for effective reduction of causes of failure in cyber security in power systems and substation automation, developing an algorithm for the process, designing a SIMULINK model for improving cyber security in power systems and substation automation using intelligent based system and validating and justifying the percentage of improvement in the reduction of causes of failure in cyber security in power systems and substation automation. The results obtained were the conventional Lack of Adequate Security Measures that cause failure in improving cyber security in power systems and substation automation was 25%. On the other hand, when an intelligent based system was incorporated into the system, it drastically reduce the cause failure in improving cyber security in power systems and substation automation to 21.53%, the conventional outdated software and hardware that cause failure in improving cyber security in power systems and substation automation was 15%. Meanwhile, when an intelligent based system was inculcated in the system, it became reduced to 12.92% thereby enhancing the performance of cyber security in power systems and substation automation by 2.08%, the conventional Weak Access Control Mechanisms that cause failure in improving cyber security in power systems and substation automation was 8%. However, when an intelligent based system was integrated in the system, it was reduced to 6.9% and the conventional Denial of Service (DoS) Vulnerabilities that cause failure in improving cyber security in power systems and substation automation was 2% while when an intelligent based system was incorporated in the system, it automatically reduced to 1.7%. Finally, with these results obtained, It vehemently shows that the percentage improvement in cyber security in power systems and substation automation was 0.3%.

A cybersecurity assessment framework for virtual operational technology in power system automation

With the constant improvement of the economic level and the continuous development ofscience and technology, people are increasingly paying attention to the security and stabilityof Power Systems, which makes the power system automation become a research focus of thepeople gradually. Power system automation control technology at this stage is in the periodof rapid development, its information processing ability strengthens constantly, improves theinformation processing efficiency constantly, and broadens application scope for promotingthe development of the country's electric power industry. This paper introduces thedevelopment of electric power system automation control technology, the basic principle, andanalyzes the way of the realization of the power system automation and the developmentdirection of power system automation control technology, laying the foundation for the next study.

With the development of codec technology and wireless broadband access system of the opening, use them as a hosted network, for low bit rate wireless video monitoring system is more and more get the attention of people. Based on CDMA network of the Internet are introduced in detail based on CDMA wireless communication for the working principle of the image monitoring and designed to CDMA mode of private network can be applied to power plant water station in remote areas, such as image monitoring scheme, involving network mode, the system monitoring module unit interior, related compression algorithm and background removal algorithm and should have the function of the system the background, proposed to improve the development direction of the wireless monitoring system. Along with the increasingly mature CDMA remote image monitoring system, remote monitoring of power system automation will inject fresh blood, to make contribution to the improvement of electric power automation. Introduction With the continuous development of electric power automation technology, make the power system automation level gradually improve, power plants, substations, stations and so on all need by monitoring system gradually achieve less people, no regulation, in order to improve production efficiency. Remote image monitoring is the telemetry, remote and remote control of further added. More and more remote image monitoring system of the electric power enterprises as a new means of power system automation management [1]. Remote power monitoring system was built in the center of the electric power dispatching management monitoring center, set up in each substation video, audio, data acquisition unit, or in power plants, substations, etc to set up the monitoring center on their equipment, video surveillance equipment and working environment [2]. Monitoring center of the data of each monitoring unit image monitoring and surveillance, can real-time, accurate, and directly understand and master the situation of the monitoring unit, and respond to what is happening in time, and can carry on the storage to the related data, analysis, provides forceful support for later decisions and to improve, to adapt to the needs of the modernization development. In this paper, which used in power system communication channel are analyzed and compared, combined with the rapid development of communication technology, put forward a kind of image monitoring system based on CDMA wireless channel. Based on the analysis of the characteristics of the CDMA structure and, fully affirmed the emerging transmission medium is applied to power system automation feasibility and broad application prospect, thus proves the system to improve the power system automation, improve the reliability and real-time performance is of great significance. CDMA network for electric power automation system provides a fast and reliable, easy extension, and easy to maintain communication mode, and the remote monitoring system based on the wireless communication, has no wiring work, reduce the network construction cost, save a lot of cost, short construction period, the expansion of sex is strong, high reliability, fast transfer rate, numerous advantages of rapidity, etc. As long as it is covered in CDMA network, image monitoring can at any time and do the real mobile monitoring.

Power system automation is heavily dependent on the reliable interconnection of power system field equipment and centralised control applications. Particularly important to achieve reliability in automated power systems is the redundant connection of field equipment controllers. Today, the fundamental redundancy management and switch-over processes are handled by the power system control applications itself. This, however, increases the complexity of the control systems and leads to an intersection of concerns. Consequently, the design and the implementation of field equipment controller redundancy is time-consuming and cost-intensive.In this paper, we propose the implementation of a redundancy virtualisation layer for power system controllers based on software-defined networking (SDN). The goal is to relieve the control applications from managing field level redundancy. Thus, our SDN approach allows to detect gateway failures and to perform transparent switch-overs. This significantly simplifies the configuration of the control application with redundant components and finally leads to more flexible and simplified redundancy design, deployment and operation. Arbitrary redundancy topologies, such as triple-controller-redundancy can be implemented without modifying the control applications.

Power system automation and communication standards are spearheading the power system transition towards a smart grid. IEC 61850 is one such standard, which is widely used for substation automation and protection. It enables real-time communication and data exchange between critical substation automation and protection devices within digital substations. However, IEC 61850 is not cyber secure. In this paper, we demonstrate the dangerous implications of not securing IEC 61850 standard. Cyber attacks may exploit the vulnerabilities of the Sampled Values (SV) and Generic Object-Oriented Substation Event (GOOSE) protocols of IEC 61850. The cyber attacks may be realised by injecting spoofed SV and GOOSE data frames into the substation communication network at the bay level. We demonstrate that such cyber attacks may lead to obstruction or tripping of multiple protective relays. Coordinated cyber attacks against the protection system in digital substations may cause generation and line disconnections, triggering cascading failures in the power grid. This may eventually result in a partial or complete blackout. The attack model, impact on system dynamics and cascading failures are veri ed experimentally through a proposed cyber-physical experimental framework that closely resembles real-world conditions within a digital substation, including Intelligent Electronic Devices (IEDs) and protection schemes. It is implemented through Hardware-in-the-Loop (HIL) simulations of commercial relays with a Real-Time Digital Simulator (RTDS).

Integrating large-capacity wind power into a power system has a great impact on the voltage stability of a power system. Especially, a fault in such a system can result in the tripping of a large amount of wind power generation or system collapse. This article studies the effect of large-capacity wind power generation on power system voltage stability under a fault condition. The adopted wind power model consists mainly of a wind turbine, drive device, asynchronous generator, and control system. The proposed analysis approach is applied to a practical power system with wind power, which is located in Gansu province in China. Through simulation and analysis, the characteristic and stability principle of an asynchronous wind generator group are recognized. A speed increase in a wind generator group is closely related to voltage drop after fault, which may cause voltage instability if they both impact each other after fault. The detailed results are presented in the article.

Amicrogrid is a combination of clusters of distributed generators connected to fulfill the requirement of dedicated load. A microgrid can be operated with standalone or grid connected mode. A microgrid when operated in standalone mode with a limited voltage and power rating is more likely prone to a serious damage due to its unpredictable faults. Load flow, voltage stability & short circuit analysis of a micro-grid is essential for both design and performance monitoring and to ensure reliable microgrid operations. The faults with a continuously varying in nature affects the normal operation of buses and so to the peripherals associated to the micro-grid. The cause and severity of such faults plays a vital role while designing protection scheme in standalone micro-grid as standalone mode has confined generation. In this paper, electrical model of a 52.3 kW Photo-voltaic based micro-grid is developed on Electrical Transient Analysis Program (ETAP) and various transient conditions such as load flow, loss of DG & short circuit analyses are performed. A detailed short circuit analysis puts light on various short circuit conditions and provides useful analysis. ETAP is the most comprehensive analysis platform for the design, simulation, operation, and automation of generation, distribution, and industrial power systems. ETAP also provides the industry leading transient analysis of power system and micro-grid so chosen for this transient analysis study. A short circuit analysis is calculated based onIEC Std. 60909 using ETAP. This paper presents a simulated model of micro-grid with actual system oriented results and analyzes responses of system during fault conditions and various contingencies.

Introduction of distributed generation, deregulation and distribution of control has brought new challenges for electric power system operation, control and automation. Traditional power system models used in reasoning tasks such as intelligent control are highly dependent on the task purpose. Thus, a model for intelligent control must represent system features, so that information from measurements can be related to possible system states and to control actions. These general modeling requirements are well understood, but it is, in general, difficult to translate them into a model because of the lack of explicit principles for model construction. Available modeling concepts for intelligent control do not assist the model builder in the selection of model content i.e. in deciding what is relevant to represent for a particular reasoning task and thereby faced with a difficult interpretation problem. In this paper, we present our work on using explicit means-ends model based reasoning about complex control situations which results in maintaining consistent perspectives and selecting appropriate control action for goal driven agents.

The growth of distributed generation or renewable generation resources and advanced information systems add uncertainties and complexity to the energy system and call for a “smart grid” solution. The mathematical models that are conventionally utilized in the energy management system usually take a long time to develop and execute and are not flexible enough to accommodate operational rules for generations (wind, solar and hydro) under varying conditions and loads. A rule-based system model would allow power system operators (who may lack experience in exploiting mathematical models and computer capabilities) to model their operations directly using their expertise, which enables the power system to make quick responses to real-time conditions. In this paper, a new rule-based system design methodology for power system automation and control is proposed. The methodology formulates the rule-based system as an optimal control problem in a feedback control architecture. The solution to the optimal control problem provides action rules for power system substation operations to achieve operator-configured preferences while minimizing cost. The proposed methodology, which integrates real-time information, optimal control, environmental constraints and human's expertise, provides a systematic tool for rule-based system design that gives more robust and realistic solutions.

High temperature superconducting (HTS) power cables are expected to be used in the future in electric ships that will have integrated power and energy systems (IPES). There have been a few studies on understanding electrical faults in power systems consisting of HTS cables; however, there are no comprehensive studies on the response of HTS cables for various types of electrical faults. We have recently initiated a research project on understanding various electrical faults in shipboard medium voltage direct current (MVDC) power systems and the duration of the fault, maximum voltage, and maximum current that the HTS cables will encounter during the fault. This paper presents investigations on the potential cable architectures being developed for MVDC power systems, and the type of faults that HTS cables will encounter in such systems. The paper will assess the relative merits of these architectures in terms of their suitability for accommodating the limitations of cryogenically cooled HTS cables and offer design suggestions for resilient power systems. Electrical and cryogenic thermal models of HTS cables that are suitable for assessing the response of HTS cables for electrical faults, as well as HTS cable designs that can endure electrical faults without catastrophic damage will also be discussed.

The transition towards a more affordable, reliable, and sustainable energy provision paradigm is one of the main 21st century challenges that humanity must overcome to protect the planet from the harmful effect caused by climate change. The concentration of CO2 in the atmosphere has been dramatically increasing since the pre-industrial era. If the increase of green-house gasses emissions continues unabated, this will bring dramatic consequences for planet Earth, compromising eventually the existence of many species, including the human race. To avoid a climate change catastrophe, the share of primary energy coming from renewable energy resources must increase from around 15% in 2015 to 65% in 2050. This energy transition can not rely solely on few successful technologies (i.e., solar photovoltaic, and wind energy), but it must count on a larger variety of technical solutions that are suitable for a wider range of renewable sources and diversity of circumstances. For instance, renewable thermal energy sources for power generation (i.e., geothermal reservoir, biomass fuel, and concentrated solar radiation), can provide a large portion of the world electricity demand in the future. However, the exploitation of a good portion of these sources strongly depends on the market success of technologies such as the Organic Rankine Cycle (ORC) power system. One of the key aspects to make ORC systems economically competitive, especially at the smaller sizes (⇡ 1 − 50 kW), is the realization of highly efficient turbomachinery components. The fluid-dynamic design of ORC turbomachinery significantly differs from the design of traditional machines (i.e., steam and gas turbines), and this is mainly due to the different thermo-physical properties and gas dynamic behavior of the organic working fluids. This means that design methods devised for standard steam and gas turbomachinery can not be used for turbomachinery operating in the Non-ideal compressible fluid dynamics (NICFD) region. Furthermore, no experimental campaigns have ever been carried out to create a body of empirical knowledge to support the design highly efficient ORC turbomachinery. As a consequence, the entire design process of ORC turbomachinery relies only on the use of advanced CFD software. The current trend is to couple CFD tools with numerical optimization techniques in order to automatically obtain optimal flow passage geometries. In particular, adjoint-based methods have clearly demonstrated to be the only optimization technique capable of tackling the multi-stage turbomachinery design problem, in which thousands of design variable must be concurrently optimized. Therefore, the research documented in this PhD dissertation aimed at extending the adjoint method in order to perform the fully-turbulent fluid-dynamic shape optimization of 3D multi-stage ORC turbomachinery. This document contains an extensive introduction, three main chapters, each documenting a building block towards the accomplishment of the main goal of this PhD project, and a final concluding chapter that summarizes all the research outcomes of this work and proposes future steps for research in this field. The first part of the thesis describes the extension of the RANS equations, the convective numerical schemes, and the viscous numerical schemes to the use of complex thermo-physical laws, so to simulate turbulent flows of components working in the NICFD thermodynamic region. The second part documents the derivation of the adjoint solver in order to resolve shape-optimization design problems for 2D single row of ORC turbomachinery. Finally, the last part reports the extension of the adjoint method to 3D multi-stage turbomachinery design.

With the progress and development of domestic power system, the automation, intelligence and informatization of power system have made great progress. However, as an important carrier of national information security and residents' electricity demand, how to ensure the safe and stable operation of power system has become a hot topic. The real-time monitoring of alarm information of power system monitoring system is the basic work of substation, converter station and monitoring center. The traditional way of listing information one by one has been difficult to meet the needs of monitoring center for a large number of substations. This paper analyzes the problems existing in the current monitoring of converter station equipment, introduces 5g high-speed wireless sensor network, optimizes the form of alarm window and abnormal information processing to ensure that the alarm information is effectively monitored.


 This paper deals with a load flow simulation of existing Dhaka Grid Circle of Bangladesh National Grid by using Power System Analysis Toolbox (PSAT) which is a free and open source software of MATLAB Simulink and Electrical Transient and Analysis Program (ETAP) software designed for simulation, operation, and automation of generation, distribution, and industrial power systems. All the data used to simulate were collected from Power Grid Company of Bangladesh (PGCB) and Load flow analysis was carried out using Newton Raphson method and simulated results were compared with PGCB Base Case Data. The network we are considering to simulate has 71 buses (400, 230 and 132 kV), 135 interconnecting lines, 32 generators, 47 loads and only 4 shunt capacitors as per the Dhaka grid circle system. Regarding the maximum demand of the load centers, total 5,525 MW load is connected in this system and the average grid generation in September, 2018 was 10,919.57 MW, though only 5988 MW of the total generation is enlisted in the Dhaka grid circle.