Energy-Aware System-Level Design of Cyber-Physical Systems

Cyber-Physical Systems (CPSs) are heterogeneous systems in which one or several computational cores interact with the physical environment. This interaction is typically performed through electromechanical elements such as sensors and actuators. Many CPSs operate as part of a network and some of them present a constrained energy budget (for example, they are battery powered). Examples of energy constrained CPSs could be a mobile robot, the nodes that compose a Body Area Network or a pacemaker. The heterogeneity present in the composition of CPSs together with the constrained energy availability makes these systems challenging to design. A way to tackle both complexity and costs is the application of abstract modelling and simulation. This thesis proposed the application of modelling at the system level, taking energy consumption in the different kinds of subsystems into consideration. By adopting this cross disciplinary approach to energy consumption it is possible to decrease it effectively. The results of this thesis are a number of modelling guidelines and tool improvements to support this kind of holistic analysis, covering energy consumption in electromechanical, computation and communication subsystems. From a methodological point of view these have been framed within a V-lifecycle. Finally, this approach has been demonstrated on two case studies from the medical domain enabling the exploration of alternative systems architectures and producing energy consumption estimates to conduct trade-off analysis

TidalSim Senior Project Report

Throughout the course of this project, our team helped the Cal Poly Biological Sciences department refine an intertidal zone simulator. The aim of this device is to allow any marine biologist to easily simulate a vast range of tidal zones in order to test animal behaviors within these zones. Another goal of this project is to make each simulation tank independent from the others by using a single microcontroller to handle all inputs and outputs of the system as well as logging all relevant data. The current system is set up so that a separate microcontroller handles dissolved oxygen and food dosing for all four tanks. One program controller per tank will make experiment setup more straightforward and thus was main goal of the project. Another goal was to make experiment setup data (tide transitions, temps, DO etc) input all in one file in Excel. The current system has some experiment data input through Excel and some that needs to be compiled in the code. This forces the scientists that use the simulator to be familiar with the development software and also introduces the risk of bugs being created accidentally. Our process to reach these goals and objectives has been documented in order to replicate the system in the future

Evaluating Internal and External Data Points in Long-term Periodical Testing with Protection Relays

A protection relay is a part of the electrical network intended to protect the distribution network and react in case of abnormal situations. The protection relay can be electromechanical, static, microprocessor-based, or digital, also known as numerical. The numerical protection relay is the newest type of protection relays, which uses a digital signal processor. With the modernization of protection relays, various failures inside the protection relays are nowadays becoming more challenging to detect. Therefore, new test methods need to be developed to detect protection relay’s failures and to test the functionality of protection relays. Continuous testing, quality assurance, and development of protection relay’s testing methods will reduce the failures may occur in protection relays. The purpose of this study is to reduce the failure situations of protection relays and to focus on ensuring and improving the quality of protection relays through their continuously expanding lifetime by performing a new test method, long-term testing, as a part of long-term test system. This study is carried out in collaboration with ABB Oy that is a major global technology company with operations in over 100 countries that specializes in automation and electrification. The first objective of this study is to conduct long-term testing with a protection relay called REX640 and to automate the entire testing process, which includes collecting, storing, and analyzing data programmatically. In this study data will be collected from internal and external data points of REX640. The research aims to discover the relevant data in long-term periodical testing with protection relays to evaluate the prediction of protection relay failures. To discover the relevant data, the first research question is defined as follow: What data is relevant in long-term periodical testing with protection relays? A proper method should be discovered to collect the relevant data. The second objective of this study is to discover a method to evaluate, store, and analyze the collected protection relay data. This will allow protection relay failures to be detected. To find the proper method, the second research question is defined as follow: Which method will be used to collect the relevant data? The interviews, literature review, and automated test environment developed in this study allowed finding answers to the research questions. As a result, the study identified the relevant data in long-term periodical testing and a proper method to collect the identified relevant data. The relevant data and the discovered method will allow identifying the defects may occur in the protection relay and evaluating the predictability of protection relay failures with long-term periodical testing before a major disruption occurs in the distribution network.Suojarele on sähköverkon osa, jonka tarkoituksena on suojata jakeluverkkoa ja reagoida poikkeustilanteissa. Suojarele voi olla sähkömekaaninen, staattinen, mikroprosessoripohjainen tai digitaalinen eli numeerinen. Numeerinen suojarele on uusin suojareletyyppi, jossa käytetään digitaalista signaaliprosessoria. Suojareleet kehittyvät nopeata vauhtia ja niiden nykyaikaistumisen myötä suojareleiden sisällä olevien erilaisten vikojen havaitseminen on nykyään entistä haastavampaa. Tämän vuoksi on kehitettävä uusia testausmenetelmiä suojareleiden sisäisten vikojen havaitsemiseksi sekä niiden toimivuuden testaamiseksi. Suojareleiden jatkuva testaus, laadunvarmistus ja kehittäminen vähentävät suojareleissä esiintyvien vikojen mahdollisuutta. Tutkimuksen tarkoituksena on vähentää suojareleiden vikatilanteita ja keskittyä varmistamaan ja parantamaan suojareleiden laatua niiden jatkuvasti pidentyvän käyttöiän aikana suorittamalla uutta testausmenetelmää, pitkäaikaistestausta osana pitkäaikaistes-tausjärjestelmää. Tämä tutkimus toteutetaan yhteistyössä ABB Oy:n kanssa. ABB on merkittävä maailmanlaajuinen teknologiayritys, jolla on toimintaa yli 100 maassa ja joka on erikoistunut automaatioon ja sähköistämiseen. Tutkimuksen yksi tavoite on suorittaa pitkäaikaista jaksottaista testausta ABB:n REX640-nimiselle suojareleelle ja automatisoida ohjelmallisesti kokonaista testausprosessia, johon sisältyy datan kerääminen, tallentaminen ja analysointi. Tutkimuksessa kerätään dataa REX640:n sisä- ja ulkopuolelta. Tutkimuksessa on selvitettävä pitkäaikaisen testauksen aikana asiaankuuluvaa dataa, jolla saadaan arvioitua suojareleen hajoamisen ennustamista. Asiaankuuluvan datan selvittämiseksi määriteltiin ensimmäinen tutkimuskysymys seuraavasti: Mikä data on relevantti pitkäaikaisessa jaksottaisessa testauksessa suojareleiden kanssa? Relevantin datan löytämiseksi, on selvitettävä menetelmä, jonka avulla voidaan kerätä kyseistä dataa. Näin ollen, tutkimuksen toinen tavoite on löytää menetelmä, jonka avulla arvioidaan, tallennettaan sekä analysoidaan suojareleestä kerättävää dataa. Sopivan menetelmän löytämiseksi määriteltiin toinen tutkimuskysymys seuraavasti: Mitä metodia tullaan käyttämään relevantin datan keräämiseksi? Tutkimuksessa kehitetyt haastattelut, kirjallisuuskatsaus, vaatimukset sekä automatisoitu testiympäristö auttoivat löytämään vastauksia tutkimuskysymyksiin. Tuloksena selvitettiin pitkäaikaiselle jaksottaiselle testaukselle relevanttia dataa sekä sopivaa metodia havaitun relevantin datan keräämiseksi. Relevantin datan sekä kehitetyn metodin avulla on mahdollisuus tunnistaa suojareleissä ilmeneviä vikoja sekä arvioida suojareleiden vikojen ennustettavuutta pitkäaikaisen jaksottaisen testauksen avulla ennen kuin jakeluverkossa tapahtuu merkittäviä häiriöitä

Tools for modelling and simulating the Smart Grid

The Smart Grid (SG) is a Cyber-Physical System (CPS) considered a critical infrastructure divided into cyber (software) and physical (hardware) counterparts that complement each other. It is responsible for timely power provision wrapped by Information and Communication Technologies (ICT) for handling bi-directional energy flows in electric power grids. Enacting control and performance over the massive infrastructure of the SG requires convenient analysis methods. Modelling and simulation (M&S) is a performance evaluation technique used to study virtually any system by testing designs and artificially creating 'what-if' scenarios for system reasoning and advanced analysis. M&S avoids stressing the actual physical infrastructure and systems in production by addressing the problem in a purely computational perspective. Present work compiles a non-exhaustive list of tools for M&S of interest when tackling SG capabilities. Our contribution is to delineate available options for modellers when considering power systems in combination with ICT. We also show the auxiliary tools and details of most relevant solutions pointing out major features and combinations over the years

Novel performance evaluation of information and communication technologies to enable wide area monitoring systems for enhanced transmission network operation

This thesis was submitted for the award of Doctor of Philosophy and was awarded by Brunel University London.The penetration of renewable energy sources has increased significantly in recent years due to the ongoing depletion of conventional resources and the transition to a low carbon energy system. Renewable energy sources such as wind energy are highly intermittent and unpredictable in nature, which makes the operation of the power grid more dynamic and therefore more complex. In order to operate the power system reliably under such conditions, Phasor Measurement Units (PMUs) through the use of satellite technology can offer a state-of-the-art Wide Area Monitoring System (WAMS) for improving power system monitoring, control and protection. They can improve the operation by providing highly precise and synchronised measurements near to real-time with higher frequency and accuracy. In order to achieve such objectives, a high-speed and reliable communications infrastructure is required to transfer time-critical PMU data from remote locations to the control centre. The signals measured by PMUs are transmitted across Local and Wide Area Networks, where they may encounter excessive delays. Signal delays can have a disruptive effect and make applications at best inefficient and at worse ineffective. The main research contribution of this thesis is the performance evaluation of communication infrastructures for WAMS. The evaluation begins from inside substations and continues over wide areas from substations to control centre. Through laboratory-based investigations and simulations, the performance of communications infrastructure in a typical power system substation has been analysed. In addition, the performance evaluation of WAMS communications infrastructure has been presented. In the modelling and analysis, an existing WAMS as installed on the GB transmission system has been considered. The actual PMU packets as received at the Phasor Data Concentrator (PDC) were captured for latency analysis. A novel algorithmic procedure has been developed and implemented to automate the large-scale latency calculations. Furthermore, the internal delays of PMUs have been investigated, determined and analysed. Subsequently, the WAMS has been simulated and detailed comparisons have been performed between the simulated model results and WAMS performance data captured from the actual WAMS. The validated WAMS model has been used for analysing possible future developments as well as to test newly proposed mechanisms, protocols, etc. in order to improve the communications infrastructure performance

Vehicle automation software development using software-only simulation

Automatic driving and driver assistance systems are gaining attraction in the automotive industry. Their development is not an easy task and requires enormous amounts of testing and validation. However, conducting all testing with a real car is expensive and ineffcient. A possible solution to streamline testing is simulation, especially software-only simulation. In software-only simulation, everything is simulated using just software. It does not require any specialized hard ware making it cheaper and easier to establish and scale up the number of testing environments. The goal of this thesis was to study how a software-only simulation environment could be built using readily available open-source components. A simulator environment based on an open-source driving simulator, CARLA, was built, and an example application was developed and integrated into it using Robot Operating System 2 (ROS2). The example application, Carlabot, supports manual driving with a gamepad and utilizes a LiDAR sensor to implement a simple collision avoider, which slows down or stops the car if something is detected in front of the car. The process of setting up a CARLA simulator environment using predefned assets, such as vehicle and world model, proved to be straightforward, and integrating a simple example application was fairly uncomplicated. However, using the environment for real product development would require customizing at least the assets. Software-only simulation brings benefts to the software development of automatic vehicles. It allows testing on a scale that is not viable using just real hardware, and it enables using test automation already in integration testing. Software-only simulation supports agile software development, where testing begins early, already during the development

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