In the Nordic power network, the existence of poorly damped low-frequency inter-area oscillations (LFIOs) has long affected stability constraints, and thereby, limited power transfer capacity. Adequate damping of inter-area modes is, thus, necessary to secure system operation and ensure system reliability while increasing power transfers. Power system stabilizers (PSS) is a prevalent means to enhance the damping of such modes. With the advent of phasor measurement units (PMUs), it is expected that wide-area damping control (WADC), that is, PSS control using wide-area measurements obtained from PMUs, would effectively improve damping performance in the Nordic grid, as well as other synchronous interconnected systems. Numerous research has investigated one ``branch'' of the problem, that is, PSS design using various control schemes. Before addressing the issue of controller design, it is important to focus on developing proper understanding of the ``root'' of the problem: system-wide oscillations, their nature, behavior and consequences. This understanding must provide new insight on the use of PMUs for feedback control of LFIOs. The aim of this thesis is, therefore, to lay important concepts necessary for the study of power system small signal stability analysis that considers the availability of synchrophasors as a solid foundation for further development and implementation of ideas and related applications. Particularly in this study, the focus is on the application addressed damping controller design and implementation. After a literature review on the important elements for wide-area damping control (WADC), the thesis continues with classical small signal stability analysis of an equivalent Nordic model; namely, the KTH-NORDIC32 which is used as a test system throughout the thesis. The system's inter-area oscillations are identified and a sensitivity analysis of the network variables directly measured by synchrophasors is evaluated. The concept of network modeshapes, which is used to relate the dynamical behavior of power systems to the features of inter-area modes, is elaborated. Furthermore, this network modeshape concept is used to determine dominant inter-area oscillation paths, the passageways containing the highest content of the inter-area oscillations. The dominant inter-area paths are illustrated with the test system. The degree of persistence of dominant paths in the study system is determined through contingency studies. The properties of the dominant paths are used to construct feedback signals as input to the PSS. Finally, to exemplify the use of the dominant inter-area path concept for damping control, the constructed feedback signals are implemented in a PSS modulating the AVR error signal of a generator on an equivalent two-area model, and compared with that of conventional speed signals.

New innovations, technologies, ideas and businesses are driving the realisation of the Internet of Things (IoT) vision. As with many other fields in technology comes competing protocols and standards, ranging from modulation schema used for transmitting data to security standards used to ensure safe operation and the privacy needs for all involved entities. This thesis looks into one of the competing modulation schema and network protocols for IoT applications: the LoRaWAN protocol. The main contribution of this thesis is a datadriven empirical study that helps verify theoretically obtained results from other authors. Our results also suggest that as long as other signals on the same frequency band uses different modulation techniques (or just other parameters for the same modulation technique), then only the signal to noise ratio is affected without introducing collisions. This affects the scalability and overall practical distance covered by a LoRaWAN. Our general conclusion is that the LoRaWAN as a technology/protocol has its disadvantages, mainly how heavily different traffic profiles may affect the scalability of it and a general lack of hard quality of service guarantees.

Indiana University-Purdue University Indianapolis (IUPUI) / The thesis extends the work done in [1] [2] by Rovnyak, et al. where the authors have described about transient event prediction and response based one shot control using decision trees trained and tested in a 176 bus model of WECC power system network. This thesis contains results from rigorous simulations performed to measure robustness of the existing one shot control subjected to missing PMU's data ranging from 0-10%. We can divide the thesis into two parts in which the first part includes understanding of the work done in [2] using another set of one-shot control combinations labelled as CC2 and the second part includes measuring their robustness while assuming missing PMU's data. Previous work from [2] involves use of decision trees for event detection based on different indices to classify a contingency as a 'Fault' or 'No fault' and another set of decision trees that decides either to actuate 'Control' or 'No control'. The actuation of control here means application of one-shot control combination to possibly bring the system to a new equilibrium point which would otherwise attain loss of synchronism. The work done in [2] also includes assessing performance of the one shot control without event detection. The thesis is organized as follows- Chapter 1 of the thesis highlights the effect of missing PMUs' data in a power system network and the need to address them appropriately. It also provides a general idea of transient stability and response of a transient fault in a power system. Chapter 2 forms the foundation of the thesis as it describes the work done in [1] [2] in detail. It describes the power system model used, contingencies set, and different indices used for decision trees. It also describes about the one shot control combination (CC1) deduced by Rovnyak, et.al. of which performance is later tested in this thesis assuming different missing data scenarios. In addition to CC1, the chapter also describes another set of control combination (CC2) whose performance is also tested assuming the same missing data scenarios. This chapter also explains about the control methodology used in [2]. Finally the performance metrics of the DTs are explained at the end of the chapter. These are the same performance metrics used in [2] to measure the robustness of the one shot control. Chapter 2 is thus more a literature review of previous work plus inclusion of few simulation results obtained from CC2 using exactly the same model and same control methodology. Chapter 3 describes different techniques of handling missing data from PMUs most of which have been used in and referred from different previous papers. Finally Chapter 4 presents the results and analysis of the simulation. The thesis is wrapped up explaining future enhancements and room for improvements.

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Nowadays it is more clear that the Internet of things (IoT) is not a transient trend but a completely new industry. The internet of things has the capability to enhance current industries (Industry 4.0), as well as to help protecting the environment and people. The latter is the case with the system developed and described in this thesis. The possibilities that IoT brings are due to the interconnection of heterogeneous embedded devices to the internet. This thesis focus on LPWANs (Low Power Wide Area Networks), which is a new set of technologies specifically design for the needs of IoT devices.Due to the recent deploy of NB-IoT (Narrow Band IoT) networks it has become more difficult to know what LPWAN is best for a certain application. Thus, the first half of this thesis involves the comparative study of NB-IoT and LoRaWAN LPWANs. This comparison required an in depth study of each technology, specially on the physical and datalink layers. The comparison briefly displays the main characteristics of each technology and explain the main conclusions in a concise manner. The second part of the thesis describes the development of a GNSS tracker. This tracker will be used on train wagons carrying goods that are dangerous for people and the environment. This thesis report describes the different steps taken, from the requirement specification to the partial development of the software.

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Recent large-scale blackouts revealed that power systems around the world are far from the stability and reliability requirement as they suppose to be. The post-event analysis clarifies that one major reason of the interconnection blackout is lack of wide area information. Frequency dynamics is one of the most important parameters of an electrical power system. In order to understand power system dynamics effectively, accurately measured wide-area frequency is needed. The idea of building an Internet based real-time GPS synchronized wide area Frequency Monitoring Network (FNET) was proposed to provide the imperative dynamic information for the large-scale power grids and the implementation of FNET has made the synchronized observations of the entire US power network possible for the first time. The FNET system consists of Frequency Disturbance Recorders (FDR), which work as the sensor devices to measure the real-time frequency at 110V single-phase power outlets, and an Information Management System (IMS) to work as a central server to process the frequency data. The device comparison between FDR and commercial PMU (Phasor Measurement Unit) demonstrate the advantage of FNET. The web visualization tools make the frequency data available for the authorized users to browse through Internet. The research work addresses some preliminary observations and analyses with the field-measured frequency information from FNET. The original algorithms based on the frequency response characteristic are designed to process event detection, localization and unbalanced power estimation during frequency disturbances. The analysis of historical cases illustrate that these algorithms can be employed in real-time level to provide early alarm of abnormal frequency change to the system operator. The further application is to develop an adaptive under frequency load shedding scheme with the processed information feed in to prevent further frequency decline in power systems after disturbances causing dangerous imbalance between the load and generation. / Ph. D.

Frequency dynamics is one of the most important signals of a power system, and it is an indicator of imbalance between generation and load in the system. The Internet-based real-time GPS-synchronized wide-area Frequency Monitoring Network (FNET) was proposed to provide imperative frequency dynamics information for a variety of system-wide monitoring, analysis and control applications. The implementation of FNET has for the first time made the synchronized observation of the entire U.S. power network possible with very little cost. The FNET is comprised of many Frequency Disturbance Recorders (FDR) geographically dispersed throughout the U.S. and an Information Management System (IMS), currently located at Virginia Tech. The FDR works as a sensor, which performs local measurements and transmits calculations of frequency, voltage magnitude and voltage angle to the remote servers via the Internet. Compared with its commercial counterpart Phasor Measurement Unit (PMU), FDR provides less expensive version for networked high-resolution real-time synchronized. The improved single phase algorithm in the FDRs made it possible to measure at 110V level which is much more challenging than PMUs due to the noise involved at this level. This research work presents the challenges and issues of both software and hardware design for the novel measurement device FDR, which is one of the devices with the highest dynamic precision for power system frequency measurement. The DFT-based Phasor Angle Analysis algorithm has been improved to make sure the high-resolution measuring FDRs are installed at residential voltage outlets, instead of substation high-voltage inputs. An embedded 12-channel timing GPS receiver has been integrated to provide an accurate timing synchronization signal, UTC time stamp, and unit location. This research work also addresses the harmonics, voltage swing and other noise components' impacts on the measurement results, and the optimized design of filters and a coherent sampling scheme to reduce or eliminate those impacts. The verification test results show that the frequency measurement accuracy of the FDR is within +/-0.0005Hz, and the time synchronization error is within +/-500ns with suitable GPS antenna installation. The preliminary research results show the measurement accuracy and real-time performance of the FDR are satisfactory for a variety of FNET applications, such as disturbance identification and event location triangulation. / Ph. D.