Showing papers by "ABB Ltd published in 2017"

Design of Solid-State Circuit Breaker-Based Protection for DC Shipboard Power Systems

Abstract: Fast increasing dc fault currents in dc shipboard distribution systems require fast dc protective devices and protection methods. Solid-state circuit breakers (SSCBs) inherently have fast protection speed and thus are proper for dc shipboard distribution protection. Based on the analysis of the fault current features in dc shipboard distribution systems, the design of the system protection employing SSCBs is discussed from the perspectives of SSCB technologies, design requirements, and protection methods. Fast speed, low cost, low loss, and optimized design are major challenges of SSCB-based dc shipboard distribution protection.

A Novel Fault Location Method and Algorithm for DC Distribution Protection

Abstract: DC fault current is contributed by various distributed energy resources in dc distribution systems. The tightly coupled dc distribution systems have relatively low line impedance values. The fault current increases fast because of the low impedance. Some converters in dc distribution systems include fault current limiting function. The controlled fault currents at different locations are very close. Thus, it is important to design a reliable and fast fault detection and location method for dc distribution systems. This paper proposes a novel local measurement-based fault location algorithm for tightly coupled dc distribution systems. The proposed fault location algorithm can estimate the equivalent inductance between a protective device and a fault in less than 1 ms. The performance of the developed protection algorithm was validated by numerical simulation and hardware tests.

Building an IoT Data Hub with Elasticsearch, Logstash and Kibana

Abstract: The goal of this publication is to describe the implementation of an Elastisearch, Logstash and Kibana (ELK) stack to process IoT data. Although, those tools were designed to be used mainly for handling large number of log data, they can be applied also to store, search and visualise other type of information - including IoT data. In order to show practical implementation of the idea, selected devices installed in thebuilding of ABB Corporate Research in Krakow has been used. In prepared system, real data generated by various subsystems in this building has been integrated into one Elasticsearch based solution for further processing. Later on, this data will be used to develop data analytics to extract and visualize meaningful insights about building operations. In addition, selected data is sent to the Azure cloud to use its abilities in big data processing and machine learning.

Distributed virtual inertia based control of multiple photovoltaic systems in autonomous microgrid

Abstract: The large inertia of a traditional power system slows down system U+02BC s frequency response but also allows decent time for controlling the system. Since an autonomous renewable microgrid usually has much smaller inertia, the control system must be very fast and accurate to fight against the small inertia and uncertainties. To reduce the demanding requirements on control, this paper proposes to increase the inertia of photovoltaic U+0028 PV U+0029 system through inertia emulation. The inertia emulation is realized by controlling the charging U+002F discharging of the direct current U+0028 DC U+0029-link capacitor over a certain range and adjusting the PV generation when it is feasible and U+002F or necessary. By well designing the inertia, the DC-link capacitor parameters and the control range, the negative impact of inertia emulation on energy efficiency can be reduced. The proposed algorithm can be integrated with distributed generation setting algorithms to improve dynamic performance and lower implementation requirements. Simulation studies demonstrate the effectiveness of the proposed solution.

Design, construction, and analysis of a large scale inner stator radial flux magnetically geared generator for wave energy conversion

Abstract: A magnetically geared machine (MGM) integrates a magnetic gear with a low torque, high speed electric machine to create a single compact high torque, low speed device with the size advantages of a mechanically geared system and the reliability of a direct drive machine. This work investigates the use of MGMs for wave energy conversion through the development of a large scale magnetically decoupled inner stator radial flux magnetically geared generator rated for 10 kW at an input speed of 30 rpm. Critical design trends are illustrated using parametric 2D and 3D finite element simulation results. Information is also provided about the prototype's mechanical structure and key magneto-mechanical design considerations, including the impact of modulator bridges and the extent of axially escaping leakage flux. The prototype's experimental stall torque of 3870 N·m represents a 99.1% match with the simulated stall torque and corresponds to volumetric and gravimetric torque densities of 82.8 kN·m/m3 and 14.5 N·m/kg, respectively. Additionally, the prototype achieves an experimental efficiency of approximately 90% over much of its operating range.

Solid state circuit breakers for shipboard distribution systems

Abstract: The increasing need for better performance, protection, and reliability in shipboard power distribution systems, and the increasing availability of power semiconductors is generating the potential for solid state circuit breakers to replace traditional electromechanical circuit breakers. This paper reviews various solid state circuit breaker topologies that are suitable for low and medium voltage shipboard system protection. Depending on the application solid state circuit breakers can have different main circuit topologies, fault detection methods, commutation methods of power semiconductor devices, and steady state operation after tripping. This paper provides recommendations on the solid state circuit breaker topologies that provides the best performance-cost tradeoff based on the application.

Fault current limiting power converters for protection of DC microgrids

Abstract: This paper presents a review of different topologies of power converters that are suitable for interfacing power sources to the dc distribution bus of a microgrid. Despite the high controllability of electronic power converters, not all converter topologies behave the same during a bus fault condition. Some topologies are able to limit fault currents, can participate in the protection scheme and can decrease the risk of catastrophic damage. Other topologies lose controllability in a situation of fault on the distribution bus and need to be protected against permanent damage by fast fuses, circuit breaker and fault current limiters. Power converters, such as back-to-back VSCs, buck-type isolated converters, Full Bridge MMCs and similar, can be controlled to limit the fault currents, coordinated with protection devices, minimize the risk of catastrophic damage of the distribution system and increase the resilience and survivability of the microgrid.

Environmental and safety aspects of AirPlus insulated GIS

Abstract: New insulation gases as alternatives to SF6 have been presented in the last years. The main focus has been on technical performance and reduced global warming potential compared with SF6 gas-insulated switchgear (GIS). Another very important aspect for customers is the environmental impact and safety in all operational situations, as well as during leaks or even internal arc failures. This study introduces a solution using AirPlus™ as an insulation gas mixture, with results of comparison tests to SF6 GIS and air-insulated switchgear.

Transformer Design Principles, Third Edition

Abstract: In the newest edition, the reader will learn the basics of transformer design, starting from fundamental principles and ending with advanced model simulations. The electrical, mechanical, and thermal considerations that go into the design of a transformer are discussed with useful design formulas, which are used to ensure that the transformer will operate without overheating and survive various stressful events, such as a lightning strike or a short circuit event. This new edition includes a section on how to correct the linear impedance boundary method for non-linear materials and a simpler method to calculate temperatures and flows in windings with directed flow cooling, using graph theory. It also includes a chapter on optimization with practical suggestions on achieving the lowest cost design with constraints.

DC power distribution: New opportunities and challenges

Abstract: The benefits offered by the DC energy distribution in different applications raised the interests towards new power architectures and apparatus. The availability of the related LV and MV apparatus and protection schemes is in fact crucial to fully exploit the opportunities opened in the energy management for the smart grid. Experimental results of testing DC circuit breakers based upon current injection and solid-state technologies are presented and their effectiveness for DC distribution protection is discussed. The possibilities opened by local measurement and communication to support the operation of DC circuit breakers for DC protection as well as the design challenges and implementation issues are investigated.

Multi-Layer Cross Domain Reasoning over Distributed Autonomous IoT Applications

Abstract: Due to the rapid advancements in the sensor technologies and IoT, we are witnessing a rapid growth in the use of sensors and relevant IoT applications. A very large number of sensors and IoT devices are in place in our surroundings which keep sensing dynamic contextual information. A true potential of the wide-spread of IoT devices can only be realized by designing and deploying a large number of smart IoT applications which can provide insights on the data collected from IoT devices and support decision making by converting raw sensor data into actionable knowledge. However, the process of getting value from sensor data streams and converting these raw sensor values into actionable knowledge requires extensive efforts from IoT application developers and domain experts. In this paper, our main aim is to propose a multi-layer cross domain reasoning framework, which can support application developers, end-users and domain experts to automatically understand relevant events and extract actionable knowledge with minimal efforts. Our framework reduces the efforts required for IoT applications development (i) by supporting automated application code generation and access mechanisms using IoTSuite, (ii) by leveraging from Machine-to-Machine Measurement (M3) framework to exploit semantic technologies and domain knowledge, and (iii) by using automated sensor discovery and complex event processing of relevant events (ACEIS Middleware) at the multiple data processing layers and different stages of the IoT application development life cycle. In the essence, our framework supports the end-users and IoT application developers to design innovative IoT applications by reducing the programming efforts, by identifying relevant events and by suggesting potential actions based on complex event processing and reasoning for cross-domain IoT applications.

Internet-of-Things and Cloud Computing for Smart Industry: A Systematic Mapping Study

Abstract: Intelligent industry and manufacturing requires obtaining relevant sensor data and process information in real-time from all components in the manufacturing value-chain. It is envisioned that smart industry is achieved by embedding connectivity into industrial products, using Cloud and Internet-of-things (IoT) to leverage intelligence and actionable knowledge for machines, autonomous collaboration among machines, and integration of products and additional value-added services. For complex industrial systems, it is important to ensure a smooth transformation towards the smart industry vision despite of the associated challenges with respect to e.g., transition from the traditional multi-layered architecture to an open structured service-oriented automation system architecture, changes of business models and strategies, legacy system migration to cloud environment, etc. The focus of this study is therefore to examine the status of the existing research on cloud computing and IoT solutions that enable this transformation towards a smart industry. We applied the systematic mapping study method to obtain an overview of the existing related research literatures that focus on smart industry, industrial automation and manufacturing perspective. We also discuss the future research areas that need to be enhanced.

A measurement method to extract the transient junction temperature profile of power semiconductors at surge conditions

Abstract: This paper presents an experimental measurement method to obtain the transient junction temperature profile of power semiconductor devices in surge current operations. Even though a few methods to estimate the device junction temperature have been reported, they are not focused on dynamic surge conditions or experimental measurements which are important for power conversion and protection equipment such as UPS, motor drives and solid state breakers. A procedure is proposed in this work to extract how the junction temperature grows in a transient surge operation with experimental proof. The procedure is based on the measurement of temperature sensitive parameter such as on-resistance of the semiconductors, and the iteration of the basic measurements to reconstruct the transient junction temperature curve. The application of the proposed method includes the calibration and verification of the thermal simulation, design and optimization, estimation of the device's surge capability, device packaging optimization for thermal design, etc.

Inrush current limiting for solid state devices using NTC resistor

Abstract: This paper proposes a passive method to limit inrush currents for solid state switching devices, such as circuit breakers, contactors, relays, and other electrical apparatuses. The method proposes to limit inrush currents with a negative temperature coefficient resistor in series connection with the power semiconductor switching device and integrated into the switching device. This new configuration permits to avoid excessive overrating of power semiconductor devices and thus to reduce the cost of solid state switching devices. In the event of an inrush current at closing of the device, the negative temperature coefficient resistor limits the current to an acceptable level. In this way, overheating and failure of power semiconductor switching devices can be avoided.

Analyzing Worst-Case Delay Performance of IEC 61850-9-2 Process Bus Networks Using Measurements and Network Calculus

Abstract: In power substation automation systems (SASs) based on IEC 61850, conventional hardwired process connections are being replaced by switched Ethernet To ensure system reliability and responsiveness, transmission of critical information required by protection and control tasks must satisfy hard delay constraints at all times Therefore, delay performance conformance should be taken into consideration during the design phase of an SAS project In this paper, we propose to study the worst-case delay performance of IEC 61850-9-2 process bus networks, which generally carry non-feedforward traffic patterns, through the combination of measurements and network-calculus-based analysis As an Ethernet switch supports dedicated interconnections between its multiple interfaces, our proposed approach converts a non-feedforward network into feedforward ones by introducing service models for its individual output interfaces instead of modeling it in its entirety with a single service model To derive practical delay bounds that can be validated against measurement results, our approach not only constructs traffic models based on the idiosyncrasies of process bus network and switched Ethernet, but also establishes service models of networking devices by taking measurements Results from our case studies of both feedforward and non-feedforward process bus networks show that the proposed combination of network calculus and measurement-based modeling generates accurate delay bounds for Ethernet-based substation communication networks (SCNs) The proposed approach can thus be adopted by designers and architects to analytically evaluate worst-case delay performance at miscellaneous stages of SAS design

On-line gas monitoring for increased transformer protection

Abstract: Transformers are vital and high cost components of the electric power system On-line monitoring is a tool that can assess the condition of these valuable assets in real time The importance of a monitored transformer and the economic consequences of a failure, provide the basis for selecting a monitor with its potential cost benefits The most basic and important transformer monitoring equipment is the on-line Dissolved Gas Analysis (DGA) monitor This paper discusses the importance of on-line DGA monitoring for power transformers, types of available sensors and various qualities to examine when choosing a monitoring device

Slotless lightweight motor for drone applications

Abstract: This paper proposes a slotless, lightweight permanent magnet (PM) motor for drone applications. This research analyzes the steps through FEA to achieve the torque speed profile required for drone applications with optimum pole count for the base speed. A comparison on slotless vs slotted stators is presented. In addition, an optimization using halbach configuration proves to give a superior design over conventional rotor designs. Finally, the analysis leads to a slotless stator with halbach PM configuration in the rotor for a 4 kW system achieving high power density, very low cogging torque and torque ripple, sinusoidal BEMF, and good system efficiency. The resulting low inductance (μH range) of the proposed machine opens up the opportunity of using wide band gap devices as the enabling technology.

Solid-state fault current limiting for DC distribution protection

Abstract: This paper discusses solid-state fault current limiting technologies. Both solid-state fault current limiters and converters can quickly limit DC fault currents and permit other protective devices to perform appropriate fault interruption and/or isolation. Different system protection strategies using solid-state fault current limiters and converters are presented and analyzed. The advantages and disadvantages of different methods are also discussed and compared.

Using Source Code Metrics and Multivariate Adaptive Regression Splines to Predict Maintainability of Service Oriented Software

Abstract: Prediction of maintainability parameter for Object-Oriented Software using source code metrics is an area that hasattracted the attention of several researchers in academia andindustry. However, maintainability prediction of Service-Orientedsoftware is a relatively unexplored area. In this work, we conductan empirical analysis on maintainability prediction of eBay webservices using several source code metrics. We consider elevendifferent types of source code metrics as input for developinga maintainability prediction model using Multivariate AdaptiveRegression Splines (MARS) method. We compare and evaluatethe performance of the maintainability prediction model withMultivariate Linear Regression (MLR) approach and SupportVector Machine (SVM). Eight different types of feature selectiontechniques have been implemented to reduce dimension andremove irrelevant features. The experiment results reveals thatthe maintainability prediction model developed using MARSmethod achieved better performance as compared to MLR andSVM methods. Experimental results also demonstrate that themodel developed by considering a selected set of source codemetrics by feature selection technique as input achieves betterresults as compared to the approach which considers all sourcecode metrics.

Cyber security – security strategy for distribution management system and security architecture considerations

Abstract: We cover some practices and methods in creating effective cyber security architectures for substation and distribution automation systems and products which are robust enough to withstand cyber-attacks and resilient enough to recover in the event of security compromise and keeping device functional and executing its core functionality even during attack. This is achieved by a defence-in-depth strategy starting from product design, a dedicated security test centre, secure system architecture, patch management and security audits. Understanding practices and processes helps in handling cyber security in a holistic manner with an explicit focus on operational performance.

Novel Large-Area Attachment for High-Temperature Power Electronics Module Application

Abstract: Soft soldering is still the standard bonding method in order to provide a large void-free joining area in power electronics module applications. Ag sintering has been proven for small-area die attach applications to increase junction temperature and reliability. In this paper, we explore silver sintering technology further for large-area high-temperature substrate bonding in order to enable full benefits of SiC power semiconductors in terms of higher junction temperature, higher power density and higher reliability.

Impedance-Based Stability Analysis of MVDC Systems Using Generator-Thyristor Units and DTC Motor Drives

Abstract: This paper develops a generalized ac impedance model for synchronous generators and then a dc impedance model for generator-thyristor systems. The impedance model of a medium voltage dc (MVdc) system is built for impedance-based stability and harmonics analysis. DC current harmonics from a high-power neutral point clamped (NPC) direct torque control (DTC) motor drive is examined. It is found that dc network resonance is a major cause of dc current harmonics amplification and propagation in MVdc systems. As a result, adding a dc side input filter can attenuate current harmonics from NPC DTC drives. Three criteria to design the dc-side filter are deduced from the impedance analysis. The effectiveness of the design criteria is tested and verified by time-domain simulations.

Real-time hardware-in-the-loop modeling for microgrid applications

Abstract: This paper describes a system for development and testing microgrid control and protection functions in a realistic controller-in-the-loop real-time simulation environment. The method presented in this paper utilizes high resolution time domain models for distributed energy resources and their primary controllers interfaced with supervisory microgrid controllers and protection relays either through communication or analog channels/digital contacts. This approach provides higher granularity for testing microgrid control function implementations as compared to pure simulation based approaches, particularly when using validated component models. It also offers significant cost savings compared to full-scale power-in-the loop laboratory test beds. The paper explains the basic real-time hardware-in-the-loop (RTHIL) setup and presents simulation results for several major use cases.

A novel ISOP current-fed modular dual-active-bridge (CF-MDAB) DC-DC converter with DC fault ride-through capability for MVDC application

Abstract: This paper proposes a novel input-series output-parallel (ISOP) current-fed modular dual-active-bridge (CF-MDAB) dc-dc converter for medium-voltage dc (MVDC) system application. The proposed converter exhibits favorite features of DAB converter such as galvanic isolation, soft-switching condition and small passive components. Compared to ISOP DAB converter, the proposed topology has direct dc current controllability, thus can achieve dc circuit breaking and fault ride-through operation. The operating principle is described, and the corresponding control system is developed to realize the power flow and balancing control. A case study of 500 kW, 20 kHz ISOP CF-MDAB is simulated for validation and downscaled experimental results will be given in full paper.

Time-Aware Test Case Execution Scheduling for Cyber-Physical Systems

Abstract: Testing cyber-physical systems involves the execution of test cases on target-machines equipped with the latest release of a software control system. When testing industrial robots, it is common that the target machines need to share some common resources, e.g., costly hardware devices, and so there is a need to schedule test case execution on the target machines, accounting for these shared resources. With a large number of such tests executed on a regular basis, this scheduling becomes difficult to manage manually. In fact, with manual test execution planning and scheduling, some robots may remain unoccupied for long periods of time and some test cases may not be executed.

Quantifying fossil fuel savings from investment in renewables and energy storage

Abstract: In communities where electricity generation depends on fossil fuel, there is a rising interest in renewable energy as the new source of electricity. In many cases, wind and solar, two dominant types of renewables, are readily accessible. However, investing in these resources is still a risky endeavor: the initial cost of such projects is still high. Moreover, because of the intermittency in wind and solar resources, grid code may require additional equipment (such as energy storage) and new controllers (monitoring, protection, and control algorithms), adding to the cost of the new plants. This paper describes a methodology to guide investment decisions in renewable energy. For each penetration level of renewable energy, the associated projects are evaluated for their benefit and cost. The benefit, defined as fossil fuel saving (the difference between the fossil fuel used before and after a renewable project is installed), can be estimated using software tools for security-constrained economic dispatch. The cost of each project can be estimated based on market and vendors' data. The resulting Benefit-Cost curve typically reveals the effect of diminishing returns: increasing the project size (more and more renewables) requires more investment, but may not produce the desired increase in fossil fuel savings. Such results can serve as a valuable guide for decision makers.

Human-robot impact model: For safety assessment of collaborative robot design

Abstract: In this research, a novel impact simulation model based on compliant contact force (CCF) modelling approach is presented. This model can simulate the physical impact between non-homogeneous and layered elastic bodies representing the robot and human body parts. The proposed CCF model is intended to be used by the robot designers to execute safety evaluation tasks during the design and development of collaborative robot systems. The main theoretical contribution from this CCF impact model is related to the formulations, which can account for the contact behavior due to the non-homogeneous nature of the impacting bodies. The relevance of the proposed impact simulation is evaluated based on a comparative analysis with other available relevant models from the literature as well as with Finite element based simulation model. Finally, the influence of various robot design parameters on the impact severity is analyzed for different impact scenarios by adopting the proposed CCF model.