A critical analysis of research potential, challenges and future directives in industrial wireless sensor networks

In recent years, Industrial Wireless Sensor Networks (IWSNs) have emerged as an important research theme with applications spanning a wide range of industries including automation, monitoring, process control, feedback systems and automotive. Wide scope of IWSNs applications ranging from small production units, large oil and gas industries to nuclear fission control, enables a fast-paced research in this field. Though IWSNs offer advantages of low cost, flexibility, scalability, self-healing, easy deployment and reformation, yet they pose certain limitations on available potential and introduce challenges on multiple fronts due to their susceptibility to highly complex and uncertain industrial environments. In this paper a detailed discussion on design objectives, challenges and solutions, for IWSNs, are presented. A careful evaluation of industrial systems, deadlines and possible hazards in industrial atmosphere are discussed. The paper also presents a thorough review of the existing standards and industrial protocols and gives a critical evaluation of potential of these standards and protocols along with a detailed discussion on available hardware platforms, specific industrial energy harvesting techniques and their capabilities. The paper lists main service providers for IWSNs solutions and gives insight of future trends and research gaps in the field of IWSNs

Remote Cell Growth Sensing Using Self-Sustained Bio-Oscillations

A smart sensor system for cell culture real-time supervision is proposed, allowing for a significant reduction in human effort applied to this type of assay. The approach converts the cell culture under test into a suitable “biological” oscillator. The system enables the remote acquisition and management of the “biological” oscillation signals through a secure web interface. The indirectly observed biological properties are cell growth and cell number, which are straightforwardly related to the measured bio-oscillation signal parameters, i.e., frequency and amplitude. The sensor extracts the information without complex circuitry for acquisition and measurement, taking advantage of the microcontroller features. A discrete prototype for sensing and remote monitoring is presented along with the experimental results obtained from the performed measurements, achieving the expected performance and outcomes

Analysis of an On-Line Stability Monitoring Approach for DC Microgrid Power Converters

An online approach to evaluate and monitor the stability margins of dc microgrid power converters is presented in this paper. The discussed online stability monitoring technique is based on the Middlebrook's loop-gain measurement technique, adapted to the digitally controlled power converters. In this approach, a perturbation is injected into a specific digital control loop of the converter and after measuring the loop gain, its crossover frequency and phase margin are continuously evaluated and monitored. The complete analytical derivation of the model, as well as detailed design aspects, are reported. In addition, the presence of multiple power converters connected to the same dc bus, all having the stability monitoring unit, is also investigated. An experimental microgrid prototype is implemented and considered to validate the theoretical analysis and simulation results, and to evaluate the effectiveness of the digital implementation of the technique for different control loops. The obtained results confirm the expected performance of the stability monitoring tool in steady-state and transient operating conditions. The proposed method can be extended to generic control loops in power converters operating in dc microgrids

A Wireless, Multi-Channel Printed Capacitive Strain Gauge System for Structural Health Monitoring

Structural health monitoring of soft structural textiles plays a key role within the space industry to ensure the safety and integrity of space habitats, parachutes, and decelerator systems. Strain monitoring could be an effective means to evaluate structural integrity, but conventional monitoring systems are not suitable because they are intended for large, rigid structures. To overcome the limitations of rigid sensors, we recently proposed using printed capacitive strain gauges (CSGs) on flexible substrates to monitor the structural health of soft structure materials. Here, we present a strategy and implementation of a wireless, multi-channel readout system for distributed monitoring of soft structural textiles with printed CSGs. The system is comprised of localized sensor motes and a wireless Bluetooth hub. The sensor mote employs a relaxation oscillator frontend to convert capacitance to frequency with a high dynamic range using only three interface wires per mote. The mote’s high dynamic range ensures compatibility with various gauge designs and accommodates significant process variation associated with printed gauges. Each hub enables users to read 8 channels of data wirelessly at a sampling rate of 100Hz and can be scaled to higher channel counts through the use of additional hubs. The sensor motes and wireless hub are miniaturized to accommodate flexible substrates, such as a Kevlar strap. The system is tested and exhibits excellent linearity and dynamic range

Advanced sensors technology survey

This project assesses the state-of-the-art in advanced or 'smart' sensors technology for NASA Life Sciences research applications with an emphasis on those sensors with potential applications on the space station freedom (SSF). The objectives are: (1) to conduct literature reviews on relevant advanced sensor technology; (2) to interview various scientists and engineers in industry, academia, and government who are knowledgeable on this topic; (3) to provide viewpoints and opinions regarding the potential applications of this technology on the SSF; and (4) to provide summary charts of relevant technologies and centers where these technologies are being developed

Evaluation of Battery Performance in MMC based BESS

abstract: Li-ion batteries are being used on a large scale varying from consumer electronics to electric vehicles. The key to efficient use of batteries is implementing a well-developed battery management system. Also, there is an opportunity for research for improving the battery performance in terms of size and capacity. For all this it is imperative to develop Li-ion cell model that replicate the performance of a physical cell unit. This report discusses a dual polarization cell model and a battery management system implemented to control the operation of the battery. The Li-ion cell is modelled, and the performance is observed in PLECS environment. The main aspect of this report studies the viability of Li-ion battery application in Battery Energy Storage System (BESS) in Modular multilevel converter (MMC). MMC-based BESS is a promising solution for grid-level battery energy storage to accelerate utilization and integration of intermittent renewable energy resources, i.e., solar and wind energy. When the battery units are directly integrated in submodules (SMs) without dc-dc interfaced converters, this configuration provides highest system efficiency and lowest cost. However, the lifetime of battery will be affected by the low-frequency components contained in arm currents, which has not been thoroughly investigated. This paper investigates impact of various low-frequency arm-current ripples on lifetime of Li-ion battery cells and evaluate performance of battery charging and discharging in an MMC-BESS without dc-dc interfaced converters.Dissertation/ThesisMasters Thesis Electrical Engineering 201

Modeling, Analyses and Assessment of Microgrids Considering High Renewable Energy Penetration

Microgrids are receiving attention due to the increasing need to integrate distributed generations and to ensure power quality and provide energy surety to the customers. Since renewables need to be in the mix for energy surety, a high renewable-energy penetrated microgrid is analyzed in this paper. The standard IEEE 34 bus distribution feeder is adapted and managed as a microgrid by adding distributed generation and load profiles. The 25kV system parameters are scaled down to 12kV and renewable sources including solar PV and wind turbines, an energy storage system, and a natural gas generator have been added to the 34-bus system. The distribution generations (DG) and renewables are modeled in detail using PSCAD software and practical constraints of the components are considered. The droop control and autonomous control for microgrid normal operation in islanded mode and grid-tied mode have been proposed and studied. A novel comprehensive supervisory control scheme has been defined to manage the microgrid transition from or to the bulk grid, and to minimize the transients on voltage and frequency. Detailed analyses for islanding, reconnection, and black start are presented for various conditions. The proposed control techniques accept inputs from local measurements and supervisory controls in order to manage the system voltage and frequency. The monitoring of the microgrid for measuring power quality and control requirements for DGs and storage are modeled. The power quality issues are discussed and indexes are calculated. A novel probabilistic assessment of microgrid reliability has been proposed. At last, several extended researches are presented. An experimental system has been built which includes three 250kW inverters emulating natural gas generator, energy storage, and renewable source. The simulation and experimental results are provided which verifies the analytical presentation of the hardware and control algorithms

Telecommunications for a deregulated power industry

Telecommunication plays a very important role in the effective monitoring and control of the power grid. Deregulation of the US power industry has enabled utilities to explore various communication options and advanced technologies. Utilities are increasingly investing in distributed resources, dynamic real-time monitoring, automated meter reading, and value added services like home energy management systems and broadband access for its customers. Telecommunication options like power line communications (PLC) and satellites are fast replacing legacy telephone and microwave systems in the US.;The objective of this thesis is to study the communication options that are available for utilities today. Phasor measurement units (PMUs) are analyzed in detail and communication delays due to the use of PMUs in wide area measurement systems (WAMS) are also studied. The highlight of this thesis is a close look at the characteristics of the power line channel by presenting a power line channel model and the use of digital modulation techniques like SS and OFDM, which help overcome the effects of such a hostile medium of communication. (Abstract shortened by UMI.)

Electrical Optimization of a Plug-In Hybrid Electric Vehicle

Hybrid electric vehicles electrification and optimization is a prominent part of today’s automotive industry. GM and the Department of Energy challenge 16 universities across North America to redesign a Chevrolet Camaro into a hybrid electric vehicle. This thesis will address how Embry Riddle Aeronautical University’s EcoCAR team electrified and optimized the vehicle. The objective of the thesis is to optimize the electric portion of the vehicle, particularly the low voltage circuitry. Prior work is discussed in detail on the vehicle communication bus, building the power distribution unit and the approach the electrical team took when building the electric portion of the vehicle. Simulations were done based on manufacturer data and bench tests to create an ideal model. Data was collected from the vehicle and compared to the ideal model to determine errors in the electrical system. An emphasis was placed on critical and high power components to simplify the simulation model. The issues found were alleviated by conducting research, using research analysis, physically changing the system or by implementing control strategies. Most of the issues came from the power distribution unit and implementation techniques such as grounding. The MOSFETs within the power distribution unit was not fully turning on and off, and which was due to a slow RC time constant occurring on the gate of the transistors. By replacing the resistors, this issue was mitigated. Every problem found was properly mitigated to an acceptable industry or research standard

Towards the integration of modern power systems into a cyber–physical framework

The cyber–physical system (CPS) architecture provides a novel framework for analyzing and expanding research and innovation results that are essential in managing, controlling and operating complex, large scale, industrial systems under a holistic insight. Power systems constitute such characteristically large industrial structures. The main challenge in deploying a power system as a CPS lies on how to combine and incorporate multi-disciplinary, core, and advanced technologies into the specific for this case, social, environmental, economic and engineering aspects. In order to substantially contribute towards this target, in this paper, a specific CPS scheme that clearly describes how a dedicated cyber layer is deployed to manage and interact with comprehensive multiple physical layers, like those found in a large-scale modern power system architecture, is proposed. In particular, the measurement, communication, computation, control mechanisms, and tools installed at different hierarchical frames that are required to consider and modulate the social/environmental necessities, as well as the electricity market management, the regulation of the electric grid, and the power injection/absorption of the controlled main devices and distributed energy resources, are all incorporated in a common CPS framework. Furthermore, a methodology for investigating and analyzing the dynamics of different levels of the CPS architecture (including physical devices, electricity and communication networks to market, and environmental and social mechanisms) is provided together with the necessary modelling tools and assumptions made in order to close the loop between the physical and the cyber layers. An example of a real-world industrial micro-grid that describes the main aspects of the proposed CPS-based design for modern electricity grids is also presented at the end of the paper to further explain and visualize the proposed framework