Showing papers presented at "International Symposium on Industrial Electronics in 2016"

Current control of reluctance synchronous machines with online adjustment of the controller parameters

Abstract: This paper discusses nonlinear proportional-integral (PI) current control with anti-windup of reluctance synchronous machines (RSMs) for which the flux linkage maps are known (e.g. obtained by FEM analysis or measurements). Due to the nonlinear flux linkage, the current dynamics of RSMs are highly nonlinear and, so, to obtain an (almost) identical current closed-loop dynamics over the complete operation range, the controller parameters and the disturbance compensation terms must be adjusted online at each sampling instant. The model-based controller design is derived theoretically in state space. The theoretical results are illustrated and validated by simulation and measurement results.

Modeling and analysis of DC-DC SEPIC converter with coupled inductors

Abstract: Nowadays, DC/DC converters are widely used in industrial applications and renewable energy systems. A SEPIC (single-ended primary inductance converter) DC-DC converter is capable of operating in either step-up or step-down mode and commonly used in a battery charger system. This paper presents the modeling and analyzing of the SEPIC with coupled and uncoupled inductors. In this study, the state-space averaged (SSA) model is established and built in MATLAB/Simulink environment. The obtained SEPIC model was simulated for different input parameters, and results of coupled and uncoupled are compared. Moreover, the small signal model is used for linearization of the SSA model of the SEPIC with coupled and uncoupled inductors, hence the transfer function of control (duty cycle) to output voltage is formulated. Bode plots of the duty cycle to output voltage transfer functions are constructed, and the result can be used in various applications to design a closed-loop controller to regulate the output voltage.

Optimal power flow in multiterminal HVDC systems considering DC/DC converters

Abstract: This paper presents a non-linear model for the optimal power flow in multi-terminal high-voltage direct current transmission systems. The proposed methodology considers exclusively the DC side of the grid and includes branches with DC/DC converters. Losses of lines and DC/DC converters are also considered in the optimization model. A semidefinite approximation is proposed in order to obtain an unique solution for real time operation. The methodology is evaluated on a reduced version of the CIGRE B4 DC grid test system. Results demonstrate the proposed approximation is efficient and accurate compared to the non-linear model solved in GAMS.

Improving cybersecurity for Industrial Control Systems

Abstract: The vulnerability of industrial control systems (ICS) to electronic intrusion and malware has recently been well documented in both the technical and popular press. Despite significant attention and much progress over the past 15 years, threats continue to evolve about as fast as preventive solutions. This paper reviews the root causes of ICS cybersecurity vulnerabilities, looks at some common defensive measures and then discusses a new approach to ICS field device cybersecurity, the security preprocessor. This device offers advanced communications security and role-based access control for legacy ICS installations, and utilizes a verified microkernel, with proven security properties.

A review on switched reluctance machines for electric vehicles

Abstract: Nowadays, switched reluctance machines (SRM) are gaining interest in the scientific community due to the advantages they offer. The SRM offers an overall efficiency similar to an induction motor of the same rating, since the friction and windage losses are comparable. Many researches have been done on SRMs, their related systems and challenges. This paper reviews the SRM structures, their advantages and disadvantages. Various SRM topologies are studied and their merits and limits are given. Additionally, the most common control strategies for SRM drives are categorized, which is followed by a summary of the researches on challenges in torque and vibration reduction.

Microgrid cooperative distributed energy scheduling (CoDES) considering battery degradation cost

Abstract: Obtaining an optimal charging and discharging schedule of battery energy storage devices in a microgrid is essential to the economic and reliable operation of the system. The depth of discharge (DoD) is a key variable that affects the cycle life of a battery. In this paper, an energy scheduling problem is formulated for a microgrid considering battery degradation cost under different DoD scenarios. The formulated scheduling problem is solved by using the cooperative distributed energy scheduling (CoDES) algorithm in a distributed way. The operation of the CoDES algorithm is demonstrated and the economic benefit of using battery energy storage devices in a microgrid is analyzed under different DoD scenarios.

A robust, intelligent CC-CV fast charger for aging lithium batteries

Abstract: This paper proposes a robust, intelligent constant current-constant voltage (CC-CV) charger for fast charging an aging Lithium-ion battery. Increasing the charging current in the CC regime cannot guarantee the short charging time, so an optimal charging current exists in the CC-CV method. The optimal charging current changes with battery degradation, so this paper figures out a way to find the optimal charging current by applying direct current internal resistance (DCIR) tests before the CC-CV charging method. The experiment results show that the proposed charger can adjust the optimal current based on battery state-of-health (SOH). The charging time has a 6.5% improvement when it is compared to a standard CC-CV fast charger.

PCA and PLS monitoring approaches for fault detection of wastewater treatment process

Abstract: In order to produce the goods with high quality, the industrial system is becoming more complex than before. Meanwhile, the plant is suffering from high potential risks and the faults within it is difficult to be detected. Researchers have made efforts to diagnose the possible faults occurred in the system to further prevent the process from being broken down. Model-based method is proposed at the beginning and it receives effective monitoring results indeed. However, the mathematic model of the system should be known as prior, and it is challenging to achieve the goal. On the other hand, the Multivariate Statistical Process Monitoring (MSPM) does not require that people have clearly understood the process model before carrying out the diagnosis method. Two approaches based on Principal Components Analysis (PCA) and Partial Least Squares (PLS) separately are included in the framework of MSPM. This paper firstly introduces PCA and PLS techniques, including the algorithms, the test statistic, and differences between them. Then the thesis proposes Benchmark Simulation Model No.1 (BSM1), which is used to testify the efficiency of the proposed methods. Finally, the simulation is carried out and the result is reported.

Capacitance reduction in a single phase Quasi Z-Source Inverter using a hysteresis current controlled active power filter

Abstract: One of the major issues in a single phase inverter topology is the 120Hz ripple which needs large decoupling capacitors. Big bulky electrolytic capacitors can be an issue in applications where compact size and high power density are requirements such as solar converter chargers. In z source inverter systems, the design of the impedance network is critical. In single phase z source inverter systems, the z-source network can get quite bulky if the second harmonic power fluctuations are not compensated. In this paper an active power filter (APF) has been analyzed for the DC side of the Quasi Z-Source Inverter(qZSI) Topology and hysteresis current control technique has been adopted to eliminate the voltage fluctuations in the DC side of the inverter. As a result the impedance network has been designed with the values as low as three phase z-source inverter systems and the capacitor values are low enough to replace the bulky capacitors by film capacitors, which in turn increases the life and power density of such inverter systems. The other advantage of this DC side APF being the control is simpler than an AC side APF.

HTML web content extraction using paragraph tags

Abstract: With the ever expanding use of the internet to disseminate information across the world, gathering useful information from the multitude of web page styles continues to be a difficult problem. The use of computers as a tool to scrape the desired content from a web page has been around for several decades. Many methods exist to extract desired content from web pages, such as Document Object Model (DOM) trees, text density, tag ratios, visual strategies, and fuzzy algorithms. Due to the multitude of different website styles and designs, however, finding a single method to work in every case is a very difficult problem. This paper presents a novel method, Paragraph Extractor (ParEx), of clustering HTML paragraph tags and local parent headers to identify the main content within a news article. On websites that use paragraph tags to store their main news article, ParEx shows better performance than the Boilerpipe algorithm with higher F1 scores of 97.33% to 88.53%.

Semantics for smart control of building automation

Abstract: Building automation is an important part of state-of-the-art building management in order to attain most efficient operation in accordance with comfort requirements, energy consumption, or budget allowance. For this purpose, current building management systems enable communication with subjacent systems at the field and automation level by definition of mostly syntactical technology mappings. However, integration of building automation systems for management and control purposes also needs to address the semantics of these subsystems, their cooperation, and their interference. In this work, such an integration approach is presented that enables smart control of building automation resources by the use of semantic technologies. An OWL ontology is developed in order to represent and link knowledge of all relevant domains. Furthermore, an interface concept for seamless and interoperable cross-border communication in the heterogeneous building automation environment is introduced. Finally, an application scenario illustrates the functional capabilities of this approach for smart control in building management.

Comprehensive review and comparative analysis of compensation networks for Capacitive Power Transfer systems

Abstract: Contactless Capacitive Power Transfer (CPT) is one of the emerging fields in the area of wireless power transfer. The system is fairly analogues to the inductive power transfer system. The CPT systems was primarily used for low power and small distance applications due to the development of unsafe voltages across the capacitive interface. However, the use of new compensation networks have enabled the system to be used for small, medium and long distance applications. There is no literature currently available that summarizes all the compensator's available for the CPT network. This makes it extremely difficult to find the best compensator which will suit the requirement of the designer. The paper focuses on the need for compensation and analysis of the system. The results of the analysis can be applied to any of the compensator's that are discussed in the later section. A common ground is then established which would help in finding the best compensator's available. Based on the results obtained, the best compensator for various distances and power applications would be recommended.

Wearable security: Key derivation for Body Area sensor Networks based on host movement

Abstract: The Internet-of-Things relies on ad-hoc connections, which also requires an on-demand approach to the negotiation of security parameters. We propose a new approach to shared key derivation for Body Area Networks (BANs). Body area networks are quickly becoming increasingly important in the world of healthcare with wide application in the treatment and monitoring of chronic patients using on-body devices. Advancements in the field will result in quicker response times in emergency situations, and detect complications in patients at a much earlier stage potentially saving many lives. In this paper, we have used motion sensors instead of the more common physiological signals that need physical access to the body, like electrocardiograms (ECG), to pair devices and secure communication in Body Area Networks. Our method considers the acceleration of the devices that needs to communicate. These measurements tend to be similar as devices are deployed on the same host body, which means that these could be used to derive shared keys. We show that these measurements results in derived keys that are unpredictable and exhibit significant difference with previous keys. This is an improvement over existing schemes where keys vary for different hosts but tend to be similar over time.

Accurate Thevenin's circuit-based battery model parameter identification

Abstract: Batteries are becoming the main energy storage devices in following decades. Highly accurate battery models are needed to fulfill accurate controlling and monitoring purpose. For real-time operations, the calculation complexity of the battery model is an issue. Thevenin's circuit model is a tradeoff between fast calculation and accuracy. The model uses resistor and RC pairs to capture the dynamic of terminal voltage. Even though there are few components in the model, to accurately identify those components value is a difficult question. In this paper, an algorithm to separate effective data and ineffective data is proposed by comparing the condition number. This algorithm can help identify correct parameters for future model-based battery monitoring and controlling.

Control for Quasi Two-Level PWM Operation of Modular Multilevel Converter

Abstract: Quasi Two-Level PWM Operation of the Modular Multilevel Converter reduces the amount of energy to be stored in the modules significantly. While keeping many of the advantages of modular multilevel topologies (modularity, scalability, small voltage steps and redundancy), the multilevel operation of course is lost. This paper presents a possible control for a three-phase inverter. The control is verified by simulation.

Studying crawling effect in Line-Start Synchronous Reluctance Motors (LS-SynRM)

Abstract: Line starting capability of Synchronous Reluctance Motors (SynRM) is a crucial challenge in their design that if solved, could lead to a valuable category of motors. In this paper, the so-called crawling effect as a potential problem in Line-Start Synchronous Reluctance Motors (LS-SynRM) is analyzed. Two interfering scenarios on LS-SynRM start-up are introduced and one of them is treated in detail by constructing the asynchronous model of the motor. In the third section, a definition of this phenomenon is given utilizing a sample cage configuration. The LS-SynRM model and characteristics are compared with that of a reference induction motor (IM) in all sections of this work to convey a better perception of successful and unsuccessful synchronization consequences to the reader. Several important post effects of crawling on motor performance are discussed in the rest of the paper to evaluate how it would influence the motor operation. All simulations have been performed using Finite Element Analysis (FEA).

Analysis framework for evaluating PLC software: An application of Semantic Web technologies

Abstract: Control software in the automated production systems domain is becoming increasingly complex. As a consequence, appropriate methods to improve control software quality need to be identified. Although sophisticated frameworks and tools for software quality improvement exist in the computer science domain, support for industrial control software development is still limited. As a first step towards addressing this issue, this paper proposes an analysis framework that aims at evaluating control software by means of Semantic Web technologies.

Harmonic elimination of multilevel inverters by moth-flame optimization algorithm

Abstract: This paper solves harmonic elimination problem, and minimizes total harmonic distortion by a recently developed heuristics: moth-flame optimization method. 5th and 7th order harmonics are eliminated for a seven level cascaded multilevel inverter, and 5th, 7th, 11th and 13th order harmonics are eliminated for an eleven level cascaded multilevel inverter. Simulation results of a seven level cascaded multilevel inverter and an eleven level cascaded multilevel inverter are provided for different levels of modulation indexes. The simulation results show that moth-flame optimization model solves the harmonic elimination problem, total harmonic distortion minimization problem efficiently.

Efficient finite control set-model predictive control for grid-connected photovoltaic inverters

Abstract: Finite control set-model predictive control (FCS-MPC) is a promising control scheme for power converters/inverters and electric drives due to its flexibility and simplicity. Using all the possible voltage vectors (VVs) generated by the inverter (7 VVs for 2-level inverter) and a discrete-time model of the system, the future behavior of the inverter can be predicted. Then, a certain cost function is employed for selecting the best switching action that will be applied in the next sampling interval (7 evaluations of the cost function are required). Accordingly, the main disadvantage of the traditional FCS-MPC scheme is the heavy calculation load. In this paper, an efficient FCS-MPC method for a grid-connected photovoltaic (PV) inverter is proposed in order to reduce the calculation burden of the traditional FCS-MPC. Based on the required reference current, the reference voltage vector (VV) is directly calculated. Then the sector where this reference VV is located is identified from its angle. Consequently, the cost function is evaluated only three times to obtain the optimal switching vector. The performance of the proposed efficient FCS-MPC is compared with the traditional FCS-MPC and voltage oriented control (VOC) schemes by simulation results for all operation conditions.

Hardware-in-the-loop simulation of FPGA-based state estimators for electric vehicle batteries

Abstract: This paper describes a hardware-in-the-loop (HiL) simulation platform specifically designed to test state estimators for Li-ion batteries in electric vehicle applications. Two promising estimators, the Mix algorithm combined with the moving window least squares and the dual extended Kalman filter, are implemented in hardware on a field-programmable gate array (FPGA) and evaluated using the developed HiL platform. The simulation results show the effectiveness of using FPGAs for hardware acceleration of battery state estimators and the importance of their assessment under different operating conditions, i.e., driving schedules, which can be simulated by the HiL platform.

Modelling approaches for an asymmetrical six-phase machine

Abstract: With currently available power electronic devices, the power range of a single three-phase power converter is limited well below the power ratings foreseen for remote offshore wind turbines. A solution is to use multiphase systems. By connecting each of the converters to one three-phase winding in the stator of the machine, a multiphase conversion system is obtained allowing to exploit its fault tolerance. In multiphase machines, the basic idea of the model transformations is the same as in the three-phase case, but, due to the increase in the dimension of the system, it introduces additional degrees of freedom. This work at first compares the two widely used modelling approaches regarding physical interpretation of the subspaces, harmonic mapping and representation of asymmetries applied to an asymmetrical six-phase machine. It further introduces an alternative transformation that is aimed at situations where power sharing between three-phase windings is desired and characterises its behaviour using the same figures of merit as for the existing transformations.

Knowledge-driven service orchestration engine for flexible information acquisition in industrial cyber-physical systems

Abstract: Cyber-physical systems attract attentions from many domains including industrial automation recently. Cyber-physical production system or industrial cyber-physical system is considered as key to achieve collaborative automation systems. The service-oriented architecture is often linked with industrial cyber-physical systems to lift flexibility and interoperability. By adopting service-oriented architecture in industrial cyber-physical systems, a new way of information acquisition is enabled by dynamically composing services according to requests. In this paper, a knowledge-driven service orchestration engine is introduced for process requests from human or devices and collect information automatically by assembling services dynamically. The service composition process is described using a room lighting system example. Tools required by the service orchestration engine and future development plan are provided.

Probabilistic foreground detector with camouflage detection for sterile zone monitoring

Abstract: Probabilistic modeling of background is extensively used for foreground detection in computer vision. Gaussian Mixture Models (GMM) is famous choice for detecting foreground in video sequences owing to ability of adapting background variation. However, GMM is prone to camouflage effect i.e. foreground object and background having same pixel intensity. This paper proposes foreground detector based on GMM with camouflage detection for sterile zone monitoring. Before modeling background, decision module based on third order image moments (skewness) is implemented to decide whether certain frame needs image enhancement. Then, histogram equalization (HE) is applied on such frame to differentiate between foreground object and background and then modeled using GMM. Morphological operations are incorporated on foreground mask to improve final results. The proposed method tested on i-LIDS dataset for sterile zone monitoring outperforms conventional GMM and detects camouflage object in all video sequences.

Control of a single-phase grid inverter with on-line inductance identification

Abstract: This paper proposes a novel on-line inductance identification method to account for inductance saturation in current controller design for single-phase grid-connected inverter with single inductor filter. The predictive control method with delay compensation is used which has wide bandwidth and reaches steady state within one switching period in current control loop. A multiple-sampling method is developed for instantaneous current feedback, which can get average current even in DCM operation and low duty ratio conditions. An on-line inductance identification technique is proposed to compensate the model inductance parameter variation and stabilize the transient disturbances. Simulation and experiment results have been carried out to verify the results.

Predictive data analysis driven multi-agent system approach for electrical micro grids management

Abstract: Micro grid represents an emergent paradigm to address the challenges of recent smart electrical grid visions, where several small-scale and distributed electrical units cooperate to achieve higher levels of energy self-sustainability, by reducing the main grid dependence. Nevertheless, the realization of this paradigm requires advanced intelligent approaches that are able to effectively manage the micro grid infrastructure and its elements. Multi-agent systems provide a suitable framework to support the development of such systems, where autonomous agents endowed with predictive data analysis capabilities take advantage of the large amount of data produced to predict the renewable energy production and consumption. In this context, this paper presents a predictive data analysis driven multi-agent system for the management of micro grids renewable energy production. The proposed approach was applied to an experimental case study, considering different predictive algorithms and data sources for the short and midterm forecasting of the production of wind and photovoltaic energy-based units.

Simplified mathematical modelling of phase-shift controlled series-series compensated inductive power transfer system

Abstract: In this paper small-signal model of a symmetrical clamped mode controlled series-series compensated inductive power transfer (IPT) system has been derived using the extended describing function (EDF) method. The derived model has duty cycle, input voltage and switching frequency as control variables and an output voltage as an output variable. A voltage controller has been designed for symmetrical clamped mode control using the SISO Design Tool from MATLAB®. To test the designed controller, a prototype of the series-series compensated IPT system has been developed in lab. Simulation results and experimental results are presented in this paper for the validation of the designed controller.

IoT-based integration of IEC 61131 industrial automation systems: The case of UML4IoT

Abstract: Internet of Things (IoT) plays a key role in the new generation of industrial automation systems (IASs). Evolving IoT standards if effectively used may address many challenges in the development of IASs. However, the use of the IoT and the REST architectural paradigm that IoT is based on, is not an easy task for the automation engineer. In this paper, a model driven system engineering process is adopted for IASs and it is extended to exploit IoT standardization efforts in IEC 61131 based system. IoT is considered as an enabling technology for the integration of cyber-physical and cyber components of the system and humans, bringing into the industrial automation domain the benefits of this technology. A UML profile for IoT is exploited to automate the generation process of the IoTwrapper, i.e., the software layer that is required on top of the IEC 61131 cyber part of the cyber-physical component to expose its functionality to the modern IoT IAS environment. A prototype implementation and performance measurements prove the feasibility of the presented approach.

Semantic models for physical processes in CPS at the example of occupant thermal comfort

Abstract: The increasing availability of sensor data leads to new integration problems in Cyber Physical Systems (CPS). In this paper we present an automatable approach to model CPS systems with common Linear, Time-Invariant processes. We show how this approach can be used to model the thermal processes in a room as well as complex measurements like thermal comfort. We demonstrate our approach for a real building with numerous connected sensors and show how our semantic framework allows us to detect and diagnose abnormal thermal comfort. This can lead to not only an increase of occupant well-being but also to a reduction of energy use. Given that buildings consume 40% of the world's energy use we therefore also make a contribution towards global sustainability.

Analytical calculation of air-gap magnetic field distribution in transverse-flux machines

Abstract: Analytical methods are useful tools in the design of rotating electric machines because the simulation times tend to be low and they provide a good insight However, in the analysis of non-traditional machines, like the transverse-flux machine (TFM), the most common approach is to use finite element analysis (FEA) In this paper we show how to use the complex permeance (CP) methodology to obtain the magnetic field distribution on the air-gap of a homopolar TFM produced by the stator windings The properties of the CP function are based on conformal mapping theory Also, we propose an algorithm to estimate the parameters of the CP function after evaluating the function in a set of randomly generated number of points, which reduces the computation time significantly The proposed methodology is applied to a single-sided TFM showing that the results are consistent with FEA calculations

Modeling of residential centralized and baseboard space heating systems

Abstract: The Smart grid scenario in the local side imposes a responsible utilization of energy consumption with the participative behavior of the end-users. Utilities offer nowadays many alternatives to their clients in order to prevent peak power demand that greatly affects the electricity supplier when the grid capacity is exceeded. The residential energy profiles in Nordic countries have a particular behavior concerning their energy consumption; in fact, most of the energy is employed in water heater systems and space heating systems during winter time. This paper focuses on the modeling and simulation of space heating systems commonly employed in Canadian residences. In this study, the centralized and baseboard systems models are compared in order to provide a better comprehension of technical and operational aspects. The impact of thermostat types and their setup applied to the two heating systems is evaluated in terms of the peak power and energy consumption. Simulation results demonstrate the potential of the proposed modeling approach for multi-residential energy and power analysis.