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Showing papers presented at "International Symposium on Industrial Electronics in 2011"


Proceedings ArticleDOI
27 Jun 2011
TL;DR: In this paper, a new medium voltage multilevel multistring configuration is introduced based on a three-phase cascaded H-bridge (CHB) converter and multiple string dc-dc converters.
Abstract: Large scale grid connected photovoltaic (PV) energy conversion systems have reached the megawatt level. This imposes new challenges on existing grid interface converter topologies and opens new opportunities to be explored. In this paper a new medium voltage multilevel-multistring configuration is introduced based on a three-phase cascaded H-bridge (CHB) converter and multiple string dc-dc converters. The proposed configuration enables a large increase of the total capacity of the PV system, while improving power quality and efficiency. The converter structure is very flexible and modular since it decouples the grid converter from the PV string converter, which allows to accomplish independent control goals. The main challenge of the proposed configuration is to handle the inherent power imbalances that occur not only between the different cells of one phase of the converter but also between the three phases. The control strategy to deal with these imbalances is also introduced in this paper. Simulation results of a 7-level CHB for a multistring PV system are presented to validate the proposed topology and control method.

218 citations


Proceedings ArticleDOI
27 Jun 2011
TL;DR: The advantages and disadvantages of the two types of neural network architectures are analyzed and compared based on four different examples and indicate approaches to be taken relative to the network model selection for practical applications.
Abstract: The paper presents the properties of two types of neural networks: traditional neural networks and radial basis function (RBF) networks, both of which are considered as universal approximators. In this paper, the advantages and disadvantages of the two types of neural network architectures are analyzed and compared based on four different examples. The comparison results indicate approaches to be taken relative to the network model selection for practical applications.

127 citations


Proceedings ArticleDOI
27 Jun 2011
TL;DR: The main trends and future challenges of electrical networks embedded in “more electrical aircraft” especially in the fields of industrial electronics and energy conversion are described, including reversible and hybrid HVDC networks including new storage devices.
Abstract: This paper describes the main trends and future challenges of electrical networks embedded in “more electrical aircraft” especially in the fields of industrial electronics and energy conversion. In the first part, the current context and new standards are put forward, emphasizing the main evolutions on aircraft architectures, from AC fixed frequency networks, variable frequency to “Bleedless” architectures. The main characteristics of more electrical aircraft are discussed, especially in terms of power management rationalization, maintenance, health monitoring capacity, etc. The second part deals with the new trends and challenges of “more and more” electrical aircraft linked with power integration and new architecture with HVDC standard. Recent methodological orientations towards “Integrated Optimal Design” are discussed with representative examples. Finally, new trends towards reversible and hybrid HVDC networks including new storage devices are also emphasized.

125 citations


Proceedings ArticleDOI
27 Jun 2011
TL;DR: In this article, the authors present a careful evaluation among the most usual MPPT (Maximum Power Point Tracking) techniques, doing meaningful comparisons with respect to the amount of energy extracted from the photovoltaic (PV) panel, PV voltage ripple, dynamic response and use of sensors.
Abstract: This paper presents a careful evaluation among the most usual MPPT (Maximum Power Point Tracking) techniques, doing meaningful comparisons with respect to the amount of energy extracted from the photovoltaic (PV) panel, PV voltage ripple, dynamic response and use of sensors. Firstly, the MPPT and boost converter models were implemented via MatLab/Simulink®, and after a DC to DC boost converter, digitally controlled, was implemented and connected to an Agilent Solar Array simulator, in order to validate the simulation results. The algorithms are digitally developed and the main experimental results are also presented from the implemented prototype. Furthermore, the experimental dynamic results and the computed tracking factors are presented.

81 citations


Proceedings ArticleDOI
27 Jun 2011
TL;DR: A survey on the most popular modeling approaches for pneumatic muscle actuators can be found in this paper, where the authors analyze the PMA operation from a mathematical modeling perspective, present their merits and drawbacks of the most common PMAs, and establish the fundamental basis for developing industrial applications and conducting research in this field.
Abstract: The aim of this article is to provide a survey on the most popular modeling approaches for Pneumatic Muscle Actuators (PMAs). PMAs are highly non-linear pneumatic actuators where their elongation is proportional to the interval pressure. During the last decade, there has been an increase in the industrial and scientific utilization of PMAs, due to their advantages such as high strength and small weight, while various types of PMAs with different technical characteristics have been appeared in the literature. This article will: a) analyze the PMA's operation from a mathematical modeling perspective, b) present their merits and drawbacks of the most common PMAs, and c) establish the fundamental basis for developing industrial applications and conducting research in this field.

68 citations


Proceedings ArticleDOI
27 Jun 2011
TL;DR: A model of brushless DC motor considering behavior of the motor during commutation, with development of simple mathematical model of the BLDC motor with sinusoidal and trapezoidal waveforms of back-EMF is proposed.
Abstract: The paper proposes a model of brushless DC motor considering behavior of the motor during commutation. The torque characteristic of BLDC motor presents a very important factor in design of the BLDC motor drive system, so it is necessary to predict the precise value of torque, which is determined by the waveforms of back-EMF. After development of simple mathematical model of the BLDC motor with sinusoidal and trapezoidal waveforms of back-EMF the motor is simulated in the MATLAB/Simulink environment. Based on analysis of the time responses a comparison study of results of both BLDC motor types is presented in Graphical User Interface of MATLAB environment.

62 citations


Proceedings ArticleDOI
27 Jun 2011
TL;DR: This paper proposes a generalized dynamic model of the modular multilevel converter, which is valid for single-phase or three-phase loads and for DC or single- phase source and an analysis of the converter model applied to circulating currents and simulations results are presented.
Abstract: This paper proposes a generalized dynamic model of the modular multilevel converter, which is valid for single-phase or three-phase loads and for DC or single-phase source. The proposed model is simple and easy to simulate, it gives a powerful tool to analyze the entire converter including the circulating currents and simplify the controller design. An analysis of the converter model applied to circulating currents and simulations results are presented.

58 citations


Proceedings ArticleDOI
27 Jun 2011
TL;DR: A Brain-Computer Interface (BCI) based on the Steady-State Visual Evoked Potential (SSVEP) that can discriminate four classes once per second is presented, which allows to use this BCI to command a robotic wheelchair efficiently.
Abstract: This work presents a Brain-Computer Interface (BCI) based on the Steady-State Visual Evoked Potential (SSVEP) that can discriminate four classes once per second. A statistical test is used to extract the evoked response and a decision tree is used to discriminate the stimulus frequency. Designed according such approach, volunteers were capable to online operate a BCI with hit rates varying from 60% to 100%. Moreover, one of the volunteers could guide a robotic wheelchair through an indoor environment using such BCI. As an additional feature, such BCI incorporates a visual feedback, which is essential for improving the performance of the whole system. All of this aspects allow to use this BCI to command a robotic wheelchair efficiently.

56 citations


Proceedings ArticleDOI
27 Jun 2011
TL;DR: In this article, the trade-off between power-to-weight ratio (W/kg) and efficiency of a 100kW airborne wind turbine with a power kite flying at high speed perpendicular to the wind is investigated.
Abstract: Airborne Wind Turbines (AWT) represent a radically new and fascinating concept for future harnessing of wind power. This concept consists of realizing only the blades of a conventional wind turbine (CWT) in the form of a power kite flying at high speed perpendicular to the wind. On the kite are mounted a turbine, an electrical generator and a power electronics converter. The electric power generated is transmitted via a medium voltage cable to the ground. Because of the high flight speed of the power kite, several times the actual wind speed, only a very small swept area of the turbine is required according to Betz's Law and/or a turbine of low weight for the generation of a given electric power. Moreover, because of the high turbine rotational speed, no gear transmission is necessary and the size of the generator is also reduced. For takeoff and landing of the power kite, the turbines act as propellers and the generators as motors, i.e. electric power is supplied so that the system can be maneuvered like a helicopter. In the present work the configuration of power electronics converters for the implementation of a 100kW AWT is considered. The major aspect here is the trade-off between power-to-weight ratio (W/kg) and efficiency. The dependence of cable weight and cable losses on the voltage level of power transmission is investigated, and a comparison made of low voltage (LV) and medium voltage (MV) versions of generators. Furthermore, the interdependence of the weight and efficiency of a bidirectional Dual Active Bridge dc-dc converter for coupling the rectified output voltage of a LV generator to the MV cable is discussed. Based on this, the concept offering the best possible compromise of weight and efficiency in the power electronics system is selected and a model of the control behavior is derived for both power flow directions. A control structure is then proposed and dimensioned. Furthermore, questions of electromagnetic compatibility and electrical safety are treated. In conclusion, the essential results of the work are summarized and an outlook on future research is given. To enable the reader to make simplified calculations and a comparison of a CWT with an AWT, the aerodynamic fundamentals of both systems are summarized in highly simplified form in an Appendix, and numerical values are given for the 100kW system discussed in this work.

54 citations


Proceedings ArticleDOI
27 Jun 2011
TL;DR: In this paper, a three-phase and bi-directional contactless and contactless power transfer (IPT) system for high power V2G systems is proposed. But the proposed system uses a threephase track, which is coupled to a three phase pick-up through weak magnetic coupling.
Abstract: Contactless and bi-directional power transfer is preferable for applications such as electric vehicles (EVs) and vehicle-to-grid (V2G) systems. This paper presents a new three-phase and bi-directional IPT system that is suitable for rapid charging of EVs or high power V2G systems. The proposed system uses a three-phase track, which is coupled to a three-phase pick-up through weak magnetic coupling. Both track and pick-up are var compensated through an inductor-capacitor-inductor (LCL) resonant circuit and driven by reversible rectifiers. A mathematical model is presented to show that power transfer from the track (primary) side to the pick-up side in both directions can be controlled through either magnitude or relative phase angle of the voltages generated by reversible rectifiers. The viability of the proposed concept is demonstrated using simulations, and results suggest that the three-phase IPT system is suitable for high power applications and is superior in performance to its single-phase counterpart.

51 citations


Proceedings ArticleDOI
27 Jun 2011
TL;DR: This paper presents an efficient implementation of inverse tangent or arctangent function using look-up table with 101-points, and shows that the accuracy of the proposed method is better than the reported approximation techniques.
Abstract: Inverse tangent or arctangent function has many applications, for example, in estimating the phase angle of complex number utilized in electrical ac circuit analysis, power systems analysis, etc. Therefore, fast and accurate computation of the arctangent function is of great importance. Implementation of the arctan or atan2 using series expansions is accurate when computational cost is not an issue. However, for embedded applications such implementations cannot be used. As alternative, different approximations are proposed. In this paper, we present an efficient implementation using look-up table with 101-points. The accuracy is then increased by linear interpolation. The arctangent computation is extended to four quadrant operation using particular properties of arctan. The proposed scheme is implemented in a 60MHz microcontroller platform, typical for embedded applications. Comparative evaluations show that the accuracy of the proposed method is better than the reported approximation techniques. The time consumption of the proposed method is significantly less than that of the library function of the same microcontroller platform.

Proceedings ArticleDOI
27 Jun 2011
TL;DR: This paper proposes a new high-power-factor control method applicable for a single-phase to three-phase power converter without an electrolytic capacitor that regulates the inverter output power.
Abstract: This paper proposes a new high-power-factor control method applicable for a single-phase to three-phase power converter without an electrolytic capacitor. This converter consists of a single-phase diode rectifier, a small film capacitor at the DC-link, a voltage source three-phase inverter, and an interior permanent magnet (IPM) synchronous motor. In this system, the inverter regulates both the velocity of the IPM motor and the input-current waveform. In order to obtain a unity power factor, this paper proposes a new control method that regulates the inverter output power. An inverter output-power controller is placed between a speed controller and a q-axis current controller. The inverter power is regulated by a PI controller. The superior performance of the proposed method is demonstrated experimentally.

Proceedings ArticleDOI
27 Jun 2011
TL;DR: In this article, a series resonant compensation circuit is applied assuring zero-current switching condition for insulated-gate bipolar transistor, and the analytical expression of the dc voltage gain, current gain as well as efficiency is presented and discussed.
Abstract: Bi-directional battery charger based on an inductive coupled contactless energy transfer system is presented in this work. To minimize total losses of the system, a series resonant compensation circuit is applied assuring zero-current switching condition for insulated-gate bipolar transistor. The analytical expression of the dc voltage gain, current gain as well as efficiency is presented and discussed. The resonant frequency is adjusted by an integral control method witch guarantees very fast and stable operation. Some simulation and experimental results illustrating the operation of the developed 25-kW laboratory prototype are given.

Proceedings ArticleDOI
27 Jun 2011
TL;DR: In this article, the analysis and photometric comparison between different systems concepts for public lighting, hence the solid state lighting (SSL) employing LED luminaires with electronic drivers and the conventional high pressure sodium (HPS) lamp based lumininaires along with electromagnetic ballasts, is presented.
Abstract: This work deals with the analysis and photometric comparison between different systems concepts for public lighting, hence the solid state lighting (SSL) employing LED luminaires with electronic drivers and the conventional high pressure sodium (HPS) lamp based luminaires along with electromagnetic ballasts. The study and comparison raise question on the relative perception of the human eye to different light sources with different spectral distributions, devoting special attention to low luminance conditions (scotopic) such as those present on public roadway lighting. Different LED-based luminaires are tested, in the lab and in loco. Photometric data of a SSL system being currently installed for the replacement of current HPS luminaires at the School of Engineering of the Federal University of Juiz de Fora are provided for the analysis and comparison.

Proceedings ArticleDOI
27 Jun 2011
TL;DR: In this paper, the authors address the problem of load-shaving in smart homes in view of improving energy efficiency in Smart Grids and propose an architecture of home power management systems, allowing the separation of domestic power load control from grid dynamics.
Abstract: This paper addresses the problem of load-shaving in Smart Homes in view of improving energy efficiency in Smart Grids. An architecture of home power management systems, allowing the separation of domestic power load control from grid dynamics, is introduced. In this framework, the operation of appliances is modeled as a finite state machine which enables the implementation of online scheduling borrowed from the techniques developed in real-time computing systems. A scheduling algorithm is developed for peak-load shaving and the simulation results confirm the effectiveness and the efficiency of the proposed approach.

Proceedings ArticleDOI
27 Jun 2011
TL;DR: In this paper, a Model Predictive Control (MPC) strategy for a Voltage Source Inverter (VSI) used in a three-phase Uninterruptible Power Supply (UPS) for critical loads is presented.
Abstract: This work presents a Model Predictive Control (MPC) strategy for a Voltage Source Inverter (VSI) used in a three-phase Uninterruptible Power Supply (UPS) for critical loads. An MPC using continuous variables is proposed for solving this problem and the output of the controller is used as the reference voltage to be generated by a PWM modulator. The solution of this unconstrained MPC gives rise to an explicit solution that can be computed beforehand, allowing the prediction horizon to be easily extended. Therefore, the effect of the length of the prediction horizon over the system performance is also evaluated in the paper. This study addresses how this parameter should be chosen to minimize the error between the actual and the desired output voltage. The proposed control strategy has been tested on a simulated model of a UPS supplying a three-phase resistor load. This model has been developed using MATLAB/Simulink with PSIM software. The simulation results show that proposed continuous MPC controller achieves high performance and high degree of robustness.

Proceedings ArticleDOI
27 Jun 2011
TL;DR: In this article, the authors present three different approaches to simulate the photovoltaic (PV) module behavior under any combination of solar irradiation and ambient temperature, one of them is chosen because of its good accuracy and relatively low computational time.
Abstract: This paper refers into various ways in simulation the Photovoltaic (PV) module behaviour under any combination of solar irradiation and ambient temperature. There are three different approaches presented here briefly and one of them is chosen because of its good accuracy and relatively low computational time. After the decision of the proper model, a process which is called parameter extraction is going to take place in order to fully determine the unknowns of the model and therefore be able to simulate it. Last but not least the results and the verification process are going to take place in order to validate the proper function of the model using widely used simulation software and the manufacturer's datasheet.

Proceedings ArticleDOI
27 Jun 2011
TL;DR: In this paper, the authors present an overview of the different aspects of lifetime modeling of high power IGBTs in wind power applications and present a wind turbine reliability survey results in order to gain an insight into wind turbine subassembly failure rates and associated downtimes.
Abstract: The wind power industry is continuously developing bringing to the market larger and larger wind turbines. Nowadays reliability is more of a concern than in the past especially for the offshore wind turbines since the access to offshore wind turbines in case of failures is both costly and difficult. Lifetime modeling of future large wind turbines is needed in order to make reliability predictions about these new wind turbines early in the design phase. By doing reliability prediction in the design phase the manufacturer can ensure that the new wind turbines will live long enough. This paper represents an overview of the different aspects of lifetime modeling of high power IGBTs in wind power applications. In the beginning, wind turbine reliability survey results are briefly reviewed in order to gain an insight into wind turbine subassembly failure rates and associated downtimes. After that the most common high power IGBT failure mechanisms and lifetime prediction models are reviewed in more detail.

Proceedings ArticleDOI
27 Jun 2011
TL;DR: In this article, the authors used the work day schedule as day-type classifier and evaluated the most popular short-term load forecasting (STLF) systems in the literature, namely ARIMA (autoregressive integrated moving average) time series and Neural networks (NN), together with an Autoregressive Model and a Bayesian network (BN), concluding that the autoregressive time series outperforms its counterparts and suffices to fulfil the addressed requirements.
Abstract: Short-term load forecasting (STLF) has become an essential tool in the electricity sector. It has been classically object of vast research since energy load prediction is known to be non-linear. In a previous work, we focused on non-residential building STLF, an special case of STLF where weather has negligible influence on the load. Now we tackle more modern buildings in which the temperature does alter its energy consumption. This is, we address here fully-HVAC (Heating, Ventilating, and Air Conditioning) ones. Still, in this problem domain, the forecasting method selected must be simple, without tedious trial-and-error configuring or parametrising procedures, work with scarce (or any) training data and be able to predict an evolving demand curve. Following our preceding research, we have avoided the inherent non-linearity by using the work day schedule as day-type classifier. We have evaluated the most popular STLF systems in the literature, namely ARIMA (autoregressive integrated moving average) time series and Neural networks (NN), together with an Autoregressive Model (AR) time series and a Bayesian network (BN), concluding that the autoregressive time series outperforms its counterparts and suffices to fulfil the addressed requirements, even in a 6 day-ahead horizon.

Proceedings ArticleDOI
27 Jun 2011
TL;DR: In this paper, a Model Predictive Controller (MPC) for attitude maneuvers of an Unmanned Vertical Take Off and Landing (VTOL) Tilt-Rotor vehicle, flying in its helicopter mode is presented.
Abstract: The design of a Model Predictive Controller (MPC) for attitude maneuvers of an Unmanned Vertical Take Off and Landing (VTOL) Tilt-Rotor vehicle, flying in its helicopter mode is the subject of this article. Tilt-Rotor air vehicles combine the flight envelopes of: a)fixed wing aircrafts, and b) rotorcrafts, leading to systems with advanced flight characteristics. However, the highly nonlinear and underactuated dynamics of these systems, necessitate the design of advanced control schemes to achieve a satisfactory control performance. In the proposed control design approach, the Tilt-Rotor's nonlinear dynamics are linearized in various operating points, resulting in a set of multiple piecewise affine models that describe its helicopter's flying mode. The corresponding novel MP-controller is designed for set-point maneuvers taking into account the arbitrary switchings between the linear models as well as the constraints on the actuators, while extended simulation studies indicate the high overall efficiency of the proposed MPC scheme.

Proceedings ArticleDOI
27 Jun 2011
TL;DR: In this article, a control algorithm for fault-tolerant converters suitable for micro-grids is presented. But the authors do not consider the effect of fault tolerance on the performance of the converter.
Abstract: The penetration of Distributed Generation (DG) in power systems is deeply changing the existing distribution networks which is becoming a very sophisticated and complex systems incorporating both active (generators) and passive systems (distribution systems, converters and loads). The necessary simplification can be obtained dealing with small networks, namely Micro-Grids, reproducing, in a smaller scale, the structure and the problems of large networks including production, transmission and distribution of the electrical energy. In order to achieve an adequate level of reliability, fault-tolerant operations of micro-grids become very important. This result can be achieved only using power converters with fault-tolerance capabilities. Therefore, this paper, presents a control algorithm for fault tolerant converters suitable for micro-grids. After describing the model of the power converter reformulated in terms of healthy leg binary variable, the paper shows how this control preserves power quality when the converter works in the linear range. The effectiveness of the proposed approach is shown through computer simulations.

Proceedings ArticleDOI
27 Jun 2011
TL;DR: In this paper, a DC-link voltage MPC is proposed to calculate the required active power reference based on the output power and the energy stored in the DC link capacitor, and simulation results show a good dynamic response and a zero steady state error.
Abstract: Model predictive control (MPC) has been successfully applied to several power converters topologies, mainly because of the finite set of inputs which are given by the available switching states of these devices. However, MPC could not directly control the DC-link voltage in active-front-end(AFE) rectifiers, because they feature a non minimum phase behavior that produces an initial inverse dynamic and mislead the optimization stage selecting a wrong switching state. To avoid this effect, the DC-link voltage is usually controlled using a linear PI controller and an inner current or power control loop. However, the linear controller is difficult to design and presents a restricted dynamic behavior. In this paper, a DC-link voltage MPC is proposed. The proposed controller calculates the required active power reference based on the output power and the energy stored in the DC-link capacitor. Simulation results shows a good dynamic response and a zero steady state error.

Proceedings ArticleDOI
27 Jun 2011
TL;DR: In this paper, a five-level diode-clamped PWM inverter for a medium-voltage motor drive without regenerative braking is described, which is equipped with a specially designed circuit that plays an important role in achieving voltage balancing of four split dc capacitors connected in series at the dc input terminals of the inverter.
Abstract: This paper describes a five-level diode-clamped PWM inverter intended for a medium-voltage motor drive without regenerative braking. It is equipped with a specially-designed circuit that plays an important role in achieving voltage balancing of the four split dc capacitors connected in series at the dc input terminals of the inverter. The voltage-balancing circuit frees the inverter to concentrate on the motor control. Then, this paper has an intensive discussion on the modular multilevel cascade converter (MMCC) family that are characterized by the modular structure of either bridge cell or chopper cell. The four family members are compared from various points of view, along with applications of two promising members to a medium-voltage battery energy storage system and a medium-voltage motor drives for energy savings.

Proceedings ArticleDOI
27 Jun 2011
TL;DR: A shunt active filter which eliminates current harmonics and compensates the reactive power of the load and a modified version of the p-q theory is proposed, and simulation results are presented and discussed showing the advantages of fuzzy logic theory in the dc bus voltage control and current control.
Abstract: This paper presents a shunt active filter which eliminates current harmonics and compensates the reactive power of the load. The majority of shunt active power filter control methods which have been presented require a complex and sophisticated mathematical model, especially for the tuning of the PI controllers. To simplify and improve the shunt active filter control system, fuzzy logic theory is applied. In this paper, by the way of controlling the capacitor voltage of the dc bus a fuzzy logic algorithm is implemented. One such algorithm is also implemented to control the output current of the inverter. The performance of the capacitor voltage fuzzy logic control system was investigated, and the improvement of the dynamic response of the fuzzy controller compared to the conventional PI controller became evident. For the reduction of the grid current THDi index, a fuzzy logic hysteresis current controller is investigated. In order to improve the performance of shunt active filter under non ideal grid voltages, a modified version of the p-q theory is proposed. The simulation results are presented and discussed showing the advantages of fuzzy logic theory in the dc bus voltage control and current control.

Proceedings ArticleDOI
27 Jun 2011
TL;DR: In this article, several promising multilevel converter solutions for 10 MW wind turbines using permanent magnet synchronous generators are proposed, designed and compared both with one-stage gear box drive and direct drive systems.
Abstract: Several promising multilevel converter solutions for 10 MW wind turbines using permanent magnet synchronous generators are proposed, designed and compared both with one-stage gear-box drive and direct drive systems. The current and loss distributions, as well as the utilization of power devices in each converter are analyzed based on simulation results. Finally, the total loss and efficiency comparison are given. It is concluded that five-level and three-level H-bridge topologies show higher efficiency either in the power conversion or in the device utilization compared to the three-level Neutral-Point-Clamped topology with both the direct-drive and one-stage gear box drive systems.

Proceedings ArticleDOI
27 Jun 2011
TL;DR: This converter enjoys all the features of modular multilevel converters (M2C) such as operation independent of load power factor and modulation index, and can be extended to high number of levels without capacitor voltage balancing problem.
Abstract: This paper proposes an improved version of conventional flying capacitor multilevel converter known as active flying capacitor converter. The proposed converter replaces the clamping capacitor of the three-level flying capacitor converter by number of series connected half or full bridge cells, and uses these active cells to generate multilevel voltage waveform at converter output. Additionally, this converter enjoys all the features of modular multilevel converters (M2C) such as operation independent of load power factor and modulation index, and can be extended to high number of levels without capacitor voltage balancing problem. Also, it requires reduced number of capacitor to generate the same number of voltage level per phase as M2C; therefore it may have small footprint.

Proceedings ArticleDOI
27 Jun 2011
TL;DR: In this article, an improved technique for insulated-gate bipolar transistors (IGBTs) open-circuit fault diagnoses in voltage source inverter (VSI) fed induction motors is presented.
Abstract: This paper deals with an improved technique for insulated-gate bipolar transistors (IGBTs) open-circuit fault diagnoses in voltage source inverter (VSI) fed induction motors. The extraction of the fault information is based on the combining of the switching pattern and the electric drive line-to-line voltage measurements. The combined diagnosis signals make possible to detect and identify the single and multiple open-circuit faults of the inverter switches. Furthermore, only one line-to-line voltage is necessary to diagnose two inverter legs simultaneously. For simplicity and cost-effectiveness, the fault detection is carried out by a simple circuit. To avoid the false diagnosis alarms, the time delays due to turn-on and turn-off process of the power switches are compensated while acting on the switching pattern. Different from the conventional method, the proposed technique was marked by a better time delay between the fault occurrence and its detection. The Simulation results are displayed to confirm the proposal.

Proceedings ArticleDOI
27 Jun 2011
TL;DR: A new approach for improving the estimation of the global position of a vehicle in complex urban environments by means of visual odometry and map fusion to improve dynamic traffic management is described.
Abstract: This paper describes a new approach for improving the estimation of the global position of a vehicle in complex urban environments by means of visual odometry and map fusion. The visual odometry system is based on the compensation of the heterodasticity in the 3D input data using a weighted nonlinear least squares based system. RANdom SAmple Consensus (RANSAC) based on Mahalanobis distance is used for outlier removal. The motion trajectory information is used to keep track of the vehicle position in a digital map during GPS outages. The final goal is the autonomous vehicle outdoor navigation in large-scale environments and the improvement of current vehicle navigation systems based only on standard GPS. This research is oriented to the development of traffic collective systems aiming vehicle-infrastructure cooperation to improve dynamic traffic management. We provide examples of estimated vehicle trajectories and map fusion using the proposed method and discuss the key issues for further improvement.

Proceedings ArticleDOI
27 Jun 2011
TL;DR: A trade-off model for system dynamic performance and system security can be used to adapt security configurations to provide sufficient protection and satisfy real-time dynamic performance requirements of the NCS simultaneously.
Abstract: Networked Control Systems (NCS) is a fast growing technology that integrates distributed sensors, actuators, and computing processors over a communication network for a vast amount of applications. However, the NCS can be vulnerable to various network attacks when the network used is insecure (e.g., Internet). Thus, secure NCS need to have embedded security mechanism to ensure its security operating requirements, which may sacrifice its performance due to limited system resources. This paper addresses the trade-off between NCS security and its real-time performance and use a secured networked DC motor system for illustration. This paper will present a trade-off model for system dynamic performance and system security. This model can be used to adapt security configurations to provide sufficient protection and satisfy real-time dynamic performance requirements of the NCS simultaneously. The construction of this model includes the development of a set of metrics to quantitatively measure the performance and security levels of NCS and the development of a trade-off objective function incorporating performance and security. A Simulink based test-bed implemented to control the speed of the DC motor is used to illustrate the effectiveness of this model.

Proceedings ArticleDOI
27 Jun 2011
TL;DR: In this paper, a single-phase modular multilevel inverter based photovoltaic system for grid connection is proposed, which utilizes two conversion stages; a boost converter for tracking the maximum power point and a modular multi-level inverter used as an interfacing unit.
Abstract: A single-phase modular multilevel inverter based photovoltaic system for grid connection is proposed. This photovoltaic system utilizes two conversion stages; a boost converter for tracking the maximum power point and a modular multilevel inverter used as an interfacing unit. The maximum power point tracking is achieved with a fuzzy logic controller, and the modular multilevel inverter regulates the dc link voltage and synchronizes the grid voltage and current in order to achieve unity power factor operation. The proposed system provides high dynamic performance and power quality injected into the grid. The validity of the proposed system is confirmed by simulations.