dSPACE Research Articles

Real-time hybrid substructuring of a base isolated building considering robust stability and performance analysis

This paper demonstrates a real-time hybrid substructuring (RTHS) shake table test to evaluate the seismic performance of a base isolated building. Since RTHS involves a feedback loop in the test implementation, the frequency dependent magnitude and inherent time delay of the actuator dynamics can introduce inaccuracy and instability. The paper presents a robust stability and performance analysis method for the RTHS test. The robust stability method involves casting the actuator dynamics as a multiplicative uncertainty and applying the small gain theorem to derive the sufficient conditions for robust stability and performance. The attractive feature of this robust stability and performance analysis method is that it accommodates linearized modeled or measured frequency response functions for both the physical substructure and actuator dynamics. Significant experimental research has been conducted on base isolators and dampers toward developing high fidelity numerical models. Shake table testing, where the building superstructure is tested while the isolation layer is numerically modeled, can allow for a range of isolation strategies to be examined for a single shake table experiment. Further, recent concerns in base isolation for long period, long duration earthquakes necessitate adding damping at the isolation layer, which can allow higher frequency energy to be transmitted into the superstructure and can result in damage to structural and nonstructural components that can be difficult to numerically model and accurately predict. As such, physical testing of the superstructure while numerically modeling the isolation layer may be desired. The RTHS approach has been previously proposed for base isolated buildings, however, to date it has not been conducted on a base isolated structure isolated at the ground level and where the isolation layer itself is numerically simulated. This configuration provides multiple challenges in the RTHS stability associated with higher physical substructure frequencies and a low numerical to physical mass ratio. This paper demonstrates a base isolated RTHS test and the robust stability and performance analysis necessary to ensure the stability and accuracy. The tests consist of a scaled idealized 4-story superstructure building model placed directly onto a shake table and the isolation layer simulated in MATLAB/Simulink using a dSpace real-time controller.

Bourbaki and Palais Proper Actions on d-Algebra

The main goal of this paper is to create a general two types of proper D-space, namely, Bourbaki proper D-space and Palais proper D-space, to explain the relation between Bourbaki proper and Palais proper D-spaces and to study some of examples and propositions of Bourbaki proper and Palais proper D-spaces.

An improved robust MPPT control for variable speed wind turbine without mechanical sensor: Exprimental evaluation

This paper presents a robust sensorless control scheme of permanent magnet synchronous generators (PMSG) wind turbine with two full-scale controllable three phase converter connected to the grid. The main aim is to drive wind turbine at an optimal rotor speed in order to perform maximum power point tracking (MPPT) control of the wind generation system. The proposed strategy combine a nonlinear backstepping control of the PMSG which is based on both feedback laws and Lyapunov theory, and a non-linear sliding mode observer(SMO) to estimate the PMSG rotor position and to perform a sensorless control. The PMSG wind turbine is integrated to the grid through a three phase inverter which is controlled with classical proportional integral (PI) to control the active and reactive power. The proposed method was successfully tested with both simulation and experimental setup using MATLAB and a dSPACE 1104 platform. The obtained simulation and experimental results show clearly the accuracy and the effectiveness of the proposed method.

Numerical and Experimental Comparison of the Control Techniques Quasi-Sliding, Sliding and PID, in a DC-DC Buck Converter

In this paper the Sliding Mode Control (SMC), PID and ZAD (Zero Average Dynamic) strategies are applied to an electronic DC-DC power converter. Time behavior for each controller is shown for numerical solution and experimental realization. The results in SMC and PID are contrasted with a ZAD-FPIC controller combined with a recently developed strategy named FPIC (Fixed Point Induction Control). Stability in SMC is guaranteed by the Lyapunov theorem. The PID controller is designed in an analytical way using pole placement. The main problem with the physical realization was the sample and hold in the variable acquisition system, in addition to time delay introduced by the computing process. From a practical point of view, the ZAD-FPIC technique has advantages no shown by PID and SMC working with sample and hold, these advantages have been corroborated experimentally. The designs have been tested in an RCP (Rapid Control Prototyping) system based on DSP from the dSPACE platform. Both numerical performance and experimental performance agree.

Type-2 Fuzzy Logic Predictive Control of a Grid Connected Wind Power Systems with Integrated Active Power Filter Capabilities

This paper proposes a real-time implementation of an optimal operation of a double stage grid connected wind power system incorporating an active power filter (APF). The system is used to supply the nonlinear loads with harmonics and reactive power compensation. On the generator side, a new adaptive neuro fuzzy inference system (ANFIS) based maximum power point tracking (MPPT) control is proposed to track the maximum wind power point regardless of wind speed fluctuations. Whereas on the grid side, a modified predictive current control (PCC) algorithm is used to control the APF, and allow to ensure both compensating harmonic currents and injecting the generated power into the grid. Also a type 2 fuzzy logic controller is used to control the DC-link capacitor in order to improve the dynamic response of the APF, and to ensure a well-smoothed DC-Link capacitor voltage. The gained benefits from these proposed control algorithms are the main contribution in this work. The proposed control scheme is implemented on a small-scale wind energy conversion system (WECS) controlled by a dSPACE 1104 card. Experimental results show that the proposed T2FLC maintains the DC-Link capacitor voltage within the limit for injecting the power into the grid. In addition, the PCC of the APF guarantees a flexible settlement of real power exchanges from the WECS to the grid with a high power factor operation.

Robust SVM-direct torque control of induction motor based on sliding mode controller and sliding mode observer

This paper proposes a design of control and estimation strategy for induction motor based on the variable structure approach. It describes a coupling of sliding mode direct torque control (DTC) with sliding mode flux and speed observer. This algorithm uses direct torque control basics and the sliding mode approach. A robust electromagnetic torque and flux controllers are designed to overcome the conventional SVM-DTC drawbacks and to ensure fast response and full reference tracking with desired dynamic behavior and low ripple level. The sliding mode controller is used to generate reference voltages in stationary frame and give them to the controlled motor after modulation by a space vector modulation (SVM) inverter. The second aim of this paper is to design a sliding mode speed/flux observer which can improve the control performances by using a sensorless algorithm to get an accurate estimation, and consequently, increase the reliability of the system and decrease the cost of using sensors. The effectiveness of the whole composed control algorithm is investigated in different robustness tests with simulation using Matlab/Simulink and verified by real time experimental implementation based on dS pace 1104 board.

Design of hydraulic active stabilizer bar test platform based on dSPACE

Design of hydraulic active stabilizer bar test platform based on dSPACE

Not every transitively D-space is D

In 2008, Liang-Xue Peng defined a weakening of the D-space property known as the transitively D property. He asked whether or not every transitively D-space is D. We show that three different examples of linearly Lindelöf, non-Lindelöf spaces are transitively D but not D, answering Peng's question in the negative.

Performance of synchronous reluctance generator for DG set based standalone supply system

This paper presents the performance of a SyRG (Synchronous Reluctance Generator) for DG (Diesel Engine Driven Generator) set based standalone generating system. A STATCOM (Static Compensator) is used for its voltage control, harmonics reduction and load balancing on a SyRG based DG set. The proposed system consists of a diesel engine driven specially designed SyRG with a rating of 3-phase, 3.7kW, 50Hz, 4-pole, 230V line voltage SyRG, an excitation capacitor bank of 6.25kVAr and a STATCOM of 5kVA. The modified PBT (Power Balance Theory) based control algorithm is used to estimate the reference source currents for control of STATCOM. A DSP (dSPACE) is used to implement this control algorithm of STATCOM. The performance of the proposed system is studied using STATCOM which improves the performance by exchanging the reactive power with the system. The source of reactive power is a capacitor bank and VSC (Voltage Source Converter) with a DC link capacitor used as STATCOM. The gating signals of VSC of the STATCOM are generated using PBT based control algorithm. The energy stored in the DC link is exchanged with the system to eliminate harmonics, voltage regulation and load balancing. The performance of the SyRG based standalone DG system is observed under a linear load of 3.19kW with power factor of 0.8 and a nonlinear load of 2.99kW under both balanced and unbalanced conditions. The proposed system has maintained fixed terminal voltage at 220V, voltage and current harmonics within 5% under highly nonlinear load and balanced source currents under highly unbalanced load currents.

Using Logstash and ElasticSearch to Achieve Real-time Statistical Analysis of DSpace Logs

Using Logstash and ElasticSearch to Achieve Real-time Statistical Analysis of DSpace Logs

Real Time Implementation of A Fuzzy Logic Based Mppt Controller for Grid Connected Photovoltaic System

The present work investigates a real time implementation of a photovoltaic grid connected chain, based on fuzzy logic MPPT controller (FLC). The implementation is realized on a dSPACE 1104 single board, controlling a boost chopper in the PV array side and a VSI inverter in the grid side. The FLC tracks permanently the maximum power point of the PV array without any prior information on the system model. The DC-link voltage controller is based on Lyapounov stability theory ensuring best performance for both transient and steady state, whereas, the hysteresis current controllers of the inverter allow a quasi-total transit of the maximum extracted PV power to the grid under unity power factor operation. The obtained results via Matlab-Simulink simulation are confirmed through experiment proving the effectiveness of the used control method.

MPC for Reduced Voltage Source Multicell Converter

Multicell converters are having advantages like sharing the voltage stress between the switches, but the disadvantage with their configuration is that it requires two voltage sources and many number of switching cells with flying capacitors, this disadvantage is overcome with a configuration named reduced voltage source multicell converter. This converter is analyzed in brief for different number of levels and validated for its working using dSPACE. A Model Predictive Control (MPC) is designed for this configuration, the designed model predictive controller is verified with MATLAB Simulation. The MPC controller is verified with change in reference voltage and it has been found that the output controlled voltage almost follows the reference voltage with less peak overshoot. The results presented in this article confirms that the MPC acts as a suitable controller for a multicell converters where large number of switches are involved along with capacitors.

Fuzzy Sliding Mode Control for Parallel DC-DC Boost Converter

Nowadays, parallel DC-DC switched converters are commonly used in many applications such as distributed power supply systems and embedded systems to extend battery life. As a single switched mode DC-DC converter topology, a parallel converter must provide a regulated output voltage. For such case the regulation of the voltage must be performed in a closed loop control mode. In this paper, a Fuzzy Sliding Mode Control (FSMC) is developed and applied to a two parallel DC-DC converter. Fuzzy Sliding Mode Control is a robust control which combines the benefits of fuzzy logic control and sliding mode control. The proposed FSMC is implemented in real time using a dSPACE control board. The efficiency and the robustness of the proposed controller are tested by simulation and experimentally, with success, for different operating conditions

Performance Investigation of Active Power Filter Under Non-Linear Loads Variation

This paper aims on details performance of three-phase shunt active power filter (APF) having variation of DC non-linear loads implemented in real-time control using dSPACE DS 1104 is presented. The APF was implemented by using stationary reference frame (d-q algorithm) and the purpose is to extract the harmonics content in the system. In addition, 9 kHz carrier signal are used to generated the switching signal which are used to correct the harmonics in the system. The non-linear loads were constructed with three-phase rectifier which connected in series with inductor and parallel with resistor and capacitor. In this experiment, three cases have been investigated to analyze the performance of the APF. The results shows the improvement of the THDi are ranging from 92% to 94%. The best reduction of the THDi are founded with both load at maximum values

A New Alternate Fixed-Bias Inverter SVPWM Scheme for Open-end Winding Induction Motor Drive

This paper proposes a new space-vector based Pulse Width Modulation (PWM) scheme for an open-end winding induction motor drive. This PWM scheme requires two isolated power supplies and uses instantaneous phase reference voltages. The circuit configuration requires two isolated power supplies for the dual inverter fed open end winding induction motor drive. By exploiting the rich switching redundancy that is offered by the circuit configuration, all the active states are used in clamping the inverters. The proposed scheme is simulated using MATLAB/Simulink platform and the simulated results are validated using dSPACE experimentation

English

The main purpose of this paper is to provide practical guidelines of setting up an institutional repository through ds pace open source software. In the electronic publishing age, the demand for information has been growing steadily in all spheres of work. At the same time the concept of access to information at the free of cost in electronic format is gaining momentum. In this direction present paper discussed step by step procedures in building an institutional repository using ds pace including collections. This paper helps in planning to build an IR. It also helps the beginners in understanding the steps to be followed for uploading different file formats to build digital repository to maintain collection with uniformity. DESIDOC Journal of Library & Information Technology , 2014, 33(6), pp. 474-479. http://dx.doi.org/10.14429/djlit.33.5478

DRDO Knowledge Repository

This paper deals with knowledge management and its need and benefit to R&D organisation. It describe the importance of standard format or guidelines for writing and assigning uniform numbers to technical reports in DRDO. It Ddiscusses in detail the establishment of DRDO Knowledge Repository (KR). Main emphasis has been given on how to use DSpace as open source software, scope of work in DRDO KR, installation and customisation of input data field, metadata creation, and uploading. http://dx.doi.org/10.14429/djlit.33.4890

Real Time Implementation of Multi Carrier Based PWM Techniques for Single Phase Nine Level Trinary Source CMLI Using dSPACE

Multi carrier based Pulse Width Modulation techniques have been implemented for switching of prototype of single phase trinary source cascaded multilevel inverter in which 9- level output voltage can be achieved with fewest components. Different species of Carrier Overlapping Pulse Width Modulation (COPWM-A, COPWM-B and COPWM –C) strategies along with trapezoidal reference are used. The gating pulses are generated using dSPACE dS1103 Real Time Interface (RTI) hardware and control desk with MATLAB- SIMULINK environment. It is observed that COPWM-A provides relatively lower THD. Relatively higher RMS output voltage for modulation index ma=0.8 to 1 is obtained with COPWM – B. The performance indices used are Total Harmonic Distortion (THD), Root Mean Square (RMS) output voltage, Crest Factor (CF),Form Factor (FF) and Distortion Factor (DF).

Performance Evaluation of Real Time Implementation of New Hybrid PWM Strategies for Single Phase Seven Level Asymmetrical Inverter

Carrier Based Pulse Width Modulation (CBPWM) techniques have been used widely for switching of multilevel inverters due to simplicity and reduced computational requirements than the Space Vector Modulation (SVM). New hybrid carrier based PWM strategies have been implemented for a prototype of single phase seven level asymmetrical inverter in this work. Two inverter bridge circuits are used to achieve seven level output voltage. Phase Disposition (PD), Phase Opposition Disposition (POD), Alternate Phase Opposition Disposition (APOD) and Carrier Overlapping (CO) PWM strategies are used with triangular carriers above zero axis and rectified sine carriers below zero axis along with stepped reference. The triggering pulses are generated using the dSPACE dS1103/Real Time Interface (RTI) hardware and front end tool control desk with MATLAB-SIMULINK environment. The performance indices used are Total Harmonic Distortion (THD), Form factor (FF), Distortion Factor (DF), Root Mean Square (RMS) output voltage. It is observed that COPWM provides relatively better DC bus utilization and relatively lesser harmonic distortion for modulation index ma=0.7-1

Anwesan: A Search Engine for Bengali Literary Works

Most of India's literature was written in Bengali since the beginning of the 19th century. Hundreds of authors have contributed to the enrichment of Bengali literature for years. Besides that, nearly 300 million people around the world speak in Bengali. The language, having a rich traditional background and popularity throughout the world, must be taken care for the web users in the present era of World Wide Web (WWW). The digitization of Bengali literary works and the development of the search engine is very important for the benefit of the Bengali language users all over the world. The paper describes Anwesan, a search engine for Bengali literature. Currently the entire work of Rabindranath Tagore and a part of Bankim Chandra Chattopadhyay's work is searchable through Anwesan. Several advanced search features necessary for simple and expert users are supported. It also serves as a digital library with various metadata information. The engine is implemented by customizing DSpace in Bengali language and is perhaps the most exhaustive exercise in this direction. This search system was primarily open for the public in Kolkata Book Fair 2010 only with Rabindra Rachanabali collection. Since then,its been in high use.