Analysis and modeling of the steady state behavior of the staticKramer induction generator

A steady state analysis of the static Kramer variable speed double output induction generator is conducted using a hybrid dq model wherein stator variables only are transformed onto a reference frame fixed to the rotor. Rotor variables are retained in their natural abc form, allowing diode bridge overlap together with switching effects in the rectifier and inverter to be catered for. For constant speed operation, the system equations are reduced to a set of linear differential equations with constant coefficients which are solved analytically to predict generator performance. Simulated performance is verified experimentally showing very good agreement with measurement     

Spatial reasoning about multimedia document for a profile based adaptation

The continuous evolution of smart devices has led to serious limitations in multimedia applications. The multimedia graphic design and animation and the increased use of rich and complex multimedia content on the web or other media have all created a need to diversify the accessibility of the content. Therefore several techniques are used today to design a universally accessible content. The main techniques that are still used to maintain accessibility is to create two parallel streams of design and development of the same content. Thus, the continuous evolution will certainly lead to create other streams. For this, the automatic reasoning on multimedia to allow a computer to modify the design according to different variables, devices capabilities, user status and context to provide personalized adapted content. In this paper, we propose an abstract document model called XMS short for XML Multimedia Specification; it describes the composition of an original multimedia document and can be extended to any document type. We present how we may use spatial information present in this document to adapt and modify the original document. We mainly focus on the spatial aspect of a web document, a combination of RCC8, qualitative distances, and directions are used to describe the layout of a set of objects. The level of granularity of the definition of the objects defines the level of details that will be processed by our PROLOG based inference system, simplified versions of algorithms from the inference system and how it works on the spatial dimension of the document are shown. In the end samples of how spatial relations manipulation algorithms work are illustrated.     

A step-down chopper-controlled slip energy recovery induction motordrive

The design of a chopper-controlled slip energy recovery drive, also known as a static Kramer drive, demands an exact knowledge of the steady state and dynamic performance of the system over the complete operating range. To accomplish this, a coupled circuit approach is necessary whereby the self and mutual coupling effects, voltage and current harmonics in the machine and voltage and current ripple at different points in the drive system are duly taken into account. Such a model should enable the accurate prediction of all instantaneous current values which leads to accurate prediction of electric torque and harmonics injected into the supply. This paper presents a model to accomplish the above. Mathematical predictions are verified with experimental results     

A Review of Security in Internet of Things

Wireless Personal Communications - The application of VANET can be divided into two types: security and non-security. Non-secure applications are primarily used to provide entertainment...     

Calculation of slip energy recovery induction motor drive behaviorusing the equivalent circuit

A transformer-type equivalent circuit model for the calculation of the steady state performance of a slip energy recovery induction motor drive with a step down chopper in the DC link is described. Experimental data of RMS currents, power, reactive power and overall efficiency satisfactorily correlate with calculations over most of the operating speed range. Also, detailed calculations of rotor, stator and supply harmonic currents due to the rectifier and inverter actions are performed using the conventional version of the equivalent circuit. The computed and measured instantaneous current waveforms show satisfactory agreement except at a slip of 1/6 where significant deviations appear. This effect is adequately catered for by using a more rigorous model     

Harmonic analysis of slip energy recovery induction motor drives

The impact of electric drives on the power system in terms of harmonic generation is becoming increasingly important. Slip energy recovery induction motor drives (SERIMDs) have the rectifier and inverter connected to the rotor instead of the stator (the case in most conventional drives). The harmonic content of the SERIMD is thus quite different and arguably, less onerous than conventional drives. This paper examines the harmonic content of key waveforms of SERIMDs. Predicted results are supported by extensive experimental results