Modelling and Simulation of engineering systems Essay

Modelling and Simulation of engineering systems - Essay Example The main advantage of SIMULINK over other programming softwares is that, instead of compilation of program code, the simulation model is built up systematically by means of basic function blocks. Through a convenient graphical user interface (GUI), the function blocks can be created, linked and edited easily using menu commands, the keyboard and an appropriate pointing device (such as the mouse). A set of machine differential equations can thus be modelled by interconnection of appropriate function blocks, each of which performing a specific mathematical operation. Programming efforts are drastically reduced and the debugging of errors is easy. Since SIMULINK is a model operation programmer, the simulation model can be easily developed by addition of new sub-models to cater for various control functions. As a sub-model the induction motor could be incorporated in a complete electric motor drive system (Wade 495-505; Shi 231-235). A generalized dynamic model of the induction motor consists of an electrical sub-model to implement the three-phase to two-axis transformation of stator voltage and current calculation, a torque sub-model to calculate the developed electromagnetic torque, and a mechanical sub-model to yield the rotor speed. In addition, a stator current output sub-model is needed for calculating the voltage drop across the supply cables. Multiple line equation(s) cannot be represented in ASCII text... ASCII text where Vas, Vbs, and Vcs are the three-phase stator voltages, while Vds and Vqs are the two-axis components of the stator voltage vector Vs. Torque sub-model of induction motor In the two-axis stator reference frame, the electromagnetic T is given by:T = PLm/3(idriqs - iqrids) Mechanical sub-model of induction motor From the torque balance equations and neglecting viscous friction, the rotor speed omega0 may be obtained as follows: Multiple line equation(s) cannot be represented in ASCII text where J is the moment of inertia of the rotor and load and TL is the load torque. Stator current output sub-model The stator current output sub-model is used to calculate the stator current amplitude according to the following equation:|is| = 2/3 square root of (ie, sub ds)2 + (ie, sub qs)2 A SIMULINK Fcn' block is used to implement the above equation. Simulation System Of Induction Motor The complete simulation system of the induction motor includes the induction motor model in a power supply sub-model. Power supply sub-model The voltage supply block consists of a three-phase sinusoidal voltage generator and a terminal-voltage calculation block which accounts for the voltage drop in the supply cable. Simulation Results The induction motor chosen for the simulation studies has the following parameters: Type: three-phase, 7.5 kW, 6-pole, wye-connected, squirrel-cage induction motorRs = 0.288 OMEGA/ph Rr = 0.158 OMEGA/ph Ls = 0.0425 OMEGA/ph Lm = 0.0412 OMEGA/ph Lr = 0.0418 OMEGA/ph J = 0.4 kg m2 JL = 0.4 kg m2 To illustrate the transient operation of the induction motor, a simulation study of direct-on-line starting is demonstrated. At t = 0, the motor, previously

Poverty and Pollution Essay Example | Topics and Well Written Essays - 1750 words - 1

Poverty and Pollution - Essay Example This paper outlines that Cubatao in Brazil, which may be the most polluted area in the whole world, has about 100,000 people living in the valley. Inhabitants have refused to sell their land and resettle elsewhere because of the readily available jobs from the industries and the cheap life around. This paper will examine the ethical implications of pollution in the third world, pollution as the price for progress, moral right to human beings of a livable environment, and global pollution standards. Additionally, the paper will examine whether the wealthy nations have an obligation to provide poorer nations with resources to develop greener industries. Ethical implications of businesses polluting in a third world country are common. First, every animal, plant, and other living things have a right to a better environment. It is unfortunate that pollution destroys their habitat shortens their lives. Additionally, pollution causes the extinction of some animals resulting in an incomplete life cycle of such animals. Living things depends on one another for survival and human beings depend on them. It is unethical that a human decision can result in death and loss of livelihood. Although human beings are superior to other beings, they have an obligation to other human beings and nonhuman beings. Secondly, right to bodily security supersedes all another human right including the right to property. The health of the environment is more important than all other rights because they protect human life. Therefore, pollution is unethical as it undermines a basic human right. Some businesses may conduct operations in a third world country and disregard any standards of pollution control. To reap the benefit of cheap labor and circumvent the strict conditions of working, many companies have moved their factories to third world countries.