02-01-2013, 01:20 PM
SIMULINK/MATLAB AS A TOOL FOR SIMULATION
SIMULINKMATLAB AS A TOOL FOR SIMULATION.doc (Size: 56 KB / Downloads: 32)
Introduction
Simulation is a tool for the understanding of many complex problems. Several digital simulation packages are commercially available. This chapter presents a comparison of the salient features of various simulation tools available to model the electrical drive systems in a digital computer such as PSIM, CASPOC, PSPICE, SABER, SIMPLORER and SIMULINK/MATLAB.
PSPICE is mainly meant for the simulation of electronic circuits. Modeling of machines especially with a feedback control loop becomes very difficult in this package. PSIM and CASPOC take very little time to learn but the micro-modeling of devices is not possible in this package due to which the accuracy of results is quite limited. SABER and SIMPLORER are exclusively meant for power electronic and drive system simulations and they are user-friendly as well. But both these packages are extremely expensive. SIMULINK/MATLAB is a general-purpose simulation tool with several tool-boxes embedded in it to enable modeling of complicated control schemes as well. The power system block set has specifically a large number of components conforming to the needs of an electrical power engineer.
MATLAB
The name MATLAB stands for matrix laboratory. Originally it was meant for providing easy access to the matrix manipulations. Over the years, it has developed into a tool for high productivity analysis, research and development. MATLAB allows the user to focus on his technical work and applications rather than on programming details.
SIMULINK
SIMULINK is a tool-box in MATLAB software that can be used for modeling, simulating and analyzing dynamical systems. It supports linear and nonlinear systems, modeled in Continuous time, sampled time or a hybrid of the two. Systems can also bemultirate, i.e., have different parts that are sampled or updated at differentiates. For modeling SIMULINK provides a graphical user interface (GUI) for building models as block diagrams, using click-and-drag mouse operations. With this interface, we can draw the models just as we would on paper. This is accomplished through the SIMULINK block library of sinks, sources, linear and nonlinear components and connectors.
MATLAB ODE solver functions implement numerical integration. In this package, the ode45 solvers used for a non stiff problem and the ode15s solvers for a stiff problem. In a “stiff” problem, solutions can change on a time scale that is very short compared to the interval of integration.
AC Voltage Source
The AC Voltage Source block implements an ideal AC voltage source. Negative values are allowed for amplitude and phase. A zero frequency specifies a DC voltage source. Negative frequency is not allowed; otherwise Simulink signals an error and the block displays a question mark in the block icon.
Parameters
Peak amplitude: The peak amplitude of the generated voltage, in volts (V).
Phase: The phase in degrees (deg).
Frequency: The source frequency in hertz (Hz).
Sample time: The sample period in seconds (s). The default is 0, corresponding to a continuous source.
Measurements: Select voltage to measure the voltage across the terminals of the AC voltage source block.
Ground
The Ground block implements a connection to the ground.