Precision Control of Single-Phase PWM Inverter Using M68HC11E Microcontroller
Induction motors are being used in greater numbers
throughout a wide variety of industrial and commercial applications
because it provides many benefits and reliable device to convert the
electrical energy into mechanical motion. In some application it-s
desired to control the speed of the induction motor. Because of the
physics of the induction motor the preferred method of controlling its
speed is to vary the frequency of the AC voltage driving the motor. In
recent years, with the microcontroller incorporated into an appliance
it becomes possible to use it to generate the variable frequency AC
voltage to control the speed of the induction motor.
This study investigates the microcontroller based variable
frequency power inverter. the microcontroller is provide the variable
frequency pulse width modulation (PWM) signal that control the
applied voltage on the gate drive, which is provides the required
PWM frequency with less harmonics at the output of the power
The fully controlled bridge voltage source inverter has been
implemented with semiconductors power devices isolated gate
bipolar transistor (IGBT), and the PWM technique has been
employed in this inverter to supply the motor with AC voltage.
The proposed drive system for three & single phase power inverter
is simulated using Matlab/Simulink. The Matlab Simulation Results
for the proposed system were achieved with different SPWM. From
the result a stable variable frequency inverter over wide range has
been obtained and a good agreement has been found between the
simulation and hardware of a microcontroller based single phase
Power, inverter, PWM, microcontroller.
Sensitivity Analysis for Direction of Arrival Estimation Using Capon and Music Algorithms in Mobile Radio Environment
An array antenna system with innovative signal
processing can improve the resolution of a source direction of arrival
(DoA) estimation. High resolution techniques take the advantage of
array antenna structures to better process the incoming waves. They
also have the capability to identify the direction of multiple targets.
This paper investigates performance of the DOA estimation
algorithm namely; Capon and MUSIC on the uniform linear array
(ULA). The simulation results show that in Capon and MUSIC
algorithm the resolution of the DOA techniques improves as number
of snapshots, number of array elements, signal-to-noise ratio and
separation angle between the two sources θ increases.
Antenna array, Capon, MUSIC, Direction-of-arrival estimation, signal processing, uniform linear arrays.