To acquire electrical safety
knowledge and, to comprehend the usage of the acquisition tools and interface
of the laboratory equipment components known as Lab-Volt and preforming an
identical test on Simulink.
Equipment and Materials:
Understand the necessary safety knowledge by watching the
Lab-Volt Lab Video. Implement the circuit shown in figure 1 into Simulink; a
MATLAB software that runs virtual scenarios of real-word systems. Simulink is
found on the topmost toolbar section in MATLAB, and we’ll be observing the power,
current, and voltage that is used.
A: DC Setup
on scopes are for easier distinction; Blue is Voltage, Red is Current.
components to build the circuit can be found in the library portion of
Simulink, which is the symbol located on the top toolbar that’s noted as four squares.
All the components can be found either under “Simscape” or the power library (“powerlib”).
For the system to work in Simulink, the “powergui” block needs to be placed on
the main Simulink window. Then place a DC voltage source that’s set to 30 volts.
To set a resistor, an RLC branch is needed, and ground can then be found in the
sources tab. A voltmeter and an ammeter will then be placed at the specified
location in Figure 1; these will be named “voltage measurement” and “current
measurement” in Simulink. Connect scopes to the output of the measurement
blocks to measures those two parameters, and a completed circuit from Simulink
is shown in Figure 2.
B: AC Setup
An AC setup will be used on the same
circuit that was just built. This is done by replacing the DC power source with
an AC source that has a 30-volt amplitude at a frequency of 60 Hz, and Figure 3
is an example of this setup.
A sample size of 10 voltage readings
that vary in increments of 5 volts will be used in measures to compensate for
the varying voltage in an AC power source. An average peak-to-peak value of the
current will be used as a measurement for power.
The scopes must be opened to get measurements of the circuit;
double clicking the scopes on the interface to bring up the scope window will
achieve this. The simulation must be started by pressing the “play” button
before the scope begins to show the data measurements, and this data is shown
in Figures 4 and 5.
The acquired data shows
that the measured voltage is the same as the source voltage. This is due to
voltage staying constant for a DC power source, which assures that the measured
current is correct. The scope has measured the current as being 0.1A or 100mA,
and Ohm’s law will be used to find the power as .
the same method as previously stated in the DC Measurements, will be applied in
the measurement for AC. Below are the scope illustrations acquired from
Simulink. See 6 and 7.
same method used for the DC measurements will also be used for this section.
Figures 6 and 7 shows the data from the scopes that was taken.
Law will be used to compare the theoretical and experimental data using
of the varying power that’s outputted by an AC source, the data comparison for
this section will be more thorough through use of the average peak-to-peak
value. Figure 8 shows an example of how the values were obtained. Further showing
the correlation between voltage and current, since the voltage varies with time,
the current will also vary in time; table 2 then shows a comparison between the
theoretical and experimental data.
theoretical power that’s outputted is slightly higher than the experimental values;
this is due to the chosen time parameters, and because of how many significant
figures are used for the sine function. The absolute error between measured and
predicted values is represented by the function: . Table 3 shows the error with the corresponding voltage.
As shown by the table
above, the error is slight as previously stated. This is most likely caused by
a slight over estimation on the current due to using less significant figures
and the times chosen for sampling. A visual representation of the Theoretical
and Experimental power dissipation vs. Voltage and the Absolute Error Function
vs. Voltage is provided below. See Fig 9 and 10.