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National University
of Computer and Emerging Sciences
Chiniot-Faisalabad Campus
EE324 – Power Electronics
Assignment Number 1
“Power Electronic Devices and Circuits”
Spring 2020
Maximum Marks: 40 Due Date: 10th^ February 2020
Submitted By
Name: Muhammad Haseeb Ahsan__
Student ID: 16F-8351__ ___________
Section: _EE16(A)__________________
Submitted To
Engr. Arslan Ahmed Amin
Lecturer – EE Department
Submission Date
10 th^ February 2020
Details of Obtained Marks
Question Number 1 2
Total
CLO Number 1 1
Total Marks 20 20 40
Obtained Marks
Contents
- AC – AC CYCLOCONVERTER:..................................................................................................................
- DESCRIPTION:....................................................................................................................................
- CIRCUIT DIAGRAM:............................................................................................................................
- WAVEFORMS:....................................................................................................................................
- MATHEMATICAL EXPLANATION:........................................................................................................
- AC – DC RECTIFIER:................................................................................................................................
- CIRCUIT DIAGRAM:............................................................................................................................
- WAVEFORMS:....................................................................................................................................
- MATHEMATICAL EXPLANATION:........................................................................................................
- DC-DC CHOPPER:...................................................................................................................................
- CIRCUIT DIAGRAM:............................................................................................................................
- WAVEFORMS:....................................................................................................................................
- MATHEMATICAL EXPLANATION:........................................................................................................
- DC – AC INVERTER:................................................................................................................................
- CIRCUIT DIAGRAM:............................................................................................................................
- WAVEFORMS:....................................................................................................................................
- MATHEMATICAL EXPLANATION:........................................................................................................
- QUESTION # 02:.....................................................................................................................................
- EXAMPLE # 57:...................................................................................................................................
- CIRCUIT DIAGRAM:............................................................................................................................
- WAVEFORMS:....................................................................................................................................
- MEASUREMENTS:............................................................................................................................
- EXAMPLE # 58:.................................................................................................................................
- CIRCUIT DIAGRAM:..........................................................................................................................
- WAVEFORMS:..................................................................................................................................
- MEASUREMENTS:............................................................................................................................
- Reference:...........................................................................................................................................
- Plagiarism Report:...............................................................................................................................
MATHEMATICAL EXPLANATION: AC – DC RECTIFIER:
A rectifier[2] is an electrical device that converts an Alternating Current (AC) into a Direct
Current (DC) by using one or more P-N junction diodes.
Figure 3 AC - DC Rectification [2]
The rectifiers are mainly classified into two types:
Half-wave rectifier
Full-wave rectifier
CIRCUIT DIAGRAM: Figure 4 AC - DC Full Wave Rectification [2] WAVEFORMS: Figure 5 AC - DC Full Wave Rectification MATHEMATICAL EXPLANATION:
The no-load output DC voltage of an ideal half-wave rectifier for a sinusoidal input voltage
is:
WAVEFORMS: Figure 8 Waveforms [3] MATHEMATICAL EXPLANATION:
Let us now take a look at the output current and voltage waveforms of a chopper. During the
time period Ton, the chopper is turned on and the load voltage is equal to source voltage Vs.
During the interval Toff, the chopper is off, and the load current will be flowing through the
freewheeling diode FD. The load terminals are short-circuited by FD and the load voltage is,
therefore, zero during Toff. Thus, a chopped dc voltage is produced at the load terminals. We
can see from the graph that the load current is continuous. During the time period Ton, load
current rises but during Toff load current decays.
Average load Voltage is given by
V 0 = Ton /( Ton + Toff )∗ Vs =( Ton / T ) V = A Vs
Ton: on -time
Toff: off- time
T = Ton +Toff= chopping period
A = Ton /T = duty cycle
So, we know that the load voltage can be controlled by varying the duty cycle A. Above
equation shows that the load voltage is independent of load current it can be also written as
V0 = f* Ton* Vs
f= 1/T = chopping frequency
DC – AC INVERTER:
An Inverter[4] is an electronic device capable of transforming a DC (DC) current into an
alternating current (AC) at a given voltage and frequency. It is therefore indispensable to use
it to power by DC, electrical devices that work in AC. The Simple example of DC – AC
Inverters is IGBTs based inverters.The input voltage, output voltage and frequency, and
overall power handling depend on the design of the specific device or circuitry. The inverter
does not produce any power; the power is provided by the DC source. A power inverter can
be entirely electronic or may be a combination of mechanical effects (such as a rotary
apparatus) and electronic circuitry.
CIRCUIT DIAGRAM: Figure 9 DC - AC Single Phase Half Bridge IGBT Inverter [5] WAVEFORMS: Figure 10 Single Phase Half Bridge IGBT Inverter Wavedorms [6] MATHEMATICAL EXPLANATION:
The inverter circuit[7] consists of two choppers. whenonly transistor Q1 is turned ON for a
time T0/2 then instantaneous voltage across the load is (V0=Vs/2). If the transistor Q2 only is
turned ON for a time T0/2,-VS/2 appears across the load. This type of inverter is called Half
bridge inverter.
Instantaneous output voltage in the form of Fourier series is-
Output voltage- Where v0 = 0 for n=2,4…..
MEASUREMENTS: Figure 13 MATLAB Measurements EXAMPLE # 58: CIRCUIT DIAGRAM: Figure 14 MATLAB Simulink Circuit
WAVEFORMS: Figure 15 MATLAB Scope View MEASUREMENTS: Figure 16 MATLAB Measurements
