it describes: 1- What is AC/AC Converter and its applilcation?
2- AC Converter in resistive and inductive load with equations
3- using phase control and Time Proportional Control
Introduction to Microprocesso programming and interfacing.pptx
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Ac/AC conveter
1. 1
Menoufia University
Faculty of Electronic Engineering
Department of Biomedical Engineering
Supervisor: DR/Essam Nabil
Made by: Nourhan Selem Salm
AC/AC
Converters
11/2019
2. 2
What is AC/AC Converter ?01
content
Resistive load02
Inductive load03
Time Proportional Control04
References05
14. 14
An AC/AC voltage converter made of two thyristors in anti-parallel
connection and driven by a harmonic 220 V, 50 Hz voltage is loaded by a resistor
RL = 2.2 ฮฉ. The holding voltage of the thyristors is VH = 1 V and the resistance
while conducting rd = 5 mฮฉ. If firing angle of the thyristors =
๐
๐
, determine:
(a) the required power of the load (heater),
(b) load power factor,
(c) the rms and average currents of the thyristor current,
(d) power of dissipation in one of the thyristors.
Ans.
(a)
๐ฝ ๐,๐๐๐ =
๐ฝ ๐
๐
๐ โ
๐ถ
๐
+
๐๐๐ ๐๐ถ
๐๐
=
๐๐๐ ๐
๐
๐ โ
๐
๐๐
+
๐๐๐(๐
๐
๐
)
๐๐
= ๐๐๐. ๐๐ ๐ฝ =
๐๐๐
๐
๐ฝ
๐ท ๐ณ =
๐ฝ ๐ถ,๐๐๐
๐
๐น ๐ณ
=
๐๐๐
๐
๐
๐. ๐
= ๐๐ ๐ฒ๐พ
23. 23
For the single-phase voltage controller , the source is
120 V rms at 60 Hz, and the load is a series RL combination with R = 20 ,
L = 50 mH ,and ๐ฐ ๐,๐๐๐ = ๐. ๐๐ ๐จ. The firing angle is 90 and ๐ท = ๐๐๐ยฐ .
Determine :
(a) Critical angle ,
(b) an expression for load current for the first half-period,
(c)the rms SCR current
(d) the power delivered to the load, and
(e) the power factor.
26. 2626
Time Proportional Control
๐ท ๐ณ,๐๐ =
๐ป ๐๐
๐ป ๐๐ + ๐ป ๐๐๐
๐ท ๐ณ๐ด
๐ท ๐ณ๐ด =
๐ฝ ๐,๐๐๐
๐
๐น ๐ณ
๐ท ๐ณ,๐๐ : is the maximum load power without
applied control (Toff = 0)
๐ท ๐ณ,๐๐ =
๐ป ๐๐
๐ป ๐๐ + ๐ป ๐๐๐
ร
๐ฝ ๐,๐๐๐
๐
๐น ๐ณ
27. 27
To the control thyristors in the circuit AC/AC voltage
converter which driven by a harmonic 220 V, 50 Hz voltage is loaded
by a resistor ๐น ๐ณ = 10 ฮฉ. If The TPC technique is applied thyristors
are turned on for m = 25 periods of input voltage and turned off
for n = 75 period ,determine:
(a) the rms value of the output voltage,
(b) the power factor,
(c) the rms and average currents of the thyristor current,
29. 29
References
[1] Daniel Hart, โAC Voltage Controllers,โ in Power Electronics,
McGraw-Hill, 2011.
[2] B. L. Dokiฤ and B. Blanuลกa, Power Electronics Converters and Regulators, 3rd ed.
Springer US, 2015.
[3] V.k.mehta and Rohit-mehta, โSilicon Controlled Rectifiers,โ in principles of electronics,
1st ed., s.chand, 1980.
[4] M. H. Rahid, โAC-AC Converters,โ in Power Electronics Handbook, Academic Press,
2001.