fuzzy based bidirectional buck-boost cascade inverter
Department of electrical and electronics engineering
Gandhiji institute of science and technology Approved by AICTE,NEW DELHI,
Affiliated to JNTU KAKINADA , Gattu Bhimavaram ( p. o)-
JAGGAYYAPET , Krishna District www.gistech.co.in
UNDER GUIDE BY:-
U. NARESH M.Tech
HEAD OF THE DEPARTMENT:-
M.SUNDAR RAO M.Tech
Different Types Of converters
Buck- Boost Converter
Different Types Of Controller( p, pi , pid And Fuzzy)
Advantages, Disadvantages And Application Of Our
This paper proposes a bidirectional buck boost cascade inverter
and presents its modelling and control methods
Here the inverter can be seen as the cascade of a buck converter
and boost converter main inductor current is maintained by
buck stage and out voltage controlled by boost stage
It provides bidirectional operational with bipolar outputs.
It reduces the dead time effect and reduced output distortion
OPERATION OF BUCK STAGE
Buck converter is a dc- dc power converter
it is a class of switched mode power supply(SMPS)
It containing two semiconductors (Diode & IGBT)
To reduce voltage ripple , filters made of capacitor & inductor
Buck converter provide much greater power efficiency
It is used in many industrial application such as cars trolley buses
battery operated vehicles and battery charging etc....
To provide smooth control on output high efficiency , fast response and
To provide long and less maintenance due to absence of moving parts.
Operation of boost stage:-
Output voltage always higher than input voltage
Boost converter is dc-dc power converter
It is a class of switch mode power supply (SMPS)
When switch is “on” : diode is reverse biased output circuit is thus isolated
inductor is charged.
When switch is “off “: output stage received energy from the inductor as
well as input.
Filter capacitor is very large to ensure constant output voltage .
In this diode and transistor is used as switching device .
It is voltage control device and it required small amount of current
Switching speed is very high.
It operates in nano second.
What is a fuzzy controller
Fuzzy logic controller developed by Zadesh in 1965.
Fuzzy logic control is rule based technique.
The rules are “IF THEN” rules
Fuzzy logic control can be well suited to control a system
with uncertain, complex , inaccurate or non linear
In fuzzy logic controller we used membership functions
Why should we use fuzzy controller
It can be easily modified.
Can used multiple inputs and outputs sources.
Very quick and cheaper to implement.
Much similar than its predecessors.
11 A controller in which the output are control signal
is a sum of three signals one being proportional to
error signal one being proportional to integral of
the error signal and third being proportional to
derivative of error signal is known as PID
o It improves the system performance in all aspects
due to combined operation of three.
o “P” of PID controller increase the gain of system.
o “I” of PID controllers decreases the steady state
o “D” of PID controller decreases the rate of change
Compare PID and fuzzy logic controllers
Reduced output distortions.
High performance achieved
Which can be utilized to eliminate the systems non
GREATER POWER EFFICIENCY
HEAT DISSIPATION IS LESS
LESS SEMI CONDUCTOR DIVICES ARE REQUIRED
IT DOES NOT STEP - UP THE OUTPUT CURRENT
IT IS COSTLY AVAILABLE IN THE MARKET
Which can be utilized to eliminate the system nonlinearity , and thus high
Consequently , a decoupled control strategy with feed forward compensation
technique is proposed .