Boost Converter

BOOST converter

• Widely Used in regulated Switch mode DC power supply

• Variable DC input Voltage is obtained by PV array cells• Four Basic components –Electronic Switch, Inductor,

Diode and output Capacitor• Works on two modes-Continuous mode and

Discontinuous mode which depends upon Energy injection and absorption of the circuit

Circuit Model of Boost converter

Continuous Mode

• Mode 1(0<t ≤ ton)

• Mode 2 (ton<t<t)

cycledutyisDvoltageinputisV

VoltageoutputisVwhereD11

VV

i

o

i

o

currentinputisIcurrentoutputisIwhere

D11

II

i

o

i

o

Discontinuous Mode

• Mode 1 and Mode 2 is same as Continuous Modes

• Mode 3(toff <t<T)

DDD

II

directionnegetiveintimeonturnisDDDD

VV

11

i

o

1

1i

o

Simulation of DC-DC Boost COnverter

• Selection of Semiconductor Device

currentloadtocurrentrippleofpercentis*

pvinpoweroutputimummaxisP

VP*

VP

I

cellPVofvoltageMaximumisV

deviceswitchingonsstressvoltageMaximumisVwhere

VV

max,in

pv

max,in

pv

max,inpeak

max,pv

stressmax,

max,pvstressmax,

• Selection of Inductor

resistanceloadequvalentisRcycledutyisD

frequencyswitchingisFF*2

)D1(D*RL

s

s

2c

• Selection of Capacitance Required

resistanceequivalentisRvoltagerippleisΔV

cycledutyisDfrequencyswitchingtheisF

voltageoutputtheisVR*V*F

D*VC

o

s

o

os

ob

• Selection Of Diode1. Ability to block required off state voltage stress

2.Sufficient peak and average handling capability

3. Fast Switching Characteristics 4.Low reverse recovery current 5.Low Forward Voltage Drop