Z – SOURCE INVERTER – DESIGN

• POWER =16W
• V_IN=12V
• I_IN=1.33A
• V_OUT=16V ,
• I_OUT =1A
• Gain of converter = T /( T_OFF -T_ON)

ON TIME CYCLE CALCULATION

Gain of converter = V_OUT /V_IN

Gain of converter = 16V /12V

Gain of converter =1.33

V_OUT = V_IN T /( T_OFF -T_ON)

16 = 12 T /( T_OFF -T_ON)

1.33 = T /( T_OFF -T_ON)

T_OFF = T-T_ON

take switching frequency is 60kHz

the time=16µs

1.33 = T /( T-T_ON -T_ON)

1.33 = T /( T -2T_ON)

1.33 = 16µs /( 16µs -2T_ON)

solving above we get

T_ON = 2µs

INDUCTOR VALUE CALCULATION

WHEN THE SHOOT THROUGH STATE , V_IN= V_L =12

FOR AN INDUCTOR VOLTAGE CURRENT BASIC RELATION IS

V_L = L * dI / dt

THEN, L = V_L * dt / dI

L = V_IN * dt / dI

HERE dt =2µs —- DUTY CYCLE / FREQUENCY

Assume that operating frequency of the switch (mosfet here) =60 kHz

AND dI IS THE RIPPLE CURRENT OF INDUCTOR

I_L = I_IN =1.33A

Assume that inductor ripple current = 10% of inductor current

dI =10% * I_L

dI = .133A

L = V_IN * dt / dI

L = 12V * 2µs / .133A

L = 180µH

OUTPUT CAPACITOR C1 AND C2 VALUE

FOR A CAPACITOR VOLTAGE CURRENT BASIC RELATION IS

I = C * dV / dt

C = I * dt / dV

dV is output ripple voltage. Assume that output ripple voltage is about 0.01% of output voltage

dV = 0.01% * 18V

dV = 0.0016 V

C = I * dt / dV

C = 1.33 * 2µs / 0.0016

C = 1662µF

SIMULATION

3-PHASE SIMULATION

3-PHASE GATE SIGNAL TABLE

SINGLE PHASE

HARDWARE – SINGLE PHASE

CIRCUIT – SINGLE PHASE

GATE SIGNALS WITH SHOOT THROUGH – SINGLE PHASE

Program – single phase (compiler – mikro c for dspic)

//crystal of 16 MHz
#define s1   LATE.F0        //S1
#define s2   LATE.F1        //S2
void main()
{
    TRISE.F0=0;TRISE.F1=0;
    s1=0;s2=0;
    while (1)
    {
        s1 =1;   Delay_us(15);   s2 =1;Delay_us(2);s1 =0;
        s2 =1;   Delay_us(15);   s1 =1;Delay_us(2);s2 =0;
    }
}

Program – 3 phase – not tested it with hardware (compiler – mikro c for dspic)

//crystal of 16 MHz
#define s1   LATE.F0        //S1
#define s2   LATE.F1        //S2
#define s3   LATE.F2        //S3
#define s4   LATE.F3        //S4
#define s5   LATE.F4        //S5
#define s6   LATE.F5        //S6
void main()
{
    TRISE.F0=0;TRISE.F1=0;TRISE.F2=0;TRISE.F3=0;
    TRISE.F4=0;TRISE.F5=0;
    s1=0;s2=0;s3=0;s4=0;s5=0;s6=0;
    while (1)
    {
        s1 =1;s3 =1;s5 =1;   Delay_us(16);   s6 =1;Delay_us(1);s3 =0;
        s1 =1;s6 =1;s5 =1;   Delay_us(16);   s2 =1;Delay_us(1);s5 =0;
        s1 =1;s6 =1;s2 =1;   Delay_us(16);   s4 =1;Delay_us(1);s1 =0;
        s4 =1;s6 =1;s2 =1;   Delay_us(16);   s3 =1;Delay_us(1);s6 =0;
        s4 =1;s3 =1;s2 =1;   Delay_us(16);   s5 =1;Delay_us(1);s2 =0;
        s4 =1;s3 =1;s5 =1;   Delay_us(16);    s1 =1;Delay_us(1);s4 =0;
    }
}

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