One leg of a diode clamped five level inverter is shown in F

One leg of a diode clamped five level inverter is shown in Figure Q1(a). What are the minimum voltage ratings of the clamping diodes D_1, D_2, D_3, D_4, D_5 and D_6? A single phase 3-level capacitor clamped inverter is shown in Figure Q1 (b). The inner capacitors are pre-charged to the nominal voltage of V_d in the direction shown by the arrows. For a certain switching combination, both the inner capacitors are charged above the nominal voltage. Assuming the direction of the load current as shown in the figure and i_L > 0, determine the switching combination. Use binary notation to indicate the state, S_1S_2S_3S_4 where S_n = 1 if S_n is ON and S_n = 0 if S_n is OFF. What is the voltage across the load during this switching state?

Solution

clamping diode we are using here for the surge protection and so that if the voltage exceeds the rated voltage then it blocks any further current in the circuit

so its voltage is 2 V

Vam = Vdc/2=2/2=1

switch states
output voltage S1 S2 S3 S4 S1\' S2\' S3\' S4\'

V3= Vdc/2 0 0 1 1 1 1 0 0

V2= Vdc/4 0 0 0 1 1 0 0 0

V1= 0 0 0 0 0 1 1 1 1

Vo(rms) = Vm/Root 2= 1.41v