SINGLE PHASE FULL BRIDGE INVERTER

A single phase bridge DC-AC inverter is shown in Figure below. The analysis of the single phase DC-AC inverters is done taking into account following assumptions and conventions.

1) The current entering node a in Figure 8 is considered to be positive.

2) The switches S1, S2, S3 and S4 are unidirectional, i.e. they conduct current in one direction.

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When the switches S1 and S2 are turned on simultaneously for a duration 0 ≤ t ≤ T1 , the the input voltage Vin appears across the load and the current flows from point a to b.

Q1 – Q2 ON, Q3 – Q4 OFF ==> ν o = Vs

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If the switches S3 and S4 turned on duration T1 ≤ t ≤ T2, the voltage across the load the load is reversed and the current through the load flows from point b to a.

Q1 – Q2 OFF, Q3 – Q4 ON ==> ν o = -Vs

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The voltage and current waveforms across the resistive load are shown in Figure below.

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