A single-phase inverter is fed from a 100 V dc source and is controlled using a quasi-square wave modulation scheme to produce an output waveform, v(t - Electrical Engineering NAT PYQs Based test 23: Power Electronics | ExamTest.live

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A single-phase inverter is fed from a 100 V dc source and is controlled using a quasi-square wave modulation scheme to produce an output waveform, v(t), as shown. The angle σ is adjusted to entirely eliminate the 3^{r d} harmonic component from the output voltage. Under this condition, for v(t), the magnitude of the 5th harmonic component as a percentage of the magnitude of the fundamental component is _______ (rounded off to 2 decimal places).

Correct Answer

19.9-20.2

Solution & Step-by-step Explanation

For the given Quasi square waveform, V_{n} = \frac{4 V _{s}}{nπ} cos (nσ) Given that, the magnitude of 3^{r d} harmonic component from the output voltage is zero i.e. V₃ = 0 V_{3} = \frac{4 V _{s}}{3 π} cos nσ = 0 \Rightarrow cos (3σ) = 0 \Rightarrow σ = π/6 The magnitude of the fifth harmonic component from the output voltage is, V_{5} = \frac{4 V _{s}}{5 π} cos \frac{5 π}{6} The magnitude of the fundamental harmonic component from the output voltage is, V_{1} = \frac{4 V _{s}}{π} cos \frac{π}{6} \frac{V _{5}}{V _{1}} = \frac{\frac{4 V _{s}}{5 π} c o s \frac{5 π}{6}}{\frac{4 V _{s}}{π} c o s \frac{π}{6}} = - 0.2 Now, the value of the magnitude of the 5th harmonic component as a percentage of the magnitude of the fundamental component is % \frac{V _{5}}{V _{1}} = 20%

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A single-phase inverter is fed from a 100 V dc source and is controlled using a quasi-square wave modulation scheme to produce an output waveform, v(t), as shown. The angle σ is adjusted to entirely eliminate the 3^{r d} harmonic component from the output voltage. Under this condition, for v(t), the magnitude of the 5th harmonic component as a percentage of the magnitude of the fundamental component is _______ (rounded off to 2 decimal places).

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