Sinusoidal PWM (SPWM) technique in Power Electronics - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define the carrier wave frequency in SPWM.

Power Electronics

carrier_frequency = [1]  # Frequency of the triangular carrier wave

Drag options to blanks, or click blank then click option'

A1000

B50

C5000

D60

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing the output frequency instead of the carrier frequency.

The carrier frequency in SPWM is typically high, often around 1 kHz or more, to allow smooth modulation of the output waveform.

2fill in blank

medium

Complete the code to calculate the modulation index in SPWM.

Power Electronics

modulation_index = [1] / carrier_amplitude  # Ratio of reference to carrier amplitude

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Acarrier_amplitude

Breference_amplitude

Coutput_voltage

Dfrequency_ratio

Attempts:

3 left

💡 Hint

Common Mistakes

Using carrier amplitude as numerator instead of denominator.

The modulation index is the ratio of the reference (sinusoidal) amplitude to the carrier (triangular) amplitude.

3fill in blank

hard

Fix the error in the code that generates the SPWM signal.

Power Electronics

spwm_signal = 1 if reference_signal > [1] else 0

Drag options to blanks, or click blank then click option'

Acarrier_signal

Boutput_voltage

Cmodulation_index

Dreference_signal

Attempts:

3 left

💡 Hint

Common Mistakes

Comparing reference_signal to itself instead of carrier_signal.

In SPWM, the reference sinusoidal signal is compared to the carrier triangular signal to generate the PWM pulses.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension that maps angles to SPWM values.

Power Electronics

spwm_map = {angle: 1 if [1] > [2] else 0 for angle in range(0, 360)}

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Amath.sin(math.radians(angle))

Bmath.cos(math.radians(angle))

Ccarrier_wave_value

Dmodulation_index

Attempts:

3 left

💡 Hint

Common Mistakes

Using cosine instead of sine for the reference signal.

The sinusoidal reference is the sine of the angle, compared to the carrier wave value to decide the PWM output.

5fill in blank

hard

Fill all three blanks to generate SPWM pulses with modulation index control.

Power Electronics

spwm_output = {angle: 1 if ([1] * [2]) > [3] else 0 for angle in range(0, 360)}

Drag options to blanks, or click blank then click option'

Amath.sin(math.radians(angle))

Bmodulation_index

Ccarrier_wave_value

Dmath.cos(math.radians(angle))

Attempts:

3 left

💡 Hint

Common Mistakes

Using cosine instead of sine.

Not multiplying by modulation index.

The SPWM output is generated by multiplying the sine of the angle by the modulation index and comparing it to the carrier wave value.