What is Spwm modulation?
The modulation signal of SPWM is a sinusoidal waveform with a frequency equal to the desired output voltage frequency (50 or 60 Hz). In Figure 3, a simplified schematic of sinusoidal modulation is shown. The switching signal is generated by comparing the sinusoidal waveform and the triangular carrier waveform.
What are the different methods of Spwm pattern generation?
There are several techniques, among them: selective harmonic elimination (SHE) [8], space vector pulse width modulation (SVPWM) [9] and sinusoidal pulse width modulation (SPWM) [10] . Multi carrier SPWM technique is used to control multilevel inverter.
What is duty cycle modulation?
In electronics, duty cycle is the percentage of the ratio of pulse duration, or pulse width (PW) to the total period (T) of the waveform. Pulse-width modulation (PWM) is used in a variety of electronic situations, such as power delivery and voltage regulation.
What is the difference between Spwm and Svpwm?
The Sinusoidal Pulse Width Modulation and Space Vector Pulse Width Modulation are most widely used modulation techniques due to their greater advantages. The SVPWM technique gives higher level of fundamental voltage as compared to SPWM [1].
Which is an advantage of the SPWM technique?
SPWM technique for a three-phase inverter. In the SPWM technique, the switching frequency of an inverter is equal to that of a carrier wave. From Figs. 7.29 and 7.31, we can see that the switch is turned on/off once every period of the triangular carrier wave. Thus the SPWM technique has an advantage of having a constant switching frequency.
What kind of voltage reference is used in SPWM?
Typical SPWM technique uses a phase voltage reference as the pole voltage reference. On the other hand, different pole voltage reference can be used according to the PWM techniques.
How are switching states determined in a PWM?
Sinusoidal PWM is a typical PWM technique. In this PWM technique, the sinusoidal AC voltage reference v r e f is compared with the high-frequency triangular carrier wave v c in real time to determine switching states for each pole in the inverter. After comparing, the switching states for each pole can be determined based on the following rule:
Why is a higher switching frequency better For SPWM?
Frequency spectrum of the pole voltage for the SPWM. The higher the switching frequency is, the higher the order of the major harmonic is. Thus, when a higher switching frequency is used, the quality of the voltage waveform can be improved and filtering can be made easier.