FOURIER SERIES BIPOLAR SQUARE WAVE SERIES

As a result, SHE-PWM can select the low frequency harmonic components need to be eliminated and reduce the harmonic distortion.

FOURIER SERIES BIPOLAR SQUARE WAVE SERIES

Fourier Series is used to determine the amplitude of any odd harmonic in the output signal whereas Newton-Raphson is used to solve the equation for finding switching angles. This research propose SHE-PWM as a low switching frequency strategy that uses Fourier Series and Newton-Raphson analysis to calculate the switching angles for elimination of harmonic distortion. Selective Harmonic Elimination Pulse-Width Modulation (SHE-PWM) is another control technique for inverters. On the other hand, bipolar switching compares triangular waveform with a reference signal. 3 shows a bipolar square wave with variable angle and Fourier. The difference between unipolar and bipolar is there are two reference signals which are compared with the triangular waveform for unipolar switching. angle for square wave signals can be calculated using Fourier series analysis 21.

into its constituent sine wave harmonics by way of a Fourier Transform algorithm. Next, unipolar and bipolar techniques are using comparator to compare the reference voltage waveform with the triangular waveform. However, if a square wave is actually an infinite series of sine wave. The square wave type inverter produces output voltage in square shape which has simple logic control and power switches. By Fourier analysis, however, every periodic wave, even a square wave, is the summation of some series (often infinite) of sine waves.

Thus, there are a variety of controls techniques have been implemented for inverters switching such as square wave, SHE-PWM, unipolar and bipolar. The square wave may be represented by f(t) 8 <: ВЎ1 for ВЎ 1 2 T t < 0, +1 for 0 t < 1 2 T. For the simulations of the Walsh analysis a 1.5 kHz bipolar square wave input stimulus. Express the square-wavefunction illustrated in the gure below as a Fourier series. However the major issue that will reduce the inverter performance is the harmonic distortions that contribute to power losses. Walsh and Fourier transform results for PCM waveform BEA75. The performance of inverter has become a vital role in contributing effective power system nowadays.

Fourier series bipolar square wave