The Effect of Amplitude Modulation Index and Frequency Modulation Index on Total Harmonic Distortion in 1-Phase Inverter

One of the problems that often arise in the conversion process using an inverter is the existence of Total Harmonic Distortion (THD). Harmonics is a symptom of sinusoidal wave formation whose frequency is a multiple of fundamental frequency. Harmonics will cause interference to the system to damage to electrical devices. This paper discusses the effect of modulation index value amplitudo ( M a ) and frequency modulation index ( M f ) of the value of THD before using the filter. The test was performed using a 1 phase inverter with input variation of the amplitude modulation index and the frequency that was set using PSIM software. The 16 ATMega microcontroller is used as a pulse width modulation (PWM) signal generator. Simulations using a 6 variations value Ma, ie 0.4, 0.6, 0.8 1.0, 1.2, and 1.4, as well as 10 variations of the value of M f , namely 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100. Based measurement, for M f are the same, the greater the value of M a , then the value of THD tends to decrease. Meanwhile, for the same M a , the greater the value of M f , then the value of THD tends to decrease.