The aviation ground power supply voltage stabilizing variable frequency power circuit is divided into three types according to the modulation method of the output waveform: PWM, PAM, and SPWM. Tianjin Rikate Aviation Equipment shares what components make up the modulation method?
The PWM circuit modulation method involves modulating the width of the pulse waveform. It primarily utilizes the switching characteristics of the inverter to chop and modulate the DC power source, achieving a constant U/t control as required. Compared to PAM circuit modulation, PWM circuit modulation has higher power efficiency, hence both produce an average voltage output in the form of a square wave.
PAM circuit modulation involves modulating the pulse amplitude of the output waveform. Its application is less frequent than PWM. Compared to PWM circuit modulation, PAM modulation offers noise-free driving with lower noise levels, but it has a lower power factor and a more complex circuit.
The SPWM circuit modulation method was developed to produce a sine wave output, as both PWM and PAM modulations result in square waveforms. The SPWM technique, which utilizes high-frequency pulse width modulation to generate higher-order harmonics that are easily filtered out, is the most reasonable modulation method and is commonly used in variable frequency power supplies.
