Title :
Frequency spectra of pulse-density modulated waveforms [of resonant invertors]
Author :
Calleja, Hugo ; Pacheco, Joel
Author_Institution :
Cenidet- Electronica, Cuernavaca, Mexico
Abstract :
The pulse-density modulation technique (PDM) has been used in resonant inverters because it maintains soft-switching for any output power level. Its major drawback is that subharmonics of the resonant frequency are generated. In this paper, the frequency spectra of PDM waveforms, as a function of the duty cycle and the load time constant, is investigated. The current is analyzed as an amplitude modulated waveform, and results for regular and nonregular PDM are obtained. It is shown that the nonregular PDM, with the highest number of partial sequences and the best symmetry, produces the lowest subharmonics
Keywords :
DC-AC power convertors; PWM invertors; harmonic distortion; power conversion harmonics; resonant power convertors; switching circuits; PDM waveforms; duty cycle; frequency spectra; load time constant; nonregular PDM; output power level; pulse-density modulated waveforms; resonant frequency subharmonics; resonant invertors; soft-switching; Capacitors; Coils; Leg; Permeability; Power generation; Pulse modulation; Resonance; Resonant frequency; Resonant inverters; Voltage;
Conference_Titel :
Power Electronics Congress, 2000. CIEP 2000. VII IEEE International
Conference_Location :
Acapulco
Print_ISBN :
0-7803-6489-9
DOI :
10.1109/CIEP.2000.891418
