The application areas of conventional push pull converters are limited because of high voltage stress of switches (twice of input voltage). This paper presents a novel zero voltage and zero current switching (ZCS)...The application areas of conventional push pull converters are limited because of high voltage stress of switches (twice of input voltage). This paper presents a novel zero voltage and zero current switching (ZCS) PWM push pull three level converter in which the voltage stress of switches is input voltage. With phase shifted modulation strategy, the leading switches can only realize zero voltage switching (ZVS), and the lagging switches can realize ZCS when block capacitor and block diodes are added. Using the strategy, the converter overcomes the drawbacks presented by the conventional push pull converter, such as magnetic aberration, large switch loss, and voltage spike on switches, so it can get higher efficiency, and a wider application area. The operating principle of the new converter is analyzed and verified on a 600 W, 50 kHz experimental prototype. Several zero voltage and zero current switching PWM push pull three level converters are proposed.展开更多
An equivalent corrugation pitch-modulated （ECPM） distributed feedback （DFB） semiconductor laser with two equivalently assisted phase shifts （EAPS） was theoretically studied and experimentally demonstrated. The s...An equivalent corrugation pitch-modulated （ECPM） distributed feedback （DFB） semiconductor laser with two equivalently assisted phase shifts （EAPS） was theoretically studied and experimentally demonstrated. The simulated results showed that the longitudinal photon density distribution of the ECPM ＋ EAPS DFB lasers was much more uniform than that of a sole ECPM DFB laser without EAPS, and the longitudinal spatial hole burning was therefore suppressed more effectively. The results of experiment showed that good single longitudinal mode operation was achieved, with side mode suppression ratio （SMSR） being over 35 dB, and the wavelength range was from 1,559.64 to 1,563.02 nm when the operation current was from 50 to 160 mA at the temperature of 25 ℃, and the SMSR increased to 46.29 dB when the injection current was 130 mA.展开更多
文摘The application areas of conventional push pull converters are limited because of high voltage stress of switches (twice of input voltage). This paper presents a novel zero voltage and zero current switching (ZCS) PWM push pull three level converter in which the voltage stress of switches is input voltage. With phase shifted modulation strategy, the leading switches can only realize zero voltage switching (ZVS), and the lagging switches can realize ZCS when block capacitor and block diodes are added. Using the strategy, the converter overcomes the drawbacks presented by the conventional push pull converter, such as magnetic aberration, large switch loss, and voltage spike on switches, so it can get higher efficiency, and a wider application area. The operating principle of the new converter is analyzed and verified on a 600 W, 50 kHz experimental prototype. Several zero voltage and zero current switching PWM push pull three level converters are proposed.
基金supported by the National Natural Science Foundation of China(61306068 and 61435014)the Natural Science Foundation of Jiangsu Province of China(BK20130585 and BK20140414)+1 种基金the National High Technology Research and Development Program(SS2015AA012302)the Applied Basic Research Project of Suzhou City(SYG201309)
文摘An equivalent corrugation pitch-modulated （ECPM） distributed feedback （DFB） semiconductor laser with two equivalently assisted phase shifts （EAPS） was theoretically studied and experimentally demonstrated. The simulated results showed that the longitudinal photon density distribution of the ECPM ＋ EAPS DFB lasers was much more uniform than that of a sole ECPM DFB laser without EAPS, and the longitudinal spatial hole burning was therefore suppressed more effectively. The results of experiment showed that good single longitudinal mode operation was achieved, with side mode suppression ratio （SMSR） being over 35 dB, and the wavelength range was from 1,559.64 to 1,563.02 nm when the operation current was from 50 to 160 mA at the temperature of 25 ℃, and the SMSR increased to 46.29 dB when the injection current was 130 mA.
