This paper proposes a new variable-mode control strategy that is applicable for LLC resonant converters operating in a wide input voltage range. This control strategy incorporates advantages from full-bridge LLC reson...This paper proposes a new variable-mode control strategy that is applicable for LLC resonant converters operating in a wide input voltage range. This control strategy incorporates advantages from full-bridge LLC resonant converters, half-bridge LLC resonant converters, variable-frequency control mode, and phase-shift control mode. Under this control strategy, different input voltages determine the different operating modes of the circuit. When the input voltage is very low, it works in a full-bridge circuit and variable frequency mode(FB_VF mode). When the input voltage rises to a certain level, it shifts to a full-bridge circuit and phase-shifting control mode(FB_PS mode). When the input voltage further increases, it shifts into a half-bridge circuit and variable frequency mode(HB_VF mode). Such shifts are enabled by the digital signal processor(DSP), which means that no auxiliary circuit is needed, just a modification of the software. From light load to heavy load, the primary MOSFET for the LLC resonant converter can realize zero-voltage switching(ZVS), and the secondary rectifier diode can realize zero-current switching(ZCS). With an LLC resonant converter prototype with a 300 W rated power and a 450 V output voltage, as well as a resonant converter with 20–120 V input voltage, the experiments verified the proposed control strategy. Experimental results showed that under this control strategy, the maximum converter efficiency reaches 95.7% and the range of the input voltage expands threefold.展开更多
A CMOS triode transconductor was developed with common mode feedback suitable for operating in low-voltage and low-power applications. The design is based on a body-driven input stage with feedback loops to extend bot...A CMOS triode transconductor was developed with common mode feedback suitable for operating in low-voltage and low-power applications. The design is based on a body-driven input stage with feedback loops to extend both the signal input range and the tuning capability. The effective transconductance of the body-driven triode stage is increased using a partial positive feedback technique which also partially solves the problem introduced by the small transconductance. This design uses the UMC 0.18 μm CMOS process. Simulations show the transconductor operated with 1 V supply voltage has less than -55 dB total harmonic distortions （THD） in the complete tuning range （0 V≤ Vcont≤ 0.43 V） for a 1 MHz 0.8 Vp-p differential input. The power consumption is 70 μW for a 0.43 V control voltage.展开更多
In high voltage input DC-DC converter, auxiliary winding of isolation transformer is usually used to supply power for control circuit. Due to the wide-range of input voltage, the variable output voltage of auxiliary w...In high voltage input DC-DC converter, auxiliary winding of isolation transformer is usually used to supply power for control circuit. Due to the wide-range of input voltage, the variable output voltage of auxiliary winding will cause a series of problems, such as variable drive pulse amplitude, increased driver switching devices loss and drive transformer core saturation. This paper analyzes the influence of variable output voltage of auxiliary winding in detail. A novel method is proposed to solve the problem of large variation range of auxiliary winding output voltage, which is adding a buck converter between the auxiliary winding and the control circuit. A dual switch forward convert has been designed with 300 V - 800 V input and 24 V/5 A output. The results show that this method is effective by comparing the different results of using buck converter or not.展开更多
文中提出一种集成可变母线的宽输入范围双有源全桥(dual active full bridge,DAB)变换器。与传统DAB变换器不同,所提变换器本质上是四开关Buck-Boost变换器与DAB变换器原边全桥进行复用,从而实现可变母线的构造与集成。通过调节可变母...文中提出一种集成可变母线的宽输入范围双有源全桥(dual active full bridge,DAB)变换器。与传统DAB变换器不同,所提变换器本质上是四开关Buck-Boost变换器与DAB变换器原边全桥进行复用,从而实现可变母线的构造与集成。通过调节可变母线的电压,可以在很宽的电压调节范围内实现电压匹配。同时辅助电感仅处理总功率的一部分并以连续导通模式工作,从而降低损耗并减小尺寸。所有开关均被证明可实现理论上的全负载范围零电压开关操作。此外,提出一种混合脉宽调制加相移调制控制策略来实现电压匹配控制并调节功率流;详细介绍其工作原理、工作特点和参数设计原则;最后,搭建一台1 k W实验室样机来验证理论分析。展开更多
基金Project supported by the National Natural Science Foundation of China(Nos.51177148 and 51407151)
文摘This paper proposes a new variable-mode control strategy that is applicable for LLC resonant converters operating in a wide input voltage range. This control strategy incorporates advantages from full-bridge LLC resonant converters, half-bridge LLC resonant converters, variable-frequency control mode, and phase-shift control mode. Under this control strategy, different input voltages determine the different operating modes of the circuit. When the input voltage is very low, it works in a full-bridge circuit and variable frequency mode(FB_VF mode). When the input voltage rises to a certain level, it shifts to a full-bridge circuit and phase-shifting control mode(FB_PS mode). When the input voltage further increases, it shifts into a half-bridge circuit and variable frequency mode(HB_VF mode). Such shifts are enabled by the digital signal processor(DSP), which means that no auxiliary circuit is needed, just a modification of the software. From light load to heavy load, the primary MOSFET for the LLC resonant converter can realize zero-voltage switching(ZVS), and the secondary rectifier diode can realize zero-current switching(ZCS). With an LLC resonant converter prototype with a 300 W rated power and a 450 V output voltage, as well as a resonant converter with 20–120 V input voltage, the experiments verified the proposed control strategy. Experimental results showed that under this control strategy, the maximum converter efficiency reaches 95.7% and the range of the input voltage expands threefold.
文摘A CMOS triode transconductor was developed with common mode feedback suitable for operating in low-voltage and low-power applications. The design is based on a body-driven input stage with feedback loops to extend both the signal input range and the tuning capability. The effective transconductance of the body-driven triode stage is increased using a partial positive feedback technique which also partially solves the problem introduced by the small transconductance. This design uses the UMC 0.18 μm CMOS process. Simulations show the transconductor operated with 1 V supply voltage has less than -55 dB total harmonic distortions （THD） in the complete tuning range （0 V≤ Vcont≤ 0.43 V） for a 1 MHz 0.8 Vp-p differential input. The power consumption is 70 μW for a 0.43 V control voltage.
文摘In high voltage input DC-DC converter, auxiliary winding of isolation transformer is usually used to supply power for control circuit. Due to the wide-range of input voltage, the variable output voltage of auxiliary winding will cause a series of problems, such as variable drive pulse amplitude, increased driver switching devices loss and drive transformer core saturation. This paper analyzes the influence of variable output voltage of auxiliary winding in detail. A novel method is proposed to solve the problem of large variation range of auxiliary winding output voltage, which is adding a buck converter between the auxiliary winding and the control circuit. A dual switch forward convert has been designed with 300 V - 800 V input and 24 V/5 A output. The results show that this method is effective by comparing the different results of using buck converter or not.
文摘文中提出一种集成可变母线的宽输入范围双有源全桥(dual active full bridge,DAB)变换器。与传统DAB变换器不同,所提变换器本质上是四开关Buck-Boost变换器与DAB变换器原边全桥进行复用,从而实现可变母线的构造与集成。通过调节可变母线的电压,可以在很宽的电压调节范围内实现电压匹配。同时辅助电感仅处理总功率的一部分并以连续导通模式工作,从而降低损耗并减小尺寸。所有开关均被证明可实现理论上的全负载范围零电压开关操作。此外,提出一种混合脉宽调制加相移调制控制策略来实现电压匹配控制并调节功率流;详细介绍其工作原理、工作特点和参数设计原则;最后,搭建一台1 k W实验室样机来验证理论分析。
