The systematic mathematical analysis of the high frequency soft-switched AC-AC converter is proposed for variable frequency induction machine load in this paper. Both PWM and square-wave modes of operation have been c...The systematic mathematical analysis of the high frequency soft-switched AC-AC converter is proposed for variable frequency induction machine load in this paper. Both PWM and square-wave modes of operation have been considered. The frequency relation and phase unbalance problem due to discrete time integral half-cycle switching has been discussed in the beginning. Then, generalized Fourier series have been derived for output voltage, output current and supply current in two modes.The analytical results help to understand tbe converter characteristics, design optimally a convertermachine system of arbitrary capacity considering the various trade-off parameters.展开更多
基于广义状态空间平均法,利用脉冲频率调制-脉冲宽度调制(pulse frequency modulation-pulse width modulation,PFM+PWM)调制提供的双自由度提出一种可以同时调节输出电压以及实现开关器件主动软开关的控制策略,可以根据器件主体损耗情...基于广义状态空间平均法,利用脉冲频率调制-脉冲宽度调制(pulse frequency modulation-pulse width modulation,PFM+PWM)调制提供的双自由度提出一种可以同时调节输出电压以及实现开关器件主动软开关的控制策略,可以根据器件主体损耗情况“主动”切换软开关模式,兼顾整体效率提升与负载调节范围的扩展。分析全桥型串联谐振直流变换器工作频率高于谐振频率时的3种运行模式,并通过谐振腔参数设计避免特殊断续电流模式的发生;通过广义状态空间平均法建立包含调制环节在内的系统基波截断小信号模型,其数值扫频结果与物理模型展现出极高的精确度,并能精确反映拍频极点;定义反映多输入多输出系统能控程度的灵敏度矩阵,依据此设计实现输出电压调节及主动软开关的双链路线性控制策略。MATLAB/Simulink仿真及样机实验验证表明,所提控制相比传统脉冲频率调制具备更高的整体效率以及更宽的负载调节范围。展开更多
为了扩展双有源桥串联谐振变换器(dual active bridge series resonant converter,DABSRC)的软开关范围,提高变换器的稳定性,提出基于频域分析的变换器设计方法并建立其动态小信号模型。通过频域分析得到DABSRC的工作特性,利用工作特性...为了扩展双有源桥串联谐振变换器(dual active bridge series resonant converter,DABSRC)的软开关范围,提高变换器的稳定性,提出基于频域分析的变换器设计方法并建立其动态小信号模型。通过频域分析得到DABSRC的工作特性,利用工作特性设计变换器的电压增益、品质因数等参数;并针对实际系统中变换器需要闭环控制的问题建立DABSRC的动态小信号模型,为闭环控制的设计提供依据。通过搭建DABSRC的Matlab模型,验证分析方法及闭环控制的有效性。结果表明:基于频域分析的设计方法可以确保DABSRC在不同工况下实现软开关,同时,闭环控制可以显著提高变换器的稳定性。展开更多
文摘The systematic mathematical analysis of the high frequency soft-switched AC-AC converter is proposed for variable frequency induction machine load in this paper. Both PWM and square-wave modes of operation have been considered. The frequency relation and phase unbalance problem due to discrete time integral half-cycle switching has been discussed in the beginning. Then, generalized Fourier series have been derived for output voltage, output current and supply current in two modes.The analytical results help to understand tbe converter characteristics, design optimally a convertermachine system of arbitrary capacity considering the various trade-off parameters.
文摘基于广义状态空间平均法,利用脉冲频率调制-脉冲宽度调制(pulse frequency modulation-pulse width modulation,PFM+PWM)调制提供的双自由度提出一种可以同时调节输出电压以及实现开关器件主动软开关的控制策略,可以根据器件主体损耗情况“主动”切换软开关模式,兼顾整体效率提升与负载调节范围的扩展。分析全桥型串联谐振直流变换器工作频率高于谐振频率时的3种运行模式,并通过谐振腔参数设计避免特殊断续电流模式的发生;通过广义状态空间平均法建立包含调制环节在内的系统基波截断小信号模型,其数值扫频结果与物理模型展现出极高的精确度,并能精确反映拍频极点;定义反映多输入多输出系统能控程度的灵敏度矩阵,依据此设计实现输出电压调节及主动软开关的双链路线性控制策略。MATLAB/Simulink仿真及样机实验验证表明,所提控制相比传统脉冲频率调制具备更高的整体效率以及更宽的负载调节范围。
文摘为了扩展双有源桥串联谐振变换器(dual active bridge series resonant converter,DABSRC)的软开关范围,提高变换器的稳定性,提出基于频域分析的变换器设计方法并建立其动态小信号模型。通过频域分析得到DABSRC的工作特性,利用工作特性设计变换器的电压增益、品质因数等参数;并针对实际系统中变换器需要闭环控制的问题建立DABSRC的动态小信号模型,为闭环控制的设计提供依据。通过搭建DABSRC的Matlab模型,验证分析方法及闭环控制的有效性。结果表明:基于频域分析的设计方法可以确保DABSRC在不同工况下实现软开关,同时,闭环控制可以显著提高变换器的稳定性。