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
三相脉宽调制(pulse-width modulation,PWM)整流器中,当电网电压不平衡时,传统的预测直接功率控制(predictive direct power control,PDPC)策略导致输入电流严重畸变,另外,网压传感器使整个系统变得更复杂,且耗费成本。为了改善PWM整流...三相脉宽调制(pulse-width modulation,PWM)整流器中,当电网电压不平衡时,传统的预测直接功率控制(predictive direct power control,PDPC)策略导致输入电流严重畸变,另外,网压传感器使整个系统变得更复杂,且耗费成本。为了改善PWM整流器输入电流质量,并降低系统成本,将基于改进型二阶广义积分器(second-order generalized integrator,SOGI)的无网压传感器算法与PDPC策略相结合,采用改进型二阶广义积分器产生同频率的正交信号,估算电网电压,实现无网压传感器PDPC。根据扩展pq理论分析电网不平衡情况下产生有功、无功功率二倍频振荡的原因,在此基础上推导出了消除功率振荡的整流器交流侧电压方程,进而通过空间矢量调制(space vector pulse width modulation,SVPWM)确定开关状态。在仿真平台对所提方法在电网平衡和不平衡情况下进行仿真,仿真结果表明,所提方法降低了不平衡电网对输入电流波形的影响,消除了功率二倍频振荡,准确估算电网电压,实现电网平衡和不平衡情况下的正常工作,通过对比这2种情况下的仿真结果,验证了该方法的有效性。展开更多
In predictive direct power control(PDPC)system of three-phase pulse width modulation(PWM)rectifier,grid voltage sensor makes the whole system more complex and costly.Therefore,third-order generalized integrator(TOGI)i...In predictive direct power control(PDPC)system of three-phase pulse width modulation(PWM)rectifier,grid voltage sensor makes the whole system more complex and costly.Therefore,third-order generalized integrator(TOGI)is used to generate orthogonal signals with the same frequency to estimate the grid voltage.In addition,in view of the deviation between actual and reference power in the three-phase PWM rectifier traditional PDPC strategy,a power correction link is designed to correct the power reference value.The grid voltage sensor free algorithm based on TOGI and the corrected PDPC strategy are applied to three-phase PWM rectifier and simulated on the simulation platform.Simulation results show that the proposed method can effectively eliminate the power tracking deviation and the grid voltage.The effectiveness of the proposed method is verified by comparing the simulation results.展开更多
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。
基金National Natural Science Foundation of China(Nos.51767013,52067013)。
文摘In predictive direct power control(PDPC)system of three-phase pulse width modulation(PWM)rectifier,grid voltage sensor makes the whole system more complex and costly.Therefore,third-order generalized integrator(TOGI)is used to generate orthogonal signals with the same frequency to estimate the grid voltage.In addition,in view of the deviation between actual and reference power in the three-phase PWM rectifier traditional PDPC strategy,a power correction link is designed to correct the power reference value.The grid voltage sensor free algorithm based on TOGI and the corrected PDPC strategy are applied to three-phase PWM rectifier and simulated on the simulation platform.Simulation results show that the proposed method can effectively eliminate the power tracking deviation and the grid voltage.The effectiveness of the proposed method is verified by comparing the simulation results.