The four-level active neutral point clamped(ANPC)inverter has become increasingly widely used in the renewable energy indus-try since it offers one more voltage level without increasing the total number of active swit...The four-level active neutral point clamped(ANPC)inverter has become increasingly widely used in the renewable energy indus-try since it offers one more voltage level without increasing the total number of active switches compared to the three-level ANPC inverter.The model predictive current control(MPCC)is a promising control method for multi-level inverters.However,the conven-tional MPCC suffers from high computational complexity and tedious weighting factor tuning in multi-level inverter applications.A low-complexity MPCC without weighting factors for a four-level ANPC inverter is proposed in this paper.The computational burden and voltage vector candidate set are reduced according to the relationship between voltage vector and neutral point voltage balance.The proposed MPCC shows excellent steady-state and dynamics performances while ensuring the neutral point voltage balancing.The efficacy of the proposed MPCC is verified by simulation and experimental results.展开更多
In medium voltage-high power(MV-HP)applications,the high switching frequency of power converter will result in unnecessary energy losses,which directly affect efficiency.To resolve this issue,a novel finite control se...In medium voltage-high power(MV-HP)applications,the high switching frequency of power converter will result in unnecessary energy losses,which directly affect efficiency.To resolve this issue,a novel finite control set-model predictive control(FCS-MPC)with low switching frequency for three-level neutral point clamped-active front-end converters(NPC-AFEs)is proposed.With this approach,the prediction model of three-level NPC-AFEs is established inα-βreference frame,and the control objective of low average switching frequency is introduced into a cost function.The proposed method not only achieves the desired control performance under low switching frequency,but also performs the efficient operation for the three-level NPC-AFEs.The simulation results are provided to verify the effectiveness of proposed control scheme.展开更多
本文主要探讨了大功率三电平应用中3.3 kV SiC MOSFET和IGBT的混合应用问题,针对外管高频、内管低频的调制策略中不同箝位管脉冲时序对三电平有源中点箝位(ANPC)拓扑换流路径、开关损耗以及开关特性等关键因素的影响开展分析,实验验证...本文主要探讨了大功率三电平应用中3.3 kV SiC MOSFET和IGBT的混合应用问题,针对外管高频、内管低频的调制策略中不同箝位管脉冲时序对三电平有源中点箝位(ANPC)拓扑换流路径、开关损耗以及开关特性等关键因素的影响开展分析,实验验证了不同箝位管脉冲时序对SiC MOSFET和IGBT的动态特性和开关损耗的影响。展开更多
碳化硅三电平有源中点箝位(silicon carbide three level active neutral point clamped,SiC 3L-ANPC)变换器在中压大容量应用中具有突出优势,但与传统两电平变换器相比,其杂散参数相对较多,高速开关瞬态中较高的du/dt、di/dt与多杂散...碳化硅三电平有源中点箝位(silicon carbide three level active neutral point clamped,SiC 3L-ANPC)变换器在中压大容量应用中具有突出优势,但与传统两电平变换器相比,其杂散参数相对较多,高速开关瞬态中较高的du/dt、di/dt与多杂散参数的综合作用,易引发严重的器件电压、电流过冲和振荡,增加开关损耗,制约器件功率处理能力。准确定量评估开关瞬态行为,对变换器的精细设计、运行调控、安全保护、EMI抑制、寿命预测等都至关重要。为此,该文在厘清SiC 3L-ANPC变换器瞬态换流机理的基础上,提出一种SiC 3L-ANPC电路开关瞬态解析建模方法,所建模型仅需计算数个特定时刻的电路状态就能准确预测SiC 3L-ANPC变换器的开关瞬态行为,大大减小了计算时间与计算量,且每个特定时刻均具有明确的物理意义,具有普适性。实验结果证明了提出的建模方法的有效性,瞬态过冲最大计算误差小于6%,且计算速度比电路建模仿真方法提高上百倍。基于该文研究成果,为SiC 3L-ANPC逆变器的过电压抑制提供了电路参数设计指导意见。展开更多
高速磁浮交通牵引变流器采用24 MVA背靠背三电平有源中点钳位拓扑,其中两台整流器和两台逆变器共用直流母线。该文分析整流侧和逆变侧在不同功率因数下中点电压(neutral point voltage,NPV)偏移机理及不同电压矢量对NPV的具体影响。据此...高速磁浮交通牵引变流器采用24 MVA背靠背三电平有源中点钳位拓扑,其中两台整流器和两台逆变器共用直流母线。该文分析整流侧和逆变侧在不同功率因数下中点电压(neutral point voltage,NPV)偏移机理及不同电压矢量对NPV的具体影响。据此,针对高速磁浮逆变器并联和串联两种模式,建立NPV偏移模型,得到在调制比和功率因数同时变化时NPV的可控区域。为在全速范围保证NPV平衡,提出一种基于平移调制波的协同控制策略。为减轻整流器功率因数和调制比对NPV的影响,采用一种具有相电压半波对称性的载波脉宽调制,并证明其具备NPV自平衡能力。仿真和硬件在环实验表明,所提策略具有NPV恢复到平衡状态所需时间短、可控范围大等优点,可在高速磁浮全速工况下保证NPV平衡。展开更多
传统两电平有源电力滤波器(active power filter,APF)由干功率开关耐压水平和载流能力的限制,难以实现对高压大容量非线性负载的谐波补偿。在高压大容量系统中,二极管钳位型三电平变换器得到了广泛的应用。对三电平APF进行研究,提出一...传统两电平有源电力滤波器(active power filter,APF)由干功率开关耐压水平和载流能力的限制,难以实现对高压大容量非线性负载的谐波补偿。在高压大容量系统中,二极管钳位型三电平变换器得到了广泛的应用。对三电平APF进行研究,提出一种母线电压闭环数字控制策略。在同步旋转dq坐标系下,将三电平APF母线电压控制系统分为电压外环和电流内环2部分。在电压外环中,采用自适应滤波器求出直流侧电压平均值,采用PI控制器产生有功指令电流维持直流侧电压恒定。在电流内环中,针对三电平APF直流侧中点电位不平衡问题,从空间矢量PWM调制方法的角度出发,对中点平衡问题进行仔细研究,提出一种简单的中点电压平衡控制策略,只需检测各相电流和中点电压波动的方向,对小矢量进行取舍实现APF中点电位平衡控制。实验结果表明了所提出算法的正确性和有效性。展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2022YFB4201602)the National Natural Science Foundation of China(Grant No.52002409).
文摘The four-level active neutral point clamped(ANPC)inverter has become increasingly widely used in the renewable energy indus-try since it offers one more voltage level without increasing the total number of active switches compared to the three-level ANPC inverter.The model predictive current control(MPCC)is a promising control method for multi-level inverters.However,the conven-tional MPCC suffers from high computational complexity and tedious weighting factor tuning in multi-level inverter applications.A low-complexity MPCC without weighting factors for a four-level ANPC inverter is proposed in this paper.The computational burden and voltage vector candidate set are reduced according to the relationship between voltage vector and neutral point voltage balance.The proposed MPCC shows excellent steady-state and dynamics performances while ensuring the neutral point voltage balancing.The efficacy of the proposed MPCC is verified by simulation and experimental results.
文摘In medium voltage-high power(MV-HP)applications,the high switching frequency of power converter will result in unnecessary energy losses,which directly affect efficiency.To resolve this issue,a novel finite control set-model predictive control(FCS-MPC)with low switching frequency for three-level neutral point clamped-active front-end converters(NPC-AFEs)is proposed.With this approach,the prediction model of three-level NPC-AFEs is established inα-βreference frame,and the control objective of low average switching frequency is introduced into a cost function.The proposed method not only achieves the desired control performance under low switching frequency,but also performs the efficient operation for the three-level NPC-AFEs.The simulation results are provided to verify the effectiveness of proposed control scheme.
文摘本文主要探讨了大功率三电平应用中3.3 kV SiC MOSFET和IGBT的混合应用问题,针对外管高频、内管低频的调制策略中不同箝位管脉冲时序对三电平有源中点箝位(ANPC)拓扑换流路径、开关损耗以及开关特性等关键因素的影响开展分析,实验验证了不同箝位管脉冲时序对SiC MOSFET和IGBT的动态特性和开关损耗的影响。
文摘碳化硅三电平有源中点箝位(silicon carbide three level active neutral point clamped,SiC 3L-ANPC)变换器在中压大容量应用中具有突出优势,但与传统两电平变换器相比,其杂散参数相对较多,高速开关瞬态中较高的du/dt、di/dt与多杂散参数的综合作用,易引发严重的器件电压、电流过冲和振荡,增加开关损耗,制约器件功率处理能力。准确定量评估开关瞬态行为,对变换器的精细设计、运行调控、安全保护、EMI抑制、寿命预测等都至关重要。为此,该文在厘清SiC 3L-ANPC变换器瞬态换流机理的基础上,提出一种SiC 3L-ANPC电路开关瞬态解析建模方法,所建模型仅需计算数个特定时刻的电路状态就能准确预测SiC 3L-ANPC变换器的开关瞬态行为,大大减小了计算时间与计算量,且每个特定时刻均具有明确的物理意义,具有普适性。实验结果证明了提出的建模方法的有效性,瞬态过冲最大计算误差小于6%,且计算速度比电路建模仿真方法提高上百倍。基于该文研究成果,为SiC 3L-ANPC逆变器的过电压抑制提供了电路参数设计指导意见。
文摘高速磁浮交通牵引变流器采用24 MVA背靠背三电平有源中点钳位拓扑,其中两台整流器和两台逆变器共用直流母线。该文分析整流侧和逆变侧在不同功率因数下中点电压(neutral point voltage,NPV)偏移机理及不同电压矢量对NPV的具体影响。据此,针对高速磁浮逆变器并联和串联两种模式,建立NPV偏移模型,得到在调制比和功率因数同时变化时NPV的可控区域。为在全速范围保证NPV平衡,提出一种基于平移调制波的协同控制策略。为减轻整流器功率因数和调制比对NPV的影响,采用一种具有相电压半波对称性的载波脉宽调制,并证明其具备NPV自平衡能力。仿真和硬件在环实验表明,所提策略具有NPV恢复到平衡状态所需时间短、可控范围大等优点,可在高速磁浮全速工况下保证NPV平衡。
文摘传统两电平有源电力滤波器(active power filter,APF)由干功率开关耐压水平和载流能力的限制,难以实现对高压大容量非线性负载的谐波补偿。在高压大容量系统中,二极管钳位型三电平变换器得到了广泛的应用。对三电平APF进行研究,提出一种母线电压闭环数字控制策略。在同步旋转dq坐标系下,将三电平APF母线电压控制系统分为电压外环和电流内环2部分。在电压外环中,采用自适应滤波器求出直流侧电压平均值,采用PI控制器产生有功指令电流维持直流侧电压恒定。在电流内环中,针对三电平APF直流侧中点电位不平衡问题,从空间矢量PWM调制方法的角度出发,对中点平衡问题进行仔细研究,提出一种简单的中点电压平衡控制策略,只需检测各相电流和中点电压波动的方向,对小矢量进行取舍实现APF中点电位平衡控制。实验结果表明了所提出算法的正确性和有效性。
