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为实现一种结构简单、控制方便、高效率、高功率密度的逆变器,提出了一种新型谐振直流环节软开关逆变器的拓扑结构。通过在传统硬开关逆变器的直流环节添加辅助谐振单元,使直流母线电压周期性地归零,可以实现逆变桥主开关器件的零电压开关,而且辅助开关器件可以实现零电流开通和零电压关断。此外,其辅助谐振单元只有一个辅助开关器件,所以该逆变器控制相对简单,硬件成本低。对其工作原理进行分析,给出不同工作模式下的等效电路图和软开关的实现条件。制作一个1kW的实验样机,通过实验结果验证该软开关逆变器的有效性。 相似文献
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为改善逆变器的运行效率,提出了一种节能型三相谐振直流环节软开关逆变电路,在直流环节增设了辅助电路.当主开关需要切换时,提前使辅助电路进入谐振状态,将直流环节电压变化到零,保证主开关完成零电压软切换,并且辅助开关也能完成软切换.通过控制辅助开关切换的间隔时间来调节直流环节电压保持为零的时间,使逆变器能根据需要来调整脉宽调制策略.详细说明了电路的工作过程.实验结果表明逆变器主开关和辅助开关能完成软切换.因此,该拓扑结构对于研发高性能谐振直流环节逆变器具有借鉴意义. 相似文献
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为使中小功率三相逆变器实现在高开关频率下的节能运行,首次提出了一种新型三相谐振直流环节逆变器拓扑结构.设置在逆变器直流环节的辅助电路参与换流过程时,桥臂输入端的直流环节电压能周期性形成零电压状态,主开关和辅助开关都能完成零电压软切换.在高频金属氧化物半导体场效应晶体管(Metal Oxide Semiconductor Field Effect Transistor,MOSFET)作为该逆变器的开关器件时,实现零电压软切换能消除MOSFET的容性开通损耗,有利于优化逆变器效率.文中分析了电路的工作流程.2.5kW样机上的实验结果表明开关器件都处于零电压软切换.因此,该拓扑结构对于研发高性能的中小功率三相逆变器具有参考价值. 相似文献
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为了改善逆变器的性能,提出了一种辅助电路与主开关并联的单相全桥节能逆变器.逆变器采用受限单极式正弦脉宽调制(Sinusoidal Pulse Width Modulation,SPWM)方法,在每个开关周期,只需要控制1个主开关和1个辅助开关的切换,辅助开关可以采用固定占空比控制,而且不需要设定谐振电流阈值来控制辅助开关.在每个开关周期的换流过程中,需要切换的主开关所并联的谐振电容的电压能变化到零,主开关能实现零电压软开通.辅助电路中无器件直接串联在直流母线上,可有效降低辅助电路通态损耗.分析了电路工作原理,实验结果表明主开关和辅助开关都实现了软切换.因此该拓扑能有效降低开关损耗和提高逆变器效率. 相似文献
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作为中小功率发电系统重要环节的三相逆变器的开关频率增大时,开关损耗也显著增大,不利于节能。为实现中小功率三相逆变器的高频化和节能化,提出了一种三相零电压开关谐振极逆变器拓扑结构.当桥臂上的辅助谐振电路处于工作状态时,开关器件并联的电容的电压能周期性变化到零,使开关器件完成零电压软切换,这有利于高频金属氧化物半导体场效应晶体管(Metal Oxide Semiconductor Field Effect Transistor,MOSFET)作为逆变器的开关器件.分析了电路的工作流程,实验结果表明开关器件处于零电压软切换.因此,该拓扑结构对于研发高性能的中小功率三相逆变器具有参考价值. 相似文献
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中小功率单相全桥逆变器常以金属氧化物半导体场效应晶体管(Metal Oxide Semiconductor Field Effect Transistor,MOSFET)作为开关器件,为实现逆变器在高开关频率下的节能运行,本文提出了一种单相全桥节能型谐振极逆变器拓扑结构,其桥臂上分别并联相同的辅助谐振电路.桥臂上的主开关开通前,其并联的谐振电容的电压能周期性变为零,使主开关完成零电压软开通,可消除MOSFET的容性开通损耗,有利于逆变器的节能运行.本文分析了电路的工作模态,实验结果表明主开关器件处于零电压软切换.因此,该拓扑结构对于研发高性能的中小功率单相全桥逆变器具有参考价值. 相似文献
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为解决电流型脉冲宽度调制(Pulse Width Modulation,PWM)整流器在高开关频率下硬切换时的开关损耗问题,提出了一种电流型零电压开关节能整流器,其辅助谐振电路位于直流环节,且与直流母线并联,只有1个辅助开关.在换流过程中,主开关能实现零电压切换,辅助开关能实现零电流切换,而且当整流器采用多电平PWM控制策略时,辅助电路在每个开关周期只需工作1次.分析了谐振换流过程,仿真结果表明特征仿真波形符合理论分析,开关器件切换时处于软开关状态,整流器能平稳运行.该电流型零电压开关节能整流器可以在高开关频率和大功率的应用场合实现高效率运行. 相似文献
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ABSTRACT In order to realise the energy-saving operation of the three-phase inverter, a three-phase resonant DC link inverter with soft-switching function is proposed. The auxiliary resonant circuit on the DC side participates in the commutation process, so that the DC link voltage can change to zero before the main switch on the bridge arm is switched. Therefore, the main switch can complete the zero-voltage soft-switching and realise the energy-saving operation of the inverter by reducing the switching power loss. The circuit workflow and parameter design rules in each switching period are analysed. As indicated from the experimental results, the switching device is in the soft-switching state when it is switched, and when the output power reaches the rated value of 2.5 kW, the efficiency of the prototype is 98.4%, which is higher than that of the same type of soft-switching inverters. Thus, the auxiliary resonant circuit structure has reference value for the research and development of energy-saving three-phase inverters. 相似文献
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ABSTRACTIn the paper, the novel topology of the resonant DC link three-level soft-switching inverter is proposed to reduce switching losses and improve the efficiency of three-level inverter at high switching frequency. Symmetrical auxiliary resonant circuits are set in the DC link of three-level hard-switching inverter. Moreover, the terminal voltage of the resonant capacitors between the DC buses periodically drops to zero via the resonance of auxiliary circuits. Furthermore, under such condition, the main switches of the three-level inverter would be operated, in order to achieve zero-voltage switching. Based on the equivalent circuits in different operating modes, the paper analyses the working process of the soft-switching inverter in detail. In addition, a 3 kW laboratory prototype of resonant DC link three-phase three-level soft-switching inverter is built. The experimental results show that the main switches and auxiliary switches of the inverter are operated under soft-switching conditions, and the efficiency is significantly improved compared with the three-level hard-switching inverter. Therefore, the proposed topology can effectively reduce switching losses and prove to be more practical in engineering. 相似文献
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Jih-Sheng Lai 《Industrial Electronics, IEEE Transactions on》1997,44(1):71-80
This paper summarizes recently developed soft-switching inverters and proposes two possible options for electric propulsion motor drive applications. The newly developed soft-switching inverter employs an auxiliary switch and a resonant inductor per phase to produce a zero voltage across the main switch, so that the main switch can turn-on at the zero-voltage condition. Both the auxiliary switch and the resonant inductor are operating at a fractional duty and, thus, are small in size as compared to the main inverter circuit components. Operation modes in a complete zero-voltage switching cycle for the single-phase soft-switching inverter are described in detail, with graphical explanations. The circuit operation was first verified by a computer simulation, and then further tested with a 1 kW single-phase and a 100 kW three-phase inverter. Both simulation and experimental results are presented to show the superior performance in efficiency improvement, EMI reduction and dv/dt reduction of the proposed soft-switching inverters 相似文献