基于三谐振脉冲变压器的脉冲功率源研究

【作者】 李名加；

【导师】 许州； 常安碧； 金晓； 范植开；

【作者基本信息】 中国工程物理研究院 ， 核技术及应用， 2011， 博士

【摘要】 三谐振脉冲变压器是在空芯变压器的基础上引入第三级谐振电路形成的一种新型脉冲变压器,其最大的特点在于负载上的输出电压比空芯变压器高压绕组上的电压大的多(理论上最大可达2.77倍)。本文在国内首次对基于三谐振脉冲变压器的脉冲功率源进行了理论分析、工程设计和实验研究,提出了该类脉冲功率源的设计方法,并研制出一台基于三谐振脉冲变压器的脉冲功率源。首先,针对高变比空芯变压器次级锥形绕组电压分布不均可能导致绝缘击穿的问题,研究了锥形绕组的电压分布特性,为高变比空芯变压器及三谐振脉冲变压器的稳定运行提供了理论依据。采用“场—路”结合的思想,建立了多匝数变压器绕组电气参数有限元简化计算模型及等效多导体传输线(MTL)分析数学模型,运用有限元软件ANSYS计算电气参数有限元简化计算模型中的电路参数,然后将参数代入MTL模型求解从而得到锥形绕组的电压分布特性。计算结果与实验结果基本吻合,因此MTL模型可用于脉冲变压器锥形绕组冲击电压分布特性的理论分析和模拟计算。在此基础上,提出了锥形绕组电压分布改善措施并通过实验得到验证。然后,从基本电路理论出发,对空芯变压器及三谐振脉冲变压器电路进行分析,得出了理想状态下输出电压的表达式及三谐振脉冲变压器电路参数与回路三个固有频率的关系,并利用PSPICE软件进行电路模拟,分析了变压器参数、杂散参数及分布参数对变压器性能的影响。分析结果表明,不论是空芯变压器还是三谐振脉冲变压器,初级回路参数的影响都较大,在设计时要尽量减少初级回路电阻及初级回路杂散电感；对于三谐振脉冲变压器而言,因给定的负载电容为80pF,调谐电感的分布电容对三谐振脉冲变压器输出电压的影响很大,因此要尽量减小调谐电感的分布电容,此外,通过调节调谐电容和调谐电感的大小,可以调节三谐振脉冲变压器的输出状态。根据理论分析及电路模拟的结果,提出了适用于三谐振脉冲变压器的设计方法——迭代模拟法,并采用迭代模拟的方法在研制的空芯变压器基础上研制了一台基于三谐振脉冲变压器的脉冲功率源,进行了实验研究。实验结果表明,所研制的三谐振脉冲变压器输出电压的最大值最大可以达到锥形高压绕组输出电压的2倍,系统最大工作电压约为600kV,与理论分析的结果相吻合；与空芯变压器相比,虽然变压器能量传输效率没有提高,但是使用三谐振脉冲变压器使系统的功率容量增大,从而更多的能量可以通过空芯变压器传送到负载电容。实验和理论的结果都说明,将任意一台双谐振脉冲变压器改造成三谐振脉冲变压器具有可行性。更多还原

【Abstract】 The triple resonance pulse transformer is a new type of pulse transformer, which is based on air-cored transformer. The voltage appearing across the pulse transformer is significantly less than the output voltage; instead, the full output voltage appears across the tuning inductor. The max ratio of peak load voltage to peak transformer voltage is 2.77. In the paper the theoretical analyses, engineering design and experimental investigation of the pulse power generator based on the triple resonance pulse transformer is made and the design method is bring forward. Based on the design method a pulse power generator based on the triple resonance pulse transformer is developed.First of all, in order to solve the flashover problem between coils because of un-uniform of the voltage distribution along the air-cored transformer’s taper windings the voltage distribution of tapered winding is researched, which have theoretical and engineering significance for reliable and security operation of the air-cored transformer and triple resonance pulse transformer. Based on the idea of "field-circuit" association, multi-conductor transmission line (MTL) for tapered winding is bright forward. The distributed parameters of the MTL modle are obtained by use of the software ANSYS and then the distribution of the tapered winding can be gotten by solve the MTL model’s time domain equations. The calculation results accord with the simulation experiment results, that is to say, MTL model of the tapered winding can be used for calculating voltage distribution of pulse transformer’s taper winding. Based on the results, the methods to improve the distribution of the tapered winding are bring forwards by measuring and analyzing the voltage distribution of other taper windings with different structure.And then, by analyzing pulse transformer’s lossless circuit, the analytical expression for the output voltage and the relation of the triple resonance circuit parameters are presented. Variations of output voltage and energy efficiency to circuit component values, stray parameters and distributing parameters are discussed by use of the software Pspice. It is indicated that both air-cored transformer and triple resonance pulse transformer the primary parameters are much influential, and therefore the resistance and stray inductance of primary circuit must be reduced. As for the triple resonance pulse transformer, the distributed capacitance of tuning inductor affects the output voltage of the transformer very much because the load capacitance is 80pF, and therefore the distributed capacitance of tuning inductor must be reduced. In addition, the triple resonance pulse transformer’s output condition can be adjusted by tuning the tuning capacitor and the tuning inductor.According to the results of theoretic analysis and circuit simulation, the design method for the triple resonance pulse transformer is presented. By using the design methed—iterated simulation, a triple resonance pulse transformer is developed based on the developed air-cored transformer. The experimental results indicate that the ratio of the peak output voltage to the peak high voltage winding’s voltage is 2 and the peak output voltage of the triple resonance pulse transformer is 600kV. Comparing with air-cored transforme, the energy transmission efficiency of the triple resonance pulse transformer is not improved. However, the power capacity of the triple resonance pulse trnasfomrer is increased, and more energy can by transmitted to the load capacitor. All results indicte that a triple resonance pulse transformer can be developed based on a discretional double resonance pulse transformer.更多还原