离子源抑制极电源开关速度优化设计

抑制极电源是东方超环(Experimental Advanced Superconducting Tokomak,EAST)中性束注入(Neutral Beam Injection,NBI)束加速系统电源的重要组成部分,其输出端采用以多管串联的绝缘栅双极型晶体管(Insulated Gate Bipolar Transistor,IGBT)作为开关。IGBT开关的性能不仅关系到电源可靠性,也直接影响引出时离子束的光学特性。为满足高压引出电源与抑制极电源上升下降沿匹配的要求,提出了以电容反馈电路来控制IGBT开关速度的方案,采用Pspice软件对IGBT电容反馈进行建模,并进行了不同参数下的仿真,最后搭建了实验测试平台对方案进行了测试。测试结果表明:反馈电阻和反馈电容的大小对反馈电路效果的影响相反,当栅极电阻和反馈电阻取较大值,而反馈电容取较小值,通过调节反馈电阻的大小可以实现较大范围调节IGBT开通速度而又对关断速度影响较小。该优化方案可以达到抑制极电源IGBT开关性能的预期指标,且具有较高的可靠性。     

EAST强流离子源电源系统的初步测试运行

测试NBI大功率强流离子源的综合测试台正在建设,已研制了离子源等离子体发生器电源系统、等离子体电极高压电源及梯度极分压器、抑制极负高压电源等电源系统,以及高压传输线及缓冲器,在测试台上开展了对EAST中性束注入器第一台兆瓦级强流离子源样机进行整体电源系统测试和离子源起弧放电的初步测试,完成了离子源电源系统初步性能测试及...     

HL-2AMW级中性束注入系统弧流电源设计

中性束注入是磁约束受控核聚变实验装置中加热等离子体最有效的方法之一。针对中国环流器2号中性束大功率离子源的特点,从系统功能、主电路拓扑结构、控制硬件及控制时序等方面对弧流电源进行设计。整个电源由低位移相交流调压、高压隔离降压变压器、整流滤波和电流快速转移电路4部分组成。IGBT与电阻串联组成电流快速转移阵列电路,与离子源并联,可实现电流单次或多次快速转移、参数远程设定,有效用于强流离子束的引出和保护。选用DSP和CPLD电路技术实现低位与高位控制器。实验数据显示,该电源最大输出为200kW/1000A,纹波小于2％,开关上升下降时间达μs级。目前,该电源已安全运行3年,可靠性高,完全满足装置离子源及系统要求,也可应用于其它等离子体技术应用场合。     

基于Saber的5MW中性束注入弧电源仿真设计

强流离子源是HL-2M装置5 MW中性束注入加热系统的核心部件,离子源通过弧电源加速初级电子至高能态,碰撞气体分子,产生等离子体。所以,弧电源对于离子源维持稳定的弧放电非常重要。本文利用Saber软件建立了弧电源的主电路模型,设计并仿真了弧电流的恒流控制、打坑控制以及超级电容的恒流充电控制、恒功率放电控制等。这种方法不仅提高了弧电源电路的分析和设计效率,缩短了系统研制的周期,还可用于实际系统的故障分析和控制参数的整定,降低实验风险。实验结果表明,弧电源的真实输出与仿真输出结果相符。     

中性束注入器抑制极电源技术研究

中性束注入(NBI)器抑制极电源是中性束电源系统的组成部分,输出电压能根据实验情况在1~5kV内可调且脉冲式输出,脉冲波形的前后沿时间不大于20μs。采用串联谐振变换技术和移相脉宽调制技术设计高压直流平台,然后使用真空四极管进行调制,满足波形上的参数需要。对有关主电路和控制方法进行了分析说明。初步实验证明该设计调整性能好,抗过载与短路能力增强,能在脉冲负载状态下运行,具有较好的NBI实验应用前景。     

基于场畸变开关的Marx高压脉冲电源研制

针对脉冲电流法破碎核燃料球的研究需要,设计了基于Marx电路的高压直流脉冲电源。采用三电极场畸变开关作为触发开关,开关主电极和圆盘形触发极同轴布置,采用N2气体绝缘,仿真计算结果表明开关在充电和触发时电场最大值区域均匀,有机玻璃罩沿面场强符合绝缘要求。采用7级Marx发生器电路结构,每级由5 kΩ充电电阻,0.14"F高压脉冲电容和一个气体开关构成,触发源采用氢闸流管触发电路。进行了开关自击穿和Marx电路的触发实验,表明开关电感小,场畸变系数大,触发性能可靠。将该高压脉冲电源用于解体目标物质,可获得输出上升时间500 ns、电流峰值9.12 k A、单个脉冲持续时间3.5μs的高压脉冲,符合预期的设计指标。     

基于超级电容储能的中性束注入系统弧电源设计

弧电源是中性束注入加热系统中最关键的设备之一,它的性能决定了弧放电的稳定性及束流引出的品质。为提高弧放电稳定性,降低电网容量,减少对电网的冲击,弧电源拓扑设计采用了基于超级电容储能和开关电源技术的DC/DC变换器结构。利用多个IGBT功率模块并联工作,可提高电源工作频率,实现更快的动态响应速度。在详细分析电源工作过程的基础上,设计了滤波电路和电流快速转移电路,根据电源的要求和具体参数,由一阶RL电路的电流响应特性,精确计算出滤波电感的最小值。最后,利用Matlab对电源性能指标进行了仿真验证,结果表明电源性能完全符合设计要求。     

强流双潘宁离子源弧特性研究

针对22cm双潘宁离子源,研究了其弧流与放电调节参数的关系以及二次进气的效果,确定了拉长弧流脉宽、提高弧流强度与稳定性、达成离子源合适工作状态的措施,为获得高品质的弧流提供了依据.离子源弧特性测试研究结果对提高强流离子源的工作性能以实现NBI系统强流准稳态运行有重要的指导意义.     

离子源高压端信号取样测量电路的研究

在对离子源电参数进行测量时,由于现场环境较复杂,干扰源多,故对其高压信号取样隔离部分的抗干扰性能要求较高,其抗干扰性能好坏将直接影响测量结果的准确性.以测量离子源弧压为例,针对干扰特性设计了电阻、电容并联的分压取样电路,利用同轴电缆实现隔离屏蔽,利用差分方式进行信号采集输入以减小噪声干扰,使信号经取样隔离后具有较低的失...     

CSNS离子源引出电源关键技术研究

详细分析了中国散裂中子源(China Spallation Neutron Source,CSNS)直线加速器前端离子源引出电源工作原理,针对设计指标要求,提出了一种由40个功率MOSFET管串联组成的高压调制电路方案。在引出脉冲电源系统中对多个MOS管串联存在的问题,包括MOS管串联均压、保护电路、MOS管驱动信号一致性等关键问题进行了分析研究,并给出了有效的解决办法。最后在一台输入为AC220V、脉冲幅值25 k V、脉冲电流600 m A、平均功率为375 W输出的试验样机上验证了理论分析的正确性。经测试,实验结果表明离子源引出脉冲电源满足各项设计指标要求。     

Design and Development of a Power Supply System for NBI Test Stand of EAST

A neutral beam injector (NBI) test stand was constructed to develop a multi-megawatt prototype ion source as an auxiliary heating system on experimental advanced superconducting tokamak. A power supply system for the NBI test stand components such as a set of dc power supplies for plasma generator, a dc high voltage power supply of a tetrode accelerator, a transmission line and a surge energy suppressor. Stable arc discharges of the plasma generator with hydrogen gases for 100 s long pulse have been produced by six Langmuir probes feedback loop regulation mode to control the arc power supply. The 4 MW hydrogen ion beam of 1 s is extracted with beam energy of 80 keV and the beam current of 52 A. The dc high voltage power supply for the plasma grid of the prototype ion source was designed to contribute maximum voltage of 100 kV and current of 100 A. The high voltage power output is continuously adjustable to satisfy with plasma physics experiment in operation frequency of 10 Hz. To prevent damage of the beam source at high voltage breakdown, core snubber using deltamax soft magnetic materials have been adopted to satisfy the input energy into the accelerator from the power supply can be reduced to about 5 J in the case of breakdown at 80 kV. For the transmission line, a disc shape multi cable coaxial configuration was adopted and which the dimension of the diameter is 140 mm at the core snubber. The major issues of discharge characteristics with long pulse and beam extraction with high power for the prototype ion source were investigated on the NBI test stand.     

The Power Supply System of Ion Source for NBI

The power supply system of ion source for the Neutral Beam Injector (NBI) in the HT-7 superconducting tokamak is based on a single injector with one ion source that can deliver 700 kW of neutral beam power. Experiments and a discharges test on the ion source were successfully performed. In this paper, the circuit structures and features of every power supply are described and the results of the discharges test are presented.     

PIG Ion Source with Permanent Magnets: Model Based Anode Current Return Circuit

Ion sources are widely used in fusion technologies. A new high voltage pulsed power supply for use in penning ion gauge ion sources is proposed in this paper. To use discharge current, a diode-capacitor bank is included. The power supply is composed of 3 stages. A fast switching transistor is used as a single switch which is trigged by a pulse generator. A transformer is used to level up the voltage up to 2?kV without power loss. It is also used to isolate input and high voltage output. Also; the proposed high voltage power supply implementation uses a diode-capacitor bank whose capacitors are charged during plasma discharge. This system structure gives compactness and easiness to implement the total system which in combination with inexpensive commercially available components, makes the unit versatile and inexpensive.     

Experimental Results of Ion Beam Extraction of High-Current Ion Source for EAST Neutral Beam Injector

The first campaign of ion beam extraction tests are completed for EAST NBI high current ion source. The hydrogen ion beam with beam voltage of 80 keV is extracted from tetrode accelerator system. During the experiment, the characteristics of arc discharge and ion beam extraction are studied. The arc power reaches 120 kW and the extracted ion beam power reaches 3 MW. The relationship of some key parameters of arc and beam are investigated, and the details are described in this paper.     

混合模式低噪声3 kV高压直流电源设计

高压直流电源是电离室等核辐射探测器的关键部件。针对需要3 kV左右高压的电离室,本文研制了0～3 kV连续可调的低噪声、高效率、小体积及高稳定性的高压直流电源。该高压直流电源系统采用线性与开关混合模式设计,兼顾了转换效率与低噪声。核心部分升压转换部分采用线性罗耶谐振电路与高频变压器实现,保证足够低的高压电源输出纹波。罗耶谐振电路的供电电源则由边沿时间控制型超低噪声开关稳压器LT1534提供,从而实现了混合模式高压直流电源的设计。高压直流电源输出部分采用二阶RC滤波电路进一步降低了输出电压的纹波。实测输出电压范围为0～3 kV,静态功耗为0.4 W,3 kV输出时纹波为16.55 mV,由此可知该电源可用于低噪声的核辐射探测器供电场合。     

Design and control of the accelerator grid power supply-conversion system applied to CFETR N-NBI prototype

The acceleration grid power supply (AGPS) rated 200 kV/25 A is a key component devoted to supply the acceleration grids of the China fusion engineering test reactor negative-ion-based neutral beam injector (N-NBI) prototype system. This paper focused on the design and control of the AGPS conversion system (AGPS-CS), with emphasis on the requirement of the wide range output voltage and rise time. A voltage regulation switch at the front of step-down transformer is applied to optimize the grid current and DC-link voltage. Moreover, a new feedforward control strategy with piecewise PI compensator is proposed to improve the characteristics of AGPS. The simulation results of the proposed AGPS-CS are presented, proving the performance of the power supply to achieve the desired requirements.     

低能加速器开关电源研制

利用直流脉宽调制技术以及半桥变换电路,为一种低能电子直线加速器成功研制阳极开关电源。根据开关电源的特点,对该电源中低压和高压部分进行详细设计。低压部分采用SG1525A为控制核心,实现脉宽调制、软启动、稳压调节以及过压保护功能。该开关电源主要指标:输出电压0~800V,最大电流400 m A,工作频率为18.5 k Hz,纹波峰值系数为0.9‰,达到设计要求。