Transient Process of Stray Capacitance for PSM High Voltage Power System

At present, based on the features of Pulse Step Modulator (PSM) technology in high voltage power supply (HVPS) is applied to drive the auxiliary heating system in domestic and foreign Tokomak facility. Before design of PSM HVPS, it is necessary to consider the effect of stray parameter existed in HVPS on the dynamic process of HVPS and load. In this paper, based on PSM technology 50 kV HVPS have been completed which is built for EAST auxiliary heating system and the relationship between the stray capacitance and leakage impedance respectively existed in the oil isolation transformer and dry multi-secondary winding transformer is discussed. Finally a stray parameters electrical circuit model of HVPS is presented. At last, from the results of experiment,it is consistent with the results of simulation.     

Proposed high voltage power supply for the ITER relevant lower hybrid current drive system

In the framework of the EFDA task HCD-08-03-01, the ITER lower hybrid current drive (LHCD) system design has been reviewed. The system aims to generate 24 MW of RF power at 5 GHz, of which 20 MW would be coupled to the plasmas. The present state of the art does not allow envisaging a unitary output of the klystrons exceeding 500 kW, so the project is based on 48 klystron units, leaving some margin when the transmission lines losses are taken into account. A high voltage power supply (HVPS), required to operate the klystrons, is proposed. A single HVPS would be used to feed and operate four klystrons in parallel configuration. Based on the above considerations, it is proposed to design and develop twelve HVPS, based on pulse step modulator (PSM) technology, each rated for 90 kV/90 A. This paper describes in details, the typical electrical requirements and the conceptual design of the proposed HVPS for the ITER LHCD system.     

Charging System of ECRH High-Voltage Power Supply and its Control System

High-voltage power supply (HVPS) of Electron Cyclotron Resonance Heating (ECRI-I) for HT-7 and HT-TU is presently being constructed. The high voltage (100 kV) energy of HVPS is stored in the capacitor banks, and they can power one or two gyrotrous. All the operation of the chaxging system will be done by the control system, where the field signals are interfaced to programmable logic controller (PLC). The use of PLC not only simplifies the control system, but also enhances the reliability. The software written by using configuration software installed in the master computer allows for remote and multiple operator control~ and the status and data information is also remotely available.     

Design and Development of a Series Switch for High Voltage in RF Heating

Plasma is the fourth state of matter. To sustain plasma in its ionic form very high temperature is essential. RF heating systems are used to provide the required temperature. Arching phenomenon in these systems can cause enormous damage to the RF tube. Heavy current flows across the anode–cathode junction, which need to be suppressed in minimal time for its protection. Fast-switching circuit breakers are used to cut-off the load from the supply in cases of arching. The crowbar interrupts the connection between the high voltage power supply (HVPS) and the RF tube for a temporary period between which the series switch has to open. The crowbar shunts the current across the load but in the process leads to short circuiting the HVPS. Thus, to protect the load as well as the HVPS a series switch is necessary. This paper presents the design and development of high voltage Series Switch for the high power switching applications. Fiber optic based Optimum triggering scheme is designed and tested to restrict the time delay well within the stipulated limits. The design is well supported with the experimental results for the whole set-up along with the series switch at various voltage level before its approval for operation at 5.2 kV.     

High voltage power supplies for ITER RF heating and current drive systems

The RF heating and current drive (H&CD) systems to be installed for the ITER fusion machine are the electron cyclotron (EC), ion cyclotron (IC) and, although not in the first phase of the project, lower hybrid (LH). These systems require high voltage, high current power supplies (HVPS) in CW operation.These HVPS should deliver around 50 MW electrical power to each of the RF H&CD systems with stringent requirements in terms of accuracy, voltage ripple, response time, turn off time and fault energy. The PSM (Pulse Step Modulation) technology has demonstrated over the past 20 years its ability to fulfill these requirements in many industrial facilities and other fusion reactors and has therefore been chosen as reference design for the IC and EC HVPS systems.This paper describes the technical specifications, including interfaces, the resulting constraints on the design, the conceptual design proposed for ITER EC and IC HVPS systems and the current status.     

Reconstruction of -35 kV／200 kW HVPS for Test of Klystron Units in LHCD System

The paper introduces the -35 kV/200 kW high voltage power supply (HVPS) which is specially used to test klystron units in LHCD system. The new klystrons must be tested under high voltage level before operation and the old klystrons which have worked for a longtime must be exercised by HVPS in lower hybrid current drive (LHCD) system. As the former HVPS has some shortages in engineering design and operation design, the HVPS has to be modified and rebuilt by adopting new method and technology to solve existing bottle-neck problems.     

Experiment and Operation of a LHCD—35kV／2.8MW／1000s High—Voltage Power Supply on HT—7 Tokamak

A-35kV/2.8MW/1000s high-voltage power supply(HVPS) for HT-7 superconducting tokamak has been built successfully.The HVPS is scheduled to run on a 2.45 GHz/1MW lower hybrid current drive(LHCD)^[1] system of HT-7 superoonducting tokamak before the set-up of HT-7 superconducting tokamak in 2003.The HVPS has a series of advantages such as good steady and dynamic response,logical computer program controlling the HVPS without and fault,operationa panel and experimental board for data acquisition.which both are grounded distinctively in a normative way to protec the main body of HVPS along with its attached equipments from dangers.Electric power cables and other control cables are disposed reasonably,to prevent singals from magnetic interference and ensure the precision of signal transfer.This paper involves the experiment and operation of a 35kV/2.8 MW/1000s HVPS^[2] for 2.45 GHz/1 MW LHCD system.The reliability and feasibility of the HVPS has been demonstrated in comparison with experimental results of original design and simulation data.     

Commissioning and operation of 130 kV/130 A switched-mode HV power supplies with the upgraded JET neutral beam injectors

The design features, on-site testing, commissioning and operation are described of two new 130 kV/130 A HV power supply units serving four upgraded 130 kV/60 A positive ion neutral injectors (PINIs) on JET. Both units were factory tested at full power and pulse length into dummy resistive load. Following on-site installation, the factory tests were repeated. The transition from dummy-load testing to PINI operation required full integration of the HVPS within the overall JET control system, and rigorous testing of the co-ordinated actions and protections of all PINI power supplies (filament and arc for plasma source and negative suppression grid). The implementation of these functions is described. Extensive use was made of parasitic integrated test pulses, where the other PINIs could be operated normally, with the HVPS energised under full remote control together with the corresponding PINI plasma sources, but with the HVPS connected to dummy load. The amount of NB operation time dedicated to commissioning was thereby minimised, yet gave a high degree of confidence of readiness for HV energisation of the PINI, and first beam operation followed less than 24 h from HV connection to the PINI. The routine operating experience and performance, including load protection characteristics of the new HVPS units are also described.     

基于FPGA状态空间方程解算器的HIRFL-CSR电源控制器设计

兰州重离子加速器冷却储存环(HIRFL-CSR)磁铁电源控制系统迫切需要提高性能,为实现基于现代控制理论的复杂控制算法,设计了ARM+FPGA结构的数字电源控制器。在FPGA中,设计了全新的硬件状态空间方程解算器,对电源进行实时、高速的状态反馈控制。结果证明,控制器可很好地实现最优观测状态反馈闭环控制,且其动态响应速度、稳态精度、抗干扰性及鲁棒性均有很大的提高。     

基于脉冲步进调制技术的ECRH全固态阳极高压电源控制系统设计

电子回旋共振管是产生高功率毫米微波的真空电子器件,在可控热核聚变研究、雷达等领域中有重要的应用。针对可控热核聚变研究中1 MW/105 GHz回旋管加热系统阳极电源幅度可调且调制的要求,使用高频开关电源技术和脉冲步进调制技术（PSM）研制了全固态阳极高压电源。重点阐述了阳极高压电源实现稳压、调制、前沿时间可调功能的软件控制算法,并通过实验对设计进行了验证。该阳极高压电源具有单脉冲、多脉冲调制和六电平预置波形等3种模式输出功能;输出参数达到35 kV/200 mA,波形前沿3 ms内可调,最大调制频率为1 kHz,调节精度在100 V以内。设计的控制方法也可应用于其他大功率微波源。     

ECRH系统中MOD控制系统的研究

负高压电源系统是电子回旋共振加热（ECRH）系统的重要组成部分,而MOD控制系统则是负高压电源系统乃至整个ECRH系统运行的关键。介绍了系统的理论背景和工作原理,并详细阐述了该控制系统的硬件结构和软件流程。实验运行表明,该系统运行稳定、控制正确、保护迅速可靠。     

ITER软X射线诊断系统电源设计

信号采集放大器是软X相机诊断系统的重要组成部分,以板卡的形式安装在PXI机箱内部以提高集成度。由于PXI机箱提供给放大器的电源质量差、噪声比较大,影响信号的采集。为了改善电源质量降低噪声,本文在PXI机箱电源的基础上对其进行优化,主要分析了电源阻抗及退耦设计;并有针对性的设计了电源EMI滤波器;对PCB电源层和地层进行谐振分析。实验测试结果表明,优化后降低了电源的噪声,提高了信号采集的质量。     

基于串行收发器的加速器电源数字控制器研究

为满足强流重离子加速装置（HIAF）对电源控制器多版本兼容和高精度控制性能的要求,研发了1套基于串行收发器的加速器电源数字控制器（APSDC）。该控制器采用基于总线互联的模块化设计架构,在保证加速器电源数字控制器高精度控制性能的前提下,兼具多版本兼容能力。设计了1套基于串行收发器的高速同步数据总线（HSB）用于数字控制器子板间数据通信,总线带宽达2 Gbps,且板间数据同步误差低于1 ns。电源上线运行实验结果表明,APSDC各项设计指标符合HIAF对电源的高精度控制及其他关键性能的技术要求,并具备较强的系统扩展性。     

EAST离子回旋加热系统高功率射频放大器阳极电源的研制

离子回旋共振加热是EAST超导托卡马克核聚变实验中重要的辅助加热手段。高性能的高功率射频放大器阳极电源对整个加热系统的稳定运行起重要作用。本工作设计了基于脉冲阶梯调制（PSM）技术的阳极电源及其控制保护系统,通过采集电源的实验数据对电源的设计进行了验证。实验结果证明,本阳极电源的设计和参数选择均是合理正确的,电源的开通和关断以及控制保护的数据指标完全达到设计要求。     

基于蚁群算法的小型铅基堆堆芯功率控制研究

小型铅基堆适用范围广、运行工况复杂多变,采用传统的控制方法难以实现堆芯功率的良好控制。为解决传统线性二次高斯控制（LQG）/回路传输恢复技术（LTR）控制器参数无法实现在线调整问题,采用微扰理论建立堆芯状态空间模型,设计一种基于蚁群算法的LQG/LTR控制器,建立小型铅基堆堆芯功率控制系统,实现了LQG/LTR控制器参数在线调整,并开展了堆芯动态仿真研究。结果表明,基于蚁群算法的LQG/LTR控制器相较于传统LQG/LTR控制器更易达到稳定,且变化幅值更小。      

基于国产化PXI模块的松脱部件监测系统软件开发

基于国产化PXI（面向仪器系统的PCI扩展）模块,利用中国核动力研究设计院（NPIC）研制的国产化松脱部件监测系统（LPMS）进行了16通道LPMS软件的开发,本文主要介绍了软件设计要求、设计原则、设计流程,以及主界面的设计,并重点对国产化PXI控制模块接口程序的软件实现进行了详细阐述。开发的基于国产化PXI模块的LPMS软件经测试满足设计要求,并已成功应用在出口国外某核电厂的LPMS中,为保障核电厂安全经济的运行起到了积极的作用。      

Development of a data acquisition and control system for the International Thermonuclear Experimental Reactor neutron flux monitor

To satisfy high-precision, wide-range, and real-time neutron flux measurement requirements by the International Thermonuclear Experimental Reactor(ITER), a data acquisition and control system based on fission chamber detectors and fast controller technology, has been developed for neutron flux monitor in ITER Equatorial Port #7. The signal processing units which are based on a field programmable gate array and the PXI Express platform are designed to realize the neutron flux measurement with 1 ms time resolution and a fast response less than 0.2 ms,together with real-time timestamps provided by a timing board. The application of the widerange algorithm allows the system to measure up to 10~(10) cps with a relative error of less than 5%.Furthermore, the system is managed and controlled by a software based on the Experimental Physics and Industrial Control System, compliant with COntrol, Data Access and Communication architecture.     

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.     

重离子加速器磁铁电源控制系统研制

重离子加速器通过一定周期的磁场对带电粒子进行约束,磁铁电源是产生所需磁场的关键部件,因此,要求磁铁电源控制系统具备高效性、稳定性、精确性。磁铁电源需按加速器运行周期进行响应运行。重离子加速器磁铁电源的时序必须严格按重离子加速器控制系统的控制时序进行控制。本工作研制了重离子加速器磁铁电源控制系统,通过磁铁电源控制器与同步时钟系统的通信进行控制时序的运行;通过与中央数据库的数据通信获取磁铁电源控制器所需的全部数据(如同步事例数据、波形数据等)。同步时钟信号一旦触发,磁铁电源控制器进行相应的数据获取并进行插值运算输出至磁铁电源进行控制。重离子加速器磁铁电源控制系统同步精度为1μs,实验平台测试控制器平台纹波精度为100ppm,能满足重离子加速器实验运行的要求。     

Progress in CFETR Power Stations Concept Study

While EAST experiment was running in 2012, the project of the China fusion engineering test reactor (CFETR) concept design was started. This ITER-like tokamak system will be the second full superconducting tokamak in China based on EAST technology. In phase I, it has 50–200 MW heat output for demonstrating power generation. The fusion power stations contain complete structure of fusion power plant (FPP) which do not appear in the ITER and huge HV substation which receives power from the 500 kV transmission grid for powering its pulsed power electric network (PPEN) and steady-state electric power network. Furthermore, its structure of turbine generator of FPP is similar to that of a nuclear power station of the pressurized-water reactor. This paper describes the typical CFETR loads and put forward the requirements of short circuit capacity of HV grid. It analyzes different strategies of putting the generator power to the grid, i.e. on the 500 kV grid for future DEMO power structure or 66 kV medium-voltage local grid for self-use. In period between twice burning plasma, conceptual solutions are presented to maintain thermal circuit operation.