Compact Electric Power System for Fusion Reactor
The issue of the Tokamak fusion reactor is its large area occupied by its power supply, which is about half of the total building area for the International Thermonuclear Experimental Reactor (ITER), together with the compatibility between the site grid and Tokamak loads during the plasma operation period. ITER is now implemented with Tokamak, which requires about 1 GVar reactive power to compensate its power system for superconducting magnets where about 0.2 GVar is transferred from France Electrical Power Network, the other 0.75 GVar is generated by the system of reactive power compensation and harmonic filtering, the standard VSC configuration. ITER can experimentally generate 500-MW fusion thermal power in 400 s long pulse mode. It could only generate about 500 MW/3 = 167 MWe active electric power if it is to be configured with pressured water reactor due to the fact that it is only about 1/3 conversion efficiency from thermal energy to electric energy. For such fusion machine, the requirement for reactive power is much larger than the active power it generates. Based on this requirement, one efficiency and compact pulsed synchronous generator is suggested for this purpose. It can generate not only the fundamental reactive power to compensate and stabilize the power network with low internal impedance but also the active power for outputting power to the network with exciting controller of the generator. Due to its two purposes in one device configuration, it becomes compact and reliable by being implemented in the design of future fusion power plant for demonstration. Some consideration has been done to the special low impedance synchronous generator, which is intended for the concept design of Chinese Fusion Engineering Testing Reactor, targeting the compact electric power system for superconducting Tokamak fusion reactor.
A single element multiphase compulsator powered railgun system
This paper investigates multiphase railguns (electromagnetic launchers) powered by multiphase compensated pulsed alternators (compulsators). The polyphase system offers several advantages over the single phase system. The multiphase compulsator relaxes the strong dependence between the current pulse width necessary for the railgun and the design parameters of the generator (number of poles, rotor diameter and tip speed) thus allowing the compulsator to be designed for optimum power density and electromechanical energy conversion. The paper examines in particular the two phase system. The authors explore different methods of achieving high acceleration ratios (average to peak) in multiphase railgun systems. Some of the methods analyzed are ramping up the field current of the compulsator to counter the increasing impedance of the gun, using a railgun with varying inductance per unit length (L'), and using an external variable inductor in series with the compulsator. Special attention is devoted to the external series inductor method which uses a rotary flux compressor (rfc). Several concepts to integrate the rfc and the compulsator into a single element device are discussed. Comparison between the state of the art single phase compulsator powered 9 MJ railgun system, currently under fabrication at CEM-UT and a two phase compulsator driven four rail railgun system is also presented. >
The magnet design of the SSRF storage ring and booster
The 3.5 GeV Shanghai Synchrotron Radiation Facility (SSRF) is designed to be a new generation of electron storage ring producing high brightness X-ray radiation from dipole magnets and insertion devices. The storage ring lattice, which has 20 DBA cells and 10 super-periods, comprises 40 dipoles, 200 quadrupoles and 140 sextupoles. The booster which is used to accelerate the 300 MeV beam from the linac to the 3.5 GeV operating energy of the storage ring has a simple FODO lattice structure, The booster ring lattice has 27 cells and 3 super-periods and comprises 84 dipoles, 54 quadrupoles and 36 sextupoles. This paper is concerned with all these magnets. The major design parameters and the optimized 2D multipole coefficients of these magnets are listed. The mechanical design and the fabrication procedures for the magnets are presented. Two prototypes of the storage ring dipole and the booster dipole with full scale will be finished by next March and the other four prototypes of quadrupoles and sextupoles for the two rings will be finished by the end of next year.