Analysis of Internal and External Bypass Circuit Design for ITER Poloidal Field Converter System

This paper describes the bypass circuit design applied to International Thermonuclear Experimental Reactor (ITER) poloidal field converter system. In the baseline design, an internal bypass scheme was designed for purposes of quench protection and reactive power reduction by bypass operation. However, due to the potential risks that exist in case of fault protection, internal bypass scheme is abandoned finally and external bypass scheme is proposed to replace the internal bypass design. In this paper, the weakness of internal bypass design has been reviewed and the reliability of external bypass design at different sites is analyzed. Simulations based on SIMULINK are performed to confirm the reasonability and availability of external bypass proposals.