[Background] The parameters and discharge level of the new generation of room temperature compact spherical ring fusion research device Xuanlong-50U upgraded and constructed by ENN Science and Technology Development Co.

Ltd. have been significantly improved. The maximum discharge current of the magnetic coil in the toroidal field of the device is up to 150kA. [Purpose] This article aims to conduct overall modeling and simulation research on the toroidal field power supply system

in order to ensure the safety and stability of the system under high parameter discharge experiments. [Methods] Xuanlong-50U real machine was selected as the research object. This article used parameter decoupling method to equivalently model the six-phase pulse generator and the phase-shifting transformer

and established the phase controlled rectification model considering phase lag and the time-varying load model for coil heating. Finally

a complete simulation model of the circumferential field power supply system was constructed. [Results] The simulation results under multiple discharge levels show that the constructed simulation model can accurately simulate the changes in electrical characteristics on site

with a simulation error of no more than 9.58% and waveform similarity of no less than 98.76%

meeting the accuracy requirements of on-site analysis. At the same time

it is proven that the system can operate stably according to the maximum design parameters

verifying the correctness of the initial design parameters of the power system. [Conclusions] The proposed simulation model can provide a simulation platform and data support for the setting of system protection schemes and verification of control strategies in subsequent unknown high parameter experiments.