Research on Voltage Balance Control and Simulation of Chain-Type APF in High Magnetic Field

Steady-state magnetic field superconducting magnet power adopted double-inverse-star thyristor rectifier solutions, it is a typical non-linear load which will bring great reactive power impact and harmonic pollution at runtime. In this paper, according to the scheme of scientific facility chain-type high voltage active power filter (APF), a three-grade voltage balance control of capacitor method was proposed. Considering the non-linear characteristics of APF, we using fractional order PI controller instead of ordinary PI controller. The solution of fractional order calculus is realized based on the improved Oustaloup algorithm. Finally, the working effect of fractional order PI controller and ordinary PI controller are comparative analysis through simulation and experimental results, the results show that the DC voltage balance control strategy used in this paper is correct, and has a certain reference value.