Model Predictive Control with Sphere-Decoding Algorithm for parallel-connected H-Bridges

This paper presents a Sphere-Decoding algorithm (SDA) Model Predictive Control (MPC) for a parallel-connected H-Bridges Power Supply (PS). The proposed converter topology faces the very high current peaks (tens of kiloamperes) required by Central Solenoid coils of the Divertor Tokamak Test (DTT) facility for nuclear fusion, quite unusual in industry applications. The choice of the control strategy aims at exploiting the very fast transient response of MPC over linear control schemes and the computational burden reduction of SDA. As a result, this approach is able to guarantee a low load current error tracking and an effective current sharing among H-Bridges, thus a proper plasma initiation and its magnetic confinement for tens of years. In order to implement the SDA-MPC, the mathematical model of the presented PS is firstly introduced and validated. Afterwards, the SDA-MPC performances are tested through simulations. Experimental tests are carried out on a Hardware-In-the-Loop test facility.