Implementation of an ITER-relevant QP-based Current Limit Avoidance algorithm in the TCV tokamak

TL;DR

This paper demonstrates that solving a constrained quadratic optimization problem online can effectively implement a current limit avoidance system in a tokamak, enhancing safety for large superconducting devices like ITER.

Contribution

First experimental validation of a quadratic programming-based current limit avoidance method in a tokamak, suitable for real-time application in future reactors.

Findings

Effective current limit avoidance demonstrated in TCV experiments.

Method suitable for real-time control in ITER-like conditions.

Potential to improve safety and stability in large superconducting tokamaks.

Abstract

The problem of avoiding saturation of the coil currents is critical in large tokamaks with superconducting coils like ITER. Indeed, if the current limits are reached, a loss of control of the plasma may lead to a major disruption. Therefore, a Current Limit Avoidance (CLA) system is essential to operate safely. This paper provides the first experimental evidence that the online solution of a constrained quadratic optimization problem can offer a valid methodology to implement a CLA. Experiments are carried out on the Tokamak \`a Configuration Variable (TCV) at the Swiss Plasma Center, showing the effectiveness of the proposed approach and its suitability for real-time application in view of future reactors such as ITER.