A study on medium voltage power conversion system for plasma torch

Abstract

This paper investigates the medium voltage power conversion system for plasma torch application. The plasma torch rated for 3MW, 2kA and having the physical size of 1m long is selected. The dynamic characteristics of the DC arc in plasma torch are investigated using advanced 3D magneto-hydrodynamics simulation. The parameters of Cassie-Mayr arc model are calculated based on 3D simulation. Two-phase staggered series connected 3-level dc/dc converters is proposed to be a suitable power converter topology. Simulation shows that the ripple of arc current can be maintained within ±11.5% of its rated value, 460A under the existence of load disturbance of ±10% in arc voltage. This power converter topology provides high ignition voltage around 5kV during ignition phase and high arc stability under the existence of intrinsic arc disturbance noise.

Analysis of electrical characteristics of the four-quadrant converter in high speed train considering pantograph-catenary arcing

“…Based on the traditional Mayr and Cassie arc models, this article uses a novel arc model, which is combined with the Mayr and Cassie arc models. Dai 29 and Suh et al 30 have determined a transition function considering the stability of the arc, but it cannot describe the low-current state of the arc due to the range of the function. To describe the characteristics of the arc, the author proposes the transition function (i), which changes with the current.…”

Medium Voltage Power Supply with Enhanced Ignition Characteristics for Plasma Torches

“…P 0 and α are functions of the arc current I a and the arc voltage U a . The arc parameters have been calculated by a number of steady and transient arc simulations [5], [6], [19]. The arc model described in Eq.…”

“…The plasma torch systems have an intrinsic electrical characteristic of negative dynamic resistance during steady-state operation [1]. Due to the dynamic characteristics of high enthalpy plasma flows and arc fluctuations, a plasma torch system generates an alternating disturbance input to the overall power conversion system [5], [6]. This alternating disturbance input together with the negative dynamic resistance characteristic occasionally leads to the extinguishment of a plasma arc unless properly stabilized by fast regulation of the arc current.…”

“…Pyrolysis incinerator employing a plasma torch in waste disposal system [16]. plasma torch itself in [5], [6].…”