Arc Modeling in Industrial Applications

Abstract

Simulation methods are routinely applied in the design and development process of power distribution devices. Arcing phenomena that occur during switching operations or fault events are modeled to optimize device performance and gain deeper insights into the behavior that testing cannot easily provide. In this contribution, some applications are presented in detail. The first example describes the distribution of debris that is generated inside a molded case circuit breaker (MCCB) during short-circuit interruption. A model is used to analyze the debris transport and to derive a solution to address issues caused by the debris. Second application example is a cooling device for hot plasma gases vented by circuit breakers. A model driven design process helps to define the device dimensions to achieve a safe temperature level of the exhaust gases. The third example deals with short-circuit behavior of a hollow core high voltage surge arrester, comparing model and experimental results.

From the molten bridge rupture to the local thermal equilibrium arc: optical emission spectroscopy of electric arcs during contacts opening

“…The simulation of arc dynamics in switching devices usually assume LTE conditions [1][2][3]. Since switching events in arc-based devices usually take at least a few ms, the fact that LTE is reached in the bulk of the plasma already 0.04 ms after molten bridge rupture confirms that this assumption is reasonable.…”

“…The local thermal equilibrium (LTE) approximation is a common assumption made when modeling electric arcs in low-voltage switching devices using magnetohydrodynamics methods [1][2][3]. While this approximation is usually verified in the bulk of the plasma, it is known to fail at providing a correct description of near-electrodes phenomena [4].…”

Model-based Optimization of the Switching Performance of a Switch Disconnector

“…Only one pole of SD is modeled, using a symmetry plane at the center of the pole. Computational fluid dynamics (CFD) and finite element analysis (FEA) meshes for different contact arm positions are prepared upfront and the motion of the contact is modeled, as described in [11]. For the initial contact position, CFD mesh and FEA mesh consist of 258k and 443k cells respectively, with average element size of 0.5 mm.…”

Transport and radiation properties of C4F7N-CO2 gas mixtures with added oxygen

“…(1) The LTE assumption might not be strictly valid close to the electrode walls and arc fringes, and (2) the accuracy of the model results are dependent on the accuracy of thermodynamic, transport and radiation properties. We would again refer the readers to our previous works [19,66] for additional CFD model related details.…”