Energy and Power Engineering, 2013, 5, 833-837

doi:10.4236/epe.2013.54B160 Published Online July 2013 (http://www.scirp.org/journal/epe)

Simulation of Fault Arc Using Conventional Arc Models

Ling Yuan, Lin Sun, Huaren Wu

School of Electrical and Automation Engineering, Nanjing Normal University, Nanjing, China

Email: 870599996@qq.com

Received April, 2013

ABSTRACT

Conventional arc models are usually used to research the interaction between switching arc and circuit. It is important to

simulate the fault arc for arc flash calculations, choice of electrical equipments and power system protection. This paper

investigates several conventional arc models for calculating the fault arcing current. Simulation results show that con-

ventional arc models can be used to simulate the fault arc if the parameters of arc models are given properly. This paper

provides the parameters of 5 popular arc models and describes the simulation results of the fault arc.

Keywords: Arc; Arc Flash; Arc Model; Plasma; Power System

1. Introduction

Short circuit in power systems is serious fault. The short

circuit current must be calculated for the choice of elec-

trical equipments and the setting of power system protec-

tion. An arc presents usually at the fault location in pow-

er systems. The fault arc could destroy electrical equip-

ment and threaten human life. It is important to calculate

the arc fault current for reducing loss.

An arc model must be used for calculation of the arc

fault current. There are a lot of arc models for describing

the arc. Arc models can be classified in three groups:

physical models, black box models and models based on

graphics and diagrams. Black box models describe only

the relation between input and output signals. Black box

models define the interaction between the arc and the

electrical circuit during the fault. In black box models,

the arc is described by one differential equation or sev-

eral differential equations relating the arc conductance

which describes the energy balance of the arc column.

Cassie arc model was presented by Cassie in 1939 [1].

Cassie assumed that the arc has a fixed temperature being

cooled by forced convection. This implies that the

cross-section area of the arc is proportional to the current

and that the voltage over the arc is constant. Cassie arc

model is suitable for arcs with high currents.

Mayr arc model was introduced in 1943 [2, 3]. Mayr

assumed that power losses are caused by thermal con-

duction and the arc conductance is dependent on tem-

perature. The cross-section area of the arc is assumed

constant. Mayr arc model is fit for currents near zero.

Schwarz developed a modified Mayr arc model in

1971[4]. The time constant and the cooling power in the

model are dependent on the arc conductance [5].

Habedank arc model is a series connection of a Cassie

and Mayr arc model [6]. It is suitable for arcs with high

currents and for currents near zero.

A modified Mayr arc model was presented in 1992 [7].

The cooling power in the model is current-dependent.

Schavemaker arc model is also a modified Mayr arc

model with a constant time parameter [8]. The cooling

power in the model is a function of the electrical power

input.

The above-mentioned arc models are black box mod-

els, that is, conventional arc models. They are usually

used to research the interaction between switching arc

and circuit during the interruption process of circuit

breakers. The characteristics of the fault arc are different

from that of the switching arc. This paper describes the

simulation methods of the fault arc using conventional

arc models. First of all the arcing fault was tested in the

high-power test laboratory and the arc voltage and the arc

current are depicted. Then 5 arc models are investigated

and their parameters are determined for simulation of the

fault arc. Conventional arc models can be used to simu-

late the fault arc.

2. Simulation of Fault Arc

Short circuit was tested in the high-power test laboratory.

The simplified laboratory test circuit is shown in Figure

1. The supply voltage is 400V.

The arc was initiated by means of a fuse wire between

2 electrodes. The arc voltage and the arc current were

recorded with the sampling frequency of 40 kHz and are

depicted in Figure 2. Figure 2 shows that arc voltage

and arc current are in phase and the arc is resistive. The

arc voltage ought to be represented for simulation the

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