Protection of Storage Batteries against Short-Circuit Currents in Alternative Power Systems

Abstract

Short circuit faults are the most dangerous modes for DC networks and for energy storage devices with rechargeable batteries. Therefore, highly effective protection of such objects becomes especially important and necessary. Switching off short-circuit currents in DC circuits is a more difficult task than in AC networks. This is due to the absence of a short-circuit current transition through zero in DC circuits. A mechanical switch is used to interrupt the short-circuit current. In parallel to its contacts, a circuit with an oscillating circuit is switched on. When the switch contacts are opened, current fluctuations occur with a point of zero value. This leads to an interruption of the short-circuit current. To increase the efficiency of switching off the short-circuit current, it is necessary to open the switch contacts in the shortest time after the occurrence of a short circuit. This article discusses the principles of constructing a relay protection device with maximum performance. The relay protection acts on the mechanical switch, which leads to the opening of its contacts. The principles of building high-speed protection and algorithms for its implementation are presented.