SU597024A1 - Short circuit current limiter - Google Patents

Description

(54) SHORT CIRCUIT CURRENT LIMITER

one

The invention relates to the field of voltage-sensing equipment, to devices designed to limit the short-circuit current without disconnecting.

Devices are known for limiting short-circuit current in high-voltage installations, for example, reactors.

The reactor is permanently connected to the circuit to be protected; therefore, the current density in it, in order to reduce electric power losses in a non-emergency mode, is chosen taking into account economic considerations. 3fo circumstance causes the metal intensity and considerable dimensions. However, the loss of electricity in these devices is still noticeable.

Some improvement is seen in the performance of the reactor obtained in the device is egfanichenny; short-circuit current, where, in the event of a short circuit in the circuit to be protected, the reactance of the protective device increases significantly. However, this improvement is achieved by

design complexity. The device is metal-intensive and in non-emergency mode requires electricity to cover losses.

The aim of the invention is a significant reduction in metal consumption and the elimination of electricity losses in the short circuit current limiter in normal mode.

The goal is achieved by the fact that a short circuit current limiter containing a resistor and a control system intended to be connected to the protected electrical circuit is supplied with a vacuumized capsule with a heat pipe. The connecting tube of this resistor is displaced and the heat pipe in the evaporator chamber is easily evaporated. shunt resistor in non-emergency mode.

Claims (2)

To automatically delay the return of condensate from the bridge metal to the evaporation chamber until the normal current mode is restored, the connecting tube of the heat pipe is heated by the hot resistor body at least to the temperature corresponding to the evaporation temperature of the bridge metal. The figure shows a short-circuit current limiter in the section. I Thermal smooth-walled pipe 1, contoured for thickness with a thick line, consists of an evaporation chamber 2 made of electrically insulating material with a metal bridge 3 located at the bottom, a connecting tube 4 and a condensation chamber 5. The connecting tube 4 is wound by a resistor 6 made of a refractory metal and electrically isolated from the connecting tube. The resistor is enclosed in a vacuumized 5 capsule 7, which allows heating to temperatures of non-ferrous metals. The leads of the floating bridge 8 are connected in parallel with the leads of the resistor 9 and embedded into the limiting electrical circuit. The short-circuit current limiter works as follows. In the absence of a short circuit, the current circuit closes through a metal bridge, the resistance of which is several orders of magnitude lower than the resistance of the resistor, when a short circuit current occurs, the bridge instantaneously evaporates under the action of heat caused by the flow of current, and this de-mutes the resistor. The latter limits the short circuit current to the circuit. The metal vapors, lifted by the connecting tube 4, fall into the condensation chamber 5, cooled in a known manner, for example, by blowing, i heat transfer from a strongly developed surface, etc.). In condensation; The metal is left to the chamber and if the temperature of the connecting tube reaches a level lower than the value corresponding to the evaporation temperature of the metal, the latter returns to the evaporation chamber 2 and re-shuns the resistor. If the short circuit current is maintained, then the hot body of the resistor will vaporize (the metal condensate and prevent it from returning to the evaporation chamber. Placing the limiter in vacuum will create a current density in the resistor during an emergency mode of several orders of magnitude than the prototype and shunting it eliminates the loss of electricity in a non-emergency mode and allows you to select a resistor that will provide short-circuit current limiting to any desired value. The reduction of metal consumption and the size of the limiter is required.In addition, the requirements for short-circuit current resistance of the equipment of the protected circuit are reduced. The limiter can be used as a short-circuit current limiter in switchgear devices of high voltage of any power. on the current-carrying part of the limiter, located in a vacuum, and in connection with this, reduces the building volume for Ms, reduces the power loss due to the actual output current limiter of the short circuit operation in the non-emergency period; provides requirements for the stability of the equipment since the limiter can limit the short-circuit current to any value. Claims A short-circuit current limiter comprising a resistor and a control system intended to be connected to a protected electrical circuit, is designed so as to reduce metal consumption and eliminate losses. electricity, it is equipped with a vacuum Capsule with a heat pipe, on the connecting tube of which the specified resistor is placed, and in the evaporation chamber of the heat pipe is placed easily evaporating metal, designed to shunt the resistor in emergency mode. Sources of information taken into account in the examination: 1. Zalessky A. M. High-Voltage Electrical Apparatus, p. 399-402, 1957. 2. USSR author's certificate number 408419, cl. And 02 H 9/02, 1971.