Fault current relief device and power system with overvoltage protection

Abstract

The invention discloses a fault current discharge device with overvoltage protection and a power system, wherein the fault current discharge device includes: a current collector for collecting the current of a power transmission line; a fault current release device, a fault current release device It includes a controllable switch, a discharge circuit and a protection circuit. One end of the controllable switch is connected to the transmission line, the other end is connected to one end of the discharge circuit, the other end of the discharge circuit is grounded, and the protection circuit is connected in parallel with the discharge circuit. When the voltage at both ends of the leakage circuit is greater than the preset voltage threshold, the protection action is performed; the controller is connected to the control terminal of the current collector and the controllable switch respectively, and is used for when the current of the transmission line is greater than the preset current threshold , to control the controllable switch to close, so that the leakage circuit performs the leakage work. The fault current discharge device with overvoltage protection can not only ensure that the fault can be removed safely and efficiently, but also ensure the safety of the discharge circuit itself.

Description

technical field [0001] The invention relates to the technical field of power systems, in particular to a fault current discharge device with overvoltage protection and a power system. Background technique [0002] With the development of my country's social economy, the power load has increased rapidly, the scale of the power grid has expanded rapidly, and the interconnection between regional power grids has become increasingly close. Although the rapid development of the power grid has greatly improved the power transmission capacity of the line, it has also led to a rapid increase in the short-circuit current level of the system. The short-circuit current has great harm to the safe and stable operation of the power system and the electrical equipment itself. Excessive short-circuit current may exceed the interrupting capacity of the circuit breaker, making it difficult to remove the fault in time. How to limit the short-circuit current in power system faults has always a...

AI Technical Summary

Problems solved by technology

When the FCL is connected in series in the line, the closing and breaking conditions of the circuit breaker may be more stringent;

[0005] 3) FCL will affect the automatic reclosing of the circuit breaker;

[0006] 4) The current-limiting reactance of FCL is connected in series to the line to suppress the short-circuit current, but it also affects the setting of the line overvoltage protection

When the power grid fails, if it cannot be dealt with in time, it may further expand the scope of the accident and cause greater losses

[0014] At the same time, this scheme does not consider the countermeasures that the bleeder bears more than its own short-circuit current

The bleeder resistor has its own threshold value that can bleed the maximum fault current. If this value is exceeded, the bleeder resistor will burn out and cause the bleeder to fail.

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