Correct short circuit operation method for current loop in bus protection, overhaul and maintenance

Abstract

The invention provides a correct short circuit operation method for a current loop in bus protection, overhaul and maintenance. The operation method comprises the following steps that: firstly, controlling a bus protection connecting sheet on a bus protection screen to be under an exiting state; then, determining the short circuit sequence of spaced current mutual inductors; according to the shortcircuit sequence, after four secondary side terminals of a bus protection screen terminal strip corresponding to each spaced current mutual inductor are subjected to short circuit ground connection,disconnecting four connecting strips on the independently corresponding bus protection screen terminal strip one by one, judging whether current values before and after disconnection change or not, and if the current values before and after disconnection change, carrying out regulation until the current values obtained before and after four independently corresponding connecting strips are disconnected do not change; and finally, waiting for entering a bus protection, overhaul and maintenance operation. By the implementation of the operation method, accidents in the prior art that body electric shock is caused due to an improper current loop short circuit operation method or the bus protection screen is subjected to fault-free tripping and the like can be overcome, and safety and reliability are high.

Description

technical field [0001] The invention relates to the technical field of substation maintenance, in particular to an operation method for correct short-circuiting of a current loop during busbar maintenance maintenance. Background technique [0002] Busbar protection inspection and maintenance is to isolate only the busbar protection that needs to be inspected and maintained during the continuous operation of the primary equipment of the power grid. However, due to the continuous operation of the primary equipment of the power grid, the secondary circuit of the interval current connected to the bus protection screen is still in normal operation. Therefore, it is necessary to short-circuit the current secondary circuit during the maintenance of the bus protection to avoid secondary side current The flow into the busbar protection screen will affect the busbar protection inspection and maintenance work. However, maintenance personnel, especially novices, during the short-circui...

AI Technical Summary

Problems solved by technology

If there is a problem with the short circuit between phase A and phase N, there is an open circuit in phase A, so that the interval 1 current transformer generates a high instantaneous voltage at both ends of the secondary winding of phase A, which can easily cause personal electric shock and other accidents

[0004] For another example, before the on-site staff short-circuits the secondary side A phase, B phase, C phase and N phase of the current transformer at interval 1, directly disconnect the secondary side of the current transformer corresponding to interval 1 on the terminal block of the bus protection screen. The connection piece of any one of the A phase, B phase and C phase on the secondary side makes the current entering the bus protection screen not a three-phase balanced current, which may easily cause the bus protection connection piece of the bus protection screen to trip under no fault conditions. Thus greatly affecting the busbar maintenance maintenance work

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