Electrical Distribution Systems and Galvanic Protection

Electrical System Configuration

In this scheme, we utilize a double-entry system with detection to indicate the status of the current line. The detection is located in the isolator, which opens or closes based on the presence of current. If one line lacks voltage, the isolator opens; if both lines have tension, the system allows the passage of the line with the best rate.

The two lines are identical and feature a chopper-ground position with a marking indicating if the earth is connected. The grounded chopper is nestled at the normal section. The two lines meet, and this junction features an isolator with a fuse, connected to a grounded chopper with a plate. The grounded isolator is locked in the open position, followed by a measuring current transformer and a measuring voltage transformer with a cell door, covering points A, D, and F.

The line then divides into two equal parts, each containing a grounded isolator with a pilot signal indicating when the ground is connected. The grounded isolator is secured in the open position by a closure mechanism. Following this, we find a low-voltage measurement transformer and a battery charger. This charger is powered by either of the two lines and only operates when carrying current. The batteries provide power for ancillary services.

• Pilot before the chopper land: Capacitive voltage detection element.

Galvanic Corrosion Protection

The function of this process is to protect the galvanized metal surface. The most common galvanization involves depositing a layer of zinc (Zn) on iron (Fe). To avoid corrosion, it is critical to prevent contact between dissimilar materials with different oxidation potentials, which can cause galvanic corrosion. Caution must be taken to avoid this interaction.

Limiting Fuse Components

Limiting fuses are associated with switches and are held in pincer pressure to facilitate rupture.

Fuse Operation

Upon arrival of a short circuit, the fuse melts the internal sand, which turns into silicate and acts as an insulator. The silver element melts, the current passes through the resistive wire, and the hammer triggers to disconnect the fuse.

Autovalvular Lightning Rods

The autovalvular lightning rod consists of an element joining the line to internal varistors connected to the ground. It also features a component connected to the grounded tower. Within this, an explosive element is housed to isolate the tower ground if necessary. Key characteristics include:

• Discharge capacity: Approximately 10 kA.
• Residual Voltage: Evaluated at 10 kA.
• Leakage Current: <10 micro-amps.
• High Current Rating: >10 kA.