Explain the function of a surge arrester in AC power systems.
1 Answer
A surge arrester, also known as a lightning arrester or transient voltage arrester, is an essential component in AC power systems designed to protect electrical equipment, devices, and infrastructure from transient voltage surges or spikes. These surges can be caused by lightning strikes, power switching events, or other sources of electrical interference. Surge arresters play a crucial role in maintaining the stability, safety, and reliability of AC power systems by diverting excessive surge currents away from sensitive equipment and into the ground.
The primary function of a surge arrester in AC power systems is as follows:
Surge Diversion: When a sudden and significant increase in voltage, such as a lightning strike, occurs in the power system, a surge arrester detects the rise in voltage and provides a low-resistance path for the excess surge current to flow to the ground. This diversion prevents the surge from reaching and damaging connected equipment.
Voltage Clamping: Surge arresters also help limit the voltage level that sensitive equipment is exposed to during a surge event. They act as voltage clamps, ensuring that the voltage across the protected equipment remains within safe limits. This prevents the equipment from experiencing voltage levels that could cause damage or malfunction.
Transient Suppression: Surge arresters not only protect against lightning-induced surges but also transient voltage spikes caused by internal events in the power system, such as switching operations or faults. By absorbing or dissipating the energy of these transient events, surge arresters prevent them from propagating through the system and affecting connected devices.
Maintaining System Integrity: By preventing damaging surges from traveling along power lines, surge arresters help maintain the integrity of the power distribution infrastructure. This, in turn, reduces the risk of outages, equipment damage, and the need for costly repairs or replacements.
Surge arresters are typically installed at points of entry for power lines into buildings or substations, as well as at various points within the power distribution network. They are designed to have a high voltage response, meaning they become conductive and shunt the surge current to the ground when the voltage across them exceeds a certain threshold. After the surge event subsides, the surge arrester returns to its high-resistance state, allowing normal power flow to resume.
It's important to note that surge arresters have a limited capacity to handle surge energy. If they are exposed to extremely high-energy events, they can degrade over time. Therefore, surge arresters may need to be periodically inspected and replaced to ensure their continued effectiveness in safeguarding AC power systems and the equipment connected to them.
The primary function of a surge arrester in AC power systems is as follows:
Surge Diversion: When a sudden and significant increase in voltage, such as a lightning strike, occurs in the power system, a surge arrester detects the rise in voltage and provides a low-resistance path for the excess surge current to flow to the ground. This diversion prevents the surge from reaching and damaging connected equipment.
Voltage Clamping: Surge arresters also help limit the voltage level that sensitive equipment is exposed to during a surge event. They act as voltage clamps, ensuring that the voltage across the protected equipment remains within safe limits. This prevents the equipment from experiencing voltage levels that could cause damage or malfunction.
Transient Suppression: Surge arresters not only protect against lightning-induced surges but also transient voltage spikes caused by internal events in the power system, such as switching operations or faults. By absorbing or dissipating the energy of these transient events, surge arresters prevent them from propagating through the system and affecting connected devices.
Maintaining System Integrity: By preventing damaging surges from traveling along power lines, surge arresters help maintain the integrity of the power distribution infrastructure. This, in turn, reduces the risk of outages, equipment damage, and the need for costly repairs or replacements.
Surge arresters are typically installed at points of entry for power lines into buildings or substations, as well as at various points within the power distribution network. They are designed to have a high voltage response, meaning they become conductive and shunt the surge current to the ground when the voltage across them exceeds a certain threshold. After the surge event subsides, the surge arrester returns to its high-resistance state, allowing normal power flow to resume.
It's important to note that surge arresters have a limited capacity to handle surge energy. If they are exposed to extremely high-energy events, they can degrade over time. Therefore, surge arresters may need to be periodically inspected and replaced to ensure their continued effectiveness in safeguarding AC power systems and the equipment connected to them.