Protection against Traveling Waves

 Travelling waves in power systems are high-frequency transient voltage or current surges that propagate along transmission lines and can cause significant damage to electrical equipment if not properly managed.

These waves are often caused by lightning strikes, switching operations, or sudden faults. Effective protection against travelling waves involves several strategies and devices.

1. Surge Arresters: Surge arresters, such as metal oxide varistors (MOVs) or silicon carbide arresters, are installed at key points in the system to divert the surge energy to the ground.

2. Ground Wires and Shield Wires: Ground wires, also known as shield wires or earth wires, are installed above transmission lines to intercept lightning strikes and direct the surge energy safely to the ground.

3. Line Surge Arresters: Installed directly on transmission lines to protect against travelling waves by clamping the surge voltage and dissipating the energy.

4. Wave Traps and Line Tuners: Wave traps are used to block high-frequency communication signals from entering substation equipment. They also help in managing the travelling waves.

5. Shielding and Bonding: Proper shielding and bonding of cables and equipment can reduce the impact of electromagnetic interference caused by travelling waves.

6. Line Reactors and Inductors: These devices are used to limit the rate of rise of the surge current and to absorb some of the surge energy.

7. Capacitive Voltage Dividers: These devices help in distributing the voltage along the line and reduce the peak voltage seen by individual components.