Understanding the Causes of Overvoltage in Electrical Systems

Understanding the Causes of Overvoltage in Electrical Systems

A.  Internal Causes:-

  1. Switching Surges: Switching surges occur when there is a sudden change in the electrical circuit, such as switching off a large load or opening/closing circuit breakers.

  2. Faults in the System: Faults such as short circuits or ground faults can cause overvoltage conditions by disrupting the normal flow of electricity in the system.

  3. Resonance Phenomena: Resonance can occur in electrical systems due to the interaction between inductive and capacitive elements. Under certain conditions, resonance can amplify voltages to levels higher than normal.

  4. Insulation Failure: The most common case of insulation failure in a power system is the grounding of conductor (i.e. insulation failure between line and earth) which may cause over voltages in the system.

B. External Causes:-

  1. Lightning Strikes: Lightning strikes are a common cause of overvoltage in electrical systems. The massive discharge of electrical energy during a lightning strike can induce high voltages in nearby power lines and equipment.

  2. External Factors: Environmental factors such as geomagnetic storms or electromagnetic interference from nearby sources can also induce overvoltage in electrical systems.