võlakoormuse

Võlakoormuse, also known as "overvoltage" in English, refers to an electrical condition where the voltage in a circuit exceeds the specified rating for the equipment. This can occur due to various reasons such as faults in the power system, lightning strikes, or switching operations. Overvoltage can be categorized into two main types: temporary overvoltage and transient overvoltage.

Temporary overvoltage, also known as sustained overvoltage, lasts for a longer duration, typically from a few milliseconds to several seconds. This type of overvoltage can be caused by faults in the power system, such as short circuits or ground faults, which can lead to a rise in voltage levels. Temporary overvoltage can also result from the sudden disconnection of large loads, which can cause a sudden increase in voltage.

Transient overvoltage, on the other hand, lasts for a very short duration, typically from a few nanoseconds to a few milliseconds. This type of overvoltage is caused by sudden changes in the electrical system, such as switching operations or lightning strikes. Transient overvoltages can be further categorized into switching transients and lightning transients. Switching transients are caused by the operation of switches, circuit breakers, or other switching devices, while lightning transients are caused by lightning strikes.

Overvoltage can have serious consequences for electrical equipment, including damage to insulation, premature aging of equipment, and even complete failure. To protect against overvoltage, various protective devices are used, such as surge arresters, circuit breakers, and voltage regulators. These devices help to limit the voltage levels and protect the equipment from damage. Regular maintenance and inspection of electrical systems can also help to prevent overvoltage conditions.