Jännitteenvaihtelu

Jännitteenvaihtelu, also known as voltage fluctuation or voltage variation, refers to the unwanted deviations of the voltage from its nominal value in an electrical system. These variations can occur in both alternating current (AC) and direct current (DC) systems, though they are more commonly discussed in the context of AC power distribution. Jännitteenvaihtelu can manifest as sags (dips or undervoltages) or swells (surges or overvoltages), as well as more rapid fluctuations.

The causes of jännitteenvaihtelu are diverse. They can include sudden changes in load demand, such as the startup of large motors or the switching of heavy appliances, which can draw significant current and momentarily reduce the available voltage. Faults within the power grid, like short circuits or open circuits, can also lead to substantial voltage disturbances. Furthermore, the characteristics of the power generation and transmission infrastructure, including the impedance of the lines and the capacity of transformers, play a role. Intermittent renewable energy sources, such as solar and wind power, can also introduce variability into the grid voltage.

The effects of jännitteenvaihtelu can range from minor inconveniences to significant operational problems. Sensitive electronic equipment, including computers, medical devices, and telecommunications systems, can be susceptible to damage or malfunction due to voltage variations outside their operating tolerances. Motors may experience reduced performance or overheating. In some cases, severe voltage fluctuations can lead to equipment failure or premature aging. Mitigation strategies include voltage regulators, uninterruptible power supplies (UPS), and improvements in grid management and infrastructure.