How are voltage surges/transients generated?

• 15% of the main causes of voltage surges originating outside the system are lightning strikes and grid switching at high-voltage (230kV, 115kV) and medium-voltage (35kV, 15kV, 7kV) substations.
• 85% of the main causes of voltage surges originating within the system are load switching, opening or closing electrical switches, motor noise, electromagnetic interference, and static electricity, etc.

A common misconception is that the majority of high voltage surges originate outside the facility.
In reality, high-energy sources such as lightning strikes, grid switching, and other electrical faults typically account for only 10%-15% of all recorded transients.

In fact, over 80% of voltage surges generated within the system are almost all low-intensity and all propagate throughout the project’s power system as ring wave transients. Voltage surges are converted into oscillating cycles as they travel throughout the system due to the inherent impedance in the project’s electrical system construction. Without a good filter, these voltage surges will negatively impact sensitive electronic equipment because most transient surges will fall below the detection point of diodes and MOVs (metal oxide varistors), which are the main components used in commercially available Surge Protection Devices (SPDs).

Most transient surges we commonly see within systems range from 200 to 900 volts, and most are in the 200 to 400 volt range. This is the cumulative effect of internally generated voltage surges that degrades and shortens the lifespan of electronic equipment. These types of voltage surges can also cause malfunctions, shutdowns, and reprogramming issues in PLCs and other electronic devices.