Surges (voltage spikes) that can occur in the rectifiers and inverters of UPS (uninterruptible power supplies) are mainly caused by the following:

Cause of surge occurrence

Counter electromotive force : Surges can occur due to counter electromotive force generated when power is cut off from fluorescent lamp ballasts or other electrical devices during a power outage.

Input transformer tripping : Surge voltage occurring when the input transformer inside the building is tripped.

Switching noise : High-frequency noise generated from the switching operation of the inverter.

CPU malfunction : The surge is recognized as a CPU clock signal, causing a momentary malfunction.

SCR malfunction : A malfunction occurs when a momentary pulse is applied to the gate voltage of the SCR (Silicon Controlled Rectifier) ​​for switching.

way out

Install surge protection devices (SPDs) : Install surge protection devices on the input and output lines of the UPS to block voltage spikes.

Use of filters : Eliminate electrical noise on input and output lines using EMI filters.

Strengthening the snover circuit : Reinforce the capacitor capacity of the snover circuit to reduce the switching noise of the inverter.

Use shielded wiring : Separate data lines and power lines with shielded wiring to minimize noise interference.

Regular inspection : Regularly inspect the main components inside the UPS (IGBT, SCR, capacitors, etc.) and replace worn-out parts.

These methods can help you increase the stability of your UPS and prevent problems caused by surges.