What are the reasons for the damage of the rectifier diode

What are the reasons for the damage of the rectifier diode

(1) Inadequate lightning protection and overvoltage protection measures.

The rectifier device is not equipped with lightning protection and overvoltage protection devices. Even if lightning protection and overvoltage protection devices are installed, their operation is unreliable and the rectifier diode is damaged due to lightning strikes or overvoltage.

(2) The operating conditions are harsh.

Indirect transmission generator sets, due to incorrect calculation of the speed ratio or the ratio of the diameters of the two belt discs not meeting the requirements of the speed ratio, cause the generator to operate at high speed for a long time, and the rectifier diodeto work at high voltage for a long time, promoting accelerated aging of the rectifier diode and premature breakdown and damage.

(3) Poor operational management.

The on duty operators are irresponsible in their work, unaware of changes in external loads (especially between midnight and 6am the next day), or fail to take timely action when a load shedding fault occurs outside, resulting in overvoltage and breakdown of the rectifier diode.

(4) The equipment installation or manufacturing quality is not up to standard.

Due to the long-term operation of the generator set under significant vibration, the rectifier diode is also subjected to external interference from this vibration; At the same time, due to the high and low speed of the generator set, the working voltage borne by the rectifier diode also fluctuates, greatly accelerating the aging and damage of the rectifier diode.

(5) The specifications and models of the rectifier diode do not match.

When replacing a new rectifier diode, mistakenly replacing the diode with one that does not meet the required working parameters or wiring errors can cause breakdown and damage to the rectifier diode.

(6) The safety margin of the rectifier diode is too small.

The overvoltage and overcurrent safety margin of the rectifier diode is too small, making it unable to withstand the attack of overvoltage or overcurrent transient peak in the generator excitation circuit and damage it.