Why are rectifier diodes damaged

What are the reasons for the damage of rectifier diodes? In fact, there are more than one reasons for the damage of rectifier diodes. It is necessary to judge the cause of the damage of rectifier diodes through various manifestations. So, in general, what are the reasons for the damage of rectifier diodes? Today, I have summarized for everyone:

1、 The specification and model of the rectifier diode do not match. When replacing a new rectifier diode, mistakenly replacing a diode with working parameters that do not meet the requirements or wiring errors can cause the rectifier diode to break down and be damaged.

2、 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 caused by 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 rapidly, which greatly accelerates the aging and damage of the rectifier diode.

3、 The operating conditions are harsh. Indirect transmission generator sets, due to incorrect calculation of the ratio of rotational speeds or the ratio of the diameters of the two pulleys not meeting the requirements of the ratio of rotational speeds, cause the generator to operate at high speeds for a long time, and the rectifier diode will also work at a high voltage for a long time, leading to accelerated aging of the rectifier diode and premature breakdown and damage.

4、 Poor operational management. The on duty operators are irresponsible in their work, not familiar with changes in external loads (especially between midnight and 6am the next day), or when there is a load shedding fault, the operators do not take corresponding actions in a timely manner, resulting in overvoltage and damage to the rectifier diode.

5、 The safety margin of rectifier diodes is relatively small. The overvoltage and overcurrent safety margins of rectifier diodes are too small, which makes them unable to withstand the peak values of overvoltage or overcurrent transient processes occurring in the generator excitation circuit and cause damage to the rectifier diodes.

6、 The lightning protection and overvoltage protection measures are inadequate. 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 may be damaged due to lightning strikes or overvoltage.

These six are the most common reasons for damage to rectifier diodes, with the first reason being the most frequent. Therefore, selecting the correct type of rectifier diode is the most important.