As the domestic market pays more and more attention to the development and application of power semiconductor, the citation rate of high voltage DC power supply is also increasing. Because many application environments of power semiconductor need to face high voltage, high current power conditions, so introduced high voltage DC power supply and high current DC power supply, high voltage up to 50kV, single current up to 50000A, to provide customers with accurate, convenient, intelligent testing conditions.

 

500kW load bank
 

In this paper, we will introduce the short circuit protection of high voltage DC power supply. Because the high voltage of high voltage DC power supply reaches 50kV, therefore, in the process of voltage test, short circuit protection and insulation resistance test is very important, it is to protect the safety of testing products and testers. High voltage DC power supply test object is mainly rechargeable battery. This is not your average household rechargeable battery, but the kind commonly used in high-voltage cables. In order to improve the voltage resistance and prolong the service life of the tested product, the short-circuit protection performance must be improved.

When the high-voltage DC power supply of the test object is protected from short circuit, for example, when the rechargeable battery is used as the test object, the test object has a high probability of overcurrent output to the product due to the connection and setting. As a result, the test object will form short circuit. In order to design a protection circuit for high voltage DC power supply, detecting this overcurrent and limiting the current is the key.

A protection circuit is usually inserted into the high voltage DC power supply so that the product under test can withstand the high voltage bidirectional constant current circuit. High voltage DC power supply 50kV high voltage use of protection circuit, that is, two-way constant current circuit. If it is not protected in time, it can work normally until the high voltage DC power supply reaches the breakdown voltage, but with the continuous increase of the applied voltage, when the breakdown voltage is applied to about twice the voltage, the high voltage DC power supply internal protection circuit is damaged, so that the constant current control cannot continue.