Overcurrent protection method of direct current converter

Abstract

The invention relates to the field of power electronization power system and discloses an overcurrent protection method of a direct current converter. The method comprises the steps of setting a direct current converter output current instantaneous protection value according to a design margin in an element selection process, making overload and fault current limiting index requirements of the direct current converter by a system to be clear, determining a voltage-current characteristic of direct current converter steady-state output, fitting a mathematical relationship between power and a maintenance time, and forming protection scheme according to the normal, overload, fault current limiting and instantaneous overcurrent working conditions. According to the overcurrent protection method of the direct current converter, the requirements of system selective protection is fully considered, with the coordination with other protection elements of the system or a device, the complete overcurrent protection function of the direct current converter in the normal, overload, fault current limiting and instantaneous overcurrent working conditions is realized, and the power supply continuity of an power electronization power distribution network is improved.

Description

technical field [0001] The invention relates to the field of power electronic power systems, in particular to an overcurrent protection method for a DC converter. Background technique [0002] In the DC distribution network, as the main power supply equipment, the DC converter needs to have a complete over-current protection function while ensuring the safety of the equipment itself under extreme conditions such as short circuit and overload, so as to coordinate with circuit breakers and fuses. and other protection elements or devices in the system to achieve selective protection. [0003] However, since the main circuit inside the DC converter is dominated by power semiconductor devices, and the physical characteristics of the power semiconductor devices themselves determine that their overload capacity outside the safe operating area is relatively poor, and it is easy to cause overcurrent, overvoltage and other extreme working conditions. If the power semiconductor device...

AI Technical Summary

Problems solved by technology

[0003] However, since the main circuit inside the DC converter is dominated by power semiconductor devices, and the physical characteristics of the power semiconductor devices themselves determine that their overload capacity outside the safe operating area is relatively poor, and it is easy to cause overcurrent, overvoltage and other extreme working conditions. If the power semiconductor device is damaged or the drive protection circuit is activated, the DC converter will stop immediately

However, the overcurrent protection method of traditional power electronic devices only considers the safety of the internal components of the device, and it is difficult to achieve coordination with other protection components or devices in the system, which may cause large-scale power loss and affect the continuity of the power supply of the network.

Images