Rectifier Transformer 1

[Borti]

Hi everybody.

Could somebody tell me if typical ANSI trough-fault protection curve can be applied on a 3-winding rectifier transformer?

 

[electricuwe]

I'm afraid you can not use such a curve. Each secondary of a three winding rectfier transformer is just rated for half of the total power.

Using such transformers I have usually applied the following kind of protection:

- current transformers on each secondary, connected to the rectifier control unit which was able to trip the primary circuit breaker via a undervoltage release coil in case of a failure
- additionaly the primary ciruit breaker was set up to trip on very large fault currents

 

[busbar]

For ANSI regions, one salient reference may be IEEE Std C57.18.10-1998 ...Practices and Requirements for Semiconductor Power Rectifier Transformers with TOC at standards.ieee.org/reading/ieee/std_public/description/dtransformers/C57.18.10-1998_desc.html