Transformer differential protection improves and perfects the realization of traditional protection
techniques with computer’s technical advantages. It is necessary to study the fault of transformer to explore
new protection principle, and improve the transformer protection performance. But there are many
drawbacks on test, for example: testing environment, testing conditions, safety and so on. To overcome
these shortcomings, we used the system based on simulink technology,and complete a compreh-ensive
simulation test of real units and operating environment. It can significantly reduce the development and
testing costs, and it can shorten the development cycle too.