A short-circuit protection action current adjusting method for a multi-pole electromagnetic release, wherein each electromagnetic system of the electromagnetic release comprises an auxiliary static iron core, a second static iron core, a coil, a reset spring and a dynamic iron core;
- at an initial position, a second gap L2 is formed between the dynamic iron coreand the second static iron core, and the thickness of the second gap L2 changes in the same direction along with the size variation of a release threshold;
- the elastic force of the reset spring changes oppositely along with the size variation of the release threshold;
- when a release current value is adjusted from large to small, the self-induction magnetic energy of the coil reduces in a quadratic relationship mode along with flowing currents and meanwhile the electromagnetic attraction between the dynamic iron core and the second static iron core is increased in a quadratic relationship mode, which is in inverse proportion to reduction of the thickness of the second gap L2;
- adjustment of the release current value and electromagnetic attraction required by actions of the dynamic iron core are in a linear fixed corresponding relationship due to automatically achieved balance between two quadratic functions.