Saturation model in ESDC2A can be incorrect

[jinningwang]

@cuihantao
Hi Hantao,

I think the ESDC2A model may be incorrect.

I think the self.VFE.e_str should be

e_str='(INT_y*KE + Se*INT_y) - VFE'

The ESDC2A, the code said:

        self.Se = Algeb(tex_name=r"V_{out}*S_e(|V_{out}|)", info='saturation output',
                        v_str='Se0',
                        e_str='SL_z0 * (INT_y - SAT_A) ** 2 * SAT_B - Se',
                        )

        self.VFE = Algeb(info='Combined saturation feedback',
                         tex_name='V_{FE}',
                         unit='p.u.',
                         v_str='vfe0',
                         e_str='(INT_y*KE + Se) - VFE'
                         )

However, the control diagram shows:

[cuihantao]

I think my implementation is correct. The self.Se variable is actually EFD * Se(EFD) in the block. It was noted in the tex_name of self.Se. I also put a note before self.Se0.

See page 16 in Neplan's exciter manual. https://www.neplan.ch/wp-content/uploads/2015/08/Nep_EXCITERS1.pdf: SE = B * (U - A)** 2 / U. Our Se has already been multiplied by U, which is vf.

[jinningwang]

Thanks for your reply!

The control diagram from PowerWorld has two type equations (like the attached picture), which confused me sometimes. I'll follow your implementation.

AC8B

[cuihantao]

The drawing in AC8B is probably an error. Se alone is just a ratio of the saturated Vf (aka Efd) over the unsaturated Vf. It should be Efd*Se that gets added to Ke. Regards, Hantao Cui

…

On Sep 26, 2021, 11:05 PM -0500, Jinning Wang ***@***.***>, wrote: Thanks for your reply! The control diagram from PowerWorld has two type equations (like the attached picture), which confused me sometimes. I'll follow your implementation. AC8B — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub, or unsubscribe.

[jinningwang]

Thanks!

Regards,
Jinning