UM-YROTATE-IT-RX62T datasheet(23/54 Pages) RENESAS

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RX62T

YROTATE-IT-RX62T Motor Control Kit

UM-YROTATE-IT-RX62T Rev.1.00

Page 23 of 51

Jan 15, 2014

12. Flux Feedback Gain

The block scheme of the exact BEMF integration method for flux position estimation is the following:

The inputs of the system are the imposed voltage vector V and the measured current vector I.

The motor phase resistance Rs, the synchronous inductance Ls and the permanent magnet flux amplitude

m are

known as parameters and motor specific.

The integral operation is corrected with a signal obtained modulating accordingly with the estimated phase the error

between the estimated flux amplitude and the amplitude of the permanent magnets flux. The gain of this correction

is indicated with G and it is this feedback which avoids the integral divergence due to the errors, offsets and so on.

The higher G is, the higher is the correspondence between the estimated amplitude and the theoretical one, but the

larger can be the induced phase error. The choice of G is a compromise, in order to guarantee that the integral

remains close to its theoretical value, but free enough to estimate the correct system phase.

∫∫∫∫

∠



λλλλ

ϑϑϑϑ

λλλλ

UM-YROTATE-IT-RX62T 数据表(PDF) 23 Page - Renesas Technology Corp