UM0324 datasheet(65/105 Pages) STMICROELECTRONICS

65 / 105 page

UM0324

Library functions

65/105

As a result of data processing, the following information can be obtained:

●

highest frequency of constant torque region, i.e. the maximum allowable frequency

before entering field weakening; content of cell B13 should be inserted (as parameter

RATED_FREQ

) in MC_ACMotor_Prm.h (see Section 2.2.5);.

●

reference values of ids, in q1.15 format, according to increasing stator frequency;

column P should be copied (as hFlux_Reference) in MC_ACMotor_Prm.h.

●

saturation values of current component iqs, in q1.15 format, according to increasing

stator frequency; column Q should be copied (as hTorque_Reference) in

MC_ACMotor_Prm.h

4.5

Reference frame transformations: MC_Clarke_Park.h

module

4.5.1

Overview

This module, intended for AC machines (induction, synchronous and PMSM), is designed to

perform transformations of electric quantities between frames of reference that rotate at

different speeds.

Based on the arbitrary reference frame theory, the module provides three functions, named

after two pioneers of electric machine analysis, E. Clarke and R.H. Park.

These functions implement three variable changes that are required to carry out field-

oriented control (FOC):

●

Clarke transforms stator currents to a stationary orthogonal reference frame (named qd

frame, see Figure 40);

●

then, from that arrangement, Park transforms currents to a frame that rotates at an

arbitrary speed (which, in IFOC drive, is synchronous with the rotor flux);

●

Reverse Park transformation brings back stator voltages from a rotating qd frame to a

stationary one.

UM0324 Datasheet(PDF) 65 Page - STMicroelectronics