UM0324 datasheet(23/105 Pages) STMICROELECTRONICS

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UM0324

Getting started with the library

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period has been increased by a factor of 10 at least), the number of overflows is not

counted anymore. This usually indicates that information is lost (tacho time-out) or that

the speed is decreasing very sharply. The corresponding duration depends on the

tacho timer prescaler, which is variable; the higher the prescaler (at low speed), the

longer the time-out period.

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#define SPEED_FIFO_SIZE

This is the length of the sofware FIFO in which the latest speed measurements are

stored. This stack is necessary to compute rolling averages on several consecutive

data.

2.2.5

AC induction motor parameters: MC_ACmotor_param.h

The MC_ACmotor_param.h header file holds motor parameters which are essential to

properly operate the IFOC vector drive.

The following parameters must be defined in all cases:

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#define ROTOR_TIME_CONSTANT

Define here (in µs), the rotor open circuit time constant of the motor

τ r :

where Lm is the magnetizing inductance, Llr is the rotor leakage inductance, Lr is the

rotor inductance, rr is the rotor resistance.

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#define POLEPAIR_NUMBER

Define here the stator winding pole pair number;

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#define RATED_FREQ

Define here (in 0.1Hz) the right-hand boundary of the constant torque region (see

Figure 8): in that region we have rated current, rated flux, rated torque, rated power;

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hNominal_Flux

Define here the required magnetizing current im (positive, peak value), expressed in

q1.15 format (see Section A.3 on page 99).

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