Based on MPTA+ field weakening control (direct calculation method) + current decoupler PMSM system simulink implementation

Overall Control Block Diagram

：
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The flow of the control algorithm:

insert image description here First of all, let's talk about the concept and formula of current limit circle and voltage limit circle:

1. Voltage limit circle

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Bring in to get:

2. Current limit circle

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When the motor is in a steady state, draw the voltage constraint equation and current constraint equation on the id and iq planes, as shown in the figure:
when considering the influence of the stator resistance, the ability to output torque decreases at a given speed ;Under a given torque, the maximum speed that can be achieved is also reduced; therefore, when the speed is high, the influence of resistance is ignored (the above figure does not consider the influence of stator resistance).

2. Three areas of field weakening control

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Area 1: The rotational speed of PMSM in this area is lower than the turning speed. Since the
field weakening has not been performed in this area, the output is constant torque, so area 1 is also a constant torque operation area. In order to make full use of the output capacity of the motor, the MTPA control method is often used in this interval.
Area 2: This area is the general field-weakening area. The PMSM’s speed is greater than the turning speed. Why do we
no longer use MTPA at this time and use a specific field-weakening strategy? As shown in the figure below,
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when the idiq characteristic of the motor is in the MTPA curve, suppose Speed up to the voltage limit
circle where BC is located. At this time, the electromagnetic torque output capabilities of point B and point C are obviously different, and the electromagnetic torque output capability of point C is obviously greater than that of point B. If the d-axis current is given according to the MTPA curve, the output capability of the motor will decrease, so the idiq characteristic at point C needs to be used.
The stator current component is obtained according to the following formula:
insert image description here the running track of id can be obtained as:

The relationship shown in the figure above is obtained through the intersection of the voltage limit circle and the current limit circle. The
stator current trajectory of the motor runs along the intersection of the current limit circle and the voltage limit circle, and the amplitude is always kept at the Ilim
area 3: area 3 also becomes the deep field weakening area and field weakening area 2, not all motors exist in
area 3, only when lim /  fd LI  will exist, the difference in this relationship can be reflected in the voltage limit circle and current limit circle in the coordinate system.
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So it can be seen that the curves of magnetic field weakening are also different.
When the motor is running in this area, the stator current components id and iq can be obtained according to the following formula:

3. Slimulink simulation control

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3.1 Given speed

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3.2 Speed loop PI

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3.3 Control algorithm (MPTA+field weakening)

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The internal structure of which is

the internal structure of MPTA:

the internal flux-weaking control is:

3.4 Current Loop PI

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3.5 Decoupling the current controller code

function [ud_out,uq_out]   = fcn(ud,uq,id,iq,we,pisa,Ld,Lq)



ud_out=ud-iq*we*Lq;
uq_out=uq+id*we*Ld+we*pisa;


end

3.5 Inverter parameters

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3.6 Three-phase voltage and current measurement module

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3.7 Motor parameters

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3.8 Speed waveform

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3.9 Torque waveform

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