southern taiwan university of science and technology

Reporter: Nguyen Phan ThanhID Student: DA220202

Southern Taiwan University of Science and Technology

FEEEEnsuring Enhanced Education

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Contents

• Introduction

• Mathematical model of PMSM

• Sensor Control Architechture

• High performance motor control application


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PM synchronous motors are widely used in industrial servo-applications due to its high-performance characteristics.

CompactHigh efficiency (no excitation current)Smooth torqueLow acoustic noiseFast dynamic response (both torque and speed)

Introduction

A synchronous motor differs from an asynchronous motor in the relationship between the mechanical speed and the electrical speed.


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Introduction


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2-axis reference frame:The stator and rotor equations are referred to a common frame of reference •Stator (stationary) reference frame : non-rotating • Synchronous reference frame: d, q axis rotates with the synchronous angular velocity

Introduction


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• The stator reference axis for the a-phase direction: maximum mmf when a positive a-phase current is supplied at its maximum level.

• The rotor reference frame: -D-axis: permanent magnet flux -Q-axis: 90 degree ahead of d-axis

The d-q model has been used to analyze reluctance synchronous machines.

Introduction


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• As the motor spins, there is an angle between rotor magnetic field and stator magnetic field

• If these two magnetic fields are not ninety degrees from each other, there will be an offset angle between Back EMF and Current:

=>the torque production at a given input power will not be the maximum

Introduction


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• With this animation we can see how the commutation angle is always ninety degrees ahead of the rotor.

• On the left we see how the motor spins with Field Oriented Control.

• On the voltage diagrams we show how the output voltages have a sinusoidal shape.

• On the lower right we see the rotor angle changing from minus pi (minus one eighty degrees) to plus pi (plus one eighty degrees).

Introduction


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Introduction


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Introduction


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Introduction


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Introduction


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Introduction


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The mathematical model of PMSM is constructed based on the rotating d-q frame fixed to the rotor, described by the following equations:

Where: •v d, vq are the d and q axis voltages•id, iq are the d and q axis currents•Rs is the phase winding resistance •Ld, Lq are the d and q axis inductance• is the rotating speed of magnet flux• is the permanent magnet flux linkage.

Mathematical model of PMSM


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Mathematical model of PMSM


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Command Pulse Deviation Counter Kp Kv Ki M

E

Speed detection

Current Feedback

Speed Feedback

Pulse Feedback

_

+ + +

_ _

Position Gain

Speed Gain CurrentGain

Motor

Encoder

Closed_loop Control

Operation of PMSM


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SVPWM

DCPower

PMSM

PI

Inverter

A/D

convert

PWM1

0* di

qi

di

ui

vi

Park Clark

Park-1

modifyClark-1

PWM6

—

—++

—PWM2PWM3PWM4PWM5

PI

1refv

3refv2refv

qv

dv

v

v

i

i

ai

bi

sin /cos of Flux angle QEP

*qi

r

*r

r1-Z-1 Encoder

ABZ

+

ci

a,b,c

,d,q

,

,

d,q ,

a,b,c

Current controller

SpeedController

Current loopSpeed loop

e

PI, Fuzzy, Neural network are used to

the speed loop of PMSM drive

Vector control is used to the current loop of PMSM drive to let it reach the linearity and decouple characteristics.

Sensor Control Architechture


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SVPWM

DCPower

PMSM

PI

Inverter

A/D

convert

PWM1

0* di

qi

di

ui

vi

Park Clark

Park-1

modifyClark-1

PWM6

—

—++

—PWM2PWM3PWM4PWM5

PI

1refv

3refv2refv

qv

dv

v

v

i

i

ai

bi


*qi

r

*r

r1-Z-1 Encoder

ABZ

+

ci

a,b,c

,d,q

,

,

d,q ,

a,b,c

Current controller

SpeedController


e

The entire process is illustrated in this block diagram, including coordinate transformations, PI iteration, transforming back and generating PWM



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SVPWM

DCPower

PMSM

PI

Inverter

A/D

convert

PWM1

0* di

qi

di

ui

vi

Park Clark

Park-1

modifyClark-1

PWM6

—

—++

—PWM2PWM3PWM4PWM5

PI

1refv

3refv2refv

qv

dv

v

v

i

i

ai

bi


*qi

r

*r

r1-Z-1 Encoder

ABZ

+

ci

a,b,c

,d,q

,

,

d,q ,

a,b,c

Current controller

SpeedController


e

•The Id reference controls rotor magnetizing flux•The Iq reference controls the torque output of the motor•Id and Iq are only time-invariant under steady-state load conditions



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SVPWM

DCPower

PMSM

PI

Inverter

A/D

convert

PWM1

0* di

qi

di

ui

vi

Park Clark

Park-1

modifyClark-1

PWM6

—

—++

—PWM2PWM3PWM4PWM5

PI

1refv

3refv2refv

qv

dv

v

v

i

i

ai

bi


*qi

r

*r

r1-Z-1 Encoder

ABZ

+

ci

a,b,c

,d,q

,

,

d,q ,

a,b,c

Current controller

SpeedController


e

•The outputs of the PI controllers provide Vd and Vq, which is a voltage vector that is sent to the motor. •A new coordinate transformation angle is calculated based on the motor speed, rotor electrical time constant, Id and Iq.



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SVPWM

DCPower

PMSM

PI

Inverter

A/D

convert

PWM1

0* di

qi

di

ui

vi

Park Clark

Park-1

modifyClark-1

PWM6

—

—++

—PWM2PWM3PWM4PWM5

PI

1refv

3refv2refv

qv

dv

v

v

i

i

ai

bi


*qi

r

*r

r1-Z-1 Encoder

ABZ

+

ci

a,b,c

,d,q

,

,

d,q ,

a,b,c

Current controller

SpeedController


e

•The Vd and Vq output values from the PI controllers are rotated back to the stationary reference frame, using the new angle.•This calculation provides quadrature voltage values vα and vβ.



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SVPWM

DCPower

PMSM

PI

Inverter

A/D

convert

PWM1

0* di

qi

di

ui

vi

Park Clark

Park-1

modifyClark-1

PWM6

—

—++

—PWM2PWM3PWM4PWM5

PI

1refv

3refv2refv

qv

dv

v

v

i

i

ai

bi


*qi

r

*r

r1-Z-1 Encoder

ABZ

+

ci

a,b,c

,d,q

,

,

d,q ,

a,b,c

Current controller

SpeedController


e

•The vα and vβ values are transformed back to 3-phase values va, vb, vc.•The 3-phase voltage values are used to calculate new PWM duty-cycle values that generate the desired voltage vector.



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SVPWM

DCPower

PMSM

PI

Inverter

A/D

convert

PWM1

0* di

qi

di

ui

vi

Park Clark

Park-1

modifyClark-1

PWM6

—

—++

—PWM2PWM3PWM4PWM5

PI

1refv

3refv2refv

qv

dv

v

v

i

i

ai

bi


*qi

r

*r

r1-Z-1 Encoder

ABZ

+

ci

a,b,c

,d,q

,

,

d,q ,

a,b,c

Current controller

SpeedController


e

The transformation angle, theta, and motor speed are coming from an optical encoder mounted on the shaft of the motor.



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Motor Driver Controller


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Industrial drives, e.g., pumps, fans, blowers, mills, hoists, handling systems Elevators and escalators, people movers, light railways and streetcars

(trams), electric road vehicles, aircraft flight control surface actuation

High performance motor control application


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