Reduction of Torque Ripple in 3 Phase SRM Drive using Hybrid (Intelligent) Controller · 2018. 11....

Reduction of Torque Ripple in 3 Phase SRM

Drive using Hybrid (Intelligent) Controller

1 Vanakuri. Divya, Student, Department of EEE, K L University, Guntur, India

2Yalamanchi Amrutha naga sree, Student, Department of EEE, K L University, Guntur, India

3 Sankuri Rajasekhar, Assistant Professor, Department of EEE, K L University, Guntur, India

Abstract- Now a days, Switched Reluctance Motors (SRMs)

attract additional and additional attention. The Switched

Reluctance Motor is easy to construct. It not solely options

a salient pole mechanical device with focused coils, that

permits earlier winding and shorter finish returns than

different forms of motors, but additionally options a salient

pole rotor, that has no conductors or magnets and is

therefore the best of all electrical machine rotors which

merely makes the SRM cheap and reliable, and alongside

its high speed capability and high torsion force to inertia

magnitude relation, makes it a superior selection in several

applications. The target of this paper is to accomplish

craved speed execution of 6/4 Switched Reluctance Motor

(SRM) with decreased drive swells. to acknowledge

enhanced speed execution, PI+FUZZY controller was

presented. Twofold shut circle framework is utilized for the

higher speed execution qualities. to weaken the torsion

compel swell, 3 entirely unexpected administration ways

(PI, fuzzy and PI in addition to fuzzy) which are

anticipated. Reproduction result comes about reassert the

adequacy inside the parts of higher speed execution and

torsion compel swell decrease.

Keywords–Switched reluctance motor drives, device topology,

fuzzy controller.

I. INTRODUCTION

Exchanged Reluctance Motors have benefits

like fast operation, high level of autonomy between

stages, short end-turn, and low latency. Exchanged

Reluctance Drive (SRD) could be a stage less speed

control framework that comprises of SRM, convertor

and controller. Be that as it may, administration system,

converter's topology and streamlining style of SRM have

pivotal impact on execution of SRD. In this manner,

dynamic reproduction of the full SRD has turned out to

be essential. in order to get prime quality administration

in either compel or speed administration applications, it's

fundamental to have relate revise model of the engine

that depicts the drive attributes [1, 2].

The SRM's drive execution is intensely fixated

on its style and absolutely on its administration that

grants for torsion swell diminishment, or for rising the

speed administration. Subsequently, the engine's

numerical model and its precision is essential [3]. SRM

direct and nonlinear model with the voltage and physical

wonder current administration said in [4]. A rearranged

straight model for control framework administration of

SRM with PI controller is offered in [5]. Jin Woo Lee et

al. [6-7], anticipated an engine with scored teeth

however the new engine shapes can affect the basic

torsion worth. In [8] very surprising power

administration methodologies and a drive controller

execution for compel swell decrease are clarified.

Torque swell decrease in exchanged hesitance

engines (SRM) has turned into a genuine investigation

topic for this machine nowadays. In servo administration

applications or once wash administration is required at

low speeds, decrease of compel swell turns into the most

issue in a suitable administration procedure. Amid this

International Journal of Applied Engineering Research ISSN 0973-4562 Volume 12, Number 1 (2017) © Research India Publications. http://www.ripublication.com

447

case, notwithstanding utilizing a fluffy PI-like

administration in light of the fact that the one depicted in

[9], the outcomes aren't palatable thus of the controller's

yield, that is utilized as a kind of perspective flag for the

present administration inside the power convertor,

causes maintained compel motions in relentless state. in

addition, constrain swell modifies with the speed of the

SR engine and with the extent of the heap connected to

that. the essential approach for torque-swell decrease in

SRMs exploitation a disconnected learning procedure is

arranged in [10]. A leap forward disconnected approach

is presented in [11] and [12], conjointly utilize delicate

processing methods to be advised the least complex

perform to reduce the swell. As of late, a considerable

measure of refined learning administration calculations

were arranged [13]-[15] that expanded on-line

approaches adjusting the controller to changes inside the

engine's qualities.

II.PRINCIPLE OPERATION OF SRM

Exchanged Reluctance Motor has wound field

loops of a dc engine for its mechanical gadget windings

and has no curls or magnets on its rotor. Each the

mechanical gadget and rotor have remarkable posts, thus

the machine is seen as a doubly notable machine.

Exchanged Reluctance Motors are made from overlaid

mechanical gadget and rotor centers with Ns=2mq posts

on the mechanical gadget and 𝑁𝑟 shafts on the rotor. The

amount of parts is m and each stage is made from

centered curls put around 2q mechanical gadget shafts.

Most supported arrangement among a few decisions

square measure 6/4 three stage and 8/6 four stage

Switched Reluctance Motors as appeared inside the

figure one. These 2 setups compare to q = 1(one attempt

of mechanical gadget shafts and loops per stage)

however q could likewise be sufficient to2 or 3

moreover. With only one section exchanged on; the rotor

are very still in an exceedingly position that gives least

hesitance to the flux made by that part amid this

position, there'll not be any created compel on the rotor.

Presently if that part is changed over and another part

exchanged on; the rotor encounters a constrain tending to

move it to a base hesitance position love the new part.

Whichever course of development offers the littlest sum

separation to be hostage by the rotor to accomplish the

new least hesitance position is that the bearing of rotor

movement. on an individual premise energized attraction

transfers are dissected abuse the standards of mechanical

gadget vitality transformation Expressions for attraction

torsion are created. These outcomes are frequently

reached out to the exchanged hesitance engine, and

furthermore the expression for the torsion is acquired

𝑇𝑒 = 𝑑𝐿(𝜃,𝑖)

𝑑𝜃 𝑖2

2

(1)

Figure 1: Basic three phase 6/4 SRM

III.CONVERTER TOPOLOGY

The SR drive has additional advantages

contrasted and the standard flexible speed air

conditioning or brushless dc drives (counting perpetual

magnet engine drives). To begin with, shoot through

issues are impractical. This is frequently valid for all SR

convertor circuits therefore of theirs constantly an engine

twisting offbeat with each fundamental power switch

gadget. Second, there's a greater level of freedom

between the stages than is achievable in run of the mill

air conditioning or brushless dc drives. Blame in one

segment (regardless of whether inside the engine or

inside the converter) regularly influences exclusively

that stage; the inverse stages will even now work

severally. Among those converters, the uneven scaffold


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convertor is that the most all around loved and best-

performed one, inside which each area branch comprises

of 2 particular switch components and 2 freewheeling

diodes as appeared in fig 2.

,

VDC Phase A Phase B Phase C

S1

S2

S3

S4

S5

S6D1

D2

D3

D4 D6

D5

Figure 2: Asymmetrical bridge device for three phase 6/4 pole SRM

When switches S1 and S2 are turned ON, the section A

is energized ,as shown in figure 3.

VDCPhase A Phase B Phase C

S1

S2

S3

S4

S5

S6D1

D2

D3

D4 D6

D5

Figure 3: Current path when phase A is energized

At the point when switches S1 and S2 are killed, the

diodes D1 and D2 are forward one-sided. Amid this case

area A is de-energized.as appeared in figure 4.

VDCPhase A Phase B Phase C

S1

S2

S3

S4

S5

S6D1

D2

D3

D4 D6

D5

Figure 4: Current path when phase A is de-energized

IV.SPEED CONTROL OF SRM

A. with PI controller

Here initially PI controller is received to get the

reference current for the comparing speed blunder. By

factor 𝐾𝑝 , 𝐾𝑖 pick up qualities for the PI controller,

keen outcomes territory unit acquired as far as reaction.

Since, the attractive conduct of SRM is extremely

nonlinear, PI controller can't be connected with the

frameworks that have a speedy change of parameters,

accordingly of it may require the alteration of PI

constants inside the time.

Fig 5: Closed loop speed control of SRM

Fig.6.Closed loop speed control of SRM with Torque ripple reduction.

B. with PI+FUZZY controller

It is accepted that the fuzzy logic Controller is

extremely sensitive to load disturbances or fast changes,

once the parameters are well chosen, the response of the

system has excellent time domain characteristics.

However, vital unfaltering state mistake contrasted and

the standard corresponding necessary controller. Fuzzy

controller has the disadvantage of computing time is

much more long that for PI. Hence it'll be higher to


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decide on the mixture of PI and FUZZY. It means the

system will be well controlled by PI that is supervised by

a fuzzy system. Rules for the fuzzy logic controller are

tabulated as follows.

Fig 7: Membership functions for FLC

Table 1: Fuzzy Rules for FLC

Fuzzy rules can be explained as follows

Rule 1 if ∆ω = S and ∆ω′= M/S then 𝐼𝑟𝑒𝑓 =S

Rule 2 if ∆ω = M/H and ∆ω′= M then 𝐼𝑟𝑒𝑓 =M/S

Rule 3 if ∆ω = H and ∆ω′=M/H then 𝐼𝑟𝑒𝑓 =M/H

As indicated by the component of control speed

framework specified and measure of speed inspecting,

speed blunder ∆ω ,change in mistake ∆ω′ and Current ref

are started to have scope of - 1000-1000rpm, - 200-200

and 0-10A,. The spaces of the information factors range

unit changed to - 5 to five and zone unit partitioned into

5 fluffy districts. The area of the yield variable is zero to

ten and is also partitioned into five fluffy districts, that is

[0,2.5,5,7.5,10].The corresponding linguistic variables of

the input fuzzy regions area unit Small(S), Medium to

Small(M/S), Medium(M), Medium to High(M/H),

High(H). Every region is assigned a fuzzy membership

operate. During this work, the fuzzy sets area unit

chosen to be triangular shapes and therefore the center of

space (COA) methodology of de-fuzzification is

employed.

C. Torque ripple reduction

There are several factors to have an effect on

the force ripple, like rotor and/or stator coil form, air

length, commutation strategy, management strategy then

on, however the foremost necessary issue is part current.

This paper presents varied methods to cut back force

ripple for a Switched Reluctance Motor. 1st strategy is to

develop the inner force loop to get current reference so

as to reduce the force ripple. The magnetism force that is

obtained from the motor is taken to induce the present

reference from the relation T ∝ 𝐼2 Fig.6 shows the

diagram model for torsion ripple reduction. second is

modification in rotor pole arc at the planning stage. By

dynamical the rotor pole arc of the SRM conjointly

torsion ripple has been reduced to bound limit. On the

off chance that the rotor shaft circular segment is greater

than that of the stator loop post curve, there's no

unmistakable benefit as far as torsion generation on the

SRM if a perfect current kill is imagined [8] .

Perfect current kill is unrealistic with SRMs, as

they need imperative inductance. Indeed, the most

essential inductance is experienced at kill, wherever it's

apparently at the totally adjusted position of the

mechanical gadget and rotor shafts wherever the

inductance is at its most. Along these lines, it gets to be

distinctly important to flaunt the streams even before

they achieve the absolutely adjusted position. Thus, to

use the torque-delivering positive inductance slant area

absolutely, it is essential that the present be kept up

inside the district. On the off chance that the present

proceeds on the far side the positive slant district, then a

negative torsion is made in SRMs with equal mechanical

device and rotor pole arcs, as a result of there's no zero

slope inductance region, because of the negative torsion

generation, the typical per mechanical device section is

reduced. Accordingly, it gets to be distinctly important to

flaunt the streams even before they achieve the

completely adjusted position. And it's higher to avoid


450

equal pole arcs. to own a higher general read of the

torsion ripple, outline the torsion ripple coefficient:

𝑇𝑅𝐼𝑃𝑃𝐿𝐸 =𝑇(max) − 𝑇(min)

𝑇(𝑎𝑣𝑔)

%

Where T(max), T(min) are the maximal esteem and

insignificant estimation of aggregate torque, T(avg) is

the normal estimation of aggregate torque.

V. SIMULATION RESULTS

The SRM drive is simulated with PI, fuzzy

controller alone and with PI plus FUZZY controller

exploitation MATLAB/SIMULINK. and therefore the

results obtained square measure shown in fig. 7. From

the figure we will clearly observe the unfaltering state

and transient reaction of the model. By utilizing PI plus

FUZZY controller. But it has significant steady state

error which can be reduced by PI controller. Hence by

using a combination of these controllers, the response of

the model increases to certain extent.

Case I: SRM with PI Controller.

Fig.7.Matlab/Simulation model of SRM drive with PI controller

Fig.8.Current waveform of SRM with PI Controller.

Fig.9.Torque waveform of SRM with PI Controller.

Fig.10.Speed response of SRM with PI Controller.

Case II: SRM with fuzzy Controller

Fig.11.Matlab/simulation model of SRM drive with fuzzy controller.

Fig.12.Current waveform of SRM with fuzzy Controller.


451

Fig.13.Torque waveform of SRM with Fuzzy Controller.

Fig.14.Speed response of SRM with fuzzy Controller.

Case III: SRM with PI+fuzzy Controller

Fig.15.Matlab/Simulation model of SRM drive with PI+fuzzy

controller

Fig.16.Current waveform of SRM with PI+fuzzy Controller.

Fig.17.Torque waveform of SRM with PI+Fuzzy Controller.

Fig.18.Speed response of SRM with PI+fuzzy Controller.

VI. CONCLUSION

This paper presents the shut circle control of three stage

exchanged hesitance engine (SRM) drive. Another

unbalanced scaffolds converter topology is implemented

for the drive system. Closed-loop system management

exploitation PI controller with totally different 𝐾𝑃 and 𝐾𝐼

values are bestowed. during this paper, an effective

element demonstrate for reproducing customizable speed

execution of a SRM drive has been delineate very well

SRM modeling, speed performance analysis with PI,

fuzzy and PI plus FUZZY controller has been presented.

With the PI plus FUZZY controller the steady state and

transient response is improved. Along with this, Torque

ripple reduction of SRM using three different methods is

discussed. Torque ripple is calculated by taking inner

torque loop, with which ripple has been reduced to

considerable amount. By applying the remaining two

methods, we can get reduced torque ripple for different

applications. This layout is an immaculate device to

approve the execution of the different administration


452

calculations all through consistent state related transient

condition of a SRM drive for any very applications.

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Reduction of Torque Ripple in 3 Phase SRM Drive using Hybrid (Intelligent) Controller · 2018. 11....

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