基于二阶广义积分器的锁相环设计

ANewSingle-Phase

PLLStructure

Based

onSecondOrder

Generalized

Integrator

MihaiCiobotaru,

RemusTeodorescuandFredeBlaabjerg

AalborgUniversity

InstituteofEnergyTechnology

Pontoppidanstraede101,

9220Aalborg

DENMARK

mpc~a,iet.

aau.dk,

ret-_iet.

aau.dk,1ial

aau.dk

Abstract

-Phase,amplitude

andfrequency

oftheutilityvoltagemonitoringisused

toensurethattheperformances

of

agrid-

arecriticalinformationfortheoperation

ofthegrid-connected

connectedsystemcomply

withthestandardrequirementsfor

invertersystems.Insuchapplications,

anaccurateandfastoperationundercommon

utilitydistortions

aslineharmonics

detectionofthephaseangle,amplitude

andfrequency

ofthe

/notches,voltagesags/swells/loss,frequency

variationsand

utility

voltageisessential

toassurethe

correctgeneration

ofthe

referencesignalsand

tocopewiththe

newupcoming

standards.PheJum

.

P

Thispaperpresentsanewphase-locked-loop(PLL)

methodforThegeneral

structureofasingle-phase

PLLincluding

the

single-phasesystems.Thenovelty

consistsingenerating

thegridvoltagemonitoringisshowninFig.1.Usually,themain

orthogonalvoltagesystemusing

astructurebasedonseconddifference

amongdiverssingle-phase

PLLmethodsisthe

ordergeneralizedintegrator(SOGI).

Theproposed

structureorthogonalvoltage

systemgeneration

structure.

hasthefollowingadvantages:

-ithas

asimpleimplementation;

-

thegeneratedorthogonalsystemisfilteredwithoutdelayby

the

v

V,

o,,

samestructuredue

toits

resonanceatthefundamental

frequency,

-theproposed

structureis

notaffectedby

the

vif

v

c°

frequencychanges.Thesolutionsforthediscrete

implementation

ofthe

newproposed

structure

arealsov

presented.Experimental

resultsvalidatetheeffectivenessofthe

qvVd

proposed

method.

1.INTRODUCTION

TV=

..~~~~~~Fig.

1.Generalstructureofasingle-phasePLL

Phase,amplitude

andfrequencyoftheutility

voltage

are

criticalinformationfortheoperation

ofthegrid-connected

Aneasywayofgeneratingtheorthogonalvoltagesystem

inverter

systems.Insuchapplications,

anaccurateandfast

inasingle-phasestructureisusingatransportdelayblock,

detectionofthephaseangle,amplitudeandfrequency

ofthe

whichisresponsibleforintroducingaphaseshiftof90

utilityvoltageisessential

toassurethe

correctgeneration

of

degreeswithrespecttothefundamentalfrequencyofthe

thereferencesignalsand

tocopewiththe

newupcoming

inputsignal(gridvoltage).Arelatedmethod,

butmore

standards.

complexofcreatingaquadraturesignalisusingtheHilbert

Mostrecently,therehasbeen

anincreasing

interestin

transformation[3].Anotherdifferentmethod

ofgenerating

Phase-Locked-Loop(PLL)topologiesforgrid-connected

theorthogonalvoltagesystemisusinganinversePark

systems.The

PLLis

agridvoltagephasedetection

structure.Transformation

aspresentedin[1],[3],[4]and[5].Allthis

Inorder

todetectthisphase

anorthogonalvoltage

systemis

methodshassomeshortcomingsasfollows:frequency

required.

Insingle-phase

systemsthereislessinformation

dependency,highcomplexity,nonlinearity,

poorornone

thaninthree-phase

systemsregarding

thegridcondition,

sofiltering.Thus,furtherattentionshouldbepaidonsingle-

moreadvancedmethodsshouldbeconsideredinorder

tophasePLLsystems.

createanorthogonalvoltage

system[1]-[6].

Thispaperpresentsanewmethodofsingle-phasePLL

Themaintaskof

aPLLstructureis

toprovide

aunitary

structurebasedonsecondorderGeneralizedIntegrator(GI).

powerfactoroperation,whichinvolvessynchronizationofTheproposedmethodisagoodalternativeforcreatingan

theinverteroutputcurrentwiththegridvoltage,andtogiveaorthogonalsysteminsingle-phasesystemscomparedto

cleansinusoidalcurrentreference.AlsousingaPLLknownmethod[1]-[5].Thismethodisfurtherpresentedand

structurethegridvoltageparameters,suchasgridvoltageexperimentallyvalidated.

amplitudeandfrequency,canbemonitored.Thegridvoltage

II.ORTHOGONALSYSTEMGENERATIONStepResponse

12

Theproposedmethodofcreating

anorthogonal

systemisk0.3

k=1depictedinFig.2.Asoutputsignals,

twosine

waves(v'and

1L_--k-3

l

qv')with

aphaseshiftof900

aregenerated.The

component

0~8

V'hasthesamephaseandmagnitude

asthefundamentalof

theinputsignal(v)[7].

,

06

VE

+

-S

_v'Kr:

qv

Ix&

qvJ.........................°00.020.04

0

06OM08

0A0A2

SecondOrder__

ner~Ii~edI.

t_rator

Time(sec)

IJVen|w~~~~~~~~~~~~~~~(b)

Fig.

2.General

structureof

asingle-phase

PLL

Fig.3.BodePlot(a)andStepResponse(b)oftheclose-loop

Thepresentedstructureisbasedonsecondordertaseucin(dtdfeetvlefgi

generalisedintegrator(SOGI),whichisdefined

as[7]-[11]:

Gl=2cos

(2

Thetuning

oftheproposed

structureisfrequency

s2

+(1

dependent,thusproblems

canoccurwhengridfrequencyhas

-whereco

representsthe

resonancefrequencyofthe

SOGI.fluctuations.As

aconsequence,

anadaptivetuning

ofthe

T

rsdv'

dstructureinrespecttoitsresonancefrequencyisrequired.

Theclosed-looptransferfunctions(HdL

and

dVTherefore,

the

resonancefrequency

valueoftheSOGI

is

-qv'

ofthepresentedinFig.

defmedadjustedbytheprovidedfrequencyofthe

PLLstructure.

Hq=-)ofthestructurepresentediFig.

2aredefinedas:

Theproposedmethodforcreatingtheorthogonalsystem