Nâng cao khả năng khắc phục lỗi lưới không đối xứng của hệ thống phát điện chạy bằng sức gió

TAP CHi KHOA HOC & CONG NGHE CAC TRlTCfNG DAI H(^KI U

NANG CAO KHA NANG KHAC PHyC LOI LlTdl KHONG D6 I XTTNG

CUA HE THONG PHAT DIEN CHAY BANG StTC GIO

IMPROVING THE RESPONSE OF WIND POWER PLANTS AGAINTS SYMMETRICAL AND

UNSYMMETRICAL GRID FAULTS

Nguyin Thj Mai Huffng, Bang Danh HoSng Nguyen Phung Quang

Tnrdng Dai hoc Kv thugt Cong nghiep Thdi Nguyen Tru&ng Dgt hgc Bdch khoa Hd Noi

Den Tda soan 27-8-2012, chap nhan dang 05-12-2012

TOM TA T

Bdi bdo nay trinh bdy cdc kit qud nghidn ciru vi cdc bidn phdp nang cao khd ndng khdc phi^c

l6i lu&i dit xirng vd khdng doi xirng trong cdc hd thdng phdt didn chay sire gid Khi xay ra loi Iw&i thi

bg bien ddt phia mdy phdt dirac dieu khien ngirng Idm vigc, cdc ddy quin rotor dwac noi tat qua m&

hd thong dign tr& tidu tdn dd duy tri qud trinh van hdnh ding bd cua mdy phdt v&i Iw&i phan phk

Trong khi 66 hd biin ddi phia Iw&i dwgc dieu khiin de phdt cdng suat phdn khdng h5 trQ lu^i. Cdc kit

qud md phdng dwg>c thi/c hien trong mdi trwang Matlab - Simulink - Plecs cho thiy vigc dp dgng bidn

phdp khdc phgc loi Iw&i ndi trdn da gidp cho hd thing c6 cdc ddp irng qud dd tit khi xdy ra l5i Iw&i d6i

xii'ng va khong dii xu'ng.

ABSTRACT

The paper presents the investigation results of methods to improve the response of wind power

plants against the symmetrical and unsymmetrical grid faults During grid faults the generator-side

inverter stops its operation and the rotor circuit will be connected with a damping resistance bank to

detect the power electronics During this time the frontend-converter continues its controlled operation

to generate the reactive power to maintain the grid. The simulation results using Matlab - Simulink￾Plecs prove that the mentioned methods would improve the grid response in cases with symmetrica!

and unsymmetrical grid faults

Keywords. Wind power plant, doubly-fed induction generator, passivity-based control, frontend

converter, unsymmetrical grid fault, ride-through capability

1. TONG QUAN

Ngay nay, cac he thdng tudc-bin gid hien

dai thudng la cac he thdng cd tdc dp thay ddi su

dung cac may phat khdng ddng bd ngudn kep

(MPNK). Cac may phat nay dugc ndi vdi cac

bp bien ddi d ca hai phia rotor va ludi. Ben

canh kha nang lam viec vdi dai bien thien toe

do ldn xung quanh Idc do ddng bp thi mdt uu

diem quan trpng ciia cac MPNK la d chd cac bp

bien ddi chi can dam bao kha nang lam vi?c vdi

khoang 30% cdng suat tdng cua may phat. Dieu

nay cho phep giam dugc dung lugng ciia cac bg

bien ddi va gia thanh cua toan bd he thdng [1]-

[3].

Tuy nhien, cac he thdng may phat siic gid

sir dung MPNK cd nhugc diem la rlt nhay doi

vdi cac nhieu loan ludi, dac biet la khi dien ap

ludi giam tir O.l - 0.9 dan vj tuang ddi ciia dien

ap ludi danh dinh trong khoang thdi gian tir 0.5

chu ky cho den 1 phiil. Hien tugng nhu vay cdn

dugc gpi la sap ludi [4,5]. Mpt trong cac giai

phap de bao ve he thdng khi xay ra sap ludi la

cat may phat ra khdi ludi. Trong trudng hgfp

nhu vay, he thdng tudc-bin gid khdng cd kha

nang khdi phue lai ngay l^p tuc tinh trang lam

viec nhu liic trudc khi \a\ ra su cd va phai hoa

ddng bd lai. Mat khac, khi tdng dung lugng cua

cac may phat sue gid trong he thdng phan phoi

ngay cang gia tang thi viec cat cac may phat ra

khdi ludi mdt each khdng cd kiem soat co the

cdn lam tdi te han tinh trang sap ludi do cac

may phat ngimg cung cSp dien nang cho luoi,

Tham chi cdn cd the dan den viec lam mdt on

djnh he thong ludi phan phoi [6],[7].

Kht he thdng phan phdi bj sy cd sap lucfi

se lam gia tang manh dong dien trong cac cupn

day cua MPNK. Do lien he giua tir trudng

stator va rotor, ddng dien ldn nay se tac dpng

vao mach rotor va bd bien ddi cd the dan den

viec pha hdng bg bien ddi neu khdng cd cac

bien phap bao ve bg bien ddi. Mgt nghien ciiu

trong [8] da chi ra rang khi MPNK chju tac

ddng ciia nhieu dien ap luai se gay ra dao dpng