CIRCUIT ARRANGEMENT FOR COMPENSATION OF FAST CHANGING REACTIVE POWER, IN PARTICULAR ON THE POINT OF CONSUMERS, WHICH GENERATE HARMONICS

Abstract: The essence of the circuit arrangement lies in that the harmonic filters anyway needed for the suppression of the harmonics are connected to the bus via a transformer with a variable voltage ratio. The secondary coil of the transformer with the variable voltage ratio is provided with taps, which are connected to the harmonic filters via the under-load-switch-over-unit. After a switch-over process the reactive power of the filters is changing without simultaneous change of the resonance frequency and efficiency of filtering. The application of the method reduces investment costs and involves savings in energy.

Description: CHICU Γ ΛSH/-ιrGirnτϊ FO CG?.?I;I.5ΛI-IG:I OP PASS CΪIΛΪΪCΣITG ItDACEIVJB PO:/I5R, 11? P -T2ICu ,A Oil 2iϊE 2POH.2 C? CG GU- iiώiS, WHICH Giϋϊ--IlAϊiϊ IIAUi 0 -IC3 2 θ circuit e raarcacat according to tho inven ior- ic well suitable -for coτ.'.per.- at oιι the Tost chancing reactive power of non-linear - accordingly upper harmonics generating — consumers* Circuit angeme ts avo boon woll known, w ic ore v/eϊl suitable or tho compensation cf feat • ch ^ius reactive power s however, those circuit ar- rc.n_ ~ c ~ .QQ.ta in itoclves are not sufficient in'case of non-linear co sti-αe o, g e ing -harrionicc, ia ell cases cαaplansat with harmonic filters in imperative * As an * exsnple for this solution wo nay πen- tioα β εwitchable capacitor bank, however, ia this cas tho capacitor bank with a c ansins capacity nd tho supply network nay Sors. t ~ parallel resonant circuit on the frequencies 9 to which no one of the harmonic filters is tuned, resulting in undosired voltage— is- tortionα and overheating of tho frequency-sensitive consumers etc * , accordingly, this solution ia not used in case of ecasuracrs ge e at ng hornonlcs * Another solution is represented by the appli cation of nhuat-^roac or 'switched via phase-an^le cont¬ rolled thyrictors * In this case, however, control will produce further harmonics, ' ot oocurinø up-to-now, whi have to be also suppressed * A syachron-cor-pensator can bo also used or compensating tho c an^ ^ reactive power, however, thi is evon slowor, than the solutions with tho thyriαtor * 5-iιe cc-noα drewback of the solutions mention above lies in that in audition to tho harmonic filters expensive equipnents with a lar e spaco requirements a 40533-2048/Cα • needed. 9 - cc a consocue.ιcc, com ensa io the on c anging reactive power in realised only with very large invent- £j2 a conseque ce, compensation o the reactive power of jr-αller industrial ,r. '~~ <.Cap ur ng unite could not be solved, les n^ to ^-h losses in the network besides, in radial network uuάesired voltage fluctuation liny occur. S e increased less in the network can be ccq_ pεncateu only on behalf of the newer plants requiring farther investments, nt the cane tine, if reduction be— COLICS possible, e considerable capacity in tho power pla can be elease . I?luotnation of the network voltarje resu in undesired phenononn at the ocrr-unal low-volta e con- caπo β /flicker/, to avoid it, feet control of the reactive power has been ' ropesed* £he ai of the invention.is to use the hamoni filters /i*e * resonant circuits tuned to the frequency of the har-nonics/ applied v:ith the consumers generating harcionics or the ont control of the reactive owe . 'Although* by c ang ng the condensers of the . filters the control of the reactive power beco.--.es- ossib owe e 4 , simultaneously the resonance-frequency and effi • ciency cf the filtering also c ange* Aecordinsly, a cir- cnit εrranseαent is required, which changes ast the fundamental hamonic reactive power of the harmonic fil¬ ters, while the resonance frequency of the filters re- ε-aina unchanged. In accordance with the invention the aira can be achieved in such a ma e that the harmonic filters — which ere sho ing a capacitive character at tho e ¬ wor frequency — are connected via a transformer with changeable voltage- ratio to that point of the network, where cha gi g of the reactive power ia required. TTnen changing the voltage ratio, the inpeda co of tho filters having been coupled to the prix-ary aide end thus tho . OMPI ftm W1 O *•- 3 *** capacity to be s.casurc5 oil the network frequency ia cha ^ α, bu withou tho change of the value of tho -^ roooαascG .f equency * la order to bo cblo to control ast tho reac ive power, it ceo-^c to bo e e ient to 5 εwi oh-ovc? tho a s of tho control t ans o me by πoana of c -iicenduetor oleraents, a a a g eo π y c thy- ric cr o a tr ce * _ iho in en on will bo described in detail by nεan."? o. ~ c preferred oπbodisont, by the aid cf tho 10 awing onolocod / igure !/ • Ξhc uuder-load-owitch-over-uait 2 is connect to the taps of the secondary eoil lb of the transforme 1; between the coupon point Ik thereof s-ϊi tho end-poi lv of the secondary coil lb one cr sore harmonic filte 15 ' are connected the voltage of which is controlled by the undor- oad-evitch-unit 2, whereby the fu danental • harπonic reactive power of the a mo c filters 3 π-sa- εured at the prirnry coil la can be varied * In case of e. three-phaεo tranefomer the cir 20 cait arrangement is to be applied in all the three pha ses»accordingly, control of the reactive power becones possible for each phases cepαratly tc£ethor * o She circuit crranπenent according to tho . invention can be provided vjith en equipment for the 25 αutoπatic control., prcasting the application of the compensation of the fast ohαns±ng reactive power in practice * S e application of tho circuit arranscπcnt according to the invention results in coneiderable sav 30 of investment co3tσ in caae of the largo power industr conσurorσ and in the caao of c^aller nufacturins uni G g the possibility of the αat co-^pcnπatlon of tho reactive power, energy can be caved and the quality of the voltage can bo considerably improved *

Claims: V H A 2? C Λ I 1< Circuit or of feet cfcα ' -sias reactive cr.Te , in psrfc±cttlar or.. he points o:l' counte e ^^--^stins hc.r--.or-.ic 3 coritainitis a ras£.t::aT-302? τ.ith c variable voltage, ratio , εn uador- « 4 -loa « v. r :;. ch-o e -"U it for switch-over the tape, εs v.'ell ac a her- oi c filter * c h a r a c e r i s e d n t h a t between the eexrien output poiit /Ik/ of the under-load- -Gvvitc -over-iiait /2/ connec d to the tape of the eeeoiid&ry coils /lb/ of tho trasaefor^er /I/ and the end point / v/ of tho secondary coil /lb/ of the trans- f omer /!/ oae or core ha -.-iθ-i e filters /3/ -ore coanec- ted# _ OMPI ^ " wipo

Inventors: DAN ANDRAS, GESZTI P OTTO, KISVOELCSEY JENOE, DAN, ANDRAS, GESZTI, P., OTTO, KISVOELCSEY, JENOE
Applicants: BUDAPESTI MUESZAKI EGYETEM
Application year: 1982
Main classification: H02J3
IPC codes: H02J3