Applicatio Regulatorum Automaticorum Tensionis SVR in Reticulis Distributionis Ruralibus

1. Introducio

In recentibus annis, cum stabiliter et celeriter se nationale economia movet, crescit insigne demanda electricitatis. In ruralibus rete electrico, continuus incrementus oneris, coniunctus cum irrationabili distributione localium fontium electricitatis et limitata capacitate regulationis tensionis in principali rete, produxit multos 10 kV longos conductores—praecipue in remotis montosis regionibus aut locis debilis structurae retis—cuius radius supply superat nationales standardes. Hinc, difficile est garantire qualitatem tensionis in fine harum 10 kV lineae, factor potens non satisficit requirementis, et perditio lineae manet alta.

Owing to constraints such as limited grid construction funding and investment return considerations, it is impractical to solve all low-voltage-quality issues on 10 kV distribution feeders solely by deploying numerous high-voltage distribution substations or excessively extending the grid. The 10 kV feeder automatic voltage regulator introduced below offers a technically viable solution for addressing poor voltage quality on long-distance distribution lines with extended supply radii.

2. Principium Operativum Regulatoris Tensionis

Regulator tensionis SVR (Step Voltage Regulator) constat ex circuitu principali et controller tensionis. Circuitus principalis continet autotransformator triphasicus et commutator tap on-load (OLTC), ut demonstratur in Figura 1.

Systema winding regulatoris includit shunt winding, series winding, et control voltage winding:

• Series winding est multitap coil inter input et output via different contacts of the tap changer; it directly regulates the output voltage.

• Shunt winding serves as the common winding of the autotransformer, generating the magnetic field necessary for energy transfer.

• Control voltage winding, wound over the shunt winding, acts as a secondary of the shunt coil to supply operating power for the controller and motor, as well as provide voltage signals for output measurement.

Principium operativum est hoc: Per connectionem taps series winding ad differentes positiones commutatoris tap, ratio turns inter input et output windings mutatur per controlled switching of tap positions, thereby adjusting the output voltage. Depending on application requirements, on-load tap changers are typically configured with either 7 or 9 tap positions, allowing users to select the appropriate configuration based on actual voltage regulation needs.

Ratio turns inter primary et secondary windings regulatoris est consistent cum that of a conventional transformer, i.e.:

3.Exemplum Applicationis
3.1 Conditiones Lineae Actuales

Quaedam 10 kV distributiva linea habet longitudinem main feeder 15.138 km, constructa duobus conductor typis: LGJ-70 mm² et LGJ-50 mm². Capacitas totalis distributionis transformatorum along the line est 7,260 kVA. During peak load periods, the voltage on the 220 V side of distribution transformers in the middle-to-end sections of the line drops as low as 175 V.

Conductor LGJ-70 habet resistance 0.458 Ω/km et reactance 0.363 Ω/km. Therefore, the total resistance and reactance from the substation to Pole #97 on the main feeder are:
R = 0.458 × 6.437 = 2.95 Ω
X = 0.363 × 6.437 = 2.34 Ω

Based on the distribution transformer capacity and load factor along the line, the voltage drop from the substation to Pole #97 on the main feeder can be calculated as

Symbols used are defined as follows:

• Δu — voltage drop along the line (unit: kV)

• R — line resistance (unit: Ω)

• X — line reactance (unit: Ω)

• r — resistance per unit length (unit: Ω/km)

• x — reactance per unit length (unit: Ω/km)

• P — active power on the line (unit: kW)

• Q — reactive power on the line (unit: kvar)

Thus, the voltage at Pole #97 on the main feeder is only:
10.4 kV − 0.77 kV = 9.63 kV.

Similarly, the voltage at Pole #178 can be calculated as 8.42 kV, and the voltage at the line end is 8.39 kV.

3.2 Proposed Solutions

To ensure voltage quality, the primary voltage regulation methods in medium- and low-voltage distribution networks include:

• Aedificium novae substationis 35 kV ad breviandum radius alimentationis 10 kV.

• Substitutio conductorum maioribus sectionibus transversalibus ad minuendum onus lineale.

• Installatio compensationis potentiae reactivae lineae—tamen, haec methodus minus efficax est pro longis lineis cum oneribus magnis.

• Installatio automatice regulatoris tensionis feeder SVR, quae praebet altam automationem, excellentem performance regulationis tensionis et flexibile deployment.

Infra, tres solutiones alternativae ad meliorem qualitatem tensionis in fine lineae in feeder 10 kV "Fakuai" comparantur.

3.2.1 Aedificium Novae Substationis 35 kV

Eventus expectatus: Nova substation significanter breviabit radius alimentationis, elevabit tensionem in fine lineae et meliorabit qualitatem generalis potentiae. Licet multum efficax, haec solutio postulat investitionem substantialem.

3.2.2 Modernizatio Feeder Principalis 10 kV

Modificatio parametrorum lineae principaliter involvit incrementum sectionis transversalis conductorum. In regionibus sparsim inhabitatis cum lineis parvorum conductorum, perditio resistiva dominatur decrescendo totali tensionis; itaque, reducendo resistentiam conductorum praebetur notabilis melioramentum tensionis. Cum hac modernizatione, tensio in fine lineae potest elevari ab 8.39 kV ad 9.5 kV.

3.2.3 Installatio Automatice Regulatoris Tensionis Feeder SVR

Unus automaticus regulator tensionis 10 kV installatur ad solvendas quaestiones tensionis basse infra polem #161.
Eventus expectatus: Tensio in fine lineae potest elevari ab 8.39 kV ad 10.3 kV.

Analyse comparativa ostendit Optionem 3 esse maxime oeconomicam et practicam.

Systema automatice regulationis tensionis feeder SVR stabilizat tensionem output regnando rationem spira unius autotransformatoris triphasici, praebens plura praeclara benefici:

• Totaliter automatica, regulationis tensionis sub onere.

• Usus autotransformatoris triphasici stellato connecti—compacti magnitudinis et capacitas (≤2000 kVA), aptus ad installationem inter poles.

• Typica range regulationis: −10% ad +20%, sufficiens ad satisfaciendas requisitiones tensionis.

Ex calculis theoreticis, recommendatur installatio unius automatice regulatoris tensionis SVR-5000/10-7 (0 ad +20%) in feeder principali. Post installationem, tensio in pole #141 potest elevari ad:

U₁₆₁ = U × (10/8) = 10.5 kV

ubi:

• U₁₆₁ = tensio in puncto installationis regulatoris post commissionem

• 10/8 = maxima ratio spira regulatoris cum adjustment range 0 ad +20%

Operatio in campo confirmavit systema SVR fideliter sequi variationes tensionis input et maintinere stabilem tensionem output, demonstrans effectivitatem probatam in mitigatione tensionis basse.

3.2.4 Analyse Benefici

Comparata ad aedificium novae substationis vel substitutionem conductorum, deployatio automatice regulatoris tensionis SVR significanter reducit expendituras capitalis. Non solum elevat tensionem lineae ad satisfaciendas normas nationales—praebens fortes beneficia socialia—sed etiam, sub conditionibus constantis oneris, reducit currentem lineae elevando tensionem, ita minuens perditationes lineares et efficiens salva energiarum. Hoc augit economicam efficientiam utilitatis.

4. Conclusio

Pro retibus distributionis ruralibus in regionibus limitati futuri oneris—praecipue illis carentibus proximis fontibus potentiae, cum longis radiis alimentationis, altis perditationibus linearibus, oneribus magnis et sine planis de constructione substationum 35 kV in tempore proximo—usus automatice regulatorum tensionis feeder SVR praebet alternative compellentem. Id permittit differendum vel eliminationem aedificationis substationis 35 kV dum efficaciter solvit qualitatem bassem tensionis et reducit perdитии энергии. Учитывая, что инвестиционные затраты на SVR-решение менее одной десятой стоимости новой подстанции 35 кВ, это решение приносит значительные социальные и экономические выгоды и настоятельно рекомендуется для широкого внедрения в сельских электрических сетях.