Configurations Systematis HVDC (High - Voltage Direct Current)

HVDC, quod est abreviatura pro High - Voltage Direct Current, est methodus valde efficientis ad transmissionem potentiae electricae per longas distancias, notabiliter minuens perdas potentiae comparata cum traditionali transmissione currentis alternantis (AC). Systema HVDC potest in variis configurationibus implementari, unaquaeque ad specifica requisita operationalia accommodata. Hoc articulus praebet brevem conspectum principium typorum configurationum systematis HVDC.

Systemata HVDC Back - to - Back

In configuratione back - to - back (B2B) HVDC, rectificator et inversor, qui sunt elementa clavaria converteris, intra unam stationem terminalem locantur. Haec duo elementa converteris directe connectuntur inter se. Prima functio huius configurationis est ut duos separatos systemata AC potentiae connectat. Id facit primum convertendo potentiam AC incoming in DC per rectificatorem et statim transformando potentiam DC in AC per inversorem.

Systemata HVDC Back - to - Back (Continuatio)

Setup back - to - back HVDC installatur intra unum cubiculum et servit ad interconectandum duos systemata AC asynchrona. Propter connectionem directam back - to - back rectificatoris et inversoris, non est necessitas lineae transmissionis DC. Ad minimizandam numerum thyristorum in serie conectorum, tensio media DC intencionaliter ad nivellum parvum retinetur. Interim, rating currentis huius configurationis potest ad millia amperorum pervenire.

Huiusmodi systema HVDC est specialiter utilis ad coniungendum duos systemata AC asynchrona in sequentibus casibus:

• Quando duae systemata AC vel retes operantur ad differentes frequencias.

• Quando duae systemata habent eandem frequentiam sed exhibent differentiam phasialis.

Systema HVDC Bipunctuale

In configuratione bipunctuali HVDC, sunt duae distinctae stationes terminales, unaquaeque functionans ut station converteris. Una station habet rectificatorem, altera autem continet inversorem. Hae duae terminales connectuntur per lineam transmissionis HVDC, efficaciter transmittendo potentiam electricam per longas distancias. Huiusmodi setup est designatus ad superandas limites traditionalis transmissionis AC pro longo transferendi potentiae, utilitatem potentiae DC ad minimum perdas et ad augendam efficientiam transmissionis per vastas regiones geographicas.

Systema HVDC bipunctuale praebet connectionem directam inter duos punctos sine ullis lineis transmissionis parallelis vel tapibus intermediis per lineam transmissionis. Haec characteristica dedit sibi nomen alternativum, transmissionem potentiae puncto - ad - punctum. Id optime adaptatum est ad applicationes supply potentiae inter duos locos geographicamente distantia.

Unum ex notabilibus beneficiis systematis HVDC bipunctualis est sua non necessitas circuiti breaker HVDC. In eventu maintenance vel quando eliminatur fault, circuiti breakers AC lateris AC possunt utilizari ad de - energizare lineam DC. Comparato cum circuiti breakers DC, circuiti breakers AC habent designum simplicius et veniunt ad pretium minus, faciens systema HVDC bipunctuale plus economicum et facilius ad maintinendum.

Systema Multi - Terminal DC (MTDC)

Systema Multi - Terminal DC (MTDC) repraesentat configurationem HVDC complexior. Utilizat plures lineas transmissionis ad establishendas connections inter plures quam duos punctos. Huiusmodi setup continet plures stationes terminales, unaquaeque equipata suo proprio converter, omnes interconnectatas per rete lineale transmissionis HVDC. Intra hoc rete, quidam converteres functionant ut rectificatores, convertentes potentiam AC in DC, alii vero operantur ut inversores, transformantes potentiam DC rursus in AC pro distributione ad onera. Principium fundamentale systematis MTDC est ut totalis potentia a stationibus rectificatoribus suppeditata aequalis sit potentiae combinatae receptae a stationibus inversorum (onera), assecurans fluxum potentiae balancatum et efficientem per rete interconnectatum.

Systema Multi - Terminal DC (MTDC) (Continuatio)

Rete MTDC est analogum gridae AC in flexibilitate, sed offert advantagium unicam: posse precise controlare fluxum potentiae intra rete distributum DC. Tamen, haec functionalis augmentata venit ad pretium incrementi complexitatis, faciens systema MTDC significanter intricatiorem quam configurationem bipunctualis HVDC.

In setup MTDC, confidere in circuiti breakers AC lateris AC non est factibile. Diversum ab systema bipunctualis, uti circuiti breaker AC de - energizaret totum rete DC potius quam isolaret solam lineam fautam vel requirientem maintenance. Ad hoc, systema MTDC necessitat plures componentes switchgear DC, sicut circuiti breakers. Hi specialis circuiti breakers DC sunt designati ad secure de - energizare circuits vel isolare partes speciales durante operationes maintenance vel quando eliminatur fault, assecurans stabilitatem et fiduciam rete.

Maintenere balance systematis est cruciale in systema MTDC. Totalis currentis a stationibus rectificatoribus suppeditatus debet exacte correspondere currenti consumpto a stationibus inversorum. Quando est surge subito in demanda potentiae ab unoquoque statione inversorum, output potentiae DC debet adaugari secundum ad satisfaciendum incremento oneris. Durante hoc processus, est essenti monitorare et controlare accurate et voltage suppeditatum et operationem inversorum ne overload, quod potest ducere ad failure systematis.

Unum ex principiis fortibus systematis MTDC est eorum fiducia durante outages coactas. In eventu power failure imprevista in una stationum generationis, systema potest celeriter reroutare potentiam per stationes converteris alternativas, minimizando disruptionem ad supply potentiae overall.

Applicationes MTDC

• Integratio Energiarum Renovabilium: Facilitat connexionem plures farmas energeticae basatae in DC ad varias gridas potentiae, permittens distributionem efficientem energiarum purarum.

• Potentia Venti Offshore: Permittit connexionem plures farmas venti offshore ad gridam potentiae onshore, superando difficultates associatas ad transmitendum magnas quantitates potentiae per longas distancias ab locis remotis offshore.

• Transfer Bulk Potentiae: Permittit transferre potentias largas scalas a plures stationibus generationis AC remotis ad plures centra oneris, optimizans distributionem potentiae per vastas regiones.

• Interconnection Grid: Permittit interconnectionem inter duos systemata AC asynchrona, augmentans stabilitatem gridae et capabilitys exchange potentiae.

• Reallocatio Supply Potentiae: Permittit reallocationem supply potentiae in eventu failure potentiae in stationibus generationis individualibus, assecurans delivery continuam potentiae ad consumers.

• Support Network AC: Potest supplere potentiam additional ad network AC heavy loaded utendo single rectifier et plures inversores ad injectare potentiam in gridam AC, alleviating congestion et improving overall performance gridae.

• Flexibilis Power Tapping: Offert flexibilitatem ad tapping potentiae in plures punctos intra rete, adapting ad diversa demandas potentiae et requirementa distributionis.

Systemata MTDC possunt categorizari in duos primarios types:

Systema MTDC Serie

In configuratione MTDC serie, plures stationes converteris connectuntur in serie, sicut componentes in circuitu electrico serie. Characteristica definitiva huius setup est quod currentis perfluens per unicam stationem converteris manet idem, sicut est set ab una statione. Tamen, drop tensionis distribuitur inter stationes converteris, unaquaeque station experiens partem drop tensionis totalis per rete series - connected.

Systema MTDC Serie (Continuatio)

Systema MTDC serie potest considerari ut version extensa systematis bipunctualis HVDC, incorporans plures stationes converteris connectas in serie, sicut illustratur in diagrammate adjacente. Usualiter, stationes converteris in setup MTDC serie habent capacitate minor comparata cum his usatis in systematis MTDC parallelis.

Hoc systema commoniter employat links DC monopolar, ubi linea DC est grounded at unum punctum specificum. Ad safeguarding contra surges electricas transientes, capacitor grounding potest installari in aliis punctis per lineam ut measure protectivum additivum.

Insulation coordination in systema MTDC serie presentat significantes challenges propter variabiles tensiones DC in unaquaque statione. Mechanismus controlis fluxus potentiae in systema MTDC serie est intricatius comparato cum illo in systema MTDC parallelo. In systema MTDC parallelo, fluxus potentiae potest regulari per injectionem currentis in lines specificas, at in systema MTDC serie, controlis fluxus potentiae dependet ad adjustandum tensionem in unaquaque statione terminali.

Reversio fluxus potentiae in systema MTDC serie potest facile accompliri utendo both Voltage Source Converters (VSC) et Current Source Converters (CSC). Tamen, quando occurrat fault vel maintenance scheduleta sit requireta pro linea specifica, totum rete DC experietur blackout. Similiter ad systema HVDC bipunctuale, circuiti breakers lateris AC utuntur ad de - energizare rete DC. Expanding systema MTDC serie quoque posit difficulties. Installando novas stationes terminales necessitat completum blackout rete, quia rete DC ring - shaped debeat scindier at installation point, disrupting supply potentiae ad all other stations along path.

Systema MTDC Parallela

In systema MTDC parallela, plures stationes converteris functionantes ut inversores vel load stations connectuntur ad singulam stationem converteris actuante ut rectificator. Hic rectificator station supplies potentiam ad totum rete DC. Analogous ad circuitum electricum parallelum, tension remains constant across all inversores vel load stations, with its value set by one of converter stations. In contrast, supply current varies according to power demand at each station. To maintain balanced current supply, current is dynamically adjusted in response to power requirements of individual load stations. Generally, terminal stations in parallel MTDC system have higher capacity than those in series MTDC network.

Systema MTDC Parallela (Continuatio)

Reversio potentiae in systema MTDC parallela potest accompliri per either voltage reversal or current reversal methods. When using voltage reversal, which is typically associated with Current Source Converter (CSC) - based terminal stations, it has an impact on all converter stations. As a result, a highly sophisticated control and communication system must be implemented among these converters to manage this effect. On the other hand, if power reversal is achieved using the current reversal technique, which is often associated with Voltage Source Converter (VSC) - based terminal stations, the process is much more straightforward to execute. This is the primary reason why VSCs are favored over CSCs in parallel MTDC systems.

In a VSC - based MTDC system, since the voltage remains constant, the power rating of the terminal station is determined by the current ratings of the valve converter. This configuration offers a significant advantage in terms of power flow control within the DC network. It can precisely regulate the power flow by injecting current into specific lines, which is a more convenient approach compared to the power control mechanism in series systems that rely on voltage control at each station.

One of the most notable features of the parallel MTDC system is its resilience in the face of faults. If a fault occurs in any of the terminal stations, the remainder of the DC network remains unaffected. However, to isolate the specific DC lines associated with the faulty station, a separate DC circuit breaker is required. Additionally, during the expansion of the DC network, there is no need to interrupt the power supply. This is because new terminal stations can be installed in parallel with the existing lines, ensuring seamless integration without disrupting the ongoing power distribution.

Another advantage of the parallel MTDC system is its relatively simple insulation coordination compared to a series system. Due to the constant voltage across the network, the insulation requirements are more straightforward to manage.

The parallel MTDC system can be further classified into two categories:

Systema MTDC Radial

Systema MTDC radial est specificus type configurationis MTDC parallela. In hac setup, si est break in transmission line vel removal of one link, it will lead to interruption of power supply to one or more converter stations. This characteristic makes the radial MTDC system somewhat vulnerable to single - point - of - failure scenarios, as any disruption in the transmission line can have a direct impact on the power supply to certain parts of the network.

Provided figure depicts a configuration where four inverter stations are connected to a single rectifier station. In this setup, it is evident that if there is a break in any one of the lines, it will inevitably result in the interruption of power supply to at least one terminal station. This vulnerability makes the radial MTDC system less reliable when compared to the Mesh or Ring type MTDC systems.

Systema MTDC Mesh (Ring)

In a Mesh or Ring MTDC system, the inverter (load) stations are interconnected with a single rectifier station in a mesh or ring - like formation. One of the key advantages of this configuration is that even if there is a break in a single transmission line or the removal of one link, it does not lead to the interruption of power supply to any of the inverter stations. The subsequent figure clearly illustrates such a mesh or ring MTDC system. This inherent resilience to line failures makes the Mesh or Ring MTDC system a more reliable option for power transmission and distribution in certain applications, as it can better withstand disruptions and ensure continuous power supply to the connected load stations.

As illustrated, in a mesh or ring - type MTDC system, the removal of any single link does not disrupt the power supply to any converter station. Instead, the electrical power is automatically rerouted through alternative links within the network. This seamless redirection is made possible by the interconnected nature of the mesh or ring configuration. However, it is crucial to note that these alternative links must be meticulously designed to handle the increased power transmission while minimizing power losses.

The absence of power interruptions in the mesh - type MTDC system is a significant advantage. It ensures a continuous and stable power supply, even in the face of unexpected link failures. Consequently, a parallel - connected mesh - type MTDC system offers superior reliability compared to its parallel - connected radial - type counterpart. The radial system's susceptibility to power outages due to single - link disruptions pales in comparison to the mesh system's robust ability to maintain power flow under similar circumstances, making the mesh or ring - type MTDC system a preferred choice for applications where uninterrupted power delivery is of utmost importance.