Coordinatio Reclosorum et Sectionalizatorum in Reticulis Distributionis

Coordinatio Reclosorum et Sectionalizatorum in Reticulis Distributionis

Reclosores automatici et sectionalizatores automatici (breviter reclosores et sectionalizatores) sunt dispositiva automatizata completa et fidelia. Non solum possunt eliminares fideles et prompte defectus transitorios, sed etiam minuere ambitum intermissionis electricitatis causatum per defectus permanentes. Quoniam reclosores et sectionalizatores adhibentur in reticulis distributionis, possunt selective et efficaciter eliminare defectus transitorios ut prohibeant eos ab evolvendo in defectus permanentes, et etiam isolare defectus permanentes, sic magnopere meliorantes fidem praebitionis electricitatis.

1. Functiones et Characteristicae Reclosorum Automaticorum

Recloser automaticus est dispositivum automatizatum cum functionibus protectionis, detectionis, et controlis. Habet curvas characteristicarum tempore-currentis inversae cum diversis limitibus temporum et functionem multireclosing. Est novus genus apparati electrotechnici electromechanici qui integra circuitum interruptoris, protectionem relais, et mechanismum operationis. Potest automatica detegere currentem per circuitum principalem reclosoris. Cum deficiens currentis confirmatur, ipse automatica interrompet deficiens currentem secundum protectionem tempore-currentis inversam post certum tempus et reclose multoties ut restituat praebitionem electricitatis lineae. Si defectus est transitorius, linea redibit ad normalem praebitionem electricitatis post reclosing reclosoris; si defectus est permanens, post reclosorem completum praedeterminatum numerum operationum reclosing (solito 3 vices) et confirmationem quod defectus lineae est permanens, ipse automatica claudet et non praebet electricitatem lineae deficiente donec defectus eliminatur et clausura reclosing manualiter solvitur ut restituat statum normalem.

Functiones et characteristicae specificae reclosorum sunt sequentes:

• In quaestione performance interruptoria, reclosores habent functiones sicut interrumpe currentes short-circuit, facere operationes multireclosing, eligere coordinationem sequentialiter protectionis characteristicarum, et reset systematis protectionis.

• Recloser principaliter constat ex camera arc-extinguendi, mechanismo operationis, systemate controlis, bobina closing, et aliis partibus.

• Recloser est dispositivum controlis localis. In quaestione characteristicae protectionis et controlis, habet functiones sicut detectio sui ipsius defectus, iudicium naturae currentis, executionem operationum commutationis, et potest redire ad statum initiale, memorare numerum operationum, et complere electionem sequentiarum operationum sicut closing lockout. Pro reclosoribus adhibitis in lineis, non est additus dispositivus operationis, et potentia operativa sua directe sumitur ex linea alta tensionis. Pro his adhibitis in substationibus, est supplys electricitatis bassae tensionis pro apertura et clausura mechanismi operationis.

• Reclosores conveniunt ad modos installationis lineae distributionis exteriores et possunt instari vel in substationibus vel in variis columnis.

• Numerus operationum locking, characteristicae velocitatis opening, et sequentia operationum reclosing diversorum generum reclosorum generaliter differunt. Eorum characteristica typica quattuor operationum breaking et tres operationum reclosing est: break → (T₁) close - break → (T₂) close - break → (T₃) close - break, ubi T₁ et T₂ sunt regendae et variant secundum diversos producta. Potest regulare numerum operationum reclosing et intervallum temporis reclosing secundum necessitates durante operatione.

• Interruptio defectus inter phaseas reclosorum adhibet characteristica tempore-currentis inversam ad cooperando cum characteristica ampere-temporis fusorum (sed interruptio defectus terre electronic controlled reclosorum generaliter adhibet tempus definitum). Reclosores habent duos genera curvarum characteristicarum ampere-temporis: celerem et tardam. Solito, prima operatio breaking agit secundum curvam celerem, ita ut possit interrumpere currentem defectus intra 0.03 - 0.04s. Pro operationibus breaking subsequentibus, diversas curvas characteristicarum ampere-temporis possunt eligi secundum necessitates coordinationis protectionis.

2. Functiones et Characteristicae Sectionalizatorum Automaticorum

Sectionalizer est dispositivum protectionis automaticum adhibitum in systemate distributionis ad isolandum sectionem lineae defectivi. Solito adhibetur in cooperatione cum reclosore automatico vel interruptore circuiti. Sectionalizer non potest interrumpere currentes defectus. Quando defectus occurrit in linea sectionata, backup protection recloser vel interruptor circuiti sectionalizatoris operatur, et functio counting sectionalizatoris incipit accumulare numerum operationum tripping reclosoris. Quando sectionalizer attingit praedeterminatum numerum operationum recordatarum, ipse automatica trippabit in momento quo dispositivum backup tripit ad disiungendum sectionem lineae defectivi. Recloser recloses iterum ut restituat praebitionem electricitatis aliis lineis. Si numerus operationum tripping reclosoris non attingit praedeterminatum numerum operationum recordatarum sectionalizatoris et defectus eliminatus est, computatio sectionalizatoris automatica desinet post certum tempus, rediens ad statum initiale.

Sectionalizatores dividuntur in duo genera secundum numerum phasearum: uniphase et triphase. Secundum modum controlis, dividuntur in hydraulice controlatos et electronic controlatos. Sectionalizatores hydraulice controlati utuntur controllo hydraulico ad computationem, sectionalizatores electronic controlati utuntur computatione electronica. Functiones et characteristicae principales sectionalizatorum automaticorum sunt sequentes:

• Sectionalizatores habent functionem automaticam computandi numerum operationum tripping dispositivi protectionis superioris.

• Sectionalizer non potest isolare currentes defectus, sed potest disiungere defectus lineae permanentes in cooperatione cum reclosore. Quoniam potest isolare currentes pleni oneris, potest adhiberi ut commutator manuale oneris.

• Sectionalizer potest facere tripping automaticum et manuale. Post tripping, est in statu clauso et potest restaurare praebitionem electricitatis tantum per closing manuale.

• Sectionalizer habet coil tripping connectum in serie in circuitu principali, et minimum currentem operativum potest mutari per substitutionem coil.

• Non est connexio mechanica vel electrice inter sectionalizer et recloser, nec restrictio loci installationis eius.

• Sectionalizer non habet characteristica ampere-temporis, ita ut habeat specialia beneficia in usu. Sicut adhiberi potest in occasionibus ubi curvae characteristicarum duorum dispositivorum protectionis valde propinquent, sic compensans defectum quod coordinatio non semper potest assequi etiam addendo gradus in systemate protectionis multi-level.

3. Cooperatio Inter Reclosores et Sectionalizatores

Operatio cooperativa reclosorum et sectionalizatorum potest realizare eliminationem defectus transitoriorum, isolationem regionum defectus permanentium, et assecurare praebitionem normalem segmentorum lineae non-defectivi. Owing to the different functions of reclosers and sectionalizers, first, the section layout of the line should be reasonably determined according to the system operation conditions to improve the degree of distribution line automation and power supply reliability. Its typical structure is shown in Figure 1.

Theoretically speaking, each branch point on the line should be considered as a sectioning point. In this way, even if a permanent fault occurs on a relatively short branch line, it can be selectively sectioned, and the normal power supply of other sections can be maintained. However, due to economic and operating condition constraints, it is often impossible to achieve this. Therefore, it is necessary to proceed from reality and adapt to local conditions. Both reclosers and sectionalizers are intelligent devices with many advantages such as a high degree of automation. However, they can only play their roles when used in correct coordination. Therefore, the following coordination principles should be followed:

• Sectionalizer must be connected in series with the recloser and installed on the load side of the recloser.

• Backup recloser must be able to detect and act on the minimum fault current within the protection range of the sectionalizer.

• Starting current of the sectionalizer must be less than the minimum fault current within its protection range.

• Thermal stability rating and dynamic stability rating of the sectionalizer must meet the requirements.

• Starting current of the sectionalizer must be less than 80% of the minimum tripping current of the backup protection and greater than the peak value of the expected maximum load current.

• Number of recording times of the sectionalizer must be at least 1 time less than the number of tripping times of the backup protection before locking.

Memory time of the sectionalizer must be greater than the total accumulated fault breaking time (TAT) of the backup protection. Total accumulated time (TAT) of the backup protection action is the sum of the fault current-carrying time of each fault in the backup protection sequence and the reclosing interval. Since the sectionalizer does not have an ampere-time characteristic, the coordination between the recloser and the sectionalizer does not require the study of protection curves.

Backup protection recloser is set to lock after 4 tripping operations. These operations can be a combination of any fast and slow (or delayed) operation modes, and the setting number of times for the sectionalizer is selected as 3 counts. If a permanent fault occurs on the line on the load side of the sectionalizer, the sectionalizer will open to isolate the fault before the 3rd reclosing of the recloser, and then the recloser will supply power to the non-faulty line. If there are other serially configured sectionalizers, the number of locking times they are set with should be smaller level by level.

When a fault occurs on the line on the load side of the last-stage sectionalizer, the recloser acts. The serially connected sectionalizers all record the number of times the recloser breaks the current. After the last-stage sectionalizer reaches the number of action times, it trips to isolate the fault, and then the recloser recloses to connect the non-faulty line and restore normal power supply. The sectionalizers that do not reach the number of counting times will reset to the initial state after the specified reset time.