DK161999B

DK161999B - Method for supplying power and power supply installation for ships with propeller shaft generators

Info

Publication number: DK161999B
Application number: DK365683A
Authority: DK
Inventors: Peter Jan Fournais
Original assignee: Peter Jan Fournais
Priority date: 1981-12-17
Filing date: 1983-08-11
Publication date: 1991-09-02
Also published as: DK365683A; DK365683D0

Description

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i 5 Opfindelsen angår en fremgangsmåde til strømforsyning af skibe med mindst én synkronmaskine som akselgenerator samt et strømforsyningsanlæg til udøvelse af fremgangsmåden.The invention relates to a method for power supply of ships with at least one synchronous machine as a shaft generator and a power supply system for carrying out the method.

Der kendes forskellige fremgangsmåder og anlæg til strøm-10 forsyning af skibe, hvor der til hovedmaskinen er koblet en eller flere synkrongeneratorer ved hjælp af gear eller lignende tilkoblingsmekanismer. Skibets hovedmotor vil således via akselgeneratoren levere den nødvendige elektriske effekt, når skibet sejler. Når skibet ikke sejler, f.eks. når 15 det ligger i havn eller for anker, har man normalt såkaldte hjælpeaggregater, der består af en mindre dieselmotor, som trækker en generator og herved leverer den nødvendige elektriske effekt til skibets drift.Various methods and systems for the power supply of ships are known, in which one or more synchronous generators are connected to the main machine by means of gears or similar coupling mechanisms. Thus, the ship's main engine will supply the necessary electrical power through the shaft generator as the ship sails. When the ship is not sailing, e.g. when it is in port or at anchor, one usually has so-called auxiliary units, consisting of a small diesel engine, which pulls a generator and thereby supplies the necessary electrical power for the ship's operation.

20 Når man anvender en synkronmaskine som akselgenerator, er det nødvendigt med særlige foranstaltninger, så snart hovedmaskinen ikke holdes på det til den synkrone frekvens svarende omløbstal. Man kan f.eks. lade skibet strømforsyne af hjælpeaggregaterne, idet el-produktionen flyttes fra ak-25 selgeneratoren til hjælpeaggregaterne. Man kan også anvende et Ward-Leonard system mellem hovedmaskinen og akselgeneratoren, hvorved man kan holde generatoren på det synkrone omløbstal. Ved anvendelse af disse kendte metoder fås en u~ økonomisk driftform med unødvendigt store brændstofforbrug.20 When using a synchronous machine as a shaft generator, special measures are needed as soon as the main machine is not kept on the synchronous frequency corresponding to the synchronous frequency. One can, for example. allow the ship to power the auxiliary units, moving the electricity production from the shaft generator to the auxiliary units. You can also use a Ward-Leonard system between the main machine and the shaft generator, whereby you can keep the generator on the synchronous orbit. By using these known methods, an uneconomical mode of operation with unnecessarily high fuel consumption is obtained.

3030

Fra tysk offentliggørelsesskrift nr. 1.613.829 kendes et strømforsyningsanlæg til skibe med synkronmaskine som akselgenerator, hvor det skal være muligt at ændre et skibs driftform og styring hurtigt og effektivt, nemlig især et 35 krigsskib. Hovedvægten i denne publikation, både i beskri-German publication specification No. 1,613,829 discloses a power supply system for ships with synchronous machine as a shaft generator, where it must be possible to change a ship's mode of operation and control quickly and efficiently, namely a 35 warship. The emphasis in this publication, both in the description

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2 velse og krav, er på generatorkonstruktionen og på den glidende kobling, som tillader, at ændring i styremekanismen effektueres øjeblikkeligt. Herudover er der på side 5 i publikationen anført, at strømforsyningsnettet er opdelt i 5 tre net: a) Et første net, der er hovedforsyningsnettet for veksel strøm, idet nettet via en AC/DC ensretter og en DC/AC omsætter er forbundet til generatoren. Til dette net er 10 koblet separate enheder, der leverer manglende reaktiv effekt. Generatoren magnetiseres, så den afgiver konstant spænding, og ved hjælp af koblingsorganer styres frekvensen, så dette net leverer både konstant spænding og konstant frekvens, idet den manglende reaktive ef-15 fekt leveres af separate enheder.2 and requirements, are on the generator structure and on the sliding clutch, which permits immediate change of control mechanism. In addition, on page 5 of the publication it is stated that the power supply network is divided into three three networks: a) A first network which is the main supply network for alternating current, the network being connected to the generator via an AC / DC rectifier and a DC / AC converter. . To this grid, 10 are connected separate units that provide a lack of reactive power. The generator is magnetized to provide constant voltage, and by means of coupling means the frequency is controlled so that this grid delivers both constant voltage and constant frequency, the lack of reactive power being supplied by separate units.

b) Et andet net, der er et DC net, som leverer jævnstrøm til jævnstrømsforbrugere som f.eks. minedetektorer og lignende.b) Another DC network, which provides direct current to DC consumers such as DC. mining detectors and the like.

20 c) Et tredie net, der er et AC net, som er forbundet di rekte til særlige brugere, såsom styremaskine og andet styreudstyr til manøvrering af skibet. Sådant styreudstyr bruges kun periodisk under sejlads.20 c) A third grid, which is an AC grid, which is directly connected to special users, such as a steering machine and other control equipment for maneuvering the ship. Such steering equipment is only used periodically during sailing.

2525

Fra tysk fremlæggelsesskrift nr. 1.281.027 kendes et generatorsystem til skibe, hvor hovednettet forsynes fra en synkrongenerator via en omsætter og en vekselretter, hvor både spænding og frekvens holdes konstant.From German Patent Specification No. 1,281,027, a generator system is known for ships in which the main grid is supplied from a synchronous generator via a converter and an inverter, where both voltage and frequency are kept constant.

3030

Formålet med opfindelsen er at anvise en fremgangsmåde som angivet i krav 1' s indledning og et strømforsyningsanlæg som angivet i krav 3's indledning, hvorved der opnås store brændstofbesparelser sammenholdt med, hvad der opnås ved 35 den kendte teknik, uden at dette påfører restriktioner el- 3The object of the invention is to provide a method as set out in the preamble of claim 1 and a power supply system as set forth in the preamble of claim 3, whereby large fuel savings are achieved compared to that obtained by the prior art without imposing restrictions or restrictions. 3

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ler begrænsninger på skibets manøvreringsforhold, herunder sikring af, at der altid er tilstrækkelig elektrisk effekt til, at skibet kan manøvreres og alle strømforbrugere forsynes under alle forhold, og uden at det elektriske udstyr 5 på skibet beskadiges.lays restrictions on the ship's maneuvering conditions, including ensuring that there is always sufficient electrical power to operate the ship and supply all power consumers under all conditions and without damaging the ship's electrical equipment.

Dette opnås ved at gå frem som angivet i krav 1's kendetegnende del og under anvendelse af et strømforsyningsanlæg som angivet i krav 3's kendetegnende del.This is achieved by proceeding as set forth in the characterizing part of claim 1 and using a power supply system as set forth in the characterizing part of claim 3.

1010

Ved at fordele den elektriske effekt som angivet i beskrivelse og krav sikrer man, at spændingen og frekvensen altid passer til forbrugeren, og at ingen motorer eller andre elektromagnetiske kredsløb overforsynes, men tværtimod al-15 tid er korrekt magnetiserede på grund af sammenhængen mellem frekvens og spænding på hovednettet. Ved de kendte anlæg medfører forsøg på at holde konstant spænding, at frekvensen falder, når en vis belastning nås, og man får en overmagnetisering i alle elektromagnetiske kredsløb.By distributing the electrical power as specified in the description and requirements, it is ensured that the voltage and frequency always suit the consumer and that no motors or other electromagnetic circuits are supplied, but on the contrary, are always properly magnetized due to the relationship between frequency and frequency. mains voltage. At the known plants, attempts to maintain constant voltage cause the frequency to decrease when a certain load is reached and over-magnetization is obtained in all electromagnetic circuits.

2020

Opfindelsen forklares herefter nærmere under henvisning til tegningen, hvor fig. 1 viser en kurve over sammenhængen mellem frekvens 25 og spændinger for en akselgenerator, og fig. 2 viser en foretrukken udførelsesform for et strømforsyningsanlæg ifølge opfindelsen.The invention will now be explained in more detail with reference to the drawing, in which fig. 1 shows a graph of the relationship between frequency 25 and voltages for a shaft generator; and FIG. 2 shows a preferred embodiment of a power supply system according to the invention.

30 På tegningens fig. 1 ses en kurve A, i det væsentlige en ret linie, der inden for en del af en synkrongenerators arbejdsområde viser sammenhængen mellem frekvens og spænding, f.eks. når synkronmaskinen arbejder som akselgenerator.30 In the drawing FIG. 1, a curve A is shown, essentially a straight line, showing, within a portion of a synchronous generator's operating range, the relationship between frequency and voltage, e.g. when the synchronous machine operates as a shaft generator.

35 Kurven A er gældende for en vis belastning. Når der f.eks.35 The curve A applies to a certain load. For example, when

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4 køres med synkront omløbstal, f.eks. 50 Hz, fås der ved punkt _C en netspænding på 380 volt. Fastholdes denne frekvens ved, at hovedmotorens og dermed skrueakslens omdrejningstal fastholdes, vil spændingen falde, hvis belast-5 ningen øges, d.v.s. kurven A bevæger sig mod den øverste stiplede kurve b', og hvis belastningen formindskes, vil man få stigende spænding, d.v.s. kurven A bevæger sig mod den nederste stiplede kurve B . Tilsvarende betragtninger gælder for punktet D, der svarer til en forsyningsspænding 10 på 440 volt ved 60 Hz netfrekvens. Dette er altid tilfældet med synkrongeneratorer og muliggør desuden, at flere generatorer kan køre i paralleldrift, uden at man får problemer med at få fordelt den reaktive effekt i systemet, uden at generatorerne pendler mod hinanden.4 is run with synchronous orbital, e.g. 50 Hz, at point _C, a mains voltage of 380 volts is obtained. If this frequency is maintained by maintaining the rpm of the main motor and thus the screw shaft, the voltage will decrease if the load is increased, i.e. curve A moves toward the upper dotted curve b 'and if the load is reduced, increasing tension will be obtained, i.e. curve A moves toward the lower dotted curve B. Similar considerations apply to point D which corresponds to a supply voltage 10 of 440 volts at 60 Hz grid frequency. This is always the case with synchronous generators and also allows multiple generators to run in parallel operation without having trouble distributing the reactive power in the system without the generators commuting to each other.

1515

Kurven A på fig. 1 viser således et muligt forløb, f.eks. svarende til 80% motoreffekt, altså når skibet sejler lange stræk. Man sejler sjældent med mere end 80% motoreffekt, da dette i hovedsagen blot vil give øget slitage og oliefor-20 brug, der slet ikke står i økonomisk forhold til den beskedne fartforøgelse, man kan opnå. Øges f.eks. motoreffekten til 100%, fås sjældent mere end en fartforøgelse på 5%.Curve A of FIG. 1 thus shows a possible course, e.g. corresponding to 80% engine power, ie when the ship sails long distances. You rarely sail with more than 80% engine power, as this will essentially only result in increased wear and oil consumption that is not at all economical to the modest increase in speed that can be achieved. Increases e.g. engine power to 100%, rarely more than a 5% increase in speed.

På fig. 2 ses et principskema for et strømforsyningsanlæg 25 ifølge opfindelsen, hvor 1 angiver en trefaset synkrongenerator, der er koblet til skrueakslen, f.eks. via et mekanisk gear. Generatorens 1 trefasede udgangsspænding ledes til to strømforsyningsnet 6 og 7, der begge leverer trefaset vekselstrøm til forbrugere. Nettet 7 er direkte koblet 30 til generatorudgangen 2, medens nettet 6 kobles til generatorudgangen 2 gennem et styret ensretterkredsløb 3, der omsætter den trefasede spænding til en almindelig jævnspænding 4, som i et nyt omsætterkredsløb 5 omsættes til trefaset vekselspænding 6 med konstant frekvens og spænding. Om-35 sætterkredsløbet 5 kan være en elektronisk styret veksel- 5In FIG. 2 is a schematic diagram of a power supply system 25 according to the invention, wherein 1 indicates a three-phase synchronous generator coupled to the screw shaft, e.g. via a mechanical gear. The three-phase output voltage of the generator 1 is fed to two power supply networks 6 and 7, both supplying three-phase alternating current to consumers. The grid 7 is directly connected 30 to the generator output 2, while the grid 6 is connected to the generator output 2 through a controlled rectifier circuit 3, which converts the three-phase voltage to a common DC voltage 4, which in a new converter circuit 5 is converted to three-phase alternating voltage 6 with constant frequency and voltage. . The transducer circuit 5 may be an electronically controlled switch 5

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retter eller en vekselstrømsgenerator trukket af en jævnstrømsmotor, f.eks. et-ankeromformer eller et andet egnet DC/AC omformerkredsløb.dishes or an alternator drawn by a DC motor, e.g. one-anchor converter or other suitable DC / AC inverter circuit.

5 Nettet 7, der ikke har konstant frekvens eller spænding, men en frekvens, der afhænger af akselomdrejningstallet og en spænding, der er afhængig af belastningen, bruges til at forsyne alle de brugere, der kan acceptere en sådan forsyning af lavere kvalitet, f.eks. el-motorer, pumper, kom-10 pressorer, ventilationsanlæg, køleanlæg m.v. Anlæg der ofte er trukket af en asynkronmotor. Nettet 6 anvendes derimod til at forsyne de brugere, der kun kan acceptere en strømforsyning med fast frekvens og spænding, f.eks. navigations- og kommunikationsanlæg styremaskiner, belysning m.v.5 The grid 7, which has no constant frequency or voltage, but a frequency that depends on the shaft speed and a voltage dependent on the load, is used to supply all the users who can accept such a lower quality supply, f. eg. electric motors, pumps, compressors, ventilation systems, cooling systems, etc. Installations often pulled by an asynchronous motor. The grid 6, on the other hand, is used to supply those users who can only accept a fixed frequency and voltage power supply, e.g. navigation and communication systems control machines, lighting, etc.

15 På nettet 7 vil man have en frekvens, der korresponderer med skrueakslens omdrejningstal, altså en mekanisk bunden frekvens. Ved en given belastning vil spændingen således stige, hvis frekvensen øges, og spændingen vil falde, hvis 20 frekvensen sænkes. Man vil hermed opnå, at alle hjælpefunktionerne vil arbejde i samme takt som hovedmaskinen og derved automatisk kun optage den effekt, der er nødvendig, hvilket giver en stor effektbesparelse sammenlignet med eksisterende anlæg, hvor man forsøger at holde den samlede 25 strømforsyning på konstant spænding og konstant frekvens, således at hjælpefunktionerne vil optage den fulde effekt uanset motoromdrejningstallet.15 On the grid 7 one will have a frequency corresponding to the speed of the screw shaft, that is, a mechanically bound frequency. Thus, at a given load, the voltage will increase if the frequency is increased and the voltage will decrease if the frequency is lowered. This will ensure that all the auxiliary functions will work at the same rate as the main machine, thereby automatically absorbing only the power needed, which gives a great power saving compared to existing systems, where you try to keep the total 25 power supply at constant voltage and constant frequency, so that the auxiliary functions will record the full power regardless of the engine speed.

Et skibs elektriske effektbehov kan opdeles på følgende må-30 de: a 10% af den elektriske effekt anvendes til radio, kommunikation, navigation, belysning, styremaskine m.v. Dette udstyr behøver konstant spænding og konstant fre-35 kvens.The electrical power requirements of a ship can be divided into the following ways: a 10% of the electrical power is used for radio, communication, navigation, lighting, control machine, etc. This equipment needs constant voltage and constant frequency.

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6 b 50% elektrisk effekt anvendes til motordrift ved pumper, kompressorer, ventilationsanlæg, køleanlæg og lignende. Sådanne anlæg kan enten arbejde i længere perioder eller anvendes til formål, hvor man ikke behøver den fulde ka-5 pacitet, når hovedmotoren ikke udnyttes 100%, blot vari ationen af elforbruget (arbejdsbehovet) er ligefremt proportionalt med hovedmotorens omdrejningstal.6 b 50% electrical power is used for motor operation by pumps, compressors, ventilation systems, cooling systems and the like. Such systems can either operate for extended periods or be used for purposes where one does not need the full capacity when the main engine is not 100% utilized, simply where the ation of electricity consumption (the work demand) is exactly proportional to the speed of the main engine.

c 40% elektrisk effekt anvendes til opvarmning og mindre 10 vigtige elektromotorer, hvor den indkoblede tid er uden betydning, og derfor kan spænding og frekvens variere uden problemer, blot maskinen ikke beskadiges, idet den indkoblede periode kan varieres uden ulempe for skibets funktion, og som regel sker styringen af disse funk-15 tioner ved hjælp af termostater, pressostater eller ni- veaukontroludstyr.c 40% electrical power is used for heating and less 10 important electric motors where the switch-on time is of no importance, and therefore voltage and frequency can vary without problems, but the machine is not damaged, as the switch-in period can be varied without inconvenience to the ship's operation, and as a rule, these functions are controlled using thermostats, pressure switches or level control equipment.

Det er således kun en beskeden del af effektforbruget, der behøver at leveres med en bestemt og konstant frekvens og 20 spænding, og man behøver således kun at stabilisere en mindre del af den elektriske effekt, hvorfor kredsløbet 4 og 5 bliver væsentlig mindre omkostningskrævende end ved kendte anlæg, hvor man normalt stabiliserer hele spændingsforsyningen .Thus, only a modest part of the power consumption needs to be supplied with a certain and constant frequency and voltage, and thus only a minor part of the electrical power needs to be stabilized, and therefore the circuits 4 and 5 become considerably less costly than at well-known systems where the entire supply of power is usually stabilized.

2525

Et almindeligt akselgeneratorsystem kan desuden ikke anvendes under visse forhold, nemlig med stærk nedsat fart eller i kraftig søgang, hvor hovedmotorens omdrejningstal svinger mere end den tilladelige frekvensvariation. Under sådanne 30 forhold anvender man derfor hjælpeaggregaterne til elektricitetsproduktion med deraf følgende øget olieforbrug.In addition, a conventional shaft generator system cannot be used under certain conditions, namely at a greatly reduced speed or at high sea speed, where the main engine rpm fluctuates more than the allowable frequency variation. Under such conditions, therefore, the auxiliary power generators are used, with the resultant increased oil consumption.

Et anlæg ifølge opfindelsen kan derimod anvendes under alle forhold, blot spændingen eller frekvensen ikke afviger så 35 meget fra de nominelle værdier, at forbrugerne beskadiges.In contrast, a system according to the invention can be used in all conditions, provided that the voltage or frequency does not deviate so much from the nominal values that the consumers are damaged.

77

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Almindeligvis kan det sædvanlige elektriske udstyr tåle afvigelser på indtil plus 10% til minus 15% fra den nominelle spænding, uden at skader opstår. Overskrides disse tolerancer, kan hjælpefunktioner på skibet svigte eller beskadi-5 ges, hvorfor anlægget må være indrettet således, at der kobles over på strømforsynings-hjælpeaggregaterne på sædvanlig måde.In general, the usual electrical equipment can withstand deviations of up to plus 10% to minus 15% from the rated voltage without causing damage. If these tolerances are exceeded, the auxiliary functions of the ship may fail or be damaged, so the system must be arranged so that the power supply auxiliaries are switched in the usual way.

Claims

A method of supplying ships with at least one synchronous machine as a shaft generator and at least one auxiliary unit consisting of a self-powered motor with a generator providing substantially constant frequency electrical power, and coupling means for coupling the ship's rails for alternating power supply to either shaft generator supply or to the auxiliary power supply, and wherein the power from the shaft generator (s) is distributed to two supply grids, a first grid in which voltage and frequency follow the voltage and frequency of the shaft generator, and a second grid in which voltage and frequency are kept substantially constant, characterized by the first grid is supplied with about 85 15 - 95% of the power delivered from the shaft generator (s), the generator (s) being arranged such that at a given load a voltage increase occurs as the frequency increases and a decrease in voltage when the frequency is reduced and that the second grid is added ci about 5 - 15% of the 20 generator power.

Method according to claim 1, characterized in that the first supply network is used for power supply of electric motors, pumps, compressors, ventilation systems, cooling systems, etc. and the second supply network is used for power supply of navigation and communication systems, control machine, lighting similar installations requiring constant voltage and frequency.

3. Power supply systems for ships with at least one synchronous machine as a shaft generator (1) and with at least one auxiliary unit consisting of a self-contained motor with generator providing substantially constant frequency electrical power, and coupling means for connecting the ship's collector rails for AC power either the shaft generator supply or for the auxiliary power supply and for carrying out the method according to claim 1, wherein the plant comprises two separate supply grids (6,7), a first grid (7) directly receiving power from the shaft generator / generator 5. the sensors (1) and another grid (6), which also receive power from the shaft generator (s) (1), but via a circuit (3,4,5) which ensures substantially constant voltage and frequency on the grid, characterized in that the first mesh (7) is dimensioned and arranged to be fed approx. 85 - 95% of the generator power from the shaft generator, arranged such that at a given load there is a voltage increase as the frequency increases and a decrease in voltage as the frequency is reduced and the second grid (6) is dimensioned and arranged for to be applied approx. 5 - 15% 15 of the generator power.

Power supply system according to claim 3, characterized in that the first supply network (7) is connected to electric motors, pumps, compressors, ventilation systems, cooling systems, etc. and the second network (6) is connected to navigation and communication systems, control machines, lighting and similar equipment. that requires constant voltage and frequency.