The present invention relates to a system for ful- filling a power requirement in case of a sudden di f feren- tial power requirement state , such as in the event of an unexpected traf fic situation, power failure , defect and/or blackout , by a supply of electrical energy to a vessel or ship , preferably an inland vessel , further preferably an inland cargo ship, with an electric propulsion system . Fur- thermore , the present invention relates to a related meth- od .

It is known to provide a ship with an electric pro- pulsion system . Such electric propulsion system comprises several generators and a propulsion engine or a pair of propulsion engines . Sometimes sideway propulsion systems are provided as well . Such systems provide a large number of known advantages such as flexibility of electrical sys- terns in the ship . As a ship requires to be operable at all times by means of propulsion and rudder, it is a require- ment that at least two generators with at least two engines are actively providing power to the ship at all times . The present inventor came to the reali zation that this is inef- ficient as ships do not require the minimum power provided by such 2 engines at all times , such as to prevent colli- sions or to be able to react with steering of the ship in all kinds of situations . When sailing downstream of a river or in a water with no current or even a current flowing in the direction of the ship, the requirements of having to engines running at all times causes the use of fuels that is wasteful . In such situations , it would be inef ficient to provide batteries taking up the whole excess power of such fuels .

With this reali zation, the present inventor defined a goal of the present invention being that such fuel is to be saved while maintaining a safety level . To this end, the present invention relates to a system for ful filling a pow- er requirement in case of a sudden di f ferential power re- quirement state , such as in the event of an unexpected traf fic situation, power failure , defect and/or blackout , by a supply of electrical energy to a vessel or ship , pref- erably an inland vessel , further preferably an inland cargo ship, with an electric propulsion system, the system com- prising :

- at least one busbar for distributing electrical en- ergy between generation thereof and propulsion of the ship therewith,

- at least one busbar monitoring device for monitor- ing power parameters of the busbar,

- at least two gensets for the generation of the electrical energy to the at least one busbar, a genset com- prising a power station or an engine and a generator for generating electricity,

- at least one genset controller for controlling op- eration of the at least two gensets , wherein :

- all of the at least two gensets are configured to function in a power generating mode for the generation of the electrical energy,

- at least one of the gensets is configured for functioning in a standby operation mode , such as during op- eration of the ship wherein the power station or engine may be switched of f or operate in a low-power, such as low load mode of operation, and

- at least one of the at least one the genset con- troller is configured to receive an input signal signi fying the sudden di f ferential energy requirement state , to make a determination to trans fer a respective genset from the standby operation mode to the power generating mode and to control respective gensets functioning in the standby oper- ation mode to transition operation to ful fill the power re- quirement , and wherein :

- during the standby operation mode of the genset , the generator of the genset is configured to operate in a state of synchroni zation with the busbar, preferably pow- ered by power from the busbar .

It is an advantage of a system according to the pre- sent invention that because at least one of the gensets is configured to function in a standby operation mode , fuel is saved while such at least one genset is in the standby op- eration mode . In case a sudden di f ferential energy require- ment state arises , the respective genset may be trans ferred to its power generating mode in a very short timeframe based on receiving the input signal . The input signal may be based on a low frequency and/or voltage of the busbar as a busbar parameter . However alternatively, in case of fail- ure of another genset that is operating in power generating mode while another genset is in the standby operating mode , a signal from the genset functioning in power gener- ating mode indicating problems , imminent failure or upcom- ing failure , may be provided to the genset controller in order to trans fer the genset in the standby operating mode to the power generating mode even before busbar parameters are af fected by such failure of the other genset .

An advantage of such operating of the genset in a state of synchroni zation with the busbar is that the gener- ator is not required to be started up from for instance a standstill situation . Starting up a generator from a stand- still situation costs a lot of energy and it takes time to have a generator run at optimal operating parameters . Also , when the generator is running in synchroni zation with the busbar, such generator provides reactive power advantages to the busbar and thereto coupled generators and consumers .

According to a first preferred embodiment , the system provides timely power by the at least one genset configured for functioning in the standby operation mode for timely maneuverability of the vessel based on power , preferably ful filling a classi fication requirement of timely maneuver- ability of the vessel based on power provided by these gen- sets when trans ferred from the standby operation mode to the power generating mode . It is an advantage of such em- bodiment that the vessel is maneuverable on the basis of this provided power in such a fast manner, such as in time frames indicated below, that the vessel is always maneuver- able in timely manner to prevent a calamity, such as an ac- cident or collision, being taken by the current or running into shallow water . For such situations , it is preferred according to the present invention to ful fill requirements of at least one classi fication for a vessel to always have suf ficient power available within predetermined time frames .

According to a further preferred embodiment , the sud- den di f ferential power requirement state is defined as a state wherein a di f ference between a currently supplied electrical power and a required power supply is larger than the amount of power that can be provided by gensets that are currently in the power generating mode . When a large consumer is started up or when a current consumer is put under a heavy load, such as a digger that runs into a heavy obj ect in the bottom of the water, and the combination of the at least two gensets was not preemptively adapted to such rise in power requirement , the at least one genset configured to function in standby operation mode and run- ning in standby operation mode is able to quickly add power capacity to other running gensets . Thereby it is advanta- geously achieved that the power requirement is met during rise of the power demand by such influence of the rising power demand .

In an alternative manner, the sudden di f ferential power requirement state is defined as a state wherein bus- bar parameters are outside predefined operational or opera- tionally acceptable ranges . When this happens , such as when a voltage rises or lowers beyond operationally acceptable parameters or when a frequency that normally would be main- tained at substantially 50 Hz drops below such acceptable ranges , such as for example 47 Hz but any value may be used, a quick rise in supply will power is required and is preferred to prevent a blackout of the system as a whole .

In a further alternative manner, the sudden di f feren- tial power requirement state is defined as a blackout situ- ation of at least one of the at least one busbar . A black- out situation may happen when a single running genset fai ls or when power demand suddenly exceeds the available genset power . Other situations in which a blackout situation may happen can be caused by a short-circuit or failing of a power consumer connected to any of the at least one busbar . When that happens , it is vitally important that all af fect- ed systems are disconnected from the respective busbar and the system is powered up as soon as possible . The use of a genset configured to run at standby operating mode is pro- vided according to the embodiment to provide the fastest possible restart of the electrical system of the ship as a whole . In case of a blackout , it is important that essen- tial systems , such as navigational systems , are connected again first and optional systems are only connected when safety is achieved first .

In a further alternative manner, the sudden di f feren- tial power requirement state is defined as a power require- ment input based on a sudden propulsion requirement re- ceived from a navigation system or a propulsion system of the ship . It may happen that an unexpected change in speed and/or course of the vessel has to be provided at a moments notice . I f this happens , the power demand may be rising very steeply which may not be providable by a for instance single running genset . When this happens , a system accord- ing to the embodiment provides that a genset configured for functioning in a standby operating mode may be switched to its power generating mode very quickly to provide naviga- tional reactiveness within a speci fied acceptable time . An example thereof is that a ship that is sailing downstream at a low propulsion engine power may be reversed to maximum engine power, even when it was running on one relatively small genset while a relatively large genset configured for functioning in a standby operating mode actually was in the standby operating mode according to the present invention or an embodiment thereof to provide switching to power gen- erating mode in an acceptable small timeframe .

According to a further preferred embodiment , the ful- filling of the power requirement is time-critical within a time frame of the 0-20 seconds , preferably 0- 15 seconds , further preferably 0- 10 seconds , further preferably 1 - 8 seconds , further preferably 1 - 6 seconds , further preferably 1-5, 1 -4 , 1 -3 , 1 -2 seconds . It is an advantage of such im- plementation of time critical results , that it may be achieved that a vessel equipped with such an embodiment is certi fiable as a safe system while saving the fuel by al- lowing at least one of the gensets to be configured for standby operating mode .

According to a further preferred embodiment , ful- filling of the power requirement is based on a propulsion power requirement , preferably in addition with onboard electrical requirements . Such power requirement is related to the amount of power that is required to have the vessel function with a suitable combination of propulsion power and rudder operations that the ship may be steered and/or navigated safely . Further preferably, ful filling of the power requirement is based on rudder power requirements or rudder reactive power requirements .

A further preferred embodiment of the present inven- tion provides a system comprising a data store for storing power requirements in relation to ship control parameters , such as weather conditions , water current conditions , whether power requirements or rudder reactive power re- quirements , power parameters of the at least two gensets , power parameters of the at least one genset configured for functioning in standby operating mode . With such predeter- mined and prestored data, all kinds of combinations of pow- er that may be provided by a respective genset or combina- tion of gensets and power requirements by such conditions may be combined for a suitable outcome . In case a vessel goes from a relatively quiet weather environment with low currents to a relatively turbulent whether environment with signi ficant currents , a relatively light capacity genset may be switched of f in favor of a relatively high capacity genset , of course preferably both with the configuration to function in standby power mode .

Further preferably, the system comprises at least one breaker , preferably at least one breaker per genset drive motor and/or further busbar consumer . With the application of such breakers , all systems may be switched of f from the busbar during powering on of a genset from a sudden di f fer- ential power requirement state . This allows for controlled powering on of the whole ships system or keeping certain subsystems of the ship system disconnected from the busbar by not unbreaking or closing the breakers .

Further preferably, in the standby operating mode , the engine may be operated below 30% of nominal capacity, preferably below 20% of nominal capacity, further prefera- bly below 10% of nominal capacity, further preferably below 0% of nominal capacity, further preferably below minus 5% of normal capacity further preferably between minus 5% and minus 10% of nominal capacity . This allows for favorable fuel savings during standby operating mode , while keeping the engine in motion for faster start up then when the en- gine was stopped . It is furthermore provided that the en- gine is dragged along by the generator based on for in- stance busbar electrical power .

According to a further preferred embodiment , the sys- tem comprises a clutch between the power station or engine and the generator, the genset being configured to allow the coupling by the clutch in the standby operating mode . With such clutch, it is provided in an advantageous manner that the engine may be fully stopped for motion while the gener- ator is kept in rotation to be synchroni zed with the bus- bar .

In a further preferred embodiment , the system com- prises a flywheel wherein the flywheel is preferably cou- pled to the generator, preferably further comprising decou- pling means for decoupling of the flywheel from the genera- tor . It is an advantage of such a flywheel that even with- out busbar power the generator may be kept in rotation for a predetermined amount of time based on energy stored in the flywheel . For instance , in case of a full blackout of the electrical systems of the ship, a startup of the genset that was in standby operating mode may be performed faster with the application of this flywheel . According to a further preferred embodiment , the sys- tem comprises a heater assembly for heating of the engine while being switched of f or in low load mode . With this , the engine is easier to start up and will endure less wear and tear during standby operating mode , and/or during times of low fuel supply while being kept in rotation by the gen- erator as indicated in the above .

According to a further preferred embodiment , the sys- tem comprises venting means for venting of engine cylinders when the engine is operating at low rotations per minutes . An advantage thereof is that it requires less power to run the engine while little fuel is provided to the engine . Al- ternatively, the system comprises a pressuri zing assembly for pressuri zing engine cylinders to a preferred state and/or to prevent low-pressure in the cylinders .

According to a further preferred embodiment , the sys- tem comprises a system controller to adj ust power take-up to a power level providable by currently available genset capacity . In case a genset i s started up from standby oper- ation mode to power generating mode while not being able to sustain full power demand of the full ship system, only systems of the ship that are essential and ful fill the pow- er requirements of the available power from such genset will be started up .

A further aspect of the present invention relates to a method for ful filling a power requirement in case of a sudden di f ferential power requirement state , such as in the event of an unexpected traf fic situation, power failure , defect and/or blackout , by a supply of electrical energy to a vessel or ship , preferably an inland vessel , further preferably an inland cargo ship, with an electric propul- sion system, the system comprising :

- at least one busbar for distributing electrical en- ergy between generation thereof and propulsion of the ship therewith,

- at least one busbar monitoring device for monitor- ing power parameters of the busbar,

- at least two gensets for the generation of the electrical energy to the at least one busbar, a genset com- prising a power station or an engine and a generator for generating electricity,

- at least one genset controller for controlling op- eration of the at least one genset , wherein :

- all of the at least two gensets are configured to function in a power generating mode for the generation of the electrical energy,

- at least one of the gensets is configured for functioning in a standby operation mode , such as during op- eration of the ship wherein the power station or engine may be switched of f or operate in a low-power, such as low load mode of operation, and

- at least one of the at least one the genset con- troller is configured to receive an input signal signi fying the sudden di f ferential energy requirement state , to make a determination to trans fer a respective genset from the standby operation mode to the power generating mode and to control respective gensets functioning in the standby oper- ation mode to transition operation to ful fill the power re- quirement , the method comprising steps of :

- monitoring the busbar by the busbar monitoring de- vice ,

- operating at least one of the at least two gensets in the power generating mode according to current power re- quirements ,

- monitoring for an input signal by the at least one genset controller, - upon receipt of an input signal signi fying the sud- den di f ferential energy requirement state , such as from the busbar monitoring device , trans ferring a respective genset from the standby operating mode to the power generating mode and control the at least one genset to transition op- eration to ful fill the power requirement . Such method pro- vides advantages as indicated in the above in relation to the first aspect of the present invention . Furthermore , re- spective method steps are provided for application of each feature of the above aspect .

Further advantages , features and details of the pre- sent invention will be further elucidated on the basis of a description of one or more preferred embodiments with ref- erence to the accompanying figures . Similar yet not neces- sarily identical parts of di f ferent preferred embodiments may be indicated with the same reference numerals .

Fig . 1 provides a schematic representation of a first preferred embodiment according to the present invention .

Fig . 2 provides a schematic representation of a fur- ther preferred embodiment according to the present inven- tion .

Fig . 3 provides a further schematic representation of a further preferred embodiment according to the present in- vention .

Fig . 4 provides a schematic representation of ships embodied with a preferred embodiment according to the pre- sent invention .

Fig . 5 provides further embodiments according to the present invention .

Fig . 6 provides a further preferred embodiment ac- cording to the present invention .

A first preferred embodiment ( Fig . 1 ) according to the present invention relates to a power system, such as usable on a vessel or ship . It comprises two gensets 2 that are controlled by a genset controller 17 that is embodied as a process on a control computer 7 . In an alternative em- bodiment , the genset controller 7 may be embodied as a sep- arate control computer . The gensets each comprise a genera- tor 8 that is provided with motion energy by a motor 6 . The generator is provided with an optional flywheel 15 to store motion energy during operation of the genset . The flywheel 15 is optional as the system according to the present in- vention or certain preferred embodiments , is capable to function without a flywheel . Furthermore , the genset is provided with a clutch or clutching assembly 12 for cou- pling and decoupling the generator 8 from the engine 6 . Such decoupling is provided in a preferable standby opera- tion mode .

During the standby operation mode , it is preferred that the engine 6 is switched of f in order to prevent use of fuel . In case the engine is switched of f , it is pre- ferred according to a preferred embodiment , that the motor is heated from an external heating system in order to be maintained at a temperature at or somewhat below operating temperature of the engine or a cooling system thereof . This may provide a faster start time of the engine when the en- gine needs to be started to trans ferred the system from the standby operating mode to the power generating mode . It is preferred that the engine is maintained at any temperature between ambient temperature and operating temperature in order to achieve an improvement over maintaining the engine at ambient temperature .

Alternatively to switching of f of the engine , it is preferred to the engine 6 i s running at a low load such as below 30% of nominal capacity in order to save fuel . During such low load operation of the engine 6 , less fuel is pro- vided then required to operate the engine at or above 30% of nominal capacity . During such operation, the motor may be coupled with the generator in order to be driven or forced into motion by the generator . When the generator is driving the engine , less fuel is required to run the en- gine . Also during low load operation of the engine , the en- gine may be heated from an external heat source to raise temperature above the temperature achieved by the low fuel input .

In the embodiment of Fig . 1 , both generator sets are configured to be able to run in both a power generating mode and a standby operating mode . According to the present invention, also an embodiment in which only one of the two generator sets is configured to also run in the standby op- erating mode is considered . With the embodiment of Fig . 1 , both gensets may be used for continuous propulsion with the other one on standby . In case only one of the two generator sets is configured to also run in the standby operating mode , it is required that the thus configured generator set is to be the one that may be on standby while the other generator set that can only run in power generating mode is to be continuously operated for propulsion of the vessel .

A genset is configured for functioning in a standby operating mode , when the genset controller is able to con- trol the use of fuel below 30% of nominal capacity, to con- trol a clutch to decouple the generator 8 from the engine 6, to control the generator to operate in a state of syn- chroni zation with the busbar and/or to control that the generator is provided with power, preferably from the bus- bar, to operate in the state of synchroni zation with the busbar . The power for operating of the generator in syn- chroni zation with the busbar may also be provided in an al- ternative manner , such as by means of an auxiliary engine with drive means coupled to the generator .

A busbar 3 is provided between the generators and consumers , in this embodiment indicated as propulsion en- gines 16 , 16 ' , 16" such as of a vessel or ship . Alterna- tively, not shown, the busbar provides energy to all elec- tric systems of a vessel . Several busbars may be provided throughout the ship separated by power converters . In that way, distinct systems of the ship to be provided with elec- tric energy with distinct power parameters or respective busbar parameters . Operation of the propulsion engines 16 may be performed by a propulsion controller that is a dis- tinct control computer or such as in the embodiment of Fig . 1 embodied as a process performed by and/or controlled by the computer 7 .

In Fig . 2 , a variant is shown in which only the gen- set that is configured for functioning in a standby operat- ing mode is shown while another genset that may only oper- ate in power generating mode is omitted for simplicity . The busbar 3 connects the genset or gensets with the propulsion engines 16 , 16 ' . In this embodiment , the genset has a sepa- rate control computer 14 whereas the propulsion engines al- so have a dedicated controller 14 ' respectively 14" . The central control computer 7 is provided to control overall operation of the ship thereby controlling the respective controllers 14 , 14 ' , 14" . The system also comprises a bus- bar monitoring device 28 that monitors power parameters of the busbar and provides information of the power parameters to any computer 7 or controller 14 on the ship . The infor- mation monitoring may be performed continuously or only in case of a deviation from desired parameter values such as beyond a predetermined threshold of any parameter . In case the voltage drops below a certain value , this may mean that additional power is to be supplied to the busbar according to the present invention by switching a genset that is con- figured for functioning in a standby operation mode and that is operating in such standby operating mode , to a pow- er generating mode . Another example of a busbar parameter value is the frequency of the AC current on the busbar . In case of frequency drops below a predetermined threshold, such as below 47 Hz when 50 Hz is the operating frequency, a standby genset may be started up .

It is preferred that systems or subsystems , such as the generator set , a heater thereof , a propulsion engine or any other electric system of the ship is connected to the busbar or at least one busbar by means of a breaker 22 , 24 , 26 or 26 ' . The advantage or purpose thereof is that such devices or subsystems of the ship may be protected in case of a set electrical emergency and/or such that such devices of subsystems may be kept switched of f from the busbar in case of available power to the busbar is too low or limited to provide all subsystems with energy .

The genset that is to operate as a genset configured for functioning in a standby mode , is to be able to provide suf ficient power for the propulsion engines and for operat- ing the rudder in order to steer or navigate the ship . This is also relevant for ful filling requirements of a classi fi- cation of a ship or vessel .

Alternative considerations for the amount of power a genset that is to operate as a genset configured for func- tioning in a standby mode , is to be able to provide suf fi- cient power for a power demand of subsystems of the vessel that are deemed important or that are currently used for and operating function of the vessel . An example thereof is a vessel with a cooling system is required to have power provided to the cooling system . A further example thereof is a vessel with a dredging system requires the dredging system to function even when unexpected high loads are en- countered during a dredging operation, as exempli fied in the above .

An example of states and steps to be performed in or by a system according to the present invention or in embod- iments thereof is as follows . During regular operation of the vessel , a part of the available generator sets is providing power to systems of the ship . An example is when a ship is sailing downstream a river, a low amount of pro- pulsion power is required to navigate the ship . I f the cur- rently running generator set has a failure , the engine of that generator set may stop and power to the busbar stops . In such situation, that may be named a blackout , the busbar is to be started up again . In this case , preferably all breakers are disconnected, the genset that is configured for functioning in a standby operation mode and that is functioning in the standby operation mode is provided with a signal to switch to power generating mode .

In such situation, the generator 8 of the genset is already rotating at suitable busbar parameters , such as frequency . This means that the generator does not have to be started up from a standstill provide power to the bus- bar , but only the engine needs to be started up to contin- ued the motion of the generator . Starting up of the engine requires little time , especially when the engine is kept in operating condition, such as having a suitable temperature , or already being in motion running at low load with low fuel , such as being drawn by the generator or kept into mo- tion by a secondary engine . Thus , advantageously the engine 6 of the genset is started from the standby condition up and coupled with the generator and the generator is start- ing to provide power to the busbar for the purpose of which the breaker is closed to provide the power to the busbar . With this , the operation of the engine 6 and the generator 8 are closely monitored by the controller 14 in order to provide power to the busbar with right parameters relating to frequency and voltage .

Subsequently, respective breakers to a propulsion en- gines 16 and a steering engine 16 ' for a steering propeller are closed to provide these with power from the busbar in order to navigate or steer the ship .

In Fig . 4 , a ship is shown with variations of embodi- ments according to the present invention . The embodiment is provided with a central control computer 7 and a front gen- erator set to and a read generator set to similar to the generator sets of Fig . 1 . To the rear, a main propeller is provided for propulsion of the ship . To the front of the main propel ler, a steering propeller is provided for steer- ing the ship . At the front of the ship, also a steering propeller are provided . Thus , it is shown that a ship may be provided with propulsion and steering by the combination of two gensets , of which one genset during regular sailing is not required to have fuel consumption the saving energy for the ship to operate .

In Fig . 5 , variations with two or four gensets 2 are provided on a ship with two drive propellers and four steering propellers . In Fig . 6 , a relatively large ship is shown with 7 gensets , two drive propellers and four steer- ing propellers . Depending on sailing conditions or other operating conditions or power requirements of further sub- systems present in the vessel , one or more of the gensets may be operated continuously in the power generating mode and one or more genset that are configured for functioning in a standby operating mode may be operated in a standby operating mode depending on emergency power requirements and/or expected changes in power requirements when operat- ing the vessel .

The engine running at low capacity may comprise run- ning on low fuel . The engine running at negative capacity is preferably intended to mean that the engine is pulled by the generator coupled to the engine , preferably wherein the generator is provided with energy from the at least one busbar .

The present invention is described in the foregoing on the basis of preferred embodiments . Di f ferent aspects of di f ferent embodiments are expressly considered disclosed in combination with each other and in all combinations that on the basis of this document , when read by a skilled person of the area of skill , fall within the scope of the inven- tion or are deemed to be read with the disclosure of this document . These preferred embodiments are not limitative for the scope of protection of this document . The rights sought are defined in the appended claims .