EP4725094A1

EP4725094A1 - Electrical apparatus for connecting an electrical load of a ship to at least one fuel cell

Info

Publication number: EP4725094A1
Application number: EP24738056.1A
Authority: EP
Inventors: Andrea PIETRA
Original assignee: Fincantieri SpA
Current assignee: Fincantieri SpA
Priority date: 2023-06-09
Filing date: 2024-06-07
Publication date: 2026-04-15
Also published as: CN121399816A; WO2024252350A1; KR20260017383A

Abstract

An electrical apparatus (100) for connecting an electrical load (L) of a ship to at least one fuel cell (10), the electrical apparatus (100) comprising : at least one electricity storage unit (20) configured to be connected to said at least one fuel cell (10) in a respective electric node (N1), said at least one electricity storage unit (20) comprising a plurality of super-capacitors (30) connected to the electric node (N1), the at least one fuel cell (10) being adapted to charge, during a step of initializing the apparatus (100), the plurality of super- capacitors (30) of the at least one electricity storage unit (20); an electric power converter (40) of the DC/AC type operatively connected between the electric node (N1) for the connection of the at least one fuel cell (10) with the at least one electricity storage unit (20) and the electrical load (L), the converter (40) comprising a plurality of input capacitors arranged on the DC side of the converter (40), said converter (40) being configured to receive a direct electric current as input and to supply the electrical load (L) with a respective alternating electrical voltage; an electric pre-charge module (50) arranged between the electric node (Nl) for the connection of the at least one fuel cell (10) with the at least one electricity storage unit (20) and the converter (40). The electrical pre-charge module (50) is configured to pre-charge, during the initialization step of the apparatus (100), the plurality of input capacitors arranged on the DC side of the converter (40). The at least one electricity storage unit (20) is configured to electrically discharge, at least partially, the plurality of super-capacitors (30) in the case of an instantaneous variation of the electrical load (L), and to supply the electrical load (L) with the corresponding instantaneous variation of electric power required by the electrical load (L) to the at least one fuel cell (10).

Description

"Electrical apparatus for connecting an electrical load of a ship to at least one fuel cell" DESCRIPTION

[ 0001 ] Field of the invention

[ 0002 ] The present invention relates to the naval industry, in particular to an electrical apparatus for connecting an electrical load of a ship to at least one fuel cell .

[ 0003 ] Technological background

[ 0004 ] Nowadays , the environmental impact of a ship , especially i f large , such as a cruise ship, is an essential aspect which is no longer negligible and therefore kept well in mind by builders and shipowners . [ 0005 ] For this reason, the naval industry is constantly searching for alternative technologies for producing electricity on board ships which reduce the environmental impact of a ship .

[ 0006 ] The refore , the need is strongly felt to also integrate an alternative technology with a low environmental impact into an electric power supply network of a ship, such as a fuel cell generator, which can be used to power an electrical load of the ship and thus reduce the environmental impact of the ship as much as possible .

[ 0007 ] Summary [ 0008 ] It is the obj ect of the present invention to devise and provide an electrical apparatus for connecting an electrical load of a ship to at least one fuel cell so as to power such an electrical load, as an alternative to the conventional electric power supply network of the ship, thus allowing the environmental impact of the ship to be reduced as much as possible .

[ 0009 ] Such an obj ect is achieved by an electrical apparatus according to claim 1 .

[ 0010 ] The present invention is also directed to a related method for connecting an electrical load of a ship to at least one fuel cell .

[ 0011 ] The present invention also relates to an electric power supply system for an electrical load of a ship comprising said electrical apparatus and a ship comprising such an electric power supply system.

[ 0012 ] Brief description of the Figures

[ 0013 ] Further features and advantages of the electrical apparatus , the related method and system according to the invention will become apparent from the following description of preferred embodiments , given by way of nonlimiting indication, with reference to the accompanying drawings , in which :

[ 0014 ] - Figure 1 diagrammatically shows an example of a ship in which an electrical system and the related method for supplying electric power to a load electrically connected to the electric power supply network of a ship are usable, in accordance with the present invention; [ 0015 ] - Figure 2 diagrammatically shows an electrical system for the electric power supply of an electrical load of a ship, in accordance with the present invention, and [ 0016 ] - Figure 3 shows , by means of a block diagram, a method for connecting an electrical load of a ship to at least one fuel cell , in accordance with the present invention .

[ 0017 ] Detailed description

[0018 ] With reference to the aforesaid Figures , 100 indicates as a whole an electrical apparatus for connecting an electrical load L of a ship 1 to at least one fuel cell 10 .

[ 0019 ] The electrical load L of the ship 1 i s representative of a single shipboard user or of an electrical "power" distribution system, possibly including a propulsion system of a ship with electric propulsion, or a shipboard light .

[ 0020 ] An example of a ship, indicated by reference numeral 1 as a whole , is shown in Figure 1 .

[0021 ] For the purpose of the present description, ship means any vessel usable for cruises , recreational and tourist service , e . g . , a cruise ship, as shown in Figure 1 , or any other ship, e . g . , such as ships usable in the military industry, merchant ships , work ships , etc .

[0022 ] The electrical load L and the at least one fuel cell 10 are diagrammatically shown in Figure 2 .

[0023] The at least one fuel cell 10 is installable on board the ship and is usable as an electric power supply generator, with reduced environmental impact , for the load L, as an alternative to the electric power supply ensured by an on-board electric power supply network with which the ship 1 is provided .

[0024 ] The at least one fuel cell 10 is any fuel cell without technological limitations .

[0025 ] For example , the at least one fuel cell 10 is of the Low Temperature Proton Exchange Membrane (LTPEMFC ) type .

[0026] The on-board electric power supply network is diagrammatically shown in Figure 2 with reference numeral 200 .

[0027 ] The at least one fuel cell 10 is adapted to provide a direct electric current to at least one electricity storage unit 20 , described below .

[0028 ] The direct electric current supplied by the at least one fuel cell depends on the number of fuel cells actually installed and the electrical connection thereof .

[0029] By way of example, the direct electric current supplied by the at least one fuel cell can be equal to about 240A.

[0030 ] The direct electric current corresponds to an electrical voltage dispensed by the at least one fuel cell . [0031 ] The electrical voltage dispensed by the at least one fuel cell depends on the number of fuel cells actually installed and the electrical connection thereof .

[0032 ] By way of example, the electrical voltage dispensed by the at least one fuel cell can be equal to about 412 nominal Volts .

[0033] The on-board electric power supply network 200 is adapted to provide an alternating electric current, for example equal to 130A, corresponding to a respective electrical voltage, for example a three-phase voltage, with a value equal to 440V and a frequency equal to 60Hz .

[0034 ] With reference to Figure 2 , the electrical apparatus 100 comprises at least one electricity storage unit 20 configured to be connected to said at least one fuel cell 10 in a respective electric node N1 .

[0035 ] The at least one electricity storage unit 20 comprising a plurality of super-capacitors 30 connected to the electric node N1 .

[0036] In greater detail , the at least one electricity storage unit 20 is configured to be connected, by means of the electric node Nl , to the at least one fuel cell so that the plurality of super-capacitors 30 are arranged between the +/- output polarities of the at least one fuel cell 10 .

[0037 ] By way of example , the plurality of supercapacitors 30 comprises 130F super-capacitors arranged in series and in a number such as to obtain a set overall electricity storage capacity .

[0038 ] The at least one fuel cell 10 , during a step of initializing the apparatus 100 , is adapted to load the plurality of super-capacitors 30 of the at least one electricity storage unit 20 .

[0039] The apparatus 100 further comprises an electric power converter 40 ( inverter ) of the DC/AC type, hereinafter also simply converter 40 , operatively connected between the electric node N1 for the connection of the at least one fuel cell 10 with the at least one electricity storage unit 20 and the electrical load L .

[0040 ] In accordance with the present invention, as clearly shown in Figure 2 and also described below, the electric power converter 40 of the DC/AC type is configured to allow the electric node N1 for the connection of the at least one fuel cell 10 with the at least one electricity storage unit 20 and the electrical load L to be connectable directly to the at least one fuel cell 10 , i . e . , without the need to interpose further DC/DC conversion/stabili zation stages between the at least one fuel cell 10 and the converter 40 of the apparatus 100 .

[0041 ] Therefore , in accordance with the present invention, the at least one electricity storage unit 20 is directly connectable, by means of the electric node Nl , to the at least one fuel cell 10 so that the plurality of super-capacitors 30 are directly arranged between the + /- output polarities of the at least one fuel cell 10 .

[0042 ] In this respect , the converter 40 is in fact configured so as not to require , on the DC side of the converter 40 , a stable and constant DC electrical voltage as input .

[0043] In fact, the converter 40 is configured to provide , on the DC side of the converter 40 , a minimum electrical ignition voltage value on the DC side corresponding to a minimum electrical voltage value to be dispensed by the at least one fuel cell 10 , and to ensure, on the AC side of the converter 40 , stability of electrical quantities ( electrical voltage and frequency) up to a maximum electrical voltage value to be dispensed by the at least one fuel cell 10 .

[0044 ] In greater detail , the converter 40 (DC/AC inverter) is configured to generate a three-phase electrical output voltage at constant frequency with an ef fective value which is in turn constant and equal to the one corresponding to that obtained by converting the minimum DC electrical voltage to be dispensed by the at least one fuel cell 10 into AC .

[0045 ] Moreover, the components of the converter 40 (DC/AC inverter) are sized to withstand a DC electrical input voltage up to the maximum electrical voltage to be dispensed by the at least one fuel cell 10 ( fuel cell ) .

[0046] The electrical isolation transformer 85, described below with reference to an embodiment , arranged directly downstream of the electric power converter 40 ( inverter ) of the DC/AC type , in addition to ensuring galvanic isolation, has the task of adapting the electrical voltage generated by the converter 40 ( inverter) to the electrical voltage of the downstream electrical distribution network . [0047 ] By way of example, the converter 40 is configured to operate correctly by receiving as input electrical voltage values to be dispensed by at least one fuel cell 10 included in a very wide range of values and of the order of hundreds of Volts , for example 300 - 620 Vdc .

[0048 ] Back to the present invention, the converter 40 comprises a plurality of input capacitors arranged on the DC side of the converter 40 .

[0049] The converter 40 is configured to receive a direct electric current as input and to supply the electrical load L with a respective alternating electrical voltage . [0050 ] The electrical apparatus 100 comprises an electrical pre-charge module 50 arranged between the electric node N1 for the connection of the at least one fuel cell 10 with the at least one electricity storage unit 20 and the converter 40 .

[0051 ] The electrical pre-charge module 50 is configured to pre-charge, during the initialization step of the apparatus 100 , the plurality of input capacitors arranged on the DC side of the converter 40 .

[0052 ] This pre-charging of the plurality of input capacitors arranged on the DC side of the converter advantageously ensures an electrical input voltage which is as stable as possible, limiting the fluctuations in electrical voltage as input to the converter 40 during the operation thereof .

[0053] The at least one electricity storage unit 20 is advantageously configured to electrically discharge, at least partially, the plurality of super-capacitors 30 in the case of an instantaneous ( i . e . , " step" ) variation of the electrical load L and to supply the electrical load L with the corresponding instantaneous variation of electric power required by the electrical load L to the at least one fuel cell 10 .

[0054 ] The apparatus 100 is thus capable of powering the varied electrical load L . [0055 ] Such an instantaneous or sudden variation

(precisely, "step" variation) of the electrical load L can occur, for example, in the case of switching on the electrical load L or starting one or more electric motors , to be thus understood as electrical loads L .

[0056] The apparatus 100 is thus capable of advantageously ensuring power continuity and stability to the electrical load L and of compensating the inertia of the dynamic response of the at least one fuel cell 10 .

[0057 ] Therefore , the plurality of super-capacitors 30 has an active role in the operation of the apparatus 100 in cases of an instantaneous ("step" ) variation of the electrical load L .

[0058 ] In fact , the plurality of super-capacitors 30 , by electrically discharging, is able to dispense the instantaneous variation in electric power required by the electrical load L to at least one fuel cell 10 .

[0059] On the contrary, without the contribution of the plurality of super-capacitors 30 , such an instantaneous variation in electric power would be completely dependent on the fuel cell 10 alone which, due to a greater inertia in the response, would not be able to dispense it instantly .

[0060 ] In accordance with an embodiment, shown in Figure

2 , the at least one electricity storage unit 20 further comprises a resistor 60 arranged in series with the plurality of super-capacitors 30 between the electric node N1 and the plurality of super-capacitors 30 .

[0061 ] In this embodiment , shown in Figure 2 , the at least one electricity storage unit 20 comprises a diode 61 connected at the ends of the resistor 60 .

[0062 ] The resistor 60 is configured to limit the electric current absorbed by the plurality of super-capacitors 30 during a respective charging step .

[0063] The diode 61 is configured to allow the passage of the electric current dispensed by the plurality of supercapacitors 30 , during the respective discharging step, to supply the electrical load L with the corresponding instantaneous variation of electric power, described above, required by the electrical load L to the at least one fuel cell 10 .

[0064 ] Therefore , upon starting the apparatus 100 , the plurality of super-capacitors 30 of the at least one energy storage unit 20 , if discharged, are charged by the at least one fuel cell by means of the resistor 60 .

[0065 ] Similarly, whenever the plurality of supercapacitors 30 of the at least one energy storage unit 20 are partially discharged during the operation of the apparatus 100 , the plurality of super-capacitors 30 of the at least one energy storage unit 20 are recharged by the at least one fuel cell 10 by means of the resistor 60 .

[0066] It is thus advantageously possible to keep the at least one energy storage unit 20 always charged and ready to dispense power .

[0067 ] Therefore , it is reiterated that the plurality of super-capacitors 30 has an active role in the operation of the apparatus 100 in cases of an instantaneous ("step" ) variation of the electrical load L .

[0068 ] In fact , the plurality of super-capacitors 30 , by electrically discharging, is able to dispense the instantaneous variation in electric power required by the electrical load L to at least one fuel cell 10 .

[0069] On the contrary, without the contribution of the plurality of super-capacitors 30 , such an instantaneous variation in electric power would be completely dependent on the fuel cell 10 alone which, due to a greater inertia in the response, would not be able to dispense it instantly .

[0070 ] In accordance with an embodiment, in combination with any of the preceding ones , the electric power converter 40 of the DC/AC type comprises a three-phase inverter configured to convert the direct electric current received as input into the respective alternating electrical voltage .

[0071 ] In an embodiment , in combination with any of the preceding ones , the alternating electrical voltage output from the converter 40 is adjusted by pulse width modulation ( PWM) control .

[0072 ] In one embodiment, shown in Figure 2 , in accordance with any one of those described above, the electrical apparatus 100 further comprises a first switch 70 .

[0073] In this embodiment , shown in Figure 2 , the electrical apparatus 100 further comprises an electrical isolation transformer 85 arranged directly downstream of the electric power converter 40 of the DC/AC type .

[0074 ] In this respect, it is reiterated that the electrical isolation transformer 85, arranged directly downstream of the electric power converter 40 ( inverter ) of the DC/AC type , in addition to ensuring galvanic isolation, has the task of adapting the electrical voltage generated by the converter 40 ( inverter) to the electrical voltage of the downstream electrical distribution network . [0075 ] The first switch 70 comprises :

[0076] - a first input terminal T1 operatively connected by means of the electrical isolation transformer 85 to the electric power converter 40 of the DC/AC type to receive the alternating electrical voltage ;

[0077 ] - a second input terminal T2 operatively connectable to an on-board electric power supply network 200 of the ship 1 to receive a further alternating electrical voltage supplied by the on-board electric power supply network 200 of the ship 1 ;

[0078 ] - an output terminal T-U operatively connectable to the electrical load L;

[0079] - a first switching block Cl automatically operable to connect the output terminal T-U of the first switch 70 to the first input terminal T1 of the first switch 70 ;

[0080 ] a second switching block C2 automatically operable to connect the output terminal T-U of the first switch 70 to the second input terminal T2 of the first switch 70 .

[0081 ] The first switch 70 further comprises a logic control unit advantageously configured to automatically operate the first switching block Cl and the second switching block C2 without interrupting the power supply of the electrical load L between a first configuration of the electrical apparatus 100 adapted to supply the electrical load L with the alternating electrical voltage supplied by the converter 40 to power the electrical load L by means of the at least one fuel cell 10 and a second operating configuration of the electrical apparatus 100 adapted to supply the electrical load L with a further alternating electrical voltage to power the electrical load L by means of the on-board electric power supply network 200 of the ship 1 , if the alternating electric power supply voltage from the at least one fuel cell 10 through the converter 40 is not available .

[0082 ] In an embodiment, in combination with the preceding one, the logic control unit is configured to switch, take and maintain the first operating configuration of the electrical apparatus 100 during normal operation of the at least one fuel cell 10 and the electrical apparatus 100 .

[0083] In an embodiment, in combination with any of the preceding ones , in which the first switch 70 is provided, the logic control unit of the first switch 70 is advantageously configured to switch, take and maintain the second operating configuration if a malfunctioning condition of at least one of the at least one fuel cell 10 and the electrical apparatus 100 occurs .

[0084 ] Examples , provided without limitation, of malfunctioning conditions of at least one of the at least one fuel cell 10 and the electrical apparatus 100 are : [0085 ] -the direct electrical voltage supplied by the electric power converter 40 of the DC/AC type is outside a range of reference values ;

[0086] - the electric power converter 40 of the DC/AC type is overloaded;

[0087 ] - the at least one fuel cell 10 is turned of f .

[0088 ] In accordance with a further embodiment , shown in Figure 2 and in combination with any of those described above, in which the first switch 70 is provided, the electrical apparatus 100 further advantageously comprises a second switch 80 manually operable without interrupting the power supply of the electrical load L to connect the electrical load L to the on-board electric power supply network 200 of the ship 1 by means of a bypass electric power supply connection B-P excluding the connection of the output terminal T-U of the first switch 70 with the electrical load L, if the electric power converter 40 of the DC/AC type is put out of service , for example for maintenance following a fault .

[0089] In accordance with an embodiment , not shown in the Figures and in combination with any of those described above, the electrical apparatus 100 comprises a data processing unit and a user interface operatively connected to the data processing unit .

[0090 ] In this embodiment, the data processing unit is configured to provide , by means of the user interface, a plurality of information representative of an operating condition of the electrical apparatus 100 .

[0091 ] Examples , provided without limitation, of information representative of the operating condition of the electrical apparatus 100 are :

[0092 ] - information representative of a malfunctioning condition of an electric power converter 40 of the DC/AC type ;

[0093] - information representative of a condition of an electric power converter 40 of the DC/AC type in use ;

[0094 ] - information representative of a condition of an electric power converter 40 of the DC/AC type synchroni zed with a bypass electric power supply connection;

[0095 ] - information representative of an availability of a bypass electric power supply connection;

[0096] - information representative of a condition of bypass electric power supply connection in use ;

[0097 ] - information representative of a state of one or more automatic protection switches 90 ;

[0098 ] - information representative of a manual bypass electric power supply connection mode in use .

[0099] In accordance with an embodiment , not shown in the Figures and in combination with the preceding one, the data processing unit of the electrical apparatus 100 is configured to determine and provide , by means of the user interface , a plurality of information representative of electrical parameters of the electrical apparatus 100 .

[0100 ] Examples , provided without limitation, of information representative of electrical parameters of the electrical apparatus 100 are :

[0101 ] information representative of an electrical voltage as input to the electric power converter 40 of the DC /AC type ;

[0102 ] information representative of an operating frequency of the on-board electric power supply network 200 ;

[0103] - information representative of an electrical voltage of the on-board electric power supply network 200 ; [0104 ] - information representative of a continuous electrical output power of the electrical apparatus 100 ;

[0105 ] - information representative of an operating output frequency of the electrical apparatus 100 ;

[0106] - information representative of a continuous electrical output voltage of the electrical apparatus 100 . [0107 ] In accordance with an embodiment, shown in Figure 2 and in combination with any of the preceding ones , the electrical apparatus 100 further comprises a plurality of automatic switches 90 for protecting the input and output electric power supply connections of the electrical apparatus 100 .

[ 0108 ] Now also referring to the block diagram in Figure 3 , a method 300 for connecting an electrical load L to at least one fuel cell 10 is now described, hereinafter also simply connection method or only method, in accordance with the present invention .

[ 0109 ] It should be noted that the components and information mentioned below with the description of the method have already been described above with reference to the apparatus 100 and therefore will not be repeated for brevity .

[ 0110 ] The method 300 comprises a symbolic step of starting ST .

[0111 ] The method 300 comprises a step of providing 301 at least one electricity storage unit 20 configured to be connected to said at least one fuel cell 10 in a respective electric node N1 .

[0112 ] The at least one electricity storage unit 20 comprises a plurality of super-capacitors 30 connected to the electric node N1 .

[0113] The method 300 further comprises a step of providing 302 an electric power converter 40 of the DC/AC type operatively connected between the electric node N1 for the connection of the at least one fuel cell 10 with the at least one electricity storage unit 20 and the electrical load L .

[0114 ] The converter 40 comprises a plurality of input capacitors arranged on the DC side of the converter 40 .

[0115 ] The converter 40 is configured to receive a direct electric current as input and to supply the electrical load L with a respective alternating electrical voltage .

[0116] The method 300 comprises a step of charging 303 , by the at least one fuel cell 10 , during a step of initializing the apparatus 100 , the plurality of supercapacitors 30 of the at least one electricity storage unit 20 .

[0117 ] The method 300 further comprises a step of precharging 304 , by an electric pre-charge module 50 arranged between the electric node N1 for the connection of the at least one fuel cell 10 with the at least one electricity storage unit 20 and the converter 40 , during the step of initializing the apparatus 100 , the plurality of input capacitors arranged on the DC side of the converter 40 .

[0118 ] The method 300 further includes steps of , in the case of an instantaneous variation of the electrical load L, electrically discharging 305 at least partially the plurality of super-capacitors 30 and supplying 306 to the electrical load L, by the at least one unit of electrical energy storage 20 , the corresponding instantaneous change in electric power required by the electrical load L to the at least one fuel cell 10 .

[0119] Such an instantaneous or sudden variation of the electrical load L has been defined above .

[0120 ] The apparatus 100 is thus capable of powering the varied electrical load L .

[0121 ] The method 300 thus allows advantageously ensuring power continuity and stability to the electrical load L and to compensate the inertia of the dynamic response of the at least one fuel cell 10 .

[0122 ] It is reiterated that the use of the plurality of super-capacitors 30 has an active role in the operation of the apparatus 100 in cases of an instantaneous ("step" ) variation of the electrical load L .

[0123] In fact , the plurality of super-capacitors 30 , by electrically discharging, is able to dispense the instantaneous variation in electric power required by the electrical load L to at least one fuel cell 10 .

[0124 ] On the contrary, without the contribution of the plurality of super-capacitors 30 , such an instantaneous variation in electric power would be completely dependent on the fuel cell 10 alone which, due to a greater inertia in the response, would not be able to dispense it instantly .

[ 0125 ] The method 300 thus comprises a symbolic step of ending ED .

[ 0126 ] Other steps of the method, according to dif ferent embodiments , correspond to dif ferent functions of the electrical apparatus 100 described above in accordance with di fferent embodiments of the electrical apparatus 100 .

[0127 ] As mentioned above , the present invention also relates to a system 400 for powering an electrical load L of a ship 1 , hereinafter also simply connection system or simply system.

[0128] The system 400 comprises an on-board electric power supply network 200, already described above.

[0129] The system 400 comprises at least one fuel cell 10, already described above.

[0130] The system 400 further comprises an electrical apparatus 100 in accordance with the present invention, according to any of the embodiments described above.

[0131] As mentioned above, the present invention also relates to a ship 1 comprising a system 400 for the electric power supply of an electrical load L of the ship 1, described above.

[0132] With reference to Figure 2, an example of operation of the electrical apparatus 100 in accordance with the present invention is now described.

[0133] The electrical apparatus 100 connects an electrical load L of a ship 1 to at least one fuel cell 10.

[0134] At 1 east one electricity storage unit 20 of the apparatus 100 is connected in parallel to said at least one fuel cell 10 in a respective electric node N1.

[0135] The at least one electricity storage unit 20 comprises a plurality of super-capacitors 30 connected to the electric node N1.

[0136] The at least one fuel cell 10 charges, during a step of initializing the apparatus 100 , the plurality of super-capacitors 30 of the at least one electricity storage unit 20 .

[ 0137 ] An electric power converter 40 of the DC/AC type of the electrical apparatus 100 is operatively connected between the electric node N1 for the connection of the at least one fuel cell 10 with the at least one electricity storage unit 20 and the electrical load L of the ship 1 .

[0138 ] The converter 40 comprises a plurality of input capacitors arranged on the DC side of the converter 40 .

[ 0139 ] The converter 40 receives a direct electric current as input and supplies the electrical load L with a respective alternating electrical voltage .

[ 0140 ] An electrical pre-charge module 50 arranged between the electric node N1 for the connection of the at least one fuel cell 10 with the at least one electricity storage unit 20 and the converter 40 .

[0141 ] The electrical pre-charge module 50 pre-charges , during an initialization step of the apparatus 100 , the plurality of input capacitors arranged on the DC side of the converter 40 .

[ 0142 ] In the case of an instantaneous variation of the electrical load L, the at least one electricity storage unit 20 electrically discharges , at least partially, the plurality of super-capacitors 30 and supplies the electrical load L with the corresponding instantaneous variation of electric power required by the electrical load L to the at least one fuel cell 10 .

[ 0143 ] The apparatus 100 is thus capable of powering the varied electrical load L .

[0144 ] Therefore , power continuity and stability to the electrical load L and compensation of the inertia of the dynamic response of the at least one fuel cell 10 are advantageously ensured .

[0145 ] In fact , the plurality of super-capacitors 30 , by electrically discharging, manages to dispense the instantaneous variation in electric power required by the electrical load L to at least one fuel cell 10 .

[0146] On the contrary, without the contribution of the plurality of super-capacitors 30 , such an instantaneous variation in electric power would have been completely dependent on the fuel cell 10 alone which, due to a greater inertia in the response , would not have been able to dispense it instantly .

[ 0147 ] As it can be understood, the obj ect of the present invention is fully achieved since the electrical apparatus for connecting an electrical load to at least one fuel cell has various advantages , some of which have already been indicated above .

[ 0148 ] In fact , the electrical apparatus in accordance with the present invention advantageously allows to also integrate an alternative technology with a low environmental impact into an electric power supply network on board a ship, such as a fuel cell generator, which can be used to power an electrical load of the ship and thus reduce the environmental impact of the ship as much as possible .

[0149] The plurality of super-capacitors 30 present in the apparatus 100 has an active role in cases of an instantaneous ("step" ) variation of the electrical load L . [0150 ] In fact , the plurality of super-capacitors 30 , by electrically discharging, is able to dispense the instantaneous variation in electric power required by the electrical load L to at least one fuel cell 10 .

[0151 ] On the contrary, without the contribution of the plurality of super-capacitors 30 , such an instantaneous variation in electric power would be completely dependent on the fuel cell 10 alone which, due to a greater inertia in the response, would not be able to dispense it instantly .

[0152 ] Moreover, the logic control unit of the first switch with which the electrical apparatus 100 can be provided advantageously allows switching, without interrupting the power supply of the electrical load, to take and maintain a first operating configuration of the electrical apparatus , in which the electrical load L is powered by means of the at least one fuel cell 10 , during the normal operation of the at least one fuel cell and of the electrical apparatus , and switching, always without interrupting the power supply of the electrical load, to take and maintain a second operating configuration, in which the electrical load L is powered by means of the onboard electric power supply network 200 , if a malfunctioning condition occurs in at least one of the at least one fuel cell and the electrical apparatus .

[0153] Moreover, a second switch with which the electrical apparatus 100 can be provided is advantageously manually operable, without interrupting the power supply of the electrical load, to connect the electrical load to the onboard electric power supply network of the ship by means of a bypass electric power supply connection, effectively excluding the connection of the output terminal of the first switch with the electrical load, if the electric power converter of the DC/AC type is put out of service .

[0154 ] The apparatus in accordance with the present invention advantageously has :

[0155 ] - a reduction of the stages for converting the power to a single DC/AC inverter ( the converter 40 ) capable of ensuring a stable electrical output voltage on the AC side ( amplitude and frequency) during the entire operating range of the at least one fuel cell , despite the wide variation of the electrical output voltage thereof with the load;

[0156] - the optimi zation of the electric power conversion ef ficiency achieved by reducing the stages for converting power to a single DC/AC inverter capable of ensuring a stable AC output ( amplitude and frequency) throughout the operating range of the at least one fuel cell , although this type of electric generator is conventionally characterized by a wide travel of the electrical output voltage thereof as the load varies ( the electrical voltage of a fuel cell is in fact reduced by about 50% going from an " idle" operation to a 100% load) ;

[0157 ] - the integration of an energy storage system ESS based on super-capacitors which directly shares the same connection of the DC type with the at least one fuel cell ; in this respect, the use of super-capacitors has numerous advantages ( including greater safety) with respect to the use of batteries and allows the installation of the converter 40 , therefore of the apparatus , in the same room as the at least one fuel cell ;

[0158 ] - the presence of a second input line (bypass ) from the on-board electric power supply network 200 connected to a static switch ( first solid state line switch) ; such a static switch of the unit has two electrical input voltages : one from the on-board electric power supply network 200 , the other generated by the converter 40 (DC/AC inverter) ; the internal control logic unit is configured to synchroni ze the two electrical input voltages to the first switch . This configuration advantageously ensures continuity of power supply without blackouts to the load in the case of shutdown or failure of the fuel cell system if at least one fuel cell is used as an alternative electric power supply source to the load;

[0159] - the presence of a manually operated bypass switch ( second switch) which ensures continuity of power supply to the load without blackouts in the case of maintenance of the apparatus .

[0160 ] Independently of the presence of electric power supply coming from the shipboard electric power supply network on the aforesaid second input line (bypass ) , when the at least one fuel cell is in operation and connected to the apparatus 100 , thus to the converter 40 , the following sequence of operations is performed :

[0161 ] - if discharged, the plurality of super-capacitors is recharged by means of the resistor 60 ;

[0162 ] - the plurality of input capacitors arranged on the DC side of the converter 40 are charged by means of a special resistor and a charging contactor, first open and then closed at the end of the step, electrically connected in parallel and present inside the electrical pre-charge module 50 ;

[0163] - the converter 40 ( DC/AC inverter ) is switched on;

[0164 ] - the first switch ( static switch) is switched without blackout under the converter 40 .

[0165 ] The load is powered by the DC/AC inverter branch - static switch of the apparatus .

[0166] The at least one electricity storage unit based on super-capacitors is used in "peak shaving" mode, i . e . , the super-capacitors are discharged by means of the diode 61 in the case of " step-up" loads ( the electric power demand is greater than the output of the at least one fuel cell ) and are recharged by the at least one fuel cell during the load step-down while the electric power of the at least one fuel cell slowly decreases to satisfy the reduced demand for electricity .

[0167 ] In the presence of electric power supply coming from the shipboard electric power supply network, in the case where

[0168 ] - the output of the converter 40 (DC/AC inverter) is out of range due to an internal fault, or

[0169] - the at least one fuel cell is turned off ,

[0170 ] the first switch is switched without blackout under the bypass line and the load is powered by the shipboard electric power supply network by means of the second bypass input line - static switch branch of the apparatus .

[0171 ] In the presence of electric power supply coming from the shipboard electric power supply network, if the converter 40 ( DC/AC inverter) or the static switch of the apparatus requires maintenance, the manual bypass switch ( second switch 80 ) is activated .

[0172 ] Without a blackout occurring on the load, the static switch is isolated in output ( the manual bypass switch) and the load is switched to the shipboard electric power supply network by means of the bypass electric power supply connection B-P .

[0173] The converter 40 ( DC/AC inverter ) and the static switch are thus isolated by opening suitable input switches present on the direct connection between the at least one fuel cell and upstream of the second switching block C2 of the first switch 70 and by disconnecting the plurality of super-capacitors 30 by opening a suitable electrical switch interposed between the plurality of super-capacitors 30 and the electric node N1 . Once isolated, the plurality of super-capacitors 30 can thus be discharged onto a further resistor placed in parallel by closing a special electrical switch .

[0174 ] In order to meet contingent needs , those skilled in the art may make changes and adaptations to the embodiments of the electrical apparatus described above , and replace elements with others which are functionally equivalent, without departing from the scope of the following claims . Each of the features described as belonging to a possible embodiment can be made irrespective of the other embodiments described .

Claims

1. An electrical apparatus (100) for connecting an electrical load (L) of a ship (1) to at least one fuel cell (10) , the electrical apparatus (100) comprising: at least one electricity storage unit (20) configured to be connected to said at least one fuel cell (10) in a respective electric node (Nl) , said at least one electricity storage unit (20) comprising a plurality of super-capacitors (30) connected to the electric node (Nl) , the at least one fuel cell (10) being adapted to charge, during a step of initializing the apparatus (100) , the plurality of super-capacitors (30) of the at least one electricity storage unit (20) ; an electric power converter (40) of the DC/AC type operatively connected between the electric node (Nl) for the connection of the at least one fuel cell (10) with the at least one electricity storage unit (20) and the electrical load (L) , the electric power converter (40) of the DC/AC type being configured to allow the electric node (Nl) for the connection of the at least one fuel cell (10) with the at least one electricity storage unit (20) and the electrical load L to be directly connectable to the at least one fuel cell (10) , the converter (40) comprising a plurality of input capacitors arranged on the DC side of the converter (40) , said converter (40) being configured to receive a direct electric current as input and to supply the electrical load (L) with a respective alternating electrical voltage; an electric pre-charge module (50) arranged between the electric node (Nl) for the connection of the at least one fuel cell (10) with the at least one electricity storage unit (20) and the converter (40) , the electric pre-charge module (50) being configured to pre-charge, during the step of initializing the apparatus (100) , the plurality of input capacitors arranged on the DC side of the converter (40) , the at least one electricity storage unit (20) being configured to electrically discharge, at least partially, the plurality of super-capacitors (30) in the case of an instantaneous variation of the electrical load (L) , and to supply the electrical load (L) with the corresponding instantaneous variation of electric power required by the electrical load (L) to the at least one fuel cell (10) .

2. The electrical apparatus (100) according to claim 1, wherein the at least one electricity storage unit (20) further comprises a resistor (60) arranged in series with the plurality of super-capacitors (30) between the electric node (Nl) and the plurality of super-capacitors (30) , the at least one electricity storage unit (20) comprising a diode (61) connected at the ends to the resistor ( 60 ) , the resistor (60) being configured to limit the electric current absorbed by the plurality of supercapacitors (30) during a respective charging step, the diode (61) being configured to allow the passage of the electric current dispensed by the plurality of super-capacitors (30) , during the respective discharging step, to supply the electrical load (L) with the corresponding instantaneous variation of electric power required by the electrical load (L) to the at least one fuel cell (10) .

3. The electrical apparatus (100) according to any one of the preceding claims, wherein the electric power converter (40) of the DC/AC type comprises a three-phase inverter configured to convert the direct electric current received as input into alternating electrical voltage.

4. The electrical apparatus (100) according to any one of the preceding claims, wherein the alternating electrical voltage output from the converter (40) is adjusted by Pulse Width Modulation, PWM, control.

5. The electrical apparatus (100) according to any one of the preceding claims, further comprising a first switch (70) , the electrical apparatus (100) further comprising an electrical isolation transformer (85) directly arranged downstream of the converter (40) , the first switch (70) comprising: a first input terminal (Tl) operatively connected by means of the electrical isolation transformer (85) to the electric power converter (40) of the DC/AC type to receive the alternating electrical voltage; a second input terminal (T2) operatively connectable to an on-board electric power supply network (200) of the ship (1) to receive a further alternating electrical voltage supplied by the on-board electric power supply network (200) of the ship (1) ; an output terminal (T-U) operatively connectable to the electrical load (L) ; a first switching block (Cl) automatically operable to connect the output terminal (T-U) of the first switch (70) to the first input terminal (Tl) of the first switch (70) ; a second switching block (C2) automatically operable to connect the output terminal (T-U) of the first switch (70) to the second input terminal (T2) of the first switch (70) ; the first switch (70) further comprising a logic control unit configured to automatically operate the first switching block (Cl) and the second switching block (C2) without interrupting the power supply of the electrical load (L) between a first configuration of the electrical apparatus (100) adapted to supply the electrical load (L) with the alternating electrical voltage supplied by the converter (40) to power the electrical load (L) by means of the at least one fuel cell (10) and a second operating configuration of the electrical apparatus (100) adapted to supply the electrical load (L) with a further alternating electrical voltage to power the electrical load (L) by means of the on-board electric power supply network (200) of the ship (1) , if the alternating electric power supply voltage from the at least one fuel cell (10) through the converter (40) is not available.

6. The electrical apparatus (100) according to claim 5, wherein the logic control unit is configured to switch, take and maintain the first operating configuration of the electrical apparatus (100) during normal operation of the at least one fuel cell (10) and the electrical apparatus (100) .

7. The electrical apparatus (100) according to any one of the preceding claims 5 or 6, wherein the logic control unit of the first switch (70) is configured to switch, take and maintain the second operating configuration if a malfunctioning condition of at least one of the at least one fuel cell (10) and the electrical apparatus (100) occurs .

8. The electrical apparatus (100) according to any one of the preceding claims from 5 to 7, further comprising a second switch (80) manually operable without interrupting the power supply of the electrical load (L) to connect the electrical load (L) to the on-board electric power supply network (200) of the ship (1) by means of a bypass electric power supply connection (B-P) excluding the connection of the output terminal (T-U) of the first electronic switch (70) with the electrical load (L) , if the electric power converter (40) of the DC/AC type is put out of service.

9. The electrical apparatus (100) according to any one of the preceding claims, comprising a data processing unit and a user interface operatively connected to the data processing unit, the data processing unit being configured to provide, by means of the user interface, a plurality of information representative of an operating condition of the electrical apparatus (100) .

10. The electrical apparatus (100) according to claim 9, wherein the data processing unit of the electrical apparatus (100) is configured to determine and provide, by means of the user interface, a plurality of information representative of electrical parameters of the electrical apparatus (100) .

11. The electrical apparatus (100) according to any one of the preceding claims, further comprising a plurality of automatic circuit breakers (90) protecting the input and output electric power supply connections of the electrical apparatus (100) .

12. A method (300) for connecting an electrical load (L) of a ship (1) to at least one fuel cell (10) , the method (300) comprising steps of: providing (301) at least one electricity storage unit (20) configured to be connected to said at least one fuel cell (10) in a respective electric node (Nl) , said at least one electricity storage unit (20) comprising a plurality of super-capacitors (30) connected to the electric node (Nl) ; providing (302) an electric power converter (40) of the DC/AC type operatively connected between the electric node (Nl) for the connection of the at least one fuel cell (10) with the at least one electricity storage unit (20) and the electrical load (L) , the converter (40) comprising a plurality of input capacitors arranged on the DC side of the converter (40) , said converter (40) being configured to receive a direct electric current as input and to supply the electrical load (L) with a respective alternating electrical voltage; charging (303) , by the at least one fuel cell (10) , during a step of initializing the apparatus (100) , the plurality of super-capacitors (30) of the at least one electricity storage unit (20) ; pre-charging (304) , by an electric pre-charge module (50) arranged between the electric node (Nl) for the connection of the at least one fuel cell (10) with the at least one electricity storage unit (20) and the converter (40) , during the step of initializing the apparatus (100) , the plurality of input capacitors arranged on the DC side of the converter (40) ; in the case of an instantaneous variation of the electrical load (L) , electrically discharging (305) , at least partially, the plurality of super-capacitors (30) and supplying (306) the electrical load (L) , by the at least one electricity storage unit (20) , with the corresponding instantaneous variation of electric power required by the electrical load (L) to the at least one fuel cell (10) .

13. An electric power supply system (400) for an electrical load (L) of a ship (1) , comprising: an on-board electric power supply network (200) ; at least one fuel cell (10) ; an electrical apparatus (100) according to any one of the preceding claims 1 to 11.

14. A ship (1) comprising an electric power supply system (400) for an electrical load (L) of the ship (1) according to claim 13.