KR102530250B1 - System for supplying electrical energy to the submarine's on-board network - Google Patents

Abstract

The present invention relates to an electrical energy storage means (1) based on a lithium battery and means (9, 11, 14) for supplying electrical energy of the type comprising power distribution means (5, 10, 12), in particular to the on-board network of a submarine, of said energy storage means for detecting the occurrence of a short circuit in the network. means (17) for monitoring the occurrence of an output current; means (6, 7, 8) for disconnecting the energy storage means from the rest of the network upon such detection; Means for connecting to the network (16), means for generating a controlled short-circuit current to trigger the operation of the cut-off and disconnect means (14) associated with the short-circuited branch (13) to isolate the short-circuited branch from the rest of the network ( 15); means (16) for disconnecting the short-circuit current generator (15) from the network; and means (6, 7, 8) for reconnecting the electrical energy storage means to the rest of the network.

Description

System for supplying electrical energy to the submarine's on-board network

The invention relates to a system for supplying electrical energy to an on-board network of a submarine.

More specifically, the present invention relates to such an electrical energy supply system comprising an electrical energy storage means based on a lithium battery.

These electrical energy supply systems also include means for distributing this electrical energy intended for user loads, which in particular include means for cutting off and disconnecting the branch for connecting the user load in the event of a short circuit.

Conventionally, electrical energy storage for this type of application, for example for submarines, is based on the use of lead batteries.

The protective equipment in the network is dimensioned to interrupt short-circuit currents, for example for this type of battery, which can reach, for example, up to 50 kA.

The current trend so far is to use lithium batteries, and in particular lithium ion batteries, as electrical energy storage for the type of application considered.

So far, the short-circuit current of these lithium-ion batteries is much higher than that of lead-acid batteries.

A value of eg 300 kA, ie a value six times higher than the short-circuit current of lead batteries is mentioned.

The question then arises how to cut off or break these short-circuit currents with the grid protection equipment of the initial design.

The applicant has already proposed to reduce the short-circuit current in case of an internal or external fault by inserting an electrical energy storage system, for example a current clipper, into the power line of each branch comprising the electrical energy storage system in parallel. .

The clipper can then limit the output current of each branch to a pre-configured value.

Therefore, the short-circuit current is limited to a value compatible with the characteristics of the protective equipment of the network to which the battery is connected.

However, the development of this type of system with clippers is complicated by the coordination between different clippers in different branches and the need for knowledge of the impedance downstream of the clippers for proper operation of the solution.

Another solution has been proposed, for example in reference EP 1,641,066.

In this reference, it is proposed to make the battery branch-by-branch to limit the short-circuit current.

The basic idea of this structure is to limit the short-circuit current by connecting only a limited number of branches.

This reference proposes a system for managing the connection and disconnection of branches and for charging batteries.

This system requires a discharge circuit and a charge circuit decoupled, for example by a diode.

Moreover, this requires complex management of the capacities of the different branches of the battery during charging and discharging.

This management requires very accurate knowledge of the state of charge of the branches to avoid excessive exchange current between the branches during connection and disconnection.

Until now, accurate knowledge of the state of charge of lithium batteries is not straightforward.

Another scheme for limiting and blocking short-circuit current for high-capacity lithium batteries, especially for submarine applications, was also announced in 2013.

This system proposes to attenuate the current value by dissipating high thermal energy by inserting a resistor into the power line of the battery branch in case of a network fault.

For example, a static switch system with semiconductors can deflect current across this resistor when an overcurrent is sensed at the battery branch output.

This system requires water cooling, and the protection and selectivity schemes of each type of submarine electrical network are installed to define the resistance value capable of limiting the short-circuit current to a value that permits the operation of the network's electrical protection system. A full study is required.

Such a solution is described, for example, in the reference WO 2010/089338.

Therefore, this other solution guarantees the protection of the network and the selectivity of the network in case of a fault, based on the limitation of the current at the branch output of the battery, which limits the current value supplied by the battery compatible with the characteristics of the network protection equipment. can guarantee

However, these systems have been found to be complex and difficult to develop and implement.

Accordingly, the present invention aims to solve this problem.

To this end, the present invention comprises means for storing electrical energy based on lithium batteries and distribution means comprising means for distributing this energy to user loads and in particular for cutting off and disconnecting branches for connection with user loads even in case of short circuits. A system for supplying tangible electrical energy, in particular to the on-board network of a submarine, comprising:

- means for monitoring the occurrence of the output current of the energy storage means in order to detect the occurrence of a short circuit in the network;

- means for disconnecting the energy storage from the rest of the network upon such detection;

- means for connecting to the network, means for generating a controlled short-circuit current to trigger operation of the cut-off and disconnecting means associated with the short-circuited branch to isolate the short-circuited branch from the rest of the network;

- means for disconnecting the short-circuit current generator from the network; and

- to a system for supplying electrical energy, characterized in that it comprises means for reconnecting the electrical energy storage means to the rest of the network.

According to another feature of the device according to the invention, the following means, alone or in combination, are considered:

- means for monitoring the generation of the current delivered by the electrical energy storage means comprising means for analyzing the change in this current with time in order to detect that a short circuit has appeared after the change in the current has exceeded a predetermined threshold; contains;

- the electrical energy storage means comprises a number of parallel branches, each branch comprising a disconnection means;

- the means for disconnecting the battery comprise a controlled semiconductor switching element;

- the controlled semiconductor switching element comprises a MOSFET transistor;

- the means for cut-off and disconnection of the branch for connection with the user load comprises a circuit breaker;

- the power distribution means comprises at least one battery panel, at least one main panel and at least one auxiliary panel for distribution of electrical energy, connected between the energy storage means and the user load;

- means for determining disconnection from the rest of the network, in case a disconnection fault of the network is detected, after disconnection of the energy storage means, to prevent the storage means from reconnecting to the network.

included in the context of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is provided by way of example only and will be better understood upon reading the following description with reference to the accompanying drawings.
1 shows the overall structure of a system for supplying electrical energy to an on-board network of a submarine.
2 to 7 show the operation of such a system according to the first embodiment.
8 to 16 show the operation of such a system according to a second embodiment.

1 illustrates a system for supplying electrical energy to a submarine's on-board network.

The system includes an electrical energy storage means based on a lithium battery, which is generally designated as reference number 1 .

In practice, this energy storage means comprises, for example, several parallel battery branches, designated overall reference numerals 2, 3 and 4 in this FIG. 1 .

Each of these branches is connected to the battery panel designated overall 5 through connection/disconnection means (6, 7 and 8 respectively).

As described in more detail below, this connection/disconnection means comprises for example a controlled semiconductor switching element, for example a MOSFET transistor, inserted in the branch.

Of course, other types of semiconductor switches may also be considered.

The battery panel 5 also includes a circuit breaker, generally designated 9 .

This battery panel 5 is connected to at least one main electrical energy distribution panel, one of which is for example designated overall reference 10 in this FIG. 1 .

This main electrical energy distribution panel 10 also includes, for example, several supply branches, each of which also includes a circuit breaker.

Accordingly, a branch is shown in this figure and includes a circuit breaker, generally designated 11, in this figure.

This supply branch makes it possible to connect this main electrical energy distribution panel 10 to at least one main electrical energy distribution panel, one of which is generally indicated at 12 in this figure, for example.

This auxiliary electrical energy distribution panel 12 has a branch for connecting to the user load via a branch cutoff and disconnection means also comprising a circuit breaker, eg generally designated 14, eg generally referenced 13 in this figure. Supply the branch specified by .

The short-circuit generator, designated overall reference number 15, is generally designated reference number 16 in this figure and is via a connection means in the form of a switch which can be controlled to open and close to connect or disconnect this generator 15 to or from the battery panel 5. It is connected to the battery panel (5).

This supply structure is relatively common, as long as the electrical energy storage means includes lithium battery branches connected to battery panels, which in turn are connected to branches for connection to user loads via a cascade of main and auxiliary distribution panels.

Each of these panels includes cutoff and disconnection means, for example based on a circuit breaker, which circuit breaker is then calibrated based on its position in the supply cascade to cut off the corresponding branch and disconnect it from the rest of the network. let it

In the system according to the invention, unlike systems of the state of the art proposed to limit the value of the short-circuit current at the output of the battery system, it is proposed to disconnect the battery before it reaches its maximum short-circuit current value.

For this purpose, a cut-off means comprising a semiconductor element is used.

To illustrate the aforementioned problem with respect to short-circuit current values of lithium batteries, consider an example where several battery packs are placed in parallel for applications of hundreds of kilowatts/hour.

The short-circuit current in the system can reach very high values.

For example, consider 50 packs of batteries side by side, each capable of providing 4 kA, which is reflected in a system short-circuit current of about 20 kA.

Typically, DC fuses according to current technology have a cutoff power of up to 100 kA and must be changed after a blowout, which is unimaginable or at least unacceptable for the accessibility and quick availability of energy after a fault in the applications mentioned. don't

Similarly, a restartable DC circuit breaker has a cutoff power of up to about 100 kA according to current technology.

Therefore, these systems are not designed to intercept short-circuit values above this value.

That is why the present invention proposes to operate before the short-circuit current reaches its maximum value.

This can, as described, limit the short-circuit current to below the value allowed by the circuit breaker(s) or fuse(s) to ensure the circuit is open while keeping the circuit in an area where the protective equipment can break the current.

Another aspect to be considered during the dimensioning of the protection of such circuits, and in particular the calibration of circuit breakers, is the selectivity of the distribution circuit breakers or other elements of the cascade of fuses or the entire chain of the system.

For this, the short-circuit current must be dominated.

In particular, some circuit breakers should not be limited so low that they open too slowly or not open at all, which can be dangerous to the protection of the network in general and other components in particular.

Also, the battery pack must not limit the short-circuit current to such an extent that it must not provide a circuit breaker to protect downstream of the power distribution in the network where even the slightest local failure would cause the entire installation to fail.

To this end, in the supply system according to the invention, means are used for monitoring the occurrence of the output current of the energy storage means in order to detect the occurrence of a short circuit in the network.

In particular, these monitoring means analyze the change of this current over time to detect, for example, a crossing of a limit trigger threshold characteristic of a short-circuit leakage.

This monitoring means is designated overall reference numeral 17 in FIG. 1 .

These current monitoring means are used to trigger the operation of other means and elements for protecting systems and networks in order to provide overall protection of the network, selectivity of triggering and optimal supply of new electrical energy, which is suitable for applications of this type. important to

2-7 show an exemplary embodiment of such a system.

In these FIGS. 2 to 7 , various elements can be seen which have already been described with reference to FIG. 1 .

As shown in Fig. 2, when an electric leakage occurs in one of the user load branches, for example branch 13, the means 17 for monitoring the occurrence of the output current of the electrical energy storage means is provided with this electric leakage, in particular the network detects the appearance of a short circuit of

Such monitoring is, for example, a conventional analysis of current fluctuations over time.

In response to this detection of this short circuit, the system triggers disconnection of the electrical energy storage from the rest of the network by opening the semiconductor switching elements 6, 7 and 8 as shown in FIG.

When these semiconductor switching members are open, the system connects the short-circuit generating means 15 to the network, more specifically to the panel 5, by closing the connecting means 16 as shown in FIG. 4 .

As mentioned above, these generating means are adapted to cause a controlled short-circuit current, so that they can trigger the operation of the cut-off and disconnection means associated with the short-circuit leakage branch, whereby as shown in FIG. can be isolated from the rest of the network.

In practice, circuit breaker chains or cascades protecting networks installed at different levels are designed and calibrated to obtain the aforementioned selectivity so as to be able to open a leakage branch such as branch 13.

Then, the branch and current leakage can be disconnected with respect to the rest of the supply circuit.

When this current leakage part is disconnected, the system disconnects it from the network by opening the connecting means 16 of the short circuit generator.

The circuit breaker 14 of the faulty user load branch is for example opened, and then the battery is reconnected to the network by re-closing the semiconductor switching elements 6, 7 and 8, as illustrated in FIG. Energy can be made available again.

This makes it possible to re-establish the network supply except for the faulty branch 13.

It can be seen that such a structure has several advantages.

In practice, by monitoring the generation of the output current of the electrical energy storage means, in particular by analyzing the fluctuation of this current with time to detect the appearance of a short circuit, if this fluctuation exceeds a predetermined threshold, safety and protection of the network The operation of the means can be predicted.

In response, the system first causes the battery disconnection.

The short-circuit generating means is then connected to the network to trigger the protective circuit breaker of the faulty user load branch.

Thus, it is possible to isolate this leakage part from the rest of the network.

The short-circuit generator is then disconnected from the network and the battery can be reconnected to this network to use electrical energy.

8 to 16 means for determining the disconnection of the remaining network after disconnection of the electrical energy storage means to prevent dimensioning the means 16 so as to be able to support the short-circuit current of the generating means 15 upon closure. An alternative embodiment of this system further comprising (20) is shown.

The overall operation of this embodiment of the system according to the present invention is very similar to that described above.

In fact, while it detects that a short circuit has occurred in FIG. 8, the system of FIG. 9 disconnects the battery from the network.

Then, as shown in Fig. 10, the system opens the circuit breaker 9 of the battery panel 5 so that, in Fig. 11, the means 20 determines the disconnection of the rest of the network and, as described, a short circuit. It allows us to determine whether the process of separating wealth can continue to evolve.

In this case, in FIG. 12 the short-circuit generator 15 is connected to the network by means 16 and in FIG. 13 the circuit breaker 9 of the battery panel 5 is closed.

This allows the opening of the circuit breaker associated with the earth leakage branch to be isolated from the rest of the network as shown in FIG. 14 .

Disconnection of the short-circuit current generator is shown in FIG. 15 and reconnection of the battery is shown in FIG. 16 .

Therefore, in the system according to the invention, semiconductor means are used, for example on the basis of MOSFET transistors, at the output of each branch of the battery, the function of which is to quickly open, for example in less than 100 ms, when an excessive current rise is detected. can know that

The battery can then be disconnected before the battery sets the nominal short-circuit current value.

A short-circuit current generator is then connected to the network.

Its function is to supply short-circuit current sufficient to clear the short-circuit by opening the protective device of the earth leakage branch.

When the current leakage part is removed, the short-circuit current generator is disconnected from this network and the battery is reconnected to the network.

Other short-circuit current generator technologies may be considered, for example electromechanical technologies.

The connection means of the short-circuit current generator may also be based on controlled semiconductor switching technology.

Of course, other embodiments are contemplated.

Claims (8)

comprising electrical energy storage means (1) based on lithium batteries and means (9, 11, 14) for distributing this energy to user loads and for cutting off and disconnecting branches (13) for connection with user loads even in the event of a short circuit A system for supplying, to the on-board network of a submarine, electrical energy of the type comprising distribution means (5, 10, 12) for
- means (17) for monitoring the occurrence of the output current of the energy storage means in order to detect the occurrence of a short circuit in the network;
- means (6, 7, 8) for disconnecting the energy storage means from the rest of the network upon such detection;
- in the form of a switch, of means 15 for generating a controlled short-circuit current to trigger the operation of the cut-off and disconnect means 14 associated with the short-circuited branch 13 to isolate the short-circuited branch from the rest of the network, means 16 for connecting to a network;
- means (16) for disconnecting the short-circuit current generator (15) from the network; and
- means (6, 7, 8) for reconnecting the electrical energy storage means to the rest of the network,
A system for supplying electrical energy, characterized in that the means for cut-off and disconnection of the branch for connecting to the user load comprises a circuit breaker (14). According to claim 1,
Means 17 for monitoring the generation of the current delivered by the electrical energy storage means analyze the fluctuation of this current over time to detect that a short circuit has occurred after the fluctuation of the current has exceeded a predetermined threshold. A system for supplying electrical energy comprising means for According to claim 1,
characterized in that the electrical energy storage means (1) comprises a plurality of parallel branches (2, 3, 4), each branch comprising a disconnection means (6, 7, 8). system for. According to claim 1,
A system for supplying electrical energy, characterized in that the battery disconnection means (6, 7, 8) comprise a controlled semiconductor switching element. According to claim 4,
The system of claim 1, wherein the controlled semiconductor switching member comprises a MOSFET transistor. delete According to claim 1,
The power distribution means comprises at least one battery panel (5), at least one main panel (10) and at least one auxiliary panel (12) for distribution of electrical energy, connected between the energy storage means and the user load. A system for supplying electrical energy characterized by According to claim 1,
further comprising means (20) for determining disconnection from the rest of the network, in case a disconnection fault of the network is detected, after disconnection of the energy storage means, to prevent the storage means from being reconnected to the network. A system for supplying electrical energy characterized by

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