FR3064124A1 - SYSTEM FOR SUPPLYING ELECTRIC ENERGY, IN PARTICULAR FROM A NETWORK OF A SUBMARINE - Google Patents

Abstract

This system, comprising means (1) for storing energy based on lithium batteries and means (5, 10, 12) for distributing this energy to user loads, comprising means (9, 11 , 14) for breaking and isolating branches (13) for connecting the user loads, in particular in the event of a short-circuit, is characterized in that it comprises means (17) for monitoring the evolution of the current output of the energy storage means for detecting 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 in the event of such detection, means (16) for connection to the network, means (15) for generating a controlled short-circuit current, for triggering the operation of the means (14) for breaking and isolation associated with the branch in short circuit (13), in order to isolate the latter from the rest of the network, means (16) for disconnecting the ge short circuit current generator (15) of the network, and means (6, 7, 8) for reconnecting the electrical energy storage means to the rest of the network.

Description

Holder (s): DCNS Société anonyme.

Extension request (s)

Agent (s): CABINET LAVOIX Simplified joint-stock company.

FR 3 064 124 - A1

ELECTRICAL ENERGY SUPPLY SYSTEM, PARTICULARLY FOR AN ONBOARD NETWORK OF A SUBMARINE.

_ This system, comprising means (1) of energy storage based on lithium batteries and means (5,

10, 12) for distributing this energy to user loads, comprising means (9, 11, 14) for cutting and isolating branches (13) for connecting user loads, in particular in the event of a short -circuit, is characterized in that it comprises means (17) for monitoring the evolution of the output current of the energy storage means to detect the appearance of a short circuit in the network, means (6, 7, 8) for disconnecting the energy storage means from the rest of the network in the event of such detection, means (16) for connection to the network, means (15) for generating a current of controlled short circuit, to trigger the operation of the means (14) of cut-off and isolation associated with the short-circuit branch (13), in order to isolate the latter from the rest of the network, means (16) of disconnection of the short-circuit current generator (15) from the network, and means (6, 7,

8) reconnecting the electrical energy storage means to the rest of the network.

Electric power supply system, in particular for an on-board network of a submarine

The present invention relates to a system for supplying electrical energy, in particular to an onboard network of a submarine.

More particularly, the invention relates to such an electrical energy supply system which comprises means for storing electrical energy based on lithium batteries.

These electrical energy supply systems also include means for distributing this electrical energy intended for user loads, these energy distribution means comprising means for cutting and isolating branches for connecting loads of network user, especially in the event of a short circuit.

Traditionally, the means of storing electrical energy for this type of application, for example in submarines, have been based on the use of lead-acid batteries.

The network protection equipment was then sized to be able to cut short-circuit currents, for example from this type of battery, these currents being able to rise to 50 kA, for example.

However, the current trend is to use lithium batteries and in particular lithium / ion batteries, as means of storing electrical energy for the type of applications envisaged.

However, the short-circuit currents of such lithium / ion batteries are much higher than the short-circuit currents of lead-acid batteries.

For example, values of 300 kA are cited, that is to say values six times higher than the short-circuit currents of lead-acid batteries.

The question then arises of how to cut or interrupt such short-circuit currents with network protection devices of prior design.

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

This chopper then makes it possible to limit the output current of each branch to a value set in advance.

Thus 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 chopper system is made complicated by the need for coordination between the different choppers of the different branches and a knowledge of the impedance downstream of the chopper for the solution to work properly.

Other solutions have been proposed, for example in document EP 1 641 066.

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

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

This document then proposes a system for managing the connections and disconnections of the branches and charging of the batteries.

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

In addition, it requires complex management of the capacities of the different branches of the battery during charging and discharging.

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

However, precise knowledge of the state of charge of a lithium battery is not simple.

Another solution for limiting and breaking short-circuit currents for high-capacity lithium batteries, in particular for submarine applications, was also presented in 2013.

This system proposes to insert, in the event of a fault in the network, a resistance in the power line of the branches of the battery to attenuate the value of the current by dissipating a high calorific energy.

A system of static switches, for example semiconductor, allows to divert the current in this resistor in case of overcurrent detected at the output of the battery branches.

This system requires a water refrigeration device and requires a complete study of the protection and selectivity plan of the electrical network of each type of submarine where it is located, in order to define the value of the resistance which will limit the current. short-circuit to a value allowing the operation of the electrical protection systems of the network.

Such a solution is described for example in document WO 2010/089338.

Thus these different solutions are based on a limitation of the current at the output of the battery branches in order to ensure network protection and network selectivity in the event of a fault, this limitation making it possible to ensure a current value supplied by the battery compatible with the characteristics of the network protection devices.

But we have seen that such systems are complex and complicated to set up or develop and implement.

The object of the invention is therefore to solve these problems.

To this end, the subject of the invention is a system for supplying electrical energy in particular to an onboard network of a submarine, of the type comprising means for storing electrical energy based on lithium batteries and means for distributing this electrical energy to user loads, these means of distribution comprising means for cutting and isolating branches for connecting user loads, in particular in the event of a short circuit thereof, characterized in that it includes:

means for monitoring the evolution of the output current of the electrical energy storage means to detect the appearance of a short circuit in the network,

means for disconnecting the electrical energy storage means from the rest of the network in the event of such detection,

means of connection to the network, means for generating a controlled short-circuit current, to trigger the operation of the breaking and isolation means associated with the branch in short circuit, in order to isolate the latter from the rest of the network,

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

- means for reconnecting the electrical energy storage means to the rest of the network.

According to other characteristics of the system according to the invention, taken alone or in combination:

the means for monitoring the evolution of the current delivered by the electrical energy storage means include means for analyzing the variation of this current over time to detect the appearance of a short circuit as soon as this variation exceeds a predetermined threshold;

- The electrical energy storage means comprise several branches in parallel, each of which comprises disconnection means;

- The battery disconnection means comprise piloted semiconductor switching members;

- the controlled semiconductor switching members include MOSFET transistors;

- The means for cutting and isolating the branches for connecting the user loads include circuit breakers;

the distribution means comprise at least one battery panel, at least one main panel and at least one secondary panel for distributing electrical energy, connected between the energy storage means and the user loads;

- It also includes means for measuring the insulation of the rest of the network after disconnection of the energy storage means, to avoid reconnecting these storage means to the network, in the event of detection of a network insulation fault. .

The invention will be better understood on reading the description which follows, given solely by way of example, and made with reference to the appended drawings, in which:

FIG. 1 represents the general structure of a part of an electrical energy supply system, in particular of an on-board network of a submarine,

- Figures 2 to 7 illustrate the operation of such a system according to a first embodiment, and

- Figures 8 to 16 illustrate the operation of such a system according to a second embodiment.

FIG. 1 shows a system for supplying electrical energy, in particular to an onboard network of a submarine.

This comprises means for storing electrical energy based on lithium batteries, designated by the general reference 1.

In fact, these energy storage means comprise several branches of batteries in parallel, designated by the general references 2, 3 and 4 for example in this figure 1.

Each of these branches is connected to a battery panel designated by the general reference 5, through connection / disconnection means, respectively 6, 7 and 8.

As will be described in more detail below, these connection / disconnection means comprise, for example, switching organs with piloted semi-conductive sem3064124, such as for example MOSFET transistors, inserted in the branches.

Of course, other semiconductor switching devices can be envisaged.

The battery panel 5 also includes a circuit breaker designated by the general reference 9.

This battery panel 5 is connected to at least one main electrical energy distribution panel, one of which is designated for example by the general 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.

Thus a branch is illustrated in this figure and it comprises a circuit breaker designated by the general reference 11 in this figure.

This supply branch makes it possible to connect this main electrical power distribution board 10 to at least one secondary electrical power distribution board, one of which is designated for example by the general reference 12 in this figure.

This secondary electrical power distribution board 12 supplies branches for connecting user loads, such as for example the branch designated by the general reference 13 in this figure, through branch cut-off and isolation means, comprising also for example a circuit breaker, designated by the general reference 14.

A short-circuit generator, designated by the general reference 15, is connected to the battery panel 5, through connection means in the form of a switch, designated by the general reference 16 in this figure, controllable at closing and at opening to connect or disconnect this generator 15 from the battery panel 5.

Such a supply structure is then relatively conventional insofar as the means for storing electrical energy comprise branches of lithium batteries, connected to a battery panel, itself connected through a cascade of main and secondary panels. of distribution, to branches of connection of user loads.

Each of these tables includes breaking and isolation means, for example based on circuit breakers, which are then calibrated according to their location in the supply cascade, to cut the corresponding branch and isolate it from the rest of the network.

Unlike the systems of the prior art, which proposed limiting the value of the short-circuit current at the output of the battery system, in the system according to the invention, it is proposed to disconnect the battery before it has reached its maximum short-circuit current value.

Cutting means comprising semiconductor members are then used for this purpose.

To illustrate the problem mentioned above concerning the value of the short-circuit current of lithium batteries, we can take as an example the case of putting several battery packs in parallel for applications of several hundred kilowatts / hour.

The system short-circuit current can reach extremely high values.

For example if we consider fifty battery packs in parallel each of which can supply 4 kA, this results in a short-circuit current of the system of the order of 20 kA.

Conventionally, a direct current fuse according to current technologies has a breaking capacity of only 100 kA maximum and must be changed after melting, which, in the applications mentioned, is not possible or at least is not possible. is not acceptable, for reasons of accessibility and rapid availability of energy after a fault.

Likewise, a DC circuit breaker, which can be reset, also has a breaking capacity of only around 100 kA according to current technologies.

Thus, these systems are not designed to be able to cut short-circuit values beyond this value.

This is the reason why the invention proposes to act before the short-circuit current has reached its maximum value.

This makes it possible to limit the short-circuit current below values acceptable by the circuit breaker (s) or the fuse (s) as described, to guarantee the opening of the circuit while remaining in the zone in which the protective equipment is suitable for interrupting current.

Another aspect to take into account when dimensioning the protection of such a circuit, and in particular when calibrating circuit breakers, is the selectivity of the different elements of the whole chain or cascade of circuit breakers or fuses. the electrical distribution of the system.

To do this, the short-circuit current must be controlled.

In particular, it should not be limited too low under penalty of seeing certain circuit breakers open too slowly, or even not opening at all, which would be dangerous for the protection of the network in general and of the various components thereof. in particular.

Neither should the battery pack limit the short-circuit current to a level such that it does not trip the protections downstream of the electrical distribution in the network, otherwise the entire installation will be completely in default for the slightest local fault.

To this end, in the power supply system according to the invention, means are used to monitor the evolution of the output current of the electrical energy storage means to detect the appearance of a short circuit in the network.

In particular, these monitoring means analyze the variation of this current over time to detect a crossing of a triggering threshold threshold characteristic of a short-circuit fault for example.

These monitoring means are designated by the general reference 17 in FIG. 1.

These current monitoring means are then used to trigger the operation of the various means and organs of protection of the system and of the network, in order to ensure the overall protection of the network, the selectivity of the triggering and the provision of electrical energy of which is important for this type of application.

Is illustrated in Figures 2 to 7, a first embodiment of such a system.

We recognize in these Figures 2 to 7, the different elements which have already been described with reference to Figure 1.

When a fault occurs on one of the user load branches such as for example branch 13, as illustrated in FIG. 2, the means 17 for monitoring the evolution of the output current of the means of electrical energy storage, detect the appearance of this fault and in particular of a short circuit in the network.

This monitoring is a fact for example an analysis of the variation of the current over time in a conventional manner.

In response to this detection of this short circuit, the system triggers the disconnection of the electrical energy storage means from the rest of the network, by opening the semiconductor switching members 6, 7 and 8, as illustrated in the figure 3.

Once these semiconductor switching members are open, the system connects to the network and more particularly to Table 5, the short-circuit generation means 15, as illustrated in FIG. 4, by closing the connection means 16.

As indicated above, these generation means are adapted to cause a controlled short-circuit current, making it possible to trigger the operation of the cut-off and isolation means associated with the branch in short-circuit fault, in order to isolate it from the rest of the network, as illustrated in ia figure 5.

Indeed, the chain or cascade of network protection circuit breakers, located at the different levels of the latter, is designed and calibrated to allow the selectivity mentioned above to be obtained, for opening faulty branches like branch 13.

This then isolates the branch and the fault from the rest of the supply circuit.

Once this fault has been isolated, the system opens the means 16 for connecting the short-circuit generator to disconnect it from the network.

The circuit breaker 14 of the faulty user load branch, for example 13 being open, it is then possible to reconnect the battery to the network to make electrical energy available again, by closing the semiconductor switching members 6, 7 and 8, as illustrated in FIG. 7.

This allows the power supply to the network to be restored with the exception of faulty branch 13.

It is understood that such a structure has a number of advantages.

Indeed, by monitoring the evolution of the output current of the electrical energy storage means, and in particular, by analyzing the variation of this current over time to detect the appearance of a short circuit, as soon as this variation exceeds a predetermined threshold, it is possible to anticipate the operation of the network security and protection means.

In response, the system firstly disconnects the battery.

Then the short-circuit generation means are connected to the network to trigger the protection circuit breaker of your faulty user load branch.

This isolates this fault from the rest of the network.

The short circuit generator is then disconnected from the network and it is possible to reconnect the battery to this network to make electrical energy available.

In FIGS. 8 to 16, an alternative embodiment of this system has been illustrated, which also incorporates means 20 for measuring the insulation of the rest of the network after disconnection of the electrical energy storage means, in order to avoid sizing the means 16 so that they can withstand the short-circuit current of the generation means 15, upon closure.

The general operation of this embodiment of the system according to the invention is very close to that which has been described previously.

Indeed, when detecting the appearance of a fault, figure 8, the system disconnects the battery from the network, figure 9.

Then, as illustrated in FIG. 10, the system opens the circuit breaker 9 of the battery panel 5, to allow, in FIG. 11, the means 20 to measure the insulation of the rest of the network and determine whether it is possible or not to continue the process of isolating the fault as described.

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

This then makes it possible to cause the circuit breaker associated with the faulty branch to open, as illustrated in FIG. 14, to isolate it from the rest of the network.

The disconnection of the short-circuit current generator is illustrated in Figure 15 and the reconnection of the battery in Figure 16.

It is therefore understood that in the system according to the invention, semiconductor means based on MOSFET transistors are used for example, at the output of each branch of the battery, the functionality of which is to open quickly, for example in a time less than 100 microseconds, in the event of detection of an excessive rise in current.

This then makes it possible to disconnect the battery before the latter has established its nominal short-circuit current value.

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

Its function is to provide sufficient short-circuit current to eliminate the short-circuit by opening the protective equipment of the faulty branch.

Once the fault has been eliminated, the short-circuit current generator is isolated from this network and the battery is reconnected to the network.

Different technologies for short-circuit current generators can be envisaged, such as for example electromechanical technology.

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

Of course, still other embodiments can be envisaged.

Claims (7)

1. - System for supplying electrical energy in particular to an on-board network of a submarine, of the type comprising means (1) for storing electrical energy based on lithium batteries and means (5, 10, 12) for distributing this electrical energy to user loads, these distribution means comprising means (9, 11, 14) for cutting and isolating branches (13) for connecting user loads in particular in the event of a short circuit thereof, characterized in that it comprises: - means (17) for monitoring the evolution of the output current of the electrical energy storage means to detect the appearance of a short circuit in the network, - means (6, 7, 8) for disconnecting the electrical energy storage means from the rest of the network in the event of such detection, - means (16) for connection to the network, means (15) for generating a controlled short-circuit current, to trigger the operation of the means (14) of cut-off and isolation associated with the branch in short- circuit (13), in order to isolate it from the rest of the 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. 2, - Power supply system according to claim 1, characterized in that the means (17) for monitoring the evolution of the current delivered by the electrical energy storage means comprise means for analyzing the variation of this current over time to detect the appearance of a short circuit as soon as this variation exceeds a predetermined threshold. 3, - Power system according to claim 1 or 2, characterized in that the means (1) for storing electrical energy comprise several branches in parallel (2, 3, 4) each of which comprises disconnection means (6 , 7, 8). 4. - Power supply system according to any one of the preceding claims, characterized in that the disconnection means (6, 7, 8) of the battery comprise controlled semiconductor switching members. 5, - Power supply system according to claim 4, characterized in that the controlled semiconductor switching members comprise MOSFET transistors. 5 6, - Power supply system according to any one of the preceding claims, characterized in that the means for cutting and isolating the branches for connection of user loads include circuit breakers (14). 7, - Power system according to any one of the preceding claims 10, characterized in that the distribution means comprise at least one battery table (5), at least one main table (10) and at least one secondary table (12) of electrical energy distribution, connected between the energy storage means and the user loads. 8. A power supply system according to any one of the preceding claims, characterized in that it further comprises means (20) for measuring the insulation of the rest of the network after disconnection of the energy storage means, to avoid reconnecting these storage means to the network, in the event of detection of a network isolation fault.