AU2019316667A1 - Method for regulating the network of an underwater vehicle and underwater vehicle, which is designed for such regulating - Google Patents

Abstract

The invention relates to a method for automatic regulation of an electrical network of an underwater vehicle, and an underwater vehicle having an electrical network that is designed for carrying out a method of this type. The network comprises an electrical consumer (2), N_ges parallel arranged supply lines (VS.1, VS.N_ges), each having a voltage source (Sq.1, Sq.N_ges) and a voltage converter (G.1, G.N_ges) and a controller (1). According to the invention, the controller (1) chooses supply lines from among the supply lines N, specifically as a function of the current power consumption P of the consumer (2) and preferably of the states of the supply lines. The controller (1) controls the voltage converter (G.1,..., G.N_ges) such that the voltage converters of the N selected supply lines are in a load state and the other voltage converters are in an idle state. The consumer (2) is supplied from the N selected voltage sources. All supply lines (VS.1,..., VS.N_ges) of the network remain electrically connected to the consumer (2).

Description

Method for regulating the network of an underwater vehicle and underwater vehicle, which is designed for such regulating

The invention relates to a method for automatically regulating an electrical network of an underwater vehicle, and to an underwater vehicle having an electrical network, wherein the underwater vehicle is designed to carry out a method of this type.

An autonomously operating underwater vehicle is normally intended to travel underwater for a substantial amount of time without having to be connected to an 1o external voltage source. At least one electrical consumer, in particular an electric drive motor, is supplied by a plurality of electrical voltage sources. Voltage converters, normally DC voltage converters, convert the provided current into the voltage at which the consumer requires power.

The object of the invention is to provide a method having the features of the preamble to claim 1 and an underwater vehicle having the features of the preamble to claim 21 which enable the power losses which the voltage converters inevitably cause to be less than in the case of known methods, and in which a prompt response to power fluctuations is nevertheless possible.

This object is achieved by a method having the features indicated in claim 1 and an underwater vehicle having the features indicated in claim 21. Advantageous developments can be found in the subclaims, the following description and the drawings.

The underwater vehicle according to the solution comprises an electrical network. This electrical network comprises: - an electrical consumer, - Nges parallel-arranged supply lines, wherein N-ges is greater than or equal to 2, and - a signal-processing regulator.

Each supply line comprises, in each case:

- a voltage source, and - a voltage converter.

The respective voltage source of each supply line is electrically connected via the voltage converter of this supply line to the consumer. The voltage source is able to contribute to supplying the electrical consumer with electrical power at the required voltage. The electrical consumer is able to consume electrical power.

The respective voltage converter of each supply line can be operated in either at least one load state or at least one idle state.

A discharge adaptation step is performed at least once automatically. This discharge adaptation step comprises the following steps: - The regulator selects N supply lines from the N_ges supply lines of the network. The regulator makes this selection depending on the present power consumption P of the consumer. N is less than or equal to N_ges. - The regulator controls the voltage converters of the N_ges supply lines of the network with the following objective: following the control, the voltage converters of the N selected supply lines are in each case in a load state and the voltage converters of the remaining N_ges - N supply lines are in each case in an idle state.

The electrical consumer is supplied with electrical current by the N selected supply lines. At least one non-selected supply line from the N_ges - N non-selected supply lines of the network remains connected to the electrical consumer. It is possible for all non-selected N_ges - N supply lines of the network to remain electrically connected to the consumer.

The regulator is able to regulate the network fully automatically. A manual adjustment procedure by the user is not required. However, it can be provided that a user performs a manual adjustment procedure and thereby overrides and/or supplements a selection or control automatically performed by the regulator, for example switches a voltage converter from an idle state to a load state or electrically disconnects a supply line from the consumer.

The invention provides that the regulator automatically selects N supply lines. This selection depends on the present power consumption P of the consumer. An overload of a supply line can thereby be prevented, since a sufficient number of supply lines are selected and jointly supply the consumer.

In most cases, the consumer normally consumes only an electrical power which amounts to a fraction of the maximum available electrical power, often less than 10%. However, the full electrical power from the N_ges supply lines must be available in such 1o a way that it can quickly be automatically requested.

A voltage converter normally operates with a low power dissipation if it is in an idle state or operates with a high utilization, in particular at full load, for example according to a predefined U-I relationship. At full load, the voltage converter supplies a current intensity approximately equal to the maximum possible current intensity in continuous operation and/or the maximum possible power output during continuous operation at each voltage actually occurring during operation. "High utilization" is understood to mean a range above 75% of full load, preferably 80% of full load, particularly preferably 90%, more particularly preferably 95% of full load. The total power dissipation which the voltage converters of the network together cause is therefore low if as many voltage converters as necessary operate at full load and the remaining voltage converters are in an idle state. This results in a lower total power dissipation than if all voltage converters were operating in a halfway state between the full load and the idle state.

The invention enables at least one load state to be predefined in each case for each voltage converter. This load state can be an optimum operating point, for example an operating point at which the percentage power dissipation is minimal. The voltage converter operates at full load when it is switched to this load state. It is possible for the load state to be defined by a predefined U-I relationship, i.e. by a relationship which defines the current intensity to be output depending on the applied voltage.

The aim is thus for as many voltage converters of the N_ges supply lines as necessary to operate at full load, i.e., for example, in each case at an optimal operating point, and for the remaining voltage converters to be in the idle state. One conceivable possibility for achieving this is to activate or deactivate a supply line in each case with a power switch in such a way that the voltage converters of the connected and therefore active supply lines operate under load, for example at full load, and the voltage converters of the remaining supply lines are in the idle state.

The invention provides instead that all or at least more than the N selected N_ges 1o supply lines are left electrically connected to the consumer, the voltage converters of the N selected supply lines are switched to or are left in a load state and the voltage converters of the non-selected N_ges - N supply lines are switched to or are left in the or in each case an idle state. As a result, no power switch is required for a supply line in normal operation. Nevertheless, a power switch can obviously be provided in each case for each supply line, in particular in order to disconnect a defective supply line, or if the consumer is to be removed from the network.

According to the invention, a voltage converter in the idle state is not necessarily deactivated or even electrically disconnected from the network. Instead, the voltage converter remains activated and can be transferred from the idle state by means of an adjustment procedure into the or a load state. A supply line is activated by transferring a voltage converter from an idle state into a load state. A power switch is not required for this step.

One advantage of being able to eliminate power switches in normal operation is as follows: a power switch can be operated in two states only, i.e. it is either closed or opened. A supply line can therefore only be activated or deactivated abruptly by means of a power switch, so that the state of the network inevitably changes abruptly. A voltage converter, however, can also be modified gradually, for example successively or via a plurality of intermediate steps, and can thereby be gradually transferred from an idle state into a load state or vice versa. The state of the network is thereby changed gradually rather than abruptly. However, it is furthermore possible, if required, to transfer a voltage converter abruptly from the idle state into the load state or vice versa, for example if the consumer abruptly consumes more power. No power switch is required for this abrupt change either. The non-selected N - Nges supply lines are therefore on "hot stand-by". If a voltage converter is in the idle state, i.e. on hot stand by, this means that the voltage converter is controlled in such a way that it provides no energy to the assigned supply line, i.e., it feeds, for example, a voltage of 0 V or a current of 0 A into the supply line. An (electronic) switching element, for example, such as an IGBT (insulated gate bipolar transistor), is used to control the voltage converter.

However, it is also possible to disconnect individual voltage converters from the supply lines, i.e., in particular, to deactivate them. This can be done, for example, to balance the loads of the voltage converters. A voltage converter is, for example, operated for a considerable time period above the optimum operating point and has overheated. In this case, the voltage converter can first be deactivated in order to cool down quickly. Only when it has cooled down can it be switched once more to the idle state or to standby mode. The maximum service life of the voltage converter is therefore not shortened as a result of being exposed to a high temperature for too long. The voltage converter is, for example, de-energized in order to deactivate it. The preceding statements concerning the voltage converters are applicable accordingly to the voltage sources.

A further advantage of the invention compared with the use of power switches is as follows: a voltage converter can normally be switched from an idle state to a load state more quickly than a load switch and can thereby activate a further supply line. In some applications, the modification of a voltage converter further causes less noise than the switching of a power switch.

According to the solution, at least one non-selected supply line, preferably all N_ges supply lines of the network, remain connected to the consumer. If the power consumption of the consumer increases abruptly, the invention therefore enables the regulator to respond promptly. The regulator is thus enabled to control the voltage converter of at least one non-selected and electrically connected supply line in such a way that this voltage converter is similarly switched to the or a load state. There is no need to actuate a power switch, which requires more time.

In the event of a substantial increase in the power consumption, allowance is made for the fact that more than the N selected supply lines are then temporarily active. However, the requirement to supply the consumer even in the event of a sudden power increase is more important than a power dissipation which is at all times minimal.

In one preferred design, the regulator selects the N supply lines not only depending on 1o the present power consumption P of the consumer, but additionally depending on the present states of the N_ges supply lines of the network. As a result, the regulator responds automatically to significantly differing states of the supply lines, in particular to differing states of charge of voltage sources and differing levels of temperature increases. If a supply line is presently disconnected from the network, the regulator does not select it. Since the selection depends on the present power consumption P of the consumer in this design also, an overloading of a supply line is prevented.

In one design, an automatically evaluable discharge-number relationship and an automatically evaluable discharge-selection criterion are predefined. The predefined discharge-number relationship in each case defines a target number N_opt = Nopt(P) of simultaneously active supply lines of the network for a multiplicity of possible values for the power consumption P of the consumer and is preferably stored on board the underwater vehicle in a form that is automatically evaluable by the regulator. The predefined discharge-selection criterion depends on the states of the N_ges supply lines of the network.

According to this preferred design, the selection of the N supply lines depends on both the present power consumption P of the consumer and on the states of the N_ges supply lines. In one preferred embodiment of this design, the selection of the N supply lines is divided over two steps. In the step of selecting N supply lines, the regulator carries out the following steps:

- The regulator determines a target number N-opt(P). The discharge-number relationship assigns this determined number N_opt(P) of voltage converters to the present power consumption P of the consumer. - The regulator selects the N supply lines in such a way that N is greater than or equal to N-opt(P). For the selection of the N supply lines, the regulator applies the predefined discharge-selection criterion which depends on the present states.

The first step depends on the present power consumption P, but not on the operational states of the N_ges supply lines and, as a result, an optimum target number N_opt(P) is determined. The second step depends only on the target number N_opt(P) determined in the first step and on the states of the N-ges supply lines. Depending on these states, the N supply lines are selected in such a way that N is greater than or equal to N_opt(P). It is thereby ensured that at least the optimum number N_opt(P) of supply lines for the present power consumption P is selected. In addition, each selected voltage converter is thereby enabled to operate at an optimum operating point. Overloading of a supply line is furthermore prevented. It is possible for the regulator to select at least one further supply line, preferably one or two additional supply lines, in addition to the N_opt(P) supply lines in order to be able to leave the supply unchanged and not have to carry out a further selection in the event of a slight power increase. The number of additionally selected supply lines can be predefined in a fixed manner.

The discharge-number relationship can be predefined depending on characteristics of the voltage converters and/or the voltage sources, in particular depending on internal resistances of the voltage sources and/or on an optimum U-I relationship of a voltage converter.

The discharge-selection criterion can be adapted to predefined requirements, for example to the requirement that the voltage sources should, if possible, provide equally high voltages or should be kept at the same state of charge and/or the voltage sources and voltage converters should, if possible, be heated to an equal extent or should, for example, have the same number of hitherto performed charging and discharging cycles.

The service life of the voltage sources can therefore be extended through a suitable definition of the discharge-selection criterion.

The design wherein an optimum target number N-opt(P) is first determined and N supply lines are then selected in such a way that N is greater than or equal to N_opt(P) is a preferred design particularly if all supply lines of the network provide the same nominal electrical power and may differ only in terms of different positionings and different present operational states. Each voltage source comprises, for example, the same number of battery cells, and all battery cells are identical apart from having 1o different operational states.

In one variant, the possibility of at least two supply lines having different nominal powers is taken into account. In this variant, instead of a target number N_opt(P), a target total nominal power P_opt(P) is determined which defines the target nominal power to be provided in total by the supply lines depending on the present power consumption P. The regulator then selects the supply lines in such a way that at least the target total nominal power P_opt(P) is actually provided. In this design also, it is possible that the actually provided power is greater than the optimum target total nominal power P_opt(P).

The regulator preferably selects the N supply lines depending on at least one of the following criteria: - the current states of charge of the voltage sources, - the current temperatures of the voltage sources, - the current temperatures of the voltage converters, - the numbers of respectively hitherto performed charging procedures and/or discharging procedures for the voltage sources, and/or - the spatial positionings of the supply lines.

If the selection of the N supply lines depends on the states of charge, this enables the selection of those supply lines whose voltage sources currently have the best state of charge. In the discharging operation, for example, the regulator selects those N supply lines whose voltage sources have the highest states of charge, for example provide the highest voltage values, at the time of the selection. As a result, in particular, the currently most highly charged voltage sources can be discharged as a priority and therefore all voltage sources can be brought to states of charge which are as similar as possible.

If the selection of the N supply lines depends on the current temperatures, this enables currently intensely heated voltage sources and/or voltage converters to be deactivated and to be allowed to cool down as a result.

A voltage source is normally loaded by a charging procedure and/or loaded by a discharging procedure. If the number of N supply lines depends on the number of hitherto performed charging procedures or discharging procedures, voltage sources which have hitherto been frequently charged or discharged are less heavily loaded in future. The service lives of the voltage sources will differ less substantially from one another as a result of a suitable predefinition of the discharge-selection criterion. A maintenance operation in which at least one voltage source is repaired or exchanged is therefore normally less frequently required. Only one maintenance operation is required, for example, in which two voltage sources are serviced or exchanged, instead of two maintenance operations in each case for one voltage source.

If the selection of the N supply lines depends on the positionings of the N_ges supply lines, this enables the magnetic fields which the supply lines inevitably generate to mutually compensate one other at least partially and at least locally. The magnetic radiation of the network and therefore the electromagnetic signature of the underwater vehicle are thereby reduced.

In one design, the discharge adaptation steps are performed in a time-dependent manner, for example at a fixed sampling rate. Conversely, in one preferred design, they are performed in an event-controlled manner, for example depending on a predefined discharge execution criterion.

In one design, the following automatic response is triggered in the event that the power consumption P of the consumer has increased following a discharge adaptation step: the regulator or a special adaptation unit: - selects at least one of the currently non-selected supply lines, and - switches the voltage converter of the or of each additionally selected supply line to the or a load state. - The regulator then performs a discharge adaptation step once more.

This design ensures that a sufficient number of supply lines are active even after a io sudden increase in the power consumption, and therefore the required power can be provided without overloading a voltage source or a voltage converter. Optimum operation of the voltage converters and the voltage sources is furthermore enabled, even in the event of a sudden power increase, i.e. by the regulator once more performing a discharge adaptation step.

On the one hand, the design that has just been described enables a prompt response to a significant change in the power consumption. In particular, in the event of a sudden increase in the power consumption, it is ensured that at least one additional supply line is activated in a sufficiently short time by transferring its voltage converter into a load state. A supply line is prevented from being overloaded. The design with the special adaptation unit often enables a particularly prompt response to a sudden power increase. It is possible for the special adaptation unit to check each supply line successively according to a predefined sequence in order to determine whether it is already selected, and then to select at least the first supply line which has not yet been selected. This selection is preferably repeated until the selected supply lines can fulfil the sudden power increase. This special adaptation unit can respond promptly particularly if it is tasked solely with responding to a sudden power increase.

On the other hand, the design provides that a discharge adaptation step is performed once more following a significant change in the power consumption. This design thereby enables the number N of selected supply lines to be adapted immediately or after a short time to the present power consumption P and the states of the supply lines, as a result of which the voltage converters produce only a small amount of power dissipation.

In one design, automatic monitoring determines whether the power consumption P of the consumer has changed substantially since the last discharge adaptation step. This monitoring can be performed by the regulator or by a special adaptation unit. A substantial change means that the change meets a predefined discharge execution criterion. The change can mean that the power requirement is increased or reduced. The discharge execution criterion defines e.g. a lower limit for the percentage change or 1o absolute change in the power consumption. The discharge execution criterion is normally met, in particular, following a suddenly increased or suddenly reduced power requirement of the consumer. If the change in the power consumption meets the predefined discharge execution criterion, the regulator performs a discharge adaptation step once more in order to find a suitable number of active supply lines. The power dissipation is thereby reduced.

This design can be combined with the preferred response to a sudden power increase described above: at least one non-selected supply line is first automatically selected and a voltage converter of each now selected supply line is switched in each case to a load state. These steps can be performed by the regulator or by the special adaptation unit. The regulator then performs a discharge adaptation step once more in order to find a suitable number of active supply lines following the activation of at least one supply line.

The event-controlled selection of the N supply lines can also depend on the operational states of the supply lines. In one design, the regulator automatically monitors whether an operational state of at least one supply line has changed since the last discharge adaptation step. A substantial change again means that the change in the operational state meets a predefined selection execution criterion. At least in the case where the change in an operational state meets the predefined selection execution criterion, the regulator again selects N supply lines and switches or leaves the voltage converters of the N selected supply lines to or in a load state. It is possible, but not essential, for the regulator once more to determine an optimal number of supply lines to be selected. The reason for the further selection is in fact that an operational state of a supply line has changed, and not necessarily a changed power consumption P of the consumer.

On the one hand, this design enables the regulator to respond promptly to a significant change in the operational state of a voltage source or voltage converter. In particular, in the event of a sudden discharging of a voltage source or a substantial heating of a voltage source or voltage converter, it is ensured that this supply line is temporarily deactivated in a sufficiently short time by switching its voltage converter to the idle state, 1o and at least one other supply line is activated by transferring its voltage converter into a load state. It is not necessary to actuate a power switch in order to achieve this objective. All supply lines furthermore preferably remain electrically connected to the consumer.

The selection of the N supply lines preferably remains unchanged as long as neither the change in the power consumption nor the change in the operational states meets an execution criterion. This design ensures that the state of the network is changed only if the power consumption P of the consumer or the operational state of a supply line has not changed significantly. Minor changes which therefore have no impact on either the power dissipation or the operational states do not therefore cause a voltage converter to be transferred from one state into another state. This design therefore reduces the number of procedures performed by the regulator in the network.

In one design, a discharge-number relationship supplies an optimum number of active supply lines. According to the design, at least one further supply line is initially activated, particularly in response to a sudden power increase, and a discharge adaptation step is then performed once more. The fact that more supply lines are possibly temporarily active than would be optimal according to a discharge-number relationship is taken into account. However, it is normally more important to avoid an overload. Since the regulator again performs a discharge adaptation step, the optimum number of active supply lines can then be achieved once more.

In one design, at least one load U-1 relationship and at least one idle U-1 relationship are predefined in each case for each voltage converter. Each U-I relationship defines a current intensity to be supplied by the voltage converter depending on the value of the voltage applied to the voltage converter. The load U-I relationship produces a higher value for the current intensity to be supplied than the idle U-1 relationship at least in a value range for the voltage applied to the voltage converter in the case of an equal value for the applied voltage. If a voltage converter is in a load state, this voltage converter operates according to the or a load U-I relationship. If a voltage converter is in an idle state, this voltage converter operates according to the or an idle U-I relationship.

This design enables each voltage converter to operate in the load state close to full load without being overloaded. A voltage converter in the idle state can quickly be transferred into a load state if required, particularly in the event of a sudden power increase. The U-I relationships can be defined in such a way that the voltage converter causes minimal power dissipation and therefore produces little heat loss.

In one design, a U-I characteristic is predefined in each case for each voltage converter. This U-I characteristic defines the current intensity to be delivered by the voltage converter depending on the applied voltage and depends on a variable characteristic parameter. The greater the characteristic parameter, the greater the value for the current intensity defined by the U-I characteristic, at least in a value range for the voltage applied to the voltage converter in the case of an equal value for the applied voltage. The characteristic parameter of this voltage converter is increased in order to transfer a voltage converter from an idle state into a load state. The characteristic parameter of this voltage converter is reduced in order to transfer a voltage converter from a load state into an idle state.

This design enables a voltage converter to be transferred from one state into the other or another state via a plurality of intermediate steps. If the characteristic parameter can be continuously changed, the voltage converter can even be transferred steplessly from the one state into the other state. The state of the network is therefore gradually changed as a result of the design. It can be adapted to a gradually changing power consumption of the consumer, in fact preferably continuously and in such a way that the voltage converter always operates close to an optimum operating point. The speed at which the state of the network is changed depends on the speed at which the characteristic parameter is changed, and can therefore be controlled.

Conversely, the U-I characteristic can obviously also depend on the characteristic parameter, i.e. the smaller the value of the characteristic parameter, the greater the value of the current intensity.

It is possible for at least one supply line to be disconnected at least once from the consumer, for example because the supply line has overheated or because a fault has occurred in the supply line, particularly if the voltage source of this supply line is defective. In one design, the regulator responds to this event as follows: the regulator performs a discharge adaptation step once more. The or each disconnected supply line is not selected here. The N supply lines whose voltage converters are operated in the load state are therefore selected from the maximum N_ges - 1 remaining and non disconnected supply lines.

It is possible that the disconnected supply line has contributed to supplying the consumer with electrical current before being disconnected. According to this design, a discharge adaptation step is performed once more, wherein the disconnected supply line is excluded from the selection. It is thereby ensured, on the one hand, that the consumer is adequately supplied. On the other hand, the power losses caused by the voltage converters are reduced.

According to the solution, a voltage converter of a supply line can be operated in either a load state or an idle state. In one design, the voltage converter comprises power controllers, for example switching elements in the form of IGBT transistors or MOSFET transistors, and also a dedicated regulator for these power controllers. If the voltage converter is in the idle state, the power controllers are not switched or are set to a non switching mode. However, the power controller regulator continues to be supplied with current. The power controller regulator can therefore switch the voltage converter at any time to a load state if the power controller regulator is controlled accordingly by the higher-level regulator.

In one design, the N_ges voltage sources temporarily supply the electrical consumer and are in turn temporarily charged from at least one further voltage source, for example from an electrical generator or a fuel cell system. Each voltage source of the network is therefore capable of either outputting electrical energy to the consumer or receiving and storing electrical energy from the further voltage source. In this design, each supply line is permanently or at least temporarily connected to the further voltage 1o source.

In one preferred embodiment, a charging step is performed at least once. This comprises the following steps: - The regulator selects M supply lines of the network. - The regulator controls the voltage converters of the N_ges supply lines in such a way that at least the voltage converters of the selected M supply lines are in the or an idle state. - The voltage sources of the selected M supply lines are charged from the further voltage source.

Thanks to this design, the further voltage source does not supply the consumer with electrical current directly or exclusively directly, but instead indirectly via the voltage sources of the supply lines. It is therefore not necessary to provide an additional voltage converter which converts current from the further voltage source directly into current for the consumer. It is possible for the further voltage source to be electrically connected to the consumer and therefore via the voltage converters of the supply lines to the voltage converters of the supply lines also. These voltage converters are preferably designed as bidirectional.

The charging of the voltage sources also requires no adjustment procedure on the part of a user. Instead, in one design, the regulator automatically selects M supply lines and instigates the charging of the voltage sources of the M selected supply lines.

This design further enables at least one voltage source of a supply line to be charged during ongoing operation, provided that the further voltage source is electrically connected to the corresponding supply line in ongoing operation. This is the case particularly if the further voltage source is installed on board the underwater vehicle, for example a generator or a fuel cell system.

The further voltage source can also be disposed spatially distant from the underwater vehicle, for example on board a surface vessel or other platform. In this design also, the io electrical consumer continues to be supplied with current while the M selected voltage sources are being charged.

In one design, while the M selected voltage sources of the supply lines are being charged, the remaining N_ges - M voltage sources are deactivated. In another design, the selected N voltage sources remain active and supply the consumer with electric current.

It is not necessary to actuate a power switch in order to charge a voltage source. Thanks to the invention, it suffices to switch the connected voltage converter to the idle state or to leave it in the idle state or in the load state - depending on whether the voltage source of a supply line is connected via the voltage converter of this supply line or is otherwise electrically connected to the further voltage source. This supply line is furthermore preferably prevented from being selected for discharging while its voltage source is being charged. It is possible for the regulator to select a voltage source for charging if its state requires it. A special charging phase for the voltage sources is possible, but not essential.

The most heavily discharged voltage sources of the supply lines are preferably selected. The regulator generally performs the following steps when selecting the M voltage sources to be charged: - The regulator determines a target number M_opt of voltage sources to be charged, where M_opt is less than or equal to N_ges.

- When selecting the M supply lines, the regulator applies a predefined charge selection criterion depending on the states of the supply lines. Here, M is less than or equal to M_opt.

This target number M_opt preferably depends on a power parameter of the further voltage source. This design enables the further voltage source to be operated in an optimum operational state, wherein this operational state depends on the power parameter. The further voltage source is furthermore prevented from being overloaded.

1o The underwater vehicle with the electrical network according to the solution can be a manned or an unmanned underwater vehicle. It can have its own drive or can get by without its own drive. Its own drive can form part of the electrical consumer which is supplied by the supply lines. The underwater vehicle can be designed for military and/or civilian purposes.

The electrical consumer can contain a multiplicity of individual consumers. At least one individual consumer is preferably an electric drive motor which drives at least one shaft for the or a propeller of the underwater vehicle. At least one further electrical consumer can be an electrical drive mechanism or a sensor or an actuator, e.g. a gripper.

Each voltage converter converts current at the voltage at which the connected voltage source provides electrical energy into current at the voltage at which the consumer can consume current. The consumer can consume DC current or AC current. Depending on the design, a voltage converter can convert DC current into DC current or DC current into AC current or AC current into AC current. In one design, the network is an all-DC current network and contains consumers in the form of subnetworks which consume AC current.

In one design, the voltage sources of at least two supply lines supply current at different nominal voltages. The voltage converters are correspondingly differently designed and supply current at the voltage at which the consumer can consume the current.

In one design, at least one voltage converter, preferably each voltage converter, is a bidirectional voltage converter and is capable of feeding current which a further voltage source and/or the electrical consumer outputs into the voltage source connected to the voltage converter and is thereby capable of recharging this voltage source.

The method according to the invention and the electrical network of the underwater vehicle according to the invention are explained in detail below on the basis of an exemplary embodiment shown in the drawings, wherein:

Fig. 1 shows schematically a circuit diagram of the electrical network in which the invention is used; Fig. 2 shows schematically the dependence of the current intensity on the voltage in an application in which the invention is not used; Fig. 3 shows two examples of U-I characteristics for a DC voltage converter; Fig. 4 shows an example of a flow diagram for carrying out the method; Fig. 5 shows schematically the dependence of the current intensity on the voltage in an application in which the invention is used; Fig. 6 shows a detail enlargement from Fig. 3 shows two examples of U-I characteristics for a DC voltage converter; and, by way of example, the U-I characteristics of two DC voltage converters while the consumer is being supplied from N voltage sources; Fig. 7 shows the detail enlargement from Fig. 4 shows an example of a flow diagram for carrying out the method; while M voltage sources are being charged.

Fig. 1 shows schematically a circuit diagram of the electrical network in which the invention is used; shows schematically a circuit diagram of the electrical network in which the invention is used. This electrical network is installed on board a manned submarine. In Fig. 1 shows schematically a circuit diagram of the electrical network in which the invention is used; , the following components of this electrical network are shown:

- an electrical consumer 2 which is supplied with DC current at a voltage U_out and consumes electrical power, wherein the consumer 2 comprises a plurality of individual consumers, for example a drive motor for the submarine, - Nges supply lines VS.1, . . , VS.Nges, where N_ges is greater than or equal to 2 and is, for example, equal to 22, - a further voltage source 3 in the form of a fuel cell system, - a further voltage source 4 in the form of a generator, - a DC voltage converter G which connects the further voltage source 3 to the consumer 2 and to the N_ges supply lines, and 1o - a higher-level regulator 1.

The N_ges supply lines VS.1, . . , VS.Nges are arranged in parallel and together supply the electrical consumer 2. The two further voltage sources 3 and 4 are connected in parallel to the N_ges supply lines VS.1, . . , VS.N_ges and are capable of charging the voltage sources of the N-ges supply lines VS.1, . . , VS.Nges and similarly of supplying the consumer 2 with electrical current. A DC voltage converter G converts the DC voltage from the fuel cell system 3 into the DC voltage which the consumer 2 requires. The generator 4 supplies the DC voltage which the consumer 2 requires directly without a voltage converter.

In the embodiment shown in Fig. 1 shows schematically a circuit diagram of the electrical network in which the invention is used; , no power switches are required in normal operation. Instead, all N_ges supply lines VS.1, . . , VS.N_ges are always electrically connected to the consumer 2 in normal operation, unless a supply line is defective and therefore disconnected.

Each supply line VS.i (i = 1, . . , Nges) comprises the following components: - a sequence of Z batteries B.i.1, . . , B.i.Z which are connected in series and together form the voltage source Sq.i of the supply line VS.i, - a signal-processing battery management system MS.i which receives the present voltage values and further signals from the individual batteries B.i.1, . . , B.i.Z, and

- a bidirectional DC voltage converter G.i which converts the DC voltage supplied by the voltage source Sq.i into the voltage required by the consumer 2 and is also capable of performing the inverse conversion.

In the exemplary embodiment, each voltage source Sq.i has the same number Z of batteries, and all batteries B.i.1, . . , B.i.Z are of similar design. It is also possible for the voltage sources to have different numbers of batteries or different batteries.

Fig. 1 shows schematically a circuit diagram of the electrical network in which the io invention is used; shows the following measured values which are transmitted to the battery management system MS.i (i = 1, . . , Nges): - the value U(ij) of the voltage which the battery B.i.j of the supply line VS.i currently supplies (i = 1, . . , Nges, j = 1, . . , Z), - the value U_in(i) of the voltage which the supply line VS.i currently supplies in total, wherein the voltage is applied to the input of the DC voltage converter G.i (i = 1, N_ges), and - the value Iin(i) of the current intensity which the DC voltage converter G.i receives on the input side (i = 1, . . , Nges).

Fig. 1 shows schematically a circuit diagram of the electrical network in which the invention is used; further shows the following values which the battery management system MS.i determines and outputs: - the current state of charge SOC(i) of the voltage source Sq.i of the supply line VS.i, - the current maximum operating temperature Temp(i) of the supply line VS.i, and - the number Anz(i) of charging procedures and discharging procedures which have hitherto been performed for the voltage source Sq.i.

The battery management system MS.i continuously transmits the values SOC(i), Temp(i), Anz(i) to the regulator 1. The following values are further transmitted to the regulator 1:

- the value U-out(i) of the voltage which is applied to the output of the DC voltage converter (i = 1, . . , Nges), and - the value Iout of the current intensity which flows from the output of the DC voltage converter G.i (i = 1, . . , Nges) to the input of the consumer 2.

During fault-free operation, U_out(1)= ... = U_out(Nges) = Uout. Furthermore, I_out = Iout(1) + . . + I_out(Nges) + Iout(Sp.3) + I_out(Sp.4) applies, where I_out(Sp.3) is the intensity of the current supplied by the further voltage source 3 (fuel cell system) and Iout(Sp.4) is the intensity of the current supplied by the further voltage source 4 1o (generator).

The regulator 1 controls the DC voltage converters G.1,..., G.Nges of the N_ges supply lines depending on the values received. How this happens is explained below.

Fig. 1 shows schematically a circuit diagram of the electrical network in which the invention is used; shows schematically, by way of example, the dependence of the current intensity on the voltage for the network from Fig. 1 shows schematically a circuit diagram of the electrical network in which the invention is used; in an application in which the invention is not used. The total current intensity lout which flows into the consumer 2 is shown on the x-axis, and the total voltage U_out is shown on the y-axis. A positive value for the total current intensity I_out means that the N_ges parallel-connected supply lines VS.1, . . , VS.Nges provide voltage which is applied to the consumer 2, and current flows from the N voltage sources Sq.i(1), Sq.i(N) of the N activated supply lines VS.i(1), . . , VS.i(N) to the consumer 2. A negative value means that the further voltage source 3 or 4 charges the N_ges supply lines. It is possible for the further voltage source 3 or 4 additionally to supply the consumer 2 during the charging of the N voltage sources Sq.i(1), . . , Sq.i(N).

In the exemplary embodiment, the voltage converters G.1, . . , G.Nges of the N_ges supply lines VS.1, . . , VS.Nges are bidirectional voltage converters and can either:

- convert DC voltage from the DC voltage converter G or from the further voltage source 4 into DC voltage for the N voltage sources Sq.i(1), . . , Sq.i(N), or - convert DC voltage from the N voltage sources Sq.i(1), . . , Sq.i(N) into DC voltage for the consumer 2.

Fig. 1 shows schematically a circuit diagram of the electrical network in which the invention is used; shows, by way of example, a present operating point with a value of 326 A for the total current intensity out and a value of 505 V for the total voltage U-out. For N_ges = 22, io each supply line VS.i supplies current having a current intensity of 326 A/22 = 14.8 A. The DC voltage converters are operated in a state between full load and an idle state so that, in total, a relatively high power dissipation occurs.

Thanks to the invention, the power dissipation caused in total by the DC voltage converters G.1, . . , G.Nges is significantly reduced in many cases. One feature of the invention is that each DC voltage converter G.1, . . , G.Nges is operated in either at least one load state or at least one idle state. Whether a DC voltage converter G.1, . .

, G.N_ges is operated in a load state or in an idle state depends on the corresponding control which the regulator 1 performs. If a DC voltage converter G.i of a supply line VS.i operates in a load state, the voltage source Sq.i (the batteries B.i.1, . . , B.i.Z) of this supply line VS.i supplies current for the consumer 2 depending on the control of the DC voltage converter Gi, or this voltage source Sq.i is charged. If the DC voltage converter G.i is in an idle state, its local regulator is nevertheless supplied with voltage, and the DC voltage converter G.i can quickly be switched to a load state once more, whereby the local regulator controls switching elements of the DC voltage converter G.i accordingly. All batteries of a voltage source Sq.i either simultaneously output current or are simultaneously charged. An exemplary embodiment is described below to illustrate how a DC voltage converter G.i is operated and how its present state is changed.

In the exemplary embodiment, each DC voltage converter G.1,..., G.Nges operates according to a U-I characteristic. Fig. 1 shows schematically a circuit diagram of the electrical network in which the invention is used; shows, by way of example, the U-I characteristic for a DC voltage converter G.i. In Fig. 1 shows schematically a circuit diagram of the electrical network in which the invention is used; , the output-side current intensity Iout(i) of the DC voltage converter G.i is shown on the x-axis and the voltage U_out which the N_ges supply lines provide in total and which is applied to the consumer 2 and to the N-ges voltage converters G.1,..., G.N_ges is shown on the y-axis. The DC voltage converter G.i is controlled in such a way that, for a specific value for the voltage U_out, the DC voltage converter G.i supplies the value defined by the U-I characteristic for the current intensity Iout(i). A 1o positive value for the current intensity Iout(i) means that the voltage source Sq.i charges the electrical consumer 2. A negative value means that a further voltage source 3, 4 charges the voltage source Sq.i by means of the DC voltage converter G.i.

Fig. 1 shows schematically a circuit diagram of the electrical network in which the invention is used; shows, by way of example, an operating point AP. With a value Ux for the voltage U_out, the U-I characteristic defines a value Ix for the output-side current intensity I_out(i). A specific U-I characteristic is used for each DC voltage converter G.1, G.N_ges. All U-I characteristics are stored, for example, in computer-available form in the regulator 1. The specific U-I characteristic is stored in a working memory of the local regulator of the DC voltage converter G.i. An adjustment procedure performed by the regulator 1 on the DC voltage converter G.i effects a shift in this U-I characteristic.

According to the solution, each DC voltage converter G.i can be operated in either a load state or at least one idle state, depending on every other DC voltage converter. In the exemplary embodiment, the state in which the DC voltage converter G.i is operated is changed by shifting the U-I characteristic vertically. The currently used U-I characteristic is therefore described by a characteristic parameter, for example by the smallest value for the voltage U_out at which the current intensity Iout(i) is greater than zero. This vertical shift effects a change in the defined value for the current intensity I_out(i) in the case of an equal value for the voltage U_out. Fig. 1 shows schematically a circuit diagram of the electrical network in which the invention is used; shows, by way of example, two U-I characteristics, i.e. a U-I characteristic U-I.L(i) for a load state and a U-I characteristic U-I.R(i) for an idle state. The value Par.L of the characteristic parameter is associated with the U-I characteristic U-.L, and the value Par.R is associated with U-I characteristic U-I.R. In the exemplary embodiment, all U-I characteristics have the same form, but the characteristic parameter can currently have a different value for each DC voltage converter. Each DC voltage converter can be controlled independently of every other DC voltage converter, so that its value for the characteristic parameter can be changed independently of all other DC voltage converters.

Each DC voltage converter G.i of the exemplary embodiment is a bidirectional voltage converter. A positive value for the current intensity Iout(i) means that the DC voltage converter G.i outputs current on the output side which the supply line VS.i provides. A negative value for the current intensity Iout(i) means that the DC voltage converter G.i outputs current on the input side with which the voltage source Sq.i of the supply line VS.i is charged. As shown in Fig. 1 shows schematically a circuit diagram of the electrical network in which the invention is used; , the further voltage source 3, 4 is capable of charging the supply line VS.i, provided that the DC voltage converter G.i is controlled in such a way that its U-I characteristic provides a negative value for the current intensity Iout(i).

Fig. 2 shows schematically the dependence of the current intensity on the voltage in an application in which the invention is not used; shows an example of a flow diagram for carrying out the method. The following steps are performed and the following interim result is achieved here: - In step S1, the regulator 1 checks whether the voltage sources Sq.1, . . , Sq.N_ges of the supply lines VS.1, . . , VS.Nges presently supply the consumer 2 with electric current or whether the voltage sources Sq.1, . . , Sq.Nges are charged from at least one further voltage source 3, 4. This decision depends on the direction in which the current flows, i.e. on the sign which the current Iout has. The current intensity and the direction of Iout are transmitted to the regulator 1.

- Following the decision El, the method is continued either with the discharging of voltage sources ("DC" (discharge) branch), i.e. the consumer 2 is supplied with electrical current from some of the voltage sources of the supply lines VS.1, VS.Nges, or the charging of the voltage sources ("C" (charge) branch), i.e. the consumer 2 is supplied from at least one of the further voltage sources 3, 4, and the further voltage source 3, 4 charges voltage sources of the supply lines VS.1, VS.Nges. In the exemplary embodiment, voltage sources of the supply lines are either discharged or charged at any time, but the discharging of one voltage source and the charging of another voltage source do not take place simultaneously. - If the method is carried out with the "DC" (discharge) branch, the present electrical power consumption P is determined by the consumer 2 in step S2. P = Iout * Uout normally applies. This power consumption P = P(t) normally changes over time, i.e. it can increase or decrease. In one design, only the voltage U_out or only the current intensity I_out is monitored and the power consumption is derived therefrom. In an AC network, it is also possible to monitor the frequency f instead of the voltage or the current intensity. - In step S3, the regulator 1 automatically determines an optimum target number N_opt of simultaneously active supply lines of the network. To do this, the regulator 1 has read access at least temporarily to a computer-avaiable and automatically evaluable discharge-number relationship EAZ. This discharge-number relationship EAZ in each case defines a target number N-opt = Nopt(P) of simultaneously active supply lines for a multiplicity of possible values for the power consumption P of the consumer 2. These simultaneously active supply lines provide the electrical power for the consumer 2. The target number N-opt(P) increases with increasing power consumption P. - If the supply lines have different numbers or types of batteries, the regulator 1 uses a discharge-power relationship which defines the target nominal electrical power which the supply lines are intended to provide in total depending on the power consumption P of the consumer 2. - In step S4, the regulator 1 automatically selects N supply lines from the N_ges supply lines VS.1, . . , VS.Nges of the network. Here, N is greater than or equal to

N_opt(P). It is possible for the regulator 1 always to select at least one additional supply line for security, so that N is greater than N-opt(P). - If the voltage sources provide different nominal powers, e.g. due to different numbers or types of batteries, the regulator 1 selects N supply lines so that the voltage sources of the selected N supply lines together provide at least the determined target nominal power. - The regulator 1 uses a predefined discharge-selection criterion EAK in order to select the N supply lines. What this discharge-selection criterion EAK can depend on is described below. The N selected supply lines are denoted VS.i(1), . . , VS.i(N). - If a supply line is not currently connected to the consumer 2, for example because the supply line is deactivated or isolated with a power switch, this isolated supply line is not selected and the selection is restricted to the remaining N_ges - 1 supply lines. - In step S5, the regulator 1 controls the DC voltage converters of the supply lines of the network in such a way that the DC voltage converters G.i(1), . . , G.i(N) of the selected N supply lines VS.i(1), . . , VS.i(N) are switched to a load state and the remaining DC voltage converters are switched to or remain in an idle state. In one design, the regulator 1 causes the respective characteristic parameter of the DC voltage converter G.i(1), . . , G.i(N) of each selected supply line VS.i(1), . . , VS.i(N) to be set to a high value, and the characteristic parameter of a DC voltage of a non selected supply line to be set to a low value, cf. Fig. 1 shows schematically a circuit diagram of the electrical network in which the invention is used; . Fig. 2 shows schematically the dependence of the current intensity on the voltage in an application in which the invention is not used; - shows the U-I characteristics of the DC voltage converters G.i(1), . . , G.i(N) of the N selected supply lines VS.i(1), . . , VS.i(N) operated in the load state. - During the charging ("C" branch of decision El), the power P1 which the further voltage source 3 and/or 4 can presently output is initially defined in step S6. - In step S7, the regulator 1 applies a predefined charge-number relationship BAZ in order to define an optimum target number M-opt(P1) of voltage sources to be simultaneously charged. This target number M_opt(P1) depends on the determined power P1. It can further depend on the present operational state of the further voltage source 3 and/or 4 and also on whether the submarine is or is not presently connected to an external voltage source. - In step S8, the regulator 1 applies a predefined charge-selection criterion BAK in order to select those M supply lines whose voltage sources are intended to be charged from the N_ges supply lines. Here, M is preferably less than or equal to M_opt(P1) in order to prevent an overloading of the further voltage sources 3 and 4 and to ensure that the further voltage sources 3 and 4 can concurrently supply the consumer 2. The M supply lines selected for charging are denoted VS.j(1), VS.j(M). - In step S9, the regulator 1 controls the DC voltage converters of the supply lines of the network in such a way that the DC voltage converters G.j(1), . . , G.j(M) of the selected M supply lines VS.j(1), . . , VS.j(M) are in a load state. These selected DC voltage converters G.j(1), . . , G.j(M) convert DC current from the further voltage source 3 and/or 4 into DC current for the voltage sources Sq.j(1), . . , Sq.j(M). The DC voltage converters of the remaining supply lines are preferably set to an idle state.

Steps S1 and S2 to S5 (during discharging) and S6 to S9 (during charging) are performed once after the operation of the electrical network shown in Fig. 1 shows schematically a circuit diagram of the electrical network in which the invention is used; is started. Step S1 and decision El are then repeated, for example at a predefined sampling rate and therefore at a time interval of At. A discharge adaptation step or a charge adaptation step is then performed depending on the result. The following steps and decisions are additionally performed during discharging: - In decision E2, a check is carried out to determine whether at least one discharge adaptation step has or has not already been performed. - In decision E3, a check is carried out to determine whether at least one charge adaptation step has or has not already been performed. - In step S10, the regulator 1 checks whether the power consumption P of the consumer 2 has changed to such an extent since the last execution of a discharge adaptation step that the change meets a predefined discharge execution criterion EDK. This discharge execution criterion EDK is met, for example, if the percentage change or the absolute change in the power consumption P is above a predefined change limit. - Due to decision E4, the method is continued in either the "Yes" branch or the "No" branch, depending on the result of the check in step S10. If the power consumption P has changed substantially ("Yes" branch), step S3 is performed once more. - In step S11, the regulator 1 checks whether the operational state of at least one supply line has changed to such an extent since the last selection of the N supply lines that this change in an operational state meets a provided discharge execution criterion EDK(N). This discharge execution criterion EDK(N) can also be met if the absolute or percentage change in an operational state reaches a predefined limit or if the value of an operational parameter of the supply line lies outside a predefined range. Step S11 is performed in the embodiment even if step S10 has produced the result that the target number N_opt(P) remains unchanged. - Due to decision E5, the method is continued in either the "Yes" branch or the "No" branch, depending on the result of the check in step S11. - If an operating parameter has changed substantially ("Yes" branch), steps S4 and S5 are performed once more, i.e. N supply lines are selected once more and the DC voltage converters are controlled accordingly.

The following steps and decisions are additionally performed during charging: - In step S12, the regulator 1 checks whether the power P1 which the further voltage source 3, 4 can provide has changed substantially since the last charge adaptation step. The regulator 1 applies a predefined charge execution criterion BDK for this purpose. - A decision E6 is made depending on the result of the check in step S12. - If the power P1 has changed substantially, step S7 is performed once more. Otherwise, a check is carried out to determine whether the operational state of at least one supply line has changed substantially since the last discharge adaptation step (step S13). The regulator 1 applies a charge execution criterion EDK(M) for this purpose. Steps S8 and S9 are further performed according to the flow diagram, i.e. the supply lines to be charged are selected and the DC voltage converters are controlled accordingly.

The factors on which the discharge-selection criterion EAK depends are set out below, wherein the regulator 1 applies said criterion in order to select N supply lines VS.i(1), . .

, VS.i(N) in a step S3. As already explained, the regulator 1 then controls the DC voltage converters in step S4 in such a way that the DC voltage converters G.i(1), . . , G.i(N) of the N selected supply lines VS.i(1), . . , VS.i(N) are in a load state and the remaining DC voltage converters are in an idle state.

The discharge-selection criterion EAK can depend on the present states of charge of 1o the N_ges supply lines. In one design, in step S3, the regulator 1 selects those N supply lines whose voltage sources have the highest states of charge (SOC). In another design, the regulator 1 determines those supply lines whose states of charge lie above a limit that is predefined or is defined during operation, and performs the selection from these preselected supply lines on the basis of at least one additional criterion.

The additional criterion may, for example, be the current operating temperatures of the supply lines. The regulator 1 selects those N supply lines with the lowest operating temperatures from the preselected supply lines, i.e. those supply lines whose voltage sources and/or whose DC voltage converters currently have the lowest operating temperatures. A different criterion may, for example, be the number of hitherto performed charging procedures and discharging procedures for the voltage sources. The respective battery management system MS.i of a supply line VS.i is capable of providing these numbers.

The additional criterion may also depend on the positionings of the supply lines. Supply lines are activated, for example, in such a way that the magnetic fields produced by them at least partially mutually compensate one another and do not increase.

The charge-selection criterion BAK can depend on the present states of charge of the Nges supply lines. In one design, in step S3, the regulator 1 selects those M supply lines whose voltage sources have the lowest states of charge.

Fig. 3 shows two examples of U-I characteristics for a DC voltage converter; shows, by way of example, a resulting U-I characteristic for the electrical network from Fig. 1 shows schematically a circuit diagram of the electrical network in which the invention is used; , wherein the regulator 1 applies the invention. The operating point BP is changed compared with the operating point from Fig. 1 shows schematically a circuit diagram of the electrical network in which the invention is used; , i.e. to Iout = 326 A and U_out = 495 V. In the situations shown, step S3 produces the result N-opt(P) = 6. The N= 6 selected supply lines VS.i(1), . . , VS.i(6) are equally loaded, i.e. with Iout(i(1)) = ... = Iout(i(6)) = 326/6 ~ 54.3 A.

Fig. 4 shows an example of a flow diagram for carrying out the method; shows a detail enlargement from Fig. 3 shows two examples of U-I characteristics for a DC voltage converter; and, by way of example, the U-I characteristics from the two DC voltage converters G.1 and G.7. In the example shown in Fig. 3shows two examples of U-I characteristics for a DC voltage converter; and Fig. 4 shows an example of a flow diagram for carrying out the method; ,the supply line VS.1 is associated with the N = 6 selected supply lines and the supply line VS.7 is associated with the N_ges - N = 22 - 6 = 16 non-selected supply lines. The DC voltage converter G.1 of the selected supply line VS.1 is therefore operated in a load state and the DC voltage converter G.7 of the non-selected supply line VS.7 is operated in an idle state. Fig. 4 shows an example of a flow diagram for carrying out the method; shows the two U-I characteristics U-.L(1) and U-I.R(7) of the two voltage converters G.1 and G.7. The U-I characteristic U-.L(1) results in a load state, the U-I characteristic U-.R(7) in an idle state. In this example, the DC voltage converters of the non-selected supply lines are not loaded (I_out = 0 A). The two operating points BP(1) of the DC voltage converter G.1 and BP(7) of the DC voltage converter G.7 are plotted in Fig. 4 shows an example of a flow diagram for carrying out the method;

The charging of the N_ges voltage sources is illustrated in Fig. 5 shows schematically the dependence of the current intensity on the voltage in an application in which the invention is used; . The current density assumes a negative value. The operating point shown is at Iout= -278 A and U-out = 535.5 V. M = 6 supply lines are selected, including the supply line VS.7. The DC voltage converters of the selected M supply lines VS.j(1), . . , VS.j(6) are operated in the load state. The current intensities Iout(j(1)) = . . = Iout(j(6)) are -278 A/6 ~ -46.3 A. The current intensities of the remaining DC voltage converters are 0 A (idle state).

In the exemplary embodiment, an emergency operation is provided for the case where the regulator 1 has failed or is no longer connected to the battery management system MS.1,..., MS.Nges and therefore a higher-level regulation is no longer possible. In this case, each DC voltage converter G.1, . . , G.Nges operates according to a default U-I characteristic. This default U-I characteristic results, for example, from the variable U-I characteristic shown in Fig. 1 shows schematically a circuit diagram of the electrical network in which the invention is used; , wherein the characteristic parameter assumes a predefined default value. It is also possible for the battery management system MS.i of each supply line VS.i to determine the present state of charge SOC(i) and to derive a value for the characteristic parameter from the present state of charge SOC(i) and predefine said value for the DC voltage converter G.i.

Reference numbers 1 Regulator, receives signals from the battery management systems MS.1, .. MS.Nges, controls the DC voltage converters G.1, . . , G.Nges 2 Electrical consumer, is supplied with current at the current intensity lout and the voltage U_out 3 Further voltage source in the form of the fuel cell system, is capable of charging the voltage sources of the supply lines VS.1, . . , VS.Nges via the DC voltage converter G 4 Further voltage source in the form of a generator, is capable of supplying the consumer 2 directly and charging the voltage sources of the supply lines VS.1, . . , VS.Nges B.i.1, Series-connected batteries of the supply line VS.i, together form the voltage . . ,Isource Sq.i of this supply line VS.i B.i.Z El Decision following step S1 concerning whether the N ges voltage sources Sq.1, . . , Sq.N_ges are intended to supply the consumer 2 or to be charged E2 Decision concerning whether a discharge adaptation step has already been performed E3 Decision concerning whether a charge adaptation step has already been performed E4 Decision following step S10 concerning whether the power consumption P has changed substantially E5 Decision concerning whether the discharge execution criterion EDK(N) is met E6 Decision concerning whether the power P1 which the further voltage source 3 can provide has changed substantially E7 Decision concerning whether the charge execution criterion BDK(M) is met EAK Discharge-selection criterion for selecting N supply lines EAZ Discharge-number relationship for determining the optimum target number N_opt(P) EDK Discharge execution criterion for deciding whether a discharge-selection step is performed once more EDK(N) Discharge execution criterion for deciding whether N supply lines are selected once more G Unidirectional DC voltage converter between the further voltage source 3 and the consumer 2 G.i Bidirectional DC voltage converter of the supply line VS.i, arranged between the voltage source Sq.i and the consumer 2 I_in(i) Input-side current intensity of the DC voltage converter G.i I_out(i) Output-side current intensity of the DC voltage converter G.i M Number of supply lines selected in a charge adaptation step. The DC voltage converters of these M selected supply lines VS.j(1), . . , VS.j(N) are operated in a load state N Number of supply lines selected in a discharge adaptation step, where N >= N_opt(P). The DC voltage converters of these N selected supply lines VS.i(1), . . , VS.i(N) are operated in a load state N_ges Number of parallel-connected supply lines of the network N_opt( Target number of active supply lines depending on the power consumption P) P of the consumer 2 P Present power consumption of the consumer 2 P1 Present possible power output of the further voltage source 3 Par.L Value which the characteristic parameter assumes in the case of the U-I characteristic U-I.L(i) Par.R Value which the characteristic parameter assumes in the case of the U-I characteristic U-I.R(i) S1 Step: checking whether the N-ges voltage sources Sq.1, . . , Sq.Nges are intended to supply the consumer 2 or to be charged S2 Step: determining the present electrical power consumption P by the consumer 2 S3 Step: determining the optimum target number N-opt of simultaneously active supply lines S4 Step: selecting N supply lines, N >= N_opt

S5 Step: controlling the N_ges DC voltage converters in such a way that the DC voltage converters of the selected N supply lines are in a load state S6 Step: determining the power P1 which the further voltage source 3 can presently output S7 Step: defining the optimum target number M_opt(P1) of voltage sources to be simultaneously charged S8 Step: selecting M supply lines whose voltage sources are intended to be charged S9 Step: controlling the N_ges DC voltage converters in such a way that the DC voltage converters of the selected M supply lines are in an idle state S10 Step: checking whether the power consumption P of the consumer 2 has changed substantially S1l Step: checking whether the operational state of a supply line has changed substantially S12 Step: checking whether the power P1 which the further voltage source 3 can provide has changed substantially S13 Step: checking whether the operational state of at least one supply line has changed substantially SOC(i) State of charge of the voltage source Sq.i Sq.i Voltage source of the supply line VS.i, comprises the batteries B.i.1, B.i.Z, connected to the DC voltage converter G.i U-I.L(i) U-I characteristic of the voltage converter G.i for a load state U-I.R(i) U-I characteristic of the voltage converter G.i for an idle state U_out Voltage applied to the consumer 2, is normally also applied to the outputs of all DC voltage converters G.1, . . , G.Nges. U_out(i Voltage applied to the output of the DC voltage converter G.i, is normally ) equal to the voltage U_out applied to the consumer 2 VS.i Supply line, comprises a voltage source Sq.i, a battery management system MS.i and a DC voltage converter G.i

Claims (22)

Patent claims

1. A method for automatically regulating an electrical network on board of an underwater vehicle, wherein the network comprises: - an electrical consumer (2), - N-ges parallel-arranged supply lines (VS.1, . . , VS.Nges), and - a signal-processing regulator (1),

where N_ges is greater than or equal to 2, wherein each supply line (VS.1, . . , VS.N_ges) in each case comprises: - a voltage source (Sq.1, . . , Sq.Nges), and - a voltage converter (G.1, . . , G.N_ges), and

wherein the voltage source (Sq.1, . . , Sq.N_ges) of a supply line (VS.1, VS.Nges) is electrically connected via the voltage converter (G.1, . . , G.Nges) of this supply line (VS.1, . . , VS.N_ges) to the consumer (2), and wherein the consumer (2) is supplied with electrical current and receives electrical power, characterized in that the respective voltage converter (G.1, . . , G.N_ges) of each supply line (VS.1, VS.Nges) is operable in either at least one load state or at least one idle state, wherein a discharge adaptation step is performed at least once automatically, said discharge adaptation step comprising the steps in which the regulator (1): - selects N supply lines (VS.i(1), . . , VS.i(N)) from the N_ges supply lines (VS.1, .. VS.Nges) of the network depending on the present power consumption P of the consumer (2), and - controls the voltage converters (G.1, . . , G.Nges) of the N_ges supply lines (VS.1, ., VS.Nges) of the network in such a way that the voltage converters (G.i(1),..., G.i(N)) of the N selected supply lines (VS.i(1), . . , VS.i(N)) are in each case in a load state and the voltage converters of the remaining supply lines are in each case in an idle state, wherein the consumer (2) is supplied with electrical current from the N voltage sources (Sq.i(1), . . , Sq.i(N)) of the N selected supply lines (VS.i(1), . . , VS.i(N)), and wherein at least one non-selected supply line of the N_ges supply lines (VS.1, VS.Nges) of the network remains electrically connected to the consumer (2).

2. The method as claimed in claim 1, characterized in that during the discharge adaptation step, the regulator (1) performs the selection of the N supply lines (VS.i(1), . . , VS.i(N)): - depending on the present power consumption P, and - additionally depending on the present states of the N_ges supply lines (VS.1, VS.Nges) of the network.

3. The method as claimed in claim 2, characterized in that an automatically evaluable discharge-number relationship (EAZ) is predefined which in each case defines a target number N_opt = N_opt(P) of simultaneously active supply lines of the network for a multiplicity of possible values for the power consumption P of the consumer (2), and a discharge-selection criterion (EAK) depending on the states of the N_ges supply lines (VS.1, . . , VS.Nges) of the network is predefined, wherein the step in which the regulator (1) selects N supply lines (VS.i(1), VS.i(N)) comprises the steps in which the regulator (1): - determines a target number N_opt(P) which the predefined discharge-number relationship (EAZ) assigns to the present power consumption P of the consumer (2), and - performs the selection of the N supply lines (VS.i(1), . . , VS.i(N)) depending on the states of the N_ges supply lines (VS.1, . . , VS.Nges) by applying the predefined discharge-selection criterion (EAK), where N is greater than or equal to N_opt(P).

4. The method as claimed in claim 2 or claim 3, characterized in that an automatically evaluable power output relationship is predefined which in each case defines a target total nominal power P_opt(P) of the electrical power to be supplied in total by the N_ges supply lines (VS.1, . . , VS.Nges) for a multiplicity of possible values for the power consumption P of the consumer, a discharge-selection criterion (EAK) depending on the states of the N_ges supply lines (VS.1, . . , VS.Nges) of the network is defined, wherein the step in which the regulator (1) selects the N supply lines (VS.i(1), VS.i(N)) comprises the steps in which the regulator (1): - determines a target total nominal power P_opt(P) which the power output relationship assigns to the present power consumption P of the consumer (2), and - selects the N supply lines (VS.i(1), . . , VS.i(N)) by applying the predefined discharge-selection criterion depending on the states of the N_ges supply lines (VS.1, ... , VS.Nges) in such a way that these selected supply lines together provide at least the target total nominal power P_opt(P).

5. The method as claimed in one of claims 2 to 4, characterized in that the regulator (1) performs the selection of the N supply lines (VS.i(1), . . , VS.i(N)) depending on: - the states of charge (SOC(1), . . , SOC(Nges)) of the N_ges voltage sources (Sq.1, . . , Sq.Nges), - the current temperatures (Temp(1), . . , Temp(Nges)) of the N_ges voltage sources (Sq.1, . . , Sq.Nges), - the current temperatures of the voltage converters (G.1, . . , G.Nges), - the numbers (Anz(1), . . , Anz(Nges)) of respectively hitherto performed charging procedures and/or discharging procedures for the N_ges voltage sources (Sq.1, . . , Sq.Nges), and/or - the spatial positionings of the N_ges supply lines (VS.1, . . , VS.N_ges).

6. The method as claimed in claim 5, characterized in that the regulator (1) selects those N supply lines (VS.i(1), . . , VS.i(N)) whose voltage sources (Sq.i(1), . . , Sq.i(N)) have the highest states of charge at the time of the selection.

7. The method as claimed in one of the preceding claims, characterized in that the regulator (1): - automatically monitors whether the power consumption P of the consumer (2) has changed since the last discharge adaptation step in such a way that a predefined discharge execution criterion (EDK) is met, and - performs a discharge adaptation step once more at least in the case where the change in the power consumption meets the discharge execution criterion (EDK).

8. The method as claimed in one of the preceding claims, characterized in that the regulator (1): - automatically monitors whether an operational state of a supply line (VS.1, VS.Nges) has changed since the last discharge adaptation step in such a way that a predefined selection execution criterion (EDK(N)) is met, and - at least in the case where the change in at least one operational state meets the predefined selection criterion (EDK(N)), once more performs the steps of selecting N supply lines (VS.i(1), . . , VS.i(N)) and of switching the voltage converters (G.i(1), . . , G.i(N)) of the N selected supply lines (VS.i(1), . . , VS.i(N)) in each case to a load state.

9. The method as claimed in claim 7 or claim 8, characterized in that the selection of the N supply lines (VS.i(1), . . , VS.i(N)) remains unchanged as long as the regulator (1) has established that the change in the power consumption (P) and/or the change in the operational states does not meet the respective execution criterion (EDK, EDK(N)).

10.The method as claimed in one of the preceding claims, characterized in that at least once, in response to the event in which, following a discharge adaptation step, the power consumption P of the consumer (2) has increased, the steps are performed in which: - at least one of the currently non-selected N_ges - N supply lines is selected, - the voltage converter of the or of each additionally selected supply line is switched to the or a load state, and - the regulator (1) then performs a discharge adaptation step once more.

11.The method as claimed in one of the preceding claims, characterized in that at least one load U-1 relationship (U-I.L(i)) and at least one idle U-I relationship (U I.R(i)) are predefined for each voltage converter (G.i), wherein each U-I relationship defines a current intensity (Iout(i)) to be supplied by the voltage converter (G.i) depending on the value of the applied voltage (Uout), wherein the load U-I relationship (U-I.L(i)) produces a higher value for the current intensity to be supplied than the idle U-1 relationship (U-I.R(i)) at least in a value range for the voltage applied to the voltage converter (G.i) in the case of an equal value for the applied voltage, wherein the step in which the regulator (1) controls a voltage converter (G.i) in such a way that the voltage converter (G.i) is in a load state causes the voltage converter (G.i) to operate according to the or a load U-1 relationship (U-.L(i)), and wherein the step in which the regulator controls a voltage converter (G.i) in such a way that the voltage converter (G.i) is in an idle state causes the voltage converter (G.i) to operate according to the or an idle U-1 relationship (U-.R(i)).

12.The method as claimed in one of the preceding claims, characterized in that for each voltage converter (G.i), a U-I characteristic is predefined in each case which: - defines the current intensity (Iout(i)) to be supplied by the voltage converter (G.i) depending on the applied voltage (Uout), and - depends on a variable characteristic parameter,

wherein, at least in a value range for the voltage (Uout) applied to the voltage converter (G.i) in the case of an equal value for the applied voltage, the greater the characteristic parameter, the greater the value for the current intensity (Iout(i)) defined by the U-I characteristic, wherein the step of transferring a voltage converter (G.i) from an idle state into a load state comprises the step of increasing the characteristic parameter of this voltage converter (G.i), and wherein the step of transferring a voltage converter (G.i) from a load state into an idle state comprises the step of reducing the characteristic parameter of this voltage converter (G.i).

13.The method as claimed in one of the preceding claims, characterized in that at least one supply line (VS.1, . . , VS.Nges) is disconnected at least once from the consumer (2), and the regulator (1) performs a discharge adaptation step once more in response to the disconnection, wherein the or each disconnected supply line is not selected.

14.The method as claimed in one of the preceding claims, characterized in that each supply line (VS.1, . . , VS.N_ges) is connected or is temporarily connected to at least one further voltage source (3, 4), wherein each voltage source (Sq.1, . . , Sq.Nges) of the network can either: - output electrical energy to the consumer (2), or

- receive and store electrical energy from the further voltage source (3, 4),

wherein a charge adaptation step is performed at least once in which: - the regulator (1) selects M supply lines (VS.j(1), . . , VS.j(M)), and - the voltage sources (Sq.j(1), . . , Sq.j(M)) of the selected M supply lines (VS.j(1), ... , VS.j(M)) are charged from the further voltage source (3, 4).

15.The method as claimed in claim 14, characterized in that the charge adaptation step comprises the additional steps in which: - the regulator (1) controls the voltage converters (G.1, . . , G.Nges) in such a way that at least the voltage converters (G.j(1), . . , G.j(M)) of the selected M supply lines (VS.j(1), . . , VS.j(M)) are in the or a load state, and - the voltage sources (Sq.j(1), . . , Sq.j(M)) of the selected M supply lines (VS.j(1), .. VS.j(M)) are charged from the further voltage source (3, 4) using the voltage converters (G.j(1), . . , G.j(M)) in the load state of the selected M supply lines (VS.j(1), . . , VS.j(M)).

16. The method as claimed in claim 14 or claim 15, characterized in that at least one charge adaptation step comprises the steps in which: - the regulator (1) determines a target number M-opt of voltage sources to be charged, and - the regulator (1), when selecting the M supply lines (VS.j(1), . . , VS.j(M)) to be charged, applies a predefined charge-selection criterion (BAK) depending on the states of the supply lines (VS.1, . . , VS.Nges) of the network, where M is less than or equal to M_opt.

17.The method as claimed in claim 16, characterized in that the target number M_opt depends on a power parameter of the further voltage source (3).

18. The method as claimed in claim 16 or claim 17, characterized in that the charge-selection criterion (BAK) depends on: - the states of charge (SOC(1), . . , SOC(Nges)) of the voltage sources (Sq.1, Sq.N_ges), - the current temperatures (Temp(1), . . , Temp(Nges)) of the voltage sources (Sq.1, . . , Sq.Nges), - the current temperatures of the voltage converters (G.1, . . , G.Nges), - the numbers (Anz(1), . . , Anz(Nges)) of respectively hitherto performed charging procedures and/or discharging procedures for the voltage sources (Sq.1, . . , Sq.Nges), and/or - the spatial positionings of the supply lines (VS.1, . . , VS.Nges).

19. The method as claimed in one of claims 14 to 18, characterized in that the regulator (1), if a supply line is associated at the same time: - not only with the N supply lines (VS.i(1),..., VS.i(N)) selected for the electrical supply of the consumer (2), - but also with the M supply lines (VS.j(1),..., VS.j(M)) selected for charging,

decides automatically: - either to control the voltage converter of this supply line in such a way that it is in the load state, and to select a different supply line for charging, - or to control the voltage converter of this supply line in such a way that it is in the idle state, and to control the voltage converter of a different supply line in such a way that it is transferred from the idle state into the load state.

20.The method as claimed in one of the preceding claims, characterized in that the voltage converter (G.1, . . , G.Nges) of a supply line (VS.1, . . , VS.Nges) comprises:

- a plurality of switching elements, and - a control unit for controlling these switching elements,

wherein the control unit is supplied with electrical current even if the voltage converter (G.1, . . , G.N_ges) is in the or an idle state.

21.An underwater vehicle having an electrical network, wherein the network comprises: - an electrical consumer (2), - N-ges parallel-arranged supply lines (VS.1, . . , VS.Nges), and - a signal-processing regulator (1),

where N_ges is greater than or equal to 2, wherein each supply line (VS.1, . . , VS.N_ges): - is electrically connected to the consumer (2), - in each case comprises a voltage source (Sq.1, . . , Sq.N_ges) and a voltage converter (G.1, . . , G.Nges), and - is designed to contribute to the supply of the consumer (2) with electrical current, and

wherein the consumer (2) is designed to receive electrical power, characterized in that at least one voltage converter (G.1, . . , G.Nges) of each supply line (VS.1, VS.Nges) is operable in each case in either at least one load state or at least one idle state, wherein the regulator (1) is designed to perform a discharge adaptation step which comprises the steps in which the regulator (1): - selects N supply lines (VS.i(1), . . , VS.i(N)) from the N_ges supply lines (VS.1, .. VS.Nges) of the network depending on the present power consumption P of the consumer (2), and - controls the voltage converters (G.1, . . , G.Nges) of the N_ges supply lines (VS.1,..., VS.Nges) of the network in such a way that the voltage converters (G.i(1),..., G.i(N)) of the N selected supply lines (VS.i(1), . . , VS.i(N)) are in each case in a load state and the voltage converters of the remaining supply lines are in each case in an idle state, wherein the network is designed so that the N voltage sources (Sq.i(1), . . , Sq.i(N)) of the N selected supply lines (VS.i(1), . . , VS.i(N)) supply the consumer (2) with electrical current, and wherein all N_ges supply lines (VS.1, . . , VS.Nges) of the network are connected at least temporarily to the consumer (2).

22.The underwater vehicle as claimed in claim 21, 1o characterized in that the regulator (1) has read access at least temporarily: - to an automatically evaluable discharge-number relationship (EAZ), and - to a discharge-selection criterion (EAK) depending on the states of the N_ges supply lines (VS.1, . . , VS.N_ges) of the network,

wherein the discharge-number relationship (EAZ) in each case defines a target number N_opt = N_opt(P) of simultaneously active supply lines of the network for a multiplicity of possible values for the power consumption P of the consumer (2), and wherein, during the step of selecting N supply lines (VS.i(1), . . , VS.i(N)), the regulator (1) is designed to perform the following steps: - determining a target number N_opt(P) which the discharge-number relationship assigns (EAZ) to the present power consumption P of the consumer (2), and - performing the selection of the N supply lines (VS.i(1), . . , VS.i(N)) by applying the discharge-selection criterion (EAK), where N is greater than or equal to N-opt(P).