Boat with electric drive

Abstract

A method for charging an auxiliary voltage source of a boat having an electric drive that is powered by a main voltage source of the boat, the auxiliary voltage source providing power for at least one additional component, is described. A protection and/or control circuit is electrically connected to the main voltage source via a DC-to-DC converter configured for power supply, and to the auxiliary voltage source via a switch or a reverse blocking valve. The auxiliary voltage source is charged via the main voltage source.

Claims

1. A method for charging an auxiliary voltage source of a boat having an electric drive that is powered by a main voltage source of the boat, the auxiliary voltage source providing power for at least one additional component, the method comprising: electrically connecting a protection and/or control circuit to the main voltage source via a DC-to-DC converter configured for power supply, and to the auxiliary voltage source via a reverse blocking valve; electrically connecting the main voltage source to the auxiliary voltage source via a charging device; and charging the auxiliary voltage source via the main voltage source.

2. The method of claim 1, wherein the main voltage source has a terminal voltage of more than 60 V, and the auxiliary voltage source has a terminal voltage of at most 48 V.

3. The method of claim 1, further comprising charging the main voltage source and the auxiliary voltage source at different times.

4. The method of claim 1, the method further comprising: supplying, via the auxiliary voltage source, a current to the protection and/or control circuit, and to the charging device.

5. The method of claim 1, wherein the auxiliary voltage source is a low-voltage source that has a charge of at least 30 Ah.

6. The method of claim 1, wherein the reverse-blocking valve comprises a diode.

7. The method of claim 1, wherein the reverse-blocking valve comprises a MOSFET driven in the inverse direction.

8. The method of claim 1, wherein the reverse-blocking valve comprises a MOSFET based circuit in which the MOSFET channel is switched on in the conducting state such that forward losses are reduced.

9. An electrical system for a boat, the system comprising: a main voltage source that is electrically connectable to an electric drive so as to provide power to the electric drive; an auxiliary voltage source that is electrically connected to and powers at least one additional component of the boat; a charging device electrically connecting the main voltage source to the auxiliary voltage source, wherein the auxiliary voltage source is configured to be charged by the main voltage source via the charging device; and a control circuit that is electrically connected to the main voltage source via a DC-to-DC converter, and to the auxiliary voltage source via a reverse blocking valve, the control circuit being operable to electrically connect and disconnect the main voltage source from at least the electric drive.

10. The system of claim 9, wherein the main voltage source and the auxiliary voltage source are configured to be charged at different times.

11. The system of claim 9, wherein the auxiliary voltage source is configured to supply a current to the control circuit, and to the charging device.

12. The system of claim 9, wherein the auxiliary voltage source is a low-voltage source that has a charge of at least 30 Ah.

13. The system of claim 9, wherein the reverse-blocking valve comprises a diode.

14. The system of claim 9, wherein the reverse-blocking valve comprises a MOSFET driven in the inverse direction.

15. The system of claim 9, wherein the reverse-blocking valve comprises a MOSFET based circuit in which the MOSFET channel is switched on in the conducting state such that forward losses are reduced.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows a power supply according to embodiments of the invention on a boat, and

(2) FIG. 2 shows a further embodiment.

DETAILED DESCRIPTION OF THE DRAWINGS

(3) A boat with an electric drive 1 has a high-voltage source 2 to which the electric drive 1 is connected. The high-voltage source 2 is a rechargeable lithium-ion battery which has a maximum charge of, for example, 80 Ah, 100 Ah, 150 Ah or 200 Ah and a nominal voltage of more than 200 V, for example 300 V, 350 V or 400 V. Further power consumers may likewise be connected to the supply line 3 which is connected to the high-voltage source 2.

(4) The high-voltage source 2 can be charged via a main charging device 4 found on the boat and connected to the supply line 3. In order to charge the high-voltage source 2, the main charging device 4 is connected to a power supply which is not illustrated in the figure and which is located outside of the boat, for example on land. The interface between the electrical systems on the boat and those on land is marked by the reference sign 7.

(5) A low-voltage source 5 is also provided on the boat, said low-voltage source having a terminal voltage of, for example, 12 V, 24 V or 48 V. Several electrical components which are used for the comfort of the boat's crew and safety-related components, such as control devices, a navigation system and, in particular, a safety circuit which connects the high-voltage source 2 to the supply line 3 or disconnects it therefrom, are connected to the low-voltage source 5.

(6) According to embodiments of the invention, an auxiliary charging device 6 is provided on board and connected to the supply line 3. The auxiliary charging device 6 comprises a DC-to-DC converter and enables the charging of the low-voltage source 5 from the high-voltage source 2.

(7) FIG. 2 shows another embodiment of the circuit according to the invention. Identical components in the two figures are provided with identical reference signs.

(8) The circuit composed of electric motor 1, high-voltage source 2, main charging device 4, low-voltage source 5 and auxiliary charging device 6 corresponds to the circuit according to FIG. 1.

(9) Additional components 8, for instance lighting or consumer electronics, and safety-related components 9 are connected to the low-voltage source 5. In FIG. 2, by way of example, a safety circuit is provided for a safety-related component 9, which safety circuit opens the switch 12 if necessary and thus switches the connection terminals of the high-voltage source 2 to be isolated from the supply.

(10) The additional components 8 are directly connected to the low-voltage source 5 and are supplied with power therefrom. According to embodiments of the invention, an auxiliary charging device 6 is provided on board and is connected to the supply line 3. The auxiliary charging device 6 comprises a DC-to-DC converter and enables the charging of the low-voltage source 5 from the high-voltage source 2.

(11) In the embodiment according to FIG. 2, the low-voltage source 5 is also used to supply the additional components 9. In this case, it is expedient to provide an electrical decoupling of the power supply of the additional components and the power supply of the system components and safety-related components.

(12) The safety-related components 9 are supplied with power via a further DC-to-DC converter 10, which is connected to the supply line 3.

(13) A reverse-blocking valve 11, for example a diode, is used for electrical decoupling. A DC-to-DC converter 10 is used for the electrical power supply of the safety-related components, which DC-to-DC converter provides the low voltage for the safety-related components from the high-voltage source 2.

(14) The safety-related components 9 are hence decoupled from the rest of the additional components 8 and supplied in a manner decoupled from the low-voltage source 5. If a temporary overloading of the low-voltage source 5 by connected additional components 8 were to occur, the operation of the safety-related controllers 9 would not be impaired since said controllers 9 have their own supply 10 and are decoupled from the low-voltage source 5 by the reverse-blocking valve 11.

(15) In the simplest case, the reverse-blocking valve 11 can be a diode. In order to reduce the forward losses, the diode can be replaced by an inversely driven MOSFET, the channel of which is additionally switched on when current flows via the inverse diode.

(16) A reliable supply to the additional components 8 with pulse-shaped power demands is ensured by the connection of the primary low-voltage circuit to the low-voltage source 5. The operation of an auxiliary motor for trimming and/or tilting of an outboard motor is a typical pulse load of this type, which must be buffered by the low-voltage source 5.