Motor vehicle with a starter generator

Abstract

Motor vehicle (1) with a first energy storage device (ES1) for storing electrical energy, with a second energy storage device (ES2) for storing electrical energy, and with a starter-generator (SG) for starting an internal combustion engine (M) of the motor vehicle (1) or with a generator and a starter for starting an internal combustion engine (M) of the motor vehicle (1), wherein the first energy storage device (ES1) and the second energy storage device (ES2) are electrically connected to the starter-generator (SG) or the generator in such a way that the first energy storage device (ES1) and the second energy storage device (ES2) can be charged by means of the starter-generator (SG) or the generator, wherein the second energy storage device (ES2) is electrically connected to the starter-generator (SG) or the generator and / or starter by means of a switch-diode arrangement (S1), wherein a diode (D) is advantageously connected in parallel with the switch-diode arrangement (S1),wherein the switch-diode arrangement (S1) comprises a temperature sensor (T) arranged at the negative pole of the switch-diode arrangement (S1), and wherein the switch-diode arrangement (S1) is designed to output diagnostic data relating to the first energy store (ES1) and / or comprises a bus interface, in particular a CAN bus interface.

Description

[0001] The invention relates to a motor vehicle with an energy storage device for storing electrical energy and with a starter generator for starting an internal combustion engine of the motor vehicle.

[0002] DE 102 28 350 A1 discloses an on-board power supply system for supplying a high-power consumer with a generator, with a first energy storage device connected to the generator via the on-board power supply system and with a plurality of consumers connected to the on-board power supply system, of which at least one is a high-power consumer, wherein the high-power consumer is connected to a second energy storage device which is connected to the on-board power supply system via a controllable charging and disconnecting unit.

[0003] DE 10 2008 054 885 A1 discloses a device for controlling a power supply of an on-board electrical system of a vehicle to which consumers can be connected, wherein a first energy store for providing electrical energy to a starter, a generator for generating a generator voltage and a controllable switching element are provided which is arranged between the first energy store and the generator and which is designed such that, during operation of the vehicle, it allows a current flow in only one direction from the first energy store to the generator.

[0004] DE 10 2009 043 878 A1 discloses a method for the short-term supportive energy supply of an on-board energy storage device such as a rechargeable battery or battery of a vehicle electrical system during a short-term load of the on-board electrical system by starting an engine, wherein a capacitor is connected in parallel or in series to the on-board energy storage device by means of at least one switching element when the on-board energy storage device is loaded.

[0005] DE 10 2005 018 620 A1 discloses a power supply circuit for starting a vehicle engine with a plurality of double-layer capacitors connected in series to form an energy storage device, with first means for switching the energy storage device over or on to a battery of a supply network for the engine and with a connection to a control node which is functionally connected to the battery of the network, wherein when the energy storage device is intentionally switched on, the first means and the battery relay are switched and the stored energy of the energy storage device is available to the supply network until the second means interrupts the holding branch of the first means due to an intentional switching off of the energy storage device.

[0006] EP 0 945 959 A2 discloses a device for supplying voltage in a motor vehicle, having an on-board electrical system which comprises at least two batteries which can be connected to one another via an electrical circuit which comprises at least one series connection of a relay and a semiconductor switch, wherein the connection point between the relay and the semiconductor switch leads to a terminal via which start-relevant electrical consumers are supplied with voltage, wherein the relay is a relay with only one make contact and the relay is controlled in such a way that it is energised in the normal operating state and in the process establishes a conductive connection between the supply battery and the start-relevant consumers.

[0007] DE 10 2007 062 955 A1 discloses a circuit for voltage stabilization of an on-board electrical system, particularly for motor vehicles, which is arranged in electrical connection between the on-board electrical system to be stabilized and a first energy storage device. The circuit comprises a diode element containing several semiconductor switches connected in parallel, a monitoring and control circuit that determines the strength of a current flowing through the diode element and controls the semiconductor switches of the diode element according to the determined current strength, and a second energy storage device electrically connected to the diode element and the on-board electrical system.

[0008] DE 10 2004 007 851 A1 discloses a connection device for a vehicle battery, which serves to electrically connect a battery terminal to at least one electrical conductor. The connection device comprises a current measuring module with at least one measuring resistor and a measuring circuit that measures at least the voltage applied to the associated measuring resistor.

[0009] DE 10 2007 061 112 A1 discloses a sensor arrangement for detecting the condition of a battery in a motor vehicle. The sensor arrangement is arranged near the battery terminals to detect the electrical state variables of the battery. The sensor arrangement is equipped with sensors for the electrical state variables current, voltage, and temperature in the area of the battery of the sensor arrangement. Furthermore, storage means are provided for storing the course of the current, voltage, and temperature values during the engine start of the motor vehicle.

[0010] DE 10 2007 061 113 A1 discloses a sensor arrangement for detecting the condition of a battery in a motor vehicle. The sensor arrangement is arranged near the battery terminals to detect the battery's electrical state variables. The sensor arrangement is mounted on the negative battery terminal with a terminal. This terminal has a screw connection via which a ground cable can be connected to the vehicle's ground connection by means of a screwable screw.

[0011] Other on-board power systems are known, for example, from DE 199 55 721 A1, US 2005 / 0275289 A1 and DE 196 45 944 A1.

[0012] The object of the invention is to provide or specify an improved energy supply for a motor vehicle. In particular, an improved energy supply for a motor vehicle is to be specified in which the combustion engine can be switched off even while driving.

[0013] The above object is achieved by a motor vehicle with a first energy storage device for storing electrical energy, with a second energy storage device for storing electrical energy and - with a starter generator for starting a combustion engine of the motor vehicle or - with a generator and a starter for starting an internal combustion engine of the motor vehicle according to claim 1, wherein, among other things, it is provided that the first energy storage device and the second energy storage device are electrically connected to the starter-generator in such a way that the first energy storage device and the second energy storage device can be charged by means of the starter-generator, wherein the second energy storage device is electrically connected to the starter-generator by means of a switch-diode arrangement, wherein a diode is advantageously connected in parallel with the switch-diode arrangement, and wherein the switch-diode arrangement is designed to output diagnostic data relating to the first energy storage device and / or comprises a bus interface, in particular a CAN bus interface. It is also provided that the switch-diode arrangement comprises a temperature sensor arranged at the negative pole of the switch-diode arrangement.

[0014] An energy storage device within the meaning of the invention is, in particular, a rechargeable battery. An energy storage device within the meaning of the invention is, in particular, a lead-acid battery. An energy storage device within the meaning of the invention is, in particular, a lithium battery. An energy storage device within the meaning of the invention is, in particular, a power capacitor, in particular an ultracapacitor.

[0015] A starter generator within the meaning of the invention is, in particular, a belt starter generator. A starter generator within the meaning of the invention is, in particular, a crankshaft starter generator. A starter generator within the meaning of the invention is, in particular, an integrated starter generator. An integrated starter generator within the meaning of the invention is, in particular, arranged between the combustion engine and the transmission, in particular without an additional clutch. A starter generator within the meaning of the invention is, in particular, designed for an on-board electrical system operating voltage of at least 12 volts. A starter generator within the meaning of the invention is, in particular, designed for an on-board electrical system operating voltage of no more than 60 volts. A starter generator within the meaning of the invention is, in particular, designed for an operating voltage of (approximately) 12 volts.A starter generator within the meaning of the invention is designed in particular for an on-board electrical system operating voltage and / or for all voltage ranges below the high-voltage range defined according to ECE R100 up to 60V DC and 30V AC. A starter generator within the meaning of the invention is in particular mechanically coupled to the internal combustion engine of the motor vehicle. A starter generator within the meaning of the invention can be operated as a generator and as a motor for starting the internal combustion engine. In generator mode, a starter generator within the meaning of the invention is driven in particular by the internal combustion engine. A starter generator or a belt starter generator within the meaning of the invention can be obtained in particular from Bosch.

[0016] An internal combustion engine within the meaning of the invention can be, for example, a diesel engine or a gasoline engine. A diode within the meaning of the invention is designed, in particular, for a power output of no more than 100 watts.

[0017] A switch-diode arrangement within the meaning of the invention is, in particular, a MOSFET. A switch-diode arrangement within the meaning of the invention is, in particular, a field-effect transistor. A switch-diode arrangement within the meaning of the invention is, in particular, a transistor. A switch-diode arrangement within the meaning of the invention is, in particular, a power transistor.

[0018] A switch-diode arrangement within the meaning of the invention is, in particular, a quasidiode (Q-diode). A switch-diode arrangement within the meaning of the invention is, in particular, a semiconductor or a power semiconductor component whose equivalent circuit comprises a switch and a diode. The switch and the diode are connected in parallel. In an advantageous embodiment of the invention, the forward direction of the diode in the equivalent circuit is directed from the starter-generator to the second energy storage device.

[0019] For the purposes of the invention, diagnostic data relating to an energy storage device are in particular the internal resistance of the energy storage device, the capacity of the energy storage device, the state of health of the energy storage device and / or the absorption capacity of the energy storage device.

[0020] In an advantageous embodiment of the invention, the switch-diode arrangement is mechanically connected directly to the positive pole of the first energy storage device. A switch-diode arrangement is mechanically connected directly to the positive pole of the first energy storage device in the sense of the invention, in particular, if - the switch-diode arrangement is not more than 1 cm away from the positive pole of the first energy storage device and / or from the first energy storage device, and / or - the switch-diode arrangement is screwed to the positive pole of the first energy storage device.

[0021] In a further advantageous embodiment of the invention, the switch-diode arrangement comprises a computing device with a temperature model. The temperature model serves, in particular, to determine or estimate the temperature or the internal temperature of the first energy storage device. Input variables for the temperature model can be, for example, a temperature measurement value determined by the temperature sensor, the current through the switch-diode arrangement, and / or the voltage of the first energy storage device (in particular measured via a measuring line to ground and the connection to the positive pole through the switch-diode arrangement).

[0022] In a further advantageous embodiment, the switch-diode arrangement or the computing device of the switch-diode arrangement comprises a diagnostic module for generating the diagnostic data, in particular as a function of a temperature measurement value of the temperature sensor, an estimated temperature of the first energy storage device (supported by a temperature model), the voltage of the first energy storage device (in particular measured via a measuring line to ground and the connection at the positive pole through the switch-diode arrangement), and / or the current through the switch-diode arrangement. A diagnostic module within the meaning of the invention can in particular comprise or be a battery model of the first energy storage device.

[0023] In a further advantageous embodiment of the invention, the forward direction of the switch-diode arrangement is directed from the starter generator to the second energy storage device when the switch is open.

[0024] In particular, it is provided that the ohmic resistance of the / a switch-diode arrangement (with the switch open) is smaller than the ohmic resistance of the diode. In particular, it is provided that the ohmic resistance of the / a switch-diode arrangement (with the switch open) is at least one order of magnitude smaller than the ohmic resistance of the diode. In particular, it is provided that the ohmic resistance of the diode is at least 10 times greater than the ohmic resistance of the / a switch-diode arrangement (with the switch open).

[0025] In a further advantageous embodiment of the invention, the forward direction of the diode is directed from the starter generator or generator and / or starter to the second energy storage device.

[0026] In a further advantageous embodiment of the invention, the first energy storage device is electrically connected directly to the starter-generator. In a further advantageous embodiment of the invention, the first energy storage device and the starter-generator are electrically connected in parallel.

[0027] In a further advantageous embodiment of the invention, the second energy storage device and a lighting system of the motor vehicle, a steering system of the motor vehicle, and / or a braking system of the motor vehicle are electrically connected in parallel. A braking system within the meaning of the invention comprises, in particular, an anti-lock braking system and / or an anti-skid control system. A braking system within the meaning of the invention comprises, in particular, a vehicle stabilization system (for example, ESP). In a further advantageous embodiment of the invention, the first energy storage device is electrically connected to the lighting system of the motor vehicle, to the steering system of the motor vehicle, and / or to the braking system of the motor vehicle by means of the first switch-diode arrangement.In a further advantageous embodiment of the invention, the starter-generator is electrically connected to the lighting system of the motor vehicle, to the steering system of the motor vehicle, and / or to the braking system of the motor vehicle by means of the first switch-diode arrangement. In a further advantageous embodiment of the invention, the first energy store is electrically connected to the lighting system of the motor vehicle, to the steering system of the motor vehicle, and / or to the braking system of the motor vehicle by means of the diode. In a further advantageous embodiment of the invention, the starter-generator or the generator and / or starter is electrically connected to the lighting system of the motor vehicle, to the steering system of the motor vehicle, and / or to the braking system of the motor vehicle by means of the diode.

[0028] Where two elements are described as being electrically directly connected to one another, this means in particular that this direct connection does not exist or does not exist only via ground.

[0029] Further advantages and details are evident from the following description of exemplary embodiments. These show: Fig. 1 an embodiment of a motor vehicle, Fig. 2 an embodiment of an on-board network for the motor vehicle according to Fig. 1, Fig. 3 an embodiment of a switch-diode arrangement according to Fig. 2 and Fig. 4 an embodiment of a diagnostic module in a switch-diode arrangement according to Fig. 2.

[0030] Fig. 1 shows an embodiment of a motor vehicle 1 with an internal combustion engine M, which is coupled to a starter generator SG by means of a mechanical coupling KP in such a way that the internal combustion engine can be driven and started by means of the starter generator in the sense of a starter, and that the starter generator can be driven by means of the internal combustion engine M in a function as a generator.

[0031] Fig. 2 shows an exemplary embodiment of a 12-volt on-board electrical system of motor vehicle 1. Reference symbol LT denotes the lighting or lighting technology of motor vehicle 1, LK the steering system of motor vehicle 1, and reference symbol BR the braking system of motor vehicle 1. The lighting LT of motor vehicle 1, the steering system LK of motor vehicle 1, and the braking system BR of motor vehicle 1 are connected in parallel, with reference symbol U_BN designating the voltage drop across this parallel connection. The on-board electrical system comprises an electrical energy store ES2 for supplying the lighting LT, the steering system LK, and the braking system BR, with the supply voltage provided by the electrical energy store ES2 being designated U_ES2. In addition, a further electrical energy store ES1 is provided, which supplies the supply voltage U_ES1.

[0032] The starter-generator SG is provided for charging the electrical energy storage units ES1 and ES2; in generator mode, it supplies the voltage U_Gen. In motor mode, the voltage U_Start drops across the starter-generator SG, whereby the starter-generator SG is supplied with electrical energy via the energy storage unit ES1. The starter-generator SG is electrically connected to the energy storage unit ES2 via a switch-diode arrangement S1 and a diode D connected in parallel. The diode D, together with the switch-diode arrangement S1, protects the consumer side (U_BN) of the vehicle electrical system, i.e., the braking system BR of motor vehicle 1, the lighting LT of motor vehicle 1, and the steering system LK of motor vehicle 1, from a voltage drop when the combustion engine M is restarted.During normal driving, i.e. when the combustion engine is running and the starter-generator SG is therefore functioning as a generator, the supply current for the consumer environment (U_BN), i.e. for the braking system BR of motor vehicle 1, for the lighting LT of motor vehicle 1 and for the steering LK of motor vehicle 1, and for charging the electrical energy storage device ES2 flows via the switch-diode arrangement S1, since its semiconductors have a resistance that is one order of magnitude lower than that of diode D. The switch-diode arrangement S1 is screwed to the positive terminal of the energy storage device ES1, so that the distance between the energy storage device ES1 and the switch-diode arrangement S1 is no more than 10 mm.

[0033] Fig. 3 shows the switch-diode arrangement S1 according to Fig. 2 in a more detailed representation. The switch-diode arrangement S1 comprises a MOSFET 15 and a computing device 12 for computing the MOSFET 15. The data transmitted between the computing device 12 and the MOSFET 15 include, among other things, the voltage drop US1 across the switch-diode arrangement S1 and the current IS1 through the switch-diode arrangement S1. Furthermore, the switch-diode arrangement S1 comprises a temperature sensor T for determining the temperature TMP of the switch-diode arrangement S1.

[0034] The switch-diode arrangement S1 also includes a CAN bus interface 11, via which diagnostic data relating to the energy storage device ES1 is or can be transmitted. In the illustrated embodiment, the diagnostic data relating to the energy storage device ES1 includes its internal resistance RB, its capacitance CB, and its state of health SoH.

[0035] On the computing device 12, as shown in Fig.4, a diagnostic module 22 and, optionally, a temperature model 21 are implemented. Using the temperature model 21, the temperature or internal temperature TB of the energy storage device ES1 is determined depending on the output signal TMP (measured temperature value) of the temperature sensor T. If no temperature model is provided, the measured temperature value TMP determined using the temperature sensor T is used instead of the estimated temperature TB of the energy storage device ES1.By means of the diagnostic module, which in particular comprises a battery model of the energy storage device ES1, the internal resistance RB of the energy storage device ES1, the capacity CB of the energy storage device ES1 and the state of health SoH of the energy storage device ES1 are determined as a function of the temperature value TB, the voltage of the energy storage device ES1 (in particular measured via a measuring line not shown to ground and the connection at the positive pole by the switch-diode arrangement S1) and the current IS1 through the switch-diode arrangement S1.

Claims

[1] Motor vehicle (1) with a first energy storage device (ES1) for storing electrical energy, with a second energy storage device (ES2) for storing electrical energy, and with a starter-generator (SG) for starting an internal combustion engine (M) of the motor vehicle (1) or with a generator and a starter for starting an internal combustion engine (M) of the motor vehicle (1), wherein the first energy storage device (ES1) and the second energy storage device (ES2) are electrically connected to the starter-generator (SG) or the generator in such a way that the first energy storage device (ES1) and the second energy storage device (ES2) can be charged by means of the starter-generator (SG) or the generator, wherein the second energy storage device (ES2) is electrically connected to the starter-generator (SG) or the generator and / or starter by means of a switch-diode arrangement (S1), wherein a diode (D) is advantageously connected in parallel with the switch-diode arrangement (S1),wherein the switch-diode arrangement (S1) comprises a temperature sensor (T) arranged at the negative pole of the switch-diode arrangement (S1), and wherein the switch-diode arrangement (S1) is designed to output diagnostic data relating to the first energy store (ES1) and / or comprises a bus interface, in particular a CAN bus interface. [2] Motor vehicle (1) according to claim 1, characterized by that the switch-diode arrangement (S1) is mechanically connected directly to the positive pole of the first energy storage device (ES1). [3] Motor vehicle (1) according to claim 1 or 2, characterized by that the forward direction of the diode (D) is directed from the starter generator (SG) or generator and / or starter to the second energy storage device (ES2). [4] Motor vehicle (1) according to one of the preceding claims, characterized by that the switch-diode arrangement (S1) comprises a computing device with a temperature model. [5] Motor vehicle (1) according to one of the preceding claims, characterized by that the second energy storage device (ES2) and a lighting system of the motor vehicle, a steering system of the motor vehicle and / or a braking system of the motor vehicle are electrically connected in parallel. [6] Motor vehicle (1) according to one of the preceding claims, characterized by that the first energy store (ES1) is electrically connected to the lighting system of the motor vehicle, to the steering system of the motor vehicle and / or to the braking system of the motor vehicle by means of the switch-diode arrangement (S1). [7] Motor vehicle (1) according to one of the preceding claims, characterized by that the starter generator (SG) or the generator and / or starter is electrically connected to the lighting system of the motor vehicle, to the steering system of the motor vehicle and / or to the braking system of the motor vehicle by means of the first switch-diode arrangement (S1).

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