DE102008054706A1 - Power supply network for a vehicle - Google Patents

Abstract

The invention relates to a power supply network for a vehicle having a drive source which can be driven by means of a starter drive source, in particular an electric motor, with a starter energy supply network (101) for supplying electrical energy to the starter drive source, a vehicle energy supply network (105) for supplying electrical energy to at least one vehicle consumer the vehicle energy supply network (105) is an electrical memory (119) for receiving excess electrical energy from the starter power supply network (101) is provided.

Description

State of the art

The The present invention relates to the field of electrical supply Energy in vehicles.

In Modern vehicle drives often become an electric motor as a starter used for starting an internal combustion engine. This is in particular a adequate dimensioning of electrical components necessary because When starting an internal combustion engine high power and high Currents are needed. So can the required peak currents for the starter ever according to size of the vehicle engine several 100 amperes up to 1000 amperes or even more. These high currents will be in conventional on-board network topologies from a wiring system or Starter battery powered and usually only by line resistance conditions and component internal resistance in the electrical system, such as an internal resistance of the starter battery or the starter, limited, what a high, impulsive starting torque of the starter can result. This leads to an increased mechanical stress, which extends the life of the starter reduced. In addition, carry the peak currents excessive voltage drops in the conventional on-board network as well as to an impairment of the electromagnetic Compatibility (EMC) at.

For targeted limitation of the peak currents, for example, an electrical resistor with a negative temperature coefficient in a main current path of an electromagnetically excitable rotor of the electric motor arranged or a current timing, as described in the document EP 1 369 569 are described, whereby the power loss can be reduced and a higher level of efficiency can be achieved. However, with clocking of high currents, voltage peaks or current peaks, which may also influence other vehicle components electromagnetically negatively, arise due to the ever-present supply inductances. The limitation of the electric current to be supplied to the electric motor, in particular in a start-up phase in which the electric motor mechanically drives, for example, an internal combustion engine, however, leads to the fact that not all the available or emitted electrical energy is used.

Disclosure of the invention

The Invention is based on the recognition that those of a starter power supply network, which is used to supply a starter with electrical energy will, unnecessary, surplus electrical energy, which in particular at a pulsed current limit is emerging into a vehicle power supply network that will supply from other vehicle consumers, such as an air conditioning system, is provided with electrical energy, can be fed. This will provide an overall more efficient utilization standing, reached electrical energy. You can do this the starter power supply network and the vehicle energy supply network, which are separate networks, being exchanged for exchange electrical energy in the vehicle power supply network electrical energy storage, such as a capacitor provided is the surplus coming from the starter supply energy network to store electrical energy.

Of the Energy storage of the vehicle power supply network, for example have a capacity ranging from millifarad to Farad is settled. Such capacities can be preferably realized with cap elements. It is possible, however, in the vehicle power supply network, a smaller capacity provided that the starter energy supply network also with an electrical energy storage, such as another Capacity is equipped. In a coupling of both Networks are the respective capacities therefore parallel to each other arranged, thereby increasing the total capacity becomes. For network coupling, for example, a diode provided which causes unidirectional energy exchange between the Capacity of the starter power supply network and the Capacity of the vehicle power supply network is made possible. By the electrical energy storage in the starter energy supply network, d. H. in the starter branch, and in the vehicle energy supply network, d. H. in the vehicle electrical system branch, which is coupled by means of a diode will be a rectification of the currents or the tensions which leads to a substantial avoidance of power surges and electromagnetic interference leads.

The arranged in the vehicle energy supply network energy storage also serves as a buffer memory, so that a transmission of voltage spikes in the on-board network and the associated disruption or destruction of electrical components can be avoided. Moreover, in the vehicle power supply network, which may include a vehicle electrical system, electrical components with lower breakdown voltages may be employed in the current path, thereby reducing the component cost. If the starter energy supply network is supplied with energy by means of a starter battery, it can therefore be arranged close to the power electronics be net, whereby a reduction of line inductances is achieved. By buffering the excess electrical energy, it is further possible to achieve an improvement in the EMC properties of the circuit arrangement for clocking the starter currents. Due to the substantial reduction of the voltage peaks in the timing of the starter current, electrical components with a lower breakdown voltage can also be used in the starter energy supply network. Furthermore, the starter battery can be arranged spatially away from the current timing inducing clock switch, whereby a flexible partitioning of power electronics and starter battery is possible so that they can be installed in a trunk and the power electronics, for example in a passenger compartment, without affecting other vehicle components electromagnetically negative ,

About that In addition, according to the invention in the magnetic Field of supply lines of the starter power supply network stored electrical energy at least partially into the vehicle energy supply network, d. H. in the electrical system, fed, causing the electrical system in the power cycle, in which the starter battery usually the electrical system not available, with additional electrical Energy is supplied. In addition, in the starter power network one Capacity provided, so can during the boot process usually the starter with electrical energy supplying starter battery through the starter side arranged Capacity to be supported. In this way The starter can provide more electrical power be put.

According to one Aspect, the invention relates to a power supply network for a vehicle with a means of a starter drive source, for example an electric motor, drivable drive source, for example an internal combustion engine. The power supply network includes a starter power supply network for supplying electrical power Power to the starter drive source and a vehicle power supply network for supplying electrical energy to at least one vehicle consumer. In the vehicle power supply network is preferably an electrical Energy storage arranged, which is provided by the starter power supply network to absorb excess electrical energy and into the vehicle power supply network connected to the starter power supply network is coupled to feed.

According to one Embodiment is in the starter power supply network an energy storage, such as a capacitor, for recording of excess electrical energy and to Supplying the same to the energy storage of the vehicle power supply network intended. This advantageously makes the use of overall smaller capacity allows.

According to one Embodiment is in the starter power supply network a starter battery in particular parallel to the further energy storage arranged, thereby advantageously in addition to a provision electrical power for the starter drive source too efficient storage of excess electrical Energy is enabled.

According to one Embodiment is the starter power supply network with the vehicle power supply network via a unidirectional electric Connecting element, in particular connected via a diode. As a result, a reaction of the Vehicle power supply network to the starter power supply network prevented.

According to one Embodiment is parallel to the energy storage of Vehicle energy supply network another energy storage, in particular, a backup battery provided, which, if necessary advantageously additional energy for supplying from other electric vehicle consumers.

According to one Embodiment, this further energy storage means a switch switchable or disconnectable, so this in advantageously switched on only when needed.

According to one Embodiment is in the starter power supply network a tactile circuit element, in particular a tactile switch, for limiting an amplitude of one of the starter drive source to be supplied provided electric current. This can be done in an advantageous manner a clocked current limit can be realized.

According to one Embodiment is parallel to the tactile switching element another switching element, in particular a further switch, arranged, which advantageously a larger electrical Conducting electricity as the tactile switching element and switched on when needed can be.

According to one Embodiment is the starter power supply network on the output side by means of a reversely polarized diode with connected to a ground terminal, which advantageously provides overvoltage protection is realized.

According to one embodiment, the driving is zeugenergieversorgungsnetzwerk output side connected to a generator for generating electrical energy. The generator can be provided, for example, a generator of a vehicle electrical system and for supplying electrical energy consumers such as an air conditioning system. An energy return from the vehicle power supply network to the starter power supply network at a startup operation can be prevented by means of a diode operable in reverse operation between the starter power supply network and the vehicle power supply network. The generator may also be part of the vehicle power supply network.

According to one Aspect, the invention relates to a power supply method for a vehicle with a means of a starter drive source, for example an electric motor, drivable drive source. The energy supply method includes supplying electrical energy to the starter drive source by means of a starter power supply network, the feeding electrical energy to at least one vehicle consumer means of a vehicle power supply network, transferring excess electrical energy from the starter power supply network the vehicle power supply network, saving the excess electrical energy, in particular in the vehicle energy supply network and feeding in the stored surplus electrical energy in the vehicle energy supply network.

Further Embodiments will be made with reference to the accompanying drawings Figures explained in more detail. Show it:

1 a schematic diagram of a power supply network;

2 a schematic diagram of a power supply network; and

3 a schematic diagram of a power supply network.

This in 1 illustrated power supply network includes a starter power supply network 101 , which by means of a diode 103 with a vehicle power supply network 105 is coupled. The starter power supply network 101 includes a starter battery 107 , which are parallel to an electrical energy storage 109 between an input of a switch 111 , which by means of a clock signal 113 can be clocked, and a ground connection 115 is arranged. An output of the switch 111 is connected to a power connection of a starter drive source, in particular an electric motor. The output of the switch 111 is also connected via a reverse direction, optional diode to the ground terminal 115 connected.

The diode 103 Downstream vehicle energy supply network 105 includes an electrical energy storage 119 , which has an output of the diode 103 with the ground connection 115 combines. Parallel to the memory element 119 is another electrical energy storage, in particular an auxiliary battery 121 arranged. The more capacity 119 is also parallel to a generator 123 arranged, which, for example, an electrical consumer 125 supplied with electrical energy.

In operation, the starter drive source 117 from the starter battery 107 supplied with electrical energy. The electric current is preferred by means of the switch 111 clocked, wherein the freewheeling element in the shape of the diode 115 is provided as a surge protection. The electrical energy storage 109 is used as a Kommutierungsspeicher and may for example be designed as a double-layer capacitor.

In clock mode, the at the open switch 111 current impressed by the example present Zuleitungsinduktivitäten through the electrical energy storage 109 recorded and stored as excess electrical energy. Due to the diode arranged in the direction of flow 103 This excess electrical energy can be fed into the vehicle energy supply network and in the electrical energy storage 119 get saved. This excess energy can be the electrical consumer 125 , which works together with the generator 123 a wiring system 127 can be supplied. The parallel to the electrical energy storage 119 arranged, further electrical energy storage 121 can, for example, to support the vehicle energy supply network 105 especially when operating the starter drive source 117 be used. Optionally, the electrical energy storage 121 by means of a switch 215 be switched on or off.

2 shows a circuit diagram of a power supply network, which on the in 1 illustrated power supply network based. In contrast to this is parallel to the diode 103 a switching element 201 , For example, a switch arranged. The diode 103 and the switching element 201 can be realized together in the form of a semiconductor switch. Further, in the in 2 shown circuit diagram for a better understanding of the operation of the device replacement circuit elements such as a Leitungsin duktivität 203 , an inductance 205 the starter drive source 117 , a line inductance 207 . a serial internal resistance 209 of the electrical energy storage 107 , a line inductance 211 as well as a series internal resistance 213 of the electrical energy storage 121 shown.

3 shows a schematic diagram of a power supply network, which on the in 2 illustrated circuit diagram based. In contrast, this is parallel to the switch 111 another switch 301 arranged, which at an increased power requirement of the starter drive source 117 can be closed. Thus, the switch 111 for example, be designed as a semiconductor switch, while the other switch 301 for example, is designed as a relay.

With the in the 1 to 3 illustrated embodiments, in particular the goal is achieved, a regulation or limitation of the switch current to a maximum value, for example, depending on the starting unit to be launched provides the required starting power, and / or the current system conditions such. B. an external and / or a drive source temperature can be selected so that always the optimum in terms of comfort and life start current can be provided. However, if the current limit can not supply enough starting current, which may be the case for example during a cold start, or if the switch 111 can not absorb enough power, so the switch can 301 be closed, so that enough power can be passed.

For starting a drive source by means of the starter drive source 117 for example, the switch 201 opened and the optional switch 215 to support the on-board network by the further energy storage 121 closed. To start the drive source, such as an internal combustion engine, via the starter drive source 117 will be the switch first 111 closed. The current through the starter drive source 117 despite the attenuation of the system inductances 203 . 207 respectively. 211 increase until a current limit is reached, which was provided as a maximum current value, for example 600A. At the same time, the electrical energy storage 109 at least partially charged.

One in the 1 to 3 not shown control opens, for example, depending on the respective time constants in the respective circuits the switch 111 by means of the clock signal 113 , which eliminates electrical power from the energy store 107 into the energy or commutation memory 109 flows and charges it, so that at the energy storage 109 the voltage increases. This prevents an abrupt demolition of a high electric current caused by the line inductance 207 from the energy store 107 flows. The line inductance 207 However, the electric current continues, so that with a suitable choice of the capacity of the electrical energy storage 109 the voltage present at the energy storage 109 is greater than the vehicle electrical system voltage.

The in the energy storage 109 stored, excess energy can through the diode 103 , which is used as a coupling element, in the vehicle power supply network 105 and especially in the on-board network 127 flow. The diode 103 can, as stated above, as a substrate diode of a semiconductor switch, which switches the switch 201 realized, implemented. The energy storage 119 absorbs the excess energy, which also smooths the on-board network 127 to be supplied. This is advantageous insofar as a smoothing effect of the energy storage 121 , which is used as a column energy storage, because of the line inductance 211 as well as the internal resistance 213 is restricted.

Indicates the energy storage 119 sufficient storage capacity, which may be arranged for example in the milli-farad to farad range, so can on the other energy storage 109 in the starter power supply network 101 be waived. Preferred is then a corresponding current-sized diode 103 use. In operation, the current through the starter drive source 117 driven by the inductors 203 and 209 continue to flow, so that an abrupt power cut in the starter energy supply network, ie in the starter circuit, can be avoided.

All in all thus abrupt changes in current can be avoided so that it can also be avoided that high surges be induced. Because with a sudden demolition of an electric Currents with, for example, 600 A can cause overvoltages up to several 100 V arise.

The electric current sinks through the starter 117 below a certain lower limit value, which for example has a hysteresis arranged around a designated current setpoint, the switch can 111 closed again, causing the current to rise again and the voltage across the switch 111 due to the internal resistance 209 decreases. In this way, the energy storage 109 continue to discharge and the vehicle energy supply network 105 be supplied to the power from the energy storage 121 to support.

If the starting current drops after starting up or after starting the starter drive source 117 or by the starter drive source 117 driven internal combustion engine, so now a reduced starter power is required. Therefore, the switch 111 be closed, whereby the starter current timing is set. After starting by the starter drive source 117 driven drive unit, such as an internal combustion engine, the switch 111 be opened again. Thus, in normal operation of the energy storage 109 over the switch 201 the on-board network 127 provide additional energy.

In a cold start, as mentioned above, the current carrying capacity of the switch 111 exceeded, which may be the case in particular when the switch 111 was designed as a semiconductor switch. In this case, there is the possibility of the starting current through the switch 301 , which may be designed as a relay to conduct. When opening the switch 301 can also advantageously the freewheeling element 114 , which may be implemented as a diode, and the energy storage 109 , which is designed as a commutation memory, can additionally be used to reduce switching voltage spikes. In addition, the in the line inductance 207 stored magnetic energy in the on-board network 127 be fed.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• EP 1369569 [0003]

Claims (11)

Power supply network for a vehicle having a drive source which can be driven by means of a starter drive source, in particular an electric motor, comprising: a starter power supply network ( 101 ) for supplying electric power to the starter drive source; a vehicle energy supply network ( 105 ) for supplying electrical energy to at least one vehicle consumer, wherein in the vehicle energy supply network ( 105 ) an electrical memory ( 119 ) for absorbing excess electrical energy from the starter power supply network ( 101 ) is provided. Power supply network according to claim 1, wherein in the starter power supply network ( 101 ) an electrical memory ( 109 ), in particular a capacitor, for storing the excess electrical energy is provided, the excess electrical energy to the memory ( 119 ) of the vehicle energy supply network ( 105 ). Power supply network according to claim 2, wherein in the starter power supply network ( 101 ) a starter battery ( 107 ) parallel to the further electrical memory ( 109 ) is arranged. Power supply network according to one of the preceding claims, wherein the electrical memory ( 109 ) of the starter power supply network ( 101 ) with the electrical storage ( 109 ) of the vehicle energy supply network ( 105 ) via a unidirectional electrical connection element ( 103 ), in particular via a diode. Power supply network according to one of the preceding claims, wherein the vehicle energy supply network ( 105 ) another electric memory ( 121 ), in particular a support battery, which is parallel to the electrical storage ( 119 ) is arranged. Power supply network according to claim 5, wherein the further electrical memory ( 121 ) by means of a switch ( 215 ) is switched on or off. Power supply network according to one of the preceding claims, wherein in the starter energy supply network ( 101 ) a tactile switch ( 111 ) is provided for limiting an amplitude of an electric current to be supplied to the starter drive source. Power supply network according to claim 7, wherein parallel to the tactile switch ( 111 ) a welterer switch ( 301 ) is arranged. Power supply network according to one of the preceding claims, wherein the starter energy supply network ( 101 ) on the output side by means of a reversely polarized diode ( 114 ) with a ground connection ( 115 ) connected is. Power supply network according to one of the preceding claims, wherein the vehicle energy supply network ( 105 ) on the output side with a generator ( 125 ) connected is. Energy supply method for a vehicle with a means of a starter drive source, in particular a Electric motor, drivable drive source, in particular an internal combustion engine, With: Supplying electrical energy to the starter drive source by means of a starter power supply network; Respectively electrical energy to at least one vehicle consumer means a vehicle power supply network; Transfer excess electrical energy from the starter power supply network the vehicle power supply network; Save the excess electrical energy; and Feeding the saved surplus electrical energy into the vehicle energy supply network.