Drive system, vehicle with a drive system and a method for operating a drive system or a vehicle

Abstract

The invention relates to a drive arrangement (10) with features of claim 1, a vehicle (44) with such a drive arrangement (10) and a method for operating such a drive arrangement (10) or such a vehicle (44).

Description

Prior ArtThe invention relates to a drive arrangement having features of claim 1, to a vehicle having such a drive arrangement and to a method for operating such a drive arrangement or such a vehicle.In drive arrangements with an electric machine, heat is generated during operation. In order to avoid overheating of the drive arrangement and in particular of the electric machine, this heat can be dissipated. For this purpose, a cooling circuit can be provided in that a coolant is conveyed by means of a feed pump and conducted through the electric machine. Different cooling concepts can be used in this case.For example, the flow rate of the coolant can be kept constant. A disadvantage of this is that the feed pump can be operated at an unnecessarily high speed, since the flow rate is generally designed for the worst case and this does not always occur. This may result in excessive power consumption and generation of unnecessary (acoustic) noise.The flow rate of the coolant can, however, also be regulated as a function of the coolant temperature. A disadvantage here is that, due to the thermal mass of the coolant, the coolant temperature does not adapt rapidly enough to compensate for the rapid temperature fluctuations in the electric machine. As a result, the electric machine may be cooled insufficiently, so that overheating and damage may occur.Disclosure of the InventionAccording to the invention, a drive arrangement for a vehicle, in particular a motor vehicle, is proposed. The drive arrangement comprises a cooling circuit in which a coolant is or can be conveyed. The cooling circuit comprises an electric machine which is or can be supplied with the coolant. The cooling circuit comprises a coolant reservoir for storing the coolant. The coolant reservoir can be designed as a coolant sump. The cooling circuit comprises a coolant pump for conveying the coolant within the circuit. The cooling circuit comprises a first control device for controlling the coolant pump. The cooling circuit comprises a second control device for controlling the electric machine. The first control device is configured to control the coolant pump, in particular a delivery speed of the coolant pump, as a function of a prediction model. The coolant can thus be conveyed within the cooling circuit as a function of the prediction model.As a result, the energy consumption can be reduced and the cooling capacity can be optimized. Fast temperature fluctuations can be predicted and the coolant pump controlled in a targeted manner or the coolant flow (flow rate) controlled in a targeted manner.Predictive control of the coolant flow or the flow of the coolant within the cooling circuit can be implemented. The flow rate can be dynamically adapted to the anticipated cooling requirement. Thus, a higher flow rate can be implemented with a high cooling requirement and a lower flow rate can be implemented with a low cooling requirement. For this purpose, the rotational speed of the coolant pump can be increased or reduced accordingly, for example.According to a further development of the drive arrangement, the cooling circuit can have a heat exchanger. The heat exchanger can be configured to transport heat away (from the cooling circuit). The heat exchanger may be thermally coupled to an external cooling circuit. The external cooling circuit may be configured to transport the heat away to the outside. The external cooling circuit may include an inverter having a third controller. The third controller may be configured to control the inverter.As a result, the efficiency of the cooling circuit and thus of the drive arrangement can be further optimized.According to a development of the drive arrangement, the prediction model can be created on the basis of data from the first control device, the second control device and / or the third control device.It is likewise conceivable for the temperature of the coolant, the current requirement of the electric machine, the DC (direct current) bus voltage, the ambient temperature and / or the properties of the coolant, such as, for example. Flow and / or temperature can be incorporated into the creation of the prediction model.This makes it possible to make an accurate prediction of the development of the temperature in the cooling circuit. In particular, the flow rate of the coolant may be controlled not only based on the coolant temperature. Adjustments to the flow of coolant may be made even if the temperature of the coolant does not rise significantly (which may be the case during short phases with high demands). This makes it possible to prevent overheating of the electric machine and to implement the selection of an ideal rotational speed of the coolant pump.According to a development of the drive arrangement, the cooling circuit can comprise a first bypass line. The first bypass line may be configured to bypass the electric machine. The drive arrangement or the cooling circuit can comprise a transmission. The transmission may be supplied with coolant by means of the first bypass line. The coolant can thus be selectively conducted through the electric machine or past the electric machine and / or through the transmission (by means of the first bypass line).Alternatively or additionally, the cooling circuit can comprise a second bypass line. The second bypass line may be configured to bypass the heat exchanger. The coolant can thus be optionally conducted through the heat exchanger or past the heat exchanger (by means of the second bypass line).As a result, the coolant flow can be adapted flexibly according to the required requirement. The efficiency of the cooling circuit and thus of the drive arrangement can thus be further optimized.According to a further development of the drive arrangement, the cooling circuit can comprise at least one temperature sensor for detecting the temperature of the coolant. The temperature ascertained by means of the temperature sensor can be incorporated into the prediction model, in particular into its creation. The cooling circuit may include a filter for filtering the coolant. The cooling circuit can comprise at least one valve for controlling the first and / or the second bypass line.As a result, the efficiency of the cooling circuit and thus of the drive arrangement can be further optimized.According to the invention, a vehicle, in particular a motor vehicle, having a drive arrangement according to the above explanations is proposed.With regard to the advantages which can be achieved with the vehicle, reference is made to the relevant explanations relating to the drive arrangement. For a further configuration of the vehicle, the measures described in connection with the drive arrangement and / or the measures explained below can be used.According to a development of the vehicle, the vehicle can comprise a navigation device. The navigation device can be designed as a navigation system or a navigation device. The prediction model can be created on the basis of data from the navigation device.This makes it possible to make an accurate prediction of the development of the temperature in the cooling circuit.Thus, the electric machine of the drive arrangement of the vehicle may be precooled, for example before and / or during an uphill trip, to ensure that the long-lasting high loads (during the uphill trip) do not lead to overheating problems of the electric machine.Accordingly, the cooling of the electric machine of the drive arrangement of the vehicle, for example before and / or during a downhill trip, could be reduced, since a smaller generation of heat in the electric machine (during the downhill trip) is to be expected. The flow of coolant may be reduced in such phases, which may result in energy savings and an increase in the range of the vehicle.The cooling of the electric machine could be adjusted, for example, when the vehicle approaches its destination according to the data of the navigation device. Since it is assumed that the vehicle is no longer operating after reaching the destination, the electric machine can cool gradually without additional cooling by means of the cooling circuit being required.According to the invention, a method for operating a drive arrangement according to the above explanations or a vehicle according to the above explanations is proposed. The method comprises the step of:conveying the coolant within the cooling circuit as a function of the prediction model.With regard to the advantages which can be achieved with the method, reference is made to the relevant explanations relating to the drive arrangement or to the vehicle. For a further embodiment of the method, the measures described in connection with the drive arrangement or the vehicle and / or the measures explained below can be used.According to a development of the method, the method can comprise the step:controlling a delivery speed of the coolant pump as a function of the prediction model. By means of the delivery speed of the coolant pump, in particular the flow rate of the coolant within the cooling circuit can be controlled or regulated.As a result, the flow rate of the coolant can be controlled or regulated with simple means.According to a development of the method, the method can comprise the step:creating the prediction model on the basis of data of the first control device, the second control device, the third control device and / or the navigation device.As a result, the most accurate possible prognosis for the development of the temperature in the cooling circuit can be provided.Hereinafter, embodiments of the invention will be explained with reference to the accompanying drawings. The following are shown: FIG. 1 shows a schematic illustration of a drive arrangement, and FIG. 2 shows a schematic illustration of a vehicle.The drive arrangement bears the reference sign 10 overall in FIG. 1. the drive arrangement 10 is configured for a vehicle, in particular a motor vehicle. The drive arrangement 10 comprises a cooling circuit 12 in which a coolant 14 is or can be conveyed.The cooling circuit 12 comprises an electric machine 16. the electric machine 16 is supplied with the coolant 14 or can be supplied with the coolant 14.The cooling circuit 12 comprises a coolant reservoir 18 for storing the coolant 14, and the coolant reservoir 18 can be designed as a coolant sump.The cooling circuit 12 comprises a coolant pump 20.The cooling circuit 12 comprises a first control device 22 for controlling the coolant pump 20, and the cooling circuit 12 comprises a second control device 24 for controlling the electric machine 16.The first control device 22 is configured to control the coolant pump 20, in particular a delivery speed of the coolant pump, as a function of a prediction model.The drive arrangement may comprise a heat exchanger 26. The heat exchanger 26 may be thermally coupled to an external cooling circuit 28. The external cooling circuit 28 may include an inverter 30 with a third controller 32. The third controller 32 may be configured to control the inverter 30.The prediction model can be created on the basis of data of the first control device 22, the second control device 24 and / or the third control device 32.The cooling circuit 12 may have a first bypass line 34 for bypassing the electric machine 16. The cooling circuit may comprise a transmission 17. The transmission 17 can be supplied with the coolant 14 by means of the first bypass line 34. The coolant flow can be conducted through the electric machine 16 and / or past the electric machine 16 and in the present case through the transmission 17 by means of the first bypass line 34.The cooling circuit 12 may include a second bypass line 36 for bypassing the heat exchanger 26. The coolant 14 may be directed through the heat exchanger 26 or past the heat exchanger 26 via the second bypass line 36.The cooling circuit 12 may comprise at least one valve 42 for controlling the first and / or the second bypass line 34, 36. In the present case, the cooling circuit has two valves 42. A first valve 42 is configured to direct the coolant flow through the first bypass line 34 and a second valve 42 is configured to direct the coolant flow through the second bypass line 36.The cooling circuit 12 can comprise at least one temperature sensor 38 for detecting a temperature of the coolant 14. In the present case, the cooling circuit 12 has two temperature sensors 38. A first temperature sensor 38 is arranged downstream of the heat exchanger 26 and downstream of the second bypass line 36 in the flow direction of the coolant 14. A second temperature sensor 38 is arranged downstream of the electric machine 16, downstream of the transmission 17 and upstream of the coolant reservoir 18 in the direction of flow of the coolant 14.The cooling circuit 12 may include a filter 40 for filtering the coolant 14. The filter 40 is arranged in the present case upstream of the coolant pump 20 in the direction of flow of the coolant.FIG. 2 shows a schematic illustration of a vehicle 44, in particular of a motor vehicle, having a drive arrangement 10 according to the above explanations. The drive arrangement 10 can be the drive arrangement 10 shown in FIG. 1.The vehicle 44 may include a navigation device 46. The prediction model can be created on the basis of data from the navigation device 46.A method for operating a drive arrangement 10 according to the above explanations or a vehicle 44 according to the above explanations is described below. The drive arrangement 10 can be the drive arrangement 10 shown in FIG. 1. The vehicle 44 may be the vehicle 44 shown in FIG. 2. The method comprises the step of:conveying the coolant 14 within the cooling circuit 12 as a function of the prediction model.The method may comprise the step of:controlling a delivery speed of the coolant pump 20 depending on the prediction model. In this way, in particular the flow of the coolant 14 within the cooling circuit 12 can be controlled or regulated.The method may comprise the step of:creating the prediction model on the basis of data of the first control device 22, the second control device 24, the third control device 32 and / or the navigation device 46.

Claims

Drive arrangement (10) for a vehicle, in particular a motor vehicle, having a cooling circuit (12) in which a coolant (14) is conveyed, comprising: - an electric machine (16) which is or can be supplied with the coolant (14), - a coolant reservoir (18) for storing the coolant (14), - a coolant pump (20) for conveying the coolant (14) within the cooling circuit (12), - a first control device (22) for controlling the coolant pump (20), - a second control device (24) for controlling the electric machine (16), wherein the first control device (22) is configured to control the coolant pump (20), in particular a conveying speed of the coolant pump (20), as a function of a prediction model.The drive arrangement (10) according to claim 1, characterized in that the cooling circuit (12) comprises a heat exchanger (26), wherein the heat exchanger (26) is thermally coupled to an external cooling circuit (28), wherein the external cooling circuit (28) comprises an inverter (30) with a third control device (32) for controlling the inverter (30).Drive arrangement (10) according to Claim 1 or 2, characterized in that the prediction model is created on the basis of data from the first control device (22), from the second control device (24) and / or from the third control device (32).Drive arrangement (10) according to one of the preceding claims, characterized in that the cooling circuit (12) comprises a first bypass line (34) for bridging the electric machine (16) and / or a second bypass line (36) for bridging the heat exchanger (26).Drive arrangement (10) according to one of the preceding claims, characterized in that the cooling circuit (12) comprises at least one temperature sensor (38) for detecting the temperature of the coolant (14), a filter (40) for filtering the coolant (14) and at least one valve (42) for controlling the first and / or the second bypass line (34, 36).Vehicle (44), in particular motor vehicle, comprising a drive arrangement (10) according to one of the preceding claims.Vehicle (44) according to Claim 6, characterized in that the vehicle (44) comprises a navigation device (46), wherein the prediction model is created on the basis of data from the navigation device (46).Method for operating a drive arrangement (10) according to one of Claims 1 to 5 or a vehicle (44) according to Claim 6 or 7, comprising the step of: - conveying the coolant (14) within the cooling circuit (12) as a function of the prediction model.Method according to Claim 8, characterized bythe step of: - controlling a delivery speed of the coolant pump (20) as a function of the prediction model.Method according to Claim 8 or 9, characterized bythe step of: - establishing the prediction model on the basis of data from the first control device (22), from the second control device (24), from the third control device (32) and / or from the navigation device (46).

Images