HIGH-VOLTAGE VEHICLE HEATER AND METHOD FOR USING RECUPERATION POWER IN A VEHICLE

Abstract

The invention relates to a high-voltage vehicle heater (10), comprising a control device (12), comprising an electrical heating element (14) which is intended for heating a heating medium (16), and comprising a first data interface (18) by means of which a heating request signal can be received, said heating request signal representing an external heating request, wherein the control device (12) determines a first data set which represents at least one first electrical power with which the electrical heating element is to be operated in order to meet the external heating request, wherein the control device (12) determines, on the basis of a parameter data set, a second data set which represents at least one second electrical power which can be supplied to the electrical heating element (14) in addition to the first electrical power, without there being a risk of the vehicle heater (10) being damaged.

Claims

1. A high-voltage vehicle heater, having a control device, having an electrical heating element which is provided for heating a heating medium, and having a first data interface via which a heating request signal, representing an external heating request, can be received, wherein the control device determines a first data set which represents at least one first electrical power level with which the electrical heating element is to be operated in order to meet the external heating request, wherein the control device determines, on the basis of a parameter data set, a second data set which represents at least one second electrical power level which can be fed to the electrical heating element in addition to the first electrical power level, without the risk of damage to the vehicle heater.

2. The high-voltage vehicle heater as claimed in claim 1, wherein the second data set is output via the first data interface and/or a further data interface.

3. The high-voltage vehicle heater as claimed in claim 1, wherein the second data set contains information on how long the second electrical power level can be expected to be supplied to the electrical heating element.

4. The high-voltage vehicle heater as claimed in claim 1, wherein a recuperation signal, which indicates that the vehicle in which the vehicle heater is installed is in a recuperation mode, can be fed to said high-voltage vehicle heater via the first data interface and/or via a further data interface.

5. The high-voltage vehicle heater as claimed in claim 1, wherein the parameter data set comprises one or more of the following values: volume flow of the heating medium inlet temperature of the heating medium outlet temperature of the heating medium temperature of a shunt which is used to measure the electrical current flowing through the electrical heating element temperature of an electronic switch used for pulse width modulation of a supply voltage electrical resistance of the electrical heating element gradient of the inlet temperature of the heating medium gradient of the outlet temperature of the heating medium gradient of the temperature of a shunt which is used to measure the electrical current flowing through the electrical heating element gradient of the temperature of an electronic switch which is used for pulse width modulation of a supply voltage gradient of the electrical resistance of the electrical heating element number of start/stop cycles which the vehicle heater has run through heating power level which the vehicle heater has provided heating duration of the vehicle heater heating gradient supply voltage number of faults detected by the vehicle heater up to now type of faults detected by the vehicle heater up to now

6. A method for using recuperation power in a vehicle which has a recuperator, a battery and an electrical high-voltage vehicle heater, in which excess recuperation power is fed to the vehicle heater, which cannot be taken up, or is not to be taken up, by the battery, wherein it is determined how much additional recuperation power can at present be additionally taken up by the vehicle heater, without the risk of the vehicle heater being damaged.

7. The method as claimed in claim 6, wherein the recuperation power which is taken up by the vehicle heater is limited, either by the vehicle heater or already upstream of the vehicle heater, to the additional recuperation power which the vehicle heater can additionally take up without the risk of damage to the vehicle heater.

8. The method as claimed in claim 6, wherein the determined additional recuperation power which the vehicle heater can additionally take up at present without the risk of damage to the vehicle heater is taken into account during control of the recuperator.

9. The method as claimed in claim 5, wherein the determination of the additional recuperation power which can additionally be taken up by the vehicle heater at present without the risk of damage to the vehicle heater includes one or more of the following values: volume flow of the heating medium inlet temperature of the heating medium outlet temperature of the heating medium temperature of a shunt which is used to measure the electrical current flowing through the electrical heating element temperature of an electronic switch which is used for pulse width modulation of a supply voltage electrical resistance of the electrical heating element gradient of the inlet temperature of the heating medium gradient of the outlet temperature of the heating medium gradient of the temperature of a shunt which is used to measure the electrical current flowing through the electrical heating element gradient of the temperature of an electronic switch which is used for pulse width modulation of a supply voltage gradient of the electrical resistance of the electrical heating element number of start/stop cycles which the vehicle heater has run through heating power which the vehicle heater has provided heating duration of the vehicle heater heating gradient supply voltage number of faults detected by the vehicle heater up until now type of faults detected by the vehicle heater up until now

10. The method as claimed in claim 6, wherein a high-voltage vehicle heater is used as the vehicle heater.

Description

[0058] The high-voltage vehicle heater according to the invention and the method according to the invention are explained in more detail below with reference to the drawing, in which:

[0059] FIG. 1 shows a block circuit diagram of a vehicle which is equipped with the high-voltage vehicle heater according to the invention and in which the method according to the invention can be carried out.

[0060] As presented, a vehicle 8 has a high-voltage vehicle heater 10, a recuperator 30, a recuperation controller 28 and a battery 32. The vehicle heater 10 comprises a control device 12, which is assigned a shunt 24 for measuring the current flowing through an electrical heating element 14, and an electronic switch 26, for example in the form of an IGBTs, for pulse width modulation of a voltage which is applied to the supply voltage terminal 22. A heat exchanger 38 is connected in a manner not illustrated to a heating medium inlet 34 and a heating medium outlet 36. In the illustrated case, a mixture of water and anti-frost agent is used as the heating medium 16, as is well known in conjunction with vehicle heaters. The vehicle heater 10 has a first data interface 18 and a second data interface 20, via which it is possible to communicate with the control device 12. The data interfaces 18, 20 can be, for example, CAN or LIN bus terminals. FIG. 1 illustrates only the communication between the data interfaces 18, 20 and the recuperation controller 28. However, it is clear that communication also occurs additionally via the interfaces 18, 20 with other vehicle components, for example with the operator control parts of the vehicle heater or with other controllers of the vehicle.

[0061] During operation, the vehicle heater 10 receives, via the first data interface 20, a heating request signal which depends, for example, on a target temperature which has been input by a vehicle occupant. On the basis of this heating request signal, the control device 12 determines a first data set which represents at least a first electrical power level with which the electrical heating element 14 is to be operated in order to meet the external heating request.

[0062] In parallel or pseudo-parallel the control device 12 determines, on the basis of a parameter data set, a second data set which represents at least a second electrical power level which can be fed to the electrical heating element 14 in addition to the first electrical power level, without there being the risk of damage to the vehicle heater 10. The parameter data set which is used for this purpose can contain, for example, one or more or the following values: volume flow of the heating medium 16, inlet temperature of the heating medium 16, outlet temperature of the heating medium 16, temperature of a shunt 24 which is used to measure the electrical current flowing through the electrical heating element 14, the temperature of an electronic switch 26 which is used for pulse width modulation of a supply voltage, an electrical resistance of the electrical heating element 14, the gradient of the inlet temperature of the heating medium 16, the gradient of the outlet temperature of the heating medium 16, the gradient of the temperature of a shunt 24 which is used to measure the electrical current flowing through the electrical heating element 14, the gradient of the temperature of an electronic switch 26 which is used for pulse width modulation of a supply voltage, the gradient of the electrical resistance of the electrical heating element 14, the number of the start/stop cycles which the vehicle heater 10 has run through, the heating power which the vehicle heater 10 has provided, the heating duration of the vehicle heater 10, the heating gradient, the supply voltage, the number of faults which have been detected by the vehicle heater 10 up until now, the type of faults which have been detected by the vehicle heater 10 until now. In order to detect the value or values, the vehicle heater 10 comprises one or more suitable sensors, wherein such sensors are well known to a person skilled in the art and are therefore not illustrated in the FIGURE. For example, suitable evaluation circuits, which as such are also well known, can be provided, for example, for determining gradients. Values which are connected to the previous life of the vehicle heater 10 are received, for example, via a non-volatile storage element which is a component of the control device 12.

[0063] The second data set, which represents at least the second electrical power which can be fed to the electrical heating element 14 in addition to the first electrical power without the risk of damage to the vehicle heater 10 is communicated to the recuperation controller 28 via the first data interface 18 and/or the second data interface 20. Of course, the second data set can contain further information, for example about how long the second electrical power can be expected to be fed to the electrical heating element 14 and/or possible peak power levels and/or suitable average power levels. The recuperation controller 28 can then take into account this second data set during the determination of the optimum recuperation power, wherein, of course, further parameters are to be taken into account, for example instantaneous internal resistance of the battery 32. It is possible that the recuperation controller 28 feeds to the vehicle heater 10, via the first data interface 18 and/or via the second data interface 20, a recuperation signal which indicates that the vehicle 8 is in a recuperation mode. In this context, if appropriate further information can, of course, be transmitted, for example the level of the electrical power which is to be additionally fed to the electrical heating element 14, which is appropriate, in particular, when this additional power which is to be actually taken up by the electrical heating element 14 is lower than the second electrical power which has been determined by the control device 12.

[0064] With respect to the method according to the invention it is, as explained above, on the one hand conceivable that the vehicle heater 10 has the intelligence to determine how much additional recuperation power can additionally be taken up at present by the vehicle heater 10 without there being a risk of damage to the vehicle heater 10. However, it is also conceivable that the intelligence which is necessary for this purpose is provided at another location, for example at the recuperation controller 28 or another controller of the vehicle 8. It is also conceivable that the value or values of the parameter set which are used for the calculation are at least to a certain extent not detected by the vehicle heater 10 but rather externally, for example by means of sensors which are arranged in the water circuit of the vehicle 8 and/or at another suitable location. In a similar way, it is possible with respect to the method according to the invention that the recuperation power which is taken up by the vehicle heater 10 is limited, either by the vehicle heater 10 or already upstream of the vehicle heater 10, to the additional recuperation power which the vehicle heater 10 can additionally take up at a particular time without the risk of damage. If the vehicle heater 10 is responsible for the limitation of the power, the voltage which is applied to the electrical heating element 14 can be subjected to suitable pulse width modulation using the electronic switch 26. If the limitation of the power is already provided upstream of the vehicle heater 10, it must be ensured through suitable measures that the voltage which is applied to the voltage supply terminal 22 of the vehicle heater 10 does not assume excessively high values. Within the scope of the method it is also preferred that the recuperation controller 28 takes into account the determined additional recuperation power during the control of the recuperator 30. Therefore, precisely the quantity of kinetic and/or potential energy which can be appropriately used in the vehicle at a particular time can be converted into electrical energy by recuperation. Possibly present additional energy can then be converted into heat by the conventional vehicle brakes.

[0065] The features of the invention which are disclosed in the description above, in the drawings and in the claims can be essential to the implementation of the invention either individually or else in any desired combination.

LIST OF REFERENCE NUMBERS

[0066] 8 Vehicle [0067] 10 Vehicle heater [0068] 12 Control device [0069] 14 Heating element [0070] 16 Heating medium [0071] 18 Data interface [0072] 20 Data interface [0073] 22 Supply voltage terminal [0074] 24 Shunt [0075] 26 Switch [0076] 28 Recuperation controller [0077] 30 Recuperator [0078] 32 Battery [0079] 34 Heating medium inlet [0080] 36 Heating medium outlet [0081] 38 Heat exchanger