Method and Air-Conditioning System for Air-Conditioning an Electric or Hybrid Vehicle

Abstract

A method for air conditioning an electric or hybrid vehicle includes preconditioning a high voltage accumulator of the electric or hybrid vehicle. The electric or hybrid vehicle has an interior and the high voltage accumulator is air conditioned with an air-conditioning unit having a determined cooling potential. The high voltage accumulator has a current HVS temperature. The interior has a current interior temperature. During the preconditioning, the high voltage accumulator is supercooled in a preconditioning mode with the air-conditioning unit to an HVS temperature that is below an HVS operating temperature.

Claims

1. A method for air conditioning an electric or hybrid vehicle, the method comprising: preconditioning a high voltage accumulator of the electric or hybrid vehicle, wherein the electric or hybrid vehicle has an interior and the high voltage accumulator is air conditioned with an air-conditioning unit having a determined cooling potential, the high voltage accumulator has a current HVS temperature, the interior has a current interior temperature, and during the preconditioning, the high voltage accumulator is supercooled in a preconditioning mode with the air-conditioning unit to an HVS temperature that is below an HVS operating temperature.

2. The method as claimed in claim 1, wherein the preconditioning mode is activated depending on a cooling requirement profile for the interior, and depending on a cooling requirement profile for the high voltage accumulator.

3. The method as claimed in claim 2, wherein in the preconditioning mode the high voltage accumulator is supercooled as long as the cooling potential is at most partially used for cooling the interior.

4. The method as claimed in claim 3, wherein a future HVS temperature is predicted and the preconditioning mode is activated if said future HVS temperature exceeds a maximum HVS operating temperature.

5. The method as claimed in claim 4, wherein a future interior temperature is predicted and the preconditioning mode is activated only if said future interior temperature exceeds a maximum interior temperature.

6. The method as claimed in claim 4, wherein the future temperature is predicted as a future temperature profile for a period of time of at least 10 and at most 45 minutes.

7. The method as claimed in claim 6, wherein at least a future temperature is predicted by vehicle data being evaluated by means of a control unit.

8. The method as claimed in claim 7, wherein the vehicle data are selected from a quantity of vehicle data, comprising the current HVS temperature, the current interior temperature, and a current or future HVS requirement profile of the high voltage accumulator.

9. The method as claimed in claim 8, wherein the vehicle data comprise at least one environmental parameter of the vehicle.

10. The method as claimed in claim 8, wherein the vehicle data are data of a navigation system of the vehicle.

11. The method as claimed in claim 10, wherein, in the preconditioning mode, the high voltage accumulator is cooled by means of the air-conditioning unit as long as the current HVS temperature is greater than a minimum HVS operating temperature.

12. The method as claimed in claim 11, wherein the cooling potential is determined depending on a parameter which is selected from a quantity of parameters comprising: an environment parameter of the vehicle, an outside temperature, a maximum operating volume and an incident flow speed.

13. An air conditioning system for air conditioning an electric or hybrid vehicle which has an interior, the air conditioning system comprising: a high voltage accumulator; an air conditioning unit; and a control unit, wherein the air conditioning unit air conditions both the interior and also the high voltage accumulator, and the control unit when required switches the air-conditioning unit into a preconditioning mode in which, for the preconditioning of the high voltage accumulator, the high voltage accumulator is supercooled by means of the air conditioning unit to an HVS temperature below an HVS operating temperature.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG. 1 is a simplified block diagram of an air-conditioning system, and

[0028] FIG. 2 are the temperature profiles at the high-voltage accumulator and in the interior of an electric vehicle.

DETAILED DESCRIPTION OF THE DRAWINGS

[0029] FIG. 1 illustrates an air-conditioning system 2 schematically as a block diagram. The air-conditioning system 2 has an air-conditioning unit 4 which serves for air-conditioning both a high-voltage accumulator 6 and an interior 8 of an electric or hybrid vehicle (not shown specifically). The air-conditioning system 2 furthermore has a control unit 10 which is connected to diverse components via control and signal lines, which are illustrated as dashed lines. The control unit 10 thus controls the air-conditioning unit 4 and is furthermore connected to sensors 12 in the interior 8 and on the high-voltage accumulator 6 and to a navigation system 14 in order to determine vehicle data.

[0030] To explain a method for air-conditioning an electric or hybrid vehicle, in particular by means of the air-conditioning system 2, FIG. 2 shows a graph in which profiles of the temperature T at the high-voltage accumulator 6 and in the interior 8 of the vehicle are illustrated as HVS temperature H and interior temperature I in relation to the time Z. The time Z0 marks the present time, up to which the HVS temperature H and the interior temperature I have each been adjusted to a predetermined value, namely an HVS operating temperature H.sub.opt for the high-voltage accumulator 6, for example within a range of 25 to 29° C., and a feel-good temperature I.sub.opt for the interior 8, for example approximately 20° C. The HVS operating temperature H.sub.opt lies here within a HVS operating temperature interval with a minimum HVS operating temperature H.sub.min and a maximum HVS operating temperature H.sub.max, for example 20 and 40° C., respectively; the feel-good temperature I.sub.opt lies between a minimum feel-good temperature I.sub.min and a maximum feel-good temperature I.sub.max, for example 18 and 24° C., respectively. The temperatures H, I of a current HVS temperature H.sub.curr and of a current interior temperature I.sub.curr then lie correspondingly at the time Z0. A prediction of the HVS temperature HZ and of the interior temperature IZ is undertaken starting from the time Z0.

[0031] On the basis of vehicle data, for example data of the navigation system 14, the control unit 10 establishes a prediction of the temperature profiles as future temperature profiles HZ, IZ. In the exemplary embodiment shown here, there is a prediction to the effect that the temperatures H, I would each rise without additional measures. This is possibly the case with a high outside temperature. Without further air-conditioning, starting from the present time Z0, the HVS temperature H and the interior temperature I would then correspondingly rise. These are illustrated in FIG. 2 by the future HVS temperature HZ and the future interior temperature IZ. It becomes clear here that, in the future, there is a cooling need both for the high-voltage accumulator 6 and for the interior 8. In addition, it is predicted that the two future temperature profiles HZ, IZ, because of the rising profile, after a certain time, at a time ZK, will exceed the respective maximum HVS operating temperature H.sub.max and the maximum feel-good temperature I.sub.max. At the latest at this time ZK, there is then an in particular critical cooling requirement both for the high-voltage accumulator 6 and for the interior 8.

[0032] However, under some circumstances, the cooling potential of the air-conditioning unit 4 of the vehicle does not suffice to cover the entire cooling need of said two combined requirements. Therefore, in the future, a conflict will probably occur in respect of the distribution of the cooling potential to the interior 8 and the high-voltage accumulator 6. This is recognized by the control unit 10 which activates a preconditioning mode VK following the time Z0. While said preconditioning mode is active, the high-voltage accumulator 6 is supercooled below its HVS operating temperature H.sub.opt. This is illustrated in FIG. 2 as the actual HVS temperature HT. In the exemplary embodiment shown here, the entire cooling potential of the air-conditioning unit 4 is used first of all for supercooling the high-voltage accumulator 6, and therefore the actual interior temperature IT initially rises as predicted.

[0033] The preconditioning mode VK is activated in particular up to a time Z1 from which the cooling potential is used for cooling the interior 8 in order to avoid exceeding the maximum feel-good temperature I.sub.max. In particular, the originally predicted exceeding of the maximum feel-good temperature I.sub.max is prevented at the later time ZK here. In addition, the high-voltage accumulator 6 is at a sufficiently low temperature level so as not to exceed the maximum HVS operating temperature H.sub.max. despite cooling failing to materialize at the time ZK. The correspondingly required cooling power has already been input as a cold buffer into the high-voltage accumulator 6 in the preconditioning mode VK at a time at which no interior cooling was required.

[0034] Alternatively, the high-voltage accumulator 6 may be supercooled down to the minimum operating temperature H.sub.min, upon the achieving of which the preconditioning mode VK is, however, switched off. Excessive supercooling the high-voltage accumulator 6 is thereby avoided.

LIST OF DESIGNATIONS

[0035] 2 Air-conditioning system [0036] 4 Air-conditioning unit [0037] 6 High-voltage accumulator [0038] 8 Interior [0039] 10 Control unit [0040] 12 Sensor [0041] 14 Navigation system [0042] I Interior temperature [0043] I.sub.curr current interior temperature [0044] IT Actual interior temperature [0045] IZ Future interior temperature [0046] I.sub.max Maximum feel-good temperature [0047] I.sub.opt Feel-good temperature [0048] I.sub.min Minimum feel-good temperature [0049] H HVS temperature [0050] H.sub.curr Current HVS temperature [0051] HT Actual HVS temperature [0052] HZ Future HVS temperature [0053] H.sub.max Maximum operating temperature [0054] H.sub.opt Operating temperature [0055] H.sub.min Minimum operating temperature [0056] T Temperature [0057] VK Preconditioning mode [0058] Z0 Present time [0059] Z Time [0060] Z1 Time (end of the preconditioning mode) [0061] ZK Time (of a predicted conflict)

[0062] The foregoing disclosure has been set forth merely to illustrate the inventive method and system and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the inventive system and method may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof