Regulating device for regulating a cooling circuit for temperature control of a battery system having more than one heating and/or cooling element

Abstract

A regulating device for regulating a cooling circuit is described. The regulating device according to the disclosure includes a first regulating stage, wherein the first regulating stage is designed to determine, using one or more input variables, a cooling/heating power of the cooling circuit or a variable proportional thereto. The first regulating stage is also designed to determine a first control deviation. The first regulating stage is also designed to output a controlled variable of the first regulating stage comprising a desired temperature of a coolant or a variable proportional thereto, which is derived from the first control deviation. The regulating device according to the disclosure also includes a second regulating stage, wherein the second regulating stage is positioned in series with the first regulating stage and designed to receive the controlled variable of the first regulating stage as a control output. The second regulating stage is also designed to determine a second control deviation. The second regulating stage is also designed to output a controlled variable of the second regulating stage comprising an abstract signal, which is derived from the second control deviation.

Claims

1. A regulating device for regulating a cooling circuit for a battery including at least one of a plurality of heating elements and cooling elements, the regulating device comprising: a first regulating stage configured to: (i) determine, using one or more input variables, a cooling/heating power of the cooling circuit, or a variable proportional thereto; (ii) determine a first control deviation using the cooling/heating power or the variable proportional thereto; and (iii) output a controlled variable of the first regulating stage comprising a desired temperature of a coolant, or a variable proportional thereto, derived from the first control deviation; and a second regulating stage positioned in series with the first regulating stage and configured to: (i) receive the controlled variable of the first regulating stage as a control input; (ii) determine a second control deviation using the controlled variable of the first regulating stage; and (iii) output a controlled variable of the second regulating stage comprising an abstract signal derived from the second control deviation, the controlled variable of the second regulating stage provided to the at least one of a plurality of heating elements and cooling elements to regulate the cooling circuit.

2. The regulating device as claimed in claim 1, wherein the second regulating stage is further configured to convert the abstract signal into control commands for the at least one of a plurality of heating elements and cooling elements of the cooling circuit.

3. The regulating device as claimed in claim 1, wherein the first regulating stage is configured as a PI regulator.

4. The regulating device as claimed in claim 3, wherein a P component of the PI regulator of the first regulating stage comprises one or more characteristic fields configured to determine the cooling/heating power of the cooling circuit, or the variable proportional thereto, based on the one or more input variables.

5. The regulating device as claimed in claim 3, wherein an I component of the PI regulator of the first regulating stage is configured to provide the controlled variable comprising the desired temperature of the coolant, or the variable proportional thereto, based on the difference between the determined cooling/heating power of the cooling circuit, or the variable proportional thereto, and a measured cooling/heating power of the cooling circuit, or a variable proportional thereto.

6. The regulating device as claimed in claim 5, wherein the desired temperature of the coolant, or the variable proportional thereto, is determined as a controlled variable of the first regulating stage taking into account a constant, variable or measured mass flow of the coolant in the cooling circuit.

7. The regulating device as claimed in claim 5, wherein the I component of the PI regulator of the first regulating stage is configured to: (i) determine a magnitude of a difference between the determined cooling/heating power of the cooling circuit, or the variable proportional thereto, and a measured cooling/heating power of the cooling circuit, or a variable proportional thereto, (ii) compare the magnitude of the difference with a threshold value and (iii) output the magnitude of the difference as the controlled variable of the first regulating stage if the magnitude of the difference exceeds the threshold value.

8. The regulating device as claimed in claim 5, wherein the I component of the PI regulator of the first regulating stage is configured to limit the integration in the I component to ensure that a capability of the cooling circuit is not exceeded.

9. The regulating device as claimed in claim 1, wherein the second regulating stage is configured as an I regulator.

10. The regulating device as claimed in claim 1, wherein the controlled variable of the first regulating stage and the control input comprise a desired temperature of the coolant.

11. The regulating device as claimed in claim 1, wherein the one or more input variables comprise at least one of a current power with which a battery is being charged or discharged, a current thermal performance of the battery, a current maximum the cooling/heating power of the cooling circuit, a current ambient temperature, a current state of charge of the battery, a current battery temperature, a temperature difference between measured and desired battery temperatures, a maximum temperature of the battery or individual battery cells, and a variable proportional to one of the above-mentioned variables.

12. A cooling circuit for a temperature control of a battery system including at least one of a plurality of heating elements and cooling elements, the cooling circuit comprising: a first regulating stage configured to: (i) determine, using one or more input variables, a cooling/heating power of the cooling circuit, or a variable proportional thereto; (ii) determine a first control deviation using the cooling/heating power or the variable proportional thereto; and (iii) output a controlled variable of the first regulating stage comprising a desired temperature of a coolant, or a variable proportional thereto, derived from the first control deviation; and a second regulating stage positioned in series with the first regulating stage and configured to: (i) receive the controlled variable of the first regulating stage as a control input; (ii) determine a second control deviation using the controlled variable of the first regulating stage; and (iii) output a controlled variable of the second regulating stage comprising an abstract signal derived from the second control deviation, the controlled variable of the second regulating stage provided to the at least one of a plurality of heating elements and cooling elements to regulate the cooling circuit.

13. A motor vehicle, comprising: at least one regulating device for regulating a cooling circuit for a battery including at least one of a plurality of heating elements and cooling elements, each regulating device including: a first regulating stage configured to: (i) determine, using one or more input variables, a cooling/heating power of the cooling circuit, or a variable proportional thereto; (ii) determine a first control deviation using the cooling/heating power or the variable proportional thereto; and (iii) output a controlled variable of the first regulating stage comprising a desired temperature of a coolant, or a variable proportional thereto, derived from the first control deviation; and a second regulating stage positioned in series with the first regulating stage and configured to: (i) receive the controlled variable of the first regulating stage as a control input; (ii) determine a second control deviation using the controlled variable of the first regulating stage; and (iii) output a controlled variable of the second regulating stage comprising an abstract signal derived from the second control deviation, the controlled variable of the second regulating stage provided to the at least one of a plurality of heating elements and cooling elements to regulate the cooling circuit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Exemplary embodiments of the disclosure are described in detail using the FIGURE and the following description. In the FIGURES:

(2) The FIGURE shows schematically the regulating circuit of a regulating device according to the disclosure in combination with a cooling circuit and a battery system to be temperature controlled.

DETAILED DESCRIPTION

(3) In the FIGURE the regulating circuit of a regulating device 1 according to the disclosure is shown schematically in combination with a cooling circuit 3 and a battery system 4 to be temperature controlled.

(4) The regulating device 1 according to the disclosure is used to regulate the cooling circuit 3 with more than one heating and/or cooling element for the temperature control of a battery system 4. The regulating device 1 comprises for this a first regulating stage 1A and a second regulating stage 1B connected downstream of the first regulating stage 1A. The regulating stage 1A is configured as a PI regulator and the second regulating stage 1B as an I regulator.

(5) A current battery temperature t.sub.Bat of the battery system 4 is fed to the first regulating stage 1A of the regulating device 1 as an input variable. The PI regulator of the first regulating stage 1A comprises a characteristic field based P component, which determines a defined nominal cooling/heating power P.sub.nom of the cooling circuit 3 from the input variable t.sub.Bat. Instead of the nominal cooling/heating power P.sub.nom of the cooling circuit 3, a variable proportional thereto can also be determined from the characteristic field. The I component of the PI regulator of the first regulating stage 1A determines a control deviation from said nominal cooling/heating power P.sub.nom of the cooling circuit 3 and taking into account a measured current cooling/heating power P.sub.mess of the cooling system 3, e.g. by forming a difference of the two variables. Alternatively or additionally, the I component can also use the control difference of the battery temperature. Depending on the value of said control deviation, the PI regulator of the first regulating stage 1A outputs a controlled variable that is in the form of the defined nominal cooling power P.sub.nom or the temperature t.sub.nom of the coolant of the cooling circuit 3 or of a variable proportional thereto. During the determination of the controlled variable of the first regulating stage 1A, the defined nominal temperature t.sub.nom of the coolant of the cooling circuit 3 is calculated from P.sub.nom while taking into account a constant, variable or measured mass flow {dot over (m)} of the coolant in the cooling circuit 3.

(6) The controlled variable of the first regulating stage 1A is fed to the second regulating stage 1B as a control input or input value. The second regulating stage 1B is in the form of an I regulator. In the second regulating stage 1B, a control deviation is determined from a difference of the defined nominal temperature t.sub.nom of the coolant or the variable proportional thereto and a corresponding measurement variable, the current measured temperature t.sub.mess of the coolant or a corresponding variable proportional thereto. Depending on the control deviation of the second regulating stage 1B, an abstract signal S.sub.arb is then determined and output as a controlled variable of the second regulating stage 1B and thus as a regulating output of the regulating device 1 according to the disclosure.

(7) Said abstract signal S.sub.arb is then fed to a logic unit 2, which is used to convert the abstract signal S.sub.arb into specific control commands for the controllers of the plurality of heating/cooling elements of the cooling circuit 3. Specific characteristic curves for the specific cooling circuit 3 are stored in said logic unit 2, from which a defined control input for the controllers of the heating/cooling elements of the cooling circuit 3 results for each abstract signal S.sub.arb of the regulating device 1 according to the disclosure. The logic unit 2 can also comprise a plurality of different characteristic curves in this case, wherein the selection of the respective characteristic curve for the conversion of the abstract signal S.sub.arb can depend on other factors. Said other factors can be e.g. defined speed states of the automobile or defined ambient temperatures. This enables a defined abstract signal S.sub.arb to cause different operating states of the heating/cooling elements of the cooling circuit 3 depending on other factors.

(8) The logic unit 2 outputs control commands to the controllers of the plurality of heating/cooling elements of the cooling circuit 3 depending on the abstract signal S.sub.arb of the regulating device 1 and thus influences the temperature of the coolant in the cooling circuit 3, so that the current temperature t.sub.mess of the coolant approximates to the nominal temperature t.sub.nom of the coolant. The cooling circuit 3 can affect the temperature t.sub.Bat of the battery system 4 by means of the change of the current temperature t.sub.mess of the coolant.

(9) The current temperature t.sub.mess of the coolant of the cooling circuit 3 is reported back to the of regulating device 1. Thereby t.sub.mess is used in the second regulating stage 1B in order to determine the control deviation for the determination of the abstract signal S.sub.arb. Following a conversion of t.sub.mess into the current cooling/heating power P.sub.mess of the cooling circuit 3, optionally P.sub.mess is used to determine the control deviation in the first regulating stage 1A in order to determine t.sub.nom therefrom. In the regulating device 1 according to the disclosure, the conversion of t.sub.mess into P.sub.mess can be a component of the first regulating stage 1A of the regulating device according to the disclosure or even a separate logic unit.