ELECTRICAL VEHICLE

Technical field of the invention

The invention relates to a method for thermal regulation of electric car parts, and an assembly wherein at least one heat storage unit, at least one battery, at least one external heat exchanger, at least one cabin and a cabin heating/cooling system are interconnected in a control circuit.

Background art

The prior art includes several solutions for providing temperature control for batteries in electric cars.

A prior art solution is disclosed in the document EP 2,956,985 Bl. The document discloses a vehicle comprising at least one electric drive, at least one energy accumulator (battery) adapted to supply power to the electric drive, and at least one current collector adapted for charging the energy accumulator. The at least one energy accumulator (battery) is connected to the current collector via at least one charge converter for charging the at least one energy accumulator. A characteristic feature of this technical solution is that the vehicle comprises a central cooling system and at least one closed cooling circuit with liquid coolant in order to cool the at least one energy accumulator (battery), wherein the at least one cooling circuit comprises at least one heat exchanger for the at least one energy accumulator and a heat exchanger for the at least one charge converter. Another characteristic feature of the technical solution is that the heat exchanger of the at least one charge converter is arranged before the heat exchanger of the at least one energy accumulator (battery).

A fundamental problem with prior art battery cooling systems installed in electric vehicles is that the thermal energy generated during battery cooling is wasted, and therefore such systems waste high amounts of energy.

Objective of the invention

The objective of the invention is to provide a method and assembly for providing temperature control for components of electric cars that provides highly safe temperature control for the battery and the cabin of an electric car by including a heat storage unit and making use of the system of the outside environment and the cabin, in a more economical manner compared to existing technical solutions.

The objective of the invention is realised by providing a method for controlling the temperature of the components of electric cars wherein at least one heat storage unit, at least one battery, at least one external heat exchanger, at least one cabin and a cabin heating/cooling system are interconnected in a control circuit, wherein, for operating the control circuit, temperature values TA, TT, T _ut , Tk, T3, T9 and T ₁₀ are measured, where TA IS the measured value of battery temperature, TT is the measured value of the temperature of the heat storage unit, T _ut is the measured value of cabin temperature, T is the measured value of ambient (outside) temperature, T ₃ is the temperature measured in the control circuit at the output of the heat storage unit, T ₉ is the temperature measured in the control circuit downstream of the cabin, and T ₁₀ is the temperature value measured upstream of the external heat exchanger, assigning to the TA value multiple constant temperature threshold values that constitute temperature ranges, assigning to the TT value multiple constant temperature threshold values that constitute temperature ranges, and assigning to the T _ut value multiple constant temperature threshold values that constitute temperature ranges and are kept constant with respect to the value set as the desired cabin temperature, and comparing, in multiple steps, the temperature values measured in the course of the method with the corresponding temperature threshold values, and, depending on the relationship between the compared threshold values, including in or excluding from the control circuit the heat storage unit, the at least one battery, the at least one external heat exchanger, the at least one cabin, and the cabin heating/cooling system.

In a preferred embodiment of the method according to the invention the priority order of the components is as follows: battery, heat storage unit, cabin heating/cooling system.

In another preferred embodiment of the method according to the invention the steps of the method are automatically repeated upon detecting a change of an input parameter.

In a further preferred embodiment of the method according to the invention the steps of the method are automatically repeated at given intervals.

In another preferred embodiment of the method according to the invention the heat generated during the operation of the battery is at least partially carried off. In a further preferred embodiment of the method according to the invention the heat generated by and carried off from the battery is at least partially stored in a heat storage unit.

In a still further preferred embodiment of the method according to the invention the heat generated by and carried off from the battery and stored in the heat storage unit is at least partially utilized for heating the cabin.

In another preferred embodiment of the method according to the invention battery tempering is carried out in a time-staggered manner, thereby preventing the battery from being utilized in a cold state.

The objective of the invention is further realized by providing an assembly for providing temperature control for components of an electric vehicle, comprising and fluid dynamically interconnecting at least one heat storage unit, at least one battery, at least one heat exchanger, and at least one cabin heating/cooling system known per se, wherein the components of the assembly can be independently included in or excluded from a circuit provided by the assembly, characterised in that it comprises a control unit operated applying the method according to any of the preceding claims.

Brief description of the drawings

The method and assembly according to the invention are explained in detail below referring to the attached figures, where

Fig. 1 is a schematic depiction of a preferred embodiment of the assembly according to the invention,

Fig. 2 is a flowchart illustrating a part of the algorithm of the first level of the method according to the invention,

Figs. 3-5 are flowcharts illustrating algorithm parts A, B, C of the second level of the method according to the invention, and

Figs. 6-24 are flowcharts illustrating algorithm segments 1-19 of the third level of the method according to the invention.

Modes for carrying out the invention

Fig. 1 illustrates an exemplary control circuit. The exemplary control circuit includes the following components: - 101 - heat storage unit

102 - battery

104 - cabin

105 - cabin heating/cooling system

103 - cabin heat exchanger adapted for interconnecting the system with the cabin 104 and the cabin heating/cooling system 105

106 - heat exchanger

- PI - circulator pump equipped with a motor

- VI, V3, V4, V9 - motorized directional control valves

The circuit requires the following pipes and pipe fittings: The components of the control circuit are arranged such that they can be independently adjusted according to current parameter settings. In a preferred implementation according to the invention, this can be achieved by arranging branches including the components and parallel “empty” branches in the control circuit utilizing directional control valves VI, V3, V4, V9.

However, other similarly configured control circuit arrangements are also suitable for carrying out the method according to the invention, where the control circuit comprises at least one heat storage unit 101, at least one battery 102, at least one heat exchanger 106, and at least one system adapted for cabin heating and cooling, which components can be individually included in or excluded from the control circuit.

The circuit also comprises a heat storage unit that is essentially implemented as a heat storage unit filled with a phase change material (PCM). The capacity of the heat storage unit and the applied phase change material (PCM) are selected for the highest heating demand such that the battery does not cool below a given temperature, preferably for example below 21 °C in case the battery is cooled down by low ambient temperatures, while also ensuring by cooling that the battery temperature does not rise above 44 °C. In a preferred configuration the phase- change range of the phase change material (PCM) is between 30 and 35°C.

For properly interpreting further figures (Figs. 2-24) a description of various measured and adjusted parameters is required.

The heat storage unit 101 requires the following temperature threshold values in the course of the control process: - T _Tmax2 is the maximum allowed temperature of the heat storage unit; above this temperature the unit cannot provide the required cooling performance, in which case the cabin cooling is switched on; in a preferred embodiment this temperature value is 33°C

- T _Tmaxl is a temperature value above which it is not mandatory to apply cooling, but if “free cooling” can be made use of then it is worth utilizing; in a preferred embodiment this temperature value is 32°C

- T _Tmax0 is a temperature value above which it is not mandatory to apply cooling; however, if possible the cooling capacity of the cabin is to be utilized. In a preferred embodiment this temperature value is 31°C

- T _Tmin0 is the minimum allowed temperature of the heat storage unit; should it sink below this temperature, the unit would not be able to cope with the maximum heating demand; in a preferred embodiment this temperature value is 25 °C

In the case of the battery 102 the most important task of the system is to keep the battery temperature between appropriate limits. Keeping the battery temperature between the appropriate limits thus overrides all of the other tasks. The ideal operating temperature range of the battery is 20-40°C; moreover, temperatures under 5°C - or with certain types, 0°C - or temperatures over 45 °C may cause damage to the battery.

The battery 102 requires the following temperature threshold values in the course of the control process:

- T _Amax3 : if the battery temperature rises above 45 °C then it can fail during the operation (charging or driving) of the car, so the battery has to be switched off. For the purposes of the control algorithm a lower threshold value is applied so that the battery need not be switched off completely (i.e. only the operation of the car is halted but the battery can still be utilized for emergency cooling); in a preferred embodiment this temperature value is 44°C

- T _Amax2 : above this temperature the battery is still in the ideal operating range, but is close to the emergency stop temperature which cannot be allowed i.e. in this operating range cooling is very important, to provide cooling the heat storage unit is turned on; in a preferred embodiment this temperature value is 39°C

- T _Amaxl : above this temperature the battery is still in the ideal operating range and is not close to the emergency stop temperature, so it is sufficient to apply cooling utilizing the heat exchanger; in a preferred embodiment this temperature value is 38 °C - T _AmaxQ : exceeding this temperature indicates that the battery has started to heat up, so cooling has to be commenced with the help of the cabin; in a preferred embodiment this value is 37 °C

- T _Amin0 : below this temperature we are near the edge of the ideal operating range so heating has to be started utilizing the heat storage unit; in a preferred embodiment this temperature value is 22 °C

- T _Aminl : below this temperature the battery is near the edge of the ideal operating range which cannot be allowed i.e. heating is very important (cabin heating is turned on); in a preferred embodiment this temperature value is 21 °C

- T _Amin2 : battery temperature cannot drop below 5 °C because otherwise it can fail during the operation of the car i.e. it has to be switched off. For the purposes of the control algorithm a higher threshold value is applied so that the battery need not be switched off completely (i.e. only the operation of the car is halted but the battery can still be utilized for emergency cooling); in a preferred embodiment this temperature value is 6 °C.

The desired temperature of the cabin 104 is adjusted by the passengers utilizing a thermostat, giving a value T _thermostat in relation to which the below limit values are specified: Tutmaxi ⁼ T thermostat + 2: above this temperature the cabin has to be cooled utilizing the cabin cooling; in a preferred embodiment this temperature value is 24 °C

- T _utmax0 = T _thermostat 4- 1: above this temperature cabin cooling has to be started; in a preferred embodiment this temperature value is 23 °C T'utmino ⁼ Tthermostat ~ 1 ^; below this temperature cabin heating has to be started; in a preferred embodiment this temperature value is 21 °C Tutmini = Tthermostat ~ 2: below this temperature the cabin has to be heated utilizing the cabin heating; in a preferred embodiment this temperature value is 20 °C

The heat storage unit is not adapted for keeping the cabin 104 at a desired temperature, this function is performed by the cabin heating/cooling system; however, in certain cases the control circuit allows for utilizing the excess heat or excess heating capacity of the heat storage unit.

The cabin heating/cooling system is essentially adapted for heating and/or cooling the cabin 104 i.e. for controlling the temperature thereof. However, the control circuit allows its application for emergency heating or cooling purposes, i.e. it can also be applied for heating/cooling the battery 102 and the heat storage unit 101.

An external heat exchanger (the heat exchanger 106 open to the outside air) is also included. In certain cases, this can be applied for “free cooling” utilizing outside air.

The system also includes a cabin heat exchanger, i.e., a heat exchanger adapted for connecting the cabin heating/cooling system to the battery temperature control system, and also comprises a fan connected to the cabin; it is incapable of heating or cooling on its own and has no “demands” so its status is not monitored.

The method involves controlling some of the above-described components of the control circuit. Because the operation of the individual components of the control circuit depends on various environmental parameters and also on the components themselves, a priority hierarchy needs to be established among the components.

Since the system is primarily adapted for controlling the temperature of the battery 102, in the course of the method first the “certain” parameters are selected according to considerations related to the battery 102, then, based on the operational needs of the heat storage unit 101 the values of the missing parameters are established, and then, in the third round of checks the remaining parameters are set according to cabin-related considerations. If a value is not obtained for a parameter value for some parameter by the method during the three-level check process, then the existing parameter value is retained.

The control algorithm includes adjusting the following parameters:

- Battery:

In case of a YES signal: the car can be operated (charging and/or driving)

In case of a NO signal: the car cannot be operated

Battery disconnected: the battery is not part of (is excluded from) the system

- Heat storage unit:

In case of a YES signal: it forms a part of (is included in) the system In case of a NO signal: it is not part of (is excluded from) the system

- Heat exchanger:

In case of a YES signal: it forms a part of (is included in) the system In case of a NO signal: it is not part of (is excluded from) the system - Cabin:

In case of a YES signal: it forms a part of (is included in) the system In case of a NO signal: it is not part of (is excluded from) the system

- Cabin heating/cooling:

In case of a COOLING signal: it operates in cooling mode In case of a HEATING signal: it operates in heating mode In case of a NO signal: it is not part of (is excluded from) the system

2 systems disconnected: cabin HEATING/COOLING is in operation but the cabin and the cabin HEATING/COOLING system are not connected to the system that contains the battery.

The highest priority of the method according to the invention is protecting the battery while providing maximum performance, so in the course of the control method first the conditions/demands set by the battery are examined. This is followed by examining the parameters related to the heat storage unit because keeping the heat storage unit at the appropriate temperature is very important for meeting the demands of the battery. Then, last in the order of priority, the cabin parameters are checked because the state of the cabin is not critical from the aspect of the electric car’s operation; however it is more economical to keep it in the appropriate temperature range without utilizing the cabin heating/cooling system.

In the following, the method according to the invention is described referring to a flow chart laid out on three levels. Fig. 2 illustrates the first level of the method according to the invention. Based on the measured temperature data TA a decision is made whether it is necessary to cool or heat the battery or the battery temperature is within the limits described above.

Part A of the algorithm is illustrated in Fig. 3. Part A of the algorithm is executed in case the battery temperature is higher than T _Bmax0 . In such a case a check is performed for the cooling cases of the battery that result in eleven distinct algorithm segments which are indicated by reference numerals 1-11 in the drawings and are shown in Figs. 6-16, respectively.

Part B of the algorithm is illustrated in Fig. 4. Part B of the algorithm is executed in case the battery need not be heated or cooled; in such cases the battery can be in operation but is disconnected from the system. In this case six further distinct algorithm segments are drawn up that are indicated by reference numerals 12-17 in the drawings and are shown in Figs. 17-22, respectively. Part C of the algorithm is illustrated in Fig. 5. Part C of the algorithm is executed in case the battery has to be heated because the battery temperature is lower than T _BmaxQ . In this case two further distinct algorithm segments are drawn up that are indicated by reference numerals 18-19 in the drawings and are shown in Figs. 23-24, respectively.

In the subsequent part of the method one of the algorithm segments 1-19 is executed, depending on which one of the algorithm segments 1-19 needs to be applied based on the data measured according to algorithm parts A, B, or C above.

If the battery requires cooling and the temperature of the heat storage unit is lower than T _T rnin _O ’ the heat storage unit needs to be heated, so algorithm segment 1 (shown in Fig. 6) is executed. Because the battery needs to be cooled and the heat storage unit has to be heated, both components are included in the control circuit, so the heat storage unit is utilized for cooling the battery. The heat exchanger is not operated because if the heat storage unit has to be heated then outside temperature is surely lower than the temperature of the heat storage unit, so outside air cannot be utilized for heating the heat storage unit. (If the heat storage unit has to be heated then we can be sure that the battery does not require intensive cooling, i.e. its temperature is lower than T _Bmax3 .) This is followed by checking the cabin state. If the cabin needs heating, then the cabin is connected to the circuit. If the heating demand of the cabin is higher ( T _ut <T _utminl ), the cabin heating system turns on and forms a separate system together with the cabin. If the heating demand of the cabin is not too high, then it is checked whether, if the cabin is heated applying the battery (i.e. it is included in the system) the heat storage unit can still be heated (i.e. T _1Q <T _T ). If the check returns a YES result, then the cabin will not form a part of the system, while in the opposite case it will form a part thereof.

In case the cabin needs no heating it is checked if the cabin needs cooling utilizing the cabin cooling system. If no cabin heating is required then neither the cabin nor the cabin cooling/heating system is included in the control system; however, if cabin heating is needed then cabin cooling is turned on and the cabin and the cabin cooling/heating system form a separate system.

The case wherein the heat storage unit need not be heated and the battery can be cooled utilizing the cabin is set forth in algorithm segments 2-4, i.e. in Figs. 7-9. First, it is checked if the cabin has to be heated, i.e. whether its temperature is lower than Tc _AB mino- If yes, then the cabin will be included in the system and it is checked if the battery needs further cooling.

If the temperature of the battery is higher than T _Bmaxl and the cabin temperature is lower than Tc _AB mino then algorithm segments 2-3 are executed (Fig. 7-8).

If the cabin needs to be heated, for example due to winter weather conditions, then it is certain that the outside temperature is lower than the cabin temperature so outside air can be utilized for cooling, therefore the heat exchanger is included in the system. Thereafter it has to be checked if the battery needs further cooling, i.e. if its temperature is higher than T _A7hac 2·

If the battery temperature is higher than T _Am ax 2 _> then the heat storage unit has to be turned on and algorithm segment 2 (shown in Fig. 7) is executed. Because the heat storage unit must not be allowed to heat up, it has to be checked if its temperature is higher than T _Tmax2 . If not, then no further cooling is needed. In that case the only unknown parameter is the state of cabin heating. The cabin is already being heated utilizing the battery, if, however the heating demand thereof is greater, i.e. its temperature is not higher than T _ut mini’ then cabin heating has to be turned on (but otherwise it does not need to be turned on).

If the temperature of the heat storage unit is higher than T _Tmax2 , cabin cooling is turned on in order to ensure the appropriate temperature of the heat storage unit. As it has already been established that the cabin needs heating, it is certain that the cabin does not have to be cooled at this point so the cabin is disconnected from the circuit. (The temperature of the heat storage unit must not rise above T _Tmax2 , this is more important than passenger comfort). Thereafter it has to be checked if the outside temperature still allows for cooling, i.e. if it will not “work against” cabin cooling, that is if it is higher than T ₁₀ . If it is higher than that then the heat exchanger is excluded from the system. Finally, either with or without the heat exchanger it is checked if the battery temperature exceeds the critical T _Bmax3 threshold. If the battery temperature is below the critical temperature the battery can continue operation, but if the critical temperature is exceeded, then the battery has to be shut down.

If the battery temperature is not higher than T _Bmax2 , then it does not need further cooling, and algorithm segment 3 (shown in Fig. 8) is executed. In such a case the status of the heat storage unit is checked. If the temperature of the heat storage unit is not higher than T _Tmaxl , then the heat storage unit is not included in the system, if it is higher than that then it has to be checked if the temperature of the heat storage unit is higher than T _Tmax2 . If the temperature is higher than that, cabin cooling is turned on in order to ensure the appropriate temperature of the heat storage unit. As it has already been established that the cabin needs heating, it is certain that the cabin does not have to be cooled at this point so the cabin is disconnected from the circuit. Because the battery has lower cooling demand than the heat storage unit, the battery is disconnected from the system. It has to be checked if the temperature of the outside air still allows for cooling, i.e. if it will not “work against” cabin cooling, that is if it is higher than T ₁₀ . If it is higher than that then the heat exchanger is excluded from the system. If the temperature of the heat storage unit is between T _Tmaxl and T _Tmax2 , then it has to be checked whether the system is able to cool the storage unit. If T _T > T ₁ , then the heat storage unit is included in (forms a part of) the system, otherwise it is not included therein.

If the temperature of the heat storage unit is not higher than T _Tmax2 , then no decision has yet been made on cabin cooling. The cabin is already being heated with the battery, if, however the heating demand thereof is greater, i.e. its temperature is not higher than T _utminl then cabin heating has to be turned on (otherwise it does not have to be turned on).

Because the temperature of the cabin heating is lower than the battery temperature, the cabin heating does not deteriorate the cooling capacity of the cabin. Depending on the particular embodiment, such a system is conceivable wherein in this case the cabin and the cabin heating/cooling system have to be disconnected.

It has to be noted that cooling with the cabin is not of major importance so it can be turned off if so desired by the passengers.

If the battery requires no further cooling in addition to the cooling provided utilizing the cabin, i.e. its temperature is higher than T _Bmax0 but is not higher than T _Bmaxl and the cabin temperature is lower than T _utmin0 then algorithm segment 4 (see Fig. 9) is executed.

The battery requires no further cooling. In such a case the status of the heat storage unit is checked. If the temperature of the heat storage unit is higher than T _TmaxQ then the heat storage unit has to be cooled. If the temperature of the heat storage unit is higher than the temperature value T _t10 then the heat storage unit can be cooled utilizing the cabin (the heat storage unit turns on). If the heat storage unit has further cooling demand - its temperature is higher than T _Tmaxl - then the heat exchanger will also be included in the system for cooling the heat storage unit. (If it is possible to apply the cabin for cooling, i.e. T _ut <T _utmin o _> then it is certain that the outside temperature is lower than the cabin temperature and is also lower than the temperature of the heat storage unit, so the heat storage unit can also be cooled applying the heat exchanger.) If the temperature of the heat storage unit is higher than T _Tmax2 , then the cabin cooling system also takes part in cooling the heat storage unit. As it has already been established that the cabin needs heating, it is certain that the cabin does not have to be cooled at this point so the cabin is disconnected from the circuit. It has to be checked if the outside temperature still allows for cooling, i.e. if it will not “work against” cabin cooling, that is if it is higher than T ₁₀ . If it is higher than that, then the heat exchanger is excluded from the system.

If the heat storage unit cannot be cooled with the cabin, it could still be cooled applying outside air (if so required) and T _T >T _Tmaxl , then the heat storage unit and the heat exchanger are also switched on. (If the battery can be cooled with the cabin, then it is certain that the outside temperature allows applying outside air for cooling the heat storage unit.) Also on this branch it is checked whether the temperature of the heat storage unit is higher than T _Tmax2 , and then execution continues as with the foregoing branch.

If T _T < T _Tmax 2, then the status of the cabin cooling/heating is not yet known, and is checked according to the cabin demand. The cabin is already being heated with the battery; if, however the heating demand thereof is greater, i.e. its temperature is not higher than T _utminl then cabin heating has to be turned on (otherwise it does not have to be turned on). Because the temperature of the cabin heating is lower than the battery temperature, the cabin heating does not deteriorate the cooling capacity of the cabin. (Depending on the particular embodiment, such a system is conceivable wherein in this case the cabin and the cabin heating/cooling system have to be disconnected.)

If the heat storage unit does not have to be heated and the battery has to be cooled, but the battery cannot be cooled utilizing the cabin and the temperature of the battery is lower than T _{Amax l} , algorithm segments 5-7 are executed (see Figs. 10-12).

If T _T >T _Tmaxl , then the heat storage unit has to be cooled so it will be included in the system, and algorithm segment 5 or 6 is executed.

First it is checked if the heat storage unit can be cooled applying outside air. If the temperature of the heat storage unit is greater than the outside temperature, outside air can be utilized for cooling and the heat exchanger is included in the system; algorithm segment 5 (shown in Fig. 10) is executed. It is also checked if the heat storage unit has further cooling demand. If the temperature of the heat storage unit is higher than T _Tmax2 then the cabin cooling system also takes part in cooling the heat storage unit. It has to be checked if the outside temperature still allows for cooling, i.e. if it will not “work against” cabin cooling, that is if it is higher than T ₁₀ . If it is higher than that then the heat exchanger is excluded from the system. Finally, the status of the cabin needs to be checked. The cabin will only be included in the system if it has to be cooled applying cabin cooling. (The user can decide if s/he would like to cool the cabin or use the battery first.)

If the temperature of the heat storage unit is not higher than T _Tmax2 , then the status of the cabin heating/cooling system is not yet known. What is known is that the cabin does not have to be heated, and that it can only be cooled utilizing the cabin cooling, so it is checked if its temperature is higher than T _CABmaxl . If yes, then the cabin cooling turns on and forms a separate system together with the cabin, while otherwise neither the cabin nor the cabin heating/cooling system is included in the system.

If the temperature of the heat storage unit is not greater than the outside temperature, then algorithm segment 6 according to Fig. 11 is executed. It is checked if the heat storage unit has further cooling demand. If the temperature of the heat storage unit is not lower than T _Tmax2 , then the cabin cooling system also takes part in cooling the heat storage unit. Finally, the status of the cabin needs to be checked. The cabin will only be included in the system if it has to be cooled applying cabin cooling. (The user can decide if s/he would like to cool the cabin or use the battery first.)

If the temperature of the heat storage unit is lower than T _Tmax2 , then the status of the cabin heating/cooling system is not yet known. What is known is that the cabin does not have to be heated, and that it can only be cooled utilizing the cabin cooling, so it is checked if its temperature is higher than T _utmaxl . If yes, then the cabin cooling turns on and forms a separate system together with the cabin, while otherwise neither the cabin nor the cabin heating/cooling system is included in the system.

If the cabin cannot be utilised for cooling and the combined cooling demand of the battery and the heat storage unit is lower than the threshold for turning on the heat exchanger, then algorithm segment 7 (Fig. 12) is executed.

The battery can be operated but it is disconnected from the system; the heat storage unit is also disconnected from the system, so the aspects of the cabin will be investigated.

The cabin does not have to be heated because T _ut >T _utmax0 , so it is checked if the cabin has to be cooled with the cabin cooling, i.e. if T _ut >T _utmaxl (The cabin cannot be cooled by other means.) If the check returns a YES result, then cabin cooling is turned on, otherwise it is left in the off state.

If the cabin does not have to be cooled, then the only component that can be in operation is the battery; however, because it has already been established that the cabin does not have to be heated either, the battery is disconnected from the system.

If the temperature of the battery is not lower than T _Amaxl , then the heat storage unit and the cabin do not have to be cooled; and if the temperature of outside air is lower than T ₁₀ then the battery can be cooled utilizing the heat exchanger, i.e. the heat exchanger will be included in the system and algorithm segments 8-9 (Figs. 13-14) are executed.

First, it has to be checked if the battery has higher cooling demand. If T _A > T _Amax2 , then the heat storage unit will be included in (will form a part of) the system for cooling the battery. In that case the algorithm segment 8 according to Fig. 13 is executed. The status of the heat storage unit is checked. If the temperature of the heat storage unit is higher than T _Tmax2 , cabin cooling is turned on in order to ensure the appropriate temperature of the heat storage unit. Thereafter it has to be checked if the outside temperature still allows for cooling, i.e. if it will not “work against” cabin cooling, that is, if it is higher than T ₁₀ . If it is higher than that, then the heat exchanger is excluded from the system. Finally, either with or without applying the heat exchanger it is checked if the battery temperature exceeds the critical T _Bmax3 threshold. If the battery temperature is below the critical temperature, the battery can continue operation but if the critical temperature is exceeded, then the battery has to be shut down. Subsequently the status of the cabin needs to be checked. The cabin will only be included in the system if it has to be cooled applying cabin cooling. (The user can decide if s/he would like to cool the cabin or use the battery first.)

If the temperature of the heat storage unit is not higher than T _Tmax2 , then the status of the cabin has to be checked. What is known is that the cabin does not have to be heated, and that it can only be cooled utilizing the cabin cooling, so it is checked if its temperature is higher than Tutmaxi- If yes, then the cabin cooling turns on and forms a separate system together with the cabin, while otherwise neither the cabin nor the cabin heating/cooling system is included in the system.

If the battery temperature is not higher than T _Bmax2 , then it does not need further cooling, and algorithm segment 9 (shown in Fig. 14) is executed. In such a case the status of the heat storage unit is checked. If the temperature of the heat storage unit is higher than T _Tmax2 , then the cabin cooling is turned on. Because the battery currently has lower cooling demand than the heat storage unit, the battery is disconnected from the system. It is checked if the outside temperature still allows for cooling, i.e. if it will not “work against” cabin cooling, that is, if it is higher than T ₁₀ . If it is higher than that, then the heat exchanger is excluded from the system. Cabin cooling is included in (forms a part of) the system, so the cabin will only be included in the system if it has to be cooled applying the cabin cooling. (The user can decide if s/he would like to cool the cabin or use the battery first.)

If the temperature of the heat storage unit is between T _Tmaxl and T _Tmax2 , then it is checked if the temperature of the heat storage unit is higher than the temperature value T ₁₄ . If it is higher than this threshold value, then the heat storage unit can be cooled, so it will be included in the system; in the opposite case, or if the temperature of the heat storage unit is not greater than T _Tmaxl , the heat storage unit will not form a part of the system.

Finally, the status of the cabin needs to be checked. What is known is that the cabin does not have to be heated, and that it can only be cooled utilizing the cabin cooling, so it is checked if its temperature is higher than T _ut maxi· If yes, then the cabin cooling turns on and forms a separate system together with the cabin, while otherwise neither the cabin nor the cabin heating/cooling system is included in the system.

If the temperature of the battery is not lower than T _Amaxl , the heat storage unit and the cabin do not require cooling, and the temperature of outside air is not lower than T ₁₀ , then it is not possible to apply the heat exchanger for cooling, i.e. the heat exchanger will not be included in the system and algorithm segments 10-11 (see Figs. 15-16) are executed.

First, it has to be checked if the battery has higher cooling demand. If T _A >T _Amax2 , then the heat storage unit will be included in the system for cooling the battery, and algorithm segment 10 shown in Fig. 15 is executed. Then, the status of the heat storage unit is checked. If the temperature of the heat storage unit is higher than T _Tmax2 , cabin cooling is turned on in order to ensure the appropriate temperature of the heat storage unit. It is then checked if the battery temperature exceeds the critical T _Bmax3 threshold value. If the battery temperature does not exceed the critical threshold value, the battery can continue operation but if the critical temperature is exceeded, the battery has to be shut down. Cabin cooling is included in (forms a part of) the system, so the cabin will only be included in the system if it has to be cooled applying the cabin cooling. If the temperature of the heat storage unit is not higher than T _Tmax2 , then the status of the cabin has to be checked. It is known that the cabin does not have to be heated, and that it can only be cooled utilizing the cabin cooling, so it is checked if its temperature is higher than T _u tmaxi- If yes, then the cabin cooling turns on and forms a separate system together with the cabin, while otherwise neither the cabin nor the cabin heating/cooling system is included in the system.

If the battery temperature is not higher than T _Amax2 , then it does not need further cooling, so it is disconnected from the system and algorithm segment 11 (shown in Fig. 16) is executed. The status of the heat storage unit is checked. If the temperature of the heat storage unit is not lower than T _Tmax2 , then cabin cooling is turned on in order to ensure the appropriate temperature of the heat storage unit. Finally, the status of the cabin needs to be checked. In case the cabin cooling is included in the system, the cabin will only be included in the system if it has to be cooled applying cabin cooling. (The user can decide if s/he would like to cool the cabin or use the battery first.) If the status of the cabin heating/cooling system is not yet known, then it is still known that the cabin does not have to be heated, and that it can only be cooled utilizing the cabin cooling, so it is checked if its temperature is higher than T _Tmaxl . If yes, then the cabin cooling turns on and forms a separate system together with the cabin, while otherwise neither the cabin nor the cabin heating/cooling system is included in the system.

If the battery does not require heating or cooling, then the heating/cooling demand of the heat storage unit is checked. In case the heat storage unit requires cooling and the cabin needs to be heated, the cabin will be included in the system because it can be utilized for cooling the heat storage unit. In such a case algorithm segment 12 (see Fig. 17) is executed.

If the heat storage unit has further cooling demand - its temperature is higher than T _T maxi - then the heat exchanger will also be included in the system for cooling the heat storage unit. If the temperature of the heat storage unit is higher than T _Tmax2 , then the cabin cooling system also takes part in cooling the heat storage unit. As it has already been established that the cabin needs heating, it is certain that the cabin does not have to be cooled at this point so the cabin is disconnected from the circuit. It has to be checked if the outside temperature still allows for cooling, i.e. if it will not “work against” cabin cooling, that is if it is higher than T ₁₀ . If it is higher than that, then the heat exchanger is excluded from the system. If T _t £ T _Tmax2 , then the status of the cabin cooling/heating is not yet known, and is checked according to the cabin demand. The cabin is already being heated with the heat storage unit; if, however the heating demand thereof is greater, i.e. its temperature is lower than Tc _AB mini _> then cabin heating has to be turned on. In such a case a further check has to be performed: it has to be checked if the cabin heating will deteriorate the cooling capability of the cabin. If the temperature T9 measured downstream of the cabin in the control circuit is already higher than the temperature T3 measured downstream of the heat storage unit in the control circuit, then the cabin cannot be utilized for cooling the heat storage unit, so the cabin and the cabin heating/cooling system are disconnected from the main system and are operated separately.

If the battery does not require either heating or cooling and the heat storage unit requires cooling but the heat storage unit cannot be cooled utilizing the cabin, then it has to be checked if the heat storage unit needs “alternative” cooling, i.e. if its temperature exceeds T _Tmaxl , executing algorithm segments 13-15 (see Figs. 18-20).

When the temperature of the heat storage unit is lower than T _Tmaxl , the heat storage unit does not require further cooling, so it will not be included in the system and algorithm segment 13 (Fig. 18) is executed.

Because the battery and the heat storage unit do not have demands that could be fulfilled, the status of the cabin is checked. Based on the foregoing it is known that the cabin does not have to be heated, so in case it has no cooling demand, then everything is disconnected from the system.

If the cabin has cooling demand and T _ut > T _utmaxl , then the cabin cooling turns on (the cabin can only be cooled applying the cabin cooling) and the two systems operate independent from each other.

If the temperature of the heat storage unit is not lower than T _TmaxX , the heat storage unit requires additional cooling, so algorithm segments 14-15 (Fig. 19-20) are executed.

First, it is checked if the heat storage unit can be cooled applying outside air. If the temperature of the heat storage unit is greater than the outside temperature, outside air can be utilized for cooling, and the heat exchanger is included in the system, algorithm segment 14 (shown in Fig. 19) is executed. It is then checked if the heat storage unit has further cooling demand. If the temperature of the heat storage unit is higher than T _Tmax2 then the cabin cooling system also takes part in cooling the heat storage unit.

It has to be checked if the outside temperature still allows for cooling, i.e. if it will not “work against” cabin cooling, i.e. if it is higher than T ₁₀ . If it is higher than that, then the heat exchanger is excluded from the system. It is known that the cabin does not have to be heated, and that it can only be cooled utilizing the cabin cooling, so it is checked if its temperature is higher than T'cABmax _l · If the result of the check is YES, then the cabin will form a part of the system, while in the opposite case it will be excluded therefrom.

If the temperature of the heat storage unit is not higher than T _Tmax2 , then the status of the cabin has to be checked. It is known that the cabin does not have to be heated, and that it can only be cooled utilizing the cabin cooling, so it is checked if its temperature is higher than T _utmaxl . If yes, then the cabin cooling turns on and forms a separate system together with the cabin, while otherwise neither the cabin nor the cabin heating/cooling system is included in the system.

If the temperature of the heat storage unit is not greater than the outside temperature, then algorithm segment 15 according to Fig. 20 is executed. It is checked if the heat storage unit has further cooling demand. If the temperature of the heat storage unit is not lower than T _Tmax2 , then the cabin cooling system also takes part in cooling the heat storage unit. The cabin does not have to be heated, and it can only be cooled utilizing the cabin cooling, so it is checked if its temperature is higher than T _utmaxl, If the result of the check is YES, then the cabin will form a part of the system, while in the opposite case it will be excluded therefrom.

If the temperature of the heat storage unit is lower than T _Tmax2 , then the status of the cabin has to be checked. It is known that the cabin does not have to be heated, and that it can only be cooled utilizing the cabin cooling, so it is checked if its temperature is higher than Tutmax _l - If yes, then the cabin cooling turns on and forms a separate system together with the cabin, while otherwise neither the cabin nor the cabin heating/cooling system is included in the system.

In a further case, when neither the battery nor the heat storage unit requires either cooling or heating, then the heat storage unit is not included in the circuit and the algorithm segment 16 (see Fig. 21) is executed. Became the battery and the heat storage unit do not have demands that could be fulfilled, the status of the cabin is checked. Since the heat storage unit and the battery are not included in the system, and the cabin cannot be heated or cooled applying the heat exchanger, the only condition that has to be checked is whether the cabin cooling/heating system has to be turned on. If T _ut > T _utmaxl , then cabin cooling is turned on. If not, and T _ut < T _utminl , then cabin heating is turned on. If the cabin heating/cooling system is turned on, then the two systems operate independent of each other.

If the cabin does not need either heating or cooling, then nothing is included in the circuit and the circuit is not operated.

If the battery does not require either heating or cooling and the temperature of the heat storage unit is not higher than T _Tmin0 , then the heat storage unit requires heating, and algorithm segment 17 is executed (see Fig. 22).

It is not worth utilizing the cabin heating for heating the heat storage unit because in case the temperature of the battery is too low, cabin heating will directly heat the battery. The temperature of the cabin is always lower than the temperature of the heat storage unit, so the cabin cannot be utilized for heating the heat storage unit (i.e. only outside air can be applied for heating it).

If the outside temperature is higher than the temperature of the heat storage unit, then the heat storage unit and the heat exchanger are both included in the system.

Thereafter the status of the cabin is checked. The cabin is not heated by the heat exchanger, so first it is checked if the cabin has to be heated by the cabin heating. If the check returns a YES result, then the cabin heating turns on and forms a separate system together with the cabin. If cabin heating is not required, then it is checked if the cabin needs cooling. If outside air is utilized for heating the heat storage unit, then it is not possible to apply it for cooling the cabin, while the cabin also cannot be cooled with utilizing the heat storage unit, so it has to be checked straight away if cabin cooling is required. If the check returns a YES result, then the cabin cooling turns on and forms a separate system together with the cabin. In the opposite case neither the cabin nor the cabin cooling/heating system are included in the system.

If the temperature of the battery is lower than T _Amin0 , then the battery has to be heated, and thus algorithm segments 18-19 (see Figs. 23-24) are executed. The battery cannot be heated applying the heat exchanger because in case it requires heating it is certain that the outside temperature is lower. The battery cannot be heated utilizing the cabin because cabin temperature cannot be higher than the temperature of the battery.

When executing this section of the method, it is first checked if the battery can be heated utilizing the heat storage unit. If the check returns a YES result and T _x > T _A , then algorithm segment 18 according to Fig. 22 is executed. The heat storage unit is turned on, and it is checked if the battery requires additional heating. If the check returns a YES result, i.e. T _A < T _Aminl , then cabin heating is turned on and the heat storage unit is switched off (the heat storage unit is not intended to be heated by the cabin heating). Thereafter it has to be checked if the battery temperature is below the critical threshold T _Amjn2 . If it is below the threshold, then the battery must be shut down. After that, the status of the cabin is checked. If the battery has to be heated, then it is certain that the cabin need not be cooled. If the temperature of the cabin is not lower than T _utminl , then the cabin is disconnected; if cabin temperature is lower than that, then the cabin can be connected. In case the battery is not in operation, it is up to the passenger to decide whether s/he would like to heat the cabin or would like to bring the battery back into operation more quickly.

If the battery does not require additional heating (T _A > T _Aminl ), then the status of the cabin heating is not known. It has to be checked if the cabin has any additional heating demand, i.e. if the temperature of the cabin is greater than T _utmin0 . If it is higher than that, then the cabin will not form a part of the system, while in the opposite case it is checked if the cabin has to be heated applying the cabin heating. If the check returns a YES result, then the cabin heating turns on and forms a separate system together with the cabin. If the result is NO, then the cabin is included in the system but the cabin heating will not be turned on.

If the heat storage unit cannot be utilized for heating because T _T < T _A , then algorithm section 19 according to Fig. 24 is executed. Also in this case it is checked if the battery requires additional heating. If the check returns a YES result, then the cabin heating is turned on and it has to be checked if the battery temperature is below the critical threshold T _Bmin2 . If it is below the threshold, then the battery must be shut down. Thereafter it is checked (in both cases) if the cabin has to be heated applying the cabin heating. If the result of the check is YES, then the cabin will form a part of the system, while in the opposite case it will be excluded therefrom. If the battery requires no additional heating _» then the status of the cabin is checked. If the battery has to be heated, then it is certain that the cabin need not be cooled. If the temperature of the cabin is below T _utminl , then the cabin is connected and the cabin heating is turned on and is operated as a separate system; in the opposite case the cabin is disconnected and the cabin heating is turned off.

The temperature values measured in the course of the method are compared, in multiple steps, with the corresponding temperature threshold values, and, depending on the relationship between the compared threshold values, the above described parameters are set based on signals obtained by the compared threshold values, with the heat storage unit, the at least one battery, the at least one external heat exchanger, the at least one cabin, and the cabin heating/cooling system being included in, or excluded from the control circuit based on said signals utilizing control process technology (for example a PLC or other programmable controller), in a manner known per se. Those parameters that have not been modified by the algorithm keep their original values.

The control system carrying out the method is operated when the battery is turned on. In such a case the electric vehicle is not necessarily in operation; for example the system can be turned on a few minutes before the intended time of departure to ensure that the battery and the cabin are at their desired temperature at the time of departure.

Before starting the battery, a timer is applied such that in certain cases the control system can be operated based on the actual (vs the initial) values.

On a number of occasions in the course of the method such a situation may arise wherein the cabin heating/cooling would have to be turned on for passenger comfort, but turning it on would not be preferable from the aspect of the system because the main purpose of the system is battery protection. For example, if battery temperature rises above T _Amax3 , the car will not be able to start until the battery has cooled down. In such situations it is up to the passenger to decide whether it is more important to reach the desired cabin temperature first or to start the car more quickly.

The cabin is not heated and is not cooled utilizing the heat exchanger, because in such cases it is simpler and more economical to apply other cooling methods, for example to open the window.

When comparing temperatures, a system-dependent dT temperature difference has to be taken into account, which difference constitutes the driving force of heat exchange; in an ideal case dT=l°C. List of reference numerals

101 - heat storage unit 102 - battery

104 - cabin

105 - cabin heating/cooling system 103 - cabin heat exchanger

106 - heat exchanger PI - circulator pump

V 1 - motorized directional control valve V3 - motorized directional control valve V4 - motorized directional control valve V9 - motorized directional control valve