Powertrain cooling system for a hybrid vehicle

Abstract

Hybrid vehicle cooling system, with: an internal combustion engine (206); a cooler (209); an electric machine; Power electronic components that can be operated to supply energy to the electric machine; a coolant circuit (220) which is in heat exchange with the internal combustion engine (206), the radiator (209), the electric machine and the power electronics components; wherein the electric machine and the power electronics components are arranged in parallel to each other in the coolant circuit (220) in order to selectively receive coolant from the radiator (209), and wherein the internal combustion engine (206) and the radiator (209) are arranged in series in the coolant circuit (220) and in series with each of the electric machine and the power electronics components, and further comprising an internal combustion engine bypass (226) which is configured to direct the coolant flow around the internal combustion engine (206), and a valve which is operable to selectively direct coolant through the internal combustion engine (206) or through the internal combustion engine bypass (226); a mechanically driven coolant pump (204) to pump coolant through the internal combustion engine (206), wherein the internal combustion engine bypass (226) is further configured to bypass the mechanically driven coolant pump (204), and an electrically driven coolant pump (202) which is operable to circulate coolant through the coolant circuit (220) through the internal combustion engine bypass (226) and through the mechanically driven coolant pump (204) and the internal combustion engine (206), wherein each of the mechanically driven coolant pump (204) and the electrically driven coolant pump (202) is arranged in series with each other and in series with each of the electric machine and the power electronics components in the coolant circuit (220) to provide a coolant flow through the internal combustion engine (206) to the radiator (209) and from the radiator (209) to the electric machine and the power electronics components; and a control unit that can be operated to control the electric machine and the power electronics components in order to supply energy to the electric machine, wherein the control unit is operable to selectively increase the temperature of the internal combustion engine (206) by controlling the electric machine and / or the power electronics components to supply more heat to the coolant which is in heat exchange with the internal combustion engine (206) and by circulating the coolant to the internal combustion engine (206) through at least one of the mechanically driven coolant pumps (204) and the electrically driven coolant pump (202).

Description

background

[0001] The present application relates to a cooling system for a hybrid vehicle and, in particular, but not exclusively, to a powertrain cooling system for a hybrid electric vehicle. A hybrid electric vehicle's powertrain typically receives power for propelling the vehicle from an internal combustion engine and / or an electric drive system. Such a system may comprise several powertrain components, such as an internal combustion engine, one or more motor generators, power electronics components such as one or more inverters or converters, one or more energy storage systems, one or more DC / DC converters, and one or more couplings. These and other hybrid vehicle components can radiate heat and may require cooling.Conventional cooling systems for hybrid vehicles suffer from a number of limitations and problems, including those related to cost, complexity, and performance. There is a need for the special and inventive methods, systems, and devices described herein.

[0002] US Patent 5,251,588 A discloses a control unit for the drive system of a hybrid vehicle. DE 103 00 294 A1 relates to a power transmission thermal management system for a hybrid vehicle with devices for preheating the engine. DE 197 13 804 A1 relates to a device for heating a passenger compartment of a vehicle using the cooling water of a water-cooled engine as a heat source. DE 199 61 825 A1 relates to a cooling / heating circuit for a vehicle with two sub-circuits operating at different temperatures, each containing a radiator to cool a separate component, the sub-circuits being fluidically coupled. DE 101 53 586 A1 relates to a system and a method for controlling cooling for components of a hybrid-powered vehicle. Brief description

[0003] The invention is defined in the independent claims. Advantageous embodiments of the invention are defined in the dependent claims.

[0004] In a first aspect of the invention, a hybrid vehicle cooling system is provided, comprising an internal combustion engine; a radiator; an electric machine; power electronic components capable of supplying energy to the electric machine; and a coolant circuit that exchanges heat with the internal combustion engine, the radiator, the electric machine, and the power electronic components.wherein the electric machine and the power electronics components are arranged in parallel to each other in the coolant circuit in order to selectively receive coolant from the radiator, and wherein the internal combustion engine and the radiator are arranged in series in the coolant circuit and in series with each of the electric machine and the power electronics components, and further comprising an internal combustion engine bypass configured to direct the coolant flow around the internal combustion engine, and a valve operable to selectively direct coolant through the internal combustion engine or through the internal combustion engine bypass;a mechanically driven coolant pump to pump coolant through the internal combustion engine, wherein the internal combustion engine bypass is further configured to bypass the mechanically driven coolant pump, and an electrically driven coolant pump that is operable to circulate coolant through the coolant circuit via the internal combustion engine bypass and through the mechanically driven coolant pump and the internal combustion engine, wherein each of the mechanically driven coolant pump and the electrically driven coolant pump is arranged in series with each other and in series with each of the electric machine and power electronics components in the coolant circuit to provide a coolant flow through the internal combustion engine to the radiator and from the radiator to the electric machine and power electronics components;and a control unit capable of controlling the electric machine and the power electronics components in order to supply energy to the electric machine, wherein the control unit is capable of selectively increasing the temperature of the internal combustion engine by controlling the electric machine and / or the power electronics components to supply more heat to the coolant which is in heat exchange with the internal combustion engine and by circulating the coolant to the internal combustion engine through at least one of the mechanically driven coolant pumps and the electrically driven coolant pump.

[0005] In a further aspect of the invention, a method is provided comprising the steps of: operating an internal combustion engine; pumping a coolant by means of a coolant pump driven by the internal combustion engine up to a coolant flow rate threshold through a closed coolant circuit, which is in heat exchange with the internal combustion engine, a radiator, an electric motor, power electronics components, and an electrically driven coolant pump, wherein the internal combustion engine is arranged in series with the radiator and each of the electric motor and the power electronics components in the coolant circuit, and wherein the electric motor and the power electronics components are arranged in parallel to each other and in series with the electrically driven coolant pump, the coolant pump driven by the internal combustion engine, the internal combustion engine, and the radiator in the coolant circuit; determining an internal combustion engine temperature state;Controlling the operation of the electric motor or power electronics components to increase heat transfer to the coolant for heating the internal combustion engine based on the internal combustion engine temperature condition; and pumping coolant through the internal combustion engine, the radiator, and each of the electric machine and power electronics components through the closed coolant circuit with the internal combustion engine-driven coolant pump in combination with the electrically driven coolant pump, thereby providing an increased coolant flow to the internal combustion engine-driven coolant pump above the coolant flow threshold. Brief description of the drawings Fig. Figure 1 is a schematic diagram depicting a hybrid vehicle drive system with an exemplary cooling system; Fig. Figure 2 is a schematic diagram representing an exemplary cooling system for a hybrid vehicle drive system; and Fig. Figure 3 is a flowchart illustrating an exemplary control procedure for a cooling system for a hybrid vehicle drive system. Detailed description

[0006] For a better understanding of the fundamentals of the invention, reference will now be made to the exemplary embodiments shown in the figures, and technical terms will be used to describe them. It is understood, however, that this does not limit the scope of the invention, and that the invention encompasses and protects such modifications and variations of the illustrated exemplary embodiments and such further applications of the fundamentals of the invention presented here as would normally occur to a person skilled in the art in the field relating to the invention.

[0007] Fig. Figure 1 shows a hybrid vehicle system 100 with an internal combustion engine 102 and a motor-generator 104, which can be selectively connected to each other by a controllable clutch 114. The motor-generator 104 is electrically connected to an electrical energy system 110, which includes one or more power electronic components that can be operated to convert electrical energy received from the motor-generator 104 for storage in a battery and to draw energy from the battery to drive the motor-generator 104. It is understood that the battery can comprise a plurality of devices, for example, a battery bank, a battery pack, as well as ultracapacitors or other energy storage devices. For the sake of simplicity, however, the general term "battery" is used, which is intended to include all these possibilities.Similarly, the power electronics components of the electrical energy system 110 may include one or more buses, inverters, AC / DC converters, DC / DC converters and other power electronics components that can be operated to distribute or convert electrical energy.

[0008] The powertrain of the hybrid vehicle system 100 can be operated in various vehicle drive modes, such that the internal combustion engine 102, the motor-generator 104, or both the internal combustion engine 102 and the motor-generator 104 supply torque to a power transmission 116, via which the torque is supplied to the drive wheels 118 of the hybrid vehicle. The powertrain of the hybrid vehicle system 100 can also be operated such that the internal combustion engine 102 drives the motor-generator 104 to recharge the battery. Furthermore, the powertrain of the hybrid vehicle 100 can be operated in a regenerative braking mode, in which the motor-generator 104 receives torque from the vehicle wheels 118 and generates energy to recharge the battery.It should be clear that the powertrain of the hybrid vehicle system 100 is an exemplary configuration and that other hybrid powertrain configurations are possible in further embodiments, such as series hybrid powertrain configurations, parallel hybrid powertrain configurations, series-parallel hybrid powertrain configurations, and power-split hybrid configurations. It should also be clear that additional torque transmission devices, such as torque converters, gear splitters, differentials, deep reduction gears, and / or other devices, may be arranged in the torque path between the internal combustion engine 102, the motor-generator 104, and the vehicle wheels 118, or at other locations.

[0009] The hybrid vehicle system 100 further comprises a cooling system 120 with a coolant flow path 121 that exchanges heat with the internal combustion engine 102, the clutch 114, the motor-generator 104, and one or more components of the electrical energy system, and is operable to provide heat transfer between these components and the coolant. In exemplary embodiments, the heat exchange is provided by a coolant flow path extending through one or more flow channels formed in a component or component housing. In further exemplary embodiments, heat exchange is provided by a coolant flow path extending through a separate structure that is in contact with a component or its housing.In further exemplary embodiments, heat exchange is provided by a heat transfer device arranged between the coolant flow path and the component or its housing. The coolant flow path 121 is preferably a closed coolant circuit and may have one or more ventilation openings, vent valves, ports, or safety valves; however, some embodiments may also have other types of coolant flow paths. The cooling system 120 further comprises a radiator, a thermostat, and a fan, which can be operated to selectively transfer heat from the coolant flowing through the cooling system 120 to the environment. The cooling system 120 further comprises one or more coolant pumps, which may be electrically or mechanically driven, and may include both an electrically driven and a mechanically driven pump.

[0010] The hybrid vehicle system 100 also includes a control unit 108, which is connected to and operable with the internal combustion engine 102, the motor generator 104, the electrical power system 110, the cooling system 120, and other components and systems of the hybrid vehicle system 100, and is capable of controlling their operation and receiving information from these components or systems or from sensors provided by them. The control unit 108 preferably includes one or more microprocessors, digital storage devices, ASIC circuits, and / or other integrated circuits or logic devices. For the sake of simplicity, the control unit 108 is shown as a single unit; however, it should be clear that multiple control units, control modules, or control module units can be used to perform the control functions described herein.

[0011] Fig. Figure 2 shows an exemplary cooling system 200 for a hybrid vehicle, which is described above in conjunction with Fig. The cooling system 200 is described in section 1 and can be used in the hybrid vehicle system 100 or in other hybrid vehicle systems, such as the alternative and additional systems described herein. The cooling system 200 comprises an electric coolant pump 202 and a mechanical coolant pump 204, which can be operated to pump coolant through a closed coolant circuit 220. The electric coolant pump 202 is driven by electrical energy from an electrical energy system of the hybrid vehicle and is operationally connected to a control unit that controls its operation. The mechanical coolant pump 204 is mechanically driven by a torque from the internal combustion engine 206. In certain operating modes, the cooling system 200 can pump coolant through the coolant circuit 220 solely using the electric coolant pump 202, for example, when the internal combustion engine 206 is switched off.In other operating modes, the cooling system 200 can pump coolant through the coolant circuit 220 solely using the mechanical coolant pump 204, for example, when the internal combustion engine 206 is switched on and the mechanical coolant pump 204 is capable of delivering the desired coolant flow rate. In further operating modes, the cooling system 200 can pump coolant through the coolant circuit 220 using both the electric coolant pump 202 and the mechanical coolant pump 204, for example, when the internal combustion engine 206 is switched on and the desired coolant flow rate requires the use of both the electric coolant pump 202 and the mechanical coolant pump 204.By using multiple operating modes, the cooling system 200 is capable of providing a coolant flow through the closed coolant circuit 220 during all operating modes of the hybrid vehicle, including modes in which the internal combustion engine 206 is switched on or running, and modes in which the internal combustion engine 206 is switched off or stopped.

[0012] In certain exemplary embodiments comprising an electric coolant pump and a mechanical coolant pump, the mechanical coolant pump can be downsized or have a lower delivery capacity relative to the capacity required to provide a desired coolant flow rate or a maximum coolant flow rate required for a cooling system. The coolant pump can thus be sized to reduce parasitic losses of the internal combustion engine. In one exemplary embodiment, the mechanical coolant pump can be configured to meet an average coolant flow rate requirement that is lower than a maximum coolant flow rate requirement.The cooling system can be controlled in such a way that the electric coolant pump can assist the mechanical coolant pump when the coolant flow demand exceeds the average coolant flow demand and the mechanical coolant pump is unable to provide the desired or required coolant flow.

[0013] The cooling system 200 includes controllable valves 203a and 203b, which are operationally connected to a control unit and can be operated to selectively direct a coolant flow either through the internal combustion engine 206 or an internal combustion engine bypass 226. In certain embodiments, a single valve can be operationally connected to a control unit and can be operated to selectively direct a coolant flow either through the internal combustion engine 206 or an internal combustion engine bypass 226. The cooling system 200 also includes a thermostat 205, which can be operated to direct coolant flowing from the internal combustion engine 206 or from the internal combustion engine bypass 226 through the radiator 209 or the radiator bypass 207. The thermostat 205 can be a passive thermostat, e.g., a wax thermostat, or an actively controlled thermostat, e.g., an electrically controlled thermostat.The radiator 209 is capable of transferring heat from the coolant flowing through it to the outside environment, and an electrically driven fan 210, operationally connected to a control unit, is controllable to increase or decrease the heat transfer rate by controlled flow of ambient air over the radiator 209. The radiator 209 is used jointly by all devices and components that transfer heat to the coolant flowing through the coolant circuit 220 and provides heat transfer to the outside environment for all these devices and components. As in . Fig. As shown in Figure 2, these devices comprise the internal combustion engine 206 and hybrid powertrain components 208, which are described in more detail below. It is understood that additional or other hybrid powertrain components can also be cooled by the cooling system 200.

[0014] The cooling system 200 has several valves 224a, 224b, 224c, 224d and 224c (collectively designated by bracket 224) that can be operated to direct a coolant flow to corresponding hybrid powertrain components 208a, 208b, 208c and 208d (collectively designated by bracket 208) and to a hybrid powertrain component bypass 228. The valves 224 can be actively controlled or passive devices, e.g., throttle orifices that passively control the coolant flow to an associated hybrid powertrain component. In the Fig. In the embodiment shown in Figure 2, component 208a is a motor generator, component 208b is an inverter, component 208c is a coupling, and component 208d is a DC / DC converter. It should be clear that in addition to or instead of the components shown, there may be additional or other hybrid powertrain components that generate heat and require cooling. As shown in Figure 2, the following applies: Fig. As shown in Figure 2, the hybrid powertrain components 208 and the hybrid powertrain component bypass 228, together with their associated valves, are arranged parallel to each other with respect to the coolant flow in a closed coolant circuit 220. In further embodiments, other positions for the hybrid powertrain components 208 relative to each other and with respect to the other components of the cooling system 200 are possible, such as a serial flow arrangement in various sequences.

[0015] Fig. Figure 3 shows an exemplary procedure 300, executable by one or more control units, for controlling the operation of a cooling system for a hybrid vehicle system. The hybrid vehicle system can perform the above in conjunction with Fig. The hybrid vehicle system 100 described in section 1, wherein the control unit 108 is configured and operable by software, firmware, hardware, or combinations thereof to execute the procedure 300. The procedure 300 can also be used in conjunction with other hybrid vehicle systems and control units, such as in the alternative and additional systems described herein. The cooling system can perform the above in conjunction with Fig. 2 cooling system 200 described or another cooling system, such as the alternative or additional systems described herein.

[0016] Procedure 300 starts with a valve state determination step 310, in which one or more tests and valve control steps are performed to confirm that one or more controllable valves in the coolant circuit are appropriately positioned for the current operating state of the system, and / or to initiate any necessary readjustments or settings of the controllable valves. The valve control steps may include tests of internal combustion engine operation, coolant temperature, and the temperature of one or more hybrid powertrain components, as well as commands to adjust valves to direct coolant flow to the internal combustion engine or the internal combustion engine bypass, to hybrid powertrain components or the hybrid powertrain component bypass, and / or to the radiator or the radiator bypass (in the case of an actively controlled thermostat). From start step 310, procedure 300 proceeds to condition step 320.

[0017] Condition step 320 checks whether the combustion engine of a hybrid vehicle is switched on. This determination can be made by checking whether the combustion engine is running and / or being started. If condition step 320 determines that the combustion engine is not switched on, procedure 300 proceeds to step 321, in which a pump operating mode I is provided. In pump operating mode I, coolant is circulated using an electric coolant pump. The coolant flow rate provided by the electric coolant pump can be controlled based on the temperature of one or more hybrid powertrain components, the coolant temperature, or other variables to deliver a coolant flow effective in providing the desired cooling of the hybrid powertrain components cooled by the cooling system.

[0018] From step 321, procedure 300 proceeds to condition step 322, which determines whether an internal combustion engine start operation is expected. This determination may be based on output power or torque requirements, such as a driven torque, the state of charge of a battery or electrical storage device, and other variables that determine whether the internal combustion engine will be started to provide torque for vehicle propulsion and / or to charge a battery or other electrical storage device. If condition step 322 determines that an internal combustion engine start operation is expected, procedure 300 proceeds to step 323. In step 323, one or more valves are controlled that are operable to direct a coolant flow through an internal combustion engine or an internal combustion engine bypass to direct a coolant flow through the internal combustion engine.This can involve opening a closed valve to allow coolant to flow through the internal combustion engine, closing an open valve to block coolant flow through an internal combustion engine bypass, adjusting a valve to allow coolant flow through the internal combustion engine, or combinations thereof, as well as valve adjustments. Procedure 300 proceeds from step 323 to condition step 340. If condition step 322 determines that the internal combustion engine start process is not expected, procedure 300 proceeds to condition step 340.

[0019] If condition step 320 determines that the internal combustion engine is running, procedure 300 proceeds to condition step 330. When the internal combustion engine is running, a mechanical coolant pump driven by the engine circulates coolant through a coolant circuit. Condition step 320 determines whether the desired coolant flow rate is greater than the maximum flow rate that can be provided by the mechanical coolant pump. If condition step 320 determines that the desired coolant flow rate is not greater than the maximum flow rate, procedure 300 proceeds to step 332, which provides Pump Operating Mode II. In Pump Operating Mode II, the mechanical coolant pump is used to provide the desired coolant flow rate without operating the electric coolant pump.If condition step 320 determines that the desired coolant flow rate is greater than the maximum coolant flow rate that can be provided by the mechanical coolant pump, procedure 300 proceeds to step 333, which provides a pump operating mode III. In pump operating mode III, an electric coolant pump is operated in conjunction with the mechanical coolant pump to provide the desired coolant flow rate. From steps 332 and 333, procedure 300 proceeds to condition step 340.

[0020] In condition step 340, it is determined whether the combustion engine temperature is lower than a minimum temperature effective in achieving desired operation and / or emissions from the combustion engine. This determination can be based on the coolant temperature, e.g., the temperature at the combustion engine outlet or elsewhere, the engine oil temperature, the temperature of the combustion engine itself, or on measured, recorded, calculated, or determined parameters that indicate the combustion engine temperature.

[0021] If, in condition step 340, it is determined that the combustion engine temperature is lower than a minimum temperature effective in providing desired combustion engine operation and / or emissions, procedure 300 proceeds to step 350. In step 350, increased heating power is provided to the coolant to raise the combustion engine temperature. This can be achieved by activating one or more hybrid powertrain components to increase the amount of radiated heat to a level higher than that actually required for their intended operation, in order to transfer the increased heat to the coolant. In some embodiments, this is achieved by activating a motor-generator with reduced efficiency to transfer additional heat to the coolant flowing to the combustion engine.In other embodiments, additional or different hybrid powertrain components with reduced efficiency can be put into operation to transfer additional heat to the coolant flowing to the combustion engine, such as power electronics components, e.g., inverters or converters. From step 350, procedure 300 jumps back to step 310.

[0022] If, in condition step 340, it is determined that the internal combustion engine temperature is not lower than a minimum temperature effective in providing the desired operation and / or emissions of the internal combustion engine, procedure 300 proceeds to step 360. In step 360, an electric cooling fan is controlled to provide a desired heat transfer rate from the coolant to the environment. From step 360, procedure 300 jumps back to step 310.

[0023] It should be clear that the sequence of steps in the procedure described herein may differ from the embodiments shown. It should further be clear that the logical operations described herein also include the use of functionally analogous or equivalent operations. Therefore, if an operation is performed to determine whether a value is less than a maximum value, an analogous operation may be performed to determine whether the value is greater than a minimum value. Similarly, if "greater than" or "less than" operations are performed, "greater than or equal to" or "less than or equal to" operations may be performed.

[0024] Some exemplary embodiments include cooling systems for hybrid vehicles with a closed coolant circuit comprising at least one valve operable to supply a coolant flow to an internal combustion engine or an internal combustion engine bypass, a thermostat operable to supply the coolant flow from the internal combustion engine or the internal combustion engine bypass to a radiator or a radiator bypass, several hybrid powertrain components arranged in parallel to receive a coolant flow from the radiator or the radiator bypass, a mechanically driven coolant pump operable to pump coolant through the closed coolant circuit, and an electrically driven coolant pump operable to pump coolant through the closed coolant circuit.Certain exemplary embodiments further include a control unit configured to control the system to operate in a first mode in which the internal combustion engine is switched on, the mechanically driven coolant pump is operating to pump coolant through the closed coolant circuit up to a coolant flow rate threshold, and in which the mechanically driven coolant pump and the electrically driven coolant pump are operating to pump coolant through the closed coolant circuit above the coolant flow rate threshold.Certain embodiments further include a control unit configured to operate the system in a second mode in which the internal combustion engine is off, the mechanically driven coolant pump is off, the at least one valve of the internal combustion engine bypass supplies a coolant flow, and the electrically driven coolant pump is operating to pump coolant through the closed coolant circuit. Certain embodiments further include a control unit operable to operate the system in a third mode in which one or more hybrid powertrain components are controlled to heat the coolant and thus warm the internal combustion engine. In certain embodiments, the coolant circuit connects the internal combustion engine or the internal combustion engine bypass in series with the multiple hybrid powertrain components.In certain exemplary embodiments, the multiple hybrid powertrain components comprise a motor-generator, a clutch, and power electronics components. In certain exemplary embodiments, the mechanically driven coolant pump and the electrically driven coolant pump are arranged in series in the coolant circuit between the internal combustion engine and the multiple hybrid powertrain components. Certain exemplary embodiments further feature multiple valves that can be operated to direct a coolant flow from the radiator or from the radiator bypass to corresponding components of the multiple hybrid powertrain or the hybrid powertrain component bypass.In certain exemplary embodiments, the system has a required peak coolant flow rate, and the maximum coolant flow rate provided by the mechanically driven coolant pump is less than the required peak coolant flow rate. In certain exemplary embodiments, the mechanically driven coolant pump can be operated to pump coolant through the internal combustion engine, and the electrically driven coolant pump can be operated to pump coolant through the internal combustion engine or the internal combustion engine bypass. In certain exemplary embodiments, the coolant flow passes sequentially from the mechanically driven coolant pump or from the electrically driven coolant pump to the internal combustion engine or the internal combustion engine bypass, to the various hybrid powertrain components, and back to the mechanically driven coolant pump or the electrically driven coolant pump.

[0025] Some exemplary embodiments include hybrid vehicle systems comprising an internal combustion engine, an electric machine, power electronics components operable to supply power to the electric machine, a coolant circuit in heat exchange with the internal combustion engine, the electric machine and the power electronics components, and a control unit operable to control the electric machine and the power electronics components to supply power to the electric machine, wherein the control unit is operable to selectively increase the temperature of the internal combustion engine by controlling the electric machine and / or the power electronics components to supply more heat to the coolant.In certain exemplary embodiments, the control unit can be operated to selectively activate an electric coolant pump to increase the coolant flow rate provided by a mechanical coolant pump driven by the internal combustion engine. In certain exemplary embodiments, the control unit can be operated to route the coolant around the internal combustion engine via a bypass. In certain exemplary embodiments, the coolant flow to the electric machine and the power electronics components is in parallel. Certain exemplary embodiments further include a radiator, with the coolant circuit running in series through the internal combustion engine, the radiator, and the electric machine and / or the power electronics components. In certain exemplary embodiments, the electric machine includes a motor generator.

[0026] Some exemplary embodiments include methods that involve pumping a coolant through a closed coolant circuit that exchanges heat with an internal combustion engine, an electric motor, and power electronics components; determining an internal combustion engine temperature state; and controlling the operation of the electric motor and power electronics components to increase heat transfer to the coolant for heating the internal combustion engine based on that temperature state. In certain exemplary embodiments, controlling the operation of the electric motor or power electronics components to increase heat transfer to the coolant for heating the internal combustion engine includes controlling the electric motor or power electronics components to operate at reduced efficiency.Certain exemplary embodiments further include operating the internal combustion engine, pumping coolant through a closed coolant circuit by means of a coolant pump driven by an internal combustion engine up to a coolant flow rate threshold, and pumping coolant through the closed coolant circuit by means of the coolant pump driven by the internal combustion engine in combination with an additional coolant pump above the coolant flow rate threshold. Certain exemplary embodiments further include controlling a valve for selectively directing a coolant flow through the internal combustion engine or through an internal combustion engine bypass.Certain exemplary embodiments further include pumping coolant through the closed coolant circuit by means of an electrically driven coolant pump and routing coolant around the internal combustion engine via a bypass while the internal combustion engine is switched off. Certain exemplary embodiments further include selectively cooling the coolant by transferring heat from the coolant by means of a radiator.

[0027] Although the invention has been precisely illustrated and described in the figures and the preceding description, the latter is to be regarded as explanatory and not limiting, and it is understood that only certain exemplary embodiments have been shown and described, and that all modifications and adaptations that are in keeping with the spirit of the invention are to be protected. When reading the claims, the use of words such as "a," "an," "at least a," or "at least a section" does not intend to limit the claim to only one element, unless expressly stated otherwise in the claim. When the phrase "at least a section" and / or "a section" is used, the subject matter may comprise part and / or all of the subject matter, unless expressly stated otherwise. Reference symbol list 100 System / Hybrid vehicle system 102 Internal combustion engine 104 Motor generator 108 Control unit 110 Energy system 114 Clutch 116 Power transmission 118 Drive wheel / vehicle wheel 120 Cooling system 121 Coolant flow path 200 cooling system 202 electric coolant pump 203a controllable valve 203b controllable valve 204 mechanical coolant pump 205 Thermostat 206 Internal combustion engine 207 Cooler bypass 208 Hybrid Powertrain Components 208a Motor generator 208b Inverter 208c clutch 208d DC / DC converter 209 coolers 210 blowers 220 closed coolant circuit 224a Valve 224b valve 224c valve 224d valve 224e valve 226 Internal combustion engine bypass 228 hybrid powertrain component bypass 300 exemplary procedures 310 Valve status determination step 320 Condition step 321 steps 322 Condition step Step 323 330 Condition step 332 steps Step 333 340 Condition step 350 steps 360 steps

Claims

[1] Hybrid vehicle cooling system, with: an internal combustion engine (206); a cooler (209); an electric machine; Power electronic components that can be operated to supply energy to the electric machine; a coolant circuit (220) which is in heat exchange with the internal combustion engine (206), the radiator (209), the electric machine and the power electronics components; wherein the electric machine and the power electronics components are arranged in parallel to each other in the coolant circuit (220) in order to selectively receive coolant from the radiator (209), and wherein the internal combustion engine (206) and the radiator (209) are arranged in series in the coolant circuit (220) and in series with each of the electric machine and the power electronics components, and further comprising an internal combustion engine bypass (226) which is configured to direct the coolant flow around the internal combustion engine (206), and a valve which is operable to selectively direct coolant through the internal combustion engine (206) or through the internal combustion engine bypass (226); a mechanically driven coolant pump (204) to pump coolant through the internal combustion engine (206), wherein the internal combustion engine bypass (226) is further configured to bypass the mechanically driven coolant pump (204), and an electrically driven coolant pump (202) which is operable to circulate coolant through the coolant circuit (220) through the internal combustion engine bypass (226) and through the mechanically driven coolant pump (204) and the internal combustion engine (206), wherein each of the mechanically driven coolant pump (204) and the electrically driven coolant pump (202) is arranged in series with each other and in series with each of the electric machine and the power electronics components in the coolant circuit (220) to provide a coolant flow through the internal combustion engine (206) to the radiator (209) and from the radiator (209) to the electric machine and the power electronics components; and a control unit that can be operated to control the electric machine and the power electronics components in order to supply energy to the electric machine, wherein the control unit is operable to selectively increase the temperature of the internal combustion engine (206) by controlling the electric machine and / or the power electronics components to supply more heat to the coolant which is in heat exchange with the internal combustion engine (206) and by circulating the coolant to the internal combustion engine (206) through at least one of the mechanically driven coolant pumps (204) and the electrically driven coolant pump (202). [2] Hybrid vehicle cooling system according to claim 1, wherein the control unit is operable to selectively activate the electrically driven coolant pump (202) in order to increase the coolant flow rate provided by the coolant pump (204) mechanically driven by the internal combustion engine (206). [3] Hybrid vehicle cooling system according to claim 1, wherein the control unit is operable to selectively direct the coolant to the combustion engine bypass (226) in order to direct the coolant around the mechanically driven coolant pump (204) and the combustion engine (206). [4] Hybrid vehicle cooling system according to claim 1, wherein the electric machine comprises a motor generator. [5] Procedure with the steps: Operating an internal combustion engine (206) Pumping a coolant by means of a coolant pump (204) driven by the internal combustion engine (206) up to a coolant flow rate threshold through a closed coolant circuit (220) which is in heat exchange with the internal combustion engine (206), a radiator (209), an electric motor, power electronics components, and an electrically driven coolant pump (202), wherein the internal combustion engine (206) is arranged in series with the radiator (209) and each of the electric motor and the power electronics components in the coolant circuit (220), and wherein the electric motor and the power electronics components are arranged in parallel to each other and in series with the electrically driven coolant pump (204), the coolant pump (204) driven by the internal combustion engine (206), the internal combustion engine (206), and the radiator (209) in the coolant circuit (220); Determining the temperature state of an internal combustion engine; Controlling the operation of the electric motor or power electronics components to increase heat transfer to the coolant for heating the combustion engine based on the combustion engine temperature condition; and Pumping of coolant through the internal combustion engine (206), the radiator (209), and each of the electric machine and power electronics components through the closed coolant circuit (220) with the coolant pump (204) driven by the internal combustion engine (206) in combination with the electrically driven coolant pump (202), thereby providing an increased coolant flow to the coolant pump (204) driven by the internal combustion engine (206) above the coolant flow threshold. [6] Method according to claim 5, wherein controlling the operation of the electric motor or the power electronics components to increase the heat transfer to the coolant for heating the internal combustion engine (206) comprises controlling the electric motor or the power electronics components in such a way that the amount of heat radiated onto the coolant is increased by operating the electric motor or the power electronics components with reduced efficiency while still meeting the power demand. [7] Method according to claim 5, comprising controlling a valve for selectively directing a coolant flow through the internal combustion engine (206) or through an internal combustion engine bypass (226). [8] Method according to claim 5, comprising pumping coolant through the closed coolant circuit by means of an electrically driven coolant pump (202) and directing coolant around the internal combustion engine (206) while the internal combustion engine (206) is switched off. [9] Method according to claim 5, comprising selective cooling of the coolant by transferring heat from the coolant by means of the cooler (209).

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