INTEGRATED POWER ELECTRONICS AS WELL AS SYSTEM AND METHOD FOR THE THERMAL CONTROL OF THE INTAKE AIR

Abstract

A comprehensive thermal management system: a drive system (100) comprising an internal combustion engine (110) and an electric machine (114, 116); a power electronics system (147) from which the electrical power is supplied to the electrical machine (114, 116); a liquid circuit (280) designed to cool the power electronics system (147); an intake air heat exchanger (166) through which the intake air of the internal combustion engine (110) is circulated; and a controller (210) configured to operate the fluid circuit (280) to collect heat from the power electronics system (147) and selectively transfer the heat to the intake air heat exchanger (166), wherein the controller (210) is configured to calculate a water content limit of the intake air and estimate a water content of the intake air, wherein the controller (210) is configured to compare the estimated water content with the calculated water content limit to determine whether the intake air should be heated or cooled, wherein the controller (210) is configured to estimate a target temperature of the intake air and determine whether the target temperature has been reached after transferring the heat to the intake air heat exchanger (166).

Description

INTRODUCTION

[0001] The present disclosure relates generally to thermal management and in particular to the integration of the power electronics with a heat exchanger arranged in an intake air system to control the heating and cooling of the intake air.

[0002] A wide variety of systems process multiple working fluids to achieve desired results. One application involves internal combustion engines, such as those used in automobiles, which process intake air and fuel in one or more combustion chambers. The processing of the working fluid in a combustion chamber generates heat and exhaust gases. This heat can be dissipated from the system by an engine cooling system. Some internal combustion engines may also include a supercharging system with a compressor designed to increase the pressure of the combustion air supplied to the engine. The compressors operate at high speeds and generate heat, which can be extracted from the intake air by an intercooler. Electric motors for propulsion are also among the many applications.These machines are typically connected to a control system that uses power electronic devices, such as in a traction current converter module.

[0003] Under certain operating conditions of the internal combustion engine, water carried along in the intake air can condense undesirably before reaching the engine cylinders. This occurs at temperatures below freezing and especially when the engine is cold and the intake manifold pressure is higher than ambient pressure. The accumulation of water in liquid or solid form is undesirable.

[0004] DE 10 2014 226 018 A1 describes a motor vehicle with an internal combustion engine, with a high-temperature cooling circuit and with an electric machine, which has at least one component that can be cooled by a coolant circuit, characterized in that the coolant circuit by which the at least one component can be cooled is a low-temperature cooling circuit.

[0005] US 2014 / 0299112A1 describes a method and a system for heating and cooling the charge air in an intake system via a compressor coolant channel, in order to reduce condensation and increase charge air cooling. Potential heat sources for the low-temperature circuit include the high-temperature engine cooling circuit and exhaust gases. A shut-off element located in a bypass line around the heat exchanger can be adjusted to control the supply in response to the charge air temperature.

[0006] WO 2019 / 039 990 A1 describes a turbocharged internal combustion engine with at least one intake line belonging to an intake system for supplying the internal combustion engine with charge air, at least one exhaust line belonging to an exhaust system for discharging the exhaust gases, at least one compressor arranged in the at least one intake line, which comprises at least one impeller mounted on a rotatable shaft and a housing in which this at least one impeller is arranged, wherein the compressor is equipped with liquid cooling, for which purpose the housing has at least one integrated coolant channel, and an exhaust gas recirculation system, the return line of which branches off from the exhaust system and opens upstream of the compressor into the intake system.

[0007] DE 10 2013 224 393 A1 describes methods and systems for supplying additional heat to an intercooler to reduce condensation. A coolant valve can control the supply of heated engine coolant to the inlet side of the intercooler. The coolant valve can be adjusted based on the amount of condensation in the intercooler and the temperature at the intercooler outlet.

[0008] It is desirable to provide systems and methods that effectively prevent the accumulation of water in an inlet system. Furthermore, other desirable features and characteristics of the present invention will become apparent from the following detailed description and the attached claims, which were included in conjunction with the attached figures and the preceding technical description and introduction. DESCRIPTION

[0009] Systems and methods for preventing condensation of the intake air are provided. According to the invention, a thermal management system comprises a drive system with an internal combustion engine and an electric machine. A power electronics system supplies the electric machine with current. A fluid circuit is configured to cool the power electronics system. The intake air of the internal combustion engine is circulated through an intake air heat exchanger.A controller regulates the fluid circuit to collect heat from the power electronics system and selectively transfer this heat to the intake air heat exchanger, wherein the controller is configured to calculate a water content limit of the intake air and estimate a water content of the intake air, wherein the controller is configured to compare the estimated water content with the calculated water content limit to determine whether the intake air should be heated or cooled, wherein the controller is configured to estimate a target temperature of the intake air and determine whether the target temperature has been reached after transferring the heat to the intake air heat exchanger.

[0010] In other embodiments, the flaps control the airflow above the radiator, and the control system is designed to actuate the flaps.

[0011] In further embodiments, a pump and a flow control valve are arranged in the liquid circuit. The control system is configured to actuate the pump and the flow control valve in response to the water content in the intake air.

[0012] In further embodiments, the control system is configured to initiate a heating operating mode when the water content in the intake air exceeds a saturation point of the intake air.

[0013] In further embodiments, the control system is configured to initiate a cooling operating mode when the water content in the intake air is less than a saturation point of the intake air.

[0014] In further embodiments, the control system is configured to estimate the water content in the intake air by evaluating an exhaust gas recirculation component of the intake air, a positive crankcase ventilation component of the intake air, a fresh air component of the intake air, and a residual gas component of the intake air.

[0015] In further embodiments, an intake duct supplies the intake air to the combustion engine. A compressor is arranged in the intake duct to charge the intake air. The control system is configured to operate the liquid circuit for cooling the intake air when the compressor is running to charge the intake air.

[0016] According to the invention, a method for controlling a thermal management system comprises supplying power to an electric machine of a drive system via a power electronic system. The power electronic system is cooled by a liquid circuit. The intake air of the combustion engine is circulated through an intake air heat exchanger.A controller regulates the fluid circuit to collect heat from the power electronics system and selectively transfer this heat to the intake air heat exchanger, wherein the controller is configured to calculate a water content limit of the intake air and estimate a water content of the intake air, wherein the controller is configured to compare the estimated water content with the calculated water content limit to determine whether the intake air should be heated or cooled, wherein the controller is configured to estimate a target temperature of the intake air and determine whether the target temperature has been reached after transferring the heat to the intake air heat exchanger.

[0017] In other embodiments, flaps actuated by the control unit regulate the airflow over the cooler.

[0018] In further embodiments, a pump circulates fluid in the fluid circuit, and a flow control valve regulates the flow in the fluid circuit. The control system regulates the pump and the flow control valve in response to the water content in the intake air.

[0019] In further embodiments, the control system initiates a heating operating mode when the water content in the intake air exceeds a saturation point of the intake air.

[0020] In further embodiments, the control system initiates a cooling operating mode when the water content in the intake air is less than a saturation point of the intake air.

[0021] In further embodiments, the control system is configured to estimate the water content in the intake air by evaluating an exhaust gas recirculation component of the intake air, a positive crankcase ventilation component of the intake air, a fresh air component of the intake air, and a residual gas component of the intake air.

[0022] In several other embodiments, a drive system comprises an internal combustion engine and an electric machine. A power electronics system supplies power to the electric machine. A fluid circuit cools the power electronics system. The intake air from the internal combustion engine is recirculated through an intake air heat exchanger. A control unit is configured to read inputs from an intake manifold pressure and temperature sensor and an intake port pressure sensor. Based on these inputs, the control unit determines a limit value for the water content of the intake air and estimates the water content by evaluating an exhaust gas recirculation component of the intake air, a positive crankcase ventilation component of the intake air, a fresh air component of the intake air, and a residual gas component of the intake air.The liquid circuit has the task of cooling the intake air when the estimated water content is below the water content limit, and of heating the intake air when the estimated water content is above the water content limit. BRIEF DESCRIPTION OF THE FIGURES

[0023] The exemplary embodiments are described below in conjunction with the following figures, where similar reference numerals denote similar elements, and where Fig. Figure 1 illustrates a thermal management system in conjunction with a drive system with power electronics according to various embodiments; Fig. 2 is section 2-2 of the internal combustion engine of the system of Fig. 1; Fig. Figure 3 is a data flow diagram illustrating control aspects of a thermal management system in accordance with various embodiments; and Fig. Figure 4 is a flowchart of methods for controlling the thermal management system in accordance with different embodiments. DETAILED DESCRIPTION

[0024] The following detailed description is merely exemplary and is not intended to restrict application and use. Furthermore, it is not intended to be bound by any explicit or implicit theory presented in the preceding technical section, background information, summary, or detailed description below.In the form used herein, the term module refers to any hardware, software, firmware, electronic control component, processing logic and / or processor device, individually or in any combination, including but not limited to: application-specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated or group) and memory executing one or more software or firmware programs, a combinational logic circuit and / or other suitable components providing the described functionality.

[0025] Embodiments of the present disclosure can be described herein in the form of functional and / or logical block components and various processing steps. It should be noted that such block components can be implemented by any number of hardware, software, and / or firmware components configured to perform the specified functions. For example, an embodiment of the present disclosure may employ various integrated circuit components, such as memory elements, digital signal processing elements, logic elements, lookup tables, or the like, which can perform a variety of functions under the control of one or more microprocessors or other control devices.Furthermore, those who are familiar with this field will appreciate that embodiments of the present disclosure can be practiced in conjunction with any number of steering systems and that the vehicle system described herein is only an exemplary embodiment of the present disclosure.

[0026] For the sake of brevity, conventional techniques relating to signal processing, data transmission, signaling, control, and other functional aspects of the systems (and the individual operating components of the systems) are not described in detail here. Furthermore, the connecting lines shown in the various figures are intended to represent exemplary functional relationships and / or physical couplings between the various elements. It should be noted that many alternative or additional functional relationships or physical connections may exist in an embodiment of this disclosure.

[0027] As described here, in the disclosed system and process embodiments, excess heat from an electrical system is used to heat the intake air under certain conditions. A number of embodiments generally include a hybrid drive system with an internal combustion engine and an electric motor. A power electronics system is provided for supplying power to the electric motor. A thermal management system encompasses several aspects of the drive system and includes a fluid circuit designed to cool the power electronics system. A heat exchanger is configured to cool the intake air of the internal combustion engine.A control system is configured to calculate a limit value for the water content of the intake air, estimates the water content of the intake air, and operates the thermal management system to collect heat from the power electronics system and selectively transfer it to the heat exchanger to warm the intake air. Warming the intake air is desirable under certain operating conditions where there is a risk of condensation.

[0028] One embodiment may include a drive system 100, as shown in Fig. 1 shown, which has an internal combustion engine 110, also in Fig. Figure 2 shows an electrified transmission 112 comprising a pair of electric machines configured as motors 114 and 116. It is advantageous that the motors 114 and 116 can also operate as generators. In other embodiments, the electrification can take a different form, for example, by a separate electric motor or an electric motor integrated into the motor 110. In this embodiment, the motor 110 generally has an engine block 120 defining at least one cylinder 124, each of which has a piston 125 coupled to rotate a crankshaft 126. A cylinder head 130 works in conjunction with each of the pistons 125 to define a combustion chamber 132. A fuel-air mixture (not shown) is fed into the combustion chamber 132 and ignited, resulting in hot, expanding exhaust gases that cause a reciprocating motion of the piston(s) 125.Fuel is supplied by at least one fuel injector 136, and air is supplied through at least one inlet port 138. The fuel is supplied to the fuel injector(s) 136 under high pressure from a fuel rail 140 in fluid communication with a high-pressure fuel pump 142, which increases the pressure of the fuel received from a fuel source 144. Each of the cylinders 124 has at least two valves 146, which are actuated by a camshaft 148 that rotates in time with the crankshaft 126. The valves 146 selectively allow air from port 138 into the combustion chamber 132 and alternately allow exhaust gases to exit through port 150. In some examples, a camshaft adjuster can selectively vary the valve timing between the camshaft 148 and the crankshaft 126.

[0029] The intake air can be distributed to the air inlet(s) 138 via an intake manifold 154. An air inlet duct system 156 supplies air from the environment through an inlet 158 ​​to supply the intake manifold 154. A forced air system, such as a charging system 160 with a compressor 162 rotaryally coupled to a turbine 164, can be provided. The turbine 164 rotates by receiving exhaust gases from an exhaust manifold 168, which directs the exhaust gases from the outlet openings 150 and through a series of guide vanes before they expand through the turbine 164. The exhaust gases leave the turbine 164, are routed through an exhaust system 165 to an aftertreatment system 170, and discharged through an exhaust pipe 172. The rotation of the compressor 162 increases the pressure and temperature of the air in the intake duct system 156 and in the intake manifold 154.An intercooler in the form of a heat exchanger 166 is arranged in the intake duct system 156 and can operate alternately, as described below, to decrease the temperature of the intake air or to increase the temperature of the intake air.

[0030] The current embodiment includes a positive crankcase ventilation (PCV) system 176, which is coupled between the crankcase 182 and the intake manifold system 156. A PCV valve 177 regulates the flow through the PCV system 176. An exhaust gas recirculation (EGR) system 184 is coupled between the exhaust system 165 and the intake manifold 154. The EGR system 184 of this embodiment is a low-pressure system that draws in exhaust gas downstream of the turbine 164. Other embodiments may include a high-pressure EGR system (not shown) that draws in exhaust gas upstream of the turbine 164, either in addition to or separately from the low-pressure EGR system 184. An EGR valve 186 regulates the exhaust gas flow in the EGR system 184.

[0031] In general, the combustion air entering cylinder 124 is a combination of ambient air entering through inlet 158, exhaust gases recirculated through the EGR system 184, and crankcase gases drawn in through the PCV system 176. Additionally, a residual gas fraction remains in the intake manifold 154. Consequently, the air in the intake manifold 154 has a water content that is a combination of contributions from these sources. Part of the water content can originate from ambient air, EGR gases, PCV gases, and residual gas, respectively. Under certain conditions, for example, when the air is saturated, water can condense in the intake duct system 156 and / or the intake manifold 154. For example, condensation can form during a cold start of the engine 110, especially at sub-zero ambient temperatures. Furthermore, ice can form from the condensation.These undesirable results are addressed, as described here, by the disclosed systems and methods that advantageously avoid condensation.

[0032] The drive system 100 also includes a control system 200, which typically consists of a controller 210, a power electronics system 147, a battery system 214, and a sensor system 216. The sensor system 216 comprises one or more sensor devices that detect observable states of the drive system 100. In this version, the sensor devices include, among others, an intake manifold pressure sensor 218, an air mass flow and temperature sensor 220, a manifold pressure and temperature sensor 222, a PCV pressure sensor 215, coolant and oil temperature and level sensors 226, a fuel rail pressure sensor 228, a cam position sensor 230, a crankshaft position sensor 232, exhaust pressure sensors 234, an EGR temperature sensor 236, an EGR pressure sensor 237, an accelerator pedal position sensor 238 and a coolant temperature sensor 240.The control unit 210 is communicatively coupled to each sensor in the sensor system 216 to receive input signals from the various sensors, which are configured to generate signals in relation to various physical parameters of the drive system 100. Using the various acquired values, the control unit 210 can conventionally determine a number of parameters such as residual gas content in the intake manifold 154, EGR mass flow rate, PCV mass flow rate, and boost pressure level of the charging system 160, as indicated, for example, by the compression rate of the compressor 162.

[0033] In general, the controller 210 can generate output signals for transmission to various controlled devices, such as actuators, that control the operation of a thermal management system 260 and the drive system 100, including but not limited to the fuel injectors 136, the battery system 214, the motors 114 and 116, a throttle body 242, the EGR valve 186, a flow control valve 244, a pump 246, and a shut-off actuator 248. Note: Dashed lines can be used to indicate communication between the controller 100 and the various sensors and devices, but are generally omitted for clarity.

[0034] The controller 210 can consist of any number of electronic control modules and is configured to receive information from various sources, including the sensor system 216, process this information, and provide control signals / commands based thereon to achieve results such as the operation of the thermal management system 260, the drive system 100, and related systems, including the power electronics system 147. In the illustrated embodiment, the controller 210 comprises a processor 250 and a memory unit 252 and is coupled to a storage device 254. The processor 250 performs the computing and control functions of the controller 210 and can be any type of processor or multiple processors, individual integrated circuits, such as, for example,a microprocessor, or a suitable number of integrated circuit devices and / or printed circuit boards that work together to perform the functions of a processing unit. During operation, the processor 250 executes one or more programs and can use data, any of which may be contained in the storage device 254, and as such, the processor 250 controls the general operation of the controller 210 in the execution of the processes described herein, such as the one below in conjunction with . Fig. 4 processes described.

[0035] The memory unit 252 can be any type of suitable memory. For example, the memory unit 252 can include volatile and non-volatile storage in read-only memory (ROM), random access memory (RAM), and keep-alive memory (KAM). KAM can include persistent or non-volatile memory that can be used to store various operating variables while the processor 250 is powered off. The memory unit 252 can be implemented using any of the known memory devices such as PROMs (programmable read-only memory), EPROMs (erasable PROMs), EEPROMs (electrically erasable PROMs), flash memory, or other electrical, magnetic, optical, or combined memory devices capable of storing data, some of which may be executable instructions used by the controller 210.In certain embodiments, the memory unit 252 can be located on the same computer chip as the processor 250 and / or be co-located on the same computer chip. In the embodiment shown, the memory unit 252 can store the aforementioned programs together with one or more stored data values, e.g., for short-term data access.

[0036] The storage device 254 stores data, e.g., for long-term data access for use in the automatic control of the drive system 100 and the associated systems. The storage device 254 can be any suitable type of storage device, including direct-access storage devices such as hard disk drives, flash systems, floppy disk drives, and optical disk drives. In an exemplary embodiment, the storage device 254 comprises a source from which the storage unit 252 receives the programs that execute one or more embodiments of one or more processes of the present disclosure, such as those described below in connection with Fig. The four described steps of the process (and all its subprocesses) are described below. In another exemplary embodiment, the programs can be stored directly in the memory unit 252 and / or accessed from it in another way. The programs represent executable instructions used by the electronic control unit 210 in processing information and controlling the drive system 100 and its systems, including the power electronics system 147 and an integrated thermal management system 260, as described in more detail below. The instructions can contain one or more separate programs, each containing an ordered list of executable instructions for implementing logical functions. When executed by the processor 250, the instructions support the reception and processing of signals, e.g.from the various sensors, as well as the execution of logic, calculations, methods, and / or algorithms for the automatic control of the components and systems of the drive system 100. The processor 250 can generate control signals for the thermal management system 260 and for the automatic control of various components and systems of the drive system 100 based on logic, calculations, methods, and / or algorithms. The data storage device 254 can be part of the controller 210, separate from the control unit 210, part of one or more control units, or part of several systems. The storage unit 252 and the storage device 254 work together with the processor 250 to access and use the programs and data. While the components of the drive system 100 are presented as part of the same system, it is anticipated that these features may encompass multiple systems in certain embodiments.Furthermore, the drive system 100 can consist wholly or partially of various other vehicle devices and systems and / or be coupled to them in various embodiments.

[0037] The control unit 210 manages the operation of the thermal management system 260, including the drive system 100, the engine 110, the power electronics system 147, and the motors 114 and 116, to achieve the desired operating performance, including torque, speed, and emissions management. In general, the control unit 210 uses the available inputs, including the inputs of the sensor system 216 and the actuators identified therein, to supply the control unit 210 with parameter data to effectively control various functions. For example, based on the input data, the control unit 210 precisely calculates and controls the supply of the appropriate air-fuel mixture and exhaust gas recirculation through the operation of the fuel injectors 136, the throttle valve 242, the EGR valve 186, and the charging system 160, and can, if necessary, control other parameters such as the spark plug timing.The controller 210 also controls the power electronics system 147 and the motors 114 and 116 to deliver the appropriate torque. Instead of the controller 210, a different type of processor can be used to provide the electronic logic, e.g., an embedded controller, an on-board computer, or any processing module that can be used in the application.

[0038] In general, the power electronics system 147 comprises a traction power inverter module (TPIM) 270 and a reverse power inverter module (RPIM) 272. The two motors 114 and 116 are supplied with electrical energy by the TPIM 270 and the RPIM 272, respectively. In some embodiments, a different number of inverters may be used. It should be noted that in some embodiments, the TPIM 270 and / or the RPIM 272 may be assembled with the gearbox 112. The TPIM 270 and the RPIM 272 may each generally contain a power board, an intermediate circuit capacitor, EMC filters, control and gate drive boards, sensors, and a busbar, none of which are shown. Specific control algorithms for the motors 114 and 116 can be programmed into the control boards. During operation, the power electronics system 147 generates heat.Since the motors 114, 116 are integrated into the gearbox 112 in the current design, the heat is generated under most typical operating conditions of the drive system 100.

[0039] The thermal management system 260 is designed for thermal management, including controlling the dissipation of heat generated by the power electronics system 147. The thermal management system 260 operates a liquid circuit 280, including the pump 246, the flow control valve 244, and a heat exchanger in the form of a radiator 282. The pump 246 can be a variable-speed liquid pump driven by an electric motor. The flow control valve 244 can be an electromagnetically actuated variable-orifice valve. The radiator 282 can be a liquid-to-air heat exchanger to transfer heat from the liquid in the liquid circuit 280 to the ambient air. In some embodiments, the radiator 282 can be a low-temperature radiator operating below the boiling point of a liquid in the liquid circuit 280.The liquid circuit 280 is connected via an air separator 284 to an expansion tank 286 to remove air and allow expansion.

[0040] A loop 286 of the fluid circuit 280 generally comprises the pump 246, the cooler 282, the RPIM 272, and the TPIM 270. Accordingly, when the pump 246 is operating, fluid flows through the RPIM 272 and the TPIM 270 to collect heat and release it through the radiator 282. Both the TPIM 270 and the RPIM 272 have fluid passages through which the fluid circulates in the loop 286 to collect heat. The air movement above the radiator 282 can be controlled by louvers 288, which can be variably opened and closed by actuating the actuator 248 in response to the control 210. The temperature sensor 240 provides an input for use in controlling the speed of the pump 246, the position of the flow control valve 244 and the position of the fins 288.

[0041] Another loop 290 of the fluid circuit 280 is arranged parallel to loop 286 and generally comprises the pump 246, the heating element 282, an intercooler designated as a heat exchanger 166, and the flow control valve 244. Accordingly, flow occurs through loop 290 when both the pump 246 is operating and the flow control valve 244 is open. By operating the pump 246, the fluid circuit 280, and in particular loop 286, can be used to cool the power electronics system 147 when the flow control valve 244 is either open or closed. The fluid circuit 280, and in particular loop 290, can also be used to cool the air flowing through the intake duct system 156 when the temperature of the intake air is higher than the temperature of the fluid in the fluid circuit 280 and when the pump 246 is operating and the flow control valve 244 is open.The fluid circuit 280 can also be used to heat the air flowing through the intake duct system 156, in particular by a combination of loops 286 and 290, by collecting heat from the power electronics 147 and circulating the heat through the heat exchanger 166. To maximize heat storage, the fins 288 can be closed. To maximize heat dissipation to the charge air cooler, the flow control valve 244 is modulated open and can be fully opened. When the pump 246 is operating, the fluid circulating through the power electronics system 147 collects heat. The fluid then flows through the cooler 282, where the heat is retained by blocking the airflow over the cooler 282 through the closing of the fins 288. With the flow control valve 244 open, the heat is then released through the heat exchanger 166 for transfer to the intake air.

[0042] Selectively collecting heat from the power electronics system 147 to warm the intake air is advantageous for preventing condensation in the intake duct system 156 and the intake manifold. Accordingly, the current design generally determines, through the operation of the control unit 210, when there is a risk of condensation and operates the fluid system 280 to prevent condensation. With reference to Fig. 3 The thermal management system 260 is generally implemented by the operation of the controller 210 and can generally be set up to include a water content limit calculation module 302, a water content estimation module 304, a mode determination module 306, a heating control module 308, a cooling control module 310 and a data storage module 312.

[0043] With further reference to Fig. 4, together with the further reference to Fig.1-3, a process 400, as it can be carried out by the thermal management system 260, is depicted in the form of a flowchart. Process 400 begins 402, for example, when the operation of the drive system 100 begins. The sensor inputs, including those of sensor system 216, are read by 404, along with the inputs from other modules of the control unit 210. In particular, a signal 314, e.g., from the manifold pressure and temperature sensor 222, provides the water content calculation module 302 with an input about the temperature of the air in the intake manifold 154. A signal 316, e.g., from the manifold pressure and temperature sensor 222, provides an input about the pressure in the intake manifold 154 to the water content limit calculation module 302. A signal 318, e.g., from the intake port pressure sensor 218, provides an input about the pressure in the intake port system 156 upstream of the throttle body 242 to the water content limit calculation module 302. Additionally, a signal 320, e.g.,A signal 322, e.g., from a conventional module of the controller 210, provides a PCV mass flow rate estimate to the water content estimation module 304. A signal 324, e.g., from the air mass flow and temperature sensor 220, provides a fresh air mass flow rate to the water content estimation module 304. A signal 326, e.g., from a conventional module of the controller 210, provides an EGR mass flow rate estimate to the water content estimation module 304. A signal 328, e.g., from a conventional module of the controller 210, provides a residual gas fraction estimate to the water content estimation module 304.

[0044] Process 400 continues to calculate the water content limit in the intake manifold 154, for example, using the water content limit calculation module 302, with inputs 314, 316, and 318 used together with programs and data from the data memory 312. The water content limit is the maximum amount of water that the intake air can contain without condensation occurring at the operating temperature and operating pressure (saturation), and can be calculated using a conventional approach. The calculated water content limit is transmitted to the operating mode determination module 306 via a signal 330. Procedure 400 continues to estimate the water content in the intake air at the intake manifold 154, e.g., by the water content determination module 304, using inputs 320, 322, 324, 326, and 328 together with programs and data from the data memory 312. The water content estimate can be calculated using a conventional approach.The estimated water content 332 is transmitted via a signal to the mode determination module 306.

[0045] Method 400 determines, for example at the mode determination module 306, whether the fluid circuit 280 should be operated in a heating mode or a cooling mode by comparing the water content limit 330 with the estimated water content 332. If the estimated water content 332 is below the water content limit 330, determination 410 is negative, and process 400 initiates, for example by means of the cooling control module 310, the cooling operation 412 of the thermal management system 260 in a cooling mode. In several embodiments, the cooling operation can be delayed until the operation of the feeding system 160 is initiated. When cooling operation continues, process 400 opens the flap 288, e.g. by actuating the actuator 248 in response to a signal 336 from the cooling control module 310. Process 400 continues to modulate the flow control valve 244, e.g. by a signal 338 from the cooling control module 310.The flow control valve 244 can be partially or fully opened, depending on the required cooling volume, which is determined relative to a signal 340 of the boost level, as indicated, for example, by the compression rate of the compressor 162. A higher compression rate results in more cooling being delivered by opening the flow control valve 244 further.

[0046] Process 400 proceeds to command a pump speed 418 of pump 246, for example, by a signal 342 from the cooling control module 310. The pump speed can be determined using data from the data memory 312, which may be contained, for example, in a lookup table, to select a pump speed for the compression rate / gain level signal 340. An estimate 420 is made, for example, by the cooling control module 310, for the target temperature to be achieved by cooling through the liquid circuit 280. The estimate can be informed by a signal 344 from another conventional module of the controller 210, which determines the cooling commanded by the heat exchanger 166. Process 400 proceeds to determine 422, for example, by the cooling control module 310, whether the target temperature has been reached by comparing the target temperature with the signal 314, for example.from the manifold pressure and temperature sensor 222, which provides data on the temperature of the air in the intake manifold 154. If the determination 422 is negative and the target temperature has not been reached, the process 400 returns to controlling a pump speed 418 to reach the target temperature. In several embodiments, the process 400 can return to modulating the flow control valve 416 before commanding a pump speed 418. If the determination 422 is positive and the target temperature has been reached, the process 400 returns to reading the inputs 404 and continues.

[0047] Returning to step 410, as with mode determination module 306, the determination of whether the fluid circuit 280 should operate in a heating mode or a cooling mode is made by comparing the water content limit 330 with the estimated water content 332. If the estimated water content 332 is greater than or equal to the water content limit 330, determination 410 is positive, and process 400 initiates the heating operation 424 of the thermal management system 260 in a heating mode, e.g., by the heating control module 308. In a heating operation, process 400 closes the damper 288, e.g., by actuating the actuator 248 in response to a signal 346 initiated by the heating control module 308. The process 400 continues to open the flow control valve 244, e.g. by a signal 348 from the heating control module 308.The flow control valve 244 can be fully opened to heat the intake air as quickly as possible to avoid condensation.

[0048] Process 400 proceeds to control a pump speed 418 of pump 246, for example, by a signal 350 from the heating control module 308. The pump speed can be determined using data from the data storage 312, such as that contained in a lookup table, to select a pump speed for the ambient temperature, as communicated by signal 350 from the air mass flow and temperature sensor 220 of the ambient air temperature. An estimate 420 is made, for example, by the heating control module 308, for the target temperature to be reached by heating through the liquid circuit 280. The estimated value can be communicated by signal 350. Process 400 proceeds to determine 422, for example, by the heating control module 308, whether the target temperature has been reached by comparing the target temperature with signal 314, e.g.,from the manifold pressure and temperature sensor 222, which provides data on the temperature of the air in the intake manifold 154. If the result 422 is negative and the target temperature has not been reached, process 400 returns to controlling a pump speed 418 to reach the target temperature. If the result 422 is positive and the target temperature has been reached, process 400 returns to reading the inputs 404 and continues. When the drive system 100 is switched off, process 400 is terminated.

[0049] The aforementioned embodiments prevent condensation in the intake system. Heat from the power electronics of electric motors is selectively transferred to a heat exchanger (charge air cooler) to provide heat for condensation prevention based on a comparison between the limit value of the intake air water content and an estimated intake air water content. This assessment considers the contributions of ambient air, PCV gases, EGR gases, and residual gas fraction when determining the intake air water content at the intake manifold.

[0050] Although at least one exemplary embodiment has been presented in the foregoing detailed description, it should be understood that a multitude of variants exist. It should also be appreciated that the exemplary embodiment or embodiments are merely examples and are not intended to limit the scope, applicability, or configuration of the disclosure in any way. Rather, the foregoing detailed description will provide those familiar with the field with a convenient roadmap for implementing the exemplary embodiment or embodiments. It should be understood that various modifications in the function and arrangement of the elements can be made without deviating from the scope of the disclosure as defined in the appended claims and their legal equivalents.

Claims

[1] A thermal management system, comprising: a drive system (100) comprising an internal combustion engine (110) and an electric machine (114, 116); a power electronics system (147) from which the electrical power is supplied to the electrical machine (114, 116); a liquid circuit (280) designed to cool the power electronics system (147); an intake air heat exchanger (166) through which the intake air of the internal combustion engine (110) is circulated; and a controller (210) configured to operate the fluid circuit (280) to collect heat from the power electronics system (147) and selectively transfer the heat to the intake air heat exchanger (166), wherein the controller (210) is configured to calculate a water content limit of the intake air and estimate a water content of the intake air, wherein the controller (210) is configured to compare the estimated water content with the calculated water content limit to determine whether the intake air should be heated or cooled, wherein the controller (210) is configured to estimate a target temperature of the intake air and determine whether the target temperature has been reached after transferring the heat to the intake air heat exchanger (166). [2] The system according to claim 1, comprising flaps (288) arranged to control the airflow over the cooler (282), wherein the control (210) is configured to actuate the flaps (288). [3] The system of claim 1, comprising: a pump (246) in the fluid circuit (280); and a flow control valve (244) in the liquid circuit (280), wherein the control (210) is set up to operate the pump (246) and the flow control valve (244) in response to the water content in the intake air. [4] The system according to claim 1, wherein the control (210) is configured to estimate the water content in the intake air by evaluating an exhaust gas recirculation component of the intake air, a positive crankcase ventilation component of the intake air, a fresh air component of the intake air and a residual gas component of the intake air. [5] A method for controlling a thermal management system of a propulsion system comprising an internal combustion engine (110) and an electric machine (114, 116), the method comprising: Supplying power, through a power electronics system (147), to the electric machine (114, 116); Cooling of the power electronics system (147) by a liquid circuit (280); Circulation of the intake air of the internal combustion engine (110) through an intake air heat exchanger (166); and Operating, by means of a control (210), of the liquid circuit (280) to collect heat from the power electronics (147) and to selectively transfer the heat to the intake air heat exchanger (166); Calculating a water content limit value of the intake air by the control unit (210); Estimating the water content of the intake air by the control unit (210); Compare, by means of the control (210), the estimated water content with the calculated water content limit; and Determine, based on the comparison, whether the intake air should be heated or cooled; estimate a target temperature of the intake air and determine whether the target temperature has been reached after the heat has been transferred to the intake air heat exchanger (166).

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