Battery heating system for a vehicle

Abstract

Battery heating system (200) for a vehicle (112), comprising: a battery circuit (232) having a coolant pump (212), a battery coolant temperature sensor (204), an electronic component, a coolant proportional valve (208), and a battery (124); and a controller configured to in response to a battery coolant temperature being lower than a battery temperature, to turn on the coolant proportional valve (208) so that a coolant flow through the battery circuit (232) bypasses the battery (124), and in response to the battery coolant temperature exceeding the battery temperature, turn on the coolant proportional valve (208) so that the coolant flow through the battery circuit (232) does not bypass the battery (124); and a power electronics circuit (332) having an electronic coolant temperature sensor (210), a DC / DC converter (128), and an inverter system, wherein the controller is further configured to preheat a coolant in the power electronics circuit (332) by means of heat transfer between the coolant and the electronic component in response to an ambient temperature being below a threshold and the coolant temperature being lower than the battery temperature.

Description

TECHNICAL FIELD

[0001] This application generally relates to a thermal management system for a traction battery and power electronic components in an electrified vehicle. GENERAL STATE OF THE ART

[0002] Electrified vehicles include components and systems that require thermal management. For example, an engine's temperature is regulated by flowing coolant through the engine and using a radiator to lower the coolant temperature. Hybrid vehicles include additional components for which thermal management is beneficial. For example, the performance of traction batteries and power electronics modules may depend on maintaining temperatures below or above a certain threshold. Additional cooling systems may be installed in the vehicle to provide thermal management for traction batteries and power electronics modules.

[0003] Document DE 10 2017 118 832 A1 describes a thermal control system for a vehicle, the system comprising a coolant circuit, a power electronics device, and a radiator. The system also includes a battery bypass valve in the coolant circuit, which is configured to bypass the traction battery and the battery cooling device in a bypass position. The system further includes a controller programmed to operate the battery bypass valve in the bypass position in response to a demand for passenger compartment cooling being greater than a predetermined demand. Further relevant prior art relating to the background of the invention is provided by document US 2014 0 174 708 A1. SUMMARY

[0004] A battery thermal system for a vehicle includes a battery circuit with a coolant pump, a battery coolant temperature sensor, an electronic component, a coolant proportional valve, and a battery. The system further includes a controller that, in response to a coolant temperature being lower than a battery temperature, energizes the coolant proportional valve so that coolant flow through the battery circuit bypasses the battery, and, in response to the coolant temperature exceeding the battery temperature, energizes the coolant proportional valve so that coolant flow through the battery circuit does not bypass the battery. The system further includes a power electronics circuit with a coolant temperature sensor, a DC / DC converter, and an inverter system.The controller is further configured to preheat a coolant in the power electronics circuit via heat transfer between the coolant and the electronic component in response to an ambient temperature being below a threshold and the coolant temperature being lower than the battery temperature. The power electronics circuit may further include the coolant pump. The DC / DC converter or inverter system may be the electronic component. The coolant proportional valve may have a proportional transition and be capable of allowing variable coolant flow. The electronic component may be an inverter system or a DC / DC converter. The controller may be further configured to operate the battery at reduced power limits in response to the battery temperature being below a threshold. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram of a vehicle. Fig. Figure 2A is a schematic diagram of a battery heating circuit of a thermal management system. Fig. Figure 2B is a schematic diagram of a power electronics heating circuit of the thermal management system. Fig. 3 is a flowchart for controlling the thermal management system of the Fig. 2A and Fig. 2B. DETAILED DESCRIPTION

[0005] Embodiments of the present disclosure are described herein. It should be understood, however, that the disclosed embodiments are merely examples, and other embodiments may take various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or reduced to show the details of particular components. Accordingly, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. As one of ordinary skill in the art will understand, various features illustrated and described with reference to any of the figures may be combined with features shown in one or more other figures to produce embodiments not explicitly shown or described.The illustrated combinations of features provide representative embodiments for typical applications. However, various combinations and modifications of the features consistent with the teachings of this disclosure may be desirable for particular applications or implementations.

[0006] Electrified vehicles, including full hybrid electric vehicles (FHEVs), hybrid electric vehicles (HEVs), battery electric vehicles (BEVs), and plug-in hybrid-electric vehicles (PHEVs) with plug-in capability, have heating systems that can consume a significant portion of the vehicle's power. The fuel efficiency or electric range of the electrified vehicle may decrease due to the additional energy required by the heating system. This is because electric vehicles cannot generate as much heat as a conventional gasoline-powered vehicle.

[0007] The performance of electrified vehicles depends on the performance and temperature of a high-voltage traction battery. The traction battery or battery pack stores energy used by electrified vehicles. In colder temperatures, the HEV battery pack may perform less well due to the battery pack's higher internal resistance. The battery pack may need to be preheated to achieve better performance. Thermal management preheats a coolant using a power electronics coolant circuit with a DC / DC converter and an inverter system when the coolant temperature is lower than the battery temperature. The DC / DC converter may have bipolar transistors that heat a coolant circuit, and the heat is absorbed by the coolant.After the coolant temperature is higher than the battery temperature, the heated coolant can flow through the battery, enabling optimized battery performance.

[0008] The thermal management system in an HEV can be implemented to control a range of temperatures for the battery. The thermal management system can use air, liquid, or refrigerant for cooling or heating. The thermal management system can be either active or passive. A passive thermal management system uses the ambient air to cool or heat the battery pack. By using an active thermal management system, waste heat from the power electronics can be reused to heat the battery pack. A thermal management system can be controlled to utilize waste heat, improving the vehicle's fuel efficiency for optimal performance. Additionally, by heating the battery pack using hot fluid instead of an active heating element, vehicle weight and electrical energy are reduced because fewer components are used.

[0009] Fig. 1 shows an electrified vehicle, which may be an FHEV, HEV, BEV, or PHEV. A full hybrid electric vehicle may include one or more electric machines 114 mechanically coupled to a hybrid transmission 116. The electric machines 114 may operate as an electric motor or generator. Furthermore, the hybrid transmission 116 is mechanically coupled to an internal combustion engine 118. The hybrid transmission 116 is also mechanically coupled to a driveshaft 120, which is mechanically coupled to the wheels 122. The electric machines 114 may provide acceleration and deceleration capability when the internal combustion engine 118 is turned on or off. The electric machines 114 may also function as generators and may provide fuel efficiency benefits by recovering energy that would normally be lost as heat in a friction braking system.The electric machines 114 may also reduce vehicle emissions by enabling the internal combustion engine 118 to operate at more efficient speeds and by enabling the hybrid electric vehicle 112 to operate in electric mode, where the internal combustion engine 118 is turned off under certain conditions. In one example, the hybrid electric vehicle 112 may be a battery electric vehicle (BEV) that operates with or without the internal combustion engine 118.

[0010] A battery pack or traction battery 124 stores energy that can be used by the electric machines 114. The traction battery 124 can provide a high-voltage direct current (DC) output. The traction battery 124 can be electrically coupled to one or more power electronics modules 126. One or more contactors 142 can isolate the traction battery 124 from other components when open and connect the traction battery 124 to other components when closed. The power electronics module 126 is also electrically coupled to the electric machines 114 and provides the ability to transfer power bidirectionally between the traction battery 124 and the electric machines 114. For example, a traction battery 124 can provide a DC voltage, while the electric machines 114 can operate using three-phase alternating current (AC).The power electronics module 126 can convert the DC voltage into a three-phase AC current to operate the electric machines 114. In a regeneration mode, the power electronics module 126 can convert the three-phase AC current from the electric machines 114, which act as generators, into the DC voltage compatible with the traction battery 124.

[0011] The hybrid electric vehicle 112 may include a variable voltage converter (VVC) 152 electrically coupled between the traction battery 124 and the power electronics module 126. The VVC 152 may be a DC / DC boost converter configured to increase or boost the voltage provided by the traction battery 124. By increasing the voltage, current requirements may be lowered, resulting in a reduction in wiring size for the power electronics module 126 and the electric machines 114. Furthermore, the electric machines 114 may operate with better efficiency and lower losses.

[0012] In addition to providing propulsion power, the traction battery 124 may provide power to other vehicle electrical systems. The hybrid electric vehicle 112 may include a DC / DC converter module 128 that converts the high-voltage DC output of the traction battery 124 into a low-voltage DC supply compatible with low-voltage loads of the vehicle. An output of the DC / DC converter module 128 may be electrically coupled to an auxiliary battery 130 (e.g., a 12V battery) to charge the auxiliary battery 130. The low-voltage systems may be electrically coupled to the auxiliary battery 130. One or more electrical loads 146 may be coupled to the high-voltage bus. The electrical loads 146 may have an associated controller that optionally operates and controls the electrical loads 146.Examples of electrical loads 146 may be a fan, an electric heating element, and / or an air conditioning compressor.

[0013] The hybrid electric vehicle 112 may be configured to charge the traction battery 124 from an external power source 136. The external power source 136 may be a connection to an electrical outlet. The external power source 136 may be electrically coupled to a charger or electric vehicle supply equipment (EVSE) 138. The external power source 136 may be an electrical power distribution network, such as that provided by an electric utility company. The EVSE 138 may provide circuitry and controls to regulate and manage the transfer of energy between the power source 136 and the hybrid electric vehicle 112. The external power source 136 may provide electrical power to the EVSE 138 as direct current or alternating current. The EVSE 138 may include a charging connector 140 for plugging into a charging port 134 of the vehicle.The charging port 134 may be any type of port configured to transfer power from the EVSE 138 to the vehicle. The charging port 134 may be electrically coupled to a charger or an on-board power conversion module 132. The power conversion module 132 may condition the power supplied by the EVSE 138 to provide the proper voltage and current levels to the traction battery 124. The power conversion module 132 may interface with the EVSE 138 to coordinate the delivery of power to the vehicle. The charging plug 140 may have prongs that mate with corresponding recesses of the charging port 134. Alternatively, various components described as electrically coupled or connected may transfer power using wireless inductive coupling.

[0014] One or more wheel brakes 144 may be provided to decelerate the hybrid electric vehicle 112 and prevent movement of the hybrid electric vehicle 112. The wheel brakes 144 may be hydraulically actuated, electrically actuated, or a combination thereof. The wheel brakes 144 may be part of a braking system 150. The braking system 150 may include additional components to operate the wheel brakes 144. For simplicity, the figure shows a single connection between the braking system 150 and one of the wheel brakes 144. A connection between the braking system 150 and the additional wheel brakes 144 is implied. The braking system 150 may include a controller to monitor and coordinate the braking system 150. The braking system 150 may monitor the brake components and control the wheel brakes 144 to decelerate the vehicle.The braking system 150 can respond to driver commands and can also operate autonomously to implement functions such as stability control. The controller of the braking system 150 can implement a method for applying a requested braking force when requested by another controller or sub-function.

[0015] Electronic modules in the hybrid electric vehicle 112 may communicate over one or more vehicle networks. The vehicle network may include a plurality of communication channels. One channel of the vehicle network may be a serial bus, such as a Controller Area Network (CAN). One of the vehicle network channels may include an Ethernet network as defined by the Institute of Electrical and Electronics Engineers (IEEE) standards group 802. Additional vehicle network channels may include discrete connections between modules and may include power signals from the auxiliary battery 130. Different signals may be transmitted over different channels of the vehicle network. For example, video signals may be transmitted over a high-speed channel (e.g., Ethernet), while control signals may be transmitted over a CAN or discrete signals.The vehicle network can include any hardware and software components that support the transmission of signals and data between modules. The vehicle network is defined in . Fig. 1, but it may be implied that the vehicle network may connect to any electronic module present in the hybrid electric vehicle 112. A vehicle system controller (VSC) 148 may be present to coordinate the operation of the various components.

[0016] Fig. 2A shows a portion of the hybrid electric vehicle 112 ( Fig. 1), which includes a thermal management system 200 for controlling the temperature of the traction battery 124 and the power electronics components 234. In one example, the power electronics components 234 include the power electronics module 126 and the VVC 152 ( Fig. 1). The hybrid electric vehicle 112 may include a coolant circuit 250 configured to supply a thermal management coolant to the power electronics components 234 and the traction battery 124. The thermal management system 200 may include the components and subsystems described herein.

[0017] The thermal management system 200 may be configured to provide heating for the traction battery 124 of the hybrid electric vehicle 112. Although not described in the application, there is also a cooling mode to provide cooling for the traction battery 124. In the cooling mode, a two-way coolant valve (TBCV) 224 is open in response to a battery temperature exceeding a threshold, and coolant flows to a radiator 216. The TBCV 224 may be in a closed position during a heating and preheating mode. In one configuration, coolant flows through a battery circuit 232 ( Fig. 2A). In another operating mode, the coolant flows through the power electronics circuit 332 during the preheating mode ( Fig. 2B). The battery coolant temperature is determined, and temperature sensors communicate with a coolant proportional valve 208 to switch operation from either heating mode or preheating mode. The operating mode is illustrated using the thermal management system 200.

[0018] The thermal management system 200 may include a thermal controller that manages and controls the operation of the various components of the thermal management system 200. The thermal controller may be a single or multiple controller, where functionality is focused on a single controller or distributed across multiple controllers. The thermal management system 200 may include one or more temperature sensors. According to the invention, the temperature sensors are a battery coolant temperature sensor 204 and an electronic coolant temperature sensor 210. The battery coolant temperature sensor 204 and the electronic coolant temperature sensor 210 may provide a temperature reading for a battery coolant. The thermal controller may receive the temperature sensor inputs to direct the flow of battery coolant to a coolant passage of the traction battery 124.The coolant proportional valve 208 supplies coolant to the traction battery 124 when the coolant temperature exceeds a temperature threshold.

[0019] By controlling the flow of coolant, various vehicle components benefit from temperature control. For example, the traction battery 124 can perform at its peak within a specific temperature range. The optimal temperature range can affect battery performance and battery life. Operating within the temperature range can maintain battery life and performance. Additionally, the temperature of the power electronics module 126 and the VVC 152 may need to be kept below a threshold temperature to extend the life of these components. Furthermore, improved vehicle fuel efficiency can be achieved at certain battery temperatures.

[0020] The coolant circuit 250 is configured to direct the coolant through the power electronics components 234 and the traction battery 124. The power electronics components 234 and the traction battery 124 may be located in the same coolant circuit 250. Such a configuration reduces costs because an active heating element is not required and no additional components such as pumps, cooling lines, and valves are present. The coolant circuit 250 may include pipes, conduits, hoses, channels, and fittings through which the coolant can flow. The coolant circuit 250 may include a number of paths through which coolant can flow. The paths through which coolant can flow can be controlled by various valves to be described herein. Each of the paths may include any conduits and fittings necessary to enable coolant flow through the associated path.

[0021] The traction battery 124 may include a battery heat exchanger 202 configured to transfer heat to and from the traction battery 124. The battery heat exchanger 202 may transfer heat between the traction battery 124 and a coolant flowing through the battery heat exchanger 202. In one example, the battery heat exchanger 202 may transfer heat from the coolant to the traction battery 124 when the coolant temperature is higher than the traction battery temperature.

[0022] The thermal management system 200 may include a battery cooler 206. The battery cooler 206 may be part of the vehicle's air conditioning system and is used to cool the coolant flowing to the battery heat exchanger 202. One or more valves may be present in the refrigerant lines to direct refrigerant to the air conditioning system and / or battery cooler 206. The battery cooler 206 may be operated to reduce the temperature of the coolant entering the battery heat exchanger 202.

[0023] The power electronics components 234 may include the VVC 152 and may further include a VVC heat exchanger configured to transfer heat to and from the VVC 152. The VVC heat exchanger may transfer heat between the VVC 152 and a coolant flowing through the VVC heat exchanger. The VVC heat exchanger may transfer heat from the coolant to the VVC 152 when the coolant temperature is higher than a temperature of the VVC 152. The VVC heat exchanger may transfer heat from the VVC 152 to the coolant when the coolant temperature is lower than the VVC temperature.

[0024] The power electronics components 234 may similarly include an inverter system controller (ISC) 126 and may include an ISC heat exchanger 226 configured to transfer heat to and from the ISC 126. The ISC heat exchanger 226 may transfer heat between the ISC 126 and a coolant flowing through the ISC heat exchanger 226. The ISC heat exchanger 226 may transfer heat from the coolant to the ISC 126 when the coolant temperature is higher than the ISC temperature. The ISC heat exchanger 226 may transfer heat from the ISC 126 to the coolant when the coolant temperature is lower than the ISC temperature.

[0025] The thermal management system 200 may include a traction battery coolant pump (TBCP) 212 configured to flow coolant within the coolant circuit 250. The TBCP 212 may be controlled by adjusting a voltage or current input to cause rotation at a desired speed. In some configurations, the TBCP 212 may be configured to operate at variable speeds to vary the flow rate of coolant through the coolant circuit 250. The operation of the coolant circuit 250 may be such that coolant flowing through each circuit may traverse selected paths and return to the TBCP 212 for continued recirculation through the coolant circuit 250.

[0026] The thermal management system 200 may include a radiator 216 within the coolant circuit 250. The coolant circuit 250 may define a radiator path that directs coolant through the radiator 216. The TBCV 224 may be located in the radiator path and may be configured to direct the coolant to the radiator 216. As coolant flows through the radiator 216, heat is transferred from the coolant to the air flowing past the radiator 216. A fan 220 near the radiator 216 may be configured to increase the heat dissipated by the coolant. In one example, the fan 220 may be an electric fan. In another example, the fan 220 may be a belt-driven fan, where the fan 220 is connected to a crankshaft of the internal combustion engine 118 ( Fig. 1). An ambient temperature sensor 222 is located near the fan 220. The ambient temperature sensor 222 may be configured to be mechanically or electrically coupled to the thermal controller and receive instructions from the thermal controller. The radiator 216 may include a series of channels through which coolant flows from one side of the radiator 216 to the other. Metal may be formed between the channels in a ribbed pattern that increases a surface area for heat transfer. Coolant exiting the radiator 216 is typically at a lower temperature than coolant entering the radiator 216.

[0027] The coolant proportional valve 208 is configured to selectively direct coolant in the coolant circuit 250 to the battery circuit 232 or the power electronics circuit 332. In one example, the battery circuit 232 includes the traction battery 124, the battery cooler 206, and the power electronics components 234. The coolant proportional valve 208 may include a solenoid coupled to a valve mechanism such that a position of the coolant proportional valve 208 may be controlled by the thermal controller. For example, a coolant proportional valve signal may be output from the thermal controller to control the position of the coolant proportional valve 208. In one mode, the coolant proportional valve 208 may have a binary mode. In binary mode, the coolant proportional valve 208 is either open or closed. In another mode, the coolant proportional valve 208 may have a variable mode.In variable mode, the coolant proportional valve 208 can adjust the proportion of coolant flow in both the battery circuit 232 and the power electronics circuit 332. For example, the coolant proportional valve 208 can also be configured to allocate large amounts of coolant to the battery circuit 232 and small amounts of coolant to the power electronics circuit 332. In another example, the coolant proportional valve 208 can flow 50% of the coolant to the battery circuit 232 and 50% of the coolant to the power electronics circuit 332. In yet another example, the variable mode can be used when the coolant proportional valve 208 is controlled to flow a small amount of coolant to the battery circuit 232 to heat the traction battery 124 to increase the battery temperature more quickly.

[0028] The thermal management system 200 may include temperature sensors located at various locations to measure battery temperatures and / or coolant temperatures. An electronic coolant temperature sensor 210 may be configured to measure a temperature of the coolant in the coolant circuit 250. In one example, the electronic coolant temperature sensor 210 may be located near the coolant proportional valve 208 and the TBCP 212. In another example, the electronic coolant temperature sensor 210 may be located downstream of the coolant proportional valve 208 and upstream of the TBCP 212.

[0029] The battery coolant temperature sensor 204 may be configured to measure a temperature of the coolant before the coolant flows upstream of the traction battery 124. In one example, the battery coolant temperature sensor 204 may be located upstream of the battery heat exchanger 202 and downstream of the battery cooler 206 to measure the temperature of the coolant after the coolant has passed through the battery cooler 206.

[0030] A battery temperature sensor 228 may be configured to measure the temperature associated with the traction battery 124. For example, the battery temperature sensor 228 may be configured to measure a temperature at a location within the traction battery 124 that is indicative of a temperature of cells comprising the traction battery 124. The temperature output of the battery temperature sensor 228 may be compared to a predetermined temperature, after which further action may be taken. If the coolant temperature is higher than the predetermined temperature, the coolant proportional valve allows coolant to flow to the traction battery 124. If the coolant temperature is below the predetermined threshold, the coolant proportional valve switches to a coolant bypass mode. The temperature sensors 204, 210, and 228 may be electrically coupled to one or more controllers.For example, each of the temperature sensors can be electrically coupled to the thermal control.

[0031] When the coolant proportional valve 208 is configured to flow liquid in the battery circuit 232, it may direct coolant to the battery circuit 232. The battery circuit 232 may define a battery path that directs coolant through the traction battery heat exchanger and the battery cooler 206, in addition to the VVC heat exchanger and the ISC heat exchanger 226. When the coolant proportional valve 208 is configured to flow liquid in the power electronics circuit 332, it may direct coolant to the power electronics circuit 332. The power electronics circuit 332 may define a power electronics path that directs coolant through the VVC heat exchanger and the ISC heat exchanger 226, bypassing the battery cooler 206 and the traction battery 124.In both the battery circuit position and the power electronics circuit position, the power electronics circuit 332 may route coolant through the VVC heat exchanger and the ISC heat exchanger 226.

[0032] In a further operating mode of the thermal management system 200, as in Fig. 2B, coolant flows through the coolant circuit 250 during a preheating mode. This mode may be useful during a vehicle cold start. During a vehicle cold start, the traction battery 124 may be operating at a temperature below an optimal operating temperature. When the traction battery 124 is below an optimal operating temperature range, the traction battery 124 may be heated using heat generated by the power electronics components 234. In this example, the power electronics components 234 of the hybrid electric vehicle 112 ( Fig. 1) in the power electronics circuit 332, which bypasses the traction battery 124 and the battery cooler 206. The coolant proportional valve 208 directs the coolant to a cooler bypass line 230 and to the power electronics components 234. The power electronics circuit 332 directs coolant through the VVC heat exchanger and the ISC heat exchanger 226 to heat the coolant and preheat the traction battery 124. The coolant circulates through the power electronics circuit 332 until the coolant temperature is higher than the battery temperature. The TBCV 224 is configured to direct coolant to a radiator bypass line 231 to bypass the radiator 216 in the power electronics circuit 332.

[0033] The electronic coolant temperature sensor 210 may be configured to measure a temperature of the coolant in the power electronics circuit 332. The electronic coolant temperature sensor 210 is located, for example, near the coolant proportional valve 208 and the TBCP 212. By placing the electronic coolant temperature sensor 210 upstream of the coolant proportional valve 208, the temperature of the coolant may be determined. Once it is determined that the coolant temperature is above a predetermined threshold, the coolant proportional valve 208 may be switched to the battery circuit 232. In one example, the predetermined threshold is a predetermined temperature range. The predetermined temperature may be a temperature that is lower than a normal operating temperature of the power electronics components 234 in the power electronics circuit 332.In another example, the predetermined threshold is a predetermined time.

[0034] Fig.3 shows a flowchart for a possible sequence of operations that may be implemented in a controller (e.g., vehicle system controller 148) to control the operation of the thermal management system. The operations may be implemented and executed in the thermal controller. At operation 400, the HEV is turned on. A battery heating request is subsequently sent at 402. The traction battery requests heating when the battery temperature is below a calibrated battery temperature at which the traction battery would operate at reduced power limits. If the traction battery does not need heating, the instruction is sent back to step 400 to continually check whether the traction battery needs heating. If the traction battery needs heating, the flow continues to step 404. A battery coolant sensor may measure the battery coolant temperature in battery circuit 232.A battery temperature sensor may measure a temperature of the traction battery 124. The thermal controller may receive signals representing both the battery coolant temperature and the battery temperature. At step 404, the thermal controller may check whether the battery coolant temperature is higher than the battery temperature.

[0035] At step 404, the thermal controller may check for a cold start condition of the vehicle. If the coolant temperature is lower than the battery temperature, preheating of the power electronics circuit 332 occurs at step 406. The TBCP 212 is enabled at step 408, allowing coolant to flow through a coolant passage. At step 410, the TBCV 224 may be positioned to prevent coolant flow to the radiator 216. In response to the coolant temperature being lower than a battery temperature, the coolant proportional valve 208 is switched to bypass the battery circuit 232, allowing coolant to flow in the power electronics circuit 332, bypassing the traction battery 124 at step 412.

[0036] Conditions for exiting the power electronics circuit 332 are checked, and if met, heating of the battery circuit occurs at step 416. For example, one condition may be that the coolant temperature exceeds the battery temperature. The TBCP 212 is turned on at step 418, allowing coolant to flow through the coolant channel. The TBCV 224 is then positioned to prevent coolant flow to the radiator 216 at operation 420. The coolant proportional valve 208 may be controlled to position the valve in a battery circuit position 223, allowing coolant to flow through the coolant channel of the battery circuit 232 at step 422. The sequence of operations may be repeated periodically to maintain control of the valves as operating conditions change.

[0037] Although exemplary embodiments are described above, these embodiments are not intended to describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure. As described above, the features of various embodiments may be combined to form further embodiments of the invention that may not be explicitly described or illustrated.While various embodiments may be described as advantageous or preferred over other prior art embodiments or implementations with respect to one or more desired characteristics, one of ordinary skill in the art will recognize that one or more features or characteristics may be compromised to achieve the desired overall system attributes, depending on the particular application and implementation. These attributes include, but are not limited to, cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, maintainability, weight, manufacturability, ease of assembly, etc. Therefore, embodiments described as less desirable than other prior art embodiments or implementations with respect to one or more characteristics are not outside the scope of the disclosure and may be desirable for certain applications.

Claims

[1] A battery heating system (200) for a vehicle (112), comprising: a battery circuit (232) having a coolant pump (212), a battery coolant temperature sensor (204), an electronic component, a coolant proportional valve (208), and a battery (124); and a controller configured to in response to a battery coolant temperature being lower than a battery temperature, to turn on the coolant proportional valve (208) so that a coolant flow through the battery circuit (232) bypasses the battery (124), and in response to the battery coolant temperature exceeding the battery temperature, turn on the coolant proportional valve (208) so that the coolant flow through the battery circuit (232) does not bypass the battery (124); and a power electronics circuit (332) having an electronic coolant temperature sensor (210), a DC / DC converter (128), and an inverter system, wherein the controller is further configured to preheat a coolant in the power electronics circuit (332) by means of heat transfer between the coolant and the electronic component in response to an ambient temperature being below a threshold and the coolant temperature being lower than the battery temperature. [2] The battery thermal system (200) of claim 1, wherein the power electronics circuit (332) further includes the coolant pump (212). [3] The battery thermal system (200) of claim 1, wherein the DC / DC converter (128) or the inverter system is the electronic component. [4] The battery thermal system (200) of claim 1, wherein the coolant proportional valve (208) has a proportional transition and is capable of allowing a variable coolant flow. [5] The battery thermal system (200) of claim 1, wherein the controller is further configured to operate the battery (124) at reduced power limits in response to the battery temperature being below a threshold.

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