A thermal management system for electric vehicle applications

Abstract

A thermal management system for an electric vehicle, comprising: a main circuit having a main pump configured to circulate coolant through a high-voltage heater, at least one cooler, and at least one electric drive unit; a supplementary circuit having a supplementary pump configured to circulate coolant through at least one supplementary electric drive unit and a supplementary cooler; a battery circuit having a battery circuit pump configured to circulate coolant through a high-voltage energy storage system; at least one supplementary circuit valve operable to selectively fluidly connect the supplementary circuit to the main circuit; at least one battery circuit valve operable to selectively fluidly connect the battery circuit to the main circuit; and a controller configured to regulate the pumps and valves so as to route coolant between the circuits based on thermal demands.

Description

[0001] A THERMAL MANAGEMENT SYSTEM FOR ELECTRIC VEHICLE APPLICATIONS

[0002] TECHNICAL FIELD

[0003] The present invention generally relates to thermal management systems for electric vehicles.

[0004] BACKGROUND

[0005] Electric vehicles and similar advanced systems rely on a variety of mechanical and electronic components that each generate, absorb, or transfer heat. Historically, developers attempted to cool these components with single-loop or similarly rigid thermal management systems that often forced coolant through every cooler or heat exchanger, regardless of immediate demand. Although effective under certain conditions, such configurations proved to be inflexible and prone to a range of deficiencies. One common shortcoming was the tendency to create localized overheating, because multiple heat-generating components, such as high-voltage batteries, electric drive units, and power electronics, were forced to share the same cooling capacity without any intelligent routing of coolant. In cases where the load became particularly high, such as during heavy towing or when driving up steep gradients in hot ambient temperatures, insufficient or misdirected coolant flow could cause temperature spikes that risked damaging critical components.

[0006] Another persistent challenge in prior art systems was inadequate energy efficiency. By keeping the entire system at full cooling capacity even in moderate or cold conditions, older approaches wasted energy and often overcooled components, leading to a secondary problem of excessive heating demands in winter. Furthermore, because components like high-voltage battery modules are extremely sensitive to temperature, repeated exposures to suboptimal thermal conditions could shorten their service life, requiring costly and frequent replacements. This issue extended to other subsystems as well, as prolonged overheating or thermal cycling often caused premature wear on power electronics, drive units, and even cabling.

[0007] Prior solutions also struggled with overall performance optimization. Whenever a critical component overheated, a conservative control strategy might throttle the entire powertrain, curtailing vehicle performance in order to protect against damage. This approach, while necessary, resulted in inconsistent or degraded performance and undermined the user experience. In addition, the lack of precise thermal regulation often forced engineers to design oversized cooling assemblies, which added mass, took up valuable vehicle space, and introduced more aerodynamic drag or mechanical complexity. In many cases, these heavier orlarger cooling systems increased both energy consumption and noise levels, defeating efficiency goals and diminishing ride quality.

[0008] In certain applications, noise reduction was a key priority that older cooling designs often could not meet. Large fans and pumps running at high speeds created sound output that was particularly intrusive, especially in contexts where quiet operation was a critical factor. Moreover, traditional solutions were limited in their scalability. A cooling loop sized for a compact sedan might be inadequate for a commercial truck, while a system designed for an industrial machine might be too bulky or energy-intensive for a smaller electric vehicle. This lack of flexibility and configurability placed significant constraints on designers, forcing them to either overbuild or compromise on performance. Concerns about environmental impact further underscored the limitations of prior art methods. Inefficient cooling required more power from batteries or from the grid, indirectly increasing carbon emissions. The need for additional or more powerful refrigerants also contributed to higher ecological footprints. Lastly, many conventional systems were not robust enough for harsh environments, where extreme temperatures or dusty conditions could easily overwhelm standard radiators and fans.

[0009] Taken together, these shortcomings in older or less adaptive approaches to thermal management illustrate the necessity for a more sophisticated, multi-circuit design that can conserve energy, control noise, adapt to varied thermal loads, and extend component life. The present invention answers this need by offering a flexible architecture of interlinked coolant circuits, each capable of targeted heating or cooling and each able to merge or isolate in response to real-time demands. This multi-circuit solution enables greater reliability and efficiency than was previously achievable with single-loop or rigidly configured systems.

[0010] SUMMARY

[0011] The invention provides a multi-circuit thermal management system that addresses prior art shortcomings by taking a nuanced approach to heating and cooling in electric vehicles and similarly demanding applications. Rather than forcing coolant to follow a single path, the new architecture uses separate but interconnectable circuits, referred to here as the main circuit, supplementary circuit, and battery circuit, to handle different thermal loads and ambient conditions. The main circuit distributes heat or cooling among a variety of components such as the vehicle’s high-voltage heater, electric drive unit(s), power electronics, and passenger cabin HVAC. A supplementary circuit manages at least one additional electric drive unit, allowing it to reject heat independently via its own cooler or draw on the main circuit’s cooling capacity under heavy loads. Meanwhile, the battery circuit is dedicated to preserving the high-voltageenergy storage system within safe temperature boundaries, preventing overheating during fast charging or discharging, and facilitating rapid warming in cold weather.

[0012] In aerothermal terms, this multi-circuit solution is designed to make optimal use of ambient air and fluid dynamics, employing heat exchange surfaces and advanced thermal energy conversion where needed. By integrating these aerothermal strategies, the system can dissipate excess heat efficiently through a combination of passive and active cooling approaches, thereby preventing localized overheating and ensuring that each major subsystem remains within optimal temperature limits. The use of selective coolant routing and bypass lines further enhances system energy efficiency, as coolant is not forced to traverse all coolers under every operating condition.

[0013] Valves connecting the three circuits ensure that coolant is directed precisely to where it can be most effectively used. In winter, for instance, the high-voltage heater may quickly warm the battery circuit while bypassing external radiators to retain heat. Under high-load or hot summer conditions, multiple coolers, potentially enhanced by aerodynamic airflow, are engaged in parallel or series, enabling the system to reject heat to the environment more intensively. Aerothermal integration in this context refers to the synergy between coolant flow and ambient air management, possibly employing sophisticated ducting, thermal radiation methods, or novel heat-exchanger shapes to reduce drag, weight, and noise. Consequently, even in harsh environments with extreme temperatures or dusty conditions, the system can autonomously adjust its cooling capacity, ensuring reliable operation and limiting the thermal stress on all vehicle components.

[0014] Overall, the multi-circuit and aerothermally optimized design not only addresses the fundamental issues of overheating and inefficiency but also extends component lifespans by mitigating thermal stress. Because coolant flow and heat rejection methods can be tailored to the vehicle’s size, drive configuration, and operational demands, manufacturers can scale this approach from compact electric sedans to heavy-duty commercial vehicles. By regulating pump speeds and using only the necessary cooling paths, the invention also curtails noise output and helps lower energy consumption. These improvements align with evolving environmental standards, reducing the reliance on harmful refrigerants and minimizing the carbon footprint of transportation. In essence, the invention offers an adaptive, balanced method for managing thermal loads in advanced vehicles, representing a decisive step beyond the inflexible and often inefficient single-loop solutions of the prior art.In one aspect of the invention, there is provided a thermal management system for an electric vehicle, comprising a main circuit having a main pump configured to circulate coolant through a high-voltage heater, at least one cooler, and at least one electric drive unit; a supplementary circuit having a supplementary pump configured to circulate coolant through at least one supplementary electric drive unit and a supplementary cooler; a battery circuit having a battery circuit pump configured to circulate coolant through a high-voltage energy storage system; at least one supplementary circuit valve operable to selectively fluidly connect the supplementary circuit to the main circuit; at least one battery circuit valve operable to selectively fluidly connect the battery circuit to the main circuit; and a controller configured to regulate pumps and valves so as to route coolant between the circuits based on thermal demands. This arrangement allows multiple distinct coolant loops to separately manage the thermal loads of various vehicle components. Therefore, it is possible to optimize heat exchange for each subsystem, leading to improved energy efficiency and extended component lifespan.

[0015] In a preferred embodiment, the thermal management system further comprises a battery circuit cooler disposed in the battery circuit, wherein the battery circuit cooler is selectively bypassable to retain heat in cold ambient conditions or enhance cooling in hot ambient conditions. This feature allows the battery circuit to bypass its cooler when external cooling is unnecessary, thereby conserving heat and reducing energy losses. Therefore, it is possible to maintain optimal battery temperatures in both cold and hot conditions without overtaxing the cooling system.

[0016] In another preferred embodiment, the system includes a battery circuit plate heat exchanger configured to exchange thermal energy between the battery circuit and the main circuit when the at least one battery circuit valve is open. Such a configuration provides an additional pathway for balancing thermal loads across different loops, so that battery heat can be dissipated via the main circuit or supplemented by heat from the main circuit if warming is needed. Therefore, it is possible to fine-tune battery temperature in real time.

[0017] In yet another preferred embodiment, the system further comprises a main heat pump in fluid communication with the main circuit, and a main plate heat exchanger arranged to transfer heat between the coolant and an external refrigerant loop, wherein the controller is configured to operate the main heat pump in heating or cooling mode depending on detected temperatures. This arrangement allows the thermal management system to utilize heat pump technology for both heating and cooling, thereby enhancing overall energy efficiency. Therefore, it is possible to reduce reliance on dedicated heating elements and improve thermal flexibility across various operating conditions.In still another preferred embodiment, a DC-DC converter is provided in fluid communication with the coolant in the main circuit, wherein the DC-DC converter is cooled or heated by the main circuit to maintain an optimal operating temperature. This feature allows the system to protect sensitive power electronics from thermal stress. Therefore, it is possible to prolong the lifespan of the DC-DC converter and ensure reliable performance under varying load conditions.

[0018] In a further preferred embodiment, the main circuit further comprises an HVAC heat exchanger for regulating passenger cabin temperature, the controller being configured to direct coolant through the HVAC heat exchanger in response to a cabin heating or cooling request. Such a configuration provides the additional benefit of integrating cabin climate control with the vehicle’s powertrain cooling loops. Therefore, it is possible to utilize recovered heat for passenger comfort, enhancing overall energy efficiency.

[0019] In another preferred embodiment, the supplementary circuit valve is actuated by the controller in response to a threshold temperature of the at least one supplementary electric drive unit, thereby enabling coolant exchange between the supplementary circuit and the main circuit for enhanced heat rejection or retention. This design allows the supplementary drive unit to access greater or lesser cooling capacity as needed. Therefore, it is possible to prevent overheating or underheating of the supplementary electric drive unit and maintain optimal performance levels.

[0020] In a further preferred embodiment, the battery circuit valve is actuated by the controller in response to a threshold temperature of the high-voltage energy storage system (HV ESS), thereby enabling heated or cooled fluid from the main circuit to flow into the battery circuit. Such an approach provides a targeted method for preventing thermal excursions in the battery. Therefore, it is possible to maintain a stable temperature range in the HV ESS, improving safety and extending battery life.

[0021] In another preferred embodiment, each of the main pump, the supplementary pump, and the battery circuit pump is a variable-speed pump, and the controller is configured to modulate pump speed based on real-time thermal demands to reduce energy consumption. This method allows the system to dynamically adjust coolant flow rates without running pumps at full capacity at all times. Therefore, it is possible to achieve more efficient use of electrical power while meeting cooling or heating requirements.

[0022] In yet a further preferred embodiment, at least one cooler in each circuit includes a bypass line, and the controller is configured to divert coolant around the cooler when external cooling is not required, thereby minimizing unnecessary heat rejection. Such a bypass capabilityprovides finer control over the thermal profile of each circuit. Therefore, it is possible to reduce parasitic losses, shorten warm-up times, and optimize energy usage under varying operational conditions.

[0023] Below is further specific information about some of the components of the system. The main circuit handles primary temperature regulation for the most heat-intensive powertrain components. It may connect a high-voltage heater, at least one cooler, and one or more electric drive units, directing coolant through a large front heat exchanger or radiator to dissipate unwanted heat. By concentrating major cooling loads within this circuit, the vehicle can consistently maintain safe operating temperatures for electronics such as a DC-DC converter, which can be placed in-line with the coolant flow. The main circuit may also feed an HVAC heat exchanger, enabling residual or waste heat from the powertrain to be repurposed for passenger cabin comfort.

[0024] A supplementary circuit is typically dedicated to an additional electric drive unit or another subsystem that does not always require the full capacity of the main circuit. Equipped with its own pump and cooler, this circuit can function autonomously when its thermal load is relatively low. In scenarios of increased demand, such as towing a heavy load or climbing steep inclines, the supplementary circuit’s temperature sensors may detect a threshold that triggers a valve to connect it with the main circuit. This interplay lets the supplementary circuit tap into the larger radiators or the main heat pump, thereby preventing overheating without forcing the entire system to operate at maximum capacity at all times.

[0025] The battery circuit focuses on the high-voltage energy storage system, a component whose performance and longevity depend heavily on maintaining an optimal temperature range. A battery circuit pump circulates coolant through or around the battery modules, often making use of a dedicated cooler that can be bypassed in cold weather to retain heat. In certain designs, a plate heat exchanger is present to transfer heat to or from the main circuit without intermixing fluids, offering greater flexibility to either warm the battery using the main circuit’s high-voltage heater or cool it more aggressively by accessing additional radiators. This isolated design ensures that battery thermal management needs do not compromise the rest of the powertrain.

[0026] Each circuit relies on valves and optional bypass lines to regulate fluid routing. These valves respond to signals from temperature sensors, opening or closing to either merge circuits, divert coolant, or exclude certain coolers. Such an arrangement keeps pumping energy under control, since liquid flows only where it is truly needed. Variable-speed pumps enhance this effect by scaling their operation to match real-time thermal loads, thereby reducing energyconsumption and noise. In colder conditions, bypassing coolers accelerates component warmup and prevents unnecessary heat rejection to the environment; in hotter conditions or under heavy load, coolers can be brought fully online to dissipate heat quickly and avoid performance throttling.

[0027] The system can also incorporate additional elements such as a main heat pump, a DC-DC converter cooling plate, or specialized HVAC interfaces for the passenger cabin. A reversible heat pump, for instance, can add heat to the main circuit on a cold morning or draw heat out of the system under summer extremes. By situating a DC-DC converter directly within the coolant flow, sensitive electronics are kept within safe operating temperatures, avoiding thermal degradation or shutdown. An HVAC heat exchanger can route hot coolant through the cabin’s ventilation system when passenger heating is desired or, alternatively, accept chilled coolant to support air conditioning.

[0028] When further enhanced by aerothermal integration, these circuits can exploit optimal airflow paths, specialized ducting, and advanced heat exchanger surfaces to improve the transfer of thermal energy to or from ambient air. For example, a large front radiator might be paired with precisely shaped vents and shutters that open or close based on the need for cooling, reducing aerodynamic drag when minimal airflow is required. The system’s reliance on adaptive pumps and valves means that it can effectively operate in a broad spectrum of conditions, from sub-freezing winter starts to high-load summer drives in mountainous regions. By intelligently managing thermal pathways, it not only prevents overheating of high-stress components but also conserves energy and lowers noise emissions when demands are mild.

[0029] This multi-circuit approach delivers a combination of flexibility, efficiency, and robustness that surpasses older single-loop designs. The isolated battery circuit preserves the integrity and health of the high-voltage energy storage system, the main circuit shoulders the brunt of general cooling and heating tasks, and the supplementary circuit tailors its usage to secondary drive units or auxiliary subsystems. Meanwhile, thoughtful placement of valves and bypasses ensures minimal wasted energy. Thanks to the option of integrating various heat exchangers, a heat pump, aerodynamic airflow enhancements, and precision-controlled pumps, this arrangement caters to an array of applications. It can be scaled from compact passenger cars to heavy-duty commercial vehicles, reliably handling extreme ambient temperatures, high-power driving conditions, and demanding operational schedules, all while minimizing environmental impact.

[0030] These and other features, aspects and advantages of the invention will become better understood with reference to the following drawings, descriptions and claims.BRIEF DESCRIPTION OF DRAWINGS

[0031] The invention will be described in detail with reference to example embodiments shown in the drawings, wherein:

[0032] FIG. 1 is a schematic diagram illustrating a thermal management system according to an embodiment of the present invention, showing the three main coolant circuits and their interconnections.

[0033] DETAILED DESCRIPTION

[0034] The following detailed description is of the best currently contemplated modes of carrying out the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention.

[0035] In an exemplary embodiment, an electric vehicle is equipped with a comprehensive thermal management system that employs three interlinked coolant circuits. These circuits, referred to herein as the main circuit, the rear drive circuit (functioning as a supplementary circuit), and the high voltage energy storage system (HV ESS) circuit (functioning as a battery circuit), are configured to provide or absorb heat from various components throughout the vehicle. By selectively opening or closing valves and potential bypass lines between these circuits, the vehicle’s controller can redirect coolant flow to optimize heating or cooling performance in real time, including bypassing certain coolers when air cooling is not required.

[0036] Referring first to FIG. 1, the main circuit 100 is arranged to manage several critical elements of the vehicle’s thermal demands. A pump 116 propels coolant through a number of components, including an HVAC heat exchanger 110 for passenger climate control, a high voltage heater (HVH) 111, two coolers 112 and 115 (often placed at the front or rear of the vehicle to exhaust heat to ambient air), left and right front electric drive units (EDUs) 113 and 114, a DC-DC converter 117, and a main plate heat exchanger (main PHX) 118 that interfaces with a main heat pump 119. If additional heat is required, particularly in cold weather, then the high-voltage heater 111 can energize and rapidly warm the circulating coolant. Conversely, if the system is in a cooling mode, the main heat pump 119 can help transfer thermal energy out of the coolant via the main PHX 118.

[0037] As the coolant travels through or around the coolers 112 and 115, these components can be bypassed when air cooling is not necessary. For example, in cold winter conditions, rather than dumping heat to the ambient environment, the system may maintain valuable thermal energy within the circuit by routing coolant around one or both coolers. Such bypasses aretypically achieved through dedicated valves or bypass lines that redirect coolant flow. In this manner, heat from the EDUs or other sources can be retained for use in the cabin heating system or for warming other components, enhancing overall efficiency.

[0038] Turning to the rear drive circuit 120 (i.e. the supplementary circuit), a dedicated pump 121 propels coolant through the rear electric drive unit (rear EDU) 122 and a rear cooler 123. Under heavy load or high-temperature conditions, the rear EDU 122 may generate substantial heat, which can be dissipated directly via the rear cooler 123. However, this cooler can also be bypassed if the ambient environment is cold and the system seeks to preserve heat within the coolant loop. A valve 141 connects the rear drive circuit 120 to the main circuit 100 whenever additional heating or cooling capacity is needed. For instance, if the rear EDU becomes too warm, valve 141 can be opened so that coolant flows into the main circuit, taking advantage of front coolers 112 and 115 and the heat pump 119 (if it is in a cooling configuration). In colder conditions, this connection enables the rear drive circuit to draw upon warmed coolant from the main circuit, preventing the rear EDU from operating below its optimal temperature range.

[0039] The third coolant loop, the HV ESS circuit 130 (i.e. the battery circuit), is dedicated to the high-voltage energy storage system (HV ESS) 131. The HV ESS must be maintained within strict temperature limits for optimal performance and safety. A battery circuit pump 132 circulates coolant through the battery modules 131, a battery circuit cooler 133, and a battery circuit plate heat exchanger (battery circuit PHX) 134. Similar to the other coolers, the battery circuit cooler 133 can also be bypassed if ambient cooling is not desired, particularly in cold weather, so that the battery retains heat. However, if the HV ESS generates excessive heat during rapid charging or discharging, or if the ambient temperatures are high, then the battery circuit cooler 133 or even the front coolers 112 and 115 (via valves 142, 143) may be employed for faster heat dissipation.

[0040] When the HV ESS needs to warm up, for example in low ambient temperatures, the HV ESS circuit 130 can be fluidly coupled to the main circuit 100 by opening battery circuit valves 142 and 143. Warm coolant, generated by the high-voltage heater 111 or by the heat pump 119 in heating mode, is then transferred from the main circuit into the HV ESS circuit. This thermal energy raises the battery temperature closer to an ideal operating range, improving battery performance and longevity. Conversely, if the HV ESS is overheating, hot coolant can be directed toward the front coolers 112 and 115, or toward the battery circuit cooler 133, to ensure rapid and efficient dissipation of excess heat.

[0041] The flows within and between these circuits are orchestrated by a central controller 150, often the vehicle’s HVAC or thermal management controller. This controller 150 continuouslymonitors temperature data from sensors placed throughout the vehicle: within the EDUs, the battery modules, the DC-DC converter, each cooler, and the ambient environment. Based on these measurements, it can modulate speeds of pumps 116, 121, 132 and open or close the appropriate valves and bypass lines (including 141, 142, 143) in order to fine-tune thermal distribution. For instance, if the front EDUs, the rear EDU, and the battery are all generating excess heat, the controller 150 may open each relevant bypass or valve to push coolant through all available coolers. Conversely, in winter or cooler weather conditions, it may direct flow around some or all of the coolers 112, 115, and 123, retaining heat in the system for use by the battery or the passenger cabin.

[0042] The ability to bypass coolers when they are not needed provides a key efficiency benefit. Traditional cooling systems often force coolant through heat exchangers even when heat dissipation is unnecessary, resulting in energy losses and slower warm-up times. By including bypass pathways, the system eliminates the energy penalty associated with unneeded cooling, accelerates warm-up of both the battery and the EDUs, and enables the flexible recovery or rejection of heat. As a result, overall energy consumption for thermal management is reduced, and the vehicle experiences improved range and performance.

[0043] Exemplary Operational Scenarios

[0044] Scenario 1 : Winter Operation with Priority on Heating the Battery Modules

[0045] In a cold winter morning start-up, the high-voltage energy storage system is typically below its optimal operating temperature. Upon vehicle power-up, the central controller 150 detects the low battery temperature via sensors located in the HV ESS. The system then initiates a heating mode to bring the battery modules to an acceptable threshold (for instance, around 30°C).

[0046] To achieve this, the controller 150 activates the high-voltage heater 111 in the main circuit 100. Pump 116 circulates coolant past the high-voltage heater 111, raising the temperature of the coolant. At the same time, the controller 150 opens battery circuit valves 142 and 143, creating a fluid pathway from the warmed coolant in the main circuit to the HV ESS circuit 130. Pump 132 intheHVESS circuitthen draws this warmed coolant through the battery pack 131, transferring the heat to the battery modules.

[0047] Because the external air is cold, coolers 112, 115 in the main circuit are bypassed. Bypass lines or valves ensure that the coolant does not flow through these coolers, thereby preventing the valuable heat from dissipating to ambient. The front and rear EDUs might alsobe cooler than desired, so the controller 150 may selectively allow some heated coolant to circulate to these drive units. Meanwhile, the HVAC heat exchanger 110 can deliver warm air to the cabin if the driver has requested cabin heat. Thus, the system’s immediate priority is to ensure the HV ESS and other critical powertrain components reach a safe and efficient operating temperature, while also providing passenger comfort. Only once the HV ESS is sufficiently warm (and cabin temperatures are met) would any excess heat be diverted to the coolers or allowed to dissipate if necessary.

[0048] Scenario 2: Summer Operation with Priority on Cooling All Components

[0049] During summer, ambient temperatures can be high, and multiple vehicle components, such as the HV ESS, EDUs, and power electronics, may each require cooling to avoid thermal stress. In this scenario, the system typically relies on the front coolers 112, 115, the battery circuit cooler 133, and possibly the rear cooler 123, depending on which components are generating the most heat.

[0050] Initially, under a low power drive situation, such as cruising on a relatively flat highway, the vehicle power demands are moderate, and the EDUs and battery are not generating excessive heat. The central controller 150 may keep some coolers partially bypassed to reduce fluid resistance and pumping losses. For instance, the battery circuit cooler 133 might remain in standby if the HV ESS temperature is within acceptable limits. The EDUs 113, 114, and 122 may generate some heat, but not enough to require maximum cooling.

[0051] However, if the vehicle transitions into a high load scenario, such as climbing a steep grade in mountainous terrain, possibly with a heavily loaded truck application, the thermal demands escalate rapidly. The rear EDU 122, in particular, may generate significant heat while providing the necessary torque for climbing. Similarly, the front EDUs 113 and 114 and the HV ESS may experience higher heat generation as power draw increases.

[0052] In response, the central controller 150 detects rising temperatures through sensors located in the EDUs and battery pack. It opens the bypass valves leading to coolers 112, 115, and possibly 123 and 133 if more cooling capacity is needed. Speeds of pumps 116, 121, and 132 are increased as warranted to circulate coolant more quickly, enhancing heat transfer. The rear circuit valve 141 is opened to integrate the rear drive circuit 120 with the main circuit 100, allowing hot coolant from the rear EDU to flow into the main circuit where the large front coolers 112 and 115, along with the main heat pump 119 in cooling mode, can extract heat effectively. If the battery modules 131 are also experiencing elevated temperatures, valves 142 and 143 are opened to direct a portion of the coolant to the battery circuit cooler 133 and, ifneeded, to the main coolers 112, 115. In this manner, all major heat-generating components share a pooled cooling resource, maximizing efficiency and preventing any single component from overheating.

[0053] Once the vehicle returns to lower power demands (for instance, after cresting the mountain pass), the controller 150 may revert to a less aggressive cooling mode. This could involve partially bypassing one or more coolers again, thus reducing parasitic pumping losses and allowing the system to maintain normal operating temperatures without excessive energy consumption.

[0054] Overall, these two scenarios illustrate how the multi-circuit, multi-component thermal management system adapts fluid routing and heat exchange processes to match ambient conditions and real-time vehicle demands. By leveraging bypass lines around the coolers, selectively energizing the high-voltage heater or the heat pump, and coordinating pump speeds with valve positions, the system can efficiently heat or cool each component, particularly the HV ESS, thereby enhancing vehicle range, reliability, and occupant comfort in both cold and hot weather conditions.

[0055] While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the invention may be made. Therefore, the claimed invention as recited in the claims that follow is not limited to the embodiments described herein.

Claims

CLAIMS1. Athermal management system for an electric vehicle, comprising:a main circuit having a main pump configured to circulate coolant through a high-voltage heater, at least one cooler, and at least one electric drive unit;a supplementary circuit having a supplementary pump configured to circulate coolant through at least one supplementary electric drive unit and a supplementary cooler;a battery circuit having a battery circuit pump configured to circulate coolant through a high-voltage energy storage system;at least one supplementary circuit valve operable to selectively fluidly connect the supplementary circuit to the main circuit;at least one battery circuit valve operable to selectively fluidly connect the battery circuit to the main circuit; anda controller configured to regulate the pumps and valves so as to route coolant between the circuits based on thermal demands.

2. The thermal management system of claim 1, further comprising a battery circuit cooler disposed in the battery circuit, the battery circuit cooler being selectively bypassable to retain heat in cold ambient conditions or to enhance cooling in hot ambient conditions.

3. The thermal management system of claim 1 or 2, further comprising a battery circuit plate heat exchanger configured to exchange thermal energy between the battery circuit and the main circuit when the at least one battery circuit valve is open.

4. The thermal management system of any of claims 1 to 3, further comprising a main heat pump in fluid communication with the main circuit, and a main plate heat exchanger arranged to transfer heat between the coolant and an external refrigerant loop, wherein the controller is configured to operate the main heat pump in heating or cooling mode depending on detected temperatures.

5. The thermal management system of any of claims 1 to 4, wherein the main circuit further includes a DC-DC converter in fluid communication with the coolant, the DC-DC converter being cooled or heated by the main circuit to maintain an optimal operating temperature.

6. The thermal management system of any of claims 1 to 5, wherein the main circuit further comprises an HVAC heat exchanger for regulating passenger cabin temperature, the controller being configured to direct coolant through the HVAC heat exchanger in response to a cabin heating or cooling request.

7. The thermal management system of any of claims 1 to 6, wherein the at least one supplementary circuit valve is actuated by the controller in response to a threshold temperature of the at least one supplementary electric drive unit, thereby enabling coolant exchange between the supplementary circuit and the main circuit for enhanced heat rejection or heat retention.

8. The thermal management system of any of claims 1 to 7, wherein the at least one battery circuit valve is actuated by the controller in response to a threshold temperature of the high-voltage energy storage system, thereby enabling heated or cooled coolant from the main circuit to flow into the battery circuit.

9. The thermal management system of any of claims 1 to 8, wherein each of the main pump, the supplementary pump, and the battery circuit pump is a variable-speed pump, the controller being configured to modulate pump speed based on real-time thermal demands to reduce energy consumption.

10. The thermal management system of any of claims 1 to 9, wherein each cooler in the main circuit, supplementary circuit, and battery circuit includes at least one bypass line, the controller being configured to divert coolant around a given cooler when external cooling is not required, thereby minimizing unnecessary heat rejection and improving overall energy efficiency.

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