Active heating control method and device for motors based on phase change materials and automobiles

Abstract

This invention discloses a method, device, and vehicle for active heating control of a motor based on phase change materials. By adjusting the ratio of the d-axis to q-axis currents of the motor, the motor deviates from its optimal efficiency operation. The generated waste heat is transferred to the water circuit via the stator windings, where it is stored as latent heat using the phase change material. This latent heat is then supplied to components such as the battery through a circulating water circuit. The heat demand is dynamically corrected using a two-dimensional influence coefficient table, and stall heating or closed-loop control algorithm flow adjustment is implemented based on the vehicle's operating status to achieve a balance between power output and heat demand. The device includes a heat-insulated spiral water circuit phase change container, an integrated sensor network, and an intelligent control unit, working in conjunction with a heat pump system, prioritizing the use of waste heat from the motor for heating. This invention combines motor loss heat recovery with phase change energy storage technology, solving the problem of low battery heating efficiency in low-temperature environments for new energy vehicles. Simultaneously, the porous skeleton structure ensures the uniform thermal conductivity of the phase change material, achieving stable and constant temperature control.

Description

Technical Field

[0001] This invention belongs to the field of vehicle motor control, and particularly relates to a method, device and automobile for active heating control of motor based on phase change materials. Background Technology

[0002] From the perspective of my country's new energy vehicle development, the technological direction and trend of new energy vehicles are unshakable. New energy vehicles, especially electric vehicles, primarily rely on power batteries for their power, which directly impacts the vehicle's power performance and driving range. Their charging and discharging characteristics are significantly affected by temperature. Lithium-ion batteries retain 60%-70% of their capacity at 0℃, 40%-55% at -10℃, and 20%-40% at -20℃. This demonstrates the significant impact of temperature on battery capacity retention; the lower the temperature of an electric vehicle, the shorter its driving range. Therefore, in low-temperature environments, it is necessary to heat the battery pack to improve its charging and discharging performance.

[0003] Currently, heating solutions for pure electric vehicles in the market include PTC heating and heat pump technology. With increasing performance requirements for electric vehicles, heat pump technology has become a research hotspot due to its high-efficiency heating. Heat pumps absorb heat from outside the vehicle through refrigerant circulation and release it into the vehicle, thus raising the interior temperature. However, heat pump performance is limited at low temperatures, requiring supplemental heating elements such as PTC heaters. While this improves heating efficiency, it increases cost and weight, and the heat generated by the motor is not fully utilized, leading to increased energy consumption. Therefore, actively heating relevant components of the electric vehicle by controlling the motor to generate appropriate heating power has become a new technological trend. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned problems in the prior art and to provide a method, device and automobile for active heating control of motor based on phase change materials.

[0005] To achieve the above-mentioned technical objectives and effects, the present invention is implemented through the following technical solution:

[0006] A method for active heating control of an electric motor based on phase change materials includes:

[0007] Adjust the d-axis and q-axis currents of the motor to make the motor's drive efficiency deviate from the optimal efficiency output, thereby generating heat;

[0008] The heat is transferred to the water channel next to the motor through the stator winding, and then transported to the phase change material container through the water channel circulation.

[0009] By utilizing the latent heat of phase change of phase change materials, the heat transferred by the water circuit is stored, and when the temperature of the phase change material reaches a preset threshold, the heated water is delivered to the heat dissipation device of the new energy vehicle by a water pump to achieve active heating of specific parts.

[0010] Based on the vehicle's operating status and environmental parameters, the heat demand power is dynamically adjusted, and the theoretical heat demand value is corrected in real time through a two-dimensional table by combining the influence coefficients of phase change material temperature and water circuit temperature.

[0011] It monitors battery temperature, ambient temperature, and motor operating temperature in real time, and triggers or terminates the heating process based on preset temperature control logic.

[0012] Furthermore, the phase change material is preferably paraffin or molten salt.

[0013] Furthermore, the specific steps for dynamically adjusting the power demand for heat include:

[0014] When the vehicle is stationary, a stall heating method is used to fully allocate the motor output power to the power required for heat.

[0015] When the vehicle is in operation, based on the mechanical speed, load torque and electromagnetic torque requirements, the ratio of d-axis current to q-axis current is adjusted to generate preset heating power while meeting the power requirements.

[0016] Furthermore, a closed-loop control algorithm is introduced in the process of dynamically adjusting the power demand for heat, and the adjustment range of the d-axis current is corrected in real time according to the temperature deviation in order to balance the power output and the heat demand.

[0017] Furthermore, an overheat protection mechanism is set up so that when the temperature of the phase change material is detected to exceed 60°C, the motor heating is automatically cut off and the cooling cycle is started.

[0018] The present invention also provides an active heating device for an electric motor based on a phase change material, comprising:

[0019] The drive motor module is used to adjust the d-axis current and q-axis current to generate controllable heating power;

[0020] A phase change material container, connected to a water channel next to the motor, is used to store and release the latent heat of phase change;

[0021] The thermal circuit system, including a water pump, a heat dissipation device, and a circulating water circuit, is used to deliver water heated by the phase change material to the battery;

[0022] The control unit is used to dynamically adjust the heat output based on the vehicle's operating status, the temperature of the phase change material, and the water temperature in the water circuit, using a pre-calibrated system loss table and a two-dimensional influence coefficient table.

[0023] Temperature and flow sensors integrated into the thermal circuit system are used to collect water temperature, flow rate, and phase change material temperature data in real time and feed them back to the control unit.

[0024] Furthermore, the control unit has a built-in motor system loss table, which is generated by calibrating the functional relationship between motor current, voltage, torque and heat generation;

[0025] The two-dimensional influence coefficient table is generated through experimental calibration or optimization using machine learning algorithms. Specifically, under different combinations of ambient temperature and water temperature, the attenuation ratio of the heat demand of the phase change material is measured and fitted into a numerical relationship between K1 and K2.

[0026] Furthermore, the phase change material container is wrapped with a heat insulation layer and has a spiral water channel inside to prolong the heat exchange time between water and phase change material.

[0027] The present invention also provides a new energy vehicle, comprising:

[0028] The aforementioned active heating device for motors based on phase change materials is used to achieve efficient thermal management of batteries in low-temperature environments.

[0029] The device works in conjunction with the vehicle's heat pump system. When the ambient temperature is 10°C lower, the motor is activated first for active heating, while the PTC and heat pump system serve as auxiliary heating units.

[0030] Furthermore, the phase change material container is installed independently of the heat-requiring components, and heat loss is reduced through an insulation layer;

[0031] The heat-requiring components are equipped with heat-conducting plates, which are connected to the heat dissipation device via heat pipes to achieve uniform heat distribution.

[0032] The beneficial effects of this invention are:

[0033] This invention combines motor loss heat recovery with phase change energy storage technology, solving the problem of low battery heating efficiency in low-temperature environments for new energy vehicles. Simultaneously, a porous framework structure ensures uniform thermal conductivity of the phase change material, achieving stable temperature control. It fully utilizes the heat generated by the motor, effectively reducing power consumption; and by adjusting the d-axis and q-axis currents, it deviates from the optimal efficiency circle, simultaneously meeting the vehicle's heat and power requirements. Attached Figure Description

[0034] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0035] Figure 1 This is a flowchart of the method of the present invention;

[0036] Figure 2 This is the logic diagram of the motor's active heating state in this invention;

[0037] Figure 3 This is a correction diagram of the d-axis and q-axis currents of the drive motor in this invention.

[0038] Figure 4 This is the logic diagram for the correction of the influence coefficient to the system in this invention.

[0039] Figure 5 This is a schematic diagram of the phase change material container structure in this invention. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0041] like Figure 1 The method for active heating control of a motor based on phase change materials, as shown, specifically includes the following steps:

[0042] Step 1: Adjust the d-axis current and q-axis current of the motor to make the motor's drive efficiency deviate from the optimal efficiency output, so as to generate heat.

[0043] Step 2: The heat is transferred to the water path next to the motor through the stator winding, and then transported to the phase change material container through water circulation.

[0044] Among them, paraffin or molten salts are preferred as phase change materials.

[0045] The heat transfer process in a phase change material container includes:

[0046] During the heat absorption phase, the phase change material continuously absorbs heat from the water until its temperature reaches equilibrium with the water temperature.

[0047] After the motor stops supplying heat, the phase change material releases the stored latent heat, heats the water in the water circuit, and uses the heat dissipation device to maintain a constant temperature for the parts that need heat.

[0048] A porous framework structure is incorporated within the phase change material container to enhance the thermal conductivity uniformity of the composite phase change material.

[0049] Step 3: Utilize the latent heat of phase change of the phase change material to store the heat transferred by the water circuit, and when the temperature of the phase change material reaches a preset threshold, use a water pump to deliver the heated water to the heat dissipation device of the new energy vehicle to achieve active heating of specific parts.

[0050] Step 4: Based on the vehicle's operating status and environmental parameters, dynamically adjust the heat demand power, and combine the influence coefficients of phase change material temperature and water circuit temperature to correct the theoretical heat demand value in real time through a two-dimensional table.

[0051] The specific steps for dynamically adjusting the power demand for heat include:

[0052] When the vehicle is stationary, a stall heating method is used to fully allocate the motor output power to the power required for heat.

[0053] When the vehicle is in operation, based on the mechanical speed, load torque and electromagnetic torque requirements, the ratio of d-axis current to q-axis current is adjusted to generate preset heating power while meeting the power requirements.

[0054] A closed-loop control algorithm is introduced during the dynamic adjustment of heat demand power to adjust the d-axis current adjustment range in real time according to the temperature deviation, so as to balance power output and heat demand.

[0055] Step 5: Monitor battery temperature, ambient temperature, and motor operating temperature in real time, and trigger or terminate the heating process based on preset temperature control logic.

[0056] As a preferred embodiment of the present invention, an overheat protection mechanism can be set up so that when the temperature of the phase change material is detected to exceed 60°C, the motor heating is automatically cut off and the cooling cycle is started.

[0057] like Figure 2 As shown, the active heating judgment logic of the electric motor is as follows: First, the temperature of the component requiring heat should be judged. If the temperature is below 10℃, the motor will start active heating; otherwise, it will enter normal operation. Second, the vehicle's running status should be judged. If the vehicle is stationary, the motor will enter a stall state, at which time all electrical energy will be converted into heat energy to meet the heat demand of the vehicle's related components. If the vehicle is in motion, the motor will enter an active efficiency reduction heating state, adaptively deviating from the optimal efficiency circle to simultaneously meet the heat demand and power demand.

[0058] like Figure 3As shown, the calculation process for the d-axis and q-axis currents is as follows: First, the mechanical speed, load torque, and d- and q-axis voltages that meet the power requirements are collected. Since the power requirements are represented by electromagnetic torque, and it is strongly correlated with the d- and q-axis currents, the required electromagnetic torque is first formed using the mechanical speed and load torque. Then, the d- and q-axis currents at optimal efficiency are obtained using the mechanical speed and the two-axis voltages. At this point, a loss table exists within the motor, and this table should be generated by calibrating the functional relationship between motor current, voltage, torque, and heat generation. Simultaneously, the control unit sends the actual required heat generation power. By looking up the table, the d-axis current is adjusted to meet the heat requirements. Since the electromagnetic torque has not changed, the q-axis current output can be dynamically adjusted in real time through the closed-loop control system to meet the vehicle's power requirements. Thus, by adjusting the d- and q-axis currents to deviate from the optimal efficiency circle, both the vehicle's heat and power requirements are met.

[0059] The present invention also provides an active heating device for an electric motor based on a phase change material, comprising:

[0060] The drive motor module is used to adjust the d-axis current and q-axis current to generate controllable heating power.

[0061] The phase change material container is connected to the water channel next to the motor to store and release the latent heat of phase change. The phase change material container is wrapped with a heat insulation layer and has a spiral water channel inside to extend the heat exchange time between water and phase change material.

[0062] The thermal circuit system, including a water pump, a heat dissipation device, and a circulating water circuit, is used to deliver water heated by the phase change material to the battery;

[0063] The control unit dynamically adjusts heat output based on vehicle operating status, phase change material temperature, and water temperature, using a pre-calibrated system loss table and a two-dimensional influence coefficient table. The control unit incorporates a motor system loss table, generated by calibrating the functional relationship between motor current, voltage, torque, and heat generation. The two-dimensional influence coefficient table is generated through experimental calibration or machine learning algorithm optimization. Specifically, it measures the attenuation ratio of the phase change material's heat demand under different combinations of ambient and water temperatures and fits it to a numerical relationship between K1 and K2.

[0064] Temperature and flow sensors integrated into the thermal circuit system are used to collect water temperature, flow rate, and phase change material temperature data in real time and feed them back to the control unit.

[0065] like Figure 4As shown, the influence coefficients affect the heating power as follows: First, the temperature sensor and phase change material temperature sensor integrated into the thermal loop system are used to collect water temperature, flow rate, and phase change material temperature data in real time and feed them back to the control unit. Then, because the attenuation ratio of the heat demand of the phase change material varies under different combinations of ambient and water temperatures, the two-dimensional influence coefficient table (K1, K2) should be generated through experimental calibration or machine learning algorithm optimization to form the corresponding numerical relationship K, which is then integrated into the control unit. The influence coefficients are combined with the theoretical heating power demand to form the final actual heating power demand, which is then added to the q-axis current calculation as the final value.

[0066] like Figure 5 As shown, this embodiment provides a composite phase change material thermal storage container. The phase change material is selected from paraffin or molten salts. Structurally, it adopts a porous skeleton structure, which increases the contact area of ​​the heat transfer medium, ensuring uniform heat distribution and thus avoiding local overheating. The internal spiral water channel extends the heat exchange time, while the vacuum insulation layer reduces heat loss to the outside, improving energy storage efficiency.

[0067] The present invention also provides a new energy vehicle, comprising:

[0068] The aforementioned active heating device for motors based on phase change materials is used to achieve efficient thermal management of batteries in low-temperature environments.

[0069] The device works in conjunction with the vehicle's heat pump system. When the ambient temperature is 10°C lower, the motor is activated first for active heating, while the PTC and heat pump system serve as auxiliary heating units.

[0070] The phase change material container is installed independently of the heat-requiring components, and heat loss is reduced through an insulation layer.

[0071] The heat-requiring components are equipped with heat-conducting plates, which are connected to the heat dissipation device via heat pipes to achieve uniform heat distribution.

[0072] New energy vehicles also include a transmission system and a thermal management system:

[0073] In the transmission system, the motor outputs power through a reducer. Besides being output as mechanical energy, the remaining portion of its electrical energy is converted into heat energy and transferred to the water jacket connected to the motor. Simultaneously, the water jacket has a spiral water channel inside to extend the heat exchange time and transfers heat through a phase change material container, sending the heat generated by the motor into the vehicle's thermal management system, thus achieving the coupling effect between the motor's thermal energy and the thermal management system.

[0074] The vehicle thermal management system is a combination of the motor thermal management system, the cabin thermal management system, and the battery thermal management system, including components such as the motor water jacket, PTC heater, electric water pump, heat exchanger, and three-way valve. During operation, the motor generates heat, which is transferred through the water jacket to the phase change material container and then enters the water circulation system. The three-way valve regulates the proportion of heat entering the cabin and battery thermal management systems. Electrical energy output from the DC / DC converter is directly transferred to the PTC heater to generate heat, which is then transferred to the cabin and battery thermal management systems. The water pump ensures proper coolant flow in the water circuit. The heat generated by the cabin and battery thermal management systems is distributed to the engine compartment and battery via the heat exchanger.

[0075] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0076] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A method for active heating control of a motor based on phase change materials, characterized in that, include: Adjust the d-axis and q-axis currents of the motor to make the motor's drive efficiency deviate from the optimal efficiency output, thereby generating heat; The heat is transferred to the water channel next to the motor through the stator winding, and then transported to the phase change material container through the water channel circulation. By utilizing the latent heat of phase change of phase change materials, the heat transferred by the water circuit is stored, and when the temperature of the phase change material reaches a preset threshold, the heated water is delivered to the heat dissipation device of the new energy vehicle by a water pump to achieve active heating of specific parts. The control unit is used to dynamically adjust the heat demand power according to the vehicle's operating status and environmental parameters, and, in combination with the influence coefficients of the phase change material temperature and the water temperature in the water circuit, correct the theoretical heat demand value in real time through a two-dimensional table. Real-time monitoring of battery temperature, ambient temperature, and motor operating temperature; triggering or terminating the heating process based on preset temperature control logic. The control unit has a built-in motor system loss table, which is generated by calibrating the functional relationship between motor current, voltage, torque and heat generation. The control unit dynamically adjusts the heat output by using the pre-calibrated system loss table and two-dimensional influence coefficient table. The two-dimensional influence coefficient table is generated through experimental calibration or optimization using machine learning algorithms. Specifically, it measures the attenuation ratio of the heat demand of the phase change material under different combinations of ambient temperature and water temperature.

2. The method for active heating control of a motor based on phase change materials according to claim 1, characterized in that: The phase change material is preferably paraffin or molten salt.

3. The method for active heating control of a motor based on phase change materials according to claim 1, characterized in that, The specific steps for dynamically adjusting the heat demand power include: When the vehicle is stationary, a stall heating method is used to fully allocate the motor output power to the power required for heat. When the vehicle is in operation, based on the mechanical speed, load torque and electromagnetic torque requirements, the ratio of d-axis current to q-axis current is adjusted to generate preset heating power while meeting the power requirements.

4. The method for active heating control of a motor based on phase change materials according to claim 3, characterized in that, The process of dynamically adjusting the power demand for heat is introduced with a closed-loop control algorithm, which corrects the adjustment range of the d-axis current in real time according to the temperature deviation, so as to balance the power output and the heat demand.

5. A method for active heating control of a motor based on phase change materials according to any one of claims 1-4, characterized in that: An overheat protection mechanism is set up so that when the temperature of the phase change material is detected to exceed 60°C, the motor heating is automatically cut off and the cooling cycle is started.

6. An active heating device for a motor based on phase change materials, controlled by the control method described in claim 1, characterized in that, include: The drive motor module is used to adjust the d-axis current and q-axis current to generate controllable heating power; A phase change material container, connected to a water channel next to the motor, is used to store and release the latent heat of phase change; The thermal circuit system, including a water pump, a heat dissipation device, and a circulating water circuit, is used to deliver water heated by the phase change material to the battery; The control unit is used to dynamically adjust the heat output based on the vehicle's operating status, the temperature of the phase change material, and the water temperature in the water circuit, using a pre-calibrated system loss table and a two-dimensional influence coefficient table. Temperature and flow sensors integrated into the thermal circuit system are used to collect water temperature, flow rate, and phase change material temperature data in real time and feed them back to the control unit.

7. The active heating device for a motor based on phase change materials according to claim 6, characterized in that: The phase change material container is wrapped with a vacuum insulation layer and has a spiral water channel inside to prolong the heat exchange time between water and phase change material.

8. A new energy vehicle, characterized in that, include: The active heating device for a motor based on phase change material as described in any one of claims 6-7, so as to achieve efficient thermal management of batteries in low-temperature environments; The device works in conjunction with the vehicle's heat pump system. When the ambient temperature is 10°C lower, the motor is activated first for active heating, while the PTC and heat pump system serve as auxiliary heating units.

9. A new energy vehicle according to claim 8, characterized in that: The phase change material container is installed independently of the heat-requiring components, and heat loss is reduced through an insulation layer; The heat-requiring components are equipped with heat-conducting plates, which are connected to the heat dissipation device via heat pipes to achieve uniform heat distribution.

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