Cooling system of electric engine and electric propulsion device and aircraft applying cooling system

Abstract

The utility model provides a cooling system of an electric engine and application of the cooling system, the electric engine comprises a power motor and a motor controller, and the motor controller is integrated in the power motor; the cooling system comprises a flow channel, a first branch, a second branch and a flow channel control valve, the flow channel control valve is integrated in the motor controller, cooling liquid in the flow channel is divided into the first branch and the second branch through the flow channel control valve, and the flow channel control valve is used for controlling the flow of the cooling liquid in the first branch and the second branch. The cooling liquid flowing through the first branch is used for cooling the motor controller, and the cooling liquid flowing through the second branch is used for cooling the power motor. The motor controller and the power motor are independently cooled through cooling liquid flowing through the two branches connected in parallel, the flow of the cooling liquid of each branch is controlled through the flow channel control valves, it is ensured that the power motor and the motor controller are fully cooled, the cooling efficiency is improved, then the system operation efficiency is improved, and the heat dissipation requirement of a motor engine in an aircraft is met.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of aircraft technology, in particular to a cooling system of an electric motor and application thereof. BACKGROUND

[0002] The electric motor of an aircraft is affected by the ambient temperature and the power demand within the flight envelope of the aircraft and the emergency state power demand, and the system operating temperature rises with the increase of the output power. In order to improve the operating efficiency of the electric motor and prolong the peak power duration, the operating temperature of the electric motor is maintained in a suitable range by designing a cooling circuit.

[0003] In the related art, the motor controller and the power motor in the electric motor are arranged in series in the cooling circuit. The inventors have found that the cooling circuit does not meet the heat dissipation requirements of the electric motor in the aircraft, and therefore there is an urgent need to provide a cooling scheme suitable for the electric motor of the aircraft. CONTENT OF THE UTILITY MODEL

[0004] The present application provides a cooling system of an electric motor and application thereof to meet the heat dissipation requirements of the electric motor in the aircraft.

[0005] In a first aspect, the present application provides a cooling system of an electric motor, the electric motor comprising a power motor and a motor controller, the motor controller being integrated inside the power motor.

[0006] The cooling system of the electric motor comprises a flow channel, a first branch, a second branch and a flow channel control valve, the flow channel control valve being integrated inside the motor controller, the cooling liquid in the flow channel being divided into the first branch and the second branch through the flow channel control valve, the flow channel control valve being used to control the flow of the cooling liquid in the first branch and the second branch, the cooling liquid flowing through the first branch being used to cool the motor controller, and the cooling liquid flowing through the second branch being used to cool the power motor.

[0007] In a possible implementation, the flow channel control valve is designed with dual redundancy.

[0008] In a possible implementation, the flow channel control valve comprises a reset structure, the reset structure resetting when the flow channel control valve is in a non-powered state or a failure state, so that the flow of the cooling liquid in the first branch is less than the flow of the cooling liquid in the second branch.

[0009] In a possible implementation, the flow channel control valve comprises at least one of an electromagnetic valve, a three-way valve, a ball valve, a butterfly valve, a stop valve, a plug valve, a flow divider and a multi-channel valve.

[0010] In a possible implementation, the cooling liquid flowing through the first branch and the second branch is cooled by a radiator, and the cooling system of the electric motor further comprises a cooling assembly for cooling the radiator.

[0011] In a possible implementation, the heat dissipation assembly comprises a fan.

[0012] In a possible implementation, the electric motor cooling system further comprises: a control unit for controlling the flow passage control valve; a sensing assembly for collecting a motor temperature of the motor and a component temperature of a heat generating component of the motor controller; wherein the control unit is electrically connected with the sensing assembly, and the control unit is further connected with the flow passage control valve.

[0013] In a possible implementation, the control unit comprises a first comparator and a driving assembly, wherein: the first comparator is configured to compare the motor temperature and the component temperature collected by the sensing assembly; and the driving assembly is configured to generate a control signal for the opening of the flow passage control valve based on an output of the first comparator.

[0014] In a possible implementation, the control unit further comprises a second comparator and a third comparator, wherein: the second comparator is configured to compare the motor temperature and a motor over-temperature protection temperature; the third comparator is configured to compare the component temperature and a component over-temperature protection temperature; and the driving assembly is configured to generate the control signal for the opening of the flow passage control valve based on an output of at least one of the first comparator, the second comparator and the third comparator.

[0015] In a possible implementation, the control unit further comprises a communication device, and the communication device interacts with a flight control system, and the flight control system is configured to remotely monitor the cooling system of the electric motor.

[0016] In a possible implementation, the control unit is integrated in the motor controller, or the control unit is integrated in another control unit of the aircraft.

[0017] In a possible implementation, the heat generating component comprises a motor controller power device, and cooling of the motor controller power device is single-sided cooling or double-sided cooling.

[0018] In a second aspect, the application provides an electric motor, comprising a motor and a motor controller, the motor controller being integrated inside the motor, and the electric motor is integrated with the cooling system of the electric motor according to any one of the first aspect.

[0019] In a third aspect, the application provides an electric propulsion device, the electric propulsion device comprising the electric motor according to the second aspect.

[0020] In a fourth aspect, the application provides an aircraft, the aircraft comprising an aircraft body and the electric propulsion device according to the third aspect.

[0021] The cooling system of the electric motor and the application thereof are provided, the electric motor comprises a power motor and a motor controller, the motor controller is integrated in the power motor; the cooling system comprises a flow channel, a first branch, a second branch and a flow channel control valve, the flow channel control valve is integrated in the motor controller, the cooling liquid in the flow channel is divided into the first branch and the second branch through the flow channel control valve, the flow channel control valve is used for controlling the flow of the cooling liquid in the first branch and the second branch, the cooling liquid flowing through the first branch is used for cooling the motor controller, and the cooling liquid flowing through the second branch is used for cooling the power motor. By integrating the motor controller in the power motor, the size structure of the system is reduced, the heat dissipation management of the motor controller and the power motor is optimized, the flow channel control valve is integrated in the motor controller, the compactness and the response speed of the system can be improved, and the integration and maintenance of the system are facilitated. The motor controller and the power motor in the electric motor are independently cooled through the cooling liquid flowing through the two parallel branches, the flow of the cooling liquid in each branch is further controlled through the flow channel control valve, the power motor and the motor controller are ensured to be fully cooled, the cooling efficiency is improved, the system operation efficiency is improved, and the heat dissipation demand of the electric motor in the aircraft is met. In addition, the overheat of the power motor and the motor controller is avoided through efficient cooling, the service life of the power motor and the motor controller is prolonged, and the system stability and reliability are improved; the design of the two independent branches makes the system have good flexibility and scalability, and the flow of the cooling liquid in the branches can be increased or decreased according to different heat dissipation demands. BRIEF DESCRIPTION OF DRAWINGS

[0022] The drawings incorporated into the specification and constituting a part of the specification show embodiments consistent with the present application and, together with the specification, serve to explain the principles of the present application.

[0023] Figure 1 A structural schematic diagram of the cooling system of the electric motor provided for the exemplary embodiments of the present application is shown in the figure.

[0024] Figure 2 A flow distribution control schematic diagram of the flow channel control valve on the first branch and the second branch provided for the exemplary embodiments of the present application is shown in the figure.

[0025] Figure 3 A control unit block diagram of the cooling system of the electric motor provided for the exemplary embodiments of the present application is shown in the figure.

[0026] Reference signs:

[0027] 11: flow channel; 12: first branch; 13: second branch; 14: flow channel control valve; 15: motor controller; 16: power motor; 17: circulating pump; 18: radiator;

[0028] 21: electromagnetic valve body; 22: electromagnetic valve spool; 23: electromagnetic valve spring;

[0029] 30: control unit; 31: first comparator; 32: second comparator; 33: third comparator; 34: driving assembly.

[0030] The specific embodiments of the application have been shown and described in the above-described drawings and specification, it is to be understood that the application is not limited to the embodiments described, since modifications can be made by those skilled in the art, and still be within the scope of the application as defined by the appended claims. DETAILED DESCRIPTION

[0031] It should be noted that the terms "first", "second" and the like in the description do not necessarily connote an absolute order or quantity, but are used to differentiate one implementation from another. Thus, a feature defined with "first" or "second" can include at least one of the features. In the description, the meaning of "a plurality" is at least two, for example, two, three, etc., unless otherwise specifically defined.

[0032] In the present application, unless otherwise clearly specified and limited, the terms "mounting", "connecting", "fixing" and the like should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integral; can be directly connected, or indirectly connected through an intermediate medium; can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly specified and limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0033] In the present application, unless otherwise clearly specified and limited, the first feature is "on" or "under" the second feature, which can be direct contact between the first and second features, or indirect contact between the first and second features through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be directly above or obliquely above the second feature, or only means that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be directly below or obliquely below the second feature, or only means that the horizontal height of the first feature is less than that of the second feature.

[0034] In the above description, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, the person skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction.

[0035] First, the terms involved in the present application are explained:

[0036] Electric motor: a system composed of an electric motor, a motor controller, a cable and its accessories, which can convert electrical energy into mechanical energy.

[0037] Lift / thrust assembly: composed of an electric motor, a propeller and its accessories.

[0038] Electric propulsion device: composed of a power battery, an electric motor, a propeller and its accessories.

[0039] The electric motor of the aircraft has the characteristics of high integration. Compared with the electric vehicle, the cooling system of the electric motor is not connected with the on-board charger (OBC) controller and the DCDC converter cooling circuit, and the traditional multi-system and multi-attachment electric drive cooling is not suitable for the aviation electric motor (for example, the electric motor of the aircraft). In addition, the power device of the high-voltage motor controller of the electric motor is preferably a wide bandgap power semiconductor module, such as silicon carbide (SiC) and gallium nitride (GaN) semiconductor. Compared with the traditional silicon-based power semiconductor (MOSFET and IGBT), the wide bandgap semiconductor has the characteristics of low loss and high efficiency, and has better electrical and thermal performance. The wide bandgap power semiconductor module has lower heat dissipation, which is suitable for high-voltage electric motor, and the heat dissipation of the wide bandgap power semiconductor motor controller and the power motor is quite different, resulting in different cooling requirements. If the motor controller and the power motor in the electric motor are connected in series in the cooling circuit of the electric motor cooling system according to the prior art, the power motor and the motor controller in the electric motor with different cooling requirements cannot be cooled independently, to a certain extent, there is excessive cooling or incomplete cooling, resulting in low cooling efficiency of the system and poor cooling control effect. The electric motor of the aircraft has high requirements for accuracy, reliability and safety, therefore, the cooling circuit in the related art does not meet the heat dissipation requirements of the electric motor in the aircraft.

[0040] To solve the above technical problems, the application provides an electric motor cooling scheme, wherein a flow channel control valve is arranged in an electric motor cooling system to divide the cooling liquid flowing out of a circulating pump into two branches, the cooling liquid flowing through the first branch is used to cool the motor controller, and the cooling liquid flowing through the second branch is used to cool the power motor, so that independent cooling of the power motor and the motor controller is realized, the cooling liquid flow in each branch is controlled by the flow channel control valve, different cooling requirements of the power motor and the motor controller are met, and then the cooling efficiency is optimized, and the system operation efficiency is improved.

[0041] The technical scheme of the application and how the technical scheme of the application solves the above technical problems will be described in detail in specific embodiments. The following specific embodiments can be combined with each other, and the same or similar concepts or processes can not be described again in some embodiments. The embodiments of the application will be described below with reference to the drawings.

[0042] Figure 1 The structure diagram of the cooling system of the electric motor provided by the exemplary embodiments of the application is shown in the figure. Figure 1 As shown in the figure, the electric motor includes a power motor and a motor controller, the motor controller is integrated in the power motor, the cooling system provided by the exemplary embodiments of the application includes a flow channel 11, a first branch 12, a second branch 13 and a flow channel control valve 14, the flow channel control valve 14 is integrated in the motor controller 15, the cooling liquid in the flow channel 11 is divided into the first branch 12 and the second branch 13 through the flow channel control valve 14, the flow channel control valve 14 is used to control the cooling liquid flow in the first branch 12 and the second branch 13, the cooling liquid flowing through the first branch 12 is used to cool the motor controller 15, and the cooling liquid flowing through the second branch 13 is used to cool the power motor 16.

[0043] The motor controller 15 is integrated in the power motor 16, which can be understood as that the power motor 16 and the motor controller 15 are integrated in the same shell by adopting the common shell design, so that the size structure of the system is reduced, and the heat dissipation management of the motor controller 15 and the power motor 16 is optimized.

[0044] The back cover of the motor controller 15 integrates the flow channel 11, and the flow channel control valve 14 is integrated inside the motor controller 15. The flow channel 11 is connected to the inlet of the flow channel control valve 14, and the output end of the flow channel control valve 14 includes a first branch 12 and a second branch 13 in parallel. The first branch 12 is connected to the cooling flow channel of the heat-generating component of the motor controller 15, and the second branch 13 is connected to the cooling flow channel of the stator of the power motor 16 through a bypass flow channel. That is, the low-temperature coolant flowing out of the circulation pump 17 flows into the flow channel 11 and is divided into the first branch 12 and the second branch 13 by the flow channel control valve 14. The heat-generating components of the motor controller 15 are integrated on the cooling plate or indirectly attached to the outer surface of the tube wall of the cooling plate using heat-conductive material. The other side of the cooling plate is a cooling channel, which is connected to the first branch 12. The coolant in the first branch 12 flows through the cooling plate, removing the heat generated by the heat-generating components and cooling the motor controller 15. The second branch 13 is isolated from the motor controller 15 and does not cool the heat-generating components of the motor controller. The stator base plate of the power motor 16 has an integrated cooling channel, which is connected to the second branch 13. The coolant in the second branch 13 flows through the stator winding, dissipating the heat generated by the stator winding and cooling the power motor 16. The high-temperature coolant flowing out of the two branches is converged by the radiator 18 and then flows back to the circulation pump 17, where the heat of the high-temperature coolant is dissipated to the environment.

[0045] The flow channel control valve 14 is used to control the flow of the coolant in the first branch 12 and the second branch 13 .

[0046] The flow channel control valve 14 includes any one of a solenoid valve, a three-way valve, a ball valve, a butterfly valve, a stop valve, a plug valve, a diverter and a multi-channel valve.

[0047] In one example, the flow control valve 14 is regulated by a hardware circuit to change the coolant flow rate flowing into the first branch 12 and the second branch 13. For example, according to the heat dissipation requirements of the heat-generating components in the power motor and the motor controller, the flow control valve 14 is dynamically regulated to control the coolant flow rate of each branch. When the hardware circuit generates a high-level signal, the valve opening of the control flow control valve becomes larger. When the hardware circuit generates a low-level signal, the valve opening of the control flow control valve becomes smaller, thereby regulating the coolant flow rate of the first branch 12 and the second branch 13.

[0048] In another example, the flow channel control valve 14 is designed based on its own structural properties, for example, the structure of the return spring is designed to automatically reset the valve opening through the return spring.

[0049] It should be noted that the embodiment of the present application does not limit how the flow control valve 14 controls the coolant flow of branches one and two in the cooling system, and can be selected according to actual needs and scenarios.

[0050] It should be noted that the power motor 16 is arranged in the liquid cooling cavity, the cavity wall of the liquid cooling cavity has a liquid outlet and at least one liquid inlet, the liquid inlet is used for supplying the cooling liquid into the liquid cooling cavity, and the liquid outlet is used for supplying the cooling liquid in the liquid cooling cavity to flow out, the second branch 13 is communicated with the liquid supply channel of the liquid cooling cavity through the bypass pipeline, and the liquid supply channel is communicated with the liquid cooling cavity through the liquid inlet. The cooling liquid flowing into the liquid inlet is heat-conducted to the single winding or the multiple windings arranged in a circle through the annular cooling channel, and the power motor 16 can be designed as a single winding or a multiple winding. That is, the single winding or the multiple windings arranged in a circle are heat-conducted through the at least one annular cooling channel, and the heat generated by the windings is taken away.

[0051] The motor controller 15 can be designed as a dual-redundancy design or a single-redundancy design, if the motor controller 15 is designed as a dual-redundancy design, the dual-redundancy motor controller is arranged on two cooling plates.

[0052] In one example, one cooling plate is connected to one cooling channel, that is, the cooling liquid flowing out of the circulating pump 17 enters the channel 11, is branched to three parallel branches through the channel control valve 14, and the cooling liquid flowing through the three branches independently cools the first-redundancy motor controller, the second-redundancy motor controller and the power motor, so as to improve the heat dissipation effect of the motor controller 15 and improve the cooling efficiency.

[0053] In another example, two cooling plates share one cooling channel, the cooling liquid flowing out of the circulating pump 17 enters the channel 11, is branched to two parallel branches through the channel control valve 14, the cooling liquid flowing through one branch cools the dual-redundancy motor controller, and the cooling liquid flowing through the other branch cools the power motor; in another example, the cooling liquid flowing out of the circulating pump 17 enters the channel 11, is branched to two parallel branches through the channel control valve 14, the cooling liquid flowing through one branch can be further branched into two sub-branches, one sub-branch flows through the cooling plate of the first-redundancy motor controller, and the other sub-branch flows through the cooling plate of the second-redundancy motor controller, so as to take away the heat generated by the heat-generating components, improve the heat dissipation effect of the motor controller and improve the cooling efficiency.

[0054] The motor controller is integrated in the power motor, the size structure of the system is reduced, heat dissipation management of the motor controller and the power motor is optimized, the flow control valve is integrated in the motor controller, the compactness and response speed of the system are improved, and integration and maintenance of the system are facilitated. The motor controller and the power motor in the electric motor are cooled by the cooling liquid flowing through two parallel branches, independent cooling of the power motor and the motor controller is realized, the cooling liquid flow of each branch is controlled by the flow control valve, sufficient cooling of the power motor and the motor controller is ensured, cooling efficiency is improved, system operation efficiency is improved, and the heat dissipation requirement of the electric motor in the aircraft is met. In addition, through efficient cooling, overheating of the power motor and the motor controller is avoided, the service life of the power motor and the motor controller is prolonged, and the stability and reliability of the system are improved. The design of two independent branches makes the system have good flexibility and scalability, and the cooling liquid flow in the branches can be increased or decreased according to different heat dissipation requirements.

[0055] In some embodiments, the flow control valve is a dual-redundancy design.

[0056] For example, the output end of the circulating pump enters the flow channel of the motor controller through a cooling liquid pipeline, the flow channel is connected with the input end of the flow control valve A and the input end of the flow control valve B respectively, the output end (for example, A-1 branch) of the flow control valve A is connected with the cooling plate of the motor controller, and the output end (for example, A-2 branch) of the flow control valve A is connected with the stator winding cooling flow channel of the power motor. The output end (for example, B-1 branch) of the flow control valve B is also connected with the cooling plate of the motor controller, and the output end (for example, B-2 branch) of the flow control valve B is also connected with the stator winding cooling flow channel of the power motor, that is, the heat generating components of the motor controller are cooled and dissipated through the A-1 branch of the flow control valve A and the B-1 branch of the flow control valve B, and the stator winding of the power motor is cooled and dissipated through the A-2 branch of the flow control valve A and the B-2 branch of the flow control valve B.

[0057] Through the dual-redundancy flow control valve, when one flow control valve fails, the other flow control valve can still work normally, the heat dissipation requirement of the electric propulsion system of the aircraft is met, and the safety and reliability of the system are improved.

[0058] In some embodiments, the flow control valve includes at least one of an electromagnetic valve, a three-way valve, a ball valve, a butterfly valve, a stop valve, a plug valve, a flow divider and a multi-channel valve.

[0059] In one implementation, the flow passage control valve includes any one of a solenoid valve, a three-way valve, a ball valve, a butterfly valve, a stop valve, a plug valve, a flow divider, and a multi-channel valve. For example, the flow passage control valve is a two-position three-way solenoid valve, such as Figure 2 The flow passage control valve provided for the exemplary embodiments of the present application controls the flow distribution of the first branch and the second branch as shown in the schematic diagram. The two-position three-way solenoid valve includes a solenoid valve body 21, a solenoid valve spool 22, a solenoid valve spring 23, a flow passage 11, a first branch 12, and a second branch 13. The opening degree of the valve is controlled by the electromagnetic force generated by the solenoid coil, thereby controlling the flow of the coolant. As the solenoid valve spool 22 moves in the cavity, the flow of the coolant in the first branch 12 and the second branch 13 changes.

[0060] In another implementation, the flow passage control valve includes any combination of a solenoid valve, a three-way valve, a ball valve, a butterfly valve, a stop valve, a plug valve, a flow divider, and a multi-channel valve. For example, the flow passage control valve is a combination of a solenoid valve and a ball valve, which is applied to the scenario of a dual-redundancy flow passage control valve. The heat generating components of the motor controller are cooled by the A-1 branch of the solenoid valve A and the B-1 branch of the ball valve B, and the stator winding of the motor is cooled by the A-2 branch of the solenoid valve A and the B-2 branch of the ball valve B.

[0061] In some embodiments, the flow passage control valve includes a reset structure that resets when the flow passage control valve is in a non-powered state or a failure state, so that the flow of the coolant in the first branch is less than the flow of the coolant in the second branch.

[0062] For example, the reset structure of the flow passage control valve is optimized in advance. For example, when the flow passage control valve is a solenoid valve, the return spring is improved so that the solenoid valve spool is automatically maintained at a certain flow distribution opening degree when the solenoid valve is powered off or fails, i.e., mechanically reset to a fixed position.

[0063] In the first implementation, the reset structure is modified so that when the flow passage control valve is in a non-powered state or a failure state, the opening degree of the valve corresponding to the first branch is less than the opening degree of the valve corresponding to the second branch. The greater the opening degree, the greater the flow of the coolant, and the opening degree is between 0 and 100%.

[0064] Preferably, considering that the heat generation of the motor is usually greater than that of the motor controller, the opening degree of the valve corresponding to the first branch is 30%, and the opening degree of the valve corresponding to the second branch is 70%.

[0065] In the second implementation, the actual heat generation amount relationship between the power motor and the motor controller under the rated continuous power is obtained based on the type, model, actual application scenario, and the like of the power motor and the motor controller, and the return spring structure of the flow channel control valve is designed based on the actual heat generation amount relationship between the power motor and the motor controller, for example, the motor controller generates a large amount of heat, and the valve opening corresponding to the first branch flowing through the motor controller is designed to be large. When the flow channel control valve is in a non-powered state or a failure state, the return spring is automatically reset to a valve opening corresponding to the first branch flowing through the motor controller, which is larger than a valve opening corresponding to the second branch flowing through the power motor.

[0066] The embodiments of the present application ensure that the heat generating components of the power motor and the motor controller are cooled by the coolant circulating when the flow distribution of the coolant in each branch fails, and the cooling demand is maximally guaranteed to be met.

[0067] In some embodiments, the coolant flowing through the first branch and the second branch is cooled by the radiator, and the cooling system of the electric motor further includes a heat dissipation assembly for cooling the radiator.

[0068] The coolant of the first branch and the second branch absorbs heat of the motor controller and the power motor, and then flows into the radiator through the coolant pipeline. The high-temperature liquid becomes low-temperature liquid after heat exchange with the outside through the radiator, and the radiator end dissipates heat to the surrounding environment through air flow or other cooling medium.

[0069] The heat dissipation assembly includes a fan, a heat dissipation fin, a physical module containing a heat dissipation material or a heat conduction material, and the like. For example, the physical module is arranged on the surface, inside or any position of the radiator to absorb heat or conduct heat, improve heat conduction efficiency, and the heat conduction material includes heat conduction paste, heat conduction pad, heat conduction glue and the like, and the heat dissipation material includes phase change material, metal matrix composite and the like. The heat dissipation fin is a thin sheet attached to the main body of the radiator to increase the surface area and enhance the heat dissipation effect. It should be noted that the present application does not specifically limit the heat dissipation assembly.

[0070] The embodiments of the present application utilize the heat dissipation assembly to effectively manage heat of the radiator, accelerate heat exchange of the radiator, and further improve the performance and cooling efficiency of the cooling system of the electric motor.

[0071] In some embodiments, the heat dissipation assembly includes a fan.

[0072] The fan discharges hot air from the inside of the radiator or introduces cold air into the inside of the radiator by forced convection.

[0073] By forced convection, the fan accelerates air flow through the surface of the radiator, significantly improves the heat dissipation efficiency, and is particularly suitable for high-power aircraft applications.

[0074] In some embodiments, the cooling system of the electric motor further comprises: a control unit for controlling the flow passage control valve; and a sensing assembly for collecting the motor temperature of the motor and the component temperature of the heat generating components of the motor controller; wherein the control unit is electrically connected with the sensing assembly, and the control unit is also connected with the flow passage control valve.

[0075] The sensing assembly comprises temperature sensors such as thermocouples, thermistors, infrared temperature sensors, and semiconductor temperature sensors.

[0076] The control unit comprises a hardware control unit such as a microcontroller, a programmable logic controller, etc., and can also be a special-purpose control unit such as a flight control computer, a microcomputer, etc.

[0077] For example, the sensing assembly comprises a motor temperature sensor and a component temperature sensor. The motor temperature sensor is installed inside or on the surface of the motor for real-time monitoring of the motor temperature, and the component temperature sensor is installed on the heat generating components (such as inverter power modules) of the motor controller for real-time monitoring of the temperature of these components. The control unit is connected with the sensing assembly in a wired or wireless manner. The wired connection is achieved through wires or cables, including I2C, SPI, UART, etc. interfaces, and the wireless connection is achieved using wireless technologies such as Wi-Fi, Bluetooth, Zigbee. The control unit and the sensing assembly further transmit temperature data through analog signals (voltage signals and current signals), digital signals (such as CAN bus, RS485 bus, Modbus protocol, etc.), or other wireless communication methods. The control unit is also electrically connected with the flow passage control valve.

[0078] In the embodiments of the present application, the control unit and the sensing assembly are arranged in the cooling system of the electric motor, so as to efficiently manage heat and ensure that the motor and the controller operate in an optimal state, thereby improving the overall working performance and efficiency.

[0079] In some embodiments, the control unit is designed in a dual-redundancy manner, and the flow passage control valve is designed in a single-redundancy manner.

[0080] For example, the dual-redundancy control unit is electrically connected with the flow passage control valve.

[0081] When both the dual-redundancy control units are normal, the valve opening degree of the flow passage control valve is controlled by a first redundancy control unit. When the first redundancy control unit fails, a second redundancy control unit is switched to control the valve opening degree of the flow passage control valve, so as to ensure the continuous and stable operation of the flow passage control valve.

[0082] In some embodiments, the control unit is designed in a dual-redundancy manner, and the flow passage control valve is designed in a dual-redundancy manner.

[0083] The first redundancy control unit is connected with the first redundancy flow channel control valve, the second redundancy control unit is connected with the second redundancy flow channel control valve, and the dual-redundancy control unit independently controls the corresponding flow channel control valve. When the first redundancy control unit fails, the valve opening degree of the second redundancy flow channel control valve is controlled by the second redundancy control unit, and the opening degree of each branch cooling liquid flow is increased, so as to ensure the stable operation of the cooling system of the motor generator and meet the heat dissipation demand of the motor generator.

[0084] In some embodiments, the control unit comprises a first comparator and a driving component, wherein: the first comparator is configured to compare the motor temperature and the component temperature collected by the sensing component; and the driving component is configured to generate a control signal for the opening degree of the flow channel control valve based on the output of the first comparator.

[0085] The input terminals of the first comparator are connected to the motor temperature sensor signal and the component temperature sensor signal, respectively. When the positive input voltage is higher than the negative input voltage, the comparator outputs a high-level signal. When the positive input voltage is lower than the negative input voltage, the comparator outputs a low-level signal. Optionally, the input terminal signals of the comparator can also be connected to the signals amplified in amplitude, for example, the positive input terminal of the first comparator is connected to the real motor temperature sensor signal (40℃), and the negative input terminal is connected to the component temperature sensor signal amplified in amplitude (50℃+ threshold range), so that the judgment condition of the comparator is more diversified, the heat dissipation demand of the motor and the motor controller is more refined, and the cooling liquid flow of the branch passing through the motor and the motor controller is accurately controlled.

[0086] The driving component generates different control signals based on the output of the first comparator. The driving component is connected to the flow channel control valve through a driving circuit, sends the control signal to the flow channel control valve through the driving circuit, and the flow channel control valve controls the valve opening degree according to the control signal, and then changes the cooling liquid flow distribution of different branches.

[0087] The control signal is generated by a hardware circuit, the flow channel control valve is dynamically controlled, the cooling liquid flow passing through the motor and the motor controller is accurately controlled, the cooling effect is optimized, the high-flow and high-efficiency cooling control is performed on the high-heat devices, the low-flow and low-efficiency cooling control is performed on the low-heat devices, the system operation efficiency is improved, and the temperature of the motor and the motor controller is ensured to be within a safe range, thereby improving the reliability and performance of the system.

[0088] To further improve the accuracy of the flow distribution of the different branches of the cooling liquid, in some embodiments, the control unit further comprises a second comparator and a third comparator, wherein: the second comparator is configured to compare the motor temperature and the motor over-temperature protection temperature; the third comparator is configured to compare the component temperature and the component over-temperature protection temperature; and the driving assembly is further configured to generate a control signal for the opening of the flow passage control valve based on the output of at least one of the first comparator, the second comparator, and the third comparator.

[0089] For example, Figure 3 A control unit block diagram of the cooling system of the electric motor provided by the exemplary embodiments of the present application is shown in FIG. 3. Figure 3 As shown in FIG. 3, the control unit 30 comprises a first comparator 31, a second comparator 32, a third comparator 33, and a driving assembly 34. The input terminals of the first comparator 31 are connected to the motor temperature sensor signal and the component temperature sensor signal, respectively. The input terminals of the second comparator 32 are connected to the motor temperature sensor signal and the motor over-temperature protection temperature signal, respectively. The input terminals of the third comparator 33 are connected to the component temperature signal and the component over-temperature protection temperature signal, respectively. When the positive input voltage is higher than the negative input voltage, the comparator outputs a high-level signal. When the positive input voltage is lower than the negative input voltage, the comparator outputs a low-level signal. Optionally, the input terminal signals of the comparator can also be connected to the signals after amplitude amplification. For example, the positive input terminal of the first comparator is connected to the actual motor temperature sensor signal (40°C), and the negative input terminal is connected to the component temperature sensor signal after amplitude amplification (50°C+threshold range), so that the judgment conditions of the comparator are more diversified, the heat dissipation requirements of the motor and the motor controller are more refined, and the flow of the cooling liquid in the flow passage where the motor and the motor controller are located is accurately controlled.

[0090] The driving assembly 34 generates different control signals based on at least one of the level signals output by the first comparator 31, the second comparator 32, and the third comparator 33. The driving assembly 34 is connected to the flow passage control valve 14 through a driving circuit, and sends the control signal to the flow passage control valve 14 through the driving circuit. The flow passage control valve 14 controls the opening of the valve according to the control signal, and thus changes the flow distribution of the cooling liquid.

[0091] In an example, when the voltage at the positive input terminal of the first comparator 31 (motor temperature) is higher than the voltage at the negative input terminal (component temperature), the first comparator 31 outputs a high-level signal, and vice versa. The driving assembly 34 generates a control signal based on the high or low level signal. The control signal includes controlling the valve opening corresponding to the second branch flowing through the motor to be greater than the valve opening corresponding to the first branch flowing through the motor controller, or controlling the valve opening corresponding to the second branch flowing through the motor to be less than the valve opening corresponding to the first branch flowing through the motor controller.

[0092] In another example, the first comparator 31 outputs a high level signal, and the third comparator 33 outputs a high level signal, i.e., the motor temperature is greater than the component temperature, the component temperature is greater than the component over-temperature protection temperature, the driving assembly 34 generates a control signal based on the outputs of the first comparator 31 and the third comparator 33, the control signal includes controlling the valve opening degree corresponding to the first branch flowing through the motor controller to be greater than the valve opening degree corresponding to the second branch flowing through the power motor, and the driving circuit drives the flow passage control valve according to the driving signal to control the coolant flow rate of the first branch flowing through the heat generating component to be greater than the coolant flow rate of the second branch flowing through the power motor.

[0093] In yet another example, the first comparator 31 outputs a low level signal, the second comparator 32 outputs a high level signal, and the third comparator 33 outputs a high level signal, i.e., the motor temperature is less than the component temperature, the motor temperature is greater than the motor over-temperature protection temperature, and the component temperature is greater than the component over-temperature protection temperature, the driving assembly 34 generates a control signal based on the outputs of the first comparator, the second comparator, and the third comparator, the control signal includes controlling the valve opening degree corresponding to the first branch flowing through the motor controller to be equal to the valve opening degree corresponding to the second branch flowing through the power motor, and the driving circuit drives the flow passage control valve according to the driving signal to control the coolant flow rate of the first branch flowing through the heat generating component to be equal to the coolant flow rate of the second branch flowing through the power motor.

[0094] It should be noted that the judgment conditions of the comparators and the control signals in the embodiments of the present application are not limited to the above-mentioned examples, and can be formulated according to actual scenes and needs, and the judgment conditions of the comparators and the control signals are not specifically limited in the present application.

[0095] In the embodiments of the present application, multiple comparators are arranged in the control unit to accurately judge the sizes of the motor temperature and the component temperature, so that the driving assembly generates a control signal with high accuracy, thereby accurately controlling the opening degree of the flow passage control valve. In addition, the flow passage control valve is dynamically controlled to accurately control the coolant flow rates flowing through the power motor and the motor controller, optimize the cooling effect, perform high-flow and high-efficiency cooling control on the high-heat devices, and perform low-flow and low-efficiency cooling control on the low-heat devices, thereby improving the system operation efficiency, and further ensuring that the temperatures of the power motor and the motor controller are within a safe range, and improving the reliability and performance of the system.

[0096] In some embodiments, the control unit is integrated in the motor controller, or the control unit is integrated in other control units of the aircraft.

[0097] It can be understood that when the control unit is integrated in other control units of the aircraft, the control unit and the motor controller exist independently.

[0098] The control unit is integrated in the motor controller, which can be regarded as the control unit being integrated in the main control board of the motor controller. For example, the control unit is designed as a control chip in the circuit board of the motor controller, which can improve the compactness and response speed of the system, and facilitate the integration and maintenance of the system. Integrating the control unit in other control units (such as the central controller or system management controller of the aircraft) can improve the flexibility and modular design of the system, and facilitate the expansion and maintenance of the system.

[0099] It should be noted that in actual application, the actual application requirements and system requirements should be weighed and selected, and efficient control of the cooling liquid flow distribution of the power motor and the motor controller can be realized by any way, thereby improving the reliability and performance of the system.

[0100] Further, in some embodiments, when the control unit is integrated in the motor controller, the main control board in the motor controller interacts with the flight control system; when the control unit is integrated in other control units of the aircraft, the control unit further comprises a communication device, the communication device interacts with the flight control system, and the flight control system is used for remotely monitoring the cooling system of the electric motor.

[0101] For example, the communication device comprises a collector and a transmitter, the collector is connected with the flow passage control valve, the circulating pump, the fan and the sensing assembly, the collector collects the operating states of the flow passage control valve, the circulating pump and the fan, and the motor temperature of the power motor and the component temperature of the heating component, and the transmitter is connected with the gateway of the flight control system, the transmitter sends the motor temperature of the power motor and the component temperature of the heating component, and the operating states of the flow passage control valve, the circulating pump and the fan to the flight control system (such as a flight control computer).

[0102] It should be noted that when the control unit is integrated in the motor controller, the electric motor cooling system does not directly interact with the flight control system, the flight control system interacts with the motor controller, and the control unit can be regarded as the main control module of the motor controller, and the required cooling liquid flow of the power motor and the motor controller in the electric motor cooling system is determined by the motor controller.

[0103] The embodiments of the present application can effectively monitor the operating state of the electric motor cooling system, discover system faults in time, and facilitate relevant personnel to master the current state of the electric motor cooling system.

[0104] In some embodiments, the heating component comprises a motor controller power device, and the cooling of the motor controller power device is single-sided cooling or double-sided cooling.

[0105] The single-sided cooling includes cold plate cooling or substrate cooling. The motor controller power device in the electric motor is usually a wide band gap power semiconductor device, such as a silicon carbide (SiC) or a gallium nitride (GaN) power semiconductor module. The motor controller power device includes an inverter module corresponding to a motor controlled by the motor controller, for example, a power motor inverter module, a pitch motor inverter module, a fan motor inverter module, and the like.

[0106] In an implementation manner, the motor controller power device can be mounted or integrated on a cooling plate, and the other side of the cooling plate is cooled by absorbing heat of the cooling liquid in the cooling flow channel, that is, cold plate cooling.

[0107] In another implementation manner, the cooling liquid directly contacts the motor controller power device through an interface material with high thermal conductivity to form a substrate cooling scheme, for example, the motor controller power device is directly mounted on a substrate made of metal ceramic, and the other side of the substrate is cooled by absorbing heat of the cooling liquid in the cooling flow channel.

[0108] In another implementation manner, the upper and lower surfaces of the motor controller power device are respectively mounted on the cooling plate or the substrate, and the two surfaces are simultaneously cooled.

[0109] It should be noted that different liquid cooling forms have their own scenes, advantages and disadvantages, and the appropriate liquid cooling form can be selected according to the specific application demand, thermal management requirement and system design.

[0110] According to the embodiments of the present application, the cooling system of the electric motor supports multiple liquid cooling forms in structure, and the liquid cooling form can be flexibly selected according to actual demand, and the flexibility is high.

[0111] In summary, the present application has at least the following advantages:

[0112] I. By integrating the motor controller in the power motor, the size structure of the system is reduced, the heat dissipation management of the motor controller and the power motor is optimized, the flow channel control valve is integrated in the motor controller, the compactness and response speed of the system can be improved, and the integration and maintenance of the system are facilitated. The motor controller and the power motor in the electric motor are cooled by the cooling liquid flowing through two parallel branches, the independent cooling of the power motor and the motor controller is realized, the cooling liquid flow through each branch is controlled through the flow channel control valve, the power motor and the motor controller are ensured to be fully cooled, the cooling efficiency is improved, the system operation efficiency is improved, and the heat dissipation demand of the electric motor in the aircraft is met. In addition, by means of efficient cooling, the power motor and the motor controller are prevented from overheating, and the service life of the power motor and the motor controller is prolonged, thereby improving the stability and reliability of the system. The design of two independent branches makes the system have good flexibility and scalability, and the cooling liquid flow in the flow channel can be increased or decreased according to different heat dissipation demands.

[0113] II. By means of the dual-redundancy flow channel control valve, when one flow channel control valve fails, the other flow channel control valve can still work normally to meet the heat dissipation requirement of the electric propulsion system of the aircraft, and improve the safety and reliability of the system.

[0114] III. By means of the modification of the reset structure contained in the flow channel control valve, when the flow distribution of the cooling liquid fails, the heat generating components of the power motor and the motor controller can be cooled by the circulating cooling liquid, and the heat dissipation requirement is maximally guaranteed.

[0115] IV. The heat dissipation assembly is used to realize the effective management of heat by the radiator, accelerate the heat exchange of the radiator, and thus improve the performance and cooling efficiency of the electric motor cooling system.

[0116] V. Multiple comparators are arranged in the control unit to accurately determine the sizes of the motor temperature and the component temperature, so that the driving assembly generates a control signal with high accuracy, thereby accurately controlling the opening degree of the flow channel control valve. In addition, the flow channel control valve is dynamically controlled to accurately control the flow of the cooling liquid through the power motor and the motor controller, optimize the cooling effect, and perform high-flow and high-efficiency cooling control on the high-heat devices and low-flow and low-efficiency cooling control on the low-heat devices, thereby improving the system operation efficiency and guaranteeing that the temperature of the power motor and the motor controller is within a safe range, and improving the reliability and performance of the system.

[0117] The above embodiments introduce the structure and implementation mode of the electric motor cooling system, and the application further provides an electric motor, which comprises a power motor and a motor controller, the motor controller is integrated in the power motor, and the electric motor is integrated with the above electric motor cooling system.

[0118] The cooling system of the electric motor is applied to the electric motor, can meet the heat dissipation requirement of the electric motor, maintains the working temperature of the electric motor in a proper range, improves the performance of the electric motor, improves the system operation efficiency of the electric motor, realizes safe, stable and efficient flight, in addition, the electric motor cooling system has high cooling efficiency, prevents the electric motor and its components from being damaged due to overheating, and thus prolongs the service life of the equipment.

[0119] The application further provides an electric propulsion device, which comprises the above electric motor.

[0120] The electric propulsion device is composed of a power battery, an electric motor, a propeller and the like and accessories thereof, the electric propulsion device using the above electric motor has significantly improved system performance and operation efficiency, and prolonged service life of the equipment.

[0121] The application further provides an aircraft, which comprises an aircraft body and the above electric propulsion device.

[0122] The aircraft using the above electric propulsion device realizes safe, stable and efficient flight.

[0123] It should be understood that many variations can be made in the application described and shown which should be within the skill of those in the art. It is therefore contemplated to cover any variations, uses, or adaptations of the application following, in general, the principles of the application and including such departures from the present disclosure as come within known or customary practice in the art to which the application pertains and fall within the limits of the appended claims. The scope of the application is solely by the appended claims.

Claims

1. A cooling system for an electric motor characterized by, The electric motor includes a power motor and a motor controller, the motor controller is integrated inside the power motor; The cooling system includes a flow channel, a first branch, a second branch and a flow channel control valve, the flow channel control valve is integrated inside the motor controller, the cooling liquid in the flow channel is divided into the first branch and the second branch through the flow channel control valve, the flow channel control valve is used for controlling the flow of the cooling liquid in the first branch and the second branch, the cooling liquid flowing through the first branch is used for cooling the motor controller, and the cooling liquid flowing through the second branch is used for cooling the power motor.

2. The cooling system of an electric motor generator according to claim 1, characterized by, The flow channel control valve is designed with double redundancy.

3. The cooling system of an electric motor generator according to claim 1, characterized by, The flow channel control valve includes a reset structure, which resets when the flow channel control valve is in a non-powered state or a failure state, so that the flow of the cooling liquid in the first branch is less than that in the second branch.

4. The cooling system of an electric motor-generator according to any one of claims 1 to 3, characterized by, The cooling liquid flowing through the first branch and the second branch is cooled by a radiator, and the cooling system further includes a heat dissipation assembly for cooling the radiator.

5. The cooling system of an electric motor generator according to claim 4, wherein The heat dissipation assembly includes a fan.

6. The cooling system of an electric motor-generator according to any one of claims 1 to 3, characterized by, Further comprising: a control unit for controlling the flow channel control valve; a sensing assembly for collecting the motor temperature of the power motor and the component temperature of the heat generating component of the motor controller; wherein the control unit is electrically connected with the sensing assembly, and the control unit is also connected with the flow channel control valve.

7. The cooling system of an electric motor generator according to claim 6, wherein The control unit includes a first comparator and a driving assembly, wherein: the first comparator is used for comparing the motor temperature and the component temperature collected by the sensing assembly; the driving assembly is used for generating a control signal for the opening of the flow channel control valve based on the output of the first comparator.

8. The cooling system of an electric motor generator according to claim 7, wherein The control unit further includes a second comparator and a third comparator, wherein: the second comparator is used for comparing the motor temperature and the motor over-temperature protection temperature; the third comparator is used for comparing the component temperature and the component over-temperature protection temperature; the driving assembly is also used for generating a control signal for the opening of the flow channel control valve based on the output of at least one of the first comparator, the second comparator and the third comparator.

9. The cooling system of an electric motor generator according to claim 7, wherein The control unit further includes a communication device, which interacts with a flight control system, and the flight control system is used for remotely monitoring the cooling system of the electric motor.

10. The cooling system of an electric motor generator according to claim 6, wherein The control unit is integrated in the motor controller, or the control unit is integrated in other control units of the aircraft.

11. The cooling system of an electric motor generator according to claim 6, wherein The heat generating component includes motor controller power devices, and the cooling of the motor controller power devices is single-sided cooling or double-sided cooling.

12. An electric motor characterized by The electric motor includes a power motor and a motor controller, the motor controller is integrated inside the power motor, and the electric motor is integrated with the cooling system of the electric motor as claimed in any one of claims 1 to 11.

13. An electric propulsion device, characterized by The electric propulsion device includes the electric motor as claimed in claim 12.

14. An aircraft characterized by, The aircraft includes an aircraft body and the electric propulsion device as claimed in claim 13.

Images