Air cooling heat dissipation system and control method of soft pack battery pack for drone

Abstract

The present invention discloses an air-cooling and heat dissipation system for a soft-pack battery pack for an unmanned aerial vehicle and a control method thereof. The air-cooling and heat dissipation system comprises a housing, a plurality of battery cells, a plurality of thermally conductive silicone pads and a temperature sensor arranged in the housing, an air inlet fan and an air outlet fan arranged outside the housing, and a controller; the temperature sensor, the air inlet fan, the air outlet fan, and the battery pack are all connected to the controller. The air-cooling and heat dissipation system of the present invention has a reasonable structural design, good heat dissipation effect, and can control the fan speed and the battery pack output power according to the battery pack temperature, so as to achieve the purpose of cooling the battery pack and keeping it within an appropriate temperature range, thereby ensuring the normal flight of the unmanned aerial vehicle.

Description

Technical Field

[0001] The present invention relates to the technical field of soft-pack battery packs for unmanned aerial vehicles, and in particular to an air-cooling heat dissipation system for a soft-pack battery pack for unmanned aerial vehicles and a control method thereof. Background Art

[0002] Compared with cylindrical batteries and square batteries, soft-pack battery packs have lighter shells and higher active material mass, so it is easier to achieve higher energy density. They are mainly used in some occasions that require high volume and weight of battery packs, such as drone battery packs.

[0003] However, in existing soft-pack battery packs, the cells are generally in close contact with each other, which has an adverse effect on the heat dissipation of the battery. In particular, in the case of high-rate discharge, the temperature often becomes too high.

[0004] At present, the heat dissipation methods of soft-pack battery packs generally include air cooling, water cooling, phase change materials, semiconductor refrigeration, etc. Both water cooling and semiconductor refrigeration require heavier heat dissipation modules, which is not conducive to giving full play to the advantages of high energy density of soft-pack batteries, and is not suitable for occasions with high weight requirements for battery packs. Phase change material is a better heat dissipation solution, but after the phase change material melts, it loses its heat absorption ability and is not suitable for long-term use. If air cooling is used, it is necessary to form air ducts between the batteries to increase the heat dissipation effect of air cooling. At present, most of the patents for soft-pack battery packs using air cooling use a frame structure to limit the position of the soft-pack batteries to achieve a certain gap between the batteries. However, this frame structure still brings more weight and is not suitable for certain occasions with high weight requirements. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide an air-cooled heat dissipation system for a soft-pack battery pack for an unmanned aerial vehicle and a control method thereof. The system has a reasonable structural design and good heat dissipation effect, and can control the fan speed and battery pack output power according to the battery pack temperature to avoid damage caused by overheating of the battery pack and affect the normal flight of the unmanned aerial vehicle.

[0006] The technical solution of the present invention is:

[0007] An air-cooled heat dissipation system for a soft-pack battery pack of a drone, comprising a housing, a plurality of single battery cells, a plurality of thermal conductive silicone pads and temperature sensors arranged in the housing, an intake fan and an exhaust fan arranged outside the housing, and a controller; the plurality of single battery cells form a battery pack, and a temperature sensor is arranged on the battery pack; a heat dissipation gap is left between two adjacent single battery cells, and a thermal conductive silicone pad is arranged in the heat dissipation gap; a row of vertically arranged and strip-shaped heat dissipation air holes are formed on each of the two opposite side plates of the housing, the heat dissipation air holes on the two side plates are opposite to each other one by one, and each heat dissipation gap is located between two opposite heat dissipation air holes; an intake fan is arranged outside one of the side plates of the housing provided with heat dissipation air holes and faces the outer wall of the side plate, and an exhaust fan is arranged outside the other side plate of the housing provided with heat dissipation air holes and faces the outer wall of the side plate; the temperature sensor, the intake fan, the exhaust fan and the battery pack are all connected to the controller.

[0008] Two thermal conductive silicone pads are arranged in the heat dissipation gap between two adjacent single battery cells, one of the thermal conductive silicone pads is located between the tops of two adjacent single battery cells, and the other thermal conductive silicone pad is located between the bottoms of two adjacent single battery cells.

[0009] The temperature sensor selects an NTC temperature sensor.

[0010] The temperature sensor is arranged on the surface of the single battery cell of the battery pack and is used to monitor the real-time temperature on the surface of the battery pack.

[0011] An air-cooled heat dissipation control method for a soft-pack battery pack of a drone specifically comprises the following steps:

[0012] (1), Firstly, set temperature thresholds T1, T2, T3, T4, the maximum fan speed N max , the maximum continuous discharge power P of the battery max and the minimum power P required for the attitude stability of the drone min in the controller, wherein, temperature threshold T1 < temperature threshold T2 < temperature threshold T3 < temperature threshold T4;

[0013] (2), The temperature sensor collects the real-time temperature T on the surface of the battery pack and transmits the collected real-time temperature T to the controller;

[0014] (3), When the real-time temperature T of the single battery cell < T1, the controller controls neither the intake fan nor the exhaust fan to start;

[0015] (4), When the real-time temperature T of the single battery cell satisfies T1 < T < T2, the controller controls the rotation speeds N of the intake fan and the exhaust fan to change with the temperature, and the rotation speed reaches the maximum rotation speed N at the temperature point of T2 max; In this stage, the rotational speeds of the intake fan and the exhaust fan increase linearly with temperature and conform to the following formula: N = N max *(T - T1) / (T2 - T1);

[0016] (5) The temperature threshold T3 is close to the maximum allowable temperature value during the operation of the battery pack. When the real-time temperature T of the battery cell satisfies T2 < T < T3, the controller controls the rotational speeds of the intake fan and the exhaust fan to maintain the maximum rotational speed N max ;

[0017] (6) The temperature threshold T4 is the maximum allowable temperature during the operation of the battery pack. When the real-time temperature T of the battery cell satisfies T3 < T < T4, the controller limits the output power of the battery pack to not exceed the maximum continuous discharge power P of the battery max , and the fan maintains the maximum rotational speed N max ; The temperature sensor monitors the rate of change of temperature with time dT / dt. When dT / dt > 0, the controller continues to reduce the output power of the battery pack, and the output power of the battery pack is always not lower than the minimum power P required for the attitude stability of the drone min ; When dT / dt < 0, the controller increases the output power of the battery pack, and the output power of the battery pack is always not higher than the maximum continuous discharge power P of the battery max ;

[0018] (7) When the real-time temperature T of the battery cell satisfies T > T4, the controller controls the rotational speeds of the intake fan and the exhaust fan to maintain the maximum rotational speed N max 、The output power of the battery pack remains at the minimum power P required for the attitude stability of the drone min , and at the same time, the controller issues an instruction to the battery protection board, issues an alarm for overheating of the battery, and controls the drone to land.

[0019] Advantages of the present invention:

[0020] (1) The structure of the air-cooled heat dissipation system of the present invention is simple, easy to maintain, economical and practical. The safety of lithium-ion battery use is improved through air-cooled heat dissipation, and the adverse effects of environmental factors on the use of lithium-ion batteries are reduced;

[0021] (2) Compared with the air-cooled heat dissipation systems of other soft-pack batteries, in the present invention, the battery cell monomers are separated by heat-conducting pads to form an air duct, avoiding the extra weight brought by the frame structure, and being able to better exert the advantages of high energy density of the soft-pack battery cells. Moreover, heat dissipation air holes are provided on the housing, and the heat dissipation air holes correspond to the heat-conducting gaps to ensure the smoothness of the air duct;

[0022] (3) The purpose of the control method of the present invention is not to reduce the temperature of the soft-pack battery pack as much as possible, but to keep the temperature of the soft-pack battery pack within an appropriate working range; and in order to ensure that the UAV can operate normally in the air, the present invention does not prevent the lithium-ion battery from overheating by interrupting the power supply like other lithium-ion batteries, but controls the fan speed and the battery pack output power to achieve the purpose of cooling the battery pack and keeping it within an appropriate temperature range, thereby ensuring the normal flight of the UAV. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the air-cooling heat dissipation system of the present invention.

[0024] Figure 2 It is a schematic structural diagram of the thermally conductive silicone pad of the present invention being arranged between battery cell monomers.

[0025] Figure 3 It is a structural schematic diagram of the housing of the present invention.

[0026] Figure 4 It is the control principle diagram of the present invention. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] See Figure 1-Figure 4, An air-cooled heat dissipation system for a soft-pack battery pack used in a drone, comprising a housing 1, a plurality of single battery cells 2, a plurality of thermal conductive silicone pads 3 and NTC temperature sensors 4 arranged inside the housing 1, an inlet air fan 5 and an outlet air fan 6 arranged outside the housing 1, and a controller 8; the plurality of single battery cells 2 form a battery pack, and NTC temperature sensors 4 are arranged on the surfaces of the single battery cells 2 of the battery pack, and the NTC temperature sensors 4 are used to monitor the real-time temperature on the surface of the battery pack; a heat dissipation gap is left between two adjacent single battery cells 2, and two thermal conductive silicone pads 3 are arranged in the heat dissipation gap between two adjacent single battery cells 2, one of the thermal conductive silicone pads 3 is located between the tops of two adjacent single battery cells 2, and the other thermal conductive silicone pad 3 is located between the bottoms of two adjacent single battery cells 2. A row of vertically arranged and strip-shaped heat dissipation air holes 7 are opened on each of the two opposite side plates of the housing 1, the heat dissipation air holes 7 on the two side plates are opposite to each other one by one, and each heat dissipation gap is located between two opposite heat dissipation air holes 7; an inlet air fan 5 facing the outer wall of the side plate is arranged outside one of the side plates of the housing 1 provided with the heat dissipation air holes 7, and an outlet air fan 6 facing the outer wall of the side plate is arranged outside the other side plate of the housing 1 provided with the heat dissipation air holes 7; the NTC temperature sensors 4, the inlet air fan 5, the outlet air fan 6, and the battery pack composed of the plurality of single battery cells 2 are all connected to the controller 8.

[0029] An air-cooled heat dissipation control method for a soft-pack battery pack used in a drone specifically comprises the following steps:

[0030] (1), First, set temperature thresholds T1, T2, T3, T4, the maximum fan speed N max , the maximum continuous discharge power P of the battery max and the minimum power P required for the attitude stability of the drone min in the controller 8, wherein, temperature threshold T1 < temperature threshold T2 < temperature threshold T3 < temperature threshold T4;

[0031] (2), The NTC temperature sensor 4 collects the real-time temperature T on the surface of the battery pack and transmits the collected real-time temperature T to the controller 8;

[0032] (3), When the real-time temperature T of the single battery cell < T1, the controller 8 controls neither the inlet air fan 5 nor the outlet air fan 6 to start;

[0033] (4), When the real-time temperature T of the single battery cell satisfies T1 < T < T2, the controller 8 controls the rotation speeds N of the inlet air fan 5 and the outlet air fan 6 to change with the temperature, and the rotation speeds reach the maximum rotation speed N at the temperature point of T2 max ; in this stage, the rotation speeds of the inlet air fan 5 and the outlet air fan 6 linearly increase with the temperature and conform to the following formula: N = N max * (T - T1) / (T2 - T1);

[0034] (5). The temperature threshold T3 is close to the maximum allowable temperature value during the operation of the battery pack. When the real-time temperature T of the battery cell satisfies T2 < T < T3, the controller 8 controls the rotational speeds of the intake fan 5 and the exhaust fan 6 to maintain the maximum rotational speed N. max ;

[0035] (6). The temperature threshold T4 is the maximum allowable temperature during the operation of the battery pack. When the real-time temperature T of the battery cell satisfies T3 < T < T4, the controller 8 limits the output power of the battery pack to not exceed the maximum continuous discharge power P of the battery. max , and the fan maintains the maximum rotational speed N. max The NTC temperature sensor 4 monitors the rate of change of temperature with time dT / dt. When dT / dt > 0, the controller 8 further reduces the output power of the battery pack, and the output power of the battery pack is always not lower than the minimum power P required for the attitude stability of the drone. min When dT / dt < 0, the controller 8 increases the output power of the battery pack, and the output power of the battery pack is always not higher than the maximum continuous discharge power P of the battery. max ;

[0036] (7). When the real-time temperature T of the battery cell satisfies T > T4, the controller 8 controls the rotational speeds of the intake fan 5 and the exhaust fan 6 to maintain the maximum rotational speed N. max . The output power of the battery pack remains at the minimum power P required for the attitude stability of the drone. min Meanwhile, the controller 8 issues an instruction to the battery protection board, issues an alarm for overheating of the battery, and controls the drone to land.

[0037] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A control method for an air-cooling heat dissipation system of a soft-pack battery pack for an unmanned aerial vehicle, characterized in that: The described air-cooled heat dissipation system includes a housing, a plurality of single battery cells, a plurality of thermal conductive silica gel pads, and temperature sensors disposed within the housing, an inlet air fan and an outlet air fan disposed outside the housing, and a controller; the plurality of single battery cells form a battery pack, and a temperature sensor is disposed on the battery pack; a heat dissipation gap is left between adjacent single battery cells, and a thermal conductive silica gel pad is disposed within the heat dissipation gap; a row of vertically arranged and elongated heat dissipation air holes are formed on each of the two opposite side plates of the housing, the heat dissipation air holes on the two side plates are opposite to each other one by one, and each heat dissipation gap is located between two opposite heat dissipation air holes; an inlet air fan is disposed outside one of the side plates of the housing provided with heat dissipation air holes and faces the outer wall of the side plate, and an outlet air fan is disposed outside the other side plate of the housing provided with heat dissipation air holes and faces the outer wall of the side plate; the temperature sensor, the inlet air fan, the outlet air fan, and the battery pack are all connected to the controller; The control method of the described air-cooled heat dissipation system specifically includes the following steps: (1) First, set temperature thresholds T1, T2, T3, T4, the maximum fan speed Nmax, the maximum continuous discharge power Pmax of the battery, and the minimum power Pmin required for the attitude stability of the drone in the controller, where temperature threshold T1 < temperature threshold T2 < temperature threshold T3 < temperature threshold T4; (2) The temperature sensor collects the real-time temperature T on the surface of the battery pack and transmits the collected real-time temperature T to the controller; (3) When the real-time temperature T of the single battery cell is < T1, the controller controls neither the inlet air fan nor the outlet air fan to start; (4) When the real-time temperature T of the single battery cell satisfies T1 < T < T2, the controller controls the speeds N of the inlet air fan and the outlet air fan to change with the temperature, and the speed reaches the maximum speed Nmax at the temperature point of T2; in this stage, the speeds of the inlet air fan and the outlet air fan linearly increase with the temperature and conform to the following formula: N = Nmax*(T - T1) / (T2 - T1); (5) The temperature threshold T3 is close to the maximum allowable temperature during the operation of the battery pack. When the real-time temperature T of the single battery cell satisfies T2 < T < T3, the controller controls the speeds of the inlet air fan and the outlet air fan to maintain the maximum speed Nmax; (6) The temperature threshold T4 is the maximum allowable temperature during the operation of the battery pack. When the real-time temperature T of the single battery cell satisfies T3 < T < T4, the controller limits the output power of the battery pack to not exceed the maximum continuous discharge power Pmax of the battery, and the fan maintains the maximum speed Nmax; the temperature sensor monitors the rate of change of temperature with time dT / dt. When dT / dt > 0, the controller further reduces the output power of the battery pack, and the output power of the battery pack is always not lower than the minimum power Pmin required for the attitude stability of the drone; when dT / dt < 0, the controller increases the output power of the battery pack, and the output power of the battery pack is always not higher than the maximum continuous discharge power Pmax of the battery; (7) When the real-time temperature T of the battery cell satisfies T>T4, the controller controls the speed of the air inlet fan and the air outlet fan to maintain the maximum speed Nmax, and the output power of the battery pack to maintain the minimum power Pmin required for the stability of the drone's attitude. At the same time, the controller sends a command to the battery protection board, issues a battery overheating alarm, and controls the drone to land.

2. The control method according to claim 1, characterized in that: Two thermally conductive silicone pads are arranged in the heat dissipation gap between two adjacent battery cells, one of which is located between the tops of the two adjacent battery cells, and the other is located between the bottoms of the two adjacent battery cells.

3. The control method according to claim 1, characterized in that: The temperature sensor is an NTC temperature sensor.

4. The control method according to claim 1, characterized in that: The temperature sensor is arranged on the surface of the battery cell monomer and is used to monitor the real-time temperature of the battery surface.

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