A power distribution system and power supply pod for aviation unmanned aerial vehicle

Abstract

The present invention discloses an aviation UAV power distribution system, including a power generation unit, a power distribution control unit, an energy storage unit and an electrical load; the output power of the power generation unit follows the power demand of the electrical load, and the energy storage unit balances the power difference between the power demand of the electrical load and the output power of the power generation unit; wherein: the electrical load includes a passive load and an active load, and the power distribution control unit controls the opening or closing of the active load according to the power difference. During the power demand switching process of the electrical load, when the power demand suddenly increases, the present invention can instantly provide power to ensure the stability of the operation of the electrical load, and when the power demand suddenly drops, it can instantly absorb power to prevent the power generation unit from running away, thereby ensuring the normal use of the electrical load and the power generation unit. The present invention also provides a power supply pod including the above-mentioned power distribution system.

Description

Technical Field

[0001] The invention relates to a power distribution system, in particular to an aviation unmanned aerial vehicle power distribution system and a power supply pod. Background Art

[0002] At present, after years of development, drone technology has developed into an important air force. The existing drones are mainly used in military and civilian fields, such as express delivery, disaster search and rescue, low-altitude reconnaissance and other application manufacturers. At present, in addition to the power consumption of the flight platform, drone platforms often carry application payloads for various practical scenarios. With the continuous increase in the demand for high altitude and long flight time, the onboard battery can no longer meet the use needs. Therefore, drones are currently equipped with power pods.

[0003] Since the power supply demand of the power load will change with the actual situation during the actual operation of the aerial drone, the power generation power of the power supply pod also needs to change with the power demand. For example, a power distribution method, device and system are disclosed in Chinese patent document CN113306727A. Receive the power supply demand of the current load channel; wherein the power supply demand of the current load channel is obtained by the flight control device of the drone according to the operating state of the drone; generate a demand control instruction according to the power supply demand; obtain the actual power of the current load channel, and obtain the actual power deviation according to the actual power and the demand control instruction; and adjust the output power of the current load channel according to the actual power deviation. By obtaining the power supply demand of the current load and adjusting the power of the load channel based on the actual power deviation, the time from the change of the power supply demand to the completion of the power allocation is shortened, making the power allocation more flexible.

[0004] In this prior art, when the total power input of the load channel is less than the power demand of the load channel, the power compensation device will be activated to compensate for the power input, and when the total power input of the load channel is greater than the power demand of the load channel, the energy storage device will store the electric energy. However, in the actual operation process, since the electric energy that can be stored by the energy storage device has an upper limit, when the part of the total power input that is greater than the power demand exceeds the energy storage upper limit of the energy storage power supply, this part of the electric energy can no longer be stored in the energy storage power supply, resulting in damage to the UAV power generation device.

[0005] There is also a power supply device for an aircraft engine multi-electric control system disclosed in Chinese patent document CN112736891B, which includes: a power generation unit for extracting electric power from the high-pressure rotor and the low-pressure rotor of the aircraft engine respectively; a hybrid energy storage unit for balancing the power between the electrical load and the power generation unit; an electric energy management and distribution unit, which is electrically connected to the power generation unit and the hybrid energy storage unit respectively, and is used to manage and distribute the electric power extracted by the power generation unit; a high-voltage DC bus and a low-voltage DC bus, which are both electrically connected to the electric energy management and distribution unit, and are used to supply power to the electrical load under the control of the electric energy management and distribution unit. The power supply device for an aircraft engine multi-electric control system provided by the present invention can meet the greatly increased power demand and reliable power supply demand of the electrical load in the aircraft engine multi-electric control system, achieve the optimal overall performance and efficiency of the power supply system, and ensure the stability and safety of the power supply system.

[0006] In the prior art, when the hybrid energy storage unit balances the power between the electrical load and the power generation unit, the supercapacitor of the hybrid energy storage unit is used to balance the instantaneous change of power in the power supply system, and the battery of the hybrid energy storage unit is used to balance the relatively slow power change. However, since the balancing ability of the hybrid energy storage unit is limited by the ability of the supercapacitor and the battery, when the power output of the power generation unit is too large, the power generation unit will also be damaged.

[0007] There is also a Chinese patent document CN105529746B that discloses a flexible power distribution system, including a generator set and a first load group and a second load group powered by the generator set, the flexible power distribution system also includes an AC / DC module and an energy storage module configured for each load in the second load group; the flexible power distribution system also includes a control module, which is used to control the AC / DC module and the energy storage module in the second load group to jointly power the load when it is judged that the total output power of the generator set reaches a preset power, so as to control the total output power of the generator set not to be higher than the rated power; and when it is judged that the total output power of the generator set is lower than the preset power, increase the input power of the second load group, control the AC / DC module to power the corresponding load and store energy in the energy storage module. The present invention realizes the low-capacity configuration of the generator set and improves the utilization rate of the generator set. Similarly, in the prior art, due to the upper limit of the energy storage module that can be stored, the part of the electric energy that exceeds the upper limit of the energy storage module will also cause the problem of damage to the generator set. Summary of the invention

[0008] In order to solve the technical problem that the power generation unit is easily damaged in the prior art, the present invention provides an aviation UAV power distribution system, including a power generation unit, a power distribution control unit, an energy storage unit and an electrical load; the output power of the power generation unit follows the power demand of the electrical load, and the energy storage unit balances the power difference between the power demand of the electrical load and the output power of the power generation unit; wherein: the electrical load includes a passive load and an active load, and the power distribution control unit controls the opening or closing of the active load according to the power difference.

[0009] In the prior art, since the output power of the power generation unit will change with the power demand of the power load, when the power load is large, the output power of the power generation unit will also be relatively large. When the power demand of the power load drops suddenly, the power generation unit responds to the power demand of the power load with a lag, and when the power demand suddenly changes, the power difference will also be relatively large. Once this power difference exceeds the range that the energy storage unit can bear, either the existing power of the energy storage unit cannot make up for the shortfall of the current power demand of the power load, which will cause insufficient power supply to the power load and the power load cannot be used normally, or the power that can be charged into the energy storage unit is lower than the excess of the current output power of the current power generation unit, and the power generation unit will run away, resulting in the fracture and damage of key components such as the piston, connecting rod, crankshaft, and the power generation unit will be damaged.

[0010] Based on the above situation, the power load of the aerial drone was analyzed and it was found that in fact, during the operation of the aerial drone, the power load can be divided into two categories. One category includes passive loads such as radar loads and DCDC loads, and these loads are uncontrollable consumption loads, and the other category includes the remaining controllable consumption loads. Active loads. Therefore, in this solution, while using the energy storage unit to balance the power difference, the distribution control unit is also used to control the active load, and the active load is turned on or off to change the power demand of the power load, thereby changing the power difference between the power demand of the power load and the output power of the power generation unit, so that the power difference can match the balancing capacity of the energy storage unit, which can avoid the problem of the power load not being able to be used normally due to insufficient power supply and the power generation unit being damaged due to excessive power supply.

[0011] Preferably, when the power demand of the electrical load is greater than the output power of the power generation unit, the power distribution control unit controls the active load to be turned off, and when the output power of the power generation unit is greater than the power demand of the electrical load and the power difference is greater than the upper limit of the energy storage unit, the power distribution control unit controls the active load to be turned on. In this solution, when the power difference is greater than the upper limit of the energy storage unit, that is, the energy storage unit cannot continue to charge, the active load is turned on at this time, and the active load is used to consume the part of the electrical energy that exceeds the upper limit of the energy storage unit to avoid the engine from running away.

[0012] Preferably, when the power demand of the electrical load is greater than the output power of the power generation unit, the power distribution control unit controls the energy storage unit to discharge, and when the output power of the power generation unit meets the power demand of the electrical load, the energy storage unit starts to charge. In this solution, when the power demand of the electrical load is met, the energy storage unit is also charged to avoid power shortage of the energy storage unit, and it can be ensured that the energy storage unit can be discharged normally during subsequent use, so as to ensure that the power demand of the electrical load can be met in time when the power demand suddenly increases.

[0013] Preferably, when the output power of the power generation unit changes with the power demand of the power load, the power distribution control unit increases or decreases the output current according to a preset calibration slope. In this solution, the output power of the power generation unit can be stably adjusted by increasing or decreasing the output current according to the calibration slope, so as to avoid the power generation unit torque being too large or too small to affect the normal use of the power generation unit.

[0014] Preferably, when the output power of the power generation unit matches the power demand of the changed power load and the voltage of the energy storage unit reaches the preset target voltage, the energy storage unit stops charging and the power generation unit maintains the current speed to generate electricity. This solution can prevent the energy storage unit from being overcharged.

[0015] Preferably, when the passive load is not working and the voltage of the energy storage unit is low, the power generation unit charges the energy storage unit; when the voltage of the energy storage unit is close to the upper limit of energy storage, the power distribution control unit controls the active load to turn on, and the power generation unit supplies power to the energy storage unit and the active load at the same time; when the voltage of the energy storage unit reaches the upper limit of energy storage, the power generation unit supplies power to the active load and maintains the current speed on standby for power generation.

[0016] In this solution, when the passive load is not working, the power generation unit is used to charge the energy storage unit to avoid power shortage in the energy storage unit, and the active load is turned on according to the energy storage situation of the energy storage unit. The active load is used to consume the electric energy provided by the power generation unit, which can also avoid the engine from running out of control.

[0017] Preferably, the power generation unit adjusts the charging current based on the voltage closed loop during the power generation process, and the charging current change rate is set within the power response speed of the power generation unit. This solution can avoid the engine from running out of control.

[0018] Preferably, the energy storage unit is provided with a heating film. Since the temperature of the energy storage unit may be too low when the drone is flying at high altitudes, it is affected by the ambient temperature. Once the temperature of the energy storage unit is too low, it will affect the normal use and life of the energy storage unit. Therefore, in this solution, after the energy storage unit is provided with a heating film, the temperature of the energy storage unit can be controlled within a reasonable temperature range by heating the energy storage unit with the heating film to ensure the normal use of the energy storage unit.

[0019] In a second aspect, the present invention also provides a power supply pod including the above-mentioned aviation UAV power distribution system.

[0020] The present invention has the following beneficial effects:

[0021] 1. During the power switching process of the power load, the present invention can provide power instantly when the power demand increases suddenly to ensure the stability of the power load operation; when the power demand drops suddenly, it can absorb power instantly to prevent the power generation unit from running away, thereby ensuring the normal use of the power load and the power generation unit.

[0022] 2. The present invention can control the temperature of the energy storage unit within a reasonable temperature range, ensuring the normal use of the energy storage unit, thereby achieving long-term stable operation of the power distribution system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a module block diagram of a power distribution system in an embodiment of an aviation UAV power distribution system and a power supply pod of the present invention;

[0024] Figure 2 A schematic diagram of the energy flow when the power generation unit generates electricity;

[0025] Figure 3 This is a schematic diagram of energy flow when the passive load is not working①;

[0026] Figure 4 Schematic diagram of energy flow when the passive load is not working②;

[0027] Figure 5 It is a schematic diagram of energy flow when the passive load is not working and the energy storage unit is not charged;

[0028] Figure 6 Schematic diagram of energy flow when the power demand of passive load increases suddenly①;

[0029] Figure 7 Schematic diagram of energy flow when the power demand of passive load increases suddenly②;

[0030] Figure 8 Schematic diagram of energy flow when the power demand of passive load increases suddenly③. DETAILED DESCRIPTION

[0031] The following is further described in detail through specific implementation methods:

[0032] 1. Definition

[0033] Energy storage upper limit: refers to the upper limit of the amount of electricity that can be charged into the energy storage unit. When the energy storage unit reaches the upper limit, the energy storage unit cannot be charged with more electricity.

[0034] Calibration slope: refers to the current increase rate corresponding to the maximum fluctuation that the power generation unit can tolerate. The slope is obtained through testing.

[0035] Voltage closed-loop regulation: refers to controlling the current in the motor winding by adjusting the output voltage of the drive circuit, thereby controlling the motor's speed and torque output.

[0036] 2. The embodiment is basically as shown in the attached Figure 1 Shown: An aviation UAV power distribution system includes a power generation unit, a power distribution control unit, an energy storage unit and a power load.

[0037] The power unit includes an engine and a generator. After power is turned on, the power distribution control unit sends a start enable signal, the energy storage unit supplies power to the generator, the generator starts and drags the engine to start, and after the engine starts, it enters the power generation state, such as Figure 2 shown.

[0038] The output power of the power generation unit changes with the power demand of the power load. When the output power of the power generation unit changes with the power demand of the power load, the power distribution control unit increases or decreases the output current according to the preset calibration slope. The energy storage unit balances the power difference between the power demand of the power load and the output power of the power generation unit. When the power demand of the power load is greater than the output power of the power generation unit, the energy storage unit is in a discharging state and supplies power to the power load. When the power demand of the power load is less than the output power of the power generation unit, the energy storage unit is in a charging state and the power generation unit charges the energy storage unit.

[0039] The power load includes passive load and active load, and the power distribution control unit controls the opening or closing of the active load according to the power difference. The passive load refers to the uncontrollable consumption load, and the active load refers to the controllable consumption load. In this embodiment, the passive load takes the radar load as an example, and the active load takes the standby load as an example.

[0040] When the passive load is not working and the voltage of the energy storage unit is low, the power generation unit charges the energy storage unit; when the voltage of the energy storage unit is close to the upper limit of energy storage, the power distribution control unit controls the active load to turn on, and the power generation unit supplies power to the energy storage unit and the active load at the same time; when the voltage of the energy storage unit reaches the upper limit of energy storage, the power generation unit supplies power to the active load and maintains the current speed on standby for power generation.

[0041] When the passive load is working, when the power demand of the electrical load is greater than the output power of the power generation unit, the distribution control unit controls the energy storage unit to discharge, and the active load is turned off at the same time; when the output power of the power generation unit is greater than the power demand of the electrical load and the power difference is greater than the energy storage upper limit of the energy storage unit, the distribution control unit controls the active load to turn on; when the output power of the power generation unit meets the power demand of the electrical load, the energy storage unit starts to charge.

[0042] When the output power of the power generation unit matches the power demand of the changed power load and the voltage of the energy storage unit reaches the preset target voltage, the energy storage unit stops charging and the power generation unit maintains the current speed to generate electricity.

[0043] The energy storage unit is provided with a PTC heating film. In this embodiment, the energy storage unit is a battery pack, and when the temperature of the battery cell of the energy storage unit is lower than a calibrated threshold, the PTC heating film heats the battery cell.

[0044] This embodiment also discloses a power supply pod including the above-mentioned aviation drone power distribution system. The power distribution control unit includes VCU, ECU and PMU, wherein VCU is a pod controller, ECU is an engine controller, PMU is a power management unit, energy storage unit is a battery pack, BMS, i.e., power management system, is provided, active load is standby load, and passive load is radar load.

[0045] The specific implementation process is as follows: 1. Power generation unit generates electricity: After the power distribution system of the aviation UAV is powered on, the power distribution control unit sends a start enable signal, the energy storage unit supplies power to the generator, the generator starts and drags the engine to start, and after the engine starts, the power generation unit enters the power generation state.

[0046] 2. Passive load does not work: After the power generation unit is in power generation state, if the passive load does not work, the power generation unit charges the energy storage unit. The charging process is as follows: ① The power of the energy storage unit is lower than the preset power threshold. The power generation unit increases the power to the energy storage unit at a certain slope based on the voltage loop regulation. At the same time, the power distribution control unit controls the engine to increase to the target speed in a certain step length, such as Figure 3 ② During the charging process, the power of the energy storage unit gradually increases. When the power of the energy storage unit is close to the upper limit of the energy storage, the power generation unit reduces the power to charge the energy storage unit at a certain slope based on the voltage loop regulation. At the same time, the power distribution control unit controls the active load to turn on. The energy flow is as follows: Figure 4 ③ When the energy storage unit reaches the upper limit of the energy storage, the energy storage unit does not charge or discharge, the power distribution control unit controls the active load to continue to turn on, the power generation unit is on standby at the current speed, and the output power of the power generation unit is consumed by the active load to achieve stability when the passive load is not working. The energy flow is as follows Figure 5 shown.

[0047] 3. Passive load operation: After the power generation unit is in the power generation state, if the passive load is working, ① when the power demand of the passive load increases suddenly, the output voltage of the power generation unit drops and the energy storage unit discharges. Taking the radar load as an example of the passive load, before the radar load is normal, the voltage of the energy storage unit is 270V, and the power generation unit stably outputs 270V directly to the radar. When the radar load increases from 2kW to 10kW instantaneously, the voltage of the power generation unit shows a downward trend, and the energy storage unit generates power passively. If the active load is turned on at this time, the active load is controlled to be quickly turned off, such as Figure 6 As shown. At the same time, the current of the power generation unit rises according to the calibrated slope, and the rising slope matches the change rate that the engine can stably adjust, so that the torque at the generator shaft end can be slowly increased and controlled, and the engine can be prevented from stalling due to excessive torque at the shaft end. The rising slope is obtained through testing. The test standard is the current increase rate corresponding to the maximum fluctuation that the engine can tolerate. The current limit is also set to the maximum to ensure that the output response capability is maximized under the condition of stable engine output.

[0048] After the radar suddenly increases, it continues to run at 10kW. The voltage stabilizing characteristics of the power generation unit will gradually increase the output current, increase the torque at the engine shaft end, and the engine will follow the power based on the target speed closed loop. As the generator output power increases, the energy storage unit output power decreases until the power generation unit charges the energy storage unit to the upper limit of the energy storage unit. The power generation unit stops charging the energy storage unit and the power generation unit outputs 10kW directly for the radar.

[0049] In the above process, since the energy storage unit discharges preferentially when the power demand of the passive load suddenly increases, the power of the energy storage unit decreases and the voltage drops. The power generation unit continues to charge the energy storage unit based on the voltage loop regulation until the power of the energy storage unit reaches the energy storage upper limit.

[0050] To avoid engine stalling, the control strategy adopted is: after the engine is successfully started, when the engine speed is close to the stalling speed, the power distribution control unit gradually reduces the current, and the closed loop reduces the output torque at the motor shaft end to avoid the engine speed being lower than the stalling speed, causing abnormal engine stalling.

[0051] ② When the power demand of the passive load drops suddenly, the output voltage of the power generation unit rises and the energy storage unit is charged. Taking the radar load as an example, before the radar load is normal, the voltage of the energy storage unit is 270V. When the radar load drops from 10kW to 0kW instantly, the voltage of the power generation unit rises and the energy storage unit is charged. Figure 7 At the same time, the power generation unit decreases according to the calibrated slope, and the decreasing slope matches the stable and adjustable change rate of the engine power, so as to realize the controllable slow decrease of the torque at the generator shaft end and avoid the engine torque load throwing and running. At this time, if the energy storage unit reaches the upper limit of energy storage, the active load is controlled to open quickly, such as Figure 8The descending slope is obtained through testing, and the test standard is the current increase rate corresponding to the maximum fluctuation that the engine can tolerate.

[0052] In the above process, the power generation unit supplies power to the passive load and the energy storage unit respectively. When the power demand of the passive load drops suddenly, if the power drop difference is less than or equal to the rechargeable power of the energy storage unit, the energy storage unit absorbs the excess output power of the power generation unit. If the power drop difference is greater than the rechargeable power of the energy storage unit, the active load is turned on, and the active load and the energy storage unit consume the excess output power of the power generation unit. The power drop difference refers to the power value of the sudden drop in the power demand of the passive load, and the rechargeable power of the energy storage unit is the difference between the energy storage upper limit of the energy storage unit and the current power of the energy storage unit.

[0053] If the radar suddenly increases by 10kW, then suddenly drops to 0kW, and then suddenly increases to 10kW again, the radar will increase and decrease suddenly at the millisecond level, and the engine power response characteristics will be lagging. However, the energy storage unit, as an energy pool, acts as a carrier for rapid energy release and rapid energy absorption, and can fully meet the radar's instantaneous power supply needs. Since the power generation unit always follows the trend of replenishing the energy storage unit to the target voltage, the energy storage unit will give priority to meeting the radar's power supply needs during the entire process, and the power generation unit will follow to replenish the energy storage unit's electricity to prevent the energy storage unit from running out of power.

[0054] After utilizing the power distribution system in this embodiment, the required power of the passive load is switched multiple times, and the switching time under different states is shown in Table 1.

[0055] Table 1

[0056] Power variation Keep Time Switching time 2.5~4.5kW Reach the second level 25ms 2.5~7.5kW ≮40ms 40ms 5~7.5kW Reach the second level 25ms 5~10kW ≮25ms 25ms 7.5~10.5kW ≮15ms 15ms

[0057] It can be concluded from Table 1 that the power distribution system in the present invention has the demand for transient power switching, and the transient power switching can reach the millisecond level. In addition, while using the energy storage unit to balance the power difference, the power distribution control unit is also used to control the active load, and the required power of the power load is changed by turning the active load on or off, thereby changing the power difference between the required power of the power load and the output power of the power generation unit, so that the power difference can match the balancing ability of the energy storage unit, and thus can avoid the problem that the power load cannot be used normally due to insufficient power supply and the power generation unit is damaged due to excessive power supply.

[0058] The above is only an embodiment of the present invention. The common sense such as the known specific structure and characteristics in the scheme is not described in detail here. The ordinary technicians in the relevant field know all the common technical knowledge in the technical field of the invention before the application date or priority date, can obtain all the existing technologies in the field, and have the ability to apply the conventional experimental means before that date. The ordinary technicians in the relevant field can improve and implement this scheme in combination with their own abilities under the enlightenment given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the relevant field to implement this application. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can be made, which should also be regarded as the protection scope of the present invention, which will not affect the effect of the implementation of the present invention and the practicality of the patent. The protection scope required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. An aviation UAV power distribution system, comprising a power generation unit, a power distribution control unit, an energy storage unit and an electrical load; the output power of the power generation unit follows the power demand of the electrical load, and the energy storage unit balances the power difference between the power demand of the electrical load and the output power of the power generation unit; characterized in that: The power load includes a passive load and an active load, and the power distribution control unit controls the turning on or off of the active load according to the power difference.

2. The power distribution system for an aerial drone according to claim 1, characterized in that: When the power demand of the electrical load is greater than the output power of the power generation unit, the power distribution control unit controls the active load to turn off; when the output power of the power generation unit is greater than the power demand of the electrical load and the power difference is greater than the energy storage upper limit of the energy storage unit, the power distribution control unit controls the active load to turn on.

3. The power distribution system for an aerial drone according to claim 2, characterized in that: When the power demand of the electrical load is greater than the output power of the power generation unit, the power distribution control unit controls the energy storage unit to discharge, and when the output power of the power generation unit meets the power demand of the electrical load, the energy storage unit starts to charge.

4. The power distribution system for an unmanned aerial vehicle according to any one of claims 1 to 3, characterized in that: When the output power of the power generation unit changes with the required power of the power load, the power distribution control unit increases or decreases the output current according to a preset calibration slope.

5. The power distribution system for an aerial drone according to claim 4, characterized in that: When the output power of the power generation unit matches the required power of the changed power load and the voltage of the energy storage unit reaches the upper limit of energy storage, the energy storage unit stops charging and the power generation unit maintains the current speed to generate electricity.

6. The power distribution system for an aerial drone according to claim 5, characterized in that: When the passive load is not working and the voltage of the energy storage unit is low, the power generation unit charges the energy storage unit; when the voltage of the energy storage unit is close to the energy storage upper limit, the power distribution control unit controls the active load to turn on, and the power generation unit supplies power to the energy storage unit and the active load at the same time; when the voltage of the energy storage unit reaches the energy storage upper limit, the power generation unit supplies power to the active load and maintains the current speed for standby power generation.

7. The power distribution system for an aerial drone according to claim 6, characterized in that: The power generation unit adjusts the charging current based on the voltage closed loop during the power generation process, and the charging current change rate is set within the power response speed of the power generation unit.

8. The power distribution system for an aerial drone according to claim 7, characterized in that: The energy storage unit is provided with a heating film.

9. A power supply pod, characterized in that: Comprising an aviation UAV power distribution system as described in any one of claims 1-8.

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