GB/T 44821.3-2026General technical requirements for stratospheric airships - Part 3: Energy system (English PDF)

4.1 Composition

An energy system should consist of the following parts.

a) Power generation equipment. typically composed of solar cell arrays;

b) Energy storage devices. typically consisting of energy storage battery packs and emergency power supplies;

c) Power conversion equipment. typically composed of power converters;

d) Power distribution equipment. typically consists of power distribution equipment;

e) Power control equipment. typically consists of devices such as maximum power point tracking controllers and energy managers.

4.2 Functions

The energy system should have the following functions.

a) Power generation. Converting solar energy into electrical energy;

b) Energy storage. Storing electrical energy in energy storage battery packs and emergency power supplies;

c) Power conversion. Converting the primary electrical energy generated by the solar array into the form of electrical energy required by downstream electrical equipment;

d) Power distribution. distributing electrical energy to electrical equipment;

e) Power management and control. managing and controlling the operating mode of the energy system and monitoring the status of the energy system.

4.3 Performance

4.3.1 Solar Cell Array

Solar cell modules and solar cell arrays should meet the following requirements.

a) The conversion efficiency of the solar cell module is not less than 21%;

b) The power-to-weight ratio of the solar cell module shall not be less than 370 W/kg;

c) The total daily power generation of the solar array meets the energy balance requirements of the energy system, measured in watt-hours (Wh).

Note. a) and b) refer to the condition of zero atmospheric mass (AM0).

4.3.2 Energy Storage Battery Pack

Energy storage battery packs should meet the following requirements.

a) The energy density of the energy storage battery pack shall not be less than 260Wh/kg;

b) The energy storage battery pack meets the energy balance requirements of the energy system, and the unit is watt-hour (Wh).

4.3.3 Emergency Power Supply

Emergency power supplies should meet the following requirements.

a) The energy density of the emergency power supply shall not be less than 260Wh/kg;

b) The emergency power supply meets the power supply needs of electrical equipment during the specified emergency operating time in an emergency, and the unit is watt-hours.

(Wh).

4.3.4 Output Power

The output power of the energy system should meet the maximum power consumption of the airship's electrical equipment, measured in watts (W).

4.3.5 Power Converter

The power converter should meet the following requirements.

a) The output power of the power converter meets the total power of the downstream electrical equipment, in watts (W);

b) The conversion efficiency of the power converter shall not be less than 94%.

Note. b) refers to the rated output power condition.

4.3.6 Power Distribution Channel

The rated operating current of each power distribution channel of the power distribution equipment shall not be less than the rated operating current of the downstream power equipment, in amperes (A).

4.3.7 Steady-state voltage

The steady-state voltage of the energy system bus should be compatible with the power supply voltage of the downstream electrical equipment, and the unit is volt (V).

4.3.8 Ripple Voltage

The peak-to-peak value of the bus ripple voltage of the energy system should not exceed 1% of the rated output voltage.

4.3.9 Voltage transients

When the downstream load power jumps from 50% to 100% and from 100% to 50%, the bus voltage change of the energy system should meet the following requirements.

The regulations require.

4.3.10 Energy Balance

Under specified flight dates, locations, and altitudes, the energy system should be able to achieve energy balance and day-night cycle.

4.4 Interface

4.4.1 Mechanical Interface

Mechanical interfaces mainly include the mounting interfaces between equipment such as solar cell modules installed on the capsule and the airship capsule, as well as the interfaces between internal equipment and the equipment bay.

The mechanical interfaces, such as the installation interfaces for connecting cables to the casing and equipment compartment, should meet the following requirements.

a) The mounting interfaces of equipment such as solar cell modules mounted on the capsule are compatible with the corresponding mounting interfaces on the capsule;

b) The installation interfaces between the equipment inside the cabin and the equipment compartment meet the geometric dimensional requirements of the equipment inside the cabin;

c) The installation interfaces of the connecting cables to the casing and equipment compartment comply with the specifications of the specific model.

4.4.2 Electrical Interface

The electrical interface mainly includes the power supply interface and data communication interface between the energy system and other systems of the airship. The electrical interface should meet the following requirements.

Require.

a) Use standard and general-purpose interfaces;

b) The power supply interface's voltage, current, and other specifications are compatible with the electrical equipment;

c) The type, transmission rate, data format, and communication protocol of the communication interface are compatible with the corresponding system;

d) It has measures to prevent incorrect insertion.

4.4.3 Thermal Interface

Thermal interfaces primarily include the heat exchange interfaces between the energy system and the environmental control system. The thermal interfaces should meet the requirements of the energy system equipment within the airship.

There are requirements for ambient temperature during normal operation under certain working conditions.

4.5 Weight

The weight of the energy system should meet the overall weight distribution requirements of the airship.

4.6 Appearance

The appearance of all equipment in the energy system should be free from scratches, dents, cracks, contamination, and other mechanical damage.

4.7 Environmental adaptability

4.7.1 Natural Environment

The energy system should be able to adapt to the environmental conditions experienced by the stratospheric airship during its mission, including atmospheric temperature, atmospheric pressure, and solar radiation.

The following environmental requirements should be included.

a) The normal operating atmospheric pressure range is typically 5 kPa to 103 kPa.

b) Temperature environment requirements.

1) Equipment located outside the environmental control chamber typically operates within a temperature range of -90°C to 65°C;

2) The equipment inside the environmental control chamber meets the temperature requirements of the chamber.

c) Solar radiation environment with a radiation intensity of 1361 W/m2 under AM0 conditions for external equipment on the pod.

4.7.2 Mechanical Environment

The energy system should be able to withstand all mechanical environmental conditions, such as vibration, shock, and acceleration, during storage, transportation, ground testing, and flight envelope.

The test items should include vibration, shock, road transportation, etc.

4.7.3 Electromagnetic Environment

The energy system and its equipment should be able to adapt to the electromagnetic environment of the airship under all operating conditions, including the energy system itself and other onboard equipment.

The systems should be compatible with each other.

Energy systems and equipment should undergo electromagnetic compatibility testing in accordance with general requirements and relevant standards. Test items typically include power line conduction.

Emission testing, electric field radiated emission testing, cable bundle injected conduction susceptibility testing, electric field radiated susceptibility testing, electrostatic discharge susceptibility testing

Projects such as...

4.8 Reliability

The reliability of the energy system should meet the following requirements.

a) The reliability indicators of the energy system (such as reliability or mean time between failures) meet the overall requirements allocated to the airship;

b) The energy system has redundancy.

4.9 Security

The security of energy systems should meet the following requirements.

a) It can isolate the fault when the energy system is damaged or experiences a partial failure;

b) The maximum power point tracking controller has overheat and current limiting protection functions;

c) The energy storage battery pack and emergency power supply have overcurrent, short circuit, overheat, overcharge, and over-discharge protection functions, and safety measures should be implemented when necessary.

test;

d) The power converter has protection functions against short circuit, overcurrent, overvoltage, and overheating;

e) The power distribution equipment has overload and short circuit protection functions, and should be protected and isolated in case of faults in the power equipment or power distribution lines.

5.1 Test Items

The energy system should undergo the following tests.

a) Suitability check;

b) Functional testing;

c) Performance testing;

d) Interface inspection;

e) Weight check;

f) Visual inspection;

g) Environmental testing;

h) Reliability testing;

i) Safety testing.

5.2 Test Methods

5.2.1 Completeness check

The components of the energy system are inventoried, and those that meet the requirements of 4.1 are deemed qualified.

5.2.2 Functional Testing

The output of the solar array is simulated using a solar cell array simulator, and the power of the airship's electrical equipment is simulated using a simulated load. A host computer is used for this simulation.

The aircraft simulates the ship's onboard computer, and by setting up a solar array simulator, simulated loads, and energy storage battery packs, it enables the energy system to operate in different modes.

Next, test whether the energy system functions properly. Conduct the test according to Figure 1, with the specific steps as follows.

a) Adjust the solar array simulator to output the values under maximum daytime sunlight conditions, and adjust the load to match the airship's average daytime usage.

Electrical power. The energy storage battery pack is set to an incompletely charged state. At this time, the energy system operates at the maximum power output of the solar array, supplying...

Load power supply and charging mode for energy storage battery pack;

b) When the energy storage battery pack is basically fully charged, adjust the solar array simulator so that its output matches the output under maximum daytime sunlight conditions.

The load is adjusted to the airship's average daytime power consumption, at which point the energy system automatically switches to the solar array power-limited output mode.

In this configuration, the solar cell array supplies power to the load and float-charges the energy storage battery pack;

c) Adjust the solar array simulator to output the light conditions during sunrise or sunset, and adjust the load to fly.

The submarine's average daytime power consumption is [a certain value]. At this time, the solar array's power generation cannot meet the load demand, and the energy system automatically switches to [a different type of solar power].

In the mode where the solar cell array and the energy storage battery pack jointly supply power to the load, the energy storage battery pack supplements the load's power demand by discharging.

need;

d) Turn off the solar array simulator output to simulate nighttime conditions. In this state, the solar array does not generate electricity, and the energy system automatically switches to storage.

Battery pack discharges to supply power to the load;

e) Turn off the output of the solar array simulator and energy storage battery pack to simulate emergency operation. The energy system will automatically switch to emergency operation.

In this mode, emergency power supplies provide power to critical loads.

Figure 1 Schematic diagram of the test principle

The energy system can switch normally between different operating modes, and each device operates normally in different operating modes, which can be monitored by a host computer.

If the energy system is in good condition, it is deemed to have passed the functional test.

5.2.3 Performance Test

5.2.3.1 Solar Cell Array

The test was conducted using a method simulating the stratospheric lighting environment in which the airship is located. The specific steps are as follows.

a) Set the light intensity, duration, and angle of the light simulation device;

b) Test the output power of the solar cell array;

c) Continuously record the output power and time of the solar array;

d) Calculate the total daily power generation according to formula (1).

5.2.3.2 Energy Storage Battery Pack

The specific testing method is as follows.

a) At (20±5)°C, the discharge power is set to the total average power of the airship's electrical equipment, and the fully charged battery is discharged to the specified level.

Voltage.

b) Record the battery discharge power and time.

c) Calculate the cumulative discharge energy using the integral method according to formula (2).

d) Measure the weight of the battery.

e) Calculate the battery energy density according to formula (3).

5.2.3.3 Emergency Power Supply

The specific testing method is as follows.

a) At (20±5)°C, the discharge power is set to the total average power of the airship's emergency electrical equipment, and the fully charged battery is discharged...

Powered to the specified voltage;

b) Record the battery discharge power and time;

c) Calculate the cumulative discharge energy using the integral method according to formula (2);

d) Measure the weight of the battery;

e) Calculate the battery energy density according to formula (3);

f) At -70°C or the specified low temperature, supply emergency power to the ship's electrical equipment in emergency situations (or simulate emergency situations).

Power supply to the following electrical loads;

g) Test and record continuous working time under emergency conditions.

The emergency power supply's energy and energy density both meet the specified requirements; the equipment operates normally under emergency power supply conditions, and the emergency operating time meets the specified requirements.

5.2.3.4 Output Power

The output of the solar array is simulated using a solar cell array simulator, and the power of the airship's electrical equipment is simulated using a simulated load, as shown in Figure 1.

The specific testing methods are as follows.

a) Set the simulated load to the maximum total power of the airship's electrical equipment, and enable it by setting up the solar array simulator and energy storage battery pack.

The power source system operates in solar array power mode;

b) Measure the output power of the system;

c) By setting up a solar array simulator and energy storage battery pack, the energy system can operate in a mode where the energy storage battery pack provides power independently;

d) Measure the output power of the system.

If the output power of the energy system meets the maximum total power requirement of the electrical equipment under different operating modes, it is considered qualified.

5.2.3.6 Power Distribution Channel

The specific testing method is as follows.

a) The input terminals of the power distribution equipment are connected to the test power supply, and the output terminals of each power distribution channel are connected to the simulated load;

b) Adjust the output voltage of the test power supply to the rated value of the input voltage of the power distribution equipment, and adjust the output terminals of each power distribution channel to simulate the negative voltage.

The load is the rated operating current of the power distribution channel;

c) Each power distribution channel of the power distribution equipment should be able to work normally, and the rated operating current of each power distribution channel of the power distribution equipment should be measured and recorded.

If the rated operating current of each power distribution channel of the power distribution equipment is not less than the rated operating current of the downstream power equipment, it is considered qualified.

5.2.3.7 Steady-state voltage

The energy system was tested in conjunction with energy balance and cycle tests to determine the steady-state voltage of the energy system bus over one cycle.

If the steady-state voltage of the busbar meets the specified requirements, it is deemed qualified.

5.2.3.8 Ripple Voltage

The output of the solar array is simulated using a solar cell array simulator, and the power of the airship's electrical equipment is simulated using a simulated load, as shown in Figure 1.

The exhibition test, and the specific test method are as follows.

a) Set the maximum total power of the simulated load and simulate the airship's electrical equipment by setting up a solar array simulator and an energy storage battery pack.

The energy system operates in solar array power mode;

b) Measure the ripple voltage of the power system bus using an oscilloscope.

If the bus ripple voltage of the energy system meets the requirements of 4.3.8, it is considered qualified.

5.2.3.9 Voltage transients

The output of the solar array is simulated using a solar cell array simulator, and the power of the airship's electrical equipment is simulated using a simulated load, as shown in Figure 1.

The test was conducted, and the specific test methods are as follows.

a) By setting up a solar array simulator, simulated load, and energy storage battery pack, the energy system can operate under solar array power supply.

model;

b) Change the load from 50% to 100% and from 100% to 50%;

c) Measure the change in bus voltage of the energy system during load transitions;

d) By setting up a solar array simulator, simulated load, and energy storage battery pack, the energy system can operate separately on the energy storage battery pack.

Power supply mode;

e) Jumping the load from 50% to 100% and from 100% to 50%;

f) Measure the change in bus voltage of the energy system during load jumps.

5.2.3.10 Energy Balance

The test was conducted according to Figure 1, using a solar array simulator to simulate the output of a solar array under normal stratospheric conditions over a 24-hour period.

The variation in power consumption of the airship's electrical equipment was simulated using a simulated load over a 24-hour period, simulating the energy system's operation in the stratosphere.

The power supply situation in an environment over a 24-hour period; if the energy system can achieve energy balance and diurnal cycle within a 24-hour period, it is considered to be...

qualified.

5.2.4 Interface Inspection

5.2.4.1 Mechanical Interface

The mechanical interface dimensions of each piece of equipment are measured using measuring instruments. If they meet the requirements of 4.4.1, the equipment is deemed qualified.

5.2.4.2 Electrical Interface

Electrical interface inspection is carried out along with functional and performance tests; if the requirements of 4.4.2 are met, the interface is deemed qualified.

5.2.4.3 Thermal Interface

Thermal interface inspection is carried out during energy system environmental testing, and is deemed qualified if it meets the requirements of 4.4.3.

5.2.5 Weight Check

The energy system equipment is weighed using measuring instruments. If the weight of the energy system equipment and the total weight of the energy system meet the specified requirements, it is considered to be...

qualified.

5.2.6 Visual Inspection

The appearance of the energy system equipment is visually inspected, and if it meets the requirements of 4.6, it is deemed qualified.

5.2.7 Environmental Testing

5.2.7.1 Natural and mechanical environment

The natural and mechanical environment test methods for energy systems shall be carried out in accordance with the requirements of GB/T 2423 (all parts), when all test items

If the requirements are met, it is deemed qualified.

5.2.7.2 Electromagnetic Environment

The specific testing method is as follows.

a) After the energy system is integrated, conduct electromagnetic compatibility testing on the energy system according to the test items specified in the overall requirements;

b) Powering the airship's electrical equipment and systems using an energy system in a ground environment (or in conjunction with the entire system after the airship's final assembly).

(The joint ground test was conducted.) The energy system and other systems of the airship are all working normally and do not interfere with each other.

If all the above test items meet the requirements, the test is deemed qualified.

5.2.8 Reliability Testing

Reliability tests shall be conducted in accordance with the methods specified in GB/T 5080 (all parts), and the test shall be deemed qualified if the requirements of 4.8 are met.

5.2.9 Safety Test

The safety testing methods are as follows.

a) Review the fault protection function and safety test reports of each device;

b) Simulate a partial fault in the solar cell array, observe the operating status of the energy system, and ensure the energy system can issue alarms and that other parts of the solar cell array...

The pool array is functioning normally;

c) Simulate a scenario where the energy storage battery pack fails and has no output under illuminated conditions, observe the operating status of the energy system, and check if the energy system can issue an alarm and...

The solar array continues to provide power;

d) Simulate a scenario where the energy storage battery pack fails and has no output under no-light conditions, observe the operating status of the energy system, and check if the energy system can switch to emergency mode.

In power supply mode, emergency loads are powered by emergency power supply, and other devices are not powered.

e) In the event of a power conversion device failure, the energy system can automatically switch to emergency power supply, which will then power the critical loads.

f) Select a typical load channel and simulate a load short circuit. The load channel protection device should be able to perform the corresponding protection action. Other load channels...

It works normally.

If all the above test results are normal, the test is considered qualified.

6.1 Inspection Classification

The inspection categories specified in this document are as follows.

a) Identification and testing;

b) Quality consistency inspection.

6.2 Identification and Testing

6.2.1 Inspection Items

6.2.2 Acceptance Criteria

If all test items meet the requirements, the test is deemed qualified.

6.3 Quality Consistency Inspection

6.3.1 Inspection Items

The testing items shall be carried out in accordance with the provisions of Table 1.

6.3.2 Inspection Quantity

All were checked.

Note. Considering the small number of actual samples in the production of stratospheric airship energy systems, the quality consistency inspection will not be conducted by sampling inspection, but by full inspection.

6.3.3 Acceptance Criteria

If all inspection items meet the requirements, the inspection is deemed qualified.

7.1 Marking

The delivered energy system products should have nameplates, labels, or other markings. Products such as solar cell modules, which are difficult to label, should have labels on the packaging box.

Mark it.

7.2 Packaging

After cleaning and drying, energy system products should be neatly packed into dedicated packaging boxes according to the packing procedures and operating precautions.

Take good support, fixation, vibration damping, and moisture protection measures to prevent product damage during packing. In addition to the product itself, the packaging box should contain other items.

Technical documents such as certificates of conformity, instruction manuals, and packing lists.

7.3 Transportation and Storage

The energy system should meet the overall transportation requirements of the airship and be adaptable to road, rail, and air transport without being directly affected by extreme weather conditions.

Waterway and other transportation.

Energy system products should meet the overall storage requirements of the airship, and the performance of the energy system should meet the specified requirements within the specified storage period.