Power supply system for the on-board spacecraft complex (RUB 160.00). Power supply for spacecraft Primary power supply systems for spacecraft
Rostec
JSC "Concern "Radioelectronic Technologies"
KRET has developed a new type of batteries for operation in space
The development of competitive space technology requires a transition to new types of batteries that meet the requirements of advanced power supply systems. spacecraft.
Nowadays, spacecraft are used to organize communication systems, navigation, television, study weather conditions and natural resources
Earth, exploration and exploration of deep space.
One of the main conditions for such devices is accurate orientation in space and correction of motion parameters. This significantly increases the requirements for the device’s power supply system. The problems of power supply of spacecraft, and, first of all, developments to identify new sources of electricity, are of paramount importance at the global level.
Currently, the main sources of electricity for spacecraft are solar and rechargeable batteries.
Solar panels have reached their physical limits in terms of their performance. Their further improvement is possible using new materials, in particular gallium arsenide. This will allow you to increase the power of the solar battery by 2-3 times or reduce its size.
Among the rechargeable batteries for spacecraft today, nickel-hydrogen batteries are widely used. However, the energy-mass characteristics of these batteries have reached their maximum (70-80 Wh/kg). Their further improvement is very limited and, in addition, requires large financial costs.
In this regard, there is currently an active introduction of lithium-ion batteries (LIB) into the space technology market.
The characteristics of lithium-ion batteries are much higher compared to other types of batteries with a similar service life and number of charge-discharge cycles. The specific energy of lithium-ion batteries can reach 130 Wh/kg or more, and the energy efficiency is 95%.
An important fact is that LIBs of the same size can operate safely when connected in parallel in groups, thus it is easy to form lithium-ion batteries of different capacities.
One of the main differences between LIBs and nickel-hydrogen batteries is the presence of electronic automation units that monitor and manage the charge-discharge process. They are also responsible for leveling the voltage imbalance of individual LIBs, and ensure the collection and preparation of telemetric information about the main parameters of the battery.
But still, the main advantage of lithium-ion batteries is considered to be weight reduction compared to traditional batteries. According to experts, the use of lithium-ion batteries on telecommunications satellites with a power of 15-20 kW will reduce the weight of batteries by 300 kg. Considering that the cost of putting 1 kg of useful mass into orbit is about 30 thousand dollars, this will significantly reduce financial costs.
One of the leading Russian developers of such batteries for spacecraft is OJSC Aviation Electronics and Communication Systems (AVEX), part of KRET. The technological process of manufacturing lithium-ion batteries at the enterprise ensures high reliability and reduced costs.
Owners of patent RU 2598862:
Usage: in the field of electrical engineering for power supply of spacecraft from primary sources of different power. The technical result is increased reliability of power supply. The power supply system of the spacecraft contains: a group of solar batteries of direct sunlight (1), a group of solar batteries of reflected sunlight (7), a generating circuit (8), a voltage stabilizer (2), a charger (3), a discharge device (4), battery (5), rectifier device (9), battery charge controller (10) and consumers (6). The alternating voltage from the generating circuit (8) is converted into constant voltage in the block (9) and is supplied to the first input of the battery charge controller (10). Constant voltage from solar panels of reflected sunlight (7) is supplied to the second input of the battery charge controller (10). The total voltage from the generating circuit and solar panels of reflected sunlight from the first output of the controller (10) enters the second input of the battery (5). From the second output of the controller to the first input of the battery (5), control signals are received from switches (15-21) having contacts 1-3, and switches (22-25) having contacts 1-2. The number of controlled switching devices depends on the number of batteries in the battery. To recharge the selected battery (11-14) on the corresponding switches, their first contacts open with the third and close with the second, on the corresponding switches the first and second contacts close. The corresponding battery connected in this way to the second input of the battery is recharged with the rated charging current until a command is received from the controller (10) to change the next battery. The consumer (6) receives power from the remaining batteries, bypassing the disconnected one, from the first battery output (5). 5 ill.
The invention relates to space technology and can be used as part of rotation-stabilized spacecraft.
A known power supply system for a spacecraft with common buses (analog), which contains solar panels(primary energy source), battery, consumers. The disadvantage of this system is that the voltage in this system is unstabilized. This leads to energy losses in cable networks and in built-in individual consumer stabilizers.
A known power supply system for a spacecraft with separated buses and parallel connection of a voltage stabilizer (analog), which contains a charger, a discharge device, and a battery. Its disadvantage is the impossibility of using an extreme power regulator for solar panels.
The closest in technical essence to the proposed system is a spacecraft power supply system with separated buses and with a series-parallel connection of a voltage stabilizer 2 (prototype), which also contains solar panels of direct sunlight 1, a charger 3, a discharge device 4, a rechargeable battery 5 (Fig. 1). The disadvantage of this power supply system is the inability to receive, convert and accumulate electrical energy from sources of different power, such as the energy of the Earth's magnetic field and the energy of reflected sunlight from the Earth's surface.
The purpose of the invention is to expand the capabilities of the spacecraft power supply system to receive, convert and accumulate electricity from various primary sources of different power, which allows increasing the active life and power supply of spacecraft.
In fig. 2 shows the power supply system of a rotation-stabilized spacecraft; FIG. 3 - battery containing switching devices controlled by the controller; in fig. 4 - appearance rotation-stabilized spacecraft in FIG. Figure 5 schematically shows one of the options for the motion of a rotation-stabilized spacecraft in orbit.
The power supply system of a rotation-stabilized spacecraft contains a group of solar panels 7, designed to convert sunlight reflected from the Earth into electrical energy, generating a circuit 8, which is a set of conductors (winding) located along the body of the spacecraft, in which an electromotive force is induced for counting the rotation of the spacecraft around its axis in the Earth's magnetic field, a rectifier device 9, a battery charge controller from power sources of different power 10, a battery 5 containing controller-controlled switching devices 15-25 that connect or disconnect individual batteries 11-14 to controller 9 to recharge them with low current (Fig. 2).
The system operates as follows. During the process of launching the spacecraft into orbit, it is rotated in such a way that the axis of rotation of the apparatus and the solar panels of direct sunlight are oriented towards the Sun (Fig. 4). During the movement of a rotating spacecraft in orbit, the generating circuit intercepts the induction lines of the Earth's magnetic field at the speed of rotation of the spacecraft around its axis. As a result, according to the law of electromagnetic induction, an electromotive force is induced in the generating circuit
where µ o is the magnetic constant, H is the strength of the Earth's magnetic field, S in is the area of the generating circuit, N c is the number of turns in the circuit, ω is the angular frequency of rotation.
When the generating circuit is closed to the load, current flows in the consumer-generating circuit circuit. The power of the generating circuit depends on the torque of the spacecraft around its axis
where J KA is the moment of inertia of the spacecraft.
Thus, the generating circuit is an additional source of electricity on board the spacecraft.
The alternating voltage from the generating circuit 8 is rectified on block 9 and supplied to the first input of the battery charge controller 10. The direct voltage from the solar panels of reflected sunlight 7 is supplied to the second input of the battery charge controller 10. The total voltage from the first output of the controller 10 goes to the second input of the battery 5. From the second output of the controller to the first input of the battery 5, control signals are received from switches 15-21, having contacts 1-3, and switches 22-25, having contacts 1-2. The number of controlled switching devices depends on the number of batteries in the battery. To recharge the selected battery (11-14) on the corresponding switches, their first contacts open with the third and close with the second, on the corresponding switches the first and second contacts close. The corresponding battery connected in this way to the second input of the battery is recharged with a low current until a command is received from the controller 10 to change the next battery. The consumer receives power from the remaining batteries, bypassing battery 5, which is disconnected from the first output.
When the spacecraft is in orbit in position 1 (Fig. 4, 5), the solar panels of reflected sunlight are oriented towards the Earth. At this moment, the charger 3 included in the power supply system of the spacecraft receives electricity from solar panels of direct sunlight 1, and the battery charge controller 10 receives electricity from solar panels of reflected sunlight 7 and the generating circuit 8. In the position of the spacecraft 2, solar panels of direct solar The lights 1 remain directed towards the Sun, while the solar cells of the reflected sunlight are partially obscured. At this moment, the charger 3 of the spacecraft power supply system continues to receive electricity from solar panels of direct sunlight, and the controller 10 loses part of the energy from block 7, but continues to receive energy from block 8 through the rectifier 9. In the position of the spacecraft 3, all groups of solar panels are shaded, charger 3 does not receive electricity from solar panels 1, and on-board consumers of the spacecraft receive electricity from the battery. The battery charge controller continues to receive energy from the generating circuit 8, recharging the next battery. At the position of the spacecraft 4, the solar panels of direct sunlight 1 are again illuminated by the Sun, while the solar panels of reflected sunlight are partially obscured. At this moment, the charger 3 of the spacecraft power supply system continues to receive electricity from solar panels of direct sunlight, and the controller 10 loses some of the energy from block 7, but continues to receive energy from block 8 through the rectifier 9.
Thus, the power supply system of a rotation-stabilized spacecraft is capable of receiving, converting and accumulating: a) energy of direct and reflected from sunlight; b) kinetic energy of rotation of the spacecraft in the Earth's magnetic field. Otherwise, the functioning of the proposed system is similar to the known one.
The technical result - increasing the active life and power supply of the spacecraft - is achieved through the use of a microcontroller charger as part of the spacecraft's power supply system, which makes it possible to charge the battery from electrical energy sources of different powers (reflected sunlight and energy from the Earth's magnetic field).
The practical implementation of the functional units of the present invention can be performed as follows.
A three-phase two-layer winding with an insulated copper wire can be used as a generating circuit, which will bring the shape of the electromotive force curve closer to a sinusoid. A bridge circuit of a three-phase rectifier with low-power diodes of type D2 and D9 can be used as a rectifier, which will reduce the ripple of the rectified voltage. The MAX 17710 microcontroller can be used as a battery charge controller. It can work with unstable sources with an output power range from 1 μW to 100 mW. The device has a built-in boost converter for charging batteries from sources with a typical output voltage of 0.75 V and a built-in regulator to protect batteries from overcharging. Lithium-ion batteries with a battery voltage equalization subsystem (balancing system) can be used as a battery containing controller-controlled switching devices. It can be implemented based on the MSP430F1232 controller.
Thus, the distinctive features of the proposed device contribute to achieving this goal.
Sources of information
1. Analog world Maxim. New microcircuits / Symmetron Group of Companies // Issue No. 2, 2013. - 68 p.
2. Grilikhes V.A. Solar energy and space flights / V.A. Griliches, P.P. Orlov, L.B. Popov - M.: Nauka, 1984. - 211 p.
3. Kargu D.L. Power supply systems for spacecraft / D.L. Kargu, G.B. Steganov [and others] - St. Petersburg: VKA im. A.F. Mozhaisky, 2013. - 116 p.
4. Katsman M.M. Electrical machines / M.M. Katzman. - textbook manual for special students technical schools. - 2nd ed., revised. and additional - M.: Higher. Shk., 1990. - 463 p.
5. Pryanishnikov V.A. Electronics. Course of lectures / V.A. Pryanishnikov - St. Petersburg: Krona Print LLC, 1998. - 400 p.
6. Rykovanov A.N. Li-ion battery power systems / A.N. Rykovanov // Power Electronics. - 2009. - No. 1.
7. Chilin Yu.N. Modeling and optimization in spacecraft power systems / Yu.N. Chilin. - St. Petersburg: VIKA, 1995. - 277 p.
A spacecraft power supply system containing a group of solar batteries of direct sunlight, a charger that receives electricity from solar batteries of direct sunlight, a discharge device that powers consumers from a battery, a voltage stabilizer that powers consumers from a solar battery of direct sunlight, characterized in that additionally contains a group of solar panels designed to convert sunlight reflected from the Earth into electrical energy, a generating circuit, which is a set of conductors (winding) located on the body of the spacecraft, in which an electromotive force is induced due to the rotation of the spacecraft around its axis in a magnetic field the Earth field, a rectifier device, and also contains a battery charge controller from power sources of different power, a battery, which additionally contains switching devices controlled by the controller that connect or disconnect individual batteries to the controller to recharge them.
Similar patents:
The invention relates to space technology and can be used to provide power supply to spacecraft (SV) and stations. The technical result is the use of a thermal control system to obtain additional energy.
The invention relates to the field of electrical engineering. An autonomous power supply system contains a solar battery, an electricity storage device, a charger-discharge device and a load consisting of one or more voltage stabilizers with end consumers of electricity connected to their outputs.
The invention relates to the electrical industry and can be used in the design of autonomous power supply systems artificial satellites Earth (satellite). The technical result is an increase in the specific energy characteristics and reliability of the autonomous power supply system of the satellite. A method is proposed for powering a load with direct current in an autonomous power supply system for an artificial Earth satellite from a solar battery and a set of secondary sources of electricity - rechargeable batteries containing Nacc batteries connected in series, which consists of stabilizing the voltage on the load, charging and discharging the batteries through individual chargers and discharge converters, while the discharge converters are made without voltage booster units, for which the number of batteries Nacc in each battery is selected from the ratio: Nacc≥(Un+1)/Uacc.min, where Nacc is the number of batteries in the series circuit of each battery; Un - voltage at the output of the autonomous power supply system, V; Uacc.min is the minimum discharge voltage of one battery, V, the charging converters are made without voltage booster units, for which the voltage at the operating point of the solar battery is selected from the ratio: Urt>Uacc.max Nacc+1, where Urt is the voltage at the operating point of the solar battery at the end of the guaranteed resource of its work, B; Uacc.max is the maximum charging voltage of one battery, V, while the calculated number of batteries Nacc is additionally increased based on the ratio: Nacc≥(Un+1)/Uacc.min+Nfailure, where Nfailure is the number of permissible battery failures, and voltage stabilization by load and battery charging is carried out using extreme voltage regulation of the solar panel.
The invention relates to the field of electrical engineering. The technical result consists in expanding the operational capabilities of the system, increasing its load power and ensuring maximum uninterrupted operation while maintaining optimal parameters battery operation when powering consumers with direct current.
The invention relates to the field of solar energy, in particular to solar installations that continuously monitor the Sun, both with solar radiation concentrators and with flat silicon modules, designed to power consumers, for example, in areas of unreliable and decentralized power supply.
The invention relates to the electrical industry and can be used in the design of autonomous power supply systems for artificial Earth satellites (AES).
The invention relates to solar array rotation systems (SPSB) of a spacecraft (SC). The invention is intended to accommodate SPSB elements for rotating a high-power solar battery and transmitting electricity from the solar battery to the spacecraft.
The invention relates to the field of solar energy conversion and its transmission to ground consumers. The space power station contains a solar collector (1) of a lobe type, a station housing (2) and a bundle (3) of microwave antennas. The collector (1) is made of plates (panels) of photoelectric converters - both main and auxiliary. The plates have a rectangular and triangular shape. Their connections are made in the form of automatic hooks and loops, which, when the collector is deployed, are connected through a multi-leaf mechanism. When folded, the collector (1) has the shape of a cube. The beam antennas (3) focus microwave energy onto an amplifier, which transmits this energy to ground-based power plants. The technical result of the invention is aimed at increasing the efficiency of energy conversion and transmission to consumers over vast areas of the Earth. 16 ill.
Usage: in the field of electrical engineering for power supply of spacecraft from primary sources of different power. The technical result is increased reliability of power supply. The power supply system of the spacecraft contains: a group of solar batteries of direct sunlight, a group of solar batteries of reflected sunlight, a generating circuit, a voltage stabilizer, a charger, a discharge device, a rechargeable battery, a rectifier device, a battery charge controller and consumers. The alternating voltage from the generating circuit is converted into constant voltage in the unit and is supplied to the first input of the battery charge controller. The constant voltage from the solar panels of reflected sunlight is supplied to the second input of the battery charge controller. The total voltage from the generating circuit and solar panels of reflected sunlight from the first output of the controller goes to the second input of the battery. From the second output of the controller to the first input of the battery, control signals are received from switches having contacts 1-3 and switches having contacts 1-2. The number of controlled switching devices depends on the number of batteries in the battery. To recharge the selected battery, on the corresponding switches their first contacts are opened with the third and closed with the second, on the corresponding switches the first and second contacts are closed. The corresponding battery connected in this way to the second input of the battery is recharged with the rated charging current until a command is received from the controller to change the next battery. The consumer receives power from the remaining batteries, bypassing the disconnected one, from the first battery output. 5 ill.
SOURCES OF ELECTRICAL ENERGY FOR SPACE VEHICLES
prof. Lukyanenko Mikhail Vasilievich
head Department of Automatic Control Systems of the Siberian State Aerospace University named after Academician M.F. Reshetnyova
The study and exploration of outer space requires the development and creation of spacecraft for various purposes. Currently, automatic unmanned spacecraft for the formation of global system communications, television, navigation and geodesy, information transmission, studying weather conditions and natural resources of the Earth, as well as deep space exploration. To create them, it is necessary to ensure very stringent requirements for the accuracy of the orientation of the device in space and the correction of orbital parameters, and this requires increasing the power supply of spacecraft.
One of the most important onboard systems of any spacecraft, which primarily determines its performance characteristics, reliability, service life and economic efficiency, is the power supply system. Therefore, the problems of development, research and creation of power supply systems for spacecraft are of paramount importance, and their solution will allow reaching the world level in terms of specific mass indicators and active life.
Over the last decade, the world's leading companies have made a push to increase the power supply of spacecraft, which allows, with the same restrictions on the mass of the devices imposed by existing carriers, to continuously increase the power of the payload. Such achievements were made possible thanks to the efforts made by the developers of all components of on-board power supply systems, and above all, power sources.
The main sources of electricity for spacecraft currently are solar and rechargeable batteries.
Solar batteries with silicon monocrystalline photovoltaic converters have reached their physical limit in terms of mass-specific characteristics. Further progress in the development of solar cells is possible with the use of photovoltaic converters based on new materials, in particular, gallium arsenide. Three-stage photovoltaic converters made of gallium arsenide are already used on the US platform HS-702, on the European Spasebus-400, etc., which has more than doubled the power of the solar battery. Despite the higher cost of photovoltaic converters made from gallium arsenide, their use will make it possible to increase the power of a solar battery by 2-3 times or, at the same power, to correspondingly reduce the area of a solar battery compared to silicon photovoltaic converters.
Under geostationary orbit conditions, the use of photoelectric converters based on gallium arsenide makes it possible to provide a specific power of a solar battery of 302 W/m2 at the beginning of operation and 230 W/m2 at the end of its active life (10-15 years).
The development of four-stage photovoltaic converters from gallium arsenide with an efficiency of about 40% will make it possible to have a solar cell power density of up to 460 W/m2 at the beginning of operation and 370 W/m2 at the end of its active life. In the near future, we should expect a significant improvement in the mass-specific characteristics of solar batteries.
Currently, batteries based on the nickel-hydrogen electrochemical system are widely used on spacecraft; however, the energy-mass characteristics of these batteries have reached their limit (70-80 Wh/kg). The possibility of further improving the specific characteristics of nickel-hydrogen batteries is very limited and requires large financial costs.
To create competitive space technology, it was necessary to switch to new types of electrochemical power sources suitable for use as part of the power supply system for promising spacecraft.
The space technology market is currently actively introducing lithium-ion batteries. This is due to the fact that lithium ion batteries have a higher specific energy compared to nickel-hydrogen batteries.
The main advantage of the lithium-ion battery is the reduction in weight due to the higher energy-to-mass ratio. The energy-weight ratio of lithium-ion batteries is higher (125 Wh/kg) compared to the maximum achieved for nickel-hydrogen batteries (80 Wh/kg).
The main advantages of lithium-ion batteries are:
- reduction in battery weight due to a higher energy-to-weight ratio (weight reduction for the battery is ~40%);
- low heat generation and high energy efficiency (charge-discharge cycle) with very low self-discharge, which ensures the simplest control during launch, transfer orbit and normal operation;
- a more technologically advanced manufacturing process for lithium-ion batteries compared to nickel-hydrogen batteries, which allows for good repeatability of characteristics, high reliability and reduced costs.
According to experts from SAFT (France), the use of lithium-ion batteries on telecommunications satellites with a power of 15-20 kW will reduce the mass of batteries by 300 kg (the cost of putting 1 kg of useful mass into orbit is ~$30,000).
Main characteristics of the VES140 lithium-ion battery (developed by SAFT): guaranteed capacity 39 A*h, average voltage 3.6 V, end-of-charge voltage 4.1 V, energy 140 Wh, specific energy 126 Wh/kg , weight 1.11 kg, height 250 mm and diameter 54 mm. The VES140 battery is qualified for space applications.
In Russia, today OJSC Saturn (Krasnodar) has developed and manufactured the lithium-ion battery LIGP-120. Main characteristics of the LIGP-120 battery: nominal capacity 120 Ah, average voltage 3.64 V, specific energy 160 Wh/kg, weight 2.95 kg, height 260 mm, width 104.6 mm and depth 44.1 mm. The battery has a prismatic shape, which provides significant advantages in terms of specific volumetric energy of the battery compared to SAFT batteries. By varying the geometric dimensions of the electrode, you can obtain a battery of different capacities. This design provides the highest specific-volume characteristics of the battery and allows the battery to be configured to ensure optimal thermal conditions.
Modern systems power supplies for spacecraft are a complex complex of power sources, converting and distribution devices, integrated into an automatic control system and designed to power on-board loads. Secondary power supplies are an energy-converting complex consisting of a certain number of identical pulse voltage converters operating for a common load. In the traditional version, classical converters with a rectangular shape of the current and voltage of the key element and control via pulse width modulation are used as pulse voltage converters.
To improve the technical and economic indicators of the spacecraft power supply system, such as power density, efficiency, speed, electromagnetic compatibility, we proposed the use of quasi-resonant voltage converters. Studies were carried out on the operating modes of two parallel-connected quasi-resonant serial-type voltage converters with switching of an electronic switch at zero current values and a pulse-frequency control law. Based on the results of modeling and studying the characteristics of prototypes of quasi-resonant voltage converters, the advantages of this type of converters were confirmed.
The results obtained allow us to conclude that the proposed quasi-resonant voltage converters will find wide application in power supply systems for digital and telecommunication systems, instrumentation, process equipment, automation and telemechanics systems, security systems, etc.
Current problems are the study of the functioning features of space power sources, the development of their mathematical models and the study of energy and dynamic regimes.
For these purposes, we have developed and manufactured unique equipment for studying power supply systems of spacecraft, which allows automated testing of on-board power sources (solar and rechargeable batteries) and power supply systems in general.
In addition, an automated workstation for studying the energy-thermal conditions of lithium-ion batteries and battery modules and a hardware complex for studying the energy and dynamic characteristics of gallium arsenide solar cells were developed and manufactured.
An important aspect of the work is also the creation and research of alternative sources of electricity for spacecraft. We have conducted research on a flywheel energy storage device, which is a super flywheel combined with electric machine. A flywheel rotating in a vacuum on magnetic supports has an efficiency of 100%. The two-rotor flywheel energy storage device has a property that makes it possible to realize a triaxial angular orientation. In this case, the power gyroscope (gyrodine), as an independent separate subsystem, can be excluded, i.e. The flywheel energy storage device combines the functions of an energy storage device and a power gyroscope.
Research has been carried out on electrodynamic tether systems as a source of electricity for a spacecraft. To date, a mathematical model of an electrodynamic cable system has been developed to calculate maximum power; the dependences of energy characteristics on orbital parameters and tether length were determined; a methodology has been developed for determining the parameters of a cable system that ensures the generation of a given power; the orbital parameters (altitude and inclination) at which the most efficient use of tether systems in energy generation mode is achieved are determined; The capabilities of the cable system when operating in traction mode were investigated.
EURASIAN NATIONAL UNIVERSITY
Them. L.N. Gumilyov
Faculty of Physics and Technology
Department of Space Engineering and Technology
REPORT
BY PRODUCTION
PRACTICE
ASTANA 2016
Introduction………………………………………………………………………………...........3
1 General information on the power supply of spacecraft.……………....4
1.1 Primary sources of electricity……………………………4
1.2 Automation of the power supply system.................................................... ….5
2 Solar space power plants…………..…………………..…......6
2.1 Solar batteries operating principle and design………….….....6
3 Electrochemical space power plants…………………………..12
3.1 Chemical current sources……………………………………...13
3.2 Silver-zinc batteries…………………....15
3.3 Nickel-cadmium batteries………………………16
3.4 Nickel-hydrogen batteries……………………..17
4 Selection of parameters of solar panels and buffer storage.........18
4.1 Calculation of buffer storage parameters…………………………18
4.2 Calculation of parameters of solar panels……………………………..20
Conclusion………………………………………………………………………………….23
List of sources used………………………………………………………...24
Specifications...………………………………………………………………………………25
INTRODUCTION
One of the most important onboard systems of any spacecraft, which primarily determines its performance characteristics, reliability, service life and economic efficiency, is the power supply system. Therefore, the problems of development, research and creation of power supply systems for spacecraft are of paramount importance.
Automation of flight control processes of any spacecraft (SC) is unthinkable without electrical energy. Electrical energy is used to drive all elements of spacecraft devices and equipment (propulsion group, controls, communication systems, instrumentation, heating, etc.).
In general, the power supply system generates energy, converts and regulates it, stores it for periods of peak demand or shadow operation, and distributes it throughout the spacecraft. The power supply subsystem may also convert and regulate voltage or provide a range of voltage levels. It frequently turns equipment on and off and, to increase reliability, protects against short circuit and isolates faults. The design of the subsystem is affected by cosmic radiation, which causes degradation of solar panels. The life of a chemical battery often limits the life of a spacecraft.
Current problems are the study of the functioning features of space power sources. The study and exploration of outer space requires the development and creation of spacecraft for various purposes. Currently, automatic unmanned spacecraft are the most widely used for the formation of a global system of communications, television, navigation and geodesy, information transfer, studying weather conditions and natural resources of the Earth, as well as deep space exploration. To create them, it is necessary to ensure very stringent requirements for the accuracy of the orientation of the device in space and the correction of orbital parameters, and this requires increasing the power supply of spacecraft.
General information about the power supply of spacecraft.
The geometry of spacecraft, design, mass, and active life are largely determined by the power supply system of spacecraft. Power supply system or otherwise referred to as power supply system (PSS) spacecraft - the spacecraft system that provides power to other systems is one of the most important systems. Failure of the power supply system leads to failure of the entire device.
The power supply system usually includes: a primary and secondary source of electricity, transformers, chargers and automatic control.
1.1 Primary energy sources
Various energy generators are used as primary sources:
Solar panels;
Chemical current sources:
Batteries;
Galvanic cells;
Fuel cells;
Radioisotope energy sources;
Nuclear reactors.
The primary source includes not only the electricity generator itself, but also the systems that serve it, for example, the solar panel orientation system.
Often energy sources are combined, for example, a solar battery with a chemical battery.
Fuel cells
Fuel cells have high weight and size characteristics and power density compared to a pair of solar batteries and a chemical battery, are resistant to overloads, have a stable voltage, and are silent. However, they require a supply of fuel, so they are used on devices with a period of stay in space from several days to 1-2 months.
Hydrogen-oxygen fuel cells are mainly used, since hydrogen provides the highest calorific value, and, in addition, the water formed as a result of the reaction can be used on manned spacecraft. To ensure normal operation of fuel cells, it is necessary to ensure the removal of water and heat generated as a result of the reaction. Another limiting factor is the relatively high cost of liquid hydrogen and oxygen and the difficulty of storing them.
Radioisotope energy sources
Radioisotope energy sources are used mainly in the following cases:
High flight duration;
Missions to the outer regions of the Solar System, where the flux of solar radiation is low;
Reconnaissance satellites with side-scan radar cannot use solar panels due to low orbits, but have a high energy requirement.
1.2 Automation of the power supply system
It includes devices for controlling the operation of the power plant, as well as monitoring its parameters. Typical tasks are: maintaining system parameters within specified ranges: voltage, temperature, pressure, switching operating modes, for example, switching to a backup power source; failure recognition, emergency protection of power supplies, in particular by current; delivery of information about the state of the system for telemetry and to the astronaut console. In some cases, it is possible to switch from automatic to manual control either from the astronaut's console or by commands from the ground control center.
Related information.
Illustration copyright SPL
Space missions lasting several decades - or even longer - will require a new generation of power sources. The columnist decided to figure out what options designers have.
The power system is a vital component of a spacecraft. These systems must be extremely reliable and designed to operate under harsh conditions.
Modern complex devices require more and more energy - what does the future of their power sources look like?
The average modern smartphone can barely last a day on a single charge. And the Voyager probe, launched 38 years ago, is still transmitting signals to Earth, having already left the solar system.
Voyager's computers are capable of performing 81 thousand operations per second - but the smartphone processor works seven thousand times faster.
- Other articles on the BBC Future website in Russian
When designing a phone, of course, it is assumed that it will be regularly recharged and is unlikely to be several million kilometers from the nearest outlet.
It will not be possible to charge the battery of a spacecraft, which, according to the plan, should be located a hundred million kilometers from the current source - it needs to be able to either carry on board batteries of sufficient capacity to operate for decades, or generate electricity on its own.
It turns out that solving such a design problem is quite difficult.
Some on-board devices only need electricity occasionally, but others need to be running all the time.
Receivers and transmitters must always be turned on, and in manned or manned flight space station- also life support and lighting systems.
Illustration copyright NASA Image caption The Voyager engines are not the most modern, but they have successfully served for 38 yearsDr. Rao Surampudi heads the Energy Technologies Program at the Jet Propulsion Laboratory at the California Institute of Technology in the United States. For more than 30 years, he has been developing power supply systems for various NASA vehicles.
The power system typically accounts for about 30% of a spacecraft's total mass, he said. It solves three main problems:
- power generation
- electricity storage
- electricity distribution
All of these parts of the system are vital to the operation of the device. They must weigh little, be durable and have a high “energy density” - that is, produce a lot of energy from a fairly small volume.
In addition, they must be reliable, since sending a person into space to repair breakdowns is very impractical.
The system must not only generate enough energy for all needs, but also do so throughout the entire flight - which could last for decades, and in the future, perhaps centuries.
“The design life must be long - if something breaks, there will be no one to fix it,” says Surampudi. “A flight to Jupiter takes from five to seven years, to Pluto - more than 10 years, and to leave the solar system, it takes from 20 up to 30 years old."
Illustration copyright NASA Image caption NASA's asteroid deflection mission will use a new type of solar power that is more efficient and durable than its predecessorsThe energy systems of a spacecraft are in very specific conditions - they must remain operational in the absence of gravity, in a vacuum, under the influence of very intense radiation (which would disable most conventional electronic devices) and extreme temperatures.
“If you land on Venus, the temperature outside will be 460 degrees,” says the specialist. “And when landing on Jupiter, the temperature will be minus 150.”
Vehicles heading towards the center of the solar system have no shortage of energy collected by their photovoltaic panels.
These panels may look a little different from solar panels installed on the roofs of residential buildings, but they operate with much higher efficiency.
It is very hot near the Sun and photovoltaic panels can overheat. To avoid this, the panels are turned away from the Sun.
In planetary orbit, photovoltaic panels are less efficient: they produce less energy, since from time to time they are fenced off from the Sun by the planet itself. In such situations, a reliable energy storage system is necessary.
Atomic solution
Such a system can be built on the basis of nickel-hydrogen batteries that can withstand more than 50 thousand charging cycles and operate for more than 15 years.
Unlike regular batteries, which don't work in space, these batteries are sealed and can function normally in a vacuum.
As you move away from the Sun, the level of solar radiation naturally decreases: for Earth it is 1374 watts per square meter, for Jupiter - 50, and for Pluto - only one watt per square meter.
Therefore, if the device flies beyond the orbit of Jupiter, then it uses atomic power systems.
The most common of these is the radioisotope thermoelectric generator (RTG), used on the Voyager, Cassini and Curiosity rover probes.
Illustration copyright NASA Image caption An improved radioisotope Stirling generator is being considered as a possible power source for long-duration missions.These power supplies have no moving parts. They produce energy from the decay of radioactive isotopes such as plutonium. Their service life exceeds 30 years.
If RTGs cannot be used (for example, if a shield that is too massive for flight is needed to protect the crew from radiation), and photovoltaic panels are not suitable because the distance from the Sun is too great, then fuel cells can be used.
Hydrogen-oxygen fuel cells were used in the American space programs Gemini and Apollo. Such cells cannot be recharged, but they release a lot of energy, and the byproduct of this process is water, which the crew can then drink.
NASA and the Jet Propulsion Laboratory are working to create more powerful, energy-intensive and compact systems with a high operating life.
But new spacecraft need more and more energy: their onboard systems are constantly becoming more complex and consume a lot of electricity.
For long flights, atomic-electric propulsion may be used
This is especially true for ships that use an electric drive - for example, ion propulsion, first used on the Deep Space 1 probe in 1998 and since then widely adopted.
Electric engines typically operate by electrically releasing fuel at high speed, but there are also those that accelerate the vehicle through electrodynamic interaction with the magnetic fields of the planets.
Most earthly energy systems are not capable of operating in space. Therefore, any new circuit undergoes a series of serious tests before being installed on a spacecraft.
NASA laboratories recreate the harsh conditions in which the new device will have to function: it is irradiated with radiation and subjected to extreme temperature changes.
Towards new frontiers
It is possible that future flights will use improved radioisotope Stirling generators. They work on a similar principle to RTGs, but are much more efficient.
In addition, they can be made very small in size - although this makes the design further complicated.
New batteries are also being created for NASA's planned flight to Europa, one of Jupiter's moons. They will be able to operate at temperatures from -80 to -100 degrees.
And the new lithium-ion batteries that designers are currently working on will have twice the capacity of the current ones. With their help, astronauts will be able, for example, to spend twice as much time on the lunar surface before returning to the ship to recharge.
Illustration copyright SPL Image caption To provide energy to such settlements, new types of fuel will most likely be required.New solar panels are also being designed that could effectively collect energy in conditions of low light and low temperatures - this will allow devices on photovoltaic panels to fly further from the Sun.
At some stage, NASA intends to establish a permanent base on Mars - and perhaps on more distant planets.
The energy systems of such settlements must be much more powerful than those currently used in space, and designed for much longer operation.
The Moon has a lot of helium-3 - this isotope is rare on Earth and is an ideal fuel for fusion power plants. However, it has not yet been possible to achieve sufficient stability of thermonuclear fusion in order to use this energy source in spacecraft.
In addition, the thermonuclear reactors that exist today occupy the space of an airplane hangar, and in this form it is impossible to use them for space flights.
Is it possible to use conventional nuclear reactors - especially in vehicles with electric propulsion and in planned missions to the Moon and Mars?
In this case, the colony will not have to maintain a separate source of electricity - the ship’s reactor can play its role.
For long flights, atomic-electric propulsion may be used.
"The Asteroid Deflection Mission apparatus needs large solar panels so that it has enough electrical energy to maneuver around the asteroid, says Surampudi. “We are currently considering solar-electric propulsion, but nuclear-electric propulsion would be cheaper.”
However, we are unlikely to see nuclear-powered spacecraft anytime soon.
“This technology is not yet sufficiently mature. We must be absolutely sure of its safety before launching such a device into space,” explains the specialist.
Further rigorous testing is needed to ensure the reactor can withstand the rigors of spaceflight.
All of these advanced energy systems will allow spacecraft to operate longer and fly longer distances - but they are still in the early stages of development.
Once the tests are successfully completed, such systems will become a mandatory component of flights to Mars - and beyond.
- You can read it on the website.
