RU2293690C2 - Method of control of spacecraft power supply system - Google Patents

Abstract

FIELD: spacecraft onboard power supply systems.

SUBSTANCE: proposed method includes determination of charge-discharge characteristics of onboard power supply sources, transformation of energy of external power sources, maintenance of required state of charge of onboard power sources due to energy of external power sources and consumption of energy power requirements exceed transformed energy of external power sources. Intervals of flight time required for maintenance of probable and determined level of state of charge of onboard power sources are also determined. At probable level when power requirements exceed transformed energy of external power sources, amount of energy in onboard power source required for performing the program is determined. Then, intervals of time of charge and self-discharge of onboard power sources are determined; besides that, shift of beginning of charge of onboard power sources ensuring required amount of energy is determined. Required state of charge of onboard power sources is maintained at said intervals of their charge-discharge at control of power consumption in accordance with flight program. When energy transformed from external power sources exceed consumed power, onboard power source is charged and state of charge is maintained at charge-discharge intervals. Time intervals for maintenance of determined state of charge of onboard power sources when consumed power exceeds transformed power of external sources is predicted. Before beginning of these intervals, determined charge of onboard power sources is performed at said charge-discharge intervals. Then, power requirements of onboard power sources are regulated in accordance with flight program ensuring excess of discharge energy of onboard power sources by consumed energy. Upon completion of predicted interval, onboard power source is charged for subsequent maintenance of probable state of charge of onboard power sources. When necessary shift is made for above-indicated determined charge of onboard power sources after which probable and determined charge are alternated.

EFFECT: enhanced reliability of method due to enhanced use of onboard and external power sources.

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Description

The invention relates to the field of energy systems of spacecraft (SC) and methods for their control.

Known methods of power supply of spacecraft, implemented by energy systems, based on the work of primary energy sources (see [1], p.13-17).

External and onboard sources of various types of energy are used as primary sources. Each of the species is transformed directly or through intermediate species into electrical energy. The main type of external energy source is solar radiation, which is most often used in two forms: light and heat.

Electric energy onboard the spacecraft is generated either by transforming the energy of external sources, the reserves of which can be considered unlimited, or by transforming the energy stored in on-board sources, whose reserves are limited by the capabilities of the devices of storage devices and converters of different types of energy. In this case, the accumulation of on-board sources of energy received from external sources is not provided.

Thus, the power supply of the spacecraft should be provided in the first case due to the constant supply of energy from external sources or in the second case due to autonomous on-board energy devices (for example, based on radioisotope generators, (see [1], pp. 39-41) possessing the necessary energy reserves for a long-term flight program.

As is known, at present, the nominal existence of the overwhelming number of spacecraft in orbit is calculated over the years. In this case, the indicated approach to the spacecraft energy management method implemented by energy systems is not always acceptable mainly for two reasons. The first reason is that periodically the devices cannot receive energy from solar radiation. This is due both to the conditions of their flight (the presence of "shadow" sections of the orbit) and the possibility of losing orientation on the Sun of the main devices that transform the solar into electrical energy.

The second reason is that the creation and operation of powerful on-board alternative solar energy sources (primarily using nuclear energy) is fraught with a number of difficulties in the production, storage, transportation, preparation for launch, etc.

Therefore, for most spacecraft, preference is given to methods of energy supply management, implemented by energy systems, replenishing their reserves from external space sources of energy and primarily using the energy of solar radiation.

In these methods, on-board energy sources (BIE) periodically replenish their reserves due to the transformation of the energy of external sources. Further, the energy of the sources is transformed into electrical energy.

A typical example of energy systems that implement the spacecraft power management method is the power supply system presented in [2], on pages 189-195. The spacecraft energy management method using the presented system is taken as a prototype.

The prototype method contains a definition of the charge-discharge characteristics ix of the onboard energy sources of the spacecraft, where i = 1, 2, 3, ..., I is the number of BIE. As these sources are used electrochemical batteries. In this case, the values of the nominal upper Wv _i and lower Wn _i levels of charge of energy sources are determined. For the charge of airborne sources, as well as for the power supply of the spacecraft as a whole, the light form of solar radiation energy is used. The indicated energy is transformed (converted) in photovoltaic converters (PEC) of solar batteries (SB) into electrical energy.

The charge of onboard sources is based on the results of monitoring the measured values of the charge level of onboard sources We _i (t). At the same time, the charge level of the onboard sources is maintained within the acceptable ranges of [Wn _i , Wv _i ] due to the excess electricity on board the spacecraft transformed from light energy.

There is also constant monitoring of electricity consumption onboard the spacecraft during the flight program at current times t. And in case of excess of electric power consumption over its arrival, on-board energy sources are connected to the spacecraft cable network for energy consumption of on-board sources.

The main disadvantage of this method of controlling the power supply of the spacecraft is that the management of onboard energy sources is not planned both from the point of view of the sources themselves and their relevance for the flight program.

Each on-board energy source corresponds to a section of charge and self-discharge in the absence of an external load connected. The indicated charge-discharge cycles can be separated in time in such a way that at certain current moments of time t the charge of the on-board sources will be summed up either according to the maximum or minimum values. Most often, it will have an intermediate value between these extremes. How this charge is consistent with the implementation of the flight program in the prototype method is not specified. From the analysis of the prototype, it follows that part of the onboard power sources allocated to the emergency reserve can be used to power the onboard load after the discharge of the main onboard sources. However, in this case, no actions are provided for the maximum use of the main energy sources until the emergency reserve is activated. In essence, the connection of the specified backup source must be considered as an emergency on board the spacecraft. And, if you do not take into account the complete failure of the main onboard energy sources, then the violation of the indicated energy balance occurs only due to the ill-considered energy supply management of the spacecraft.

As a rule, in this case, the backup sources have a smaller resource in the number of charge-discharge cycles. Consequently, ill-considered use of them under the on-board load can reduce the spacecraft stay in orbit. This is especially true for manned transport ships.

In the present invention, the problem of increasing the reliability of power supply of the spacecraft due to the systematic management of energy resources embedded in the onboard energy sources of spacecraft accumulating the energy of external sources is solved. At the same time, this regularity takes into account the demand for on-board sources for the implementation of the flight program.

бортовых источников энергии, а также величины скоростей саморазряда бортовых источников энергии

по указанным измеренным значениям в пределах диапазона значений [Wn_i, Wv_i], определяют интервалы времени заряда (t_zi, t_ri) и саморазряда (t_ri, t_zi) i-x бортовых источников, где t_zi, t_ri - моменты времени начала заряда и начала разряда i-x бортовых источников энергии соответственно, определяют смещение начала заряда i-x бортовых источников Δt_i, обеспечивающее необходимое количество энергии бортовых источников Wa(t), и производят поддержание уровня заряженности бортовых источников с момента времени t_zi+Δt_i на интервалах (t_zi, t_ri) и (t_ri, t_zi) до выполнения условияTo achieve a technical result in a method for controlling the power supply of a spacecraft, comprising determining the charge-discharge characteristics ix of the onboard energy sources of the spacecraft, including the values of the nominal upper Wv _i and lower Wn _i charge levels of these energy sources, where i = 1, 2, 3 ,. .., I - the number of onboard energy sources, the transformation of the energy of external sources, the measurement of the charge levels ix of the onboard sources at current times t We _i (t), the maintenance of the charge level of the onboard sources accuracy within the acceptable ranges of values [Wn _i , Wv _i ] due to the transformation of energy from external sources, control of energy consumption on board the spacecraft during the flight program and the energy consumption of onboard sources when the energy consumed on board the spacecraft exceeds the transformed energy from external sources , additionally determine the flight time intervals to maintain probabilistic and deterministic levels of energy charge ix of on-board sources, in the case of The transition to maintaining the probabilistic charge level of the spacecraft’s onboard energy sources when the energy consumed exceeds the transformed energy from external sources determines the amount of energy in the onboard sources required to complete the spacecraft flight program Wa (t), equivalent to the amount of transformed electric energy, then on the program interval flight indicated maintaining the probabilistic charge level of onboard energy sources measure led charge rate ranks

on-board energy sources, as well as self-discharge rates of on-board energy sources

from the indicated measured values within the range of values [Wn _i , Wv _i ], determine the time intervals of the charge (t _zi , t _ri ) and self-discharge (t _ri , t _zi ) ix on-board sources, where t _zi , t _ri are the moments of the start time the charge and the onset of the discharge ix on-board energy sources, respectively, determine the displacement of the onset of the charge ix on-board sources Δt _i , which provides the necessary amount of energy on-board sources Wa (t), and maintain the charge level of the on-board sources from time t _zi + Δt _i at intervals (t _zi, t _ri) and (t _ri, t _zi) to perform yc Ovia

where We (t _zi ) ∈ [Wn _i , Wv _i ] is the value of the current charge i-ro of the on-board source of energy We _i (t) at time t _zi ,

and if the energy consumed on board the spacecraft exceeds that transformed from external sources over the interval of maintaining the probabilistic charge level, the energy consumption from ix on-board sources is regulated in accordance with the energy requirement for carrying out the spacecraft flight program and then, when the energy transformed from external sources exceeds the energy consumed on board the spacecraft, they produce a charge ix of on-board energy sources up to Wv _i and maintain their levels for distances at time intervals (t _zi , t _ri ) and (t _ri , t _zi ) from time t _zi + Δt _i until condition (1) is fulfilled, as well as during the execution of the spacecraft’s flight program, time intervals (t ₀ , t _k ) maintaining a determinate charge level of on-board energy sources at which the energy consumed exceeds the transformable from external sources, determine the value ΔW (t ₀ ) of the excess of the transformable energy consumed by the energy for the indicated intervals, determine the value of Wa (t _k ) at the end time interval (t ₀ , t _k ) and before the start of the predicted interval t ₀ produce a determinate charge of on-board sources in the intervals (t _zi , t _ri ) and (t _ri , t _zi ) from the time t _zi + Δt _i until the condition

further, in the process of executing the flight program, on the interval (t ₀ , t _k ), the energy consumption from ix on-board sources is regulated in accordance with the amount of energy required to execute the flight program of the spacecraft, while ensuring that the discharge energy received from on-board sources exceeds the energy consumed on board the spacecraft, and after the predicted end of the interval, starting from time t _{to produce} a charge ix board sources to obtain Wv _i values in order to maintain ve oyatnostnogo state of charge of said board sources to satisfy the condition (1) and as needed to pass the above deterministic charge onboard power sources to satisfy the condition (2), then alternated as aforesaid maintenance of probabilistic and deterministic charge levels ix onboard energy sources.

The technical result in the newly developed method of controlling the power supply of the spacecraft is aimed at the systematic use of the energy resources of the onboard energy sources of the spacecraft, taking into account their charge-discharge cycles and the demand for the flight program.

To explain the technical nature of the invention, 1 to 6 are introduced into the description.

Figure 1 presents graphs of the initial charge-discharge cyclograms of onboard sources of different types of energy.

Figure 2 presents a graph of the sum of the initial charge-discharge cyclograms of onboard sources of different types of energy, as well as a graph of the probabilistic level of charge of onboard sources of energy of the spacecraft.

Figure 3 presents graphs of the controlled charge-discharge cycles of on-board sources of different types of energy, providing the current probabilistic charge level of on-board sources of energy of the spacecraft.

Figure 4 presents a graph of the sum of the controlled charge-discharge cycles of on-board sources of different types of energy, providing the current probabilistic charge level of on-board sources of energy of the spacecraft.

Figure 5 presents graphs of the controlled charge-discharge cycles of on-board sources of different types of energy, providing a determinate level of charge on-board sources of energy of the spacecraft.

Figure 6 presents a graph of the sum of the controlled charge-discharge cycles of on-board sources of different types of energy, providing the current probabilistic and determinate levels of charge on-board sources of energy of the spacecraft.

Consider, for example, a large spacecraft of the class of orbital stations that has three types of sources on board: electrochemical batteries, inertial batteries, thermal batteries combined with receivers and converters.

Figure 1 presents the charge-discharge cyclograms of the indicated onboard energy sources of the spacecraft, with the notation:

W ₁ (t) is a graph of changes in the charge level of an electrochemical nickel-hydrogen storage battery, see [3, 4];

W ₂ (t) is a graph of changes in the level of charge of the inertial battery, see [5, 6];

W ₃ (t) is a graph of changes in the charge level of a heat accumulator combined with a receiver and a converter, see [6] p. 51-56.

The abscissa shows the flight time of the spacecraft, in days. On the ordinate axis is the charge level of the onboard energy sources, equivalent to the amount of transformed electric energy given under load, taking into account the efficiency of the sources (η _i ), W · hour.

Figure 2 presents on the same scale of flight time the total graph of changes in charge levels

where i = 1, 2, 3 is the number of onboard energy sources.

In addition, a graph of Wa (t) is presented — the amount of energy in ix on-board sources needed to complete the spacecraft flight program in the case of switching to maintaining the probabilistic charge level of the onboard space power sources, calculated taking into account η _i .

The power supply of the spacecraft, when the flight program is carried out by it, is carried out due to the transformation of the energy of external sources (see [1]), which are simultaneously the primary energy sources. In this case, the charge level of the onboard sources is emergency and should be used in case of violation of the technological chain in the spacecraft’s energy system during the indicated energy transformation (see [1], pp. 282-285).

For example, in the case of a loss of orientation of the SB to the Sun (see [7]), it is necessary to control the spacecraft and its rotary SB for some time using the energy of onboard power sources. It is obvious that this control process will follow the control of energy consumption on board the spacecraft. If the consumed energy on board the spacecraft exceeds the transformed energy from external sources, recorded as a result of control, the specified transition to work from onboard energy sources is performed.

It is known that monitoring the operation of systems according to the rule of its implementation can be divided into probabilistic and deterministic (see [8], p. 16). Since the control always precedes the start of the indicated control of the spacecraft’s energy supply, the energy levels of i-x onboard sources can also be divided into probabilistic and deterministic at flight time intervals. Next, we determine the flight time intervals at which we support the indicated charge levels.

Since the non-calculated loss of orientation of the spacecraft and other failures in its energy system, leading to disruption in the transformation of energy from external sources, are random in nature, the control and transition to subsequent control of the spacecraft’s energy supply from onboard sources are probabilistic.

Despite the likelihood of an implemented management rule, its occurrence is predicted through standby time. The backup time is the time during which the power supply of the spacecraft from onboard energy sources is provided until the main power supply of the spacecraft from external sources of energy is restored.

The physical meaning of the Wa (t) values lies precisely in providing the indicated reserve time of the spacecraft.

Based on the dynamic characteristics of the apparatus, the capabilities of its dynamic and kinematic contours of motion control around the center of mass, various changing factors of space flight, design features of the spacecraft and its SB, etc., the specified energy reserve can be determined.

Figure 2 in the form of a graph of Wa (t) shows the indicated current required reserve level of charge on-board energy sources, providing a backup time of the spacecraft for energy supply.

If we compare the values of the graphs W _∑ (t) and Wa (t), then we can pay attention to the fact that, on the one hand, there are “dips” in the total charge level of onboard sources below the values of Wa (t), and on the other hand, a significant excess requirements for Wa (t) energy reserves in on-board sources.

As already noted, the graph W _∑ (t) is obtained by summing the corresponding values of W _i (t) over time. Moreover, the graphs W _i (t) are presented in the form of full charge-discharge cycles of on-board sources of various types of energy.

Figure 1 presents the nominal technological cycles, according to which it is most advisable to operate on-board energy sources.

From figure 2 it can also be established that, in general, the energy reserves in the on-board sources are sufficient to provide the current values of Wa (t). This can be judged by the integrated assessment of energy reserves (area above the curve of the graph Wa (t) and its possible expenditure (area under the curve of the same graph). Moreover, the total area above the graph between the values of W _∑ (t) and Wa (t) in several times the area under the schedule.

However, as can be seen from the same graph, there are spacecraft flight time intervals at which the probabilistic charge level of onboard energy sources, which exceeds Wa (t), is not provided.

To ensure the specified level, we carry out the following actions.

и саморазряда

бортовых источников энергии.We measure the magnitude of the charge speeds

and self-discharge

onboard energy sources.

For example, for a nickel-hydrogen storage battery (NVAB) (see [4]), the generated electric energy is determined by the hydrogen pressure sensors and the case temperature:

where Rn is the pressure in the NVAB at the beginning of the discharge, kgf / cm ² ;

Pk - pressure in NVAB at the end of the discharge, kgf / cm ² ;

Тн - case temperature at the beginning of the discharge, ° С,

k is a coefficient taking into account the compressibility and consumption of H ₂ for the reaction.

The current value of the level of charge W ₁ (t) when charging is determined by the pressure P (t) and temperature T (t) by the expression

where T (t) is the current temperature on the battery case, while T (t) ∈ [Tn, Tv] is the allowable temperature range, P (t) ∈ [Rn, Tv] is the allowable pressure interval inside the NVAB casing.

и саморазряда

в данном случае определяются через измеренные значения давлений P(t) и температуры T(t), по которым определяется в соответствии с (5) W₁(t), далее определяется

и

через градиенты изменения уровня заряженностиCharge speeds

and self-discharge

in this case, they are determined through the measured values of pressures P (t) and temperature T (t), according to which it is determined in accordance with (5) W ₁ (t), then it is determined

and

through gradients of change in charge level

In this case, the charge growth gradient (grad W ₁ > 0) can be supplemented by the presence of a battery charge indicator (for example, by the presence of a charging current from a charge device), and the charge decrease gradient (grad W ₁ <0) can be supplemented by battery discharge signs (for example, by the absence of a charge current and the presence of discharge current).

The last addition is required to recognize cases associated with the abnormal operation of these batteries (for example, when the battery case is depressurized, etc.).

To determine the values of W ₂ (t), the measured parameter will be the revolutions of the rotor (flywheel) of the inertial accumulator, and for W ₃ (t), the temperature of heat-accumulating materials can be the main measured parameter.

However, regardless of the different types of batteries, the essence of the above reasoning does not change.

и

могут иметь разные значения. Однако по смене знака градиента можно определить интервалы времени заряда (t_zi, t_ri) и саморазряда (t_ri, t_zi) i-x бортовых источников, где t_zi, t_ri - моменты времени начала заряда и начала разряда i-x бортовых источников энергии, соответствующие моментам времени смены знаков grad W_i с минуса на плюс и с плюса на минус.As can be seen from the graphs shown in figure 1,

and

may have different meanings. However, by changing the sign of the gradient, it is possible to determine the time intervals of the charge (t _zi , t _ri ) and self-discharge (t _ri , t _zi ) ix of on-board sources, where t _zi , t _ri are the moments of time of the beginning of charge and the beginning of discharge ix of on-board energy sources corresponding to the points in time of changing the signs of grad W _i from minus to plus and from plus to minus.

The indicated definitions of the intervals are made within the range of values [Wn _i , Wv _i ].

In order to achieve constant fulfillment of the condition

it is necessary to recharge the sources at those time intervals at which it is not performed.

Figure 3 shows how, by changing the charge times t _z2 in the full charge-discharge cycle of the second source and interrupting the full discharge interval of the first source at a certain point in time t _zi , it is possible to ensure that condition (9) is satisfied over the entire flight interval see Fig. 4. Let us illustrate the example with a mathematical condition for a finite i-th number of onboard sources

where We (t _zi ) ∈ [Wn _i , Wv _i ] is the value of the current charge of the i-th on-board energy source We _i (t) at time t _zi .

zi приравниваем нулю для соответствующих им i-x источников, а при отсутствии саморазряда приравниваем нулю значения Wv_i и

r_i(t) для соответствующих им i-x источников.In accordance with the operating conditions, each of ix on-board sources can be either in the process of charging or in the process of self-discharge. The first half of the left side of inequality (1) reflects the charging process, and the second half - the discharge process. In the absence of a charging process, the values of We (t _zi ) and

zi we set zero for the corresponding ix sources, and in the absence of self-discharge we set Wv _i and zero

r _i (t) for their corresponding ix sources.

As can be seen from figure 3, by shifting the times t _z1 and t _z2 by the value Δt _i it was possible to ensure the fulfillment of condition (1). Thus, a graphical method for determining the times t _zi + Δt is presented. For similar purposes, we can propose an iterative method, where as variables we choose different values for Δt _i , achieving the end result of condition (1).

Following the basic decisive rule for controlling the probabilistic charge level of onboard sources, at any current moment of time, a transition to the spacecraft power supply mode from the indicated sources can be made. After the transition, the onboard current load is fully or partially provided from onboard energy sources. For power supply of the spacecraft within the framework of the current values of the values of Wa (t), the real side load should correspond to those calculated values from which the required supply of electricity was determined.

For example, with Wa (t) = 4700 W · h and a standby time of 1 hour, with a nominal voltage of 28 V, the average load current should be no more than 168 A. The specified on-board current regulators are calculated for the indicated load. Using them, we regulate the energy consumption from i-x on-board sources in accordance with the energy requirement for the spacecraft flight program.

After restoring the regular SC power supply scheme from primary energy sources and exceeding the energy transformed from external sources of energy consumed on board the SC, we produce a charge ix of the on-board energy sources to the values of Wv _i . In the process of charging these sources and their further self-discharge at time intervals (t _zi , t _ri ) and (t _ri , t _zi ) at certain points in time t _zi , we recharge the sources until condition (1) is fulfilled.

Since the charging characteristics of the onboard sources always differ from each other, it is not possible to simultaneously charge them to Wv _i , see Fig. 1, the process of charging some sources to the maximum upper level can be accompanied by interruption of self-discharge at other times t _zi , see figure 3.

Bringing the sources to the initial upper level of charge makes it possible, on the one hand, to obtain certain initial conditions for the subsequent probabilistic control of the charge levels of the onboard sources and, on the other hand, to restore the onboard energy supply as quickly as possible, providing backup time for the spacecraft’s energy supply.

In the described case, with the consumption of onboard energy reserves for the spacecraft, the situation becomes more and more critical. Therefore, the possibility of quick recovery (recovery time Wa (t)) of these reserves is one of the criteria characterizing the fault tolerance of the spacecraft energy system.

In order to increase the indicated fault tolerance, we charge on-board sources immediately after their operation under load.

During the flight of the spacecraft, situations are possible where the energy received from primary sources may not be enough to carry out the flight program. At such energy-intensive time intervals (t ₀ , t _k ), additional expenditure of energy of onboard sources is allowed. The indicated time intervals are predicted by the well-known list of included on-board equipment and electric heaters, as well as by the duration of their work. At the same time, the rated current of these consumers is, as a rule, a known value. The flight program routinely establishes both the composition of consumers and their operation diagrams, as well as the state of primary energy sources onboard the spacecraft (see [9]). Thus, the current energy balance onboard the spacecraft can be calculated from the load current and current, for example, from the solar cells. Negative values of the indicated energy balance and determine the interval (t ₀ , t _to ).

To cover the lack of energy, it is necessary to produce a determinate charge of on-board sources in order to create energy reserves onboard the spacecraft, ensuring the passage of the interval (t ₀ , t _k ) and preserving the energy reserve for the previously specified backup time.

Before the start of the interval (t ₀ , t _k ) at the time t _{0 we} determine the value ΔW (t ₀ ) of the excess of energy consumed over the transformed

ΔW (t ₀ ) = ΔW ′ (t ₀ ) / η

where In (t), Is (t) are the load currents and solar cells, respectively, A;

U is the voltage on the tires of the spacecraft power supply system, V;

- среднее значение коэффициента полезного действия i-x источников.

- the average value of the efficiency of ix sources.

We also determine the value of Wa (t _to ) at time t _{to the} end of the specified interval.

Next, we produce a deterministic charge of on-board sources at the intervals (t _zi , t _ri ) and (t _ri , t _zi ) with the beginning at certain times t _zi until the condition

We determine the current values of the current load power on ie on-board energy sources in the interval (t ₀ , t _k ):

and the total power from ix on-board energy sources (N _∑ ):

where N _i is the power of i-ro on-board source, watts.

Further, it is necessary to ensure the conditions of energy consumption (through the magnitude of the load current) under which the discharge energy from on-board sources would always provide the current energy demand on board the spacecraft. The specified condition can be written as

The fulfillment of condition (13) is ensured by distributing the current load over the interval (t ₀ , t _k ) by selecting the composition of electricity consumers.

Figure 5 shows graphs of the deterministic charge of the considered three ix sources at time t ₀ ; discharge of sources from the on-board current load in the interval (t ₀ , t _k ) and their subsequent charge.

Figure 6 shows: a graph of the charge level of on-board sources Wa (t) taking into account the required energy reserve ΔW (t ₀ ) and the predicted consumption of this reserve in the interval (t ₀ , t _k ); graph W _∑ (t) taking into account the determinate charge ix of the on-board sources at time t _o , the discharge of the sources from the current load, followed by the charge of the sources.

As can be seen from the above graphs, by choosing the start of charges at certain points in time t _zi, it was possible to ensure that condition (2) is satisfied. In addition, at time t _{k, the} current total charge level W _∑ (t _к ) exceeds the value Wa (t _к ), which ensures energy supply during the flight program at the time of transition to probabilistic discharge control ix of onboard sources immediately after the interval (t ₀ , t _k ).

In the process of power supply of the spacecraft at the indicated interval, the power of the current load from the onboard consumers should correspond to the capacity of the estimated energy consumption of the onboard sources. In this case, the planned execution of the flight program with the estimated energy supply of the device is guaranteed. To do this, we regulate the energy consumption from i-x on-board sources by connecting-disconnecting part of the on-board current load in accordance with the spacecraft flight program.

In Fig. 6, in the interval (t ₀ , t _k ), approximately the same view of the forecast portion of the graph Wa (t) and the bit segment of the graph W _∑ (t) is presented. This emphasizes that the discharge gradient of on-board sources, characterizing the change in their current power, must correspond to the current power of the current load of on-board consumers. The intersection of these graphs on the interval (t ₀ , t _k ) will characterize the borderline case, below which the graph W _∑ (t) cannot be located, since the spacecraft power supply in such cases will not be fully provided.

The above way presents a graphical solution to the problem of condition (13).

At the end of the specified interval, starting from time t _k , we produce a charge ix of on-board sources to obtain the values of Wv _i .

The indicated charge makes it possible to increase the spacecraft fault tolerance for energy supply from secondary power sources (to increase the reserve time reserve), as well as to prepare initial conditions for the subsequent maintenance of the probabilistic charge level of onboard sources.

Next, we continue the spacecraft flight with maintaining the probabilistic charge level of onboard energy sources and, as necessary, switch to the deterministic charge of these energy sources until condition (2) is satisfied.

Depending on the features of the flight program, alternations of probabilistic and determinate levels of charge of i-x onboard energy sources can be performed.

For example, in the presence of “shadow” intervals of the orbit, on which the spacecraft is obscured by the Sun from the Earth, a constant deterministic charge of onboard energy sources for the interval (t ₀ , t _k ) is determined. Since solar panels cease to generate energy in the shadow intervals of the orbit, it is necessary to recharge its onboard energy sources each time before the spacecraft enters the shadow. Then follows the power supply of the spacecraft from the indicated sources, etc.

The implementation of the proposed method can be carried out, for example, using the means of the ground control loop (GCC), the onboard control loop (GCC) and the power supply system (SES).

Figure 7 presents a functional block diagram of the elements providing the formation, transmission, reception, conversion and execution of control actions necessary for the implementation of this method, where:

1 - ground-based control complex, the formation and transfer on board of control actions (GCC),

2 - on-board equipment of the service control channel (BASKU),

3 - on-board digital computer system (BTsVS),

4 - on-board measurement system (SBI),

5 - control system for on-board equipment (SUBA),

6 - power supply system (SES).

The measurement data obtained in SBI 4 for the current parameters of the spacecraft are sent to the BCVS 3, where they are converted into arrays of control and measurement information and transmitted to BCC 1 through the means of BASKU 2.

NKU 1 provides reception of control and measuring information from the spacecraft and its display in the form necessary for analysis.

The control and measurement information obtained in this way serves as the basis for determining the charge-discharge characteristics ix of the on-board energy sources, determining the required amount of energy in the on-board sources Wa (t) for executing the spacecraft flight program, determining the charge time intervals (t _zi , t _ri ) and self-discharge (t _zi , t _ri ), determining the displacement of the beginning of the charge ix on-board sources Δt _i .

Further, in the NKU, in accordance with the previously defined parameters, the control actions are formed necessary to maintain the probabilistic charge level of the onboard sources from the time t _zi + Δt _i .

The control actions generated at NKU 1 through BASKU 2 means are supplied to BCVS 3, where they are converted into control commands corresponding to SES 6 control algorithms. The control commands obtained in this way from BTSVS 3 through SMSA 5 go to SES 6, which includes on-board sources and controls on-board sources that implement the commands received from the BCVS 3. The control actions generated on the NKU 1 can also be transmitted, bypassing the BCVS 3, along the NKU 1 circuit - BASKU 2 - SUBA 5 - SES 6, if they are not required P conversion into teams corresponding to SES 6 algorithms.

Assessment of the changes that occurred in the charge-discharge cycles of i-x on-board sources, as well as the fulfillment of condition (1), is carried out on the basis of control and measurement information on the NKU 1 obtained from SBI 4 through the SBI 4 - BTsVS - BASKU 2 - NKU 1 circuit.

In the case of determining on the basis of the obtained control and measurement information the excess of energy consumed on board the spacecraft over the transformed from external sources, control actions are formed on the interval of maintaining the probabilistic charge level on NKU 1. These effects are necessary to regulate the levels of charge sources in accordance with the previously determined energy demand for the implementation of the spacecraft flight program. The control actions generated at NKU 1 are converted and received at SES 6 through the NKU 1 - BASKU 2 - BTSVS 3 - SUBA 5 - SES 6. The changes in energy consumption from ix on-board sources are estimated based on the control and measurement information obtained at NKU 1 with SBI 4 along the chain of SBI 4 - BTsVS 3 - BASKU 2 - NKU 1.

To maintain a determinate charge level ix of on-board sources based on the SBI 4-BTsVS 3-BASKU 2-NKU 1 control and measurement information obtained from SBI 4, time intervals (t ₀ , t _k ) for maintaining a determinate charge level of onboard energy sources are predicted. The excess energy consumed over the transformed energy for the indicated intervals ΔW (t ₀ ) is determined. Using the means of NKU 1 according to the previously defined parameters, the control actions are formed that are necessary to carry out the charge before the start of the interval (t ₀ , t _k ), adjust the energy consumption from ix on-board energy sources in the interval (t ₀ , t _k ), charge ix on-board sources energy after the end of the interval (t ₀ , t _to ).

Assessment of the changes that occurred in the charge-discharge cycles of i-x on-board sources, as well as the fulfillment of condition (2), is carried out on the basis of the control and measurement information at NKU 1 obtained from SBI 4 through the SBI 4 - BTsVS 3 - BASKU 2 - NKU 1 circuit.

The positive effect of the proposed spacecraft energy management method is primarily aimed at increasing the fault tolerance of energy systems for spacecraft energy supply.

Scheduled charge control of onboard energy sources eliminates cases of insufficient energy reserves to restore regular spacecraft power supply schemes from primary external energy sources. At the same time, the necessary emergency energy supply is constantly provided, taking into account various possible scheduled operations, accompanied by the shutdown of on-board sources, emergency situations on board the vehicle and other cases related to the connection (shutdown) of these sources to power the spacecraft.

Deterministic control of the charge level of on-board sources allows you to significantly expand the possibilities of carrying out various work on board the device due to the additional expenditure (except for energy received from primary sources) of energy received from on-board sources. The possibilities for carrying out dynamic operations while controlling motion around the center of mass of the apparatus are also increasing. This is explained by the fact that orientation modes may be allowed to be performed in which it is not ensured, for example, the orientation of the SB on the Sun. Moreover, in all these cases, the availability of a reserve supply of on-board energy is guaranteed, which makes it possible to provide spacecraft control in emergency situations.

Using the proposed method also allows you to save the resource of emergency sources of electricity (if any on board), intended for limited use. Thus, it is possible to extend the life of the spacecraft as a whole.

Literature

1. A.A. Kulandin, S.V. Timashev, V.P. Ivanov. Energy systems of spacecraft. M .: Engineering, 1979

2. A.S. Eliseev. Space Flight Technique. M .: Engineering, 1983

3. B.I. Tsenter, N.Yu. Lyzlov. Metal-hydrogen electrochemical systems. L .: "Chemistry", Leningrad branch. 1989.

4. Battery with metal-gas elements. RF patent 2118873.

5. Energy storage device with a flywheel in a magnetic suspension, US patent 6019319.

6. Control of the electrical system and the spatial position control system of the artificial satellite. U.S. Patent 6,439,510.

7. Autonomous spacecraft safing with reaction wheels. Patent US 6089508.

8. Monitoring the functioning of large systems. / Edited by G.G.Shibanov. M .: Engineering. 1977

9. V.G. Kravets, V.E. Lyubinsky. The basics of space flight management. M .: Engineering. 1983.

Claims (1)

A method of controlling the power supply of a spacecraft, including determining the charge-discharge characteristics ix of the onboard energy sources of the spacecraft, including the values of the nominal upper Wv _i and lower Wn _i charge levels of these energy sources, where i = 1, 2, 3, ..., I - the number of onboard energy sources, energy transformation of external sources, measurement of charge levels We _i (t) ix onboard sources at current time t, maintaining the charge level of onboard sources within acceptable ranges the values of [Wn _i , Wv _i ] due to the transformation of the energy of external sources, control of the energy consumed on board the spacecraft during the flight program and the energy consumption of the onboard sources when the energy consumed on board the spacecraft exceeds the transformed energy from external sources, characterized in that determine flight time intervals to maintain probabilistic and deterministic energy levels ix of onboard sources, in the case of transition to maintaining probabilistic the charge level of the spacecraft’s onboard energy sources when the consumed energy exceeds the values of the transformed energy from external sources, the amount of energy in the onboard sources required to complete the spacecraft flight program Wa (t) is equivalent to the amount of transformed electric energy, then on the interval of the specified maintenance flight program the probabilistic charge level of onboard energy sources measure the magnitude of the charge speeds

on-board energy sources, as well as self-discharge rates of on-board energy sources

the specified measured values within the range of values [Wn _i , Wv _i ] determine the time intervals of the charge (t _zi , t _ri ) and self-discharge (t _ri , t _zi ) ix on-board sources, where t _zi , t _ri are the moments of time of the beginning of charge and the onset of discharge ix on-board energy sources, respectively, determine the charge onset ix of on-board sources Δt _i , providing the required amount of on-board source energy Wa (t), and maintain the charge level of on-board sources from time t _zi + Δt _i at intervals (t _zi , t _ri ) and (t _ri , t _zi ) until Wii

where We (t _zi ) ∈ [Wn _i , Wv _i ] is the value of the current charge i-ro of the on-board source We _i (t) of energy at time t _zi , and if the energy consumed on board the spacecraft is transformed from external sources by the interval of maintaining the probabilistic level of charge, adjust the energy consumption from ix onboard sources in accordance with the energy requirement for the flight program of the spacecraft, and then when the energy transformed from external sources exceeds the energy consumed on board the spacecraft nical apparatus produce charge ix onboard power sources to values Wv _i and maintained their levels of charge on the time intervals (t _zi, t _ri) and (t _ri, t _zi) from time t _zi + Δt _i to the condition (1) and during execution of mission spacecraft predict time intervals (t _0, t _k) maintaining the determined level of charge of the onboard power sources in which the energy consumption exceeds transformable from an external source, determine the value ΔW (t ₀₎ excess energy consumed transformable energy needs to these intervals are determined Wa value (t _k) at the time of the end time interval (t _0, t _k) and prior to the predicted interval t ₀ produce deterministic charge onboard sources intervals (t _zi, t _ri) and (t _ri , t _zi ) from the time t _zi + Δt _i until the condition

further, in the process of executing the flight program, on the interval (t ₀ , t _k ), the energy consumption from ix on-board sources is regulated in accordance with the amount of energy required to execute the flight program of the spacecraft, while ensuring that the discharge energy received from on-board sources exceeds the energy consumed on board the spacecraft, and after the predicted interval from time t _to produce a charge ix board sources to obtain Wv _i values in order to maintain ver yatnostnogo charge level of said on-board sources to satisfy the condition (1) and as needed to pass the above deterministic charge the onboard power sources to satisfy the condition (2), then alternated as aforesaid maintenance of probabilistic and deterministic charge levels ix onboard energy sources.

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