RU2692301C1 - Control method of power supply system of spacecraft of increased survivability - Google Patents

Abstract

FIELD: electrical engineering.SUBSTANCE: invention relates to electrical engineering, specifically autonomous power supply systems (PSS) of spacecraft (SC), using as primary sources of energy photovoltaic batteries (PB), and as energy storage – accumulator batteries (AB). Charging and discharging devices are controlled. Prohibition of discharge device operation is performed when minimum charge level is reached and prohibition is removed at increase of charge level. Control signal is generated to disconnect part of onboard equipment at emergency discharge of several m (m≤n) AB to minimum level of charge. Operation of all discharge devices is inhibited if output voltage of PSS drops to preset threshold value. Control signal storage is reset to prohibit all discharge devices after charging all the batteries to the specified level of charge. PSS parameters are readout. Readout is performed from automation and voltage stabilization complex via multiplex exchange channel. Total depth of discharge of all the accumulators is calculated and the calculated total depth of the discharge is compared with the threshold values given in the on-board PSS program. Repeated reading of PSS parameters, duration of setting is selected, comparable with period of updating information on PSS parameters. Again, comparison with threshold values of total discharge depth is performed, generating/not generating control signal in onboard control system to change operating mode of spacecraft.EFFECT: higher reliability and survivability of PSS and spacecraft as a whole.1 cl, 2 dwg

Description

The present invention relates to electrical engineering, namely to autonomous power supply systems (BOT) of spacecraft (SC), using photovoltaic (BP) batteries as primary energy sources and batteries (AB) as energy storage devices.

An integral part of the modern BOT spacecraft in addition to the BF and AB is onboard automation, for example, the complex automation and voltage regulation (CAS) for the EPC KA. The UAN stabilizes the voltage at the BOT output within the range of the load current, coordinates the work of the BF and AB, transmits information about the BOT parameters to the onboard control complex (BKU) and the onboard telemetry measurement system. The number of measures aimed at improving the specific characteristics of the BOT should include the introduction into practice of a multiplex exchange channel (MCO) for the implementation of electrical and informational links between the control center and the CAS BOT. However, the use of the most sophisticated electronic equipment in the composition of EPAs KA with a long active life, as a rule, leads to an increase in the probability of occurrence of failures or single failures in it, including such transmission from AIS to on-board software (BEP) distorted (unreliable) information that does not correspond to the real state of the system.

One of the main tasks of BPO BOT is the periodic monitoring of the total depth of discharge of the battery. In case of exceeding one of the predefined thresholds for the discharge depth of the AB, the BOT program should activate the control mode program when there are faults to transfer the product to oriented flight on duty (ODP) or, if larger, to the duty orientation mode (RDD) to disable part of the onboard equipment.

A known method of controlling the power supply system of a spacecraft (Kirilin A.N., Akhmetov R.N., Storozh A.D., Anshakov G.P. Space Apparatus Engineering. State Research and Production Rocket and Space Center "TsSKB-Progress", the city of Samara, 2011, analog), which consists in the management of charging and discharge devices, depending on the input and output voltages of the power supply system; monitoring the state of charge of the batteries; the prohibition of the work of the corresponding charger when the maximum level of charge of this battery is reached and the ban is lifted while the level of charge is lowered; a ban on the operation of the corresponding discharge device when the established minimum level of charge (or voltage) of this battery is reached and the ban is lifted when the level of charge (voltage) of the battery is increased.

The disadvantage of the analogue is that it does not allow to increase the reliability and survivability of the operation of the EPS in the event of a violation of the energy balance for any reason, with negative consequences.

There is a method of controlling an autonomous power supply system of a spacecraft (RF patent for invention No. 2467449, prototype) containing a solar battery and n batteries, a voltage stabilizer connected between the solar battery and the load, and n charging and discharging devices. control voltage regulator, charging and discharging devices depending on input and output voltages of the power supply system; control the state of charge of the batteries; imposing a ban on the operation of the corresponding charger when the maximum charge level of the battery is reached and removing the ban when the charge level is reduced; impose a ban on the operation of the corresponding discharge device when the specified minimum charge level of the battery is reached and remove the ban when the charge level of the battery is increased; control the output voltage of the power supply system using a threshold sensor; in case of emergency discharge of several m (m≤n) batteries to the minimum level of charge, a control signal is formed into the onboard control system of the spacecraft to turn off part of the onboard equipment and memorize it; in case of emergency discharge of all n working batteries to the minimum level of charge, the ban on the operation of all discharge devices is lifted; if after memorizing the control signal, the output voltage of the system decreases to a predetermined threshold value, the operation of all discharge devices is prohibited; Resetting the control signal is performed after charging all batteries or by external one-time command.

The disadvantage of the prototype is that it does not have the ability to reflect inaccurate (bad) information about the charge levels of the AB at the current time, the results of the analysis of which can form control actions in the onboard control complex on the changes in the operating modes of the spacecraft, which leads to a decrease in reliability and survivability of functioning BOT.

The task of the invention is to improve the reliability and survivability of the EPA and KA as a whole.

This problem is solved by the fact that in the method of controlling the power supply system of a spacecraft of increased survivability, containing a photovoltaic battery and n rechargeable batteries and n charging and discharging devices, consisting in controlling charging and discharging devices depending on the illumination of the BF, the state of charge of all ABs, the input and the output voltage of the power supply system; the introduction of a ban on the operation of the corresponding discharge device when the established minimum level of charge of this battery is reached and the ban is lifted when the level of charge of this battery is increased; forming a control signal in the onboard control complex of the spacecraft to turn off part of the onboard equipment during emergency discharge of several m (m≤n) AB to the minimum charge level; the prohibition of the operation of all bit devices, if the output voltage of the BOT is reduced to a predetermined threshold value; resetting the memorization of the control signal to prohibit all bit devices after charging all ABs to a predetermined charge level; using the on-board software BOT from the on-board software (BPO) of the on-board control complex, read the BOT parameters, including the charge levels of the AB; in this case, the reading is carried out from the CAS via a multiplex exchange channel; using the BOT parameters, calculate the total depth of discharge of all ABs and compare the calculated total depth of the discharge with the threshold values specified in the on-board BOT program for generating a control signal in the on-board control complex values; in case the discharge depth threshold is exceeded, the readout of the EPS parameters is repeated through the time setpoint, and the duration of the setpoint is chosen that is comparable to the update period of information about the EPF parameters; after re-calculating the total depth of the discharge, the AB is again compared with threshold values of the total depth of the discharge and, depending on their ratio obtained, use the EPS algorithm to generate / not generate a control signal in the onboard control complex for changing the operating mode of the spacecraft.

An example of a functional FEP scheme in which the proposed method is implemented is shown in FIG. 1, where indicated:

1 - photovoltaic battery;

2 - voltage regulator (СН) with extreme power regulator (ЭРМ) БФ;

3 ₁ ... 3 _n - chargers (chargers);

4 ₁ ... 4 _n - bit devices (RU);

5 ₁ ... 5 _n - batteries;

6 ₁ ... 6 _n - devices for monitoring the state of charge of the battery (UKZAB);

OS - feedback input;

3 - entry ban work;

7 - load BOT (onboard equipment);

8 - threshold threshold voltage sensor;

9 - logical element m of n;

10 - logical element And;

11, 12 ₁ ... 12 _n , 13 ₁ ... 13 _n , 14 ₁ ... 14 _n - RS triggers;

15 - logical element And;

16 ₁ ... 16 _n , 17 ₁ ... 17 _n - logical elements OR,

18 - capacity meter AB and the terminal device (OU)

19 - BKU with BPO, including BPO BOT.

Management autonomous power supply system of the spacecraft is as follows (Fig. 1). BOT is a continuous control voltage regulator, charging and discharge devices, as well as solar panels, depending on the illumination of the BF, the input (voltage BF) and the output voltage of the BOT. In this case, the chargers provide an AB 5 ₁ ... 5 _n charge, and the SN and RU provide power to the onboard equipment (BA) 7. Continuous control circuits (feedback - OS) The charger is connected to the bus BF 1, and the continuous control circuits (OS) CH and RU connected to the output bus BOT (input BA 7).

Depending on the state of charge of the battery, a ban is made or the permission to operate the memory device and the switchgear. When the maximum state of charge of a particular AB is reached, the signal from the “Memory lock” output of its battery charge control device (6 ₁ ... 6n in Fig. 1), by means of RS trigger (12 ₁ ... 12 _n ), prohibits the operation of its charger. After the discharge of the battery to a certain predetermined level, this prohibition is removed by a signal from the output "Permission of memory" UZZAB.

When the minimum level of charge of a particular AB is reached, the signal from the output of the “Ban on RU” of its UKZAB (6 ₁ ... 6n in the drawing), passing through the RS trigger (14 ₁ ... 14 _n ) and the OR gate (17 ₁ ... 17 _n ) is fed to the prohibition of the work of the relevant RU. This AB is translated into storage mode. After charging this AB to a certain predetermined level, this prohibition is removed by the signal from the output “Resolution RU” of UKZAB (logical elements OR 16 ₁ ... 16 _n , RS triggers 14 ₁ ... 14 _n , logical elements OR 17 ₁ ... 17 _n ).

In the case of an abnormal orientation of the solar cells of a spacecraft on the Sun, there is a violation of the energy balance in the EPS. The signals from the outputs "Ban RU" of all UKZAB are fed to the inputs of logic elements 9 (m from n) and 10 (logical element I).

When an emergency discharge of several m (m≤n) batteries to the minimum level of charge at the output of the logic element 9, an emergency load control signal (“AN”) is generated, which is output to the onboard control complex to disable part of the BA. This signal is stored on the R-S trigger 11. Memorization is removed by an external one-time command (RC). When the ACU part of the BA is disconnected, the rate of energy consumption of the AB decreases. A part of the BA remains connected — devices of thermal control systems, telemetry, and other necessary systems. These devices provide temperature regimes and control of BA 7 parameters. It becomes possible to power the load for a longer time and to continue work on the decommissioning of the spacecraft from an abnormal situation. Thus, it is possible to use means of the onboard control complex for adaptive change of the BA power supply circuit 7 depending on the current state of the energy capabilities of the EPS.

When the emergency discharge of n working AB 5 ₁ ... 5 _n to the minimum level of charge at the output of NAND gate 10 receive a signal which passes through OR gates 16 ₁ ... 16 _n, RS flip-flops 14 ₁ ... 14 _n, the logical elements or 17 ₁ ... 17 _n removes a ban on the operation of all bit devices. Further, if the emergency situation continues, a synchronous discharge occurs for the remainder of the load of all AB 5 ₁ ... 5 _n . The available capacity of AB is fully utilized.

Upon further emergency discharge, the output voltage of the system decreases to a predetermined threshold value, the threshold sensor of the minimum voltage 8 is triggered, and since this was preceded by storing the control signal “AN” on RS trigger 11, its signal passing through the AND 15 and RS triggers (13 ₁ ... 13 _n) and OR gates (17 ₁ ... 17 _n) prohibits operation of all bit devices and the logic level at the inputs OR (17 ₁ ... 17 _n) blocks the passage of control signals enables the discharge unit n signals from the level of charge UKZAB 6 ₁ ... 6 _n .Zapominanie control signal "AN" provides protection against power failure BA 7, with a false positive threshold sensor undervoltage 8, or when it is triggered in case of an overload on the output buses SEP unrelated to the orientation of the violation BF 1 and emergency discharge of AB.

After restoring the orientation of BF 1 to the Sun, the remaining included part of BA 7 is powered from BF 1 through a voltage stabilizer. The voltage at the output of the BOT, provided by the SN, is determined by the ratio of the power of the load 7 connected to the output buses of the BOT, and the power generated by BF 1 and determined by the degree of its illumination. Voltage BF 1 and, therefore, the voltage BA 7 can vary arbitrarily for an indefinite time, until the orientation is fully restored, from 0 to the nominal value. Included devices, of course, while maintaining their performance. Excess power BF 1 is on charge of the AB 5 ₁ ... 5 _n .

Since the continuous control circuits (feedback - OS) of the charger are connected to the BF bus, and the continuous control circuits (OS) of the SN are connected to the output bus of the EPF, the power supply of the BA 7, that is, the included instruments of the thermal control system, telemetry systems, and other necessary systems that will provide the necessary temperature regimes of chargers and batteries, as well as control parameters. In case of violation of the orientation of BF 1 on the Sun or the departure of the spacecraft into the shadow, the power supply of the entire BA 7 and the charge of the AB 5 ₁ ... 5 _n stops. Discharge AB 5 ₁ ... 5 _{n is} not performed, because the signal "Discharge prohibition" is not removed.

When charging any of the batteries 5 ₁ ... 5 _n up to a certain capacitance value, the signal from the output of the UKZAB AB is charged, passing through RS a trigger (13 ₁ ... 13 _n ) and a logical element OR (17 ₁ ... 17 _n ) removes the prohibition for the operation of their discharge device and blocking the passage of control signals that permit the operation of the discharge devices by signals about the level of charge from UKZAB 6 ₁ ... 6 _n . BOT enters normal operation after charging all AB 5 ₁ ... 5 _n or RK.

For autonomous monitoring and control of BOT, i.e. without interference from the ground control complex, as part of BKU 19, BOT use BOT algorithms (BEP BOT), which receive the necessary information from the BOT via a duplicated multiplex exchange channel. For the formation and transmission of information about the state of the BOT, including the values of the capacitance of the battery, in the BOT use the capacitance meter of the battery and the terminal device (OS) 18. BPO BOT periodically reads the ICE from the shelter of the EPS, information about the levels of charge of the battery.

The application of the proposed method of controlling the power supply system of the spacecraft allows maximum use of the accumulated AB capacity and provide power to the onboard control complex to halt or restrain the development of an emergency situation, as well as prevent irreversible discharge of the AB 5 ₁ ... 5 _n in the event of an energy balance violation. Thus, the application of the proposed method of controlling power supply to spacecraft of increased survivability can significantly reduce the likelihood of an emergency due to a violation of the energy balance.

Improving the reliability and survivability of the EPC KA is carried out by using BPO EPD.

FIG. 2 shows an example of a block diagram of the control logic of the industrial control unit of EPC with preliminary processing of the parameter values in order to counter the receipt of faulty information about the depths of the discharge from the CAS.

Through the on-board program, the BOT from the onboard software of the on-board control complex with a specified frequency read the parameters of the BOT, including the levels of charge of the battery (block B). Reading is carried out from UAN on multiplexed exchange channel. Using the parameters of the BOT, calculate Q _∑ - the total depth of discharge of all ABs (block B), as the difference between the full and current levels of the charge of the AB, and make a comparison (block C) of the calculated total depth of the discharge with the specified threshold for the formation of the control signal value P ( transfer of spacecraft to PDP). When Q _∑ <P, the algorithm continues to work by periodically monitoring the total depth of the discharge (block K) with resetting the program indicator of re-removal α _repetition (block J) (the initial value of the characteristic _repetition α is zero). If Q _∑ exceeds the threshold value P, then in order to protect the product from unauthorized transfer to ODP or RDO due to the possible receipt of faulty information about the state of charge of the battery by the BOT algorithm, the updated array is repeated after the time Δt (the sign of _{repetition is} formed as a single) ( blocks E, F, G, B). If the second removal confirms that the depth of discharge of the threshold value is exceeded for transferring to the MTO (blocks B, C), then it is considered reliable, and actions are taken to transfer the product to the MTO or RDO (blocks D, H); if the second removal showed normal depths of discharge of the battery not exceeding the EIR threshold (block C), then this removal is considered correct, and the information of the previous removal is considered unreliable, and regular work continues without translation into EDP or RDO (blocks J, K).

That is why, in case of exceeding the threshold value of the discharge depth through the time setpoint Δt, the readout of the BOT parameters is repeated. To reflect the faulty information, the duration of the setpoint Δt is chosen, comparable to the period of updating the data sets on the BOT parameters in the CAS registers. Only in this case, the faulty information will not appear in the array of BOT parameters by the time of the repeated (control) removal. After re-calculating the total depth of the discharge, the ABs are again compared with threshold values of the total depth of the discharge and, depending on their ratio obtained, use the EPC algorithm to generate / not generate a control signal in the control unit for changing the operating mode of the spacecraft.

The condition for checking the values of the capacitance of the battery for reliability is the appearance of the fact that the total depth of the discharge, calculated by the BOT program, exceeds the threshold value of the transfer to the DCT. It is enough to compare the depth of the discharge of the battery only with the threshold of transfer to the MDP, since RDO threshold is lower and therefore if the RDO threshold is exceeded, the EIR threshold will also be exceeded (from the point of view of power consumption, full-time work (SR), RPD, RDO, the products go in descending order, that is, when SR is the largest consumption, at RDO - the smallest among the SR, ODP, RDO; therefore, the threshold of the discharge depth for transferring the product to ODP is less than for transfer to the ODS).

Only those battery levels that lead to control actions on the spacecraft are subject to validity testing (“cleaning”). A possible failure of the parameter values to another range, for example, in the case of a “over-scale” on the upper values of the AB capacitances, is not subjected to a recheck. It is assumed that failures are single and self-eliminating, i.e. The following survey after the exposure of a sufficient pause required for updating the arrays in the CAS should show reliable information.

Thus, the application of the proposed method of controlling the power supply system of the spacecraft allows to increase the reliability and survivability of the EPS and the spacecraft as a whole, since it excludes cases of incorrect transfer of the product to the EIR or RDO mode with consequent negative consequences.

Claims (1)

The method of controlling the power supply system of a spacecraft of increased survivability, containing a photovoltaic battery (BF), n batteries (AB) and n charging and discharging devices, consisting in controlling charging and discharging devices depending on the illumination of the BF, the degree of charge of all AB , input and output voltage of the power supply system (EPS); impose a ban on the operation of the corresponding charger when the maximum charge level of a given battery is reached and lifts this ban while reducing the level of charge of a given battery; impose a ban on the operation of the corresponding discharge device when the prescribed minimum level of charge of this battery is reached and remove this ban when the level of charge of this battery is increased; form a control signal to the onboard control complex (BCU) of the spacecraft (SC) to turn off part of the onboard equipment during emergency discharge of several m (m≤n) AB to the minimum charge level; prohibit the operation of all bit devices, if the output voltage of the BOT is reduced to a predetermined threshold value; make a reset of the control signal for the prohibition of all bit devices after charging all ABs to a given level of charge, characterized in that through the on-board program BOT from the on-board software (BPO) of the on-board control complex with a given periodicity, the parameters of BOT are read, including charge levels AB; however, the reading is carried out from the complex of automation and voltage stabilization through a multiplex exchange channel; using the parameters of the BOT, calculate the total depth of discharge of all AB and make a comparison of the calculated total depth of the discharge with specified in the onboard program of the BOT threshold values for the formation in the on-board control complex control signal; in case of exceeding the threshold value of the discharge depth through the time setpoint, the readout of the BOT parameters is repeated, and the set time duration is chosen comparable to the update time of the BOT parameters; after re-calculating the total depth of the discharge, the AB is again compared with threshold values of the total depth of the discharge and, depending on their ratio obtained, use the EPS algorithm to generate / not generate a control signal in the onboard control complex for changing the operating mode of the spacecraft.

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