CN106208038A - A kind of spacecraft double-bus Energy Balance Analysis method - Google Patents

Abstract

The invention discloses a kind of spacecraft double-bus Energy Balance Analysis method, comprise the steps:, by measuring solar incident angle and solar battery array shielded area, to calculate solar wing output；By measuring the percentage ratio of cable waste power and electrical equipment general power, computational load demand power；By calculating the difference of solar wing output and load demand power, determine the duty of accumulator；Judge the charged form of accumulator, by calculating charging current and discharge current, determine accumulator current capacities；According to accumulator initial capacity, accumulator current capacities and accumulator total capacity, assess storage battery energy poised state；The present invention is by the judgement to battery state of charge, distinguish the impact on accumulator electric-quantity of the different busbar voltages under double-bus, improve the computational accuracy of the double-bus crossfeed energy balance, solve double-bus crossfeed accumulator electric-quantity and calculate complicated problem.

Description

Spacecraft double-bus energy balance analysis method

Technical Field

The invention relates to a spacecraft double-bus energy balance analysis method, which is particularly suitable for energy planning of a power supply system of a spacecraft and belongs to the technical field of spacecraft energy balance control.

Background

The energy balance analysis is a design basis of the spacecraft, provides a power supply magnitude design basis for a power supply system, and provides energy planning for the on-orbit operation of the spacecraft. The spacecraft double-bus system comprises two buses, namely a non-adjusting bus and a full-adjusting bus, is mainly used in the field of power large-pulse loads and combined spacecrafts, and is an important development direction of spacecrafts.

The traditional spacecraft energy balance analysis method only performs energy balance analysis on a single bus, is low in calculation precision, only considers a fixed value for bus voltage, is single in shielding rate condition, and does not consider the trickle charge condition of a storage battery. In an article, design and application of an energy balance analysis system of a spacecraft assembly (spacecraft engineering, Vol.22, No.2, P60-64), charging capacity of a storage battery in an illumination area, consumption capacity of a grid-connected storage battery and discharge capacity of a shadow area are calculated for the energy balance analysis system of the spacecraft assembly respectively, and the calculation is complex, and the conditions of different bus voltages, trickle charging and the like are not considered.

The traditional spacecraft energy balance analysis method cannot solve the following problems of double-bus energy balance: the solar cell arrays corresponding to the two buses have different shielding conditions, the two buses have different voltages, the two buses supply power in a crossed manner, and the storage battery is charged in a trickle manner.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the invention overcomes the defects of the prior art, and provides a spacecraft double-bus energy balance analysis method, which distinguishes the influence of different bus voltages under double buses on the electric quantity of a storage battery through judging the charging state of the storage battery, improves the calculation precision of double-bus cross power supply energy balance, and solves the problem of complex calculation of the electric quantity of the storage battery under double-bus cross power supply; the output power under the shielding condition of the two bus solar cell arrays is respectively calculated, so that the parameters required by accurately calculating the energy balance state of the spacecraft are realized, and the problem that the real-time output power of the solar wing is inaccurate is solved; by comparing the chargeable current of the storage battery, whether the storage battery is in trickle charge or not is effectively judged, and the charging electric quantity is accumulated in the charging electric quantity of the storage battery, so that the defect that the trickle charge state of the storage battery cannot be calculated is overcome.

The technical solution of the invention is as follows:

a spacecraft double-bus energy balance analysis method comprises the following steps:

the first step is as follows: calculating the output power of the solar wing by measuring the solar incident angle and the shielding area of the solar cell array;

the second step is that: calculating the power required by the load by measuring the percentage of the loss power of the cable to the total power of the electric equipment;

the third step: determining the working state of the storage battery by calculating the difference value between the output power of the solar wing and the required power of the load;

the fourth step: judging the charging form of the storage battery, and determining the current capacity of the storage battery by calculating the charging current and the discharging current;

the fifth step: and evaluating the energy balance state of the storage battery according to the initial capacity of the storage battery, the current capacity of the storage battery and the total capacity of the storage battery.

In the above method for analyzing the energy balance of the spacecraft double-bus, the criterion for evaluating the energy balance state of the storage battery is as follows: if C₀-C_d+C_cIf the carbon content is more than or equal to C, the energy is balanced; if C₀-C_d+C_cIf < C, the energy is not balanced.

Wherein: c₀Is the initial state capacity of the storage battery; c_dThe discharge capacity of the storage battery is shown; c_cCharging capacity for the battery; and C is the total capacity of the storage battery.

Sun of the sunThe wing output power comprises the full-regulated solar wing output power P_QSWithout adjusting the output power P of the solar wing_BS。

The load demand power comprises the fully regulated bus load demand power and the unregulated bus load demand power;

the calculation formula of the total regulated bus load required power is P_QL＝(1-η_QL)P_Q0；

Wherein: p_QLTo fully regulate the bus load demand power, η_QLFor fully regulating the loss power ratio, P, of the busbar cable_Q0The total power of the bus electric equipment is fully adjusted;

the calculation formula of the demand power of the unregulated bus load is P_BL＝(1-η_BL)P_B0；

Wherein: p_BLTo not regulate the bus load demand power, η_BLTo not adjust the loss power ratio of the bus cable, P_B0The total power of the bus electric equipment is not regulated.

The working state of the storage battery comprises a charging state and a discharging state, and in the double-bus system, the full-regulation bus and the non-regulation bus supply power in a crossed manner;

when P is present_QS－P_QLWhen the current value is more than or equal to 0, the working state of the storage battery is determined by the following formula:

if (P)_QS-P_QL) The + PBS-PBL is more than or equal to 0, and the storage battery is in a charging state;

if (P)_QS-P_QL)+PBS-PBL<0, the storage battery is in a discharging state;

when P is present_QS－P_QLWhen < 0, the operating state of the battery is determined by the following formula:

if it isThe storage battery is in a charging state;

if it isThe storage battery is in a discharging state;

in the formula η_dThe discharge regulator works efficiently.

The current capacity of the battery comprises a battery charge capacity C_cAnd battery discharge capacity C_d；

When P is present_QS-P_QL≥0，P_QS-P_QL+P_BS-P_BLWhen the content is more than or equal to 0,

$C_c=\underset{i=1}{\overset{n}{\&Sigma;}}{I}_{ci}\&CenterDot;{\mathrm{\&eta;}}_c\&CenterDot;T_i=\underset{i=1}{\overset{n}{\&Sigma;}}min(\frac{P_{QS}-P_{QL}}{V_{BUS}}+\frac{P_{BS}-P_{BL}}{V_{BAT}},\frac{V_{BAT0}-V_{BAT}}{R_{BAT}})\&CenterDot;{\mathrm{\&eta;}}_c\&CenterDot;T_i;$

when in useWhen the temperature of the water is higher than the set temperature,

$C_c=\underset{i=1}{\overset{n}{\&Sigma;}}{I}_{ci}\&CenterDot;{\mathrm{\&eta;}}_c\&CenterDot;T_i=\underset{i=1}{\overset{n}{\&Sigma;}}min(\frac{P_{QS}-P_{QL}}{V_{BUS}{\mathrm{\&eta;}}_d}+\frac{P_{BS}-P_{BL}}{V_{BAT}},\frac{V_{BAT0}-V_{BAT}}{R_{BAT}})\&CenterDot;{\mathrm{\&eta;}}_c\&CenterDot;T_i;$

wherein,can be used for judging whether trickle charge is needed or not whenAt the moment, the storage battery adopts a trickle charge mode, and the charging current of the storage battery is

Wherein, I_ciCharging current at time i η_cTo the charging efficiency; t is_iThe charging time at the ith moment; n is the total charging time period number; v_BUSTo fully regulate the bus voltage; v_BATThe voltage of the storage battery is not adjusted; v_BAT0Is the nominal voltage of the storage battery; r_BATThe equivalent internal resistance of the storage battery.

Discharge capacity C of storage battery_dDetermined by the discharge current and the discharge efficiency of the battery:

when P is present_QS-P_QL≥0，P_QS-P_QL+P_BS-P_BLWhen the ratio is less than 0, the reaction mixture is,

$C_d=\underset{i=1}{\overset{n}{\&Sigma;}}{I}_{fi}/{\mathrm{\&eta;}}_d\&CenterDot;\mathrm{\&Delta;}T=\underset{i=1}{\overset{n}{\&Sigma;}}|\frac{P_{QS}-P_{QL}}{V_{BUS}}+\frac{P_{BS}-P_{BL}}{V_{BAT}}|/{\mathrm{\&eta;}}_d\&CenterDot;\mathrm{\&Delta;}T;$

when in useWhen the temperature of the water is higher than the set temperature,

$C_d=\underset{i=1}{\overset{n}{\&Sigma;}}{I}_{fi}/{\mathrm{\&eta;}}_d\&CenterDot;\mathrm{\&Delta;}T=\underset{i=1}{\overset{n}{\&Sigma;}}|\frac{P_{QS}-P_{QL}}{V_{BUS}}+\frac{P_{BS}-P_{BL}}{V_{BAT}}|/{\mathrm{\&eta;}}_d\&CenterDot;\mathrm{\&Delta;}T;$

wherein, I_fiDischarge current at time i η_dTo discharge efficiency; and delta T is the discharge time of the storage battery.

Compared with the prior art, the invention has the beneficial effects that:

1. according to the invention, through the judgment of the charging state of the storage battery, the influence of different bus voltages under the double buses on the electric quantity of the storage battery is distinguished, the calculation precision of the double-bus cross power supply energy balance is improved, and the problem of complex calculation of the electric quantity of the storage battery under the double-bus cross power supply is solved.

2. According to the method, the output power under the shielding condition of the two bus solar cell arrays is respectively calculated, so that the parameters required by accurately calculating the energy balance state of the spacecraft are realized, and the problem that the real-time output power of the solar wing is inaccurate is solved.

3. The trickle charge state of the storage battery can be calculated by comparing the chargeable current of the storage battery, so that the trickle charge state of the storage battery can be calculated.

4. The method has the advantages of smooth logic, clear thought and reasonable design, and the technical personnel in the field can quickly analyze the energy balance state of the large pulse type load and the combined spacecraft by performing experiments according to the steps of the method.

5. The invention has safe and reliable test process and wider application range, and reduces the operation burden of workers.

6. The invention takes the battery discharge depth not higher than the preset value as the starting point to carry out energy balance management, so that the spacecraft double-bus has the capability of bearing higher load.

7. The invention realizes the high-precision energy balance control of the double buses of the spacecraft when the shielding conditions of the solar cell array are different, the voltages of the two buses are different, the two buses supply power in a crossed way and the storage battery is charged trickle.

Drawings

FIG. 1 is a flow chart of the present invention

FIG. 2 is a diagram showing the relationship between the voltage of the battery and the capacity of the battery according to the present invention

Detailed Description

The invention will be further described with reference to the following description and specific examples, taken in conjunction with the accompanying drawings:

as shown in fig. 1, a spacecraft double-bus energy balance analysis method includes the following steps:

the first step is as follows: calculating the output power of the solar wing by measuring the shielding area and the solar incident angle of the solar cell array; the output power of the solar wing comprises the output power P of the fully-regulated solar wing_QSWithout adjusting the output power P of the solar wing_BS。

i₀Constantly and fully adjusting output power of bus solar wingWherein, P_QS0For fully regulating the rated output power S of the solar wing of the bus when the solar incident angle is 0 DEG_QSZFor fully adjusting the shielding area of the bus solar cell array, S_QSThe area of the bus solar wing is fully adjusted.

When the area of the solar wing of the full regulating bus is 2m²The shielding area of the solar wing of the full regulating bus is 0.1m²When the solar incident angle is 10 degrees and the rated output power of the solar wing of the full regulating bus is 500W, the output power P of the solar wing of the full regulating bus is obtained by calculation_QSIs 467.78W.

i₀Constantly, the output power of the bus solar wing is not adjustedWherein, P_BS0In order not to adjust the rated output power S of the solar wing when the sun incident angle of the bus is 0 DEG_BSZIn order not to adjust the shielding area of the bus solar cell array, S_BSFor not adjusting the area of the solar wing of the bus。

When the area of the solar wing of the bus is not adjusted to be 6m²The shielding area of the solar wing is not adjusted to be 0.2m²When the sun incident angle is 10 degrees and the rated output power of the solar wing of the unadjusted bus is 1500W, calculating to obtain the output power P of the solar wing of the unadjusted bus_BSIs 1427.97W.

The second step is that: calculating the power required by the load by measuring the percentage of the loss power of the cable to the total power of the electric equipment; the load demand power comprises the fully regulated bus load demand power and the unregulated bus load demand power;

the calculation formula of the total regulated bus load required power is P_QL＝(1-η_QL)P_Q0(ii) a (formula 1)

Wherein: p_QLTo fully regulate the bus load demand power, η_QLFor full regulation of bus cable loss ratio, P_Q0The total power of the bus electric equipment is fully regulated.

i₀At the moment, the loss rate of the cable of the full-regulation bus is 0.03, the total power of the electric equipment of the full-regulation bus is 450W, and the load required power of the full-regulation bus is 436.5W through calculation.

The calculation formula of the demand power of the unregulated bus load is P_BL＝(1-η_BL)P_B0(ii) a (formula 2)

Wherein: p_BLTo not regulate the bus load demand power, η_BLTo not adjust the bus cable loss rate, P_B0The total power of the bus electric equipment is not regulated.

i₀At the moment, the loss rate of the non-regulated bus cable is 0.04, the total power of the fully-regulated bus electric equipment is 878W, and the load required power of the fully-regulated bus is 842.88W through calculation.

The third step: determining the working state of the storage battery by calculating the difference value between the output power of the solar wing and the required power of the load;

when P is present_QS－P_QLWhen the current value is more than or equal to 0, the working state of the storage battery is determined by the following formula:

if (P)_QS-P_QL) The + PBS-PBL is more than or equal to 0, and the storage battery is in a charging state; (formula 3)

If (P)_QS-P_QL)+PBS-PBL<0, the storage battery is in a discharging state; (formula 4)

When P is present_QS－P_QLWhen < 0, the operating state of the battery is determined by the following formula:

if it isThe storage battery is in a charging state; (formula 5)

If it isThe storage battery is in a discharging state; (formula 6)

In the formula η_dThe discharge regulator works efficiently.

i₀Time of day, P_QS－P_QL＝467.78-436.5＝31.28>0，

(P_QS-P_QL) + PBS-PBL-467.78-436.6 + 1427.97-842.88-616.27, the battery is in a charged state.

The fourth step: judging the charging form of the storage battery, and determining the current capacity of the storage battery by calculating the charging current and the discharging current;

the current capacity of the battery comprises a battery charge capacity C_cAnd battery discharge capacity C_d；

When P is present_QS-P_QL≥0，P_QS-P_QL+P_BS-P_BLWhen the content is more than or equal to 0,

when in useWhen the temperature of the water is higher than the set temperature,

wherein, in formula 7Can be used for judging whether trickle charge is needed or not

Electricity whenAt the moment, the storage battery adopts a trickle charge mode, and the charging current of the storage battery isThe same applies to equation 8.

Wherein, I_ciCharging current at time i η_cTo the charging efficiency; t is_iThe charging time at the ith moment; n is the total charging time period number; v_BUSTo fully regulate the bus voltage; v_BATThe voltage of the storage battery is not adjusted; v_BAT0Is the nominal voltage of the storage battery; r_BATThe equivalent internal resistance of the storage battery.

Discharge capacity C of storage battery_dDetermined by the discharge current and the discharge efficiency of the battery:

when P is present_QS-P_QL≥0，P_QS-P_QL+P_BS-P_BLWhen the ratio is less than 0, the reaction mixture is,

when in useWhen the temperature of the water is higher than the set temperature,

wherein, I_fiDischarge current at time i η_dTo discharge efficiency; and delta T is the discharge time of the storage battery.

i₀At the moment, the battery is judged to be in the charging state through the third step, and at the moment, the charging efficiency η_cIs 0.95; charging time T at the ith time_iSet to 1 minute with no change in all parameters within 1 minute; the total charging time interval number n is 1; full regulation bus voltage V_BUSIs 29V; i.e. i₀Time of day battery voltage V_BATIs 28V, at i₀The capacity of the storage battery at the moment is 105Ah, the voltage of the storage battery can be determined according to the capacity of the storage battery, the voltage can be determined by looking up a storage battery parameter table, the voltage is obtained by adopting a table look-up mode in the calculation, and the corresponding relation between the voltage of the storage battery and the capacity of the storage battery is shown in figure 2; nominal voltage V of accumulator_BAT0Is 28.7V; equivalent internal resistance R of storage battery_BATThe internal resistance of the storage battery is 0.05 omega, and is obtained through experimental measurement. The calculated battery charge capacity is:

$\begin{array}{c}{C}_c=\underset{i=1}{\overset{n}{\&Sigma;}}{I}_{ci}\&CenterDot;{\mathrm{\&eta;}}_c\&CenterDot;T_i=\underset{i=1}{\overset{n}{\&Sigma;}}min(\frac{P_{QS}-P_{QL}}{V_{BUS}}+\frac{P_{BS}-P_{BL}}{V_{BAT}},\frac{V_{BAT0}-V_{BAT}}{R_{BAT}})\&CenterDot;{\mathrm{\&eta;}}_c\&CenterDot;T_i(P_{QS}-P_{QL}\&GreaterEqual;0,P_{QS}-P_{QL}+P_{BS}-P_{BL}\&GreaterEqual;0)\\ =\min (\frac{467.78-436.6}{29}+\frac{1427.97-842.88}{28},\frac{28.7-28}{0.05})\&times;0.95\&times;1/60=\min (21.97,14)\&times;0.95\&times;1/60=0.22Ah\end{array}$

wherein min (21.97,14) is used as trickle charge criterion,the storage battery adopts trickle charging mode, and the charging current of the storage battery is

The fifth step: and evaluating the energy balance state of the storage battery according to the initial capacity of the storage battery, the current capacity of the storage battery and the total capacity of the storage battery.

If C₀-C_d+C_cIf the carbon content is more than or equal to C, the energy is balanced; if C₀-C_d+C_cIf < C, the energy is not balanced.

Wherein: c₀Is the initial state capacity of the storage battery; and C is the total capacity of the storage battery.

i₀At the moment of one minute, C₀-C_d+C_c＝105-0+0.22＝105.22<120 so the battery is not balanced at this time.

Those skilled in the art will appreciate that the details not described in the present specification are well known.

Claims (7)

1. A spacecraft double-bus energy balance analysis method is characterized by comprising the following steps: the method comprises the following steps:

the first step is as follows: calculating the output power of the solar wing by measuring the solar incident angle and the shielding area of the solar cell array;

the second step is that: calculating the power required by the load by measuring the percentage of the loss power of the cable to the total power of the electric equipment;

the third step: determining the working state of the storage battery by calculating the difference value between the output power of the solar wing and the required power of the load;

the fourth step: judging the charging form of the storage battery, and determining the current capacity of the storage battery by calculating the charging current and the discharging current;

the fifth step: and evaluating the energy balance state of the storage battery according to the initial capacity of the storage battery, the current capacity of the storage battery and the total capacity of the storage battery.

2. The spacecraft double-busbar energy balance analysis method according to claim 1, characterized in that: the criterion for evaluating the energy balance state of the storage battery is as follows: if C₀-C_d+C_cIf the carbon content is more than or equal to C, the energy is balanced; if C₀-C_d+C_cIf < C, the energy is unbalanced;

wherein: c₀Is the initial state capacity of the storage battery; c_dThe discharge capacity of the storage battery is shown; c_cCharging capacity for the battery; and C is the total capacity of the storage battery.

3. A spacecraft double busbar energy balance analysis method according to claim 1 or 2, characterized in that: the solar wing output power comprises full regulation solar wing output power P_QSWithout adjusting the output power P of the solar wing_BS。

4. The spacecraft double-busbar energy balance analysis method according to claim 3, wherein: the load demand power comprises full regulation of bus load demand power and no regulation of bus load demand power;

the calculation formula of the total regulated bus load required power is P_QL＝(1-η_QL)P_Q0；

Wherein: p_QLTo fully regulate the bus load demand power, η_QLFor fully regulating the loss power ratio, P, of the busbar cable_Q0The total power of the bus electric equipment is fully adjusted;

the calculation formula of the demand power of the unregulated bus load is P_BL＝(1-η_BL)P_B0；

Wherein: p_BLTo be irregularSection bus load demand power, η_BLTo not adjust the loss power ratio of the bus cable, P_B0The total power of the bus electric equipment is not regulated.

5. The spacecraft double-busbar energy balance analysis method according to claim 4, wherein: the working state of the storage battery comprises a charging state and a discharging state, and in a double-bus system, a full-regulation bus and a non-regulation bus supply power in a crossed manner;

when P is present_QS－P_QLWhen the current value is more than or equal to 0, the working state of the storage battery is determined by the following formula:

if (P)_QS-P_QL)+P_BS-P_BLIf the charging voltage is more than or equal to 0, the storage battery is in a charging state;

if (P)_QS-P_QL)+P_BS-P_BL<0, the storage battery is in a discharging state;

when P is present_QS－P_QLWhen < 0, the operating state of the battery is determined by the following formula:

if it isThe storage battery is in a charging state;

if it isThe storage battery is in a discharging state;

in the formula η_dThe discharge regulator works efficiently.

6. The spacecraft double-busbar energy balance analysis method according to claim 4, wherein: the current capacity of the battery comprises a battery charge capacity C_cAnd battery discharge capacity C_d；

When P is present_QS-P_QL≥0，P_QS-P_QL+P_BS-P_BLWhen the content is more than or equal to 0,

$C_c=\underset{i=1}{\overset{n}{\&Sigma;}}{I}_{ci}\&CenterDot;{\mathrm{\&eta;}}_c\&CenterDot;T_i=\underset{i=1}{\overset{n}{\&Sigma;}}\min \left(\frac{P_{QS}-P_{QL}}{V_{BUS}}+\frac{P_{BS}-P_{BL}}{V_{BAT}},\frac{V_{BAT0}-V_{BAT}}{R_{BAT}}\right)\&CenterDot;{\mathrm{\&eta;}}_c\&CenterDot;T_i;$

when in useWhen the temperature of the water is higher than the set temperature,

$C_c=\underset{i=1}{\overset{n}{\&Sigma;}}{I}_{ci}\&CenterDot;{\mathrm{\&eta;}}_c\&CenterDot;T_i=\underset{i=1}{\overset{n}{\&Sigma;}}\min \left(\frac{P_{QS}-P_{QL}}{V_{BUS}{\mathrm{\&eta;}}_d}+\frac{P_{BS}-P_{BL}}{V_{BAT}},\frac{V_{BAT0}-V_{BAT}}{R_{BAT}}\right)\&CenterDot;{\mathrm{\&eta;}}_c\&CenterDot;T_i;$

wherein,can be used for judging whether trickle charge is needed or not whenAt the moment, the storage battery adopts a trickle charge mode, and the charging current of the storage battery is

Wherein, I_ciCharging current at time i η_cTo the charging efficiency; t is_iThe charging time at the ith moment; n is the total charging time period number; v_BUSTo fully regulate the bus voltage; v_BATThe voltage of the storage battery is not adjusted; v_BAT0Is the nominal voltage of the storage battery; r_BATThe equivalent internal resistance of the storage battery.

7. The spacecraft double-busbar energy balance analysis method according to claim 6, wherein: the discharge capacity C of the storage battery_dDetermined by the discharge current and the discharge efficiency of the battery:

when P is present_QS-P_QL≥0，P_QS-P_QL+P_BS-P_BLWhen the ratio is less than 0, the reaction mixture is,

$C_d=\underset{i=1}{\overset{n}{\&Sigma;}}{I}_{fi}/{\mathrm{\&eta;}}_d\&CenterDot;\mathrm{\&Delta;}T=\underset{i=1}{\overset{n}{\&Sigma;}}|\frac{P_{QS}-P_{QL}}{V_{BUS}}+\frac{P_{BS}-P_{BL}}{V_{BAT}}|/{\mathrm{\&eta;}}_d\&CenterDot;\mathrm{\&Delta;}T;$

when in useWhen the temperature of the water is higher than the set temperature,

$C_d=\underset{i=1}{\overset{n}{\&Sigma;}}{I}_{fi}/{\mathrm{\&eta;}}_d\&CenterDot;\mathrm{\&Delta;}T=\underset{i=1}{\overset{n}{\&Sigma;}}|\frac{P_{QS}-P_{QL}}{V_{BUS}}+\frac{P_{BS}-P_{BL}}{V_{BAT}}|/{\mathrm{\&eta;}}_d\&CenterDot;\mathrm{\&Delta;}T;$

wherein, I_fiDischarge current at time i η_dTo discharge efficiency; and delta T is the discharge time of the storage battery.