CN102928714A - Moonlet sun array life forecast method based on I-V curve and energy balance - Google Patents

Abstract

The invention provides a moonlet sun array life forecast method based on I-V curve and energy balance. Aiming at the problems that the existing moonlet sun array life forecast method has few damage regularity space environment influencing factors, is limited in life forecast of unit cells to the large extent, cannot forecast the whole life of a sun array, and the like, the moonlet sun array life forecast method is based on space environment simulation tests, and a sun array integral life forecast module is provided taking important space environment factor influence including sun and earth distance factors, track earth shadow time, included angles of sun rays and sun array normals, temperature and sun radiation into account, further the problem of generality of life forecast taking the sun array important life influence factors into account and sun array integral life forecasting suitable for different bathes and different types is solved. The I-V curve is a current and voltage curve of a solar unit cell. The moonlet sun array life forecast method is based on tests, and has good model generality and strong engineering practical applicability.

Description

A kind of moonlet sun battle array life-span prediction method based on I-V curve and energy equilibrium

Technical field

The invention belongs to moonlet sun battle array electric powder prediction, be specifically related to a kind of moonlet sun battle array life-span prediction method based on I-V curve and energy equilibrium.

Background technology

Moonlet is applied to all space fields except manned space flight, is included in remote sensing, communication, navigation, technical identification, space science etc. and has brought into play important effect.Power-supply system is the key service system of satellite, be responsible for to produce, storage and for the whole life period of satellite provides the stable continual energy for whole star with electric loading, its power supply capacity, power supply quality directly affect duty, reliability and the serviceable life of satellite.Performance, reliability to power-supply system control have very high requirement.

Because different satellite transit tracks have its obvious environmental quality, cause the satellite system performance degradation rule and characteristic of different orbital motions to be distinguished to some extent.The orbit major part of moonlet is middle low orbit, affected by complex space environment, as: solar pressure, ionosphere, charged particle etc., the variation range of solar incident angle in 1 year is large, and moonlet turnover shadow is frequent, high and low temperature alternative conversion etc., sun battle array intermittent work often, working time is short, and working current is large, and high/low-temperature impact is violent.These factors inevitably will exert an influence to performance and the life-span of satellite.Final under the combined action of inside and outside factor, cause thrashing.Fig. 1 has provided, owing to each subsystem failure of moonlet causes the shared ratio situation of moonlet global failure.Hence one can see that, and power-supply system lost efficacy and occupies most of ratio, and the inefficacy of sun battle array is the main factor that power-supply system lost efficacy.

Yet, because moonlet belongs to non-repairable item, and be subjected to the restriction of quality and size, the method that can not take redundant component to be improving the reliability of moonlet sun battle array, so that the life prediction of moonlet sun battle array plays the important guiding effect for design, production, the use of moonlet.

The method that is applied at present moonlet sun battle array life prediction under the space environment condition can be summarized as: (one), ultraviolet acceleration lifetime test method: set up the ultraviolet acceleration lifetime test device under the space environmental simulation, solar cell is carried out the ultraviolet acceleration lifetime test technical research, obtain the delta data of solar batteries along with the ultraviolet irradiation time.By experimental data processing, the acquisition solar batteries adopts to add severe judgement according to theory along with the attenuation law of equivalent ultraviolet irradiation time, and the research UV radiation is predicted the battery life under the ultraviolet irradiation environment to the injuring rule of solar cell; (2), thermal strain extremum method: the thermal strain development law of solar panel after the thermal cycle repeatedly take experimental test as fundamental analysis, proposition as the Damage Parameter of multi-layer bonded joint structure, is set up the methods such as mathematical model in pre-shoot the sun monomer battery structure life-span with thermal strain maximum value (or residual heat strain).Wherein, the ultraviolet acceleration lifetime test method has only been considered this space environment condition of ultraviolet, and than other life-span influence factor, a little less than the impact relatively of ultraviolet, singlely carry out UV radiation research can not well disclose the injuring rule of sun battle array under the complex space environment condition to the injuring rule of sun battle array; The thermal strain extremum method is from having set up the data model of cell by test, for through experimental test, and only consider that the life prediction of cell under temperature effect is effective, Life Prediction Model need to be rebulid for sun monomers such as different batches, different models, and sun battle array bulk life time forecasting problem can't be solved.

Summary of the invention

Problem for current moonlet sun battle array life prediction existence, the present invention proposes a kind of moonlet sun battle array life-span prediction method based on I-V curve and energy equilibrium, on the basis of space environment simulation test, be structured in the sun battle array bulk life time forecast model under the important space such environmental effects such as the angle of considering the solar distance factor, track ecliptic time, sunray and sun tactical deployment of troops line, temperature, solar radiation, and then part solves the versatility problem that the life prediction of considering the important life-span influence factor of sun battle array and sun battle array bulk life time are predicted.Electric current and voltage curve that described I-V curve is sun cell.

The technical solution used in the present invention is: a kind of moonlet sun battle array life-span prediction method based on I-V curve and energy equilibrium, and the method realizes as follows:

The angle of step 1, the solar distance factor, track ecliptic time, sunray and sun tactical deployment of troops line is determined;

According to orbit altitude, southbound node local time and prediction zero-time, calculate the Changing Pattern of angle of the solar distance factor, orbital period Te, track ecliptic time, every rail sunray and the sun tactical deployment of troops line of every day, obtain time dependent quantitative data, be used for follow-up sun battle array I-V curve and Energy Balance Analysis;

Step 2, sun battle array I-V curve model are determined;

Make up sun battle array computation model according to sun battle array characteristic, consider simultaneously the impact of solar incident angle, irradiation decay, day ground factor, loss factor factor, calculate sun battle array output voltage, output current under Various Seasonal, different track condition and the different operating modes, reach in real time the secular variation situation to characterize sun battle array output power;

Take the I-V curvilinear characteristic point of standard state as parameter, consider that multiple environmental factor on the impact in sun battle array life-span, calculates the output characteristics of sun battle array; Utilize the computer analyzing model of formula (Equ.1) sun battle array I-V curve, obtain the I-V family curve of the sun battle array under the different condition; This model during less than 2 solar constants, has very high accuracy in intensity of illumination; The light conditions of sun synchronous orbit moonlet satisfies this condition:

$\left\{\begin{array}{c}I={\mathrm{Isc}}^{\&prime;}(1-{\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HDA00002350390600011.png,HDA00002350390600022.png"\; state="\{\{state\}\}">C</figure-callout>}}_1\&times;\{\exp [V/({\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HDA00002350390600022.png"\; state="\{\{state\}\}">C</figure-callout>}}_2\&times;V_{\mathrm{ov}}\&prime;)]-1\left\}\right)\\ {\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HDA00002350390600011.png,HDA00002350390600022.png"\; state="\{\{state\}\}">C</figure-callout>}}_1=[1-({I_{\mathrm{mp}}}^{\&prime;}/{\mathrm{Isc}}^{\&prime;})]\&times;\left\{\exp \right[-{V_{\mathrm{mp}}}^{\&prime;}/({\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HDA00002350390600022.png"\; state="\{\{state\}\}">C</figure-callout>}}_2\&times;{V_{\mathrm{ov}}}^{\&prime;}){]}^{}\}\\ {\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HDA00002350390600022.png"\; state="\{\{state\}\}">C</figure-callout>}}_2=[({V_{\mathrm{mp}}}^{\&prime;}/{V_{\mathrm{ov}}}^{\&prime;})-1]/1n(1-{I_{\mathrm{mp}}}^{\&prime;}/{\mathrm{Isc}}^{\&prime;})\end{array}\right.---(\mathrm{Equ}.1)$

In the formula:

I---output current, unit are A;

Isc'---sun battle array short-circuit current, canonical parameter or measured value, unit are A;

C ₁---formula coefficient 1;

V---sun battle array output voltage, unit are V;

C ₂---formula coefficient 2;

V _Ov'---sun battle array open-circuit voltage, canonical parameter or measured value, unit are V;

I _Mp'---sun battle array best operating point output current, canonical parameter or measured value, unit are A;

V _Mp'---sun battle array best operating point output voltage, canonical parameter or measured value, unit are V;

Sun battle array open-circuit voltage and best operating point output voltage computation model are as follows:

$\left\{\begin{array}{c}{V}_{\mathrm{ov}}\&prime;=(V_{\mathrm{ov}}+{\mathrm{\&beta;}}_{\mathrm{VBOL}}\&times;(T-25))\&times;0.98\&times;0.98\&times;N_s\&times;K_{\mathrm{VRAD}}\\ V_{\mathrm{mp}}\&prime;=(V_{\mathrm{mp}}+{\mathrm{\&beta;}}_{\mathrm{VBOL}}\&times;(T-25))\&times;0.98\&times;0.98\&times;N_s\&times;K_{\mathrm{VRAD}}\end{array}\right.---(\mathrm{Equ}.2)$

In the formula:

V _Ov---single solar cell open-circuit voltage, unit are V;

V _Mp---single solar cell best effort point voltage, unit are V;

β _VBOL---single solar cell beginning of lifetime voltage temperature coefficient, unit are V/ ℃;

K _VRAD---sun battle array open-circuit voltage irradiation declines and falls the factor;

T---sun battle array temperature, unit is ℃;

Sun battle array short-circuit current and best operating point Current calculation model are as follows:

$\left\{\begin{array}{c}\mathrm{Isc}\&prime;=({\mathrm{Isc}}_{}+{\mathrm{\&alpha;}}_I\&times;(T-25))\&times;0.98\&times;0.98\&times;0.98{\&times;N}_p\&times;\cos \mathrm{\&theta;}\left(t\right)\&times;F_{\mathrm{rd}}\&times;K_{\mathrm{IRAD}}\\ I_{\mathrm{mp}}\&prime;=(I_{\mathrm{mp}}+{\mathrm{\&alpha;}}_I\&times;(T-25))\&times;0.98\&times;0.98\&times;0.98\&times;N_p\&times;\cos \mathrm{\&theta;}\left(t\right)\&times;F_{\mathrm{rd}}\&times;K_{\mathrm{IRAD}}\end{array}\right.---(\mathrm{Equ}.3)$

I _SC---single solar cell short-circuit current, unit are A;

I _Mp---single solar cell best operating point electric current, unit are A;

α _I-single solar cell current temperature coefficient, unit are A/ ℃;

θ (t)---the angle of sunray and sun tactical deployment of troops line direction in the circle track, unit is degree;

T-sun battle array temperature, unit are ℃;

K _IRAD-sun battle array short-circuit current irradiation declines and falls the factor;

F _Rd---the solar distance factor;

Utilize " sun battle array open-circuit voltage and short-circuit current irradiation decline and falls factor computation model " prediction LEO track radiation environment on the impact of satellite solar cell output parameter decay, Isc is K in this model _IRAD, Vov is K _VRAD

A. the mode input parameter-definition is as follows:

Battery types: unijunction GaAs solar cell; Quartz glass coverslip thickness: 120 μ m; Orbit altitude: 300km ~ 3000km; Inclination angle: only for 99 °; Chronomere: month;

B. the model output parameter is defined as follows:

Peak power output P _Max, short-circuit current I _Sc, open-circuit voltage V _Ov, its output form: provide P _Max, I _ScAnd V _OvAfter m month, P _Max, I _ScAnd V _OvBe the number percent of initial value, namely provide P _Max, I _ScAnd V _OvFunction about time month;

For this sun battle array open-circuit voltage and short-circuit current irradiation decline the computation model of the factor falls below:

The multiple orbital attitudes displacement damage dose is calculated as follows: x is orbit altitude, and month is at rail moon number, and y is the displacement damage dose that calculates;

When 300km＜=x＜=600km, computing formula is:

y＝14（A ₀+A ₁·x+A ₂·x ²+A ₃·x ³+A ₄·x ⁴+A ₅·x ⁵）·month （Equ.4）

Wherein, A0=-5.72637E6, A1=69074.68933, A2=-329.19032,

A3=0.77634，A4=-9.13546E-4，A5=4.49106E-7

When 600km＜x＜=1000km, computing formula is:

y＝14（A ₀+A ₁·x+A ₂·x ²+A ₃·x ³+A ₄·x ⁴）·month （Equ.5）

Wherein, A0=-5.80893E7, A1=321272.30685, A2=-663.23216, A3=0.59526, A4=-1.77968E-4 is when 1000km＜x＜=3000km, and computing formula is:

y＝14（A ₀+A ₁·x+A ₂·x ²+A ₃·x ³+A ₄·x ⁴+A ₅·x ⁵）·month （Equ.6）

Wherein, A0=5.01219E8, A1=-1.76649E6, A2=2453.54778,

A3=-1.65135，A4=5.32602E-4，A5=-5.18233E-8

The computation model of the Pmax of GaAs/Ge solar cell, Isc and Voc is:

Peak power output decay, the i.e. computation model of Pmax:

P _max=1.0-C×log10(1+(y/Dx)) （Equ.7）

Wherein, C=0.242, Dx=3.47e9, y are the displacement damage dose that calculates;

Short-circuit current decay, the i.e. computation model of Isc:

K _IRAD=Isc=1.0-C×log10(1+(y/Dx)) （Equ.8）

Wherein, C=0.213, Dx=8.3e19

Open-circuit voltage decay, the i.e. computation model of Voc:

K _VRAD=Vov=1.0-C×log10(1+(y/Dx)) （Equ.9）

Wherein, C=0.07, Dx=1.8e9

Step 3, sun battle array energy equilibrium computation model are determined;

Carry out energy equilibrium when calculating, according to the data that provide on rail data or ground the critical conditions of energy equilibrium is being carried out Real Time Monitoring, if sun battle array provides the unnecessary electric weight Q of energy _Residual(c) by on the occasion of changing zero into, show that then sun battle array has been in the major injury state, and Q _Residual(c) calculating formula is:

$Q_{\mathrm{residual}}\left(c\right)=I_{\mathrm{SA}}\left(c\right)\&times;(\mathrm{Te}-\mathrm{te})-I_{\mathrm{load}\_\mathrm{mean}}\left(c\right)\&times;(\mathrm{Te}-\mathrm{te})-1.02\&times;{\&Integral;}_0^{\mathrm{te}}{I}_d\left(t\right)\&times;\mathrm{dt}---(\mathrm{Equ}.10)$

Wherein:

Q _Residual(c)---at the available unnecessary electric weight of rail c circle sun battle array, unit is C;

Te---time shade phase, unit is s;

I _SA(c)---at rail c circle square formation current clamp point current value, unit is A;

I _{Load_mean}(c)---illumination period load current I _Load(A), it is that unit is A at the rail c mean value in circle per cycle of load current;

I _d(t)---the shade phase, battery discharging electric current, unit are A;

According to the equation of designated period of time sun battle array I-V curve, providing corresponding area of illumination busbar voltage V _{S_bus}And sun battle array isolating diode and power cable pressure drop sum V _{S_dioline}The time, obtain sun battle array operating voltage clamped point V on this designated period of time I-V curve _Op1The current value I at place _{S_op1}Calculated as can be known by energy equilibrium, the sun battle array of this designated period of time provides the unnecessary electric weight Q of energy _Residual(c) can be expressed as:

$Q_{s-\mathrm{residual}}\left(c\right)=I_{s\_\mathrm{opl}}\left(c\right)\&times;(\mathrm{Te}-\mathrm{te})-I_{s\_\mathrm{load}\_\mathrm{mean}}\left(c\right)\&times;(\mathrm{Te}-\mathrm{te})-1.02\&times;{\&Integral;}_0^{\mathrm{te}}{I}_d\left(t\right)\&times;\mathrm{dt}---(\mathrm{Equ}.11)$

In the formula:

I _{S_op1}---give directions sun battle array operating voltage clamped point V on the I-V curve in period _Op1The current value at place, unit is A;

I _{S_load_mean}---designated period of time area of illumination load current/at the mean value of all load current data of rail, unit is A;

I _d(t)---the designated period accumulator is at the discharge current value in shadow region, and unit is A;

Sun battle array operating voltage point output power computation model is as follows;

P _sA(t)＝V _bus(t)Iop1(t)， I _sa(t)＝I _op1(t)

Further can get:

P _{s_op1}(c)＝V _{s_bus}(c)I _{s_op1}(c)

V _{s_op1}(c)＝V _{s_bus}(c)+V _{s_dioline} （Equ.12）

In the formula:

Constantly, from 0＜t＜Te, wherein, Te is the orbital period to t--c in the circle orbital period, and unit is s;

P _SA---sun battle array output power, unit is W;

P _{S_op1}(c)---c circle sun battle array is output as clamped point V _{S_op1}The time output power, unit is W;

I _{S_op1}(c)---sun battle array operating voltage clamped point V on the c circle I-V curve _{S_op1}The time current value, unit is A;

V _{S_bus}---the area of illumination busbar voltage, unit is V;

V _{S_dioline}---sun battle array isolating diode and power cable pressure drop sum, unit is V;

For in the rail power-supply system, because power-supply controller of electric is so that the illumination period busbar voltage remains definite value, thereby can think: under the prerequisite of power-supply controller of electric normal operation, the illumination period busbar voltage is constant all the time; Simultaneously, obtaining V _{S_dioline}After the value, can be enough I-V curve by above-mentioned foundation obtain designated period of time clamped point current value I _{S_op}(c), calculate to be used for energy equilibrium;

If system prediction obtains certain designated period of time Q _Residual(c)=0, illustrate that then sun battle array is to the longevity at this moment;

Wherein, when carrying out the calculating of battery pack discharge current, the discharge current of battery pack depends on the discharge power of battery pack, discharge regulator efficiency, battery pack supply line dissipation factor, battery voltage factor;

The shadow region, the battery pack discharge current is:

$I_d\left(t\right)=\frac{(I_{\mathrm{load}}\left(t\right)-I_{\mathrm{SA}}\left(t\right))\&times;V_{\mathrm{bus}}}{{\mathrm{\&eta;}}_{\mathrm{BDR}}\&CenterDot;{\mathrm{\&eta;}}_{\mathrm{line}}\&CenterDot;V_{\mathrm{bat}}\left(t\right)}$

In the formula:

Constantly, from 0＜t＜Te, wherein, Te is the orbital period to t--c in the circle orbital period, and unit is s;

I _Load(t)--at the time dependent function of rail load current demand; η _BDR--the discharge regulator efficiency;

n _Ine--battery pack supply line dissipation factor;

V _Bat(t)--the battery pack sparking voltage; Based in the battery discharging first pressing of rail c circle track and discharge final pressure value, can think approx V _Bat(t) just be depressed into discharge final pressure linear change by discharge;

V _Bus: busbar voltage during discharge, unit is V;

Wherein: shadow region sun battle array I _SA(t) electric current is zero, V _Bat(t) be an integrand, this function is at rail discharge first pressing and the definite linear function of discharge final pressure by accumulator.

Wherein, described sun battle array temperature is calculated as follows by sun battle array temperature model:

Sun battle array temperature changes with the variation of satellite turnover shadow state, the shadow zone, ground, and sun battle array temperature descends gradually, until be down to out the minimum temperature before the shadow; Illumination period, sun battle array temperature rises rapidly from going out the movie queen, until reach photoperiodic equalized temperature point, after this temperature remains unchanged until satellite enters the ground shadow phase of next rail ring, goes round and begins again;

The simplified model of sun battle array temperature variation is as follows:

Within the ground shadow phase, sun battle array temperature drops to ground shadow phase minimum temperature from the highest photoperiodic equilibrium temperature linearity, goes out the movie queen, and sun battle array temperature rose to 60 ℃ from ground shadow phase minimum temperature in 8 minutes, in 20 minutes, rise to the highest equilibrium temperature of illumination period from 60 ℃, until advance shadow next time;

The highest photoperiodic equilibrium temperature, the default value of shadow phase minimum temperature be respectively:

The highest photoperiodic equilibrium temperature T _SASGround shadow phase minimum temperature T _SAE

Advantage of the present invention is:

(1), influence factor of many life-spans is comprehensive: the present invention is take test as the basis, considers the sun battle array bulk life time forecast model under the important space such environmental effects such as angle, temperature, solar radiation of the solar distance factor, track ecliptic time, sunray and sun tactical deployment of troops line;

(2), model commonality: for sun synchronous orbit moonlet sun battle array, comprising: the bulk life time prediction of Si and all types of solar battery arrays of GaAs, the limitation of having avoided to carry out the specific monomer battery life prediction;

(3), engineering practicability: the application's sun battle array life-span prediction method belongs to the method that physical model combines with data-driven.In modeling process, taked the part simplified way, simultaneously, the needed data of model are obtained easily based on the parameter that existing moonlet gathers, simplify the problems such as the complexity of Life Prediction Model and data acquisition difficulty, and then had stronger engineering practicability.

Description of drawings

Fig. 1 causes moonlet failure ratio row relations of distribution figure for each subsystem failure;

Fig. 2 is sun battle array life prediction process flow diagram;

Fig. 3 is moonlet solar cell characteristic parameter decay calculation flow chart;

Fig. 4 is sun battle array year solar distance factor variations law curve figure;

Fig. 5 is solar incident angle year Changing Pattern curve map;

Fig. 6 is HY-1B moonlet sun battle array I-V curve map;

Fig. 7 provides unnecessary electric weight temporal evolution curve map for sun battle array.

Embodiment

The present invention is described in detail below in conjunction with drawings and Examples.

A kind of moonlet sun battle array life-span prediction method based on I-V curve and energy equilibrium, the method realizes as follows:

The angle of step 1, the solar distance factor, track ecliptic time, sunray and sun tactical deployment of troops line is determined;

According to orbit altitude, southbound node local time and prediction zero-time, call STK software, calculate the Changing Pattern of angle of the solar distance factor, orbital period Te, track ecliptic time, every rail sunray and the sun tactical deployment of troops line of every day, obtain time dependent quantitative data, be used for follow-up sun battle array I-V curve and Energy Balance Analysis.

Step 2, sun battle array I-V curve model are determined;

Make up sun battle array computation model according to sun battle array characteristic, consider simultaneously the impact of the factors such as solar incident angle, irradiation decay, day ground factor, loss factor, calculate sun battle array output voltage, output current under Various Seasonal, different track condition and the different operating modes, reach in real time the secular variation situation to characterize sun battle array output power.

Take the I-V curvilinear characteristic point of standard state as parameter, consider that multiple environmental factor on the impact in sun battle array life-span, calculates the output characteristics of sun battle array.Utilize the computer analyzing model of Equ.1 sun battle array I-V curve, can obtain the I-V family curve of the sun battle array under the different condition.This model during less than 2 solar constants, has very high accuracy in intensity of illumination.The light conditions of sun synchronous orbit moonlet satisfies this condition:

$\left\{\begin{array}{c}I={\mathrm{Isc}}^{\&prime;}(1-{\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HDA00002350390600011.png,HDA00002350390600022.png"\; state="\{\{state\}\}">C</figure-callout>}}_1\&times;\{\exp [V/({\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HDA00002350390600022.png"\; state="\{\{state\}\}">C</figure-callout>}}_2\&times;V_{\mathrm{ov}}\&prime;)]-1\left\}\right)\\ {\mathrm{<figure-callout\; id="1"\; label="C"\; filenames="HDA00002350390600011.png,HDA00002350390600022.png"\; state="\{\{state\}\}">C</figure-callout>}}_1=[1-({I_{\mathrm{mp}}}^{\&prime;}/{\mathrm{Isc}}^{\&prime;})]\&times;\left\{\exp \right[-{V_{\mathrm{mp}}}^{\&prime;}/({\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HDA00002350390600022.png"\; state="\{\{state\}\}">C</figure-callout>}}_2\&times;{V_{\mathrm{ov}}}^{\&prime;}){]}^{}\}\\ {\mathrm{<figure-callout\; id="2"\; label="C"\; filenames="HDA00002350390600022.png"\; state="\{\{state\}\}">C</figure-callout>}}_2=[({V_{\mathrm{mp}}}^{\&prime;}/{V_{\mathrm{ov}}}^{\&prime;})-1]/1n(1-{I_{\mathrm{mp}}}^{\&prime;}/{\mathrm{Isc}}^{\&prime;})\end{array}\right.---(\mathrm{Equ}.1)$

In the formula:

I---sun battle array output current, unit are A;

ISC '---sun battle array short-circuit current, canonical parameter or measured value, unit are A;

C ₁---formula coefficient 1;

V---sun battle array output voltage, unit are V;

C ₂---formula coefficient 2;

V _Ov' _ _ _ _ _ the battle array open-circuit voltage, canonical parameter or measured value, unit are V;

I _Mp'---sun battle array best operating point output current, canonical parameter or measured value, unit are A;

V _Mp'---sun battle array best operating point output voltage, canonical parameter or measured value, unit are V.

(1) sun battle array characteristic feature point calculation of parameter model;

(1.1) sun battle array open-circuit voltage and best operating point output voltage:

$\left\{\begin{array}{c}{V}_{\mathrm{ov}}\&prime;=(V_{\mathrm{ov}}+{\mathrm{\&beta;}}_{\mathrm{VBOL}}\&times;(T-25))\&times;0.98\&times;0.98\&times;N_s\&times;K_{\mathrm{VRAD}}\\ V_{\mathrm{mp}}\&prime;=(V_{\mathrm{mp}}+{\mathrm{\&beta;}}_{\mathrm{VBOL}}\&times;(T-25))\&times;0.98\&times;0.98\&times;N_s\&times;K_{\mathrm{VRAD}}\end{array}\right.---(\mathrm{Equ}.2)$

In the formula:

V _Ov---single solar cell open-circuit voltage (AM0 of QJ 1019-1995 regulation, 25 ℃), unit is V;

V _Mp---single solar cell best effort point voltage (AM0 of QJ 1019-1995 regulation, 25 ℃), unit is V;

β _VBOL---single solar cell beginning of lifetime voltage temperature coefficient (temperature change of solar cell 1 ℃ time, the changing value of its output voltage), unit is V/ ℃;

K _VRAD---sun battle array open-circuit voltage irradiation declines and falls the factor;

T---sun battle array temperature, unit is ℃.

(1.2) sun battle array short-circuit current and best operating point Current calculation model:

$\left\{\begin{array}{c}\mathrm{Isc}\&prime;=({\mathrm{Isc}}_{}+{\mathrm{\&alpha;}}_I\&times;(T-25))\&times;0.98\&times;0.98\&times;0.98{\&times;N}_p\&times;\cos \mathrm{\&theta;}\left(t\right)\&times;F_{\mathrm{rd}}\&times;K_{\mathrm{IRAD}}\\ I_{\mathrm{mp}}\&prime;=(I_{\mathrm{mp}}+{\mathrm{\&alpha;}}_I\&times;(T-25))\&times;0.98\&times;0.98\&times;0.98\&times;N_p\&times;\cos \mathrm{\&theta;}\left(t\right)\&times;F_{\mathrm{rd}}\&times;K_{\mathrm{IRAD}}\end{array}\right.---(\mathrm{Equ}.3)$

I _SC---single solar cell short-circuit current (AM025 ℃ of condition of QJ 1019-1995 regulation), unit is A;

I _Mp---single solar cell best operating point electric current (AM0 of QJ 1019-1995 regulation, 25 ℃ of conditions), unit is A;

α _I---single solar cell current temperature coefficient (temperature change of solar cell 1 ℃ time, the changing value of its output current), unit is A/ ℃;

θ (t)---the angle of sunray and sun tactical deployment of troops line direction in the circle track, unit is degree;

T---sun battle array temperature, unit is ℃;

K _IRAD---sun battle array short-circuit current irradiation declines and falls the factor;

F _Rd---the solar distance factor.

(2) sun battle array open-circuit voltage and short-circuit current irradiation decline and fall factor computation model;

This model is used for prediction LEO track radiation environment to the impact of satellite solar cell output parameter decay, and Isc is K in the model _IRAD, Vov is K _VRAD

A. the mode input parameter-definition is as follows:

Battery types: unijunction GaAs solar cell; Quartz glass coverslip thickness: 120 μ m; Orbit altitude: 300km ~ 3000km; Inclination angle: only for 99 °; Chronomere: month;

B. the model output parameter is defined as follows:

Peak power output P _Max, short-circuit current I _Sc, open-circuit voltage V _Ov(output form: provide P _Max, I _ScAnd V _OvAfter m month, P _Max, I _ScAnd V _OvBe the number percent of initial value, namely provide P _Max, I _ScAnd V _OvFunction about time month);

Below be the calculating formula of this computation model:

(2.1) the multiple orbital attitudes displacement damage dose calculates

X is orbit altitude, and month is at rail moon number, and y is the displacement damage dose (proton displacement damage dose) that calculates.

When 300km＜=x＜=600km, computing formula is:

y＝14（A ₀+A ₁·x+A ₂·x ²+A ₃·x ³+A ₄·x ⁴+A ₅·x ⁵）·month （Equ.4）

Wherein, A0=-5.72637E6, A1=69074.68933, A2=-329.19032,

A3=0.77634，A4=-9.13546E-4，A5=4.49106E-7

When 600km＜x＜=1000km, computing formula is:

y＝14（A ₀+A ₁·x+A ₂·x ²+A ₃·x ³+A ₄·x ⁴）·month （Equ.5）

Wherein, A0=-5.80893E7, A1=321272.30685, A2=-663.23216, A3=0.59526, A4=-1.77968E-4 is when 1000km＜x＜=3000km, and computing formula is:

y＝14（A ₀+A ₁·x+A ₂·x ²+A ₃·x ³A ₄·x ⁴+A ₅·x ⁵）·month （Equ.6）

Wherein, A0=5.01219E8, A1=-1.76649E6, A2=2453.54778,

A3=-1.65135，A4=5.32602E-4，A5=-5.18233E-8

(2.2) computation model of the Pmax of GaAs/Ge solar cell, Isc and Voc

Peak power output decay (computation model of Pmax):

P _max=1.0-C×log10(1+(y/Dx)) （Equ.7）

Wherein, C=0.242, Dx=3.47e9, y are the displacement damage dose that calculates.

Short-circuit current decay (computation model of Isc):

K _IRAD=Isc=1.0-C×log10(1+(y/Dx)) （Equ.8）

Wherein, C=0.213, Dx=8.3e19

Open-circuit voltage decay (computation model of Voc):

K _VRAD=Vov=1.0-C×log10(1+(y/Dx)) （Equ.9）

Wherein, C=0.07, Dx=1.8e9

(3) sun battle array temperature model;

Sun battle array temperature changes with the variation of satellite turnover shadow state.The shadow zone, ground, sun battle array temperature descends gradually, until be down to out the minimum temperature before the shadow; Illumination period, sun battle array temperature rises rapidly from going out the movie queen, until reach photoperiodic equalized temperature point, after this temperature remains unchanged until satellite enters the ground shadow phase of next rail ring, goes round and begins again.

The simplified model of sun battle array temperature variation is as follows:

Within the ground shadow phase, sun battle array temperature drops to ground shadow phase minimum temperature from the highest photoperiodic equilibrium temperature linearity, goes out the movie queen, and sun battle array temperature rose to 60 ℃ from ground shadow phase minimum temperature in 8 minutes, in 20 minutes, rise to the highest equilibrium temperature of illumination period from 60 ℃, until advance shadow next time.

The highest photoperiodic equilibrium temperature, the default value of shadow phase minimum temperature be respectively:

The highest photoperiodic equilibrium temperature T _SASGround shadow phase minimum temperature T _SAE

Step 3, sun battle array energy equilibrium computation model;

(1) energy equilibrium is calculated;

According to the data that provide on rail data or ground the critical conditions of energy equilibrium is carried out Real Time Monitoring, if sun battle array provides the unnecessary electric weight Q of energy _Esidual(c) by on the occasion of changing zero into, show that then sun battle array has been in the major injury state, and Q _Esidual(c) calculating formula is:

$Q_{\mathrm{residual}}\left(c\right)=I_{\mathrm{SA}}\left(c\right)\&times;(\mathrm{Te}-\mathrm{te})-I_{\mathrm{load}\_\mathrm{mean}}\left(c\right)\&times;(\mathrm{Te}-\mathrm{te})-1.02\&times;{\&Integral;}_0^{\mathrm{te}}{I}_d\left(t\right)\&times;\mathrm{dt}---(\mathrm{Equ}.10)$

Wherein:

Q _Residual(c)---at the available unnecessary electric weight of rail c circle sun battle array, unit is C;

Te---time shade phase, unit is s;

I _SA(c)---at rail c circle square formation current clamp point current value, unit is A;

I _{Load_mean}(c)---illumination period load current I _Load(A) (at the rail c mean value in circle per cycle of load current), unit is A;

I _d(t)---the shade phase, battery discharging electric current, unit are A;

By ' sun battle array operating voltage point output power computation model ' as can be known, according to the equation of designated period of time sun battle array I-V curve, providing corresponding area of illumination busbar voltage V _{S_bus}And sun battle array isolating diode and power cable pressure drop sum V _{S_dioline}The time, can obtain sun battle array operating voltage clamped point V on this designated period of time I-V curve _Op1The current value I at place _{S_opl}Calculated as can be known by energy equilibrium, the sun battle array of this designated period of time provides the unnecessary electric weight Q of energy _Esidual(c) can be expressed as:

$Q_{s-\mathrm{residual}}\left(c\right)=I_{s\_\mathrm{opl}}\left(c\right)\&times;(\mathrm{Te}-\mathrm{te})-I_{s\_\mathrm{load}\_\mathrm{mean}}\left(c\right)\&times;(\mathrm{Te}-\mathrm{te})-1.02\&times;{\&Integral;}_0^{\mathrm{te}}{I}_d\left(t\right)\&times;\mathrm{dt}---(\mathrm{Equ}.11)$

In the formula:

I _{S_op1}---give directions sun battle array operating voltage clamped point V on the I-V curve in period _Op1The current value at place;

I _{S_load_mean}---designated period of time area of illumination load current/at the mean value of all load current data of rail;

I _d(t)---the designated period accumulator is at the discharge current value in shadow region;

If system prediction obtains certain designated period of time Q _Residual(c)=0, illustrate that then sun battle array is to the longevity at this moment.

(2) sun battle array operating voltage point output power computation model;

P _SA(t)＝V _bus(t)I _op1(t)， I _SA(t)＝I _op1(t)

Further can get:

P _{s_OP1}(c)＝V _{s_bus}(c)I _{s_op1}(c)

V _{s_op1}(c)＝V _{s_bus}(c)+V _{s_dioline} （Equ.12）

In the formula:

Constantly, from 0＜t＜Te(wherein, Te is the orbital period to t--c in the circle orbital period), unit is s;

P _SA---sun battle array output power, unit is W;

P _{S_OP1}(c)---c circle sun battle array is output as clamped point V _{S_op1}The time output power, unit is W;

I _{S_opl}(c)---sun battle array operating voltage clamped point V on the c circle I-V curve _{S_op1}The time current value, unit is A;

V _{S_bus}---the area of illumination busbar voltage, unit is V;

V _{S_dioline}---sun battle array isolating diode and power cable pressure drop sum, unit is V;

For in the rail power-supply system, because power-supply controller of electric is so that the illumination period busbar voltage remains definite value, thereby can think: under the prerequisite of power-supply controller of electric normal operation, the illumination period busbar voltage is constant all the time; Simultaneously, after obtaining the Vs_dioline value, can be enough I-V curve by above-mentioned foundation obtain designated period of time clamped point current value I _{S_op1}(c), calculate to be used for energy equilibrium.

(3) battery discharging Current calculation;

The discharge current of battery pack depends on the discharge power of battery pack, the factors such as regulator efficiency, battery pack supply line dissipation factor, battery voltage of discharging.

The shadow region, the battery pack discharge current is:

$I_d\left(t\right)=\frac{(I_{\mathrm{load}}\left(t\right)-I_{\mathrm{SA}}\left(t\right))\&times;V_{\mathrm{bus}}}{{\mathrm{\&eta;}}_{\mathrm{BDR}}\&CenterDot;{\mathrm{\&eta;}}_{\mathrm{line}}\&CenterDot;V_{\mathrm{bat}}\left(t\right)}$

In the formula:

Constantly, from 0＜t＜Te(wherein, Te is the orbital period to t--c in the circle orbital period), unit is s;

I _Load(t)--at the time dependent function of rail load current demand;

η _BDR--the discharge regulator efficiency

η _Line--battery pack supply line dissipation factor

V _Bat(t)--the battery pack sparking voltage; Based in the battery discharging first pressing of rail c circle track and discharge final pressure value, can think approx V _Bat(t) just be depressed into discharge final pressure linear change by discharge;

V _Bus: busbar voltage during discharge, unit is V;

Wherein: shadow region sun battle array I _SA(t) electric current is zero, V _Bat(t) be an integrand, this function is at rail discharge first pressing and the definite linear function of discharge final pressure by accumulator.This patent is only considered the life prediction problem of sun battle array; suppose that namely all normal or accumulators of accumulator and power-supply controller of electric duty and power-supply controller of electric performance degradation do not exert an influence to sun battle array; thereby accumulator can be processed with definite value in rail discharge first pressing and discharge final pressure herein.

Embodiment 1 is as follows:

The present invention is a kind of moonlet sun battle array life-span prediction method based on I-V curve and energy equilibrium, described life-span prediction method is the degenerative process that sun battle array performance degradation process is considered as energy equilibrium, thereby, having considered under moonlet running space environmental factor (comprising: the angle of the solar distance factor, track ecliptic time, sunray and sun tactical deployment of troops line, temperature, the solar radiation etc.) impact, set up the sun battle array comprehensive life forecast model with better versatility.Figure 2 shows that the overview flow chart of life-span prediction method of the present invention, the implementation step is as follows:

The angle of step 1, the solar distance factor, track ecliptic time, sunray and sun tactical deployment of troops line is determined;

According to orbit altitude, southbound node local time and prediction zero-time, call STK software, calculate the Changing Pattern of the angle of the solar distance factor, orbital period, track ecliptic time, track sunray and sun tactical deployment of troops line, obtain time dependent quantitative data, be used for follow-up sun battle array I-V curve and Energy Balance Analysis.

Step 2, sun battle array I-V curve model;

(1) sun battle array open-circuit voltage and short-circuit current irradiation decline and fall factor computation model;

What Fig. 3 provided is that LEO track radiation environment is to the quantitative calculation process of solar cell characteristic parameter influence of fading.In conjunction with Fig. 3, at first, according to moonlet orbit altitude displacement calculating damage dose over time function y=f (month) (wherein, relevant parameter is referring to Equ.4 ~ Equ.6).

Secondly, utilizing formula Equ.8-9 to calculate respectively sun battle array open-circuit voltage irradiation declines and falls over time function K of the factor _VRAD=gv (month) declines with sun battle array short-circuit current irradiation and falls over time function K of the factor _IRAD=gI (month).

(2) sun battle array characteristic feature point calculation of parameter model;

For computing formula Equ.2-3, wherein, V _Ov, V _Op, β _VBOL, I _SC, I _Mp, α _I, N _pN _sBe all the known parameters data; θ (t), F _RdCalculate by above-mentioned steps; K _IRAD, K _VRADFunction for month; Obtained the temperature data of illumination period sun battle array by sun battle array temperature model.Above-mentioned parameter data and function are brought into Equ.2 can get sun battle array open-circuit voltage and best operating point output voltage, sun battle array short-circuit current and best operating point electric current, can be expressed as follows:

$\left\{\begin{array}{c}{V}_{\mathrm{ov}}\&prime;=V_{\mathrm{ov}}\left(\mathrm{month}\right)\\ V_{\mathrm{mp}}\&prime;=V_{\mathrm{mp}}\left(\mathrm{month}\right)\end{array}\right.$ $\left\{\begin{array}{c}\mathrm{Isc}\&prime;=\mathrm{Isc}\left(\mathrm{month}\right)\\ I_{\mathrm{mp}}\&prime;=I_{\mathrm{mp}}\left(\mathrm{month}\right)\end{array},---(\mathrm{Equ}.14)\right.$

Formula Equ.14 is brought into Equ.1, respectively computing formula coefficient C ₁, C ₂, and then can set up the time dependent rule of sun battle array I-V curve, can be expressed as:

I＝V(month) （Equ.15）

Be open-circuit voltage point (V with three unique points on the I-V curve _Oc'), short-circuit current point (I _SC') and maximum power point (I _Mp', V _Mp') revise with the illumination under the different condition, temperature and irradiation loss coefficient after, this analytical expression of substitution can obtain the I-V family curve of the sun battle array under the different condition.

Step 3, sun battle array energy equilibrium computation model;

By V _{S_bus}, V _{S_dioline}Value is calculated V by Equ.12 _{S_op1}Value calculates corresponding I by formula Equ.15 _{S_op1}Value, and then set up I _{S_opl}And the funtcional relationship between the time month;

For the parameter η among the Equ.13 _BDR, η _Line, V _BusBe known quantity, at shadow region I _SA(t) be zero, I _Load(t) utilize existing moonlet to do approximate processing in the average of rail load current data, i.e. I _Load(t) :=I _{Load_mean}(c), wherein, ' :=' expression ' being defined as ', I _SA(t)=0A.

Battery discharging Current calculation: shade phase, battery discharging electric current I _d(t) V in the formula _Bat(t) as an integrand.This function is the linear function of being determined in rail discharge first pressing and discharge final pressure by accumulator, and its discharge first pressing is constant, and discharge final pressure is by existing moonlet battery discharging final pressure mean approximation.

For Equ.11Te, te is known, V _{S_op1}And

The integration item can be asked by foregoing description, I _{S_load_mean}(c) utilize existing moonlet illumination period load current mean approximation.Above-mentioned parameter, bring Equ.11 into, because I _{S_load_mean}(c) * (Te-te) reach Be approximately constant term, and I _{S_op1}(c) determined by Equ.12 and Equ.15, thereby, I _{S_op1}(c) can be expressed as: I _{S_op1}(c)=I _{S_op1}(month), final, obtain Q _{S_residual}(c)=Q _{S_residual}(month), namely obtain the time dependent function of unnecessary electric weight that sun battle array provides energy, thereby can determine the sun battle array life-span.

Embodiment 2 is as follows:

Present embodiment by elaborating of present embodiment, further specifies implementation process of the present invention and engineering application process take China space flight HY-1B moonlet sun battle array as object.

The angle of step 1, the solar distance factor, track ecliptic time, sunray and sun tactical deployment of troops line is determined;

Moonlet orbit altitude 645km, southbound node local time 15:00PM ± 30min---according to orbit altitude, southbound node local time and prediction zero-time, call STK software, calculate solar distance factor F _Rd, orbital period, track ecliptic time, track sunray and sun tactical deployment of troops line the Changing Pattern of angle theta (t), obtain time dependent quantitative data, be used for follow-up sun battle array output power and calculate and Energy Balance Analysis.

F _Rd=[1,033 1.023 1.008 0.991 0.977 0.968 0.968 0.976 0.991 1.008 1.024 1.033] (the solar distance factor of every month in a year, as shown in Figure 4); Orbital period: Te=100.8min; Track ecliptic time: te=33.5217min minute; Solar incident angle θ (t) has periodically, is illustrated in figure 5 as solar incident angle year Changing Pattern curve.

Step 2, sun battle array I-V curve model;

(1) sun battle array open-circuit voltage and short-circuit current irradiation decline and fall factor computation model;

Because the orbit altitude of HY-1B moonlet is 645km, according to formula Equ.5 displacement calculating damage dose y month Changing Pattern: y=f (month) in time.Utilizing formula Equ.8-9 to calculate respectively sun battle array open-circuit voltage irradiation declines and falls over time function K of the factor _VRAD=gv (month) declines with sun battle array short-circuit current irradiation and falls over time function K of the factor _IRAD=gI (month).

(2) sun battle array characteristic feature point calculation of parameter model;

For computing formula Equ.2-3, wherein, V _Ov=2.65V, V _Mp=2.32V, β _VBOL=-6.7mV/ ° C, I _SC=0.396A, I _Mp=0.375A, a _I=0.014mA/cm ²° C, N _p=114, N _s=18, T=82 ° of C(by sun battle array temperature model as can be known, illumination period, sun battle array temperature can rise to rapidly equilibrium temperature, thereby this sentences the highest equilibrium temperature T _SAS=82 ° of C are as HY-1B moonlet sun battle array temperature); θ (t), F _RdProvided by step 1, and K _VRAD=gv (month), K _IRAD=gI (month).And then, set up respectively the expression formula of shape such as Equ.14, the expression formula that obtains is brought into Equ.1, and finally set up the time dependent rule of HY-1B moonlet sun battle array I-V curve, Fig. 6 is the I-V curve of a certain given time in the HY-1B moonlet sun battle array life cycle.

Step 3, sun battle array energy equilibrium computation model;

By V _{S_bus}=29.3V, V _{S_dioine}=2.0 V values are calculated V by Equ.12 _{S_op1}=31.3V value calculates corresponding I by formula Equ.15 _{S_op1}Value, and then set up I _{S_op1}And the funtcional relationship I between the time month _{S_opl}=I _{S_opl}(month);

For the parameter η among the Equ.13 _BOR=0.92, η _Line=0.9673, V _Bus=28.6V is known quantity, I _Load(t), at shadow region I _SA(t)=0A, as calculated: I _Load(t) :=I _{Load_mean}(c)=9.0A, wherein, ' :=' expression ' being defined as '.

The shade phase, the battery discharging electric current I _d(t) V in the formula _Bat(t) as an integrand.This function is at rail discharge first pressing and the definite linear function of discharge final pressure by accumulator, and its discharge first pressing is constant, discharge final pressure is by existing moonlet battery discharging final pressure mean approximation, and the discharge first pressing is 1.383 V*18(battery pack Series Sheet accumulator body numbers)=24.8940V, discharge final pressure average 21.6V.

Te=100.8min, te=33.5217min, and the V by calculating _{S_op1}And I _{S_load_mean}(c)=11.4A brings Equ.11 into, because I _{S_load_mean}(c) * (Te-te) reach Be approximately constant term, and I _{S_op1}(c) determined by Equ.12 and Equ.15, thereby, I _{S_op1}(c) can be expressed as: I _{S_op1}(c)=I _{S_op1}(month), thus, Equ.11 is converted into Q _{S_residual}(c)=Q _{S_residual}(month), namely obtain the time dependent function of unnecessary electric weight that sun battle array provides energy, Figure 7 shows that over time curve of unnecessary electric weight.As seen from the figure, unnecessary electric weight under the combined action of the cycle influence factors such as solar incident angle, presents obvious periodicity along with the solar distance factor, and unnecessary electric weight continuous decrease, is sun battle array end of life position with the horizontal line intersection.

Claims (2)

1. moonlet sun battle array life-span prediction method based on I-V curve and energy equilibrium, it is characterized in that: the method realizes as follows:

The angle of step 1, the solar distance factor, track ecliptic time, sunray and sun tactical deployment of troops line is determined;

According to orbit altitude, southbound node local time and prediction zero-time, calculate the Changing Pattern of angle of the solar distance factor, orbital period Te, track ecliptic time, every rail sunray and the sun tactical deployment of troops line of every day, obtain time dependent quantitative data, be used for follow-up sun battle array I-V curve and Energy Balance Analysis;

Step 2, sun battle array I-V curve model are determined;

Make up sun battle array computation model according to sun battle array characteristic, consider simultaneously the impact of solar incident angle, irradiation decay, day ground factor, loss factor factor, calculate sun battle array output voltage, output current under Various Seasonal, different track condition and the different operating modes, reach in real time the secular variation situation to characterize sun battle array output power;

Take the I-V curvilinear characteristic point of standard state as parameter, consider that multiple environmental factor on the impact in sun battle array life-span, calculates the output characteristics of sun battle array; Utilize the computer analyzing model of formula (Equ.1) sun battle array I-V curve, obtain the I-V family curve of the sun battle array under the different condition; This model during less than 2 solar constants, has very high accuracy in intensity of illumination; The light conditions of sun synchronous orbit moonlet satisfies this condition:

$\left\{\begin{array}{c}I={\mathrm{Isc}}^{\&prime;}(1-C_1\&times;\{\exp [V/(C_2\&times;V_{\mathrm{ov}}\&prime;)]-1\left\}\right)\\ C_1=[1-({I_{\mathrm{mp}}}^{\&prime;}/{\mathrm{Isc}}^{\&prime;})]\&times;\left\{\exp \right[-{V_{\mathrm{mp}}}^{\&prime;}/(C_2\&times;{V_{\mathrm{ov}}}^{\&prime;}){]}^{}\}\\ C_2=[({V_{\mathrm{mp}}}^{\&prime;}/{V_{\mathrm{ov}}}^{\&prime;})-1]/1n(1-{I_{\mathrm{mp}}}^{\&prime;}/{\mathrm{Isc}}^{\&prime;})\end{array}\right.---(\mathrm{Equ}.1)$

In the formula:

I---sun battle array output current, unit are A;

Isc'---sun battle array short-circuit current, canonical parameter or measured value, unit are A;

C ₁---formula coefficient 1;

V---sun battle array output voltage, unit are V;

C ₂---formula coefficient 2;

V _Ov'---sun battle array open-circuit voltage, canonical parameter or measured value, unit are V;

I _Mp'---sun battle array best operating point output current, canonical parameter or measured value, unit are A;

V _Mp'---sun battle array best operating point output voltage, canonical parameter or measured value, unit are V;

Sun battle array open-circuit voltage and best operating point output voltage computation model are as follows:

$\left\{\begin{array}{c}{V}_{\mathrm{ov}}\&prime;=(V_{\mathrm{ov}}+{\mathrm{\&beta;}}_{\mathrm{VBOL}}\&times;(T-25))\&times;0.98\&times;0.98\&times;N_s\&times;K_{\mathrm{VRAD}}\\ V_{\mathrm{mp}}\&prime;=(V_{\mathrm{mp}}+{\mathrm{\&beta;}}_{\mathrm{VBOL}}\&times;(T-25))\&times;0.98\&times;0.98\&times;N_s\&times;K_{\mathrm{VRAD}}\end{array}\right.---(\mathrm{Equ}.2)$

In the formula:

V _Ov---single solar cell open-circuit voltage, unit are V;

V _Mp---single solar cell best effort point voltage, unit are V;

β _VBOL---single solar cell beginning of lifetime voltage temperature coefficient, unit are V/ ℃;

K _VRAD---sun battle array open-circuit voltage irradiation declines and falls the factor;

T---sun battle array temperature, unit is ℃;

Sun battle array short-circuit current and best operating point Current calculation model are as follows:

$\left\{\begin{array}{c}\mathrm{Isc}\&prime;=({\mathrm{Isc}}_{}+{\mathrm{\&alpha;}}_I\&times;(T-25))\&times;0.98\&times;0.98\&times;0.98{\&times;N}_p\&times;\cos \mathrm{\&theta;}\left(t\right)\&times;F_{\mathrm{rd}}\&times;K_{\mathrm{IRAD}}\\ I_{\mathrm{mp}}\&prime;=(I_{\mathrm{mp}}+{\mathrm{\&alpha;}}_I\&times;(T-25))\&times;0.98\&times;0.98\&times;0.98\&times;N_p\&times;\cos \mathrm{\&theta;}\left(t\right)\&times;F_{\mathrm{rd}}\&times;K_{\mathrm{IRAD}}\end{array}\right.---(\mathrm{Equ}.3)$

I _SC---single solar cell short-circuit current, unit are A;

I _Mp---single solar cell best operating point electric current, unit are A;

α _I-single solar cell current temperature coefficient, unit are A/ ℃;

θ (t)---the angle of sunray and sun tactical deployment of troops line direction in the circle track, unit is degree;

T---sun battle array temperature, unit is ℃;

K _IRAD_ _ _ _ _ _ _ _ sun battle array short-circuit current irradiation declines and falls the factor;

F _Rd---the solar distance factor;

Utilize " sun battle array open-circuit voltage and short-circuit current irradiation decline and falls factor computation model " prediction LEO track radiation environment on the impact of satellite solar cell output parameter decay, Isc is K in this model _IRAD, Vov is K _VRAD

A. the mode input parameter-definition is as follows:

Battery types: unijunction GaAs solar cell; Quartz glass coverslip thickness: 120 μ m; Orbit altitude: 300km ~ 3000km; Inclination angle: only for 99 °; Chronomere: month;

B. the model output parameter is defined as follows:

Peak power output P _Max, short-circuit current I _Sc, open-circuit voltage V _Ov, its output form: provide P _Max, I _ScAnd V _OvAfter m month, P _Max, I _ScAnd V _OvBe the number percent of initial value, namely provide P _Max, I _ScAnd V _OvFunction about time month;

For this sun battle array open-circuit voltage and short-circuit current irradiation decline the computation model of the factor falls below:

The multiple orbital attitudes displacement damage dose is calculated as follows: x is orbit altitude, and month is at rail moon number, and y is the displacement damage dose that calculates;

When 300km＜=x＜=600km, computing formula is:

y＝14（A ₀+A ₁·x+A ₂·x ²+A ₃·x ³+A ₄·x ⁴+A ₅·x ⁵）·month （Equ.4）

Wherein, A0=-5.72637E6, A1=69074.68933, A2=-329.19032,

A3=0.77634，A4=-9.13546E-4，A5=4.49106E-7

When 600km＜x＜=1000km, computing formula is:

y＝14（A ₀+A ₁·x+A ₂·x ²+A ₃·x ³+A ₄·x ⁴）·month （Equ.5）

Wherein, A0=-5.80893E7, A1=321272.30685, A2=-663.23216, A3=0.59526, A4=-1.77968E-4

When 1000km＜x＜=3000km, computing formula is:

y＝14（A ₀+A ₁·x+A ₂·x ²+A ₃·x ³+A ₄·x ⁴+A ₅·x ⁵）·month （Equ.6）

Wherein, A0=5.01219E8, A1=-1.76649E6, A2=2453.54778,

A3=-1.65135，A4=5.32602E-4，A5=-5.18233E-8

The computation model of the Pmax of GaAs/Ge solar cell, Isc and Voc is:

Peak power output decay, the i.e. computation model of Pmax:

P _max=1.0-C×log10(1+(y/Dx)) （Equ.7）

Wherein, C=0.242, Dx=3.47e9, y are the displacement damage dose that calculates;

Short-circuit current decay, the i.e. computation model of Isc:

K _IRAD=Isc=1.0-C×log10(1+(y/Dx)) （Equ.8）

Wherein, C=0.213, Dx=8.3e19

Open-circuit voltage decay, the i.e. computation model of Voc:

K _VRAD=Vov=1.0-C×log10(1+(y/Dx)) （Equ.9）

Wherein, C=0.07, Dx=1.8e9

Step 3, sun battle array energy equilibrium computation model are determined;

Carry out energy equilibrium when calculating, according to the data that provide on rail data or ground the critical conditions of energy equilibrium is being carried out Real Time Monitoring, if sun battle array provides the unnecessary electric weight Q of energy _Residual(c) by on the occasion of changing into less than or equal to zero arbitrary value, show that then sun battle array has been in the major injury state, and Q _Residual(c) calculating formula is:

$Q_{\mathrm{residual}}\left(c\right)=I_{\mathrm{SA}}\left(c\right)\&times;(\mathrm{Te}-\mathrm{te})-I_{\mathrm{load}\_\mathrm{mean}}\left(c\right)\&times;(\mathrm{Te}-\mathrm{te})-1.02\&times;{\&Integral;}_0^{\mathrm{te}}{I}_d\left(t\right)\&times;\mathrm{dt}---(\mathrm{Equ}.10)$

Wherein:

Q _Residual(c)---at the available unnecessary electric weight of rail c circle sun battle array, unit is C;

Te---time shade phase, unit is s;

I _SA(c)---at rail c circle square formation current clamp point current value, unit is A;

I _{Load_mean}(c)---illumination period load current I _Load(A), it is that unit is A at the rail c mean value in circle per cycle of load current;

I _d(t)---the shade phase, battery discharging electric current, unit are A;

According to the equation of designated period of time sun battle array I-V curve, providing corresponding area of illumination busbar voltage V _{S_bus}And sun battle array isolating diode and power cable pressure drop sum V _{S_dioline}The time, obtain sun battle array operating voltage clamped point V on this designated period of time I-V curve _Op1The current value I at place _{S_op1}Calculated as can be known by energy equilibrium, the sun battle array of this designated period of time provides the unnecessary electric weight Q of energy _Residual(c) can be expressed as:

$Q_{s-\mathrm{residual}}\left(c\right)=I_{s\_\mathrm{opl}}\left(c\right)\&times;(\mathrm{Te}-\mathrm{te})-I_{s\_\mathrm{load}\_\mathrm{mean}}\left(c\right)\&times;(\mathrm{Te}-\mathrm{te})-1.02\&times;{\&Integral;}_0^{\mathrm{te}}{I}_d\left(t\right)\&times;\mathrm{dt}---(\mathrm{Equ}.11)$

In the formula:

I _{S_opl}Sun battle array operating voltage clamped point V on the-indication I-V curve in period _Op1The current value at place, unit is A;

I _{S_load_mean}---designated period of time area of illumination load current/at the mean value of all load current data of rail, unit is A;

I _d(t)---the designated period accumulator is at the discharge current value in shadow region, and unit is A;

Sun battle array operating voltage point output power computation model is as follows:

P _SA(t)＝V _bus(t)I _op1(t)， I _SA(t)＝I _op1(t)

Further can get:

P _{s_op1}(c)＝V _{s_bus}(c)I _{s_op1}(c)

V _{s_op1}(c)＝V _{s_bus}(c)+V _{s_dioline} （Equ.12）

In the formula:

T--c moment in the circle orbital period, 0＜t＜Te, wherein, Te is the orbital period, unit is s;

P _SA---sun battle array output power, unit is W;

P _{S_OP1}(c)---c circle sun battle array is output as clamped point V _{S_op1}The time output power, unit is W;

I _{S_opI}(c)---sun battle array operating voltage clamped point V on the c circle I-V curve _{S_op1}The time current value, unit is A;

V _{S_bus}---the area of illumination busbar voltage, unit is V;

V _{S_dioline}---sun battle array isolating diode and power cable pressure drop sum, unit is V;

For in the rail power-supply system, because power-supply controller of electric is so that the illumination period busbar voltage remains definite value, thereby can think: under the prerequisite of power-supply controller of electric normal operation, the illumination period busbar voltage is constant all the time; Simultaneously, obtaining V _{S_dioline}After the value, can be enough I-V curve by above-mentioned foundation obtain designated period of time clamped point current value I _{S_op1}(c), calculate to be used for energy equilibrium;

If system prediction obtains certain designated period of time Q _Residual(c)=0, illustrate that then sun battle array is to the longevity at this moment;

Wherein, when carrying out the calculating of battery pack discharge current, the discharge current of battery pack depends on the discharge power of battery pack, discharge regulator efficiency, battery pack supply line dissipation factor, battery voltage factor;

The shadow region, the battery pack discharge current is:

$I_d\left(t\right)=\frac{(I_{\mathrm{load}}\left(t\right)-I_{\mathrm{SA}}\left(t\right))\&times;V_{\mathrm{bus}}}{{\mathrm{\&eta;}}_{\mathrm{BDR}}\&CenterDot;{\mathrm{\&eta;}}_{\mathrm{line}}\&CenterDot;V_{\mathrm{bat}}\left(t\right)}$

In the formula:

T--c moment in the circle orbital period, 0＜t＜Te, wherein, Te is the orbital period, unit is s;

I _Load(t)--at the time dependent function of rail load current demand;

η _BDR--the discharge regulator efficiency;

n _Line--battery pack supply line dissipation factor;

V _Bat(t)--the battery pack sparking voltage; Based in the battery discharging first pressing of rail c circle track and discharge final pressure value, can think approx V _Bat(t) just be depressed into discharge final pressure linear change by discharge;

V _Bus: busbar voltage during discharge, unit is V;

Wherein: shadow region sun battle array I _SA(t) electric current is zero, V _Bat(t) be an integrand, this function is at rail discharge first pressing and the definite linear function of discharge final pressure by accumulator.

2. a kind of moonlet sun battle array life-span prediction method based on I-V curve and energy equilibrium according to claim 1, it is characterized in that: described sun battle array temperature is calculated as follows by sun battle array temperature model:

Sun battle array temperature changes with the variation of satellite turnover shadow state, the shadow zone, ground, and sun battle array temperature descends gradually, until be down to out the minimum temperature before the shadow; Illumination period, sun battle array temperature rises rapidly from going out the movie queen, until reach photoperiodic equalized temperature point, after this temperature remains unchanged until satellite enters the ground shadow phase of next rail ring, goes round and begins again;

The simplified model of sun battle array temperature variation is as follows:

Within the ground shadow phase, sun battle array temperature drops to ground shadow phase minimum temperature from the highest photoperiodic equilibrium temperature linearity, goes out the movie queen, and sun battle array temperature rose to 60 ℃ from ground shadow phase minimum temperature in 8 minutes, in 20 minutes, rise to the highest equilibrium temperature of illumination period from 60 ℃, until advance shadow next time;

The highest photoperiodic equilibrium temperature, the default value of shadow phase minimum temperature be respectively: the highest photoperiodic equilibrium temperature Tx; Ground shadow phase minimum temperature T _SAE

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