CN113676132A - Satellite solar power module system - Google Patents

Abstract

A satellite solar power module system, comprising: the solar battery pack comprises a plurality of solar battery units, wherein bypass safety parts are arranged in the solar battery units, when the bypass safety parts are communicated, solar battery pieces connected with the bypass safety parts in parallel are discharged out of a power supply circuit of the solar battery units, the output end of each solar battery unit is provided with an MPPT unit, the MPPT unit is used for maintaining the output power of the solar battery units at a maximum output power point, and an actuating mechanism is arranged and configured to be capable of maintaining at least one solar battery unit in a fully-shielding, semi-shielding or non-shielding state so as to obtain different maximum output power points under the control of the MPPT algorithm, wherein the change of the maximum power point and the change sequence from non-shielding to full-shielding are in a nonlinear relation.

Description

Satellite solar power module system

Technical Field

The invention relates to a power supply module used by a satellite, in particular to a satellite solar power supply module system.

Background

At present, satellite technology becomes a development direction of aerospace technology in various countries, wherein micro satellites are widely concerned by people due to the characteristics of small size, light weight, low cost and the like. The design and development period of the micro satellite is short, the micro satellite is convenient for modularization and batch production, and the advantages which are not possessed by other satellites are widely adopted.

With the development of commercial aerospace, more stringent requirements are put on commercial satellites, and the core requirements of the commercial satellites are as follows: the development cost is low, the development period is short, namely the business mode of commercial aerospace determines that the satellite needs to be shifted from single customization to productization, serialization and shelving, and therefore the design and development of the commercial satellite are required to have good adaptability and expandability. The satellite energy system is used as a large component of the satellite system, the requirements are the same, the adaptability is wide, and the expandability is strong, so that the satellite energy system is one of important design ideas of commercial satellite energy systems.

The power supply system of the satellite is one of several core systems of the satellite, is used for providing power for the whole satellite, and is the life line of the satellite. For a low orbit microsatellite, a power supply system must have the characteristics of high reliability, small volume, light weight, high efficiency and the like.

CN107579587A discloses an energy system suitable for LEO satellite and its control method, which comprises a solar cell array, a PPT circuit unit, a storage battery, a capacitor array, a satellite platform load and a remote measurement and control unit; the MPPT circuit unit performs peak power tracking on the solar cell array in a triple redundancy hot backup mode by adopting three DC-DC conversion modules connected in parallel, closed-loop control is performed on the MPPT circuit unit by adopting a majority voting control circuit, and each control circuit generates a driving signal to perform closed-loop control on the MPPT circuit corresponding to the control circuit according to an output voltage signal and an output current signal of the solar cell array module and a voltage signal and a current signal of a storage battery pack so as to realize maximum power tracking on the solar cell array module and charge management on the storage battery pack.

The main stream optimization direction of the MPPT algorithm adopted in the prior art at present is to make the algorithm contact the maximum output power point as much as possible under the condition that the power curve is unimodal or multimodal, but for special electric equipment used in space such as satellites, the load required by the electric appliances and storage batteries carried on the special electric equipment is not constant, the demand of the electric loads becomes very low or even needs to be maintained in a lower state under the condition of executing certain tasks, at this time, if the MPPT algorithm is still used for controlling the output of the solar cell, the electric generation is excessive, at this time, the extra energy storage by only using the storage battery with limited capacity is insufficient, and a large amount of energy loss is caused. And unlike the solar cell array on the ground which has an energy consumption shunting device with multi-level backup, the satellite equipment which independently works in the space isolation state generally does not have the capacity of coping with a large amount of residual electricity. Therefore, how to change the output power of the satellite capacity unit by adjusting the maximum output power point searched under the algorithm according to the actual power demand of the satellite under the condition of adjusting the maximum output power output of the satellite capacity unit by adopting the MPPT algorithm becomes a problem to be solved.

Disclosure of Invention

To solve at least some of the problems in the prior art, the present invention provides a satellite solar power module system, including: the solar battery pack comprises a plurality of solar battery units, wherein bypass safety parts are arranged in the solar battery units, when the bypass safety parts are communicated, solar battery pieces connected with the bypass safety parts in parallel are discharged out of a power supply circuit of the solar battery units, the output end of each solar battery unit is provided with an MPPT unit, the MPPT unit is used for maintaining the output power of the solar battery units at a maximum output power point, and an actuating mechanism is arranged and configured to be capable of maintaining at least one solar battery unit in a fully-shielding, semi-shielding or non-shielding state so as to obtain different maximum output power points under the control of the MPPT algorithm, wherein the change of the maximum power point and the change sequence from non-shielding to full-shielding are in a nonlinear relation.

According to the MPPT algorithm and the function, the maximum output power point of the solar battery is tracked, the maximum output power point is related to the photovoltaic characteristic and the environment, and the maximum output power point basically does not change under the conditions that basic parameters are fixed and the environment is stable. However, the load demand of some satellite electric devices is not simple and unchangeable, different electric devices can be called according to the change of work tasks, different power is output to different devices, and because the capacity of a storage battery on the satellite is not infinite, the accommodating space for providing surplus electric quantity is limited, so that some satellites need to reduce the output power during the illumination period so as to reduce the power consumption of the electric devices and prevent the storage battery from being overcharged. Compared with the implementation difficulty of adjusting the maximum power output point controlled by MPPT by adjusting the ambient temperature, the scheme of adjusting the satellite attitude to shield the positions of partial solar cells on the satellite so as to reduce the maximum output power point of the integrally connected solar cells in series has higher operability. In addition, for the multi-peak problem of the MPPT algorithm under the shielded condition, the scheme is different from the scheme that the maximum value of the multi-peak is found out in a complex algorithm optimizing mode on the mainstream, the method only needs to adopt a common single-peak scheme, even the opposite is realized, and under the condition that the output power needs to be reduced, the method also needs to maintain the output power point of the solar cell at a maximum value point with a smaller peak value instead of the maximum value point.

Preferably, the solar cell system further comprises a control management module electrically connected to the output end of the solar cell unit and the bypass fuse, wherein the control management module determines whether the solar cell unit is in the fully-shielded, half-shielded or non-shielded state by detecting and determining the change of the output power of the solar cell unit and the on-off condition of the bypass fuse.

The invention has another advantage that the semi-shielding state with smaller output power can be avoided by utilizing the actuation adjustment of the satellite attitude, so that the time of the satellite in the semi-shielding state is actively reduced as much as possible under the condition that the satellite electric equipment needs high-power supply at any moment, and the large loss caused by the fact that the electric equipment cannot complete the work under the condition that the output power cannot be ensured for a long time is prevented.

Preferably, when the electrical equipment in the satellite requires high-power supply for a long time, the control management module detects a change of a maximum power output point searched by the MPPT algorithm and/or an opening/closing condition of the bypass safety part to activate the actuating mechanism to drive the solar cell module in the half-shielding state to change to the full-shielding state or the non-shielding state when it is determined that the solar cell unit is changed from the full-shielding state to the half-shielding state or from the non-shielding state to the half-shielding state.

Preferably, the bypass fuse is provided in parallel to the solar cell circuit in a manner opposite to the polarity of the solar cell.

Preferably, the power source for driving the actuating mechanism is provided by the solar battery unit in the solar battery pack in the non-shielding state.

The design of adding the control management module in the circuit of the solar battery pack of the satellite for outputting the electric power outwards enables the power of the electric power transmitted outwards by the solar battery pack to be adjusted, and particularly the satellite belongs to special equipment operating in a special space environment and has higher working requirements on all parts or electric devices on the satellite. The control management module which is erected and can generate the optimal MPPT instruction can track the maximum output power of the solar battery pack to adjust the output parameters of the solar battery pack, so that the electric power generated by the solar battery pack can be utilized at the highest efficiency, the working efficiency of the whole satellite is improved, meanwhile, some unnecessary energy losses are reduced, and the simplification degree of the whole satellite is further improved. In addition, a wireless transmission mode is adopted between the control management module and the control loop, so that the control management module and the control loop can be respectively placed at a longer distance, due to the special characteristics of the satellite structure, an independent area is often arranged on the control management module to serve as a protection working area of electric equipment or electric equipment, power supply equipment is arranged near a solar cell set optical wing expansion plate, a certain distance is reserved between the solar cell set optical wing expansion plate and the control loop, the wireless transmission mode at least saves the circuit design from the control management module to the vicinity of the solar cell set on the control loop, and the whole circuit of the satellite is optimized while the whole circuit of the satellite is improved. In addition, the control management module is additionally provided with a function of detecting the residual capacity of the storage battery pack, so that the control management module can detect the residual capacity of the storage battery pack in real time and can control other electric equipment on the satellite to properly reduce the working load or close part of unnecessary electric equipment to prevent the over-discharge condition of the storage battery pack when the residual capacity is insufficient, and the service life of the storage battery pack is prolonged.

Preferably, the control management module includes an IC chip, the IC chip at least includes an MPPT unit, the MPPT unit is electrically connected to the power output terminal of the solar cell set to collect the output voltage and the output current, and generates an optimal MPPT instruction according to an MPPT algorithm stored in the MPPT unit, and the control management module adjusts and controls the output power of the solar cell set according to the optimal MPPT instruction.

The integrated control management module integrates the whole components of the control management module into a chip, and the chip-level control management mode can be applied to the design and application of different satellites, and is different from the design ideas of singleness, customization, numerous components and parts and complex circuits of control management loops in the traditional satellite battery system.

Preferably, the control management module is composed of at least 2 IC chips, wherein the 2 IC chips and the circuits matched with the IC chips are independently arranged, so that at least 2 complete sets of mutually-safe IC chips are formed in the control management module.

At least 2 sets of complete IC chip control loops are arranged in the control management module, and the control loops mutually form a hot backup mode, so that the satellite runs for a long time in a severe environment of space and is lack of manual maintenance, and the danger that the output porosity of the solar battery pack cannot be controlled and the storage battery pack is over-charged and over-discharged due to the fact that the integral control management module cannot normally work when 1 set of IC chips fails due to space radiation or other external reasons is prevented. And another complete set of IC chip is used as a hot backup, so that the control function of the other complete set of IC chip can be replaced at least when the other complete set of IC chip cannot work, the satellite can continue to operate normally, and the whole service life of the satellite is greatly prolonged.

Preferably, the control management module further comprises a charging control unit, wherein the charging control unit comprises a storage battery pack detection unit, and the storage battery pack detection unit is electrically connected to the storage battery pack and used for detecting a storage battery pack voltage signal and a storage battery pack current signal.

Preferably, the charging control unit further comprises a charging control decision unit, and the charging control decision unit is capable of generating at least one optimal charging control command according to a charging control strategy program stored thereon in combination with the voltage signal and the current signal of the storage battery pack detected by the storage battery pack detection unit.

The charging control unit for controlling the charging of the storage battery pack is arranged on the IC chip and is divided into the storage battery pack detection unit and the charging control decision unit according to different functions, the storage battery pack detection unit detects the voltage and the current value of the charging end of the storage battery pack and transmits the numerical values to the charging control decision unit, and the charging control decision unit compares the real-time charging voltage value with the known charging end point voltage value of the storage battery pack to generate at least one optimal charging instruction for reducing the charging current for the storage battery pack with the real-time voltage close to the charging end point, so that the problem of overcharging caused by continuous large-current charging of the storage battery pack is avoided. Since the battery pack may have uncontrollable side reactions other than cell reaction when overcharged, such as hydrogen and oxygen generated by the reaction of electrolyzed water, if these two gases are discharged in time, there may be a risk of explosion in the vicinity of the battery pack, which may cause irreparable damage to the satellite.

Preferably, the MPPT unit at least includes a solar cell set detection unit electrically connected to the solar cell set for detecting an output voltage and an output current of the solar cell set.

Preferably, the MPPT unit further includes an MPPT control decision unit, and the MPPT control decision unit is capable of generating at least one optimal MPPT control command according to the MPPT algorithm stored thereon in combination with the output voltage and the output current of the solar battery detected by the solar battery detection unit.

Preferably, the IC chip further includes a control circuit, the control circuit is electrically connected to the power output terminal of the solar battery pack and the power input terminal of the storage battery pack, respectively, wherein the control circuit can control the output efficiency of the solar battery pack and/or the charging mode of the storage battery pack according to the optimal charging control instruction and/or the optimal charging MPPT control instruction generated by the charging control decision unit and the MPPT control decision unit.

The MPPT unit is integrated on the IC chip and can detect the output voltage and current of the solar battery pack and generate an instruction capable of controlling the panel solar battery pack to output according to the maximum power according to the MPPT algorithm. The solar battery pack can output the maximum power by adopting the MTTP topological structure, so that the solar battery pack can supply power to electric equipment and a storage battery pack in a large-current output mode as far as possible within the limited light contact time in the illumination period, more solar radiation energy can be collected as far as possible, the capacity of adapting to instantaneous pulse large load is strong, and the size and the quality of the whole power supply system can be reduced. The MPPT algorithm has obvious power output advantages at the initial service life of a power supply system, and has advantages for the high-efficiency operation of the power supply system of the micro satellite in a complex space environment.

Preferably, the IC chip further integrates a remote control unit, a signal input end of the remote control unit is electrically connected to the charging control decision unit and the MPPT control decision unit, wherein the remote control unit receives the optimal charging control instruction and/or the optimal charging MPPT control instruction transmitted by the charging control decision unit and the MPPT control decision unit, and wirelessly transmits the optimal charging control instruction and/or the optimal charging MPPT control instruction to the control loop.

Preferably, the IC chip further integrates an SOC detection unit, the SOC detection unit is electrically connected to the storage battery pack for calculating the remaining capacity of the storage battery pack according to an SOC detection program set thereon, and the control circuit is further electrically connected to the SOC detection unit for adaptively adjusting the load intensity of the electric device according to the remaining capacity of the storage battery pack detected by the SOC detection unit.

Drawings

FIG. 1 is a schematic diagram of the overall circuit connection of the present invention;

FIG. 2 is a schematic circuit diagram of a control management module according to the present invention;

FIG. 3 is a U-I relationship diagram for three shielding states of the present invention;

in the figure: 100. a solar cell array; 200. a control management module; 210. an IC chip; 220. a control loop; 300. a battery pack; 400. an electricity-consuming device; A. a first power output point; B. a second power output point; C. a third power output point.

Detailed Description

The following detailed description is made with reference to the accompanying drawings.

Fig. 1 shows a satellite solar power module, and since the present invention is used for satellites in space, the present invention at least includes a solar cell set 100 for acquiring solar energy in space as a main energy source of the satellites. The solar cell array 100 is formed by combining a plurality of solar cells arranged in a certain arrangement manner.

Each solar cell has a sheet or plate structure, wherein the solar cell can be made of various novel composite materials, such as triple junction gallium arsenide (GaAs)GaInP₂GaAs/Ge) material, copper indium selenide (CuInSe)₂) Material, Copper Indium Gallium Selenide (CIGS) material, TiO₂The nano-crystalline material and the single-crystal silicon material made of the same material have different photoelectric conversion efficiencies, for example, the photoelectric conversion efficiency of the triple-junction gallium arsenide is over 28%, while the photoelectric conversion efficiency of the single-crystal silicon material is only about 12-14%, but the triple-junction gallium arsenide has higher cost due to complex manufacturing process. Therefore, the material of the solar cell set 100 is selected according to the use requirement of the satellite, the working environment, the manufacturing budget, and other factors.

The solar array 100 may be configured as a low voltage battery array, so that the satellite, when applied to an area with strong illumination variation, can still maintain high overall output power if part of the solar cells are shielded. Preferably, the solar cell set 100 can be adaptively changed and arranged according to specific use conditions or use environments of the satellite, for example, for different types of satellites such as a small satellite with low orbit, a satellite with high power using equipment 400, a satellite operating in an orbit with uniform light irradiation, and the like, so as to adapt to the different use conditions of the satellite.

Since the satellite moves in space in a long-term, orbiting motion about a fixed primary star (e.g., the earth), the satellite will be in the sun's shadow for a period of time, referred to as the shadow period. It is apparent that the solar cell set 100 cannot or can receive only little light during the shadow period, and thus the solar cell set 100 cannot perform power supply or photoelectric conversion operation during the shadow period. A period of time excluding the shadow period in the full period of the satellite moving around the main satellite is referred to as an illumination period, and at this time, the solar cell set 100 may collect sunlight at the maximum power to perform photoelectric conversion to generate electric energy by adjusting the attitude of the satellite.

In order to ensure that the satellite can be normally powered on to maintain the movement and attitude adjustment of the satellite or the continuous and stable operation of the power utilization functional equipment on the satellite in the period from the movement to the shadow period, the storage battery pack 300 is further arranged in the satellite power supply module provided by the invention. The battery pack 300 is electrically connected with the solar battery pack 100 to realize the power intercommunication between the battery pack 300 and the solar battery pack 100, and the satellite can selectively turn on the battery pack 300 to supply power to the electric equipment 400 on the whole satellite in the case that the satellite enters a shadow period. For the purpose of charging the battery pack 300, the solar cell pack 100 performs a charging operation for the battery pack 300 through its electrical connection with the battery pack 300 during the light period to receive light and generate electricity.

In order to adapt to the harsh environment in outer space and the reduced requirements of the overall weight and volume of the satellite, the material of the battery pack 300 is generally selected from the types with higher energy density, such as lithium ion batteries, nickel-chromium batteries, nickel-hydrogen batteries, and the like. Although the lithium ion storage battery has high energy density and good charge and discharge performance, the discharge cut-off voltage of the lithium ion storage battery is about 2.7V, the charge termination voltage is about 4.2V, and the average discharge voltage is about 3.5V, compared with the average discharge voltage of a nickel-metal hydride storage battery and a cadmium-nickel storage battery which is about 1.25V, the number of lithium battery packs is only one third of the number of nickel-metal hydride batteries and cadmium-nickel batteries, and the cost is greatly reduced. However, the lithium ion batteries also have the risk of explosion of the batteries due to overcharge and overdischarge, and for a satellite running for a long time, voltage difference is formed between each lithium ion battery and other single lithium ion batteries in the battery pack 300 in a long-term charge-discharge cycle, so that the risk of overcharge and overdischarge of the single lithium ion batteries is possibly increased in the unified charging or discharging operation of the battery pack 300. However, for a small satellite running in a low orbit, the lithium ion storage battery can be adopted on the small satellite running in the low orbit to reduce the volume and the weight of the satellite due to small volume, single function, shallow discharge depth of the storage battery and low requirement on the whole service life of the satellite.

The device requiring power provided on the satellite is essentially a load, and the load needs to be supplied with power continuously in a normal condition to ensure its normal operation, so that the solar cell set 100 and the battery set 300 are electrically connected to the power-consuming device 400. Preferably, during the time period when the satellite is in the illumination period, the solar cell set 100 receives sunlight to perform photoelectric conversion to generate electric power, and then divides the electric power into at least two parts, one part is used for charging the storage battery, and the other part is directly supplied to the electric device 400 to maintain the normal operation of the electric device. During the shadow period, the battery pack 300 supplies power to the electric device 400. And the lines of the solar cell set 100 supplying power to the battery pack 300 and the electric device 400 are called bus bars.

In order to ensure that the electric equipment 400 has stable power supply under any condition, a certain design is made on power supply strategies of the solar battery pack 100 and the storage battery pack 300 in an illumination period and a shadow period, during the illumination period, the power generated by the solar battery pack 100 is preferentially supplied to the electric equipment 400 for use, when the output power of the solar battery pack 100 is greater than the actual load demand of the electric equipment 400, the redundant power is charged into the storage battery pack 300 for storage, and when the power generated by the solar battery pack 100 is insufficient to supply other use demands of the electric equipment, the storage battery pack 300 assists in supplying power to the electric equipment 400 so as to ensure the power demand of the electric equipment 400. Meanwhile, in order to minimize the overcharge and overdischarge of the single cells in the battery pack 300, it is necessary to perform more precise control and management on the charging and discharging processes of the battery pack 300.

In order to realize the functions of controlling the solar cell set 100 and the storage battery set 300 to supply power to the electric equipment 400 and manage charging and discharging of the storage battery set 300 according to the above power supply strategy during the light period and the shadow period, the power module provided by the present invention is further provided with a control management module 200 (shown in fig. 2), the control management module 200 is composed of at least two special IC chips 210 with MPPT function and their supporting circuits, two of the special IC chips 210 having MPPT function are identical in at least function, so that there are two complete sets of IC chips 210 for control management purposes in the entire control management module 200, the integrated control IC chip 210 is used for forming mutual insurance by using two sets of same control IC chips 210 in a severe and complicated space environment, and the condition that the whole satellite electric equipment 400 cannot be normally powered on for use or the power supply is overloaded after one IC chip 210 is damaged is prevented. Preferably, a status check circuit is disposed in the control management module 200, and the status check circuit is electrically connected to all the IC chips 210, and detects whether one of the IC chips 210 is operating normally, and if it is detected that the IC chip 210 has no signal flowing out, cannot operate, and the like, it is determined that the IC chip 210 is damaged, and at this time, the status check circuit selects to start another backup IC chip 210 to operate.

The IC chip 210 has integrated thereon functions for managing the output power of the solar cell module 100, including functions for detecting the output current and the output voltage of the solar cell module 100. The IC chip 210 is electrically connected to the solar cell module 100, so that the IC chip 210 can detect the output current and the output voltage of the solar cell module 100 in real time and utilize the detected related data to the next MPPT calculation step.

The IC chip 210 performs decision calculation on the output current and the output voltage collected from the solar cell set 100 by using the MPPT algorithm built therein to form at least one optimum MPPT control command for controlling the output efficiency of the solar cell set 100. The MPPT algorithm can adopt a relatively mature disturbance observation method in the industry, the working principle is that the output power of the current solar battery pack 100 is measured, then a small voltage component disturbance is added to the original output voltage, the output power can be changed, the power after the change is measured, and the change direction of the power can be obtained by comparing the power before the change with the power before the change. If the power is increased, the original disturbance is continuously used, and if the power is reduced, the disturbance direction is changed. The MPPT chip cannot calculate the optimum MPPT control command once at this time, but needs to form the optimum MPPT control command through the varied power feedback after at least one small perturbation is performed.

The MPPT controller is called "maximum power point tracking" throughout, and can detect the generated voltage of the solar cell set in real time, and track the maximum voltage current Value (VI), so that the system is output to the power supply loop at maximum power.

The IC chip 210 also integrates a function for managing the charging of the battery pack 300, and the function also includes detecting a voltage signal and a current signal of the battery pack 300. The IC chip 210 is electrically connected to the battery pack 300, so that the IC chip 210 can detect a current signal and a voltage signal of the battery pack 300 in real time and utilize the detected related data to the subsequent formation of a charge control command. The current signal and the voltage signal may be current and voltage values of the charging of the battery pack 300.

The IC chip 210 can perform decision calculation on the current signal and the voltage signal collected from the battery pack 300 by using a charging control strategy program built therein to form at least one optimal charging control command for controlling charging of the battery pack 300. The storage battery pack 300 can work under proper charging power or voltage, and the problem of service life reduction of the storage battery pack 300 caused by over-charging and over-discharging of the storage battery pack 300 is effectively solved.

In order to implement the above-mentioned optimal MPPT control command and optimal charging control command, the control management module 200 further includes a control loop 220, and the control loop 220 is electrically connected to the IC chip 210, and simultaneously electrically connected to the solar battery pack 100 and the storage battery pack 300, so that the control loop 220 can control the output efficiency of the solar battery pack 100 and/or the charging mode of the storage battery pack 300 according to the optimal MPPT control command and the optimal charging control command received from the IC chip 210. The control method can be realized by the combined action of several DC-DC converters arranged in the control loop 220, and the DC-DC converters can adjust the related power output and charging voltage in a voltage boosting and reducing manner to realize charging modes such as constant current charging and constant power charging.

Preferably, the control circuit 220 is implemented with an IC chip to achieve higher integration and refinement.

The MPPT function of the IC chip 210 is a maximum power point tracking technique, which can monitor the discharge voltage of the solar cell array 100 in real time and track the maximum voltage and current values, so that the solar cell array 100 can keep charging the storage battery 300 with the maximum power, thereby improving the effective utilization rate of the power generated by the solar cell array 100. In some embodiments, the overall output efficiency of the solar cell array 100 can be increased to over 90% by removing the transmission loss, which greatly increases the working efficiency of the power module provided by the present invention.

In addition, an SOC detection unit 211 is integrated on the IC chip 210, and the SOC detection unit 211 is electrically connected to the battery pack 300 and used for calculating the remaining capacity of the battery according to the detected charge-discharge voltage of the battery pack 300 by means of numerical fitting or the like. In some embodiments, the calculated remaining power may also be used to adjust the load intensity of the power-consuming equipment 400 located on the satellite in real time, so that in the case that the power photoelectrically converted by the solar battery 100 is insufficient for the power-consuming equipment 400 to be used and the remaining power of the battery pack 300 is low, the power-consuming equipment 400 is properly controlled to reduce the power-consuming load through its electrical connection with the control circuit 220, so as to meet the minimum working requirement of the satellite.

The IC chip 210 can be fabricated into chip-scale devices, thereby greatly simplifying external devices and improving the integration level, so that the volume of the power module provided by the invention can be further reduced. Meanwhile, the IC chip 210 has a relatively wide application range, and input requirements of various solar cell sets 100 and input requirements of various storage battery packs 300 can be met by simply adjusting matching parameters of peripheral circuits of the IC chip, so that relatively high universality and expansibility are achieved.

In addition, the IC chip 210 can also control the input voltage of the solar battery pack 100 flowing to the storage battery pack 300, so that the storage battery pack 300 can be charged and discharged according to a suitable current/voltage sharing or fixed power, the overcharge and overdischarge conditions of the storage battery pack 300 are reduced, and the service life of the storage battery pack 300 is prolonged.

In some preferred embodiments, the units involved in the IC chip 210 are not divided according to specific physical unit modules, but are divided according to functions, that is, all functions thereof can be realized by one IC chip as a whole, and the internal circuit division thereof may not be strictly performed according to the above embodiments.

The voltage of a common solar cell single sheet is usually about 0.4 to 0.7V, even if a high-performance solar cell panel used by a satellite is in a lower single-cell voltage range, a solar cell panel formed by the solar cell panel is required to be arranged in series in order to enable the solar cell panel to meet the working voltage of electric equipment, the common solar cell arrangement mode is serial 36/54/60, and if the voltage of each solar cell single sheet is 0.5V, the total voltage of the solar cell panel under the arrangement schemes is about 18/27/30V.

The series connection of solar panels can boost the voltage of the total cell set, but there are also some problems. According to the short plate effect, when a certain solar cell panel or a plurality of solar cell panels in the solar cell set are under-illuminated, for example, in a shadow position, the current of the solar cell set is greatly reduced, and the total current is determined by the solar cell panel with the minimum current generated in the whole series-connected cell set. Although a plurality of groups of solar battery packs can be connected in parallel to prevent the current from decreasing, firstly, the designs increase the volume of the whole satellite power generation unit, and the satellite field with strict requirements on volume and weight can have the problem of inapplicability, and secondly, the solar battery packs connected in parallel are only a remedy measure, and the power of the solar battery packs shaded by shadows is still completely lost.

Therefore, the solar battery pack in the present apparatus is provided as a combination of a plurality of solar battery cells, and for example, may be provided as a combination of 3 solar battery cells. Two series-connected battery packs can be used in each solar cell unit, for example, the first solar cell unit includes a first series-connected solar cell string and a second series-connected solar cell string.

At least one bypass safety part is arranged in parallel on one of the two solar cell strings or one of the two solar cell parts, the bypass safety part can be arranged in a diode mode, and the bypass safety part is arranged beside the solar cell circuit in parallel in a mode of polarity opposite to that of the solar cell. The parallel connection beside the solar battery unit does not mean that one solar battery unit only has one bypass safety part, but a battery string or a certain part of battery cells in the solar battery unit can be connected with one bypass safety part in parallel.

The above-mentioned opposite polarities mean that when the solar cell string is normally generating electricity and forming a standard voltage, the solar cell string can be arranged in the circuit in a forward bias manner, and the bypass safety part is connected in parallel beside the solar cell unit in a reverse bias manner. In the principle of the electronic circuit, forward bias and reverse bias can both represent the arrangement modes of the diodes classified according to the current conducting direction, wherein the forward bias refers to connecting the anode of the diode to a high potential end and connecting the cathode of the diode to a low potential end, so that the bypass safety part can conduct current; similarly, the setting direction of the reverse bias and the forward bias is opposite, the anode of the reverse bias is connected with the low potential end, the cathode of the reverse bias is connected with the high potential end, and the bypass safety part is not conducted under the normal condition. However, when a certain solar cell unit is shaded by a shadow and cannot generate electricity or the voltage is low, the bypass safety part arranged in a reverse bias mode becomes a forward bias mode due to the fact that the voltage of the solar cell units connected in parallel is reduced, namely the potential of the high-potential end connected with the negative electrode of the bypass safety part is lower than that of the low-potential end connected with the positive electrode of the bypass safety part, and then the bypass safety part is conducted at the moment, so that the current generated by other solar cell units can flow through a circuit where the bypass safety part is located. The design avoids the problems that the part shielded by the shadow has high internal resistance and generates a large amount of heat when current passes through the part shielded by the shadow.

The first solar cell string and the second solar cell string can both adopt similar designs to improve the balance of each solar cell unit, for example, the number of panels and the lighting area of the two solar cell strings are set to be the same or similar, so that the open-circuit voltages of the two solar cell strings are basically consistent.

The interior of each solar cell unit can be arranged in a mode that two solar cells are connected in series and are externally connected with a bypass safety part in parallel, and a plurality of groups of solar cell units are connected in series together to form a solar cell group. In the field of satellites, it is most common that each solar cell unit is arranged around a satellite main body in the form of a solar panel, and generally, the solar panel is divided into two foldable solar panels arranged on the left and right of the satellite, or is a component on the panel. In addition, for some miniature satellites with smaller size and higher integration degree, the solar battery units can be arranged on the peripheral side surfaces of the satellite in a patch manner, for example, if the satellite body is designed into a box-shaped structure with a cuboid approximately, the solar battery units can be arranged on the four peripheral side surfaces of the satellite, and even can be arranged on the two top surfaces of the satellite under certain conditions.

Because the satellite is in a space gravity-free state and in the moving process of surrounding the earth, the operation attitude of the satellite is changed at any time, and certain satellites with earlier structural prototype designs or micro-satellites without solar sailboards are influenced by the gravity action of a plurality of large-mass celestial bodies in space and can generate autorotation. Some geosynchronous satellites in real-time communication with the ground or in real-time monitoring use a method of setting the rotation axis of the satellite to be parallel to the rotation axis of the earth and setting the rotation period of the satellite to be equal to the rotation period of the earth to ensure that a signal transmitter or monitoring equipment on the geosynchronous satellites can be aligned to the ground at any moment, but the satellites inevitably produce some attitude changes during operation, especially in an illuminator.

When the solar battery unit or the solar battery units arranged on the solar battery units are covered by the shadows of other parts on the body of the solar battery unit or the solar battery units arranged on the solar battery units are covered by the shadows due to the rotation of the satellite or slight attitude change of the satellite, the bypass safety part on the solar battery unit or the solar battery units covered by the shadows starts to work to conduct current, and the electricity generated by other solar battery units in full illumination can be output to electric equipment in a mode of large power output. In addition, the invention also provides a method for driving the solar cell under full illumination to discharge by using the on-off signal of the bypass safety part so as to adjust the satellite attitude and enable the shielded solar cell unit to be under illumination again.

Specifically, the invention further provides a state detection part, which is arranged near each solar cell unit, can be connected to a circuit where the bypass safety part is located in parallel, and is configured to detect whether the bypass safety part is in an open state, and an open-close signal of the state detection part can be expressed by adopting two levels, namely a high level and a low level. The opening and closing signal is transmitted to the control management module, and the control management module can be provided with an additional processing chip or directly utilizes other pins of the IC chip and an additionally written judgment program to judge the opening and closing condition of the bypass safety part. The bypass safety part of each solar cell unit is provided with a corresponding number, when the control management module judges that a signal of opening the bypass safety part with a certain number indicates that at least one part of the position of the solar cell unit is in a shadow shielding state, the control management module controls the actuating mechanism of the satellite solar sailboard to move, so that the operation attitude of the satellite is adjusted, particularly the adjustment of the rotation angle and the lifting height of the solar sailboard, when the control management module detects that the bypass safety part with the certain number is in a closing signal, the shadow shielding at the position is removed, and the attitude adjustment process is ended. Preferably, in the process of adjusting the posture, the actuating mechanism controlling each solar cell unit is bound, and specifically, when a bypass safety part with a certain number has a turn-on signal, the corresponding actuating mechanism is controlled to rotate or tilt, so that the illumination condition at the position is adjusted. Preferably, the electric power for controlling the actuating mechanism to move comes from the solar cell unit which does not detect the opening of the bypass safety part, and the design has the advantages that the solar cell unit with high illumination intensity and coverage is used as the driving output unit, so that the electric quantity which is generated by the solar cell unit and is more than that generated by the solar cell unit which is shielded by the shadow is consumed by the actuating mechanism, the passive balancing effect of the energy generating unit is realized, the balance of the whole power supply equipment is ensured, the unbalance condition that the electric energy of some storage batteries is insufficient and the electric energy of other storage batteries is too high is avoided, and the service life of the satellite can be effectively prolonged.

In consideration of the MPPT algorithm adopted previously in the present invention to find the maximum power output point of the solar cell to control the output thereof, the maximum power output point found by the solar cell on the satellite may vary somewhat in case of shading that may occur to the solar cell. Specifically, in the solar cell units formed in series, if some solar cell panels on a certain solar cell string are affected by the change of the satellite attitude and are shielded by light, the output power of the solar cell will be affected. It is to be clearly explained that the change process needs to define three states, the non-shielding state refers to a state where the solar cell unit completely irradiates sunlight and is not shielded by a shadow, the semi-shielding state refers to a state where a certain part on the solar cell unit is shielded by a certain shadow but the potential change caused on the bypass safety part is not enough to enable the bypass safety part to generate forward and reverse bias conversion, and the full-shielding state refers to a state where a certain part on the solar cell unit is shielded by a shadow in an area enough to enable the bypass safety part to generate forward and reverse bias conversion so as to be conducted. Due to the characteristics of the MPPT algorithm, the maximum power output point of the whole solar cell unit is searched at the time, so as shown in fig. 3, when the solar cell unit is in an unshaded state, the solar cell unit has the maximum power generation efficiency and the highest output power, the MPPT is a unimodal curve, and the highest output power point can be called as a first output power point a; when the solar cell is in a semi-shading state, because the bypass safety part is not opened, the solar cell unit formed by series connection greatly reduces the overall output power due to the influence of the shaded solar cell panel, the MPPT is a double-peak curve, the output power peak value searched by the algorithm is possibly in a smaller non-maximum value position, and the point can be called as a second output power point B; when the solar cell is in the fully-shielded state, since the bypass fuse is turned on, the partial cell is discharged out of the circuit, so that the output characteristic of the whole solar cell is similar to that in the non-shielded state, the peak output power point searched by the MPPT algorithm will be increased, but due to the influence of the discharge of the partial cell, the output power of the partial cell does not reach the maximum output power in the non-shielded state, but is slightly smaller, and this point may be referred to as a third power output point C.

Since the attitude of the satellite in the orbital motion is not completely constant, the time for the solar cell to be in the half-shielding state may be long, because it cannot be guaranteed that the satellite is slightly deflected due to a slight external force during the stable operation. Therefore, in some cases, the discharge power of the whole solar cell unit is at a low level for a long time and cannot meet the power demand of the satellite because the bypass safety part is not opened for a long time or the battery unit is not restored to the unshielded state for a long time.

Therefore, in combination with the three states of the solar battery cells, the energy supply module of the present invention has a function of preventing the solar battery cells from being in a half-shading state for a long time. The control management module detects the change of the maximum power output point searched by the MPPT algorithm and/or the opening and closing condition of the bypass safety part so as to start the actuating mechanism to drive the solar cell module in the half shielding state to change to the full shielding state or the non-shielding state when the solar cell unit is judged to be switched from the full shielding state to the half shielding state or from the non-shielding state to the half shielding state. The actuating mechanism can adopt a driving structure that a rotating disc, an air jet and the like can change the satellite attitude, or at least can change the illumination condition of the surface of the solar cell unit.

The above functions are obtained in consideration of the situation that the electric appliances on the satellite need higher power to drive at any time, and in fact, for some satellites with different functions, a large amount of power is not needed for supporting the satellites within a certain period of time, and even in order to prevent the risk of overcharging of the storage battery pack for storing energy, the solar battery unit needs to be subjected to power reduction treatment. Therefore, for different time periods and possibly different power requirements under different conditions on the satellite, the actuating mechanism in the invention can maintain at least one solar cell unit in a fully-shielded, semi-shielded or non-shielded state to obtain different output power under the control of the MPPT algorithm, wherein the change of the maximum power point and the change sequence from non-shielding to full shielding are in a nonlinear relationship. The MPPT algorithm herein may employ a general single-peak algorithm such as a perturbation observation method, and preferably, its initial perturbation direction is set to a direction from a large potential to a small potential.

It should be noted that the above-mentioned embodiments are exemplary, and that those skilled in the art, having benefit of the present disclosure, may devise various arrangements that are within the scope of the present disclosure and that fall within the scope of the invention. It should be understood by those skilled in the art that the present specification and figures are illustrative only and are not limiting upon the claims. The scope of the invention is defined by the claims and their equivalents.

Claims (10)

1. A satellite solar power module system, comprising:

a solar cell set (100) comprising a plurality of solar cell units,

a bypass safety part is arranged in the solar cell unit, when the bypass safety part is communicated, the solar cell sheets which are connected with the bypass safety part in parallel are excluded from a power supply circuit of the solar cell unit,

the output end of each solar cell unit is provided with an MPPT unit which utilizes an MPPT algorithm to maintain the output power of the solar cell unit at a maximum output power point (A, B, C),

it is characterized in that the preparation method is characterized in that,

an actuating mechanism is provided and is configured to be capable of maintaining at least one solar cell in a fully shielded, half shielded or non-shielded state to obtain a maximum output power point (A, B, C) for a current shielded state under the control of an MPPT algorithm, wherein a numerical variation trend of the maximum output power point (A, B, C) of each cell is different from a variation trend of a light receiving area of each cell brought from non-shielded to fully shielded.

2. The modular system of claim 1 further comprising a control management module electrically connected to the solar cell output and the bypass fuse, wherein the control management module determines whether the solar cell is in the fully shielded, semi-shielded or un-shielded state by detecting and determining a change in the output power of the solar cell and the on/off condition of the bypass fuse.

3. The modular system of claim 2, wherein the control management module detects a change in a maximum power output point found by the MPPT algorithm and/or an opening/closing condition of the bypass fuse to actuate the actuating mechanism to drive the solar cell module in the half-shielding state to change to the full-shielding state or the non-shielding state when it is determined that the solar cell unit is changed from the full-shielding state to the half-shielding state or from the non-shielding state to the half-shielding state, in case that the power consumption of the power consumption equipment in the satellite requires a large power for a long time.

4. The modular system of claim 3 wherein said bypass fuse is disposed in parallel on said solar cell circuit in a polarity opposite to that of said solar cells.

5. The modular system of claim 4 wherein the power source for driving the actuating mechanism is provided by the unshielded solar cells of the solar cell array.

6. The modular system according to claim 5, wherein the control management module (200) determines a maximum power output point of the energy production unit according to the variation of the collected bus voltage and bus current in combination with an MPPT algorithm, and controls the output voltage of the energy production unit to be changed to an appropriate bus voltage based on the determined maximum power output point, so as to realize a maximum power output mode of the solar cell set (100).

7. The modular system according to claim 6, characterized in that said control and management module (200) is composed of at least two mutually backed-up IC chips (210), said IC chips (210) being functionally identical at least in terms of collecting electrical data of the solar cell set (100) and the bus and controlling the output power of the solar cell set (100) by way of MPPT.

8. The module system according to claim 7, wherein the control management module (200) further comprises a state detection circuit, at least one of the IC chips (210) is in an operating state, and when the state detection circuit detects that the operating IC chip (210) is in a damaged state, the other IC chips (210) are controlled to enter the operating state.

9. The modular system of claim 8, wherein said control and management module (200) adjusts said output voltage of said solar cell module (100) by means of voltage boosting and dropping.

10. The module system according to claim 9, wherein the control management module (200) controls the charging mode of the secondary battery pack (300) by detecting the charging current and the charging voltage of the secondary battery pack (300) so that the secondary battery pack is prevented from being overcharged.

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